rbd.c 167.2 KB
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/*
   rbd.c -- Export ceph rados objects as a Linux block device


   based on drivers/block/osdblk.c:

   Copyright 2009 Red Hat, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.



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   For usage instructions, please refer to:
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                 Documentation/ABI/testing/sysfs-bus-rbd
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 */

#include <linux/ceph/libceph.h>
#include <linux/ceph/osd_client.h>
#include <linux/ceph/mon_client.h>
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#include <linux/ceph/cls_lock_client.h>
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#include <linux/ceph/decode.h>
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#include <linux/parser.h>
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#include <linux/bsearch.h>
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#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
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#include <linux/blk-mq.h>
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#include <linux/fs.h>
#include <linux/blkdev.h>
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#include <linux/slab.h>
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#include <linux/idr.h>
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#include <linux/workqueue.h>
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#include "rbd_types.h"

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#define RBD_DEBUG	/* Activate rbd_assert() calls */

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/*
 * The basic unit of block I/O is a sector.  It is interpreted in a
 * number of contexts in Linux (blk, bio, genhd), but the default is
 * universally 512 bytes.  These symbols are just slightly more
 * meaningful than the bare numbers they represent.
 */
#define	SECTOR_SHIFT	9
#define	SECTOR_SIZE	(1ULL << SECTOR_SHIFT)

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/*
 * Increment the given counter and return its updated value.
 * If the counter is already 0 it will not be incremented.
 * If the counter is already at its maximum value returns
 * -EINVAL without updating it.
 */
static int atomic_inc_return_safe(atomic_t *v)
{
	unsigned int counter;

	counter = (unsigned int)__atomic_add_unless(v, 1, 0);
	if (counter <= (unsigned int)INT_MAX)
		return (int)counter;

	atomic_dec(v);

	return -EINVAL;
}

/* Decrement the counter.  Return the resulting value, or -EINVAL */
static int atomic_dec_return_safe(atomic_t *v)
{
	int counter;

	counter = atomic_dec_return(v);
	if (counter >= 0)
		return counter;

	atomic_inc(v);

	return -EINVAL;
}

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#define RBD_DRV_NAME "rbd"
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#define RBD_MINORS_PER_MAJOR		256
#define RBD_SINGLE_MAJOR_PART_SHIFT	4
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#define RBD_MAX_PARENT_CHAIN_LEN	16

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#define RBD_SNAP_DEV_NAME_PREFIX	"snap_"
#define RBD_MAX_SNAP_NAME_LEN	\
			(NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))

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#define RBD_MAX_SNAP_COUNT	510	/* allows max snapc to fit in 4KB */
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#define RBD_SNAP_HEAD_NAME	"-"

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#define	BAD_SNAP_INDEX	U32_MAX		/* invalid index into snap array */

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/* This allows a single page to hold an image name sent by OSD */
#define RBD_IMAGE_NAME_LEN_MAX	(PAGE_SIZE - sizeof (__le32) - 1)
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#define RBD_IMAGE_ID_LEN_MAX	64
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#define RBD_OBJ_PREFIX_LEN_MAX	64
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#define RBD_NOTIFY_TIMEOUT	5	/* seconds */
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#define RBD_RETRY_DELAY		msecs_to_jiffies(1000)

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/* Feature bits */

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#define RBD_FEATURE_LAYERING	(1<<0)
#define RBD_FEATURE_STRIPINGV2	(1<<1)
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#define RBD_FEATURE_EXCLUSIVE_LOCK (1<<2)
#define RBD_FEATURES_ALL	(RBD_FEATURE_LAYERING |		\
				 RBD_FEATURE_STRIPINGV2 |	\
				 RBD_FEATURE_EXCLUSIVE_LOCK)
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/* Features supported by this (client software) implementation. */

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#define RBD_FEATURES_SUPPORTED	(RBD_FEATURES_ALL)
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/*
 * An RBD device name will be "rbd#", where the "rbd" comes from
 * RBD_DRV_NAME above, and # is a unique integer identifier.
 */
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#define DEV_NAME_LEN		32

/*
 * block device image metadata (in-memory version)
 */
struct rbd_image_header {
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	/* These six fields never change for a given rbd image */
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	char *object_prefix;
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	__u8 obj_order;
	__u8 crypt_type;
	__u8 comp_type;
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	u64 stripe_unit;
	u64 stripe_count;
	u64 features;		/* Might be changeable someday? */
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	/* The remaining fields need to be updated occasionally */
	u64 image_size;
	struct ceph_snap_context *snapc;
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	char *snap_names;	/* format 1 only */
	u64 *snap_sizes;	/* format 1 only */
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};

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/*
 * An rbd image specification.
 *
 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
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 * identify an image.  Each rbd_dev structure includes a pointer to
 * an rbd_spec structure that encapsulates this identity.
 *
 * Each of the id's in an rbd_spec has an associated name.  For a
 * user-mapped image, the names are supplied and the id's associated
 * with them are looked up.  For a layered image, a parent image is
 * defined by the tuple, and the names are looked up.
 *
 * An rbd_dev structure contains a parent_spec pointer which is
 * non-null if the image it represents is a child in a layered
 * image.  This pointer will refer to the rbd_spec structure used
 * by the parent rbd_dev for its own identity (i.e., the structure
 * is shared between the parent and child).
 *
 * Since these structures are populated once, during the discovery
 * phase of image construction, they are effectively immutable so
 * we make no effort to synchronize access to them.
 *
 * Note that code herein does not assume the image name is known (it
 * could be a null pointer).
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 */
struct rbd_spec {
	u64		pool_id;
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	const char	*pool_name;
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	const char	*image_id;
	const char	*image_name;
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	u64		snap_id;
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	const char	*snap_name;
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	struct kref	kref;
};

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/*
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 * an instance of the client.  multiple devices may share an rbd client.
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 */
struct rbd_client {
	struct ceph_client	*client;
	struct kref		kref;
	struct list_head	node;
};

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struct rbd_img_request;
typedef void (*rbd_img_callback_t)(struct rbd_img_request *);

#define	BAD_WHICH	U32_MAX		/* Good which or bad which, which? */

struct rbd_obj_request;
typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);

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enum obj_request_type {
	OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
};
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enum obj_operation_type {
	OBJ_OP_WRITE,
	OBJ_OP_READ,
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	OBJ_OP_DISCARD,
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};

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enum obj_req_flags {
	OBJ_REQ_DONE,		/* completion flag: not done = 0, done = 1 */
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	OBJ_REQ_IMG_DATA,	/* object usage: standalone = 0, image = 1 */
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	OBJ_REQ_KNOWN,		/* EXISTS flag valid: no = 0, yes = 1 */
	OBJ_REQ_EXISTS,		/* target exists: no = 0, yes = 1 */
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};

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struct rbd_obj_request {
	const char		*object_name;
	u64			offset;		/* object start byte */
	u64			length;		/* bytes from offset */
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	unsigned long		flags;
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	/*
	 * An object request associated with an image will have its
	 * img_data flag set; a standalone object request will not.
	 *
	 * A standalone object request will have which == BAD_WHICH
	 * and a null obj_request pointer.
	 *
	 * An object request initiated in support of a layered image
	 * object (to check for its existence before a write) will
	 * have which == BAD_WHICH and a non-null obj_request pointer.
	 *
	 * Finally, an object request for rbd image data will have
	 * which != BAD_WHICH, and will have a non-null img_request
	 * pointer.  The value of which will be in the range
	 * 0..(img_request->obj_request_count-1).
	 */
	union {
		struct rbd_obj_request	*obj_request;	/* STAT op */
		struct {
			struct rbd_img_request	*img_request;
			u64			img_offset;
			/* links for img_request->obj_requests list */
			struct list_head	links;
		};
	};
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	u32			which;		/* posn image request list */

	enum obj_request_type	type;
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	union {
		struct bio	*bio_list;
		struct {
			struct page	**pages;
			u32		page_count;
		};
	};
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	struct page		**copyup_pages;
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	u32			copyup_page_count;
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	struct ceph_osd_request	*osd_req;

	u64			xferred;	/* bytes transferred */
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	int			result;
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	rbd_obj_callback_t	callback;
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	struct completion	completion;
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	struct kref		kref;
};

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enum img_req_flags {
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	IMG_REQ_WRITE,		/* I/O direction: read = 0, write = 1 */
	IMG_REQ_CHILD,		/* initiator: block = 0, child image = 1 */
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	IMG_REQ_LAYERED,	/* ENOENT handling: normal = 0, layered = 1 */
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	IMG_REQ_DISCARD,	/* discard: normal = 0, discard request = 1 */
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};

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struct rbd_img_request {
	struct rbd_device	*rbd_dev;
	u64			offset;	/* starting image byte offset */
	u64			length;	/* byte count from offset */
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	unsigned long		flags;
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	union {
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		u64			snap_id;	/* for reads */
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		struct ceph_snap_context *snapc;	/* for writes */
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	};
	union {
		struct request		*rq;		/* block request */
		struct rbd_obj_request	*obj_request;	/* obj req initiator */
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	};
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	struct page		**copyup_pages;
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	u32			copyup_page_count;
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	spinlock_t		completion_lock;/* protects next_completion */
	u32			next_completion;
	rbd_img_callback_t	callback;
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	u64			xferred;/* aggregate bytes transferred */
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	int			result;	/* first nonzero obj_request result */
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	u32			obj_request_count;
	struct list_head	obj_requests;	/* rbd_obj_request structs */

	struct kref		kref;
};

#define for_each_obj_request(ireq, oreq) \
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	list_for_each_entry(oreq, &(ireq)->obj_requests, links)
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#define for_each_obj_request_from(ireq, oreq) \
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	list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
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#define for_each_obj_request_safe(ireq, oreq, n) \
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	list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
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enum rbd_watch_state {
	RBD_WATCH_STATE_UNREGISTERED,
	RBD_WATCH_STATE_REGISTERED,
	RBD_WATCH_STATE_ERROR,
};

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enum rbd_lock_state {
	RBD_LOCK_STATE_UNLOCKED,
	RBD_LOCK_STATE_LOCKED,
	RBD_LOCK_STATE_RELEASING,
};

/* WatchNotify::ClientId */
struct rbd_client_id {
	u64 gid;
	u64 handle;
};

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struct rbd_mapping {
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	u64                     size;
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	u64                     features;
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	bool			read_only;
};

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/*
 * a single device
 */
struct rbd_device {
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	int			dev_id;		/* blkdev unique id */
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	int			major;		/* blkdev assigned major */
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	int			minor;
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	struct gendisk		*disk;		/* blkdev's gendisk and rq */

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	u32			image_format;	/* Either 1 or 2 */
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	struct rbd_client	*rbd_client;

	char			name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */

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	spinlock_t		lock;		/* queue, flags, open_count */
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	struct rbd_image_header	header;
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	unsigned long		flags;		/* possibly lock protected */
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	struct rbd_spec		*spec;
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	struct rbd_options	*opts;
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	char			*config_info;	/* add{,_single_major} string */
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	struct ceph_object_id	header_oid;
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	struct ceph_object_locator header_oloc;
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	struct ceph_file_layout	layout;		/* used for all rbd requests */
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	struct mutex		watch_mutex;
	enum rbd_watch_state	watch_state;
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	struct ceph_osd_linger_request *watch_handle;
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	u64			watch_cookie;
	struct delayed_work	watch_dwork;
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	struct rw_semaphore	lock_rwsem;
	enum rbd_lock_state	lock_state;
	struct rbd_client_id	owner_cid;
	struct work_struct	acquired_lock_work;
	struct work_struct	released_lock_work;
	struct delayed_work	lock_dwork;
	struct work_struct	unlock_work;
	wait_queue_head_t	lock_waitq;

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	struct workqueue_struct	*task_wq;
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	struct rbd_spec		*parent_spec;
	u64			parent_overlap;
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	atomic_t		parent_ref;
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	struct rbd_device	*parent;
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	/* Block layer tags. */
	struct blk_mq_tag_set	tag_set;

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	/* protects updating the header */
	struct rw_semaphore     header_rwsem;
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	struct rbd_mapping	mapping;
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	struct list_head	node;
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	/* sysfs related */
	struct device		dev;
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	unsigned long		open_count;	/* protected by lock */
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};

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/*
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 * Flag bits for rbd_dev->flags:
 * - REMOVING (which is coupled with rbd_dev->open_count) is protected
 *   by rbd_dev->lock
 * - BLACKLISTED is protected by rbd_dev->lock_rwsem
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 */
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enum rbd_dev_flags {
	RBD_DEV_FLAG_EXISTS,	/* mapped snapshot has not been deleted */
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	RBD_DEV_FLAG_REMOVING,	/* this mapping is being removed */
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	RBD_DEV_FLAG_BLACKLISTED, /* our ceph_client is blacklisted */
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};

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static DEFINE_MUTEX(client_mutex);	/* Serialize client creation */
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static LIST_HEAD(rbd_dev_list);    /* devices */
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static DEFINE_SPINLOCK(rbd_dev_list_lock);

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static LIST_HEAD(rbd_client_list);		/* clients */
static DEFINE_SPINLOCK(rbd_client_list_lock);
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/* Slab caches for frequently-allocated structures */

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static struct kmem_cache	*rbd_img_request_cache;
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static struct kmem_cache	*rbd_obj_request_cache;
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static struct kmem_cache	*rbd_segment_name_cache;
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static int rbd_major;
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static DEFINE_IDA(rbd_dev_id_ida);

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static struct workqueue_struct *rbd_wq;

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/*
 * Default to false for now, as single-major requires >= 0.75 version of
 * userspace rbd utility.
 */
static bool single_major = false;
module_param(single_major, bool, S_IRUGO);
MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: false)");

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static int rbd_img_request_submit(struct rbd_img_request *img_request);

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static ssize_t rbd_add(struct bus_type *bus, const char *buf,
		       size_t count);
static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
			  size_t count);
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static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf,
				    size_t count);
static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
				       size_t count);
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static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
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static void rbd_spec_put(struct rbd_spec *spec);
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static int rbd_dev_id_to_minor(int dev_id)
{
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	return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
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}

static int minor_to_rbd_dev_id(int minor)
{
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	return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
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}

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static bool rbd_is_lock_supported(struct rbd_device *rbd_dev)
{
	return (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	       rbd_dev->spec->snap_id == CEPH_NOSNAP &&
	       !rbd_dev->mapping.read_only;
}

static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
{
	return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
	       rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
}

static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
{
	bool is_lock_owner;

	down_read(&rbd_dev->lock_rwsem);
	is_lock_owner = __rbd_is_lock_owner(rbd_dev);
	up_read(&rbd_dev->lock_rwsem);
	return is_lock_owner;
}

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static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
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static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
static BUS_ATTR(remove_single_major, S_IWUSR, NULL, rbd_remove_single_major);
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static struct attribute *rbd_bus_attrs[] = {
	&bus_attr_add.attr,
	&bus_attr_remove.attr,
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	&bus_attr_add_single_major.attr,
	&bus_attr_remove_single_major.attr,
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	NULL,
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};
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static umode_t rbd_bus_is_visible(struct kobject *kobj,
				  struct attribute *attr, int index)
{
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	if (!single_major &&
	    (attr == &bus_attr_add_single_major.attr ||
	     attr == &bus_attr_remove_single_major.attr))
		return 0;

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	return attr->mode;
}

static const struct attribute_group rbd_bus_group = {
	.attrs = rbd_bus_attrs,
	.is_visible = rbd_bus_is_visible,
};
__ATTRIBUTE_GROUPS(rbd_bus);
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static struct bus_type rbd_bus_type = {
	.name		= "rbd",
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	.bus_groups	= rbd_bus_groups,
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};

static void rbd_root_dev_release(struct device *dev)
{
}

static struct device rbd_root_dev = {
	.init_name =    "rbd",
	.release =      rbd_root_dev_release,
};

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static __printf(2, 3)
void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;

	if (!rbd_dev)
		printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
	else if (rbd_dev->disk)
		printk(KERN_WARNING "%s: %s: %pV\n",
			RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
	else if (rbd_dev->spec && rbd_dev->spec->image_name)
		printk(KERN_WARNING "%s: image %s: %pV\n",
			RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
	else if (rbd_dev->spec && rbd_dev->spec->image_id)
		printk(KERN_WARNING "%s: id %s: %pV\n",
			RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
	else	/* punt */
		printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
			RBD_DRV_NAME, rbd_dev, &vaf);
	va_end(args);
}

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#ifdef RBD_DEBUG
#define rbd_assert(expr)						\
		if (unlikely(!(expr))) {				\
			printk(KERN_ERR "\nAssertion failure in %s() "	\
						"at line %d:\n\n"	\
					"\trbd_assert(%s);\n\n",	\
					__func__, __LINE__, #expr);	\
			BUG();						\
		}
#else /* !RBD_DEBUG */
#  define rbd_assert(expr)	((void) 0)
#endif /* !RBD_DEBUG */
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static void rbd_osd_copyup_callback(struct rbd_obj_request *obj_request);
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static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
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static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
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static int rbd_dev_refresh(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
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static int rbd_dev_header_info(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
595 596
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id);
597 598 599 600
static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u8 *order, u64 *snap_size);
static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
		u64 *snap_features);
601

602 603
static int rbd_open(struct block_device *bdev, fmode_t mode)
{
A
Alex Elder 已提交
604
	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
605
	bool removing = false;
606

A
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607
	if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
608 609
		return -EROFS;

610
	spin_lock_irq(&rbd_dev->lock);
611 612 613 614
	if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
		removing = true;
	else
		rbd_dev->open_count++;
615
	spin_unlock_irq(&rbd_dev->lock);
616 617 618
	if (removing)
		return -ENOENT;

A
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619
	(void) get_device(&rbd_dev->dev);
620

621 622 623
	return 0;
}

624
static void rbd_release(struct gendisk *disk, fmode_t mode)
625 626
{
	struct rbd_device *rbd_dev = disk->private_data;
627 628
	unsigned long open_count_before;

629
	spin_lock_irq(&rbd_dev->lock);
630
	open_count_before = rbd_dev->open_count--;
631
	spin_unlock_irq(&rbd_dev->lock);
632
	rbd_assert(open_count_before > 0);
633

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634
	put_device(&rbd_dev->dev);
635 636
}

G
Guangliang Zhao 已提交
637 638
static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
639
	int ret = 0;
G
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640 641
	int val;
	bool ro;
642
	bool ro_changed = false;
G
Guangliang Zhao 已提交
643

644
	/* get_user() may sleep, so call it before taking rbd_dev->lock */
G
Guangliang Zhao 已提交
645 646 647 648 649 650 651 652
	if (get_user(val, (int __user *)(arg)))
		return -EFAULT;

	ro = val ? true : false;
	/* Snapshot doesn't allow to write*/
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
		return -EROFS;

653 654 655 656 657 658 659
	spin_lock_irq(&rbd_dev->lock);
	/* prevent others open this device */
	if (rbd_dev->open_count > 1) {
		ret = -EBUSY;
		goto out;
	}

G
Guangliang Zhao 已提交
660 661
	if (rbd_dev->mapping.read_only != ro) {
		rbd_dev->mapping.read_only = ro;
662
		ro_changed = true;
G
Guangliang Zhao 已提交
663 664
	}

665 666 667 668 669 670 671
out:
	spin_unlock_irq(&rbd_dev->lock);
	/* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
	if (ret == 0 && ro_changed)
		set_disk_ro(rbd_dev->disk, ro ? 1 : 0);

	return ret;
G
Guangliang Zhao 已提交
672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698
}

static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
			unsigned int cmd, unsigned long arg)
{
	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
	int ret = 0;

	switch (cmd) {
	case BLKROSET:
		ret = rbd_ioctl_set_ro(rbd_dev, arg);
		break;
	default:
		ret = -ENOTTY;
	}

	return ret;
}

#ifdef CONFIG_COMPAT
static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
				unsigned int cmd, unsigned long arg)
{
	return rbd_ioctl(bdev, mode, cmd, arg);
}
#endif /* CONFIG_COMPAT */

699 700 701
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
702
	.release		= rbd_release,
G
Guangliang Zhao 已提交
703 704 705 706
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
707 708 709
};

/*
710
 * Initialize an rbd client instance.  Success or not, this function
711
 * consumes ceph_opts.  Caller holds client_mutex.
712
 */
713
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
714 715 716 717
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

A
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718
	dout("%s:\n", __func__);
719 720 721 722 723 724 725
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

	kref_init(&rbdc->kref);
	INIT_LIST_HEAD(&rbdc->node);

A
Alex Elder 已提交
726
	rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
727
	if (IS_ERR(rbdc->client))
728
		goto out_rbdc;
A
Alex Elder 已提交
729
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
730 731 732

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
733
		goto out_client;
734

A
Alex Elder 已提交
735
	spin_lock(&rbd_client_list_lock);
736
	list_add_tail(&rbdc->node, &rbd_client_list);
A
Alex Elder 已提交
737
	spin_unlock(&rbd_client_list_lock);
738

A
Alex Elder 已提交
739
	dout("%s: rbdc %p\n", __func__, rbdc);
740

741
	return rbdc;
742
out_client:
743
	ceph_destroy_client(rbdc->client);
744
out_rbdc:
745 746
	kfree(rbdc);
out_opt:
A
Alex Elder 已提交
747 748
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
A
Alex Elder 已提交
749 750
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
751
	return ERR_PTR(ret);
752 753
}

754 755 756 757 758 759 760
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

761
/*
762 763
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
764
 */
765
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
766 767
{
	struct rbd_client *client_node;
768
	bool found = false;
769

A
Alex Elder 已提交
770
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
771 772
		return NULL;

773 774 775
	spin_lock(&rbd_client_list_lock);
	list_for_each_entry(client_node, &rbd_client_list, node) {
		if (!ceph_compare_options(ceph_opts, client_node->client)) {
776 777
			__rbd_get_client(client_node);

778 779 780 781 782 783 784
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
785 786
}

787
/*
788
 * (Per device) rbd map options
789 790
 */
enum {
I
Ilya Dryomov 已提交
791
	Opt_queue_depth,
792 793 794 795
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
A
Alex Elder 已提交
796 797
	Opt_read_only,
	Opt_read_write,
I
Ilya Dryomov 已提交
798
	Opt_lock_on_read,
799
	Opt_err
800 801
};

A
Alex Elder 已提交
802
static match_table_t rbd_opts_tokens = {
I
Ilya Dryomov 已提交
803
	{Opt_queue_depth, "queue_depth=%d"},
804 805
	/* int args above */
	/* string args above */
A
Alex Elder 已提交
806
	{Opt_read_only, "read_only"},
A
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807 808 809
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
I
Ilya Dryomov 已提交
810
	{Opt_lock_on_read, "lock_on_read"},
811
	{Opt_err, NULL}
812 813
};

A
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814
struct rbd_options {
I
Ilya Dryomov 已提交
815
	int	queue_depth;
A
Alex Elder 已提交
816
	bool	read_only;
I
Ilya Dryomov 已提交
817
	bool	lock_on_read;
A
Alex Elder 已提交
818 819
};

I
Ilya Dryomov 已提交
820
#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
A
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821
#define RBD_READ_ONLY_DEFAULT	false
I
Ilya Dryomov 已提交
822
#define RBD_LOCK_ON_READ_DEFAULT false
A
Alex Elder 已提交
823

824 825
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
826
	struct rbd_options *rbd_opts = private;
827 828 829
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
Alex Elder 已提交
830
	token = match_token(c, rbd_opts_tokens, argstr);
831 832 833
	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
834
			pr_err("bad mount option arg (not int) at '%s'\n", c);
835 836 837 838
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
839
		dout("got string token %d val %s\n", token, argstr[0].from);
840 841 842 843 844
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
I
Ilya Dryomov 已提交
845 846 847 848 849 850 851
	case Opt_queue_depth:
		if (intval < 1) {
			pr_err("queue_depth out of range\n");
			return -EINVAL;
		}
		rbd_opts->queue_depth = intval;
		break;
A
Alex Elder 已提交
852 853 854 855 856 857
	case Opt_read_only:
		rbd_opts->read_only = true;
		break;
	case Opt_read_write:
		rbd_opts->read_only = false;
		break;
I
Ilya Dryomov 已提交
858 859 860
	case Opt_lock_on_read:
		rbd_opts->lock_on_read = true;
		break;
861
	default:
862 863
		/* libceph prints "bad option" msg */
		return -EINVAL;
864
	}
865

866 867 868
	return 0;
}

G
Guangliang Zhao 已提交
869 870 871 872 873 874 875
static char* obj_op_name(enum obj_operation_type op_type)
{
	switch (op_type) {
	case OBJ_OP_READ:
		return "read";
	case OBJ_OP_WRITE:
		return "write";
876 877
	case OBJ_OP_DISCARD:
		return "discard";
G
Guangliang Zhao 已提交
878 879 880 881 882
	default:
		return "???";
	}
}

883 884
/*
 * Get a ceph client with specific addr and configuration, if one does
885 886
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
887
 */
888
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
889
{
890
	struct rbd_client *rbdc;
891

892
	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
893
	rbdc = rbd_client_find(ceph_opts);
894
	if (rbdc)	/* using an existing client */
A
Alex Elder 已提交
895
		ceph_destroy_options(ceph_opts);
896
	else
897
		rbdc = rbd_client_create(ceph_opts);
898
	mutex_unlock(&client_mutex);
899

900
	return rbdc;
901 902 903 904
}

/*
 * Destroy ceph client
A
Alex Elder 已提交
905
 *
A
Alex Elder 已提交
906
 * Caller must hold rbd_client_list_lock.
907 908 909 910 911
 */
static void rbd_client_release(struct kref *kref)
{
	struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);

A
Alex Elder 已提交
912
	dout("%s: rbdc %p\n", __func__, rbdc);
913
	spin_lock(&rbd_client_list_lock);
914
	list_del(&rbdc->node);
915
	spin_unlock(&rbd_client_list_lock);
916 917 918 919 920 921 922 923 924

	ceph_destroy_client(rbdc->client);
	kfree(rbdc);
}

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
925
static void rbd_put_client(struct rbd_client *rbdc)
926
{
927 928
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
929 930
}

931 932 933 934 935
static bool rbd_image_format_valid(u32 image_format)
{
	return image_format == 1 || image_format == 2;
}

936 937
static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
{
938 939 940 941 942 943 944
	size_t size;
	u32 snap_count;

	/* The header has to start with the magic rbd header text */
	if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
		return false;

A
Alex Elder 已提交
945 946 947 948 949 950 951 952 953 954
	/* The bio layer requires at least sector-sized I/O */

	if (ondisk->options.order < SECTOR_SHIFT)
		return false;

	/* If we use u64 in a few spots we may be able to loosen this */

	if (ondisk->options.order > 8 * sizeof (int) - 1)
		return false;

955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972
	/*
	 * The size of a snapshot header has to fit in a size_t, and
	 * that limits the number of snapshots.
	 */
	snap_count = le32_to_cpu(ondisk->snap_count);
	size = SIZE_MAX - sizeof (struct ceph_snap_context);
	if (snap_count > size / sizeof (__le64))
		return false;

	/*
	 * Not only that, but the size of the entire the snapshot
	 * header must also be representable in a size_t.
	 */
	size -= snap_count * sizeof (__le64);
	if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
		return false;

	return true;
973 974
}

975
/*
976 977
 * Fill an rbd image header with information from the given format 1
 * on-disk header.
978
 */
A
Alex Elder 已提交
979
static int rbd_header_from_disk(struct rbd_device *rbd_dev,
980
				 struct rbd_image_header_ondisk *ondisk)
981
{
A
Alex Elder 已提交
982
	struct rbd_image_header *header = &rbd_dev->header;
983 984 985 986 987
	bool first_time = header->object_prefix == NULL;
	struct ceph_snap_context *snapc;
	char *object_prefix = NULL;
	char *snap_names = NULL;
	u64 *snap_sizes = NULL;
988
	u32 snap_count;
989
	int ret = -ENOMEM;
990
	u32 i;
991

992
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
993

994 995
	if (first_time) {
		size_t len;
996

997 998 999 1000 1001 1002 1003 1004
		len = strnlen(ondisk->object_prefix,
				sizeof (ondisk->object_prefix));
		object_prefix = kmalloc(len + 1, GFP_KERNEL);
		if (!object_prefix)
			return -ENOMEM;
		memcpy(object_prefix, ondisk->object_prefix, len);
		object_prefix[len] = '\0';
	}
A
Alex Elder 已提交
1005

1006
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
1007

1008 1009 1010 1011 1012
	snap_count = le32_to_cpu(ondisk->snap_count);
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
	if (!snapc)
		goto out_err;
	snapc->seq = le64_to_cpu(ondisk->snap_seq);
1013
	if (snap_count) {
1014
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
1015 1016
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

1017
		/* We'll keep a copy of the snapshot names... */
1018

1019 1020 1021 1022
		if (snap_names_len > (u64)SIZE_MAX)
			goto out_2big;
		snap_names = kmalloc(snap_names_len, GFP_KERNEL);
		if (!snap_names)
A
Alex Elder 已提交
1023 1024
			goto out_err;

1025
		/* ...as well as the array of their sizes. */
1026 1027 1028
		snap_sizes = kmalloc_array(snap_count,
					   sizeof(*header->snap_sizes),
					   GFP_KERNEL);
1029
		if (!snap_sizes)
A
Alex Elder 已提交
1030
			goto out_err;
1031

A
Alex Elder 已提交
1032
		/*
1033 1034 1035
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
1036
		 * Note that rbd_dev_v1_header_info() guarantees the
1037
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
1038 1039 1040
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
1041 1042 1043 1044 1045 1046
		memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
		snaps = ondisk->snaps;
		for (i = 0; i < snap_count; i++) {
			snapc->snaps[i] = le64_to_cpu(snaps[i].id);
			snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
		}
1047
	}
A
Alex Elder 已提交
1048

1049
	/* We won't fail any more, fill in the header */
1050

1051 1052 1053 1054 1055 1056 1057 1058 1059
	if (first_time) {
		header->object_prefix = object_prefix;
		header->obj_order = ondisk->options.order;
		header->crypt_type = ondisk->options.crypt_type;
		header->comp_type = ondisk->options.comp_type;
		/* The rest aren't used for format 1 images */
		header->stripe_unit = 0;
		header->stripe_count = 0;
		header->features = 0;
1060
	} else {
A
Alex Elder 已提交
1061 1062 1063
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
1064
	}
1065

1066
	/* The remaining fields always get updated (when we refresh) */
1067

A
Alex Elder 已提交
1068
	header->image_size = le64_to_cpu(ondisk->image_size);
1069 1070 1071
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1072

1073
	return 0;
1074 1075
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1076
out_err:
1077 1078 1079 1080
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1081

1082
	return ret;
1083 1084
}

1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
{
	const char *snap_name;

	rbd_assert(which < rbd_dev->header.snapc->num_snaps);

	/* Skip over names until we find the one we are looking for */

	snap_name = rbd_dev->header.snap_names;
	while (which--)
		snap_name += strlen(snap_name) + 1;

	return kstrdup(snap_name, GFP_KERNEL);
}

1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
/*
 * Snapshot id comparison function for use with qsort()/bsearch().
 * Note that result is for snapshots in *descending* order.
 */
static int snapid_compare_reverse(const void *s1, const void *s2)
{
	u64 snap_id1 = *(u64 *)s1;
	u64 snap_id2 = *(u64 *)s2;

	if (snap_id1 < snap_id2)
		return 1;
	return snap_id1 == snap_id2 ? 0 : -1;
}

/*
 * Search a snapshot context to see if the given snapshot id is
 * present.
 *
 * Returns the position of the snapshot id in the array if it's found,
 * or BAD_SNAP_INDEX otherwise.
 *
 * Note: The snapshot array is in kept sorted (by the osd) in
 * reverse order, highest snapshot id first.
 */
1124 1125 1126
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1127
	u64 *found;
1128

1129 1130
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1131

1132
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1133 1134
}

1135 1136
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1137
{
1138
	u32 which;
1139
	const char *snap_name;
1140

1141 1142
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1143
		return ERR_PTR(-ENOENT);
1144

1145 1146
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1147 1148 1149 1150
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1151 1152 1153
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1154 1155 1156
	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
	if (rbd_dev->image_format == 1)
		return rbd_dev_v1_snap_name(rbd_dev, snap_id);
1157

1158
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1159 1160
}

1161 1162
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1163
{
1164 1165 1166 1167 1168
	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
	if (snap_id == CEPH_NOSNAP) {
		*snap_size = rbd_dev->header.image_size;
	} else if (rbd_dev->image_format == 1) {
		u32 which;
1169

1170 1171 1172
		which = rbd_dev_snap_index(rbd_dev, snap_id);
		if (which == BAD_SNAP_INDEX)
			return -ENOENT;
1173

1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
		*snap_size = rbd_dev->header.snap_sizes[which];
	} else {
		u64 size = 0;
		int ret;

		ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
		if (ret)
			return ret;

		*snap_size = size;
	}
	return 0;
1186 1187
}

1188 1189
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1190
{
1191 1192 1193 1194 1195
	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
	if (snap_id == CEPH_NOSNAP) {
		*snap_features = rbd_dev->header.features;
	} else if (rbd_dev->image_format == 1) {
		*snap_features = 0;	/* No features for format 1 */
1196
	} else {
1197 1198
		u64 features = 0;
		int ret;
1199

1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
		ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
		if (ret)
			return ret;

		*snap_features = features;
	}
	return 0;
}

static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
{
1211
	u64 snap_id = rbd_dev->spec->snap_id;
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
	u64 size = 0;
	u64 features = 0;
	int ret;

	ret = rbd_snap_size(rbd_dev, snap_id, &size);
	if (ret)
		return ret;
	ret = rbd_snap_features(rbd_dev, snap_id, &features);
	if (ret)
		return ret;

	rbd_dev->mapping.size = size;
	rbd_dev->mapping.features = features;

1226
	return 0;
1227 1228
}

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static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
{
	rbd_dev->mapping.size = 0;
	rbd_dev->mapping.features = 0;
1233 1234
}

1235 1236 1237 1238 1239 1240 1241
static void rbd_segment_name_free(const char *name)
{
	/* The explicit cast here is needed to drop the const qualifier */

	kmem_cache_free(rbd_segment_name_cache, (void *)name);
}

A
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1242
static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1243
{
A
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1244 1245 1246
	char *name;
	u64 segment;
	int ret;
1247
	char *name_format;
1248

1249
	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
A
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1250 1251 1252
	if (!name)
		return NULL;
	segment = offset >> rbd_dev->header.obj_order;
1253 1254 1255
	name_format = "%s.%012llx";
	if (rbd_dev->image_format == 2)
		name_format = "%s.%016llx";
1256
	ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
A
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1257
			rbd_dev->header.object_prefix, segment);
1258
	if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
A
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1259 1260
		pr_err("error formatting segment name for #%llu (%d)\n",
			segment, ret);
1261
		rbd_segment_name_free(name);
A
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1262 1263
		name = NULL;
	}
1264

A
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1265 1266
	return name;
}
1267

A
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1268 1269 1270
static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1271

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1272 1273 1274 1275 1276 1277 1278 1279 1280 1281
	return offset & (segment_size - 1);
}

static u64 rbd_segment_length(struct rbd_device *rbd_dev,
				u64 offset, u64 length)
{
	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;

	offset &= segment_size - 1;

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	rbd_assert(length <= U64_MAX - offset);
A
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1283 1284 1285 1286
	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1287 1288
}

1289 1290 1291 1292 1293 1294 1295 1296
/*
 * returns the size of an object in the image
 */
static u64 rbd_obj_bytes(struct rbd_image_header *header)
{
	return 1 << header->obj_order;
}

1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316
/*
 * bio helpers
 */

static void bio_chain_put(struct bio *chain)
{
	struct bio *tmp;

	while (chain) {
		tmp = chain;
		chain = chain->bi_next;
		bio_put(tmp);
	}
}

/*
 * zeros a bio chain, starting at specific offset
 */
static void zero_bio_chain(struct bio *chain, int start_ofs)
{
1317 1318
	struct bio_vec bv;
	struct bvec_iter iter;
1319 1320 1321 1322 1323
	unsigned long flags;
	void *buf;
	int pos = 0;

	while (chain) {
1324 1325
		bio_for_each_segment(bv, chain, iter) {
			if (pos + bv.bv_len > start_ofs) {
1326
				int remainder = max(start_ofs - pos, 0);
1327
				buf = bvec_kmap_irq(&bv, &flags);
1328
				memset(buf + remainder, 0,
1329 1330
				       bv.bv_len - remainder);
				flush_dcache_page(bv.bv_page);
1331
				bvec_kunmap_irq(buf, &flags);
1332
			}
1333
			pos += bv.bv_len;
1334 1335 1336 1337 1338 1339
		}

		chain = chain->bi_next;
	}
}

A
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1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
/*
 * similar to zero_bio_chain(), zeros data defined by a page array,
 * starting at the given byte offset from the start of the array and
 * continuing up to the given end offset.  The pages array is
 * assumed to be big enough to hold all bytes up to the end.
 */
static void zero_pages(struct page **pages, u64 offset, u64 end)
{
	struct page **page = &pages[offset >> PAGE_SHIFT];

	rbd_assert(end > offset);
	rbd_assert(end - offset <= (u64)SIZE_MAX);
	while (offset < end) {
		size_t page_offset;
		size_t length;
		unsigned long flags;
		void *kaddr;

1358 1359
		page_offset = offset & ~PAGE_MASK;
		length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
A
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1360 1361 1362
		local_irq_save(flags);
		kaddr = kmap_atomic(*page);
		memset(kaddr + page_offset, 0, length);
1363
		flush_dcache_page(*page);
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1364 1365 1366 1367 1368 1369 1370 1371
		kunmap_atomic(kaddr);
		local_irq_restore(flags);

		offset += length;
		page++;
	}
}

1372
/*
A
Alex Elder 已提交
1373 1374
 * Clone a portion of a bio, starting at the given byte offset
 * and continuing for the number of bytes indicated.
1375
 */
A
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1376 1377 1378 1379
static struct bio *bio_clone_range(struct bio *bio_src,
					unsigned int offset,
					unsigned int len,
					gfp_t gfpmask)
1380
{
A
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1381 1382
	struct bio *bio;

K
Kent Overstreet 已提交
1383
	bio = bio_clone(bio_src, gfpmask);
A
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1384 1385
	if (!bio)
		return NULL;	/* ENOMEM */
1386

K
Kent Overstreet 已提交
1387
	bio_advance(bio, offset);
1388
	bio->bi_iter.bi_size = len;
A
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1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418

	return bio;
}

/*
 * Clone a portion of a bio chain, starting at the given byte offset
 * into the first bio in the source chain and continuing for the
 * number of bytes indicated.  The result is another bio chain of
 * exactly the given length, or a null pointer on error.
 *
 * The bio_src and offset parameters are both in-out.  On entry they
 * refer to the first source bio and the offset into that bio where
 * the start of data to be cloned is located.
 *
 * On return, bio_src is updated to refer to the bio in the source
 * chain that contains first un-cloned byte, and *offset will
 * contain the offset of that byte within that bio.
 */
static struct bio *bio_chain_clone_range(struct bio **bio_src,
					unsigned int *offset,
					unsigned int len,
					gfp_t gfpmask)
{
	struct bio *bi = *bio_src;
	unsigned int off = *offset;
	struct bio *chain = NULL;
	struct bio **end;

	/* Build up a chain of clone bios up to the limit */

1419
	if (!bi || off >= bi->bi_iter.bi_size || !len)
A
Alex Elder 已提交
1420
		return NULL;		/* Nothing to clone */
1421

A
Alex Elder 已提交
1422 1423 1424 1425 1426
	end = &chain;
	while (len) {
		unsigned int bi_size;
		struct bio *bio;

1427 1428
		if (!bi) {
			rbd_warn(NULL, "bio_chain exhausted with %u left", len);
A
Alex Elder 已提交
1429
			goto out_err;	/* EINVAL; ran out of bio's */
1430
		}
1431
		bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
A
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1432 1433 1434 1435 1436 1437
		bio = bio_clone_range(bi, off, bi_size, gfpmask);
		if (!bio)
			goto out_err;	/* ENOMEM */

		*end = bio;
		end = &bio->bi_next;
1438

A
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1439
		off += bi_size;
1440
		if (off == bi->bi_iter.bi_size) {
A
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1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451
			bi = bi->bi_next;
			off = 0;
		}
		len -= bi_size;
	}
	*bio_src = bi;
	*offset = off;

	return chain;
out_err:
	bio_chain_put(chain);
1452 1453 1454 1455

	return NULL;
}

1456 1457 1458 1459 1460
/*
 * The default/initial value for all object request flags is 0.  For
 * each flag, once its value is set to 1 it is never reset to 0
 * again.
 */
A
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1461
static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1462
{
A
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1463
	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1464 1465
		struct rbd_device *rbd_dev;

A
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1466
		rbd_dev = obj_request->img_request->rbd_dev;
1467
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1468 1469 1470 1471
			obj_request);
	}
}

A
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1472
static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1473 1474
{
	smp_mb();
A
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1475
	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1476 1477
}

A
Alex Elder 已提交
1478
static void obj_request_done_set(struct rbd_obj_request *obj_request)
1479
{
A
Alex Elder 已提交
1480 1481
	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1482

A
Alex Elder 已提交
1483 1484
		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1485
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1486 1487 1488 1489
			obj_request);
	}
}

A
Alex Elder 已提交
1490
static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1491 1492
{
	smp_mb();
A
Alex Elder 已提交
1493
	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1494 1495
}

1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526
/*
 * This sets the KNOWN flag after (possibly) setting the EXISTS
 * flag.  The latter is set based on the "exists" value provided.
 *
 * Note that for our purposes once an object exists it never goes
 * away again.  It's possible that the response from two existence
 * checks are separated by the creation of the target object, and
 * the first ("doesn't exist") response arrives *after* the second
 * ("does exist").  In that case we ignore the second one.
 */
static void obj_request_existence_set(struct rbd_obj_request *obj_request,
				bool exists)
{
	if (exists)
		set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
	set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
	smp_mb();
}

static bool obj_request_known_test(struct rbd_obj_request *obj_request)
{
	smp_mb();
	return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
}

static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
{
	smp_mb();
	return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
}

1527 1528 1529 1530 1531 1532 1533 1534
static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
{
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;

	return obj_request->img_offset <
	    round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
}

A
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1535 1536
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1537 1538
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1539 1540 1541 1542 1543 1544 1545
	kref_get(&obj_request->kref);
}

static void rbd_obj_request_destroy(struct kref *kref);
static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
{
	rbd_assert(obj_request != NULL);
A
Alex Elder 已提交
1546 1547
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1548 1549 1550
	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1551 1552 1553 1554 1555 1556 1557
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
	     atomic_read(&img_request->kref.refcount));
	kref_get(&img_request->kref);
}

1558 1559
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
A
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1560 1561 1562 1563
static void rbd_img_request_destroy(struct kref *kref);
static void rbd_img_request_put(struct rbd_img_request *img_request)
{
	rbd_assert(img_request != NULL);
A
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1564 1565
	dout("%s: img %p (was %d)\n", __func__, img_request,
		atomic_read(&img_request->kref.refcount));
1566 1567 1568 1569
	if (img_request_child_test(img_request))
		kref_put(&img_request->kref, rbd_parent_request_destroy);
	else
		kref_put(&img_request->kref, rbd_img_request_destroy);
A
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1570 1571 1572 1573 1574
}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1575 1576
	rbd_assert(obj_request->img_request == NULL);

1577
	/* Image request now owns object's original reference */
A
Alex Elder 已提交
1578
	obj_request->img_request = img_request;
1579
	obj_request->which = img_request->obj_request_count;
1580 1581
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
A
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1582
	rbd_assert(obj_request->which != BAD_WHICH);
1583 1584
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
A
Alex Elder 已提交
1585 1586
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
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1587 1588 1589 1590 1591 1592
}

static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
	rbd_assert(obj_request->which != BAD_WHICH);
1593

A
Alex Elder 已提交
1594 1595
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1596
	list_del(&obj_request->links);
1597 1598 1599 1600
	rbd_assert(img_request->obj_request_count > 0);
	img_request->obj_request_count--;
	rbd_assert(obj_request->which == img_request->obj_request_count);
	obj_request->which = BAD_WHICH;
1601
	rbd_assert(obj_request_img_data_test(obj_request));
A
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1602 1603
	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1604
	obj_request->callback = NULL;
A
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1605 1606 1607 1608 1609 1610
	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1611
	case OBJ_REQUEST_NODATA:
A
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1612
	case OBJ_REQUEST_BIO:
1613
	case OBJ_REQUEST_PAGES:
A
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1614 1615 1616 1617 1618 1619
		return true;
	default:
		return false;
	}
}

1620 1621
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

1622
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1623
{
1624 1625 1626
	struct ceph_osd_request *osd_req = obj_request->osd_req;

	dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
1627 1628 1629 1630
	if (obj_request_img_data_test(obj_request)) {
		WARN_ON(obj_request->callback != rbd_img_obj_callback);
		rbd_img_request_get(obj_request->img_request);
	}
1631
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
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1632 1633
}

1634 1635 1636 1637 1638 1639 1640 1641 1642
static void rbd_obj_request_end(struct rbd_obj_request *obj_request)
{
	dout("%s %p\n", __func__, obj_request);
	ceph_osdc_cancel_request(obj_request->osd_req);
}

/*
 * Wait for an object request to complete.  If interrupted, cancel the
 * underlying osd request.
1643 1644
 *
 * @timeout: in jiffies, 0 means "wait forever"
1645
 */
1646 1647
static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
				  unsigned long timeout)
1648
{
1649
	long ret;
1650 1651

	dout("%s %p\n", __func__, obj_request);
1652 1653 1654 1655 1656 1657
	ret = wait_for_completion_interruptible_timeout(
					&obj_request->completion,
					ceph_timeout_jiffies(timeout));
	if (ret <= 0) {
		if (ret == 0)
			ret = -ETIMEDOUT;
1658
		rbd_obj_request_end(obj_request);
1659 1660
	} else {
		ret = 0;
1661 1662
	}

1663 1664 1665 1666 1667 1668 1669 1670 1671
	dout("%s %p ret %d\n", __func__, obj_request, (int)ret);
	return ret;
}

static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
{
	return __rbd_obj_request_wait(obj_request, 0);
}

A
Alex Elder 已提交
1672 1673
static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1674

A
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1675
	dout("%s: img %p\n", __func__, img_request);
1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691

	/*
	 * If no error occurred, compute the aggregate transfer
	 * count for the image request.  We could instead use
	 * atomic64_cmpxchg() to update it as each object request
	 * completes; not clear which way is better off hand.
	 */
	if (!img_request->result) {
		struct rbd_obj_request *obj_request;
		u64 xferred = 0;

		for_each_obj_request(img_request, obj_request)
			xferred += obj_request->xferred;
		img_request->xferred = xferred;
	}

A
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1692 1693 1694 1695 1696 1697
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
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1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714
/*
 * The default/initial value for all image request flags is 0.  Each
 * is conditionally set to 1 at image request initialization time
 * and currently never change thereafter.
 */
static void img_request_write_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_WRITE, &img_request->flags);
	smp_mb();
}

static bool img_request_write_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
}

1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729
/*
 * Set the discard flag when the img_request is an discard request
 */
static void img_request_discard_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_DISCARD, &img_request->flags);
	smp_mb();
}

static bool img_request_discard_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_DISCARD, &img_request->flags) != 0;
}

1730 1731 1732 1733 1734 1735
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1736 1737 1738 1739 1740 1741
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1742 1743 1744 1745 1746 1747
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1748 1749 1750 1751 1752 1753
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1754 1755 1756 1757 1758 1759
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1760 1761 1762 1763 1764 1765
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776
static enum obj_operation_type
rbd_img_request_op_type(struct rbd_img_request *img_request)
{
	if (img_request_write_test(img_request))
		return OBJ_OP_WRITE;
	else if (img_request_discard_test(img_request))
		return OBJ_OP_DISCARD;
	else
		return OBJ_OP_READ;
}

1777 1778 1779
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1780 1781 1782
	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1783 1784
	dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
		obj_request, obj_request->img_request, obj_request->result,
A
Alex Elder 已提交
1785
		xferred, length);
1786
	/*
1787 1788 1789 1790 1791 1792
	 * ENOENT means a hole in the image.  We zero-fill the entire
	 * length of the request.  A short read also implies zero-fill
	 * to the end of the request.  An error requires the whole
	 * length of the request to be reported finished with an error
	 * to the block layer.  In each case we update the xferred
	 * count to indicate the whole request was satisfied.
1793
	 */
A
Alex Elder 已提交
1794
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1795
	if (obj_request->result == -ENOENT) {
A
Alex Elder 已提交
1796 1797 1798 1799
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1800
		obj_request->result = 0;
A
Alex Elder 已提交
1801 1802 1803 1804 1805
	} else if (xferred < length && !obj_request->result) {
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, xferred);
		else
			zero_pages(obj_request->pages, xferred, length);
1806
	}
1807
	obj_request->xferred = length;
1808 1809 1810
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1811 1812
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1813 1814
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
A
Alex Elder 已提交
1815 1816
	if (obj_request->callback)
		obj_request->callback(obj_request);
1817 1818
	else
		complete_all(&obj_request->completion);
A
Alex Elder 已提交
1819 1820
}

1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836
static void rbd_obj_request_error(struct rbd_obj_request *obj_request, int err)
{
	obj_request->result = err;
	obj_request->xferred = 0;
	/*
	 * kludge - mirror rbd_obj_request_submit() to match a put in
	 * rbd_img_obj_callback()
	 */
	if (obj_request_img_data_test(obj_request)) {
		WARN_ON(obj_request->callback != rbd_img_obj_callback);
		rbd_img_request_get(obj_request->img_request);
	}
	obj_request_done_set(obj_request);
	rbd_obj_request_complete(obj_request);
}

1837
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1838
{
A
Alex Elder 已提交
1839
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1840
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1841 1842 1843 1844 1845
	bool layered = false;

	if (obj_request_img_data_test(obj_request)) {
		img_request = obj_request->img_request;
		layered = img_request && img_request_layered_test(img_request);
A
Alex Elder 已提交
1846
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1847
	}
A
Alex Elder 已提交
1848 1849 1850 1851

	dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
		obj_request, img_request, obj_request->result,
		obj_request->xferred, obj_request->length);
A
Alex Elder 已提交
1852 1853
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1854 1855
		rbd_img_parent_read(obj_request);
	else if (img_request)
1856 1857 1858
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1859 1860
}

1861
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1862
{
1863 1864 1865
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1866 1867
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1868 1869
	 */
	obj_request->xferred = obj_request->length;
1870
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1871 1872
}

1873 1874 1875 1876 1877 1878 1879 1880 1881
static void rbd_osd_discard_callback(struct rbd_obj_request *obj_request)
{
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
	 * There is no such thing as a successful short discard.  Set
	 * it to our originally-requested length.
	 */
	obj_request->xferred = obj_request->length;
1882 1883 1884
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1885 1886 1887
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1888 1889 1890 1891
/*
 * For a simple stat call there's nothing to do.  We'll do more if
 * this is part of a write sequence for a layered image.
 */
1892
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1893
{
A
Alex Elder 已提交
1894
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1895 1896 1897
	obj_request_done_set(obj_request);
}

I
Ilya Dryomov 已提交
1898 1899 1900 1901 1902 1903 1904 1905 1906 1907
static void rbd_osd_call_callback(struct rbd_obj_request *obj_request)
{
	dout("%s: obj %p\n", __func__, obj_request);

	if (obj_request_img_data_test(obj_request))
		rbd_osd_copyup_callback(obj_request);
	else
		obj_request_done_set(obj_request);
}

1908
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
Alex Elder 已提交
1909 1910 1911 1912
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

1913
	dout("%s: osd_req %p\n", __func__, osd_req);
A
Alex Elder 已提交
1914
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1915 1916 1917 1918 1919 1920
	if (obj_request_img_data_test(obj_request)) {
		rbd_assert(obj_request->img_request);
		rbd_assert(obj_request->which != BAD_WHICH);
	} else {
		rbd_assert(obj_request->which == BAD_WHICH);
	}
A
Alex Elder 已提交
1921

1922 1923
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1924

1925 1926
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1927 1928
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1929
	 */
1930
	obj_request->xferred = osd_req->r_ops[0].outdata_len;
A
Alex Elder 已提交
1931
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1932

1933
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1934 1935
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1936
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1937
		break;
1938
	case CEPH_OSD_OP_SETALLOCHINT:
1939 1940
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
			   osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1941
		/* fall through */
A
Alex Elder 已提交
1942
	case CEPH_OSD_OP_WRITE:
1943
	case CEPH_OSD_OP_WRITEFULL:
1944
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1945
		break;
A
Alex Elder 已提交
1946
	case CEPH_OSD_OP_STAT:
1947
		rbd_osd_stat_callback(obj_request);
A
Alex Elder 已提交
1948
		break;
1949 1950 1951 1952 1953
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1954
	case CEPH_OSD_OP_CALL:
I
Ilya Dryomov 已提交
1955 1956
		rbd_osd_call_callback(obj_request);
		break;
A
Alex Elder 已提交
1957
	default:
1958
		rbd_warn(NULL, "%s: unsupported op %hu",
A
Alex Elder 已提交
1959 1960 1961 1962
			obj_request->object_name, (unsigned short) opcode);
		break;
	}

1963
	if (obj_request_done_test(obj_request))
A
Alex Elder 已提交
1964 1965 1966
		rbd_obj_request_complete(obj_request);
}

1967
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1968
{
1969
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1970

1971 1972
	rbd_assert(obj_request_img_data_test(obj_request));
	osd_req->r_snapid = obj_request->img_request->snap_id;
1973 1974 1975 1976 1977 1978
}

static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
{
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1979 1980
	osd_req->r_mtime = CURRENT_TIME;
	osd_req->r_data_offset = obj_request->offset;
A
Alex Elder 已提交
1981 1982
}

1983 1984 1985 1986 1987 1988
/*
 * Create an osd request.  A read request has one osd op (read).
 * A write request has either one (watch) or two (hint+write) osd ops.
 * (All rbd data writes are prefixed with an allocation hint op, but
 * technically osd watch is a write request, hence this distinction.)
 */
A
Alex Elder 已提交
1989 1990
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1991
					enum obj_operation_type op_type,
1992
					unsigned int num_ops,
A
Alex Elder 已提交
1993
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1994 1995 1996 1997 1998
{
	struct ceph_snap_context *snapc = NULL;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;

1999 2000
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
2001
		struct rbd_img_request *img_request = obj_request->img_request;
2002 2003 2004 2005 2006
		if (op_type == OBJ_OP_WRITE) {
			rbd_assert(img_request_write_test(img_request));
		} else {
			rbd_assert(img_request_discard_test(img_request));
		}
G
Guangliang Zhao 已提交
2007
		snapc = img_request->snapc;
A
Alex Elder 已提交
2008 2009
	}

G
Guangliang Zhao 已提交
2010
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
2011 2012

	/* Allocate and initialize the request, for the num_ops ops */
A
Alex Elder 已提交
2013 2014

	osdc = &rbd_dev->rbd_client->client->osdc;
2015
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
2016
					  GFP_NOIO);
A
Alex Elder 已提交
2017
	if (!osd_req)
2018
		goto fail;
A
Alex Elder 已提交
2019

2020
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
A
Alex Elder 已提交
2021
		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
A
Alex Elder 已提交
2022
	else
A
Alex Elder 已提交
2023 2024 2025 2026 2027
		osd_req->r_flags = CEPH_OSD_FLAG_READ;

	osd_req->r_callback = rbd_osd_req_callback;
	osd_req->r_priv = obj_request;

2028
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2029 2030 2031
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
A
Alex Elder 已提交
2032

2033 2034 2035
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

A
Alex Elder 已提交
2036
	return osd_req;
2037 2038 2039 2040

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
A
Alex Elder 已提交
2041 2042
}

2043
/*
2044 2045 2046 2047
 * Create a copyup osd request based on the information in the object
 * request supplied.  A copyup request has two or three osd ops, a
 * copyup method call, potentially a hint op, and a write or truncate
 * or zero op.
2048 2049 2050 2051 2052 2053 2054 2055 2056
 */
static struct ceph_osd_request *
rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	struct ceph_snap_context *snapc;
	struct rbd_device *rbd_dev;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;
2057
	int num_osd_ops = 3;
2058 2059 2060 2061

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
2062 2063
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
2064

2065 2066 2067 2068
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

	/* Allocate and initialize the request, for all the ops */
2069 2070 2071 2072

	snapc = img_request->snapc;
	rbd_dev = img_request->rbd_dev;
	osdc = &rbd_dev->rbd_client->client->osdc;
2073
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2074
						false, GFP_NOIO);
2075
	if (!osd_req)
2076
		goto fail;
2077 2078 2079 2080 2081

	osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
	osd_req->r_callback = rbd_osd_req_callback;
	osd_req->r_priv = obj_request;

2082
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2083 2084 2085
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
2086

2087 2088 2089
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

2090
	return osd_req;
2091 2092 2093 2094

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
2095 2096 2097
}


A
Alex Elder 已提交
2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

/* object_name is assumed to be a non-null pointer and NUL-terminated */

static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
						u64 offset, u64 length,
						enum obj_request_type type)
{
	struct rbd_obj_request *obj_request;
	size_t size;
	char *name;

	rbd_assert(obj_request_type_valid(type));

	size = strlen(object_name) + 1;
2116
	name = kmalloc(size, GFP_NOIO);
2117
	if (!name)
A
Alex Elder 已提交
2118 2119
		return NULL;

2120
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2121 2122 2123 2124 2125
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2126 2127 2128
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->offset = offset;
	obj_request->length = length;
2129
	obj_request->flags = 0;
A
Alex Elder 已提交
2130 2131 2132
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2133
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2134 2135
	kref_init(&obj_request->kref);

A
Alex Elder 已提交
2136 2137 2138
	dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
		offset, length, (int)type, obj_request);

A
Alex Elder 已提交
2139 2140 2141 2142 2143 2144 2145 2146 2147
	return obj_request;
}

static void rbd_obj_request_destroy(struct kref *kref)
{
	struct rbd_obj_request *obj_request;

	obj_request = container_of(kref, struct rbd_obj_request, kref);

A
Alex Elder 已提交
2148 2149
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2150 2151 2152 2153 2154 2155 2156 2157
	rbd_assert(obj_request->img_request == NULL);
	rbd_assert(obj_request->which == BAD_WHICH);

	if (obj_request->osd_req)
		rbd_osd_req_destroy(obj_request->osd_req);

	rbd_assert(obj_request_type_valid(obj_request->type));
	switch (obj_request->type) {
2158 2159
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2160 2161 2162 2163
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2164
	case OBJ_REQUEST_PAGES:
2165 2166 2167
		/* img_data requests don't own their page array */
		if (obj_request->pages &&
		    !obj_request_img_data_test(obj_request))
2168 2169 2170
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2171 2172
	}

2173
	kfree(obj_request->object_name);
2174 2175
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2176 2177
}

A
Alex Elder 已提交
2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188
/* It's OK to call this for a device with no parent */

static void rbd_spec_put(struct rbd_spec *spec);
static void rbd_dev_unparent(struct rbd_device *rbd_dev)
{
	rbd_dev_remove_parent(rbd_dev);
	rbd_spec_put(rbd_dev->parent_spec);
	rbd_dev->parent_spec = NULL;
	rbd_dev->parent_overlap = 0;
}

2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210
/*
 * Parent image reference counting is used to determine when an
 * image's parent fields can be safely torn down--after there are no
 * more in-flight requests to the parent image.  When the last
 * reference is dropped, cleaning them up is safe.
 */
static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
{
	int counter;

	if (!rbd_dev->parent_spec)
		return;

	counter = atomic_dec_return_safe(&rbd_dev->parent_ref);
	if (counter > 0)
		return;

	/* Last reference; clean up parent data structures */

	if (!counter)
		rbd_dev_unparent(rbd_dev);
	else
2211
		rbd_warn(rbd_dev, "parent reference underflow");
2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223
}

/*
 * If an image has a non-zero parent overlap, get a reference to its
 * parent.
 *
 * Returns true if the rbd device has a parent with a non-zero
 * overlap and a reference for it was successfully taken, or
 * false otherwise.
 */
static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
{
2224
	int counter = 0;
2225 2226 2227 2228

	if (!rbd_dev->parent_spec)
		return false;

2229 2230 2231 2232
	down_read(&rbd_dev->header_rwsem);
	if (rbd_dev->parent_overlap)
		counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
	up_read(&rbd_dev->header_rwsem);
2233 2234

	if (counter < 0)
2235
		rbd_warn(rbd_dev, "parent reference overflow");
2236

2237
	return counter > 0;
2238 2239
}

A
Alex Elder 已提交
2240 2241 2242 2243 2244
/*
 * Caller is responsible for filling in the list of object requests
 * that comprises the image request, and the Linux request pointer
 * (if there is one).
 */
A
Alex Elder 已提交
2245 2246
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2247
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2248
					enum obj_operation_type op_type,
2249
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2250 2251 2252
{
	struct rbd_img_request *img_request;

2253
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2254 2255 2256 2257 2258 2259 2260
	if (!img_request)
		return NULL;

	img_request->rq = NULL;
	img_request->rbd_dev = rbd_dev;
	img_request->offset = offset;
	img_request->length = length;
A
Alex Elder 已提交
2261
	img_request->flags = 0;
2262 2263 2264 2265
	if (op_type == OBJ_OP_DISCARD) {
		img_request_discard_set(img_request);
		img_request->snapc = snapc;
	} else if (op_type == OBJ_OP_WRITE) {
A
Alex Elder 已提交
2266
		img_request_write_set(img_request);
2267
		img_request->snapc = snapc;
A
Alex Elder 已提交
2268
	} else {
A
Alex Elder 已提交
2269
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2270
	}
2271
	if (rbd_dev_parent_get(rbd_dev))
2272
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2273 2274 2275
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2276
	img_request->result = 0;
A
Alex Elder 已提交
2277 2278 2279 2280
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2281
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2282
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2283

A
Alex Elder 已提交
2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294
	return img_request;
}

static void rbd_img_request_destroy(struct kref *kref)
{
	struct rbd_img_request *img_request;
	struct rbd_obj_request *obj_request;
	struct rbd_obj_request *next_obj_request;

	img_request = container_of(kref, struct rbd_img_request, kref);

A
Alex Elder 已提交
2295 2296
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2297 2298
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2299
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2300

2301 2302 2303 2304 2305
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2306 2307
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2308
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2309

2310
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2311 2312
}

2313 2314 2315 2316 2317 2318 2319 2320 2321 2322
static struct rbd_img_request *rbd_parent_request_create(
					struct rbd_obj_request *obj_request,
					u64 img_offset, u64 length)
{
	struct rbd_img_request *parent_request;
	struct rbd_device *rbd_dev;

	rbd_assert(obj_request->img_request);
	rbd_dev = obj_request->img_request->rbd_dev;

2323
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2324
						length, OBJ_OP_READ, NULL);
2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
	if (!parent_request)
		return NULL;

	img_request_child_set(parent_request);
	rbd_obj_request_get(obj_request);
	parent_request->obj_request = obj_request;

	return parent_request;
}

static void rbd_parent_request_destroy(struct kref *kref)
{
	struct rbd_img_request *parent_request;
	struct rbd_obj_request *orig_request;

	parent_request = container_of(kref, struct rbd_img_request, kref);
	orig_request = parent_request->obj_request;

	parent_request->obj_request = NULL;
	rbd_obj_request_put(orig_request);
	img_request_child_clear(parent_request);

	rbd_img_request_destroy(kref);
}

2350 2351
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2352
	struct rbd_img_request *img_request;
2353 2354
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2355
	bool more;
2356

2357 2358 2359
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2360 2361 2362 2363 2364
	rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
	xferred = (unsigned int)obj_request->xferred;
	result = obj_request->result;
	if (result) {
		struct rbd_device *rbd_dev = img_request->rbd_dev;
G
Guangliang Zhao 已提交
2365 2366
		enum obj_operation_type op_type;

2367 2368 2369 2370 2371 2372
		if (img_request_discard_test(img_request))
			op_type = OBJ_OP_DISCARD;
		else if (img_request_write_test(img_request))
			op_type = OBJ_OP_WRITE;
		else
			op_type = OBJ_OP_READ;
2373

2374
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2375 2376
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2377
		rbd_warn(rbd_dev, "  result %d xferred %x",
2378 2379 2380
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2381 2382 2383 2384 2385
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2386 2387
	}

A
Alex Elder 已提交
2388 2389 2390 2391 2392
	if (img_request_child_test(img_request)) {
		rbd_assert(img_request->obj_request != NULL);
		more = obj_request->which < img_request->obj_request_count - 1;
	} else {
		rbd_assert(img_request->rq != NULL);
C
Christoph Hellwig 已提交
2393 2394 2395 2396

		more = blk_update_request(img_request->rq, result, xferred);
		if (!more)
			__blk_mq_end_request(img_request->rq, result);
A
Alex Elder 已提交
2397 2398 2399
	}

	return more;
2400 2401
}

2402 2403 2404 2405 2406 2407
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	u32 which = obj_request->which;
	bool more = true;

2408
	rbd_assert(obj_request_img_data_test(obj_request));
2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426
	img_request = obj_request->img_request;

	dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
	rbd_assert(img_request != NULL);
	rbd_assert(img_request->obj_request_count > 0);
	rbd_assert(which != BAD_WHICH);
	rbd_assert(which < img_request->obj_request_count);

	spin_lock_irq(&img_request->completion_lock);
	if (which != img_request->next_completion)
		goto out;

	for_each_obj_request_from(img_request, obj_request) {
		rbd_assert(more);
		rbd_assert(which < img_request->obj_request_count);

		if (!obj_request_done_test(obj_request))
			break;
2427
		more = rbd_img_obj_end_request(obj_request);
2428 2429 2430 2431 2432 2433 2434
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2435
	rbd_img_request_put(img_request);
2436 2437 2438 2439 2440

	if (!more)
		rbd_img_request_complete(img_request);
}

2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459
/*
 * Add individual osd ops to the given ceph_osd_request and prepare
 * them for submission. num_ops is the current number of
 * osd operations already to the object request.
 */
static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
				struct ceph_osd_request *osd_request,
				enum obj_operation_type op_type,
				unsigned int num_ops)
{
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
	u64 object_size = rbd_obj_bytes(&rbd_dev->header);
	u64 offset = obj_request->offset;
	u64 length = obj_request->length;
	u64 img_end;
	u16 opcode;

	if (op_type == OBJ_OP_DISCARD) {
2460 2461 2462
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476
			opcode = CEPH_OSD_OP_DELETE;
		} else if ((offset + length == object_size)) {
			opcode = CEPH_OSD_OP_TRUNCATE;
		} else {
			down_read(&rbd_dev->header_rwsem);
			img_end = rbd_dev->header.image_size;
			up_read(&rbd_dev->header_rwsem);

			if (obj_request->img_offset + length == img_end)
				opcode = CEPH_OSD_OP_TRUNCATE;
			else
				opcode = CEPH_OSD_OP_ZERO;
		}
	} else if (op_type == OBJ_OP_WRITE) {
2477 2478 2479 2480
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2481 2482 2483 2484 2485 2486 2487
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2488
	if (opcode == CEPH_OSD_OP_DELETE)
2489
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2490 2491 2492 2493
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508
	if (obj_request->type == OBJ_REQUEST_BIO)
		osd_req_op_extent_osd_data_bio(osd_request, num_ops,
					obj_request->bio_list, length);
	else if (obj_request->type == OBJ_REQUEST_PAGES)
		osd_req_op_extent_osd_data_pages(osd_request, num_ops,
					obj_request->pages, length,
					offset & ~PAGE_MASK, false, false);

	/* Discards are also writes */
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
		rbd_osd_req_format_write(obj_request);
	else
		rbd_osd_req_format_read(obj_request);
}

2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519
/*
 * Split up an image request into one or more object requests, each
 * to a different object.  The "type" parameter indicates whether
 * "data_desc" is the pointer to the head of a list of bio
 * structures, or the base of a page array.  In either case this
 * function assumes data_desc describes memory sufficient to hold
 * all data described by the image request.
 */
static int rbd_img_request_fill(struct rbd_img_request *img_request,
					enum obj_request_type type,
					void *data_desc)
A
Alex Elder 已提交
2520 2521 2522 2523
{
	struct rbd_device *rbd_dev = img_request->rbd_dev;
	struct rbd_obj_request *obj_request = NULL;
	struct rbd_obj_request *next_obj_request;
J
Jingoo Han 已提交
2524
	struct bio *bio_list = NULL;
2525
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2526
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2527
	enum obj_operation_type op_type;
2528
	u64 img_offset;
A
Alex Elder 已提交
2529 2530
	u64 resid;

2531 2532
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2533

2534
	img_offset = img_request->offset;
A
Alex Elder 已提交
2535
	resid = img_request->length;
A
Alex Elder 已提交
2536
	rbd_assert(resid > 0);
2537
	op_type = rbd_img_request_op_type(img_request);
2538 2539 2540

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2541 2542
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2543
	} else if (type == OBJ_REQUEST_PAGES) {
2544 2545 2546
		pages = data_desc;
	}

A
Alex Elder 已提交
2547
	while (resid) {
2548
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2549 2550 2551 2552
		const char *object_name;
		u64 offset;
		u64 length;

2553
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2554 2555
		if (!object_name)
			goto out_unwind;
2556 2557
		offset = rbd_segment_offset(rbd_dev, img_offset);
		length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2558
		obj_request = rbd_obj_request_create(object_name,
2559
						offset, length, type);
2560 2561
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2562 2563
		if (!obj_request)
			goto out_unwind;
2564

2565 2566 2567 2568 2569
		/*
		 * set obj_request->img_request before creating the
		 * osd_request so that it gets the right snapc
		 */
		rbd_img_obj_request_add(img_request, obj_request);
A
Alex Elder 已提交
2570

2571 2572 2573 2574 2575 2576 2577 2578 2579
		if (type == OBJ_REQUEST_BIO) {
			unsigned int clone_size;

			rbd_assert(length <= (u64)UINT_MAX);
			clone_size = (unsigned int)length;
			obj_request->bio_list =
					bio_chain_clone_range(&bio_list,
								&bio_offset,
								clone_size,
2580
								GFP_NOIO);
2581
			if (!obj_request->bio_list)
2582
				goto out_unwind;
2583
		} else if (type == OBJ_REQUEST_PAGES) {
2584 2585 2586 2587 2588 2589 2590 2591 2592
			unsigned int page_count;

			obj_request->pages = pages;
			page_count = (u32)calc_pages_for(offset, length);
			obj_request->page_count = page_count;
			if ((offset + length) & ~PAGE_MASK)
				page_count--;	/* more on last page */
			pages += page_count;
		}
A
Alex Elder 已提交
2593

G
Guangliang Zhao 已提交
2594 2595 2596
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2597
		if (!osd_req)
2598
			goto out_unwind;
2599

2600
		obj_request->osd_req = osd_req;
2601
		obj_request->callback = rbd_img_obj_callback;
2602
		obj_request->img_offset = img_offset;
2603

2604
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2605

2606
		img_offset += length;
A
Alex Elder 已提交
2607 2608 2609 2610 2611 2612 2613
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2614
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2615 2616 2617 2618

	return -ENOMEM;
}

2619
static void
I
Ilya Dryomov 已提交
2620
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2621 2622 2623
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2624
	struct page **pages;
2625 2626
	u32 page_count;

I
Ilya Dryomov 已提交
2627 2628
	dout("%s: obj %p\n", __func__, obj_request);

2629 2630
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2631 2632 2633 2634 2635 2636 2637
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);

	rbd_dev = img_request->rbd_dev;
	rbd_assert(rbd_dev);

2638 2639
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2640
	obj_request->copyup_pages = NULL;
2641 2642 2643 2644
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2645 2646 2647 2648 2649 2650 2651 2652 2653 2654

	/*
	 * We want the transfer count to reflect the size of the
	 * original write request.  There is no such thing as a
	 * successful short write, so if the request was successful
	 * we can just set it to the originally-requested length.
	 */
	if (!obj_request->result)
		obj_request->xferred = obj_request->length;

I
Ilya Dryomov 已提交
2655
	obj_request_done_set(obj_request);
2656 2657
}

2658 2659 2660 2661
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2662 2663
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2664
	struct page **pages;
2665
	enum obj_operation_type op_type;
2666
	u32 page_count;
2667
	int img_result;
2668
	u64 parent_length;
2669 2670 2671 2672 2673 2674 2675 2676

	rbd_assert(img_request_child_test(img_request));

	/* First get what we need from the image request */

	pages = img_request->copyup_pages;
	rbd_assert(pages != NULL);
	img_request->copyup_pages = NULL;
2677 2678 2679
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2680 2681 2682

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2683
	rbd_assert(obj_request_type_valid(orig_request->type));
2684
	img_result = img_request->result;
2685
	parent_length = img_request->length;
2686
	rbd_assert(img_result || parent_length == img_request->xferred);
2687
	rbd_img_request_put(img_request);
2688

2689 2690
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2691 2692
	rbd_assert(rbd_dev);

2693 2694 2695 2696 2697 2698 2699
	/*
	 * If the overlap has become 0 (most likely because the
	 * image has been flattened) we need to free the pages
	 * and re-submit the original write request.
	 */
	if (!rbd_dev->parent_overlap) {
		ceph_release_page_vector(pages, page_count);
2700 2701
		rbd_obj_request_submit(orig_request);
		return;
2702
	}
2703

2704
	if (img_result)
2705 2706
		goto out_err;

2707 2708
	/*
	 * The original osd request is of no use to use any more.
2709
	 * We need a new one that can hold the three ops in a copyup
2710 2711 2712
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2713
	img_result = -ENOMEM;
2714 2715 2716
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2717
	rbd_osd_req_destroy(orig_request->osd_req);
2718 2719
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2720
	orig_request->copyup_page_count = page_count;
2721

2722
	/* Initialize the copyup op */
2723

2724
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2725
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2726
						false, false);
2727

2728
	/* Add the other op(s) */
2729

2730 2731
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2732 2733 2734

	/* All set, send it off. */

2735 2736
	rbd_obj_request_submit(orig_request);
	return;
2737 2738

out_err:
2739
	ceph_release_page_vector(pages, page_count);
2740
	rbd_obj_request_error(orig_request, img_result);
2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753
}

/*
 * Read from the parent image the range of data that covers the
 * entire target of the given object request.  This is used for
 * satisfying a layered image write request when the target of an
 * object request from the image request does not exist.
 *
 * A page array big enough to hold the returned data is allocated
 * and supplied to rbd_img_request_fill() as the "data descriptor."
 * When the read completes, this page array will be transferred to
 * the original object request for the copyup operation.
 *
2754 2755
 * If an error occurs, it is recorded as the result of the original
 * object request in rbd_img_obj_exists_callback().
2756 2757 2758
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
2759
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775
	struct rbd_img_request *parent_request = NULL;
	u64 img_offset;
	u64 length;
	struct page **pages = NULL;
	u32 page_count;
	int result;

	rbd_assert(rbd_dev->parent != NULL);

	/*
	 * Determine the byte range covered by the object in the
	 * child image to which the original request was to be sent.
	 */
	img_offset = obj_request->img_offset - obj_request->offset;
	length = (u64)1 << rbd_dev->header.obj_order;

A
Alex Elder 已提交
2776 2777 2778 2779 2780 2781 2782 2783 2784 2785
	/*
	 * There is no defined parent data beyond the parent
	 * overlap, so limit what we read at that boundary if
	 * necessary.
	 */
	if (img_offset + length > rbd_dev->parent_overlap) {
		rbd_assert(img_offset < rbd_dev->parent_overlap);
		length = rbd_dev->parent_overlap - img_offset;
	}

2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798
	/*
	 * Allocate a page array big enough to receive the data read
	 * from the parent.
	 */
	page_count = (u32)calc_pages_for(0, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages)) {
		result = PTR_ERR(pages);
		pages = NULL;
		goto out_err;
	}

	result = -ENOMEM;
2799 2800
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2801 2802 2803 2804 2805 2806
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
2807

2808
	parent_request->copyup_pages = pages;
2809
	parent_request->copyup_page_count = page_count;
2810
	parent_request->callback = rbd_img_obj_parent_read_full_callback;
2811

2812 2813 2814 2815 2816
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2817
	parent_request->copyup_page_count = 0;
2818 2819 2820 2821 2822 2823 2824 2825 2826 2827
	parent_request->obj_request = NULL;
	rbd_obj_request_put(obj_request);
out_err:
	if (pages)
		ceph_release_page_vector(pages, page_count);
	if (parent_request)
		rbd_img_request_put(parent_request);
	return result;
}

2828 2829 2830
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2831
	struct rbd_device *rbd_dev;
2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842
	int result;

	rbd_assert(!obj_request_img_data_test(obj_request));

	/*
	 * All we need from the object request is the original
	 * request and the result of the STAT op.  Grab those, then
	 * we're done with the request.
	 */
	orig_request = obj_request->obj_request;
	obj_request->obj_request = NULL;
2843
	rbd_obj_request_put(orig_request);
2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854
	rbd_assert(orig_request);
	rbd_assert(orig_request->img_request);

	result = obj_request->result;
	obj_request->result = 0;

	dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
		obj_request, orig_request, result,
		obj_request->xferred, obj_request->length);
	rbd_obj_request_put(obj_request);

2855 2856
	/*
	 * If the overlap has become 0 (most likely because the
2857 2858
	 * image has been flattened) we need to re-submit the
	 * original request.
2859 2860 2861
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2862 2863
		rbd_obj_request_submit(orig_request);
		return;
2864
	}
2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875

	/*
	 * Our only purpose here is to determine whether the object
	 * exists, and we don't want to treat the non-existence as
	 * an error.  If something else comes back, transfer the
	 * error to the original request and complete it now.
	 */
	if (!result) {
		obj_request_existence_set(orig_request, true);
	} else if (result == -ENOENT) {
		obj_request_existence_set(orig_request, false);
2876 2877
	} else {
		goto fail_orig_request;
2878 2879 2880 2881 2882 2883
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2884 2885 2886 2887 2888 2889 2890
	result = rbd_img_obj_request_submit(orig_request);
	if (result)
		goto fail_orig_request;

	return;

fail_orig_request:
2891
	rbd_obj_request_error(orig_request, result);
2892 2893 2894 2895
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
2896
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2897
	struct rbd_obj_request *stat_request;
2898
	struct page **pages;
2899 2900 2901 2902
	u32 page_count;
	size_t size;
	int ret;

2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914
	stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
					      OBJ_REQUEST_PAGES);
	if (!stat_request)
		return -ENOMEM;

	stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
						   stat_request);
	if (!stat_request->osd_req) {
		ret = -ENOMEM;
		goto fail_stat_request;
	}

2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925
	/*
	 * The response data for a STAT call consists of:
	 *     le64 length;
	 *     struct {
	 *         le32 tv_sec;
	 *         le32 tv_nsec;
	 *     } mtime;
	 */
	size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
	page_count = (u32)calc_pages_for(0, size);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2926 2927 2928 2929
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto fail_stat_request;
	}
2930

2931 2932 2933
	osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
				     false, false);
2934 2935 2936 2937 2938 2939 2940

	rbd_obj_request_get(obj_request);
	stat_request->obj_request = obj_request;
	stat_request->pages = pages;
	stat_request->page_count = page_count;
	stat_request->callback = rbd_img_obj_exists_callback;

2941 2942
	rbd_obj_request_submit(stat_request);
	return 0;
2943

2944 2945
fail_stat_request:
	rbd_obj_request_put(stat_request);
2946 2947 2948
	return ret;
}

2949
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2950
{
2951 2952
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
2953

2954
	/* Reads */
2955 2956
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2957 2958 2959 2960 2961 2962
		return true;

	/* Non-layered writes */
	if (!img_request_layered_test(img_request))
		return true;

2963
	/*
2964 2965
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2966
	 */
2967 2968
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2969

2970 2971 2972 2973 2974 2975 2976 2977
	/*
	 * Entire-object layered writes - we will overwrite whatever
	 * parent data there is anyway.
	 */
	if (!obj_request->offset &&
	    obj_request->length == rbd_obj_bytes(&rbd_dev->header))
		return true;

2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990
	/*
	 * If the object is known to already exist, its parent data has
	 * already been copied.
	 */
	if (obj_request_known_test(obj_request) &&
	    obj_request_exists_test(obj_request))
		return true;

	return false;
}

static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
{
2991 2992 2993
	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request_type_valid(obj_request->type));
	rbd_assert(obj_request->img_request);
2994

2995
	if (img_obj_request_simple(obj_request)) {
2996 2997
		rbd_obj_request_submit(obj_request);
		return 0;
2998 2999 3000
	}

	/*
3001 3002 3003 3004
	 * It's a layered write.  The target object might exist but
	 * we may not know that yet.  If we know it doesn't exist,
	 * start by reading the data for the full target object from
	 * the parent so we can use it for a copyup to the target.
3005
	 */
3006
	if (obj_request_known_test(obj_request))
3007 3008 3009
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
3010 3011 3012 3013

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
3014 3015 3016
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
3017
	struct rbd_obj_request *next_obj_request;
3018
	int ret = 0;
A
Alex Elder 已提交
3019

A
Alex Elder 已提交
3020
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
3021

3022 3023
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
3024
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
3025
		if (ret)
3026
			goto out_put_ireq;
A
Alex Elder 已提交
3027 3028
	}

3029 3030 3031
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
3032
}
A
Alex Elder 已提交
3033 3034 3035 3036

static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
A
Alex Elder 已提交
3037 3038
	struct rbd_device *rbd_dev;
	u64 obj_end;
3039 3040
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
3041 3042 3043

	rbd_assert(img_request_child_test(img_request));

3044 3045
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
3046
	obj_request = img_request->obj_request;
3047 3048 3049 3050 3051 3052 3053 3054 3055
	img_xferred = img_request->xferred;
	img_result = img_request->result;
	rbd_img_request_put(img_request);

	/*
	 * If the overlap has become 0 (most likely because the
	 * image has been flattened) we need to re-submit the
	 * original request.
	 */
A
Alex Elder 已提交
3056 3057
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
3058 3059
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
3060 3061
		rbd_obj_request_submit(obj_request);
		return;
3062
	}
A
Alex Elder 已提交
3063

3064
	obj_request->result = img_result;
A
Alex Elder 已提交
3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082
	if (obj_request->result)
		goto out;

	/*
	 * We need to zero anything beyond the parent overlap
	 * boundary.  Since rbd_img_obj_request_read_callback()
	 * will zero anything beyond the end of a short read, an
	 * easy way to do this is to pretend the data from the
	 * parent came up short--ending at the overlap boundary.
	 */
	rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
	obj_end = obj_request->img_offset + obj_request->length;
	if (obj_end > rbd_dev->parent_overlap) {
		u64 xferred = 0;

		if (obj_request->img_offset < rbd_dev->parent_overlap)
			xferred = rbd_dev->parent_overlap -
					obj_request->img_offset;
A
Alex Elder 已提交
3083

3084
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
3085
	} else {
3086
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
3087 3088
	}
out:
A
Alex Elder 已提交
3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100
	rbd_img_obj_request_read_callback(obj_request);
	rbd_obj_request_complete(obj_request);
}

static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	int result;

	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request->img_request != NULL);
	rbd_assert(obj_request->result == (s32) -ENOENT);
3101
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3102 3103

	/* rbd_read_finish(obj_request, obj_request->length); */
3104
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
3105
						obj_request->img_offset,
3106
						obj_request->length);
A
Alex Elder 已提交
3107 3108 3109 3110
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

3111 3112 3113 3114 3115 3116
	if (obj_request->type == OBJ_REQUEST_BIO)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
						obj_request->bio_list);
	else
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
						obj_request->pages);
A
Alex Elder 已提交
3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132
	if (result)
		goto out_err;

	img_request->callback = rbd_img_parent_read_callback;
	result = rbd_img_request_submit(img_request);
	if (result)
		goto out_err;

	return;
out_err:
	if (img_request)
		rbd_img_request_put(img_request);
	obj_request->result = result;
	obj_request->xferred = 0;
	obj_request_done_set(obj_request);
}
A
Alex Elder 已提交
3133

3134
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
3135

3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175
static bool rbd_cid_equal(const struct rbd_client_id *lhs,
			  const struct rbd_client_id *rhs)
{
	return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
}

static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
{
	struct rbd_client_id cid;

	mutex_lock(&rbd_dev->watch_mutex);
	cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
	cid.handle = rbd_dev->watch_cookie;
	mutex_unlock(&rbd_dev->watch_mutex);
	return cid;
}

/*
 * lock_rwsem must be held for write
 */
static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
			      const struct rbd_client_id *cid)
{
	dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
	     rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
	     cid->gid, cid->handle);
	rbd_dev->owner_cid = *cid; /* struct */
}

static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
{
	mutex_lock(&rbd_dev->watch_mutex);
	sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
	mutex_unlock(&rbd_dev->watch_mutex);
}

/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3176
{
3177
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3178 3179
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
	char cookie[32];
3180
	int ret;
A
Alex Elder 已提交
3181

3182
	WARN_ON(__rbd_is_lock_owner(rbd_dev));
3183

3184 3185 3186 3187
	format_lock_cookie(rbd_dev, cookie);
	ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
			    RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
			    RBD_LOCK_TAG, "", 0);
3188
	if (ret)
3189
		return ret;
A
Alex Elder 已提交
3190

3191 3192 3193 3194
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
	rbd_set_owner_cid(rbd_dev, &cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
	return 0;
A
Alex Elder 已提交
3195 3196
}

3197 3198 3199 3200
/*
 * lock_rwsem must be held for write
 */
static int rbd_unlock(struct rbd_device *rbd_dev)
3201
{
3202
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3203
	char cookie[32];
3204 3205
	int ret;

3206
	WARN_ON(!__rbd_is_lock_owner(rbd_dev));
3207

3208
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3209

3210 3211 3212 3213 3214 3215
	format_lock_cookie(rbd_dev, cookie);
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
			      RBD_LOCK_NAME, cookie);
	if (ret && ret != -ENOENT) {
		rbd_warn(rbd_dev, "cls_unlock failed: %d", ret);
		return ret;
3216 3217
	}

3218 3219 3220
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
	return 0;
3221 3222
}

3223 3224 3225 3226
static int __rbd_notify_op_lock(struct rbd_device *rbd_dev,
				enum rbd_notify_op notify_op,
				struct page ***preply_pages,
				size_t *preply_len)
3227 3228
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3229 3230 3231 3232
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
	int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN;
	char buf[buf_size];
	void *p = buf;
3233

3234
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3235

3236 3237 3238 3239 3240
	/* encode *LockPayload NotifyMessage (op + ClientId) */
	ceph_start_encoding(&p, 2, 1, buf_size - CEPH_ENCODING_START_BLK_LEN);
	ceph_encode_32(&p, notify_op);
	ceph_encode_64(&p, cid.gid);
	ceph_encode_64(&p, cid.handle);
3241

3242 3243 3244
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3245 3246
}

3247 3248
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
3249
{
3250 3251
	struct page **reply_pages;
	size_t reply_len;
3252

3253 3254 3255
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
3256

3257 3258 3259 3260
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
3261

3262
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3263 3264
}

3265
static void rbd_notify_released_lock(struct work_struct *work)
3266
{
3267 3268
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
3269

3270
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3271 3272
}

3273
static int rbd_request_lock(struct rbd_device *rbd_dev)
3274
{
3275 3276 3277
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
3278 3279
	int ret;

3280
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3281

3282 3283 3284 3285
	ret = __rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_REQUEST_LOCK,
				   &reply_pages, &reply_len);
	if (ret && ret != -ETIMEDOUT) {
		rbd_warn(rbd_dev, "failed to request lock: %d", ret);
3286
		goto out;
3287
	}
3288

3289 3290 3291 3292
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
3293

3294 3295 3296 3297
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
3298

3299 3300
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
3301

3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577
			ceph_decode_32_safe(&p, end, len, e_inval);
			if (!len)
				continue;

			if (lock_owner_responded) {
				rbd_warn(rbd_dev,
					 "duplicate lock owners detected");
				ret = -EIO;
				goto out;
			}

			lock_owner_responded = true;
			ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
						  &struct_v, &len);
			if (ret) {
				rbd_warn(rbd_dev,
					 "failed to decode ResponseMessage: %d",
					 ret);
				goto e_inval;
			}

			ret = ceph_decode_32(&p);
		}
	}

	if (!lock_owner_responded) {
		rbd_warn(rbd_dev, "no lock owners detected");
		ret = -ETIMEDOUT;
	}

out:
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
	return ret;

e_inval:
	ret = -EINVAL;
	goto out;
}

static void wake_requests(struct rbd_device *rbd_dev, bool wake_all)
{
	dout("%s rbd_dev %p wake_all %d\n", __func__, rbd_dev, wake_all);

	cancel_delayed_work(&rbd_dev->lock_dwork);
	if (wake_all)
		wake_up_all(&rbd_dev->lock_waitq);
	else
		wake_up(&rbd_dev->lock_waitq);
}

static int get_lock_owner_info(struct rbd_device *rbd_dev,
			       struct ceph_locker **lockers, u32 *num_lockers)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	u8 lock_type;
	char *lock_tag;
	int ret;

	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
				 &rbd_dev->header_oloc, RBD_LOCK_NAME,
				 &lock_type, &lock_tag, lockers, num_lockers);
	if (ret)
		return ret;

	if (*num_lockers == 0) {
		dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
		goto out;
	}

	if (strcmp(lock_tag, RBD_LOCK_TAG)) {
		rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
			 lock_tag);
		ret = -EBUSY;
		goto out;
	}

	if (lock_type == CEPH_CLS_LOCK_SHARED) {
		rbd_warn(rbd_dev, "shared lock type detected");
		ret = -EBUSY;
		goto out;
	}

	if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
		    strlen(RBD_LOCK_COOKIE_PREFIX))) {
		rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
			 (*lockers)[0].id.cookie);
		ret = -EBUSY;
		goto out;
	}

out:
	kfree(lock_tag);
	return ret;
}

static int find_watcher(struct rbd_device *rbd_dev,
			const struct ceph_locker *locker)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_watch_item *watchers;
	u32 num_watchers;
	u64 cookie;
	int i;
	int ret;

	ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
				      &rbd_dev->header_oloc, &watchers,
				      &num_watchers);
	if (ret)
		return ret;

	sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
	for (i = 0; i < num_watchers; i++) {
		if (!memcmp(&watchers[i].addr, &locker->info.addr,
			    sizeof(locker->info.addr)) &&
		    watchers[i].cookie == cookie) {
			struct rbd_client_id cid = {
				.gid = le64_to_cpu(watchers[i].name.num),
				.handle = cookie,
			};

			dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
			     rbd_dev, cid.gid, cid.handle);
			rbd_set_owner_cid(rbd_dev, &cid);
			ret = 1;
			goto out;
		}
	}

	dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
	ret = 0;
out:
	kfree(watchers);
	return ret;
}

/*
 * lock_rwsem must be held for write
 */
static int rbd_try_lock(struct rbd_device *rbd_dev)
{
	struct ceph_client *client = rbd_dev->rbd_client->client;
	struct ceph_locker *lockers;
	u32 num_lockers;
	int ret;

	for (;;) {
		ret = rbd_lock(rbd_dev);
		if (ret != -EBUSY)
			return ret;

		/* determine if the current lock holder is still alive */
		ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers);
		if (ret)
			return ret;

		if (num_lockers == 0)
			goto again;

		ret = find_watcher(rbd_dev, lockers);
		if (ret) {
			if (ret > 0)
				ret = 0; /* have to request lock */
			goto out;
		}

		rbd_warn(rbd_dev, "%s%llu seems dead, breaking lock",
			 ENTITY_NAME(lockers[0].id.name));

		ret = ceph_monc_blacklist_add(&client->monc,
					      &lockers[0].info.addr);
		if (ret) {
			rbd_warn(rbd_dev, "blacklist of %s%llu failed: %d",
				 ENTITY_NAME(lockers[0].id.name), ret);
			goto out;
		}

		ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
					  &rbd_dev->header_oloc, RBD_LOCK_NAME,
					  lockers[0].id.cookie,
					  &lockers[0].id.name);
		if (ret && ret != -ENOENT)
			goto out;

again:
		ceph_free_lockers(lockers, num_lockers);
	}

out:
	ceph_free_lockers(lockers, num_lockers);
	return ret;
}

/*
 * ret is set only if lock_state is RBD_LOCK_STATE_UNLOCKED
 */
static enum rbd_lock_state rbd_try_acquire_lock(struct rbd_device *rbd_dev,
						int *pret)
{
	enum rbd_lock_state lock_state;

	down_read(&rbd_dev->lock_rwsem);
	dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (__rbd_is_lock_owner(rbd_dev)) {
		lock_state = rbd_dev->lock_state;
		up_read(&rbd_dev->lock_rwsem);
		return lock_state;
	}

	up_read(&rbd_dev->lock_rwsem);
	down_write(&rbd_dev->lock_rwsem);
	dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (!__rbd_is_lock_owner(rbd_dev)) {
		*pret = rbd_try_lock(rbd_dev);
		if (*pret)
			rbd_warn(rbd_dev, "failed to acquire lock: %d", *pret);
	}

	lock_state = rbd_dev->lock_state;
	up_write(&rbd_dev->lock_rwsem);
	return lock_state;
}

static void rbd_acquire_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
					    struct rbd_device, lock_dwork);
	enum rbd_lock_state lock_state;
	int ret;

	dout("%s rbd_dev %p\n", __func__, rbd_dev);
again:
	lock_state = rbd_try_acquire_lock(rbd_dev, &ret);
	if (lock_state != RBD_LOCK_STATE_UNLOCKED || ret == -EBLACKLISTED) {
		if (lock_state == RBD_LOCK_STATE_LOCKED)
			wake_requests(rbd_dev, true);
		dout("%s rbd_dev %p lock_state %d ret %d - done\n", __func__,
		     rbd_dev, lock_state, ret);
		return;
	}

	ret = rbd_request_lock(rbd_dev);
	if (ret == -ETIMEDOUT) {
		goto again; /* treat this as a dead client */
	} else if (ret < 0) {
		rbd_warn(rbd_dev, "error requesting lock: %d", ret);
		mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
				 RBD_RETRY_DELAY);
	} else {
		/*
		 * lock owner acked, but resend if we don't see them
		 * release the lock
		 */
		dout("%s rbd_dev %p requeueing lock_dwork\n", __func__,
		     rbd_dev);
		mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
		    msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
	}
}

/*
 * lock_rwsem must be held for write
 */
static bool rbd_release_lock(struct rbd_device *rbd_dev)
{
	dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
		return false;

	rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
	downgrade_write(&rbd_dev->lock_rwsem);
3578
	/*
3579
	 * Ensure that all in-flight IO is flushed.
3580
	 *
3581 3582
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3583
	 */
3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730
	ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc);
	up_read(&rbd_dev->lock_rwsem);

	down_write(&rbd_dev->lock_rwsem);
	dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
		return false;

	if (!rbd_unlock(rbd_dev))
		/*
		 * Give others a chance to grab the lock - we would re-acquire
		 * almost immediately if we got new IO during ceph_osdc_sync()
		 * otherwise.  We need to ack our own notifications, so this
		 * lock_dwork will be requeued from rbd_wait_state_locked()
		 * after wake_requests() in rbd_handle_released_lock().
		 */
		cancel_delayed_work(&rbd_dev->lock_dwork);

	return true;
}

static void rbd_release_lock_work(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  unlock_work);

	down_write(&rbd_dev->lock_rwsem);
	rbd_release_lock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
}

static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
				     void **p)
{
	struct rbd_client_id cid = { 0 };

	if (struct_v >= 2) {
		cid.gid = ceph_decode_64(p);
		cid.handle = ceph_decode_64(p);
	}

	dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
	     cid.handle);
	if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
		down_write(&rbd_dev->lock_rwsem);
		if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
			/*
			 * we already know that the remote client is
			 * the owner
			 */
			up_write(&rbd_dev->lock_rwsem);
			return;
		}

		rbd_set_owner_cid(rbd_dev, &cid);
		downgrade_write(&rbd_dev->lock_rwsem);
	} else {
		down_read(&rbd_dev->lock_rwsem);
	}

	if (!__rbd_is_lock_owner(rbd_dev))
		wake_requests(rbd_dev, false);
	up_read(&rbd_dev->lock_rwsem);
}

static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
				     void **p)
{
	struct rbd_client_id cid = { 0 };

	if (struct_v >= 2) {
		cid.gid = ceph_decode_64(p);
		cid.handle = ceph_decode_64(p);
	}

	dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
	     cid.handle);
	if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
		down_write(&rbd_dev->lock_rwsem);
		if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
			dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n",
			     __func__, rbd_dev, cid.gid, cid.handle,
			     rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
			up_write(&rbd_dev->lock_rwsem);
			return;
		}

		rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
		downgrade_write(&rbd_dev->lock_rwsem);
	} else {
		down_read(&rbd_dev->lock_rwsem);
	}

	if (!__rbd_is_lock_owner(rbd_dev))
		wake_requests(rbd_dev, false);
	up_read(&rbd_dev->lock_rwsem);
}

static bool rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
				    void **p)
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
	bool need_to_send;

	if (struct_v >= 2) {
		cid.gid = ceph_decode_64(p);
		cid.handle = ceph_decode_64(p);
	}

	dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
	     cid.handle);
	if (rbd_cid_equal(&cid, &my_cid))
		return false;

	down_read(&rbd_dev->lock_rwsem);
	need_to_send = __rbd_is_lock_owner(rbd_dev);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
		if (!rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid)) {
			dout("%s rbd_dev %p queueing unlock_work\n", __func__,
			     rbd_dev);
			queue_work(rbd_dev->task_wq, &rbd_dev->unlock_work);
		}
	}
	up_read(&rbd_dev->lock_rwsem);
	return need_to_send;
}

static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
				     u64 notify_id, u64 cookie, s32 *result)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN;
	char buf[buf_size];
	int ret;

	if (result) {
		void *p = buf;

		/* encode ResponseMessage */
		ceph_start_encoding(&p, 1, 1,
				    buf_size - CEPH_ENCODING_START_BLK_LEN);
		ceph_encode_32(&p, *result);
	} else {
		buf_size = 0;
	}
A
Alex Elder 已提交
3731

3732 3733
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3734
				   buf, buf_size);
3735
	if (ret)
3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758
		rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
}

static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
				   u64 cookie)
{
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
	__rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
}

static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
					  u64 notify_id, u64 cookie, s32 result)
{
	dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
	__rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
}

static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
			 u64 notifier_id, void *data, size_t data_len)
{
	struct rbd_device *rbd_dev = arg;
	void *p = data;
	void *const end = p + data_len;
3759
	u8 struct_v = 0;
3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817
	u32 len;
	u32 notify_op;
	int ret;

	dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
	     __func__, rbd_dev, cookie, notify_id, data_len);
	if (data_len) {
		ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
					  &struct_v, &len);
		if (ret) {
			rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
				 ret);
			return;
		}

		notify_op = ceph_decode_32(&p);
	} else {
		/* legacy notification for header updates */
		notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
		len = 0;
	}

	dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
	switch (notify_op) {
	case RBD_NOTIFY_OP_ACQUIRED_LOCK:
		rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
		rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	case RBD_NOTIFY_OP_RELEASED_LOCK:
		rbd_handle_released_lock(rbd_dev, struct_v, &p);
		rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	case RBD_NOTIFY_OP_REQUEST_LOCK:
		if (rbd_handle_request_lock(rbd_dev, struct_v, &p))
			/*
			 * send ResponseMessage(0) back so the client
			 * can detect a missing owner
			 */
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
						      cookie, 0);
		else
			rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	case RBD_NOTIFY_OP_HEADER_UPDATE:
		ret = rbd_dev_refresh(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "refresh failed: %d", ret);

		rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	default:
		if (rbd_is_lock_owner(rbd_dev))
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
						      cookie, -EOPNOTSUPP);
		else
			rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	}
A
Alex Elder 已提交
3818 3819
}

3820 3821
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3822
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3823
{
3824
	struct rbd_device *rbd_dev = arg;
3825

3826
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3827

3828 3829 3830 3831
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3832 3833 3834 3835
	mutex_lock(&rbd_dev->watch_mutex);
	if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
		__rbd_unregister_watch(rbd_dev);
		rbd_dev->watch_state = RBD_WATCH_STATE_ERROR;
3836

3837
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3838
	}
3839
	mutex_unlock(&rbd_dev->watch_mutex);
3840 3841
}

3842
/*
3843
 * watch_mutex must be locked
3844
 */
3845
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3846 3847
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3848
	struct ceph_osd_linger_request *handle;
3849

3850
	rbd_assert(!rbd_dev->watch_handle);
3851
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3852

3853 3854 3855 3856 3857
	handle = ceph_osdc_watch(osdc, &rbd_dev->header_oid,
				 &rbd_dev->header_oloc, rbd_watch_cb,
				 rbd_watch_errcb, rbd_dev);
	if (IS_ERR(handle))
		return PTR_ERR(handle);
3858

3859
	rbd_dev->watch_handle = handle;
3860 3861 3862
	return 0;
}

3863 3864 3865 3866
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3867
{
3868 3869
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3870

3871 3872
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3873

3874 3875 3876
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3877

3878
	rbd_dev->watch_handle = NULL;
3879 3880
}

3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899
static int rbd_register_watch(struct rbd_device *rbd_dev)
{
	int ret;

	mutex_lock(&rbd_dev->watch_mutex);
	rbd_assert(rbd_dev->watch_state == RBD_WATCH_STATE_UNREGISTERED);
	ret = __rbd_register_watch(rbd_dev);
	if (ret)
		goto out;

	rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
	rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;

out:
	mutex_unlock(&rbd_dev->watch_mutex);
	return ret;
}

static void cancel_tasks_sync(struct rbd_device *rbd_dev)
3900
{
3901 3902 3903
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3904 3905 3906 3907
	cancel_work_sync(&rbd_dev->acquired_lock_work);
	cancel_work_sync(&rbd_dev->released_lock_work);
	cancel_delayed_work_sync(&rbd_dev->lock_dwork);
	cancel_work_sync(&rbd_dev->unlock_work);
3908 3909 3910 3911
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3912
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3913 3914 3915 3916 3917 3918 3919
	cancel_tasks_sync(rbd_dev);

	mutex_lock(&rbd_dev->watch_mutex);
	if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
		__rbd_unregister_watch(rbd_dev);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	mutex_unlock(&rbd_dev->watch_mutex);
I
Ilya Dryomov 已提交
3920 3921

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3922 3923
}

3924 3925 3926 3927
static void rbd_reregister_watch(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
					    struct rbd_device, watch_dwork);
3928
	bool was_lock_owner = false;
3929
	bool need_to_wake = false;
3930 3931 3932 3933
	int ret;

	dout("%s rbd_dev %p\n", __func__, rbd_dev);

3934 3935 3936 3937
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		was_lock_owner = rbd_release_lock(rbd_dev);

3938
	mutex_lock(&rbd_dev->watch_mutex);
3939 3940 3941 3942
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
	}
3943 3944 3945 3946

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3947
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3948 3949 3950
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
			need_to_wake = true;
		} else {
3951 3952 3953
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3954 3955 3956
		}
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
3957 3958
	}

3959
	need_to_wake = true;
3960 3961 3962 3963 3964 3965 3966 3967
	rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
	rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
	mutex_unlock(&rbd_dev->watch_mutex);

	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);

3968 3969 3970 3971 3972 3973 3974
	if (was_lock_owner) {
		ret = rbd_try_lock(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "reregisteration lock failed: %d",
				 ret);
	}

3975
out:
3976
	up_write(&rbd_dev->lock_rwsem);
3977 3978
	if (need_to_wake)
		wake_requests(rbd_dev, true);
3979 3980
}

3981
/*
3982 3983
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3984 3985 3986 3987 3988
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
			     const char *object_name,
			     const char *class_name,
			     const char *method_name,
3989
			     const void *outbound,
3990
			     size_t outbound_size,
3991
			     void *inbound,
3992
			     size_t inbound_size)
3993 3994 3995 3996 3997 3998 3999
{
	struct rbd_obj_request *obj_request;
	struct page **pages;
	u32 page_count;
	int ret;

	/*
4000 4001 4002 4003 4004
	 * Method calls are ultimately read operations.  The result
	 * should placed into the inbound buffer provided.  They
	 * also supply outbound data--parameters for the object
	 * method.  Currently if this is present it will be a
	 * snapshot id.
4005
	 */
4006
	page_count = (u32)calc_pages_for(0, inbound_size);
4007 4008 4009 4010 4011
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	ret = -ENOMEM;
4012
	obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
4013 4014 4015 4016 4017 4018 4019
							OBJ_REQUEST_PAGES);
	if (!obj_request)
		goto out;

	obj_request->pages = pages;
	obj_request->page_count = page_count;

G
Guangliang Zhao 已提交
4020
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4021
						  obj_request);
4022 4023 4024
	if (!obj_request->osd_req)
		goto out;

4025
	osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038
					class_name, method_name);
	if (outbound_size) {
		struct ceph_pagelist *pagelist;

		pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
		if (!pagelist)
			goto out;

		ceph_pagelist_init(pagelist);
		ceph_pagelist_append(pagelist, outbound, outbound_size);
		osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
						pagelist);
	}
4039 4040
	osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
					obj_request->pages, inbound_size,
4041
					0, false, false);
A
Alex Elder 已提交
4042

4043
	rbd_obj_request_submit(obj_request);
4044 4045 4046 4047 4048 4049 4050
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
4051 4052 4053

	rbd_assert(obj_request->xferred < (u64)INT_MAX);
	ret = (int)obj_request->xferred;
4054
	ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
4055 4056 4057 4058 4059 4060 4061 4062 4063
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082
/*
 * lock_rwsem must be held for read
 */
static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
{
	DEFINE_WAIT(wait);

	do {
		/*
		 * Note the use of mod_delayed_work() in rbd_acquire_lock()
		 * and cancel_delayed_work() in wake_requests().
		 */
		dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev);
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
		prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait,
					  TASK_UNINTERRUPTIBLE);
		up_read(&rbd_dev->lock_rwsem);
		schedule();
		down_read(&rbd_dev->lock_rwsem);
4083 4084 4085
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

4086 4087 4088
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
4089
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
4090
{
C
Christoph Hellwig 已提交
4091 4092
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
4093
	struct rbd_img_request *img_request;
4094
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
4095 4096
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
4097
	enum obj_operation_type op_type;
4098
	u64 mapping_size;
I
Ilya Dryomov 已提交
4099
	bool must_be_locked;
A
Alex Elder 已提交
4100 4101
	int result;

C
Christoph Hellwig 已提交
4102 4103 4104 4105 4106 4107 4108
	if (rq->cmd_type != REQ_TYPE_FS) {
		dout("%s: non-fs request type %d\n", __func__,
			(int) rq->cmd_type);
		result = -EIO;
		goto err;
	}

M
Mike Christie 已提交
4109
	if (req_op(rq) == REQ_OP_DISCARD)
4110
		op_type = OBJ_OP_DISCARD;
M
Mike Christie 已提交
4111
	else if (req_op(rq) == REQ_OP_WRITE)
G
Guangliang Zhao 已提交
4112 4113 4114 4115
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
4116
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4117

I
Ilya Dryomov 已提交
4118 4119 4120 4121 4122
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4123

G
Guangliang Zhao 已提交
4124
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
4125

G
Guangliang Zhao 已提交
4126
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
4127 4128 4129
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
4130
		}
I
Ilya Dryomov 已提交
4131 4132
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
4133

I
Ilya Dryomov 已提交
4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145
	/*
	 * Quit early if the mapped snapshot no longer exists.  It's
	 * still possible the snapshot will have disappeared by the
	 * time our request arrives at the osd, but there's no sense in
	 * sending it if we already know.
	 */
	if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
		dout("request for non-existent snapshot");
		rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
		result = -ENXIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4146

I
Ilya Dryomov 已提交
4147 4148 4149 4150 4151 4152
	if (offset && length > U64_MAX - offset + 1) {
		rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset,
			 length);
		result = -EINVAL;
		goto err_rq;	/* Shouldn't happen */
	}
A
Alex Elder 已提交
4153

C
Christoph Hellwig 已提交
4154 4155
	blk_mq_start_request(rq);

4156 4157
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4158
	if (op_type != OBJ_OP_READ) {
4159 4160
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
4161
		must_be_locked = rbd_is_lock_supported(rbd_dev);
I
Ilya Dryomov 已提交
4162 4163 4164
	} else {
		must_be_locked = rbd_dev->opts->lock_on_read &&
					rbd_is_lock_supported(rbd_dev);
4165 4166 4167 4168
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4169
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4170
			 length, mapping_size);
I
Ilya Dryomov 已提交
4171 4172 4173
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4174

4175 4176
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
4177 4178
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
4179
			rbd_wait_state_locked(rbd_dev);
4180 4181 4182 4183 4184 4185 4186

		WARN_ON((rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) ^
			!test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
4187 4188
	}

G
Guangliang Zhao 已提交
4189
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4190
					     snapc);
I
Ilya Dryomov 已提交
4191 4192
	if (!img_request) {
		result = -ENOMEM;
4193
		goto err_unlock;
I
Ilya Dryomov 已提交
4194 4195
	}
	img_request->rq = rq;
4196
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4197

4198 4199 4200 4201 4202 4203
	if (op_type == OBJ_OP_DISCARD)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
					      NULL);
	else
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
					      rq->bio);
I
Ilya Dryomov 已提交
4204 4205
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4206

I
Ilya Dryomov 已提交
4207 4208 4209
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4210

4211 4212
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4213
	return;
A
Alex Elder 已提交
4214

I
Ilya Dryomov 已提交
4215 4216
err_img_request:
	rbd_img_request_put(img_request);
4217 4218 4219
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4220 4221 4222
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4223
			 obj_op_name(op_type), length, offset, result);
4224
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4225 4226
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
4227
}
A
Alex Elder 已提交
4228

C
Christoph Hellwig 已提交
4229 4230
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4231
{
C
Christoph Hellwig 已提交
4232 4233
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4234

C
Christoph Hellwig 已提交
4235 4236
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
4237 4238
}

4239 4240 4241 4242 4243 4244 4245
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

4246 4247
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
4248
		del_gendisk(disk);
4249 4250
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
4251
		blk_mq_free_tag_set(&rbd_dev->tag_set);
4252
	}
4253 4254 4255
	put_disk(disk);
}

4256 4257
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
				const char *object_name,
4258
				u64 offset, u64 length, void *buf)
4259 4260 4261 4262 4263

{
	struct rbd_obj_request *obj_request;
	struct page **pages = NULL;
	u32 page_count;
4264
	size_t size;
4265 4266 4267 4268 4269
	int ret;

	page_count = (u32) calc_pages_for(offset, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
4270
		return PTR_ERR(pages);
4271 4272 4273

	ret = -ENOMEM;
	obj_request = rbd_obj_request_create(object_name, offset, length,
4274
							OBJ_REQUEST_PAGES);
4275 4276 4277 4278 4279 4280
	if (!obj_request)
		goto out;

	obj_request->pages = pages;
	obj_request->page_count = page_count;

G
Guangliang Zhao 已提交
4281
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4282
						  obj_request);
4283 4284 4285
	if (!obj_request->osd_req)
		goto out;

4286 4287
	osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
					offset, length, 0, 0);
4288
	osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
4289
					obj_request->pages,
4290 4291 4292
					obj_request->length,
					obj_request->offset & ~PAGE_MASK,
					false, false);
A
Alex Elder 已提交
4293

4294
	rbd_obj_request_submit(obj_request);
4295 4296 4297 4298 4299 4300 4301
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
4302 4303 4304

	rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
	size = (size_t) obj_request->xferred;
4305
	ceph_copy_from_page_vector(pages, buf, 0, size);
4306 4307
	rbd_assert(size <= (size_t)INT_MAX);
	ret = (int)size;
4308 4309 4310 4311 4312 4313 4314 4315 4316
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

4317
/*
A
Alex Elder 已提交
4318 4319 4320
 * Read the complete header for the given rbd device.  On successful
 * return, the rbd_dev->header field will contain up-to-date
 * information about the image.
4321
 */
4322
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4323
{
4324
	struct rbd_image_header_ondisk *ondisk = NULL;
4325
	u32 snap_count = 0;
4326 4327 4328
	u64 names_size = 0;
	u32 want_count;
	int ret;
4329

A
Alex Elder 已提交
4330
	/*
4331 4332 4333 4334 4335
	 * The complete header will include an array of its 64-bit
	 * snapshot ids, followed by the names of those snapshots as
	 * a contiguous block of NUL-terminated strings.  Note that
	 * the number of snapshots could change by the time we read
	 * it in, in which case we re-read it.
A
Alex Elder 已提交
4336
	 */
4337 4338 4339 4340 4341 4342 4343 4344 4345 4346
	do {
		size_t size;

		kfree(ondisk);

		size = sizeof (*ondisk);
		size += snap_count * sizeof (struct rbd_image_snap_ondisk);
		size += names_size;
		ondisk = kmalloc(size, GFP_KERNEL);
		if (!ondisk)
A
Alex Elder 已提交
4347
			return -ENOMEM;
4348

4349
		ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_oid.name,
4350
				       0, size, ondisk);
4351
		if (ret < 0)
A
Alex Elder 已提交
4352
			goto out;
A
Alex Elder 已提交
4353
		if ((size_t)ret < size) {
4354
			ret = -ENXIO;
A
Alex Elder 已提交
4355 4356
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4357
			goto out;
4358 4359 4360
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4361
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4362
			goto out;
4363
		}
4364

4365 4366 4367 4368
		names_size = le64_to_cpu(ondisk->snap_names_len);
		want_count = snap_count;
		snap_count = le32_to_cpu(ondisk->snap_count);
	} while (snap_count != want_count);
A
Alex Elder 已提交
4369

A
Alex Elder 已提交
4370 4371
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4372 4373 4374
	kfree(ondisk);

	return ret;
4375 4376
}

4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395
/*
 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
 * has disappeared from the (just updated) snapshot context.
 */
static void rbd_exists_validate(struct rbd_device *rbd_dev)
{
	u64 snap_id;

	if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
		return;

	snap_id = rbd_dev->spec->snap_id;
	if (snap_id == CEPH_NOSNAP)
		return;

	if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
		clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
}

4396 4397 4398 4399 4400
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4401 4402 4403
	 * If EXISTS is not set, rbd_dev->disk may be NULL, so don't
	 * try to update its size.  If REMOVING is set, updating size
	 * is just useless work since the device can't be opened.
4404
	 */
I
Ilya Dryomov 已提交
4405 4406
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4407 4408 4409 4410 4411 4412 4413
		size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
		dout("setting size to %llu sectors", (unsigned long long)size);
		set_capacity(rbd_dev->disk, size);
		revalidate_disk(rbd_dev->disk);
	}
}

A
Alex Elder 已提交
4414
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4415
{
4416
	u64 mapping_size;
A
Alex Elder 已提交
4417 4418
	int ret;

4419
	down_write(&rbd_dev->header_rwsem);
4420
	mapping_size = rbd_dev->mapping.size;
4421 4422

	ret = rbd_dev_header_info(rbd_dev);
4423
	if (ret)
4424
		goto out;
4425

4426 4427 4428 4429 4430 4431 4432
	/*
	 * If there is a parent, see if it has disappeared due to the
	 * mapped image getting flattened.
	 */
	if (rbd_dev->parent) {
		ret = rbd_dev_v2_parent_info(rbd_dev);
		if (ret)
4433
			goto out;
4434 4435
	}

4436
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4437
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4438 4439 4440 4441
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4442

4443
out:
4444
	up_write(&rbd_dev->header_rwsem);
4445
	if (!ret && mapping_size != rbd_dev->mapping.size)
4446
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4447

4448
	return ret;
A
Alex Elder 已提交
4449 4450
}

C
Christoph Hellwig 已提交
4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465
static int rbd_init_request(void *data, struct request *rq,
		unsigned int hctx_idx, unsigned int request_idx,
		unsigned int numa_node)
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

static struct blk_mq_ops rbd_mq_ops = {
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

4466 4467 4468 4469
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4470
	u64 segment_size;
C
Christoph Hellwig 已提交
4471
	int err;
4472 4473

	/* create gendisk info */
4474 4475 4476
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4477
	if (!disk)
A
Alex Elder 已提交
4478
		return -ENOMEM;
4479

A
Alex Elder 已提交
4480
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4481
		 rbd_dev->dev_id);
4482
	disk->major = rbd_dev->major;
4483
	disk->first_minor = rbd_dev->minor;
4484 4485
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4486 4487 4488
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4489 4490
	memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
	rbd_dev->tag_set.ops = &rbd_mq_ops;
I
Ilya Dryomov 已提交
4491
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4492
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4493
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4494 4495 4496 4497 4498
	rbd_dev->tag_set.nr_hw_queues = 1;
	rbd_dev->tag_set.cmd_size = sizeof(struct work_struct);

	err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
	if (err)
4499
		goto out_disk;
4500

C
Christoph Hellwig 已提交
4501 4502 4503 4504 4505 4506
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4507 4508
	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
	/* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
A
Alex Elder 已提交
4509

4510
	/* set io sizes to object size */
A
Alex Elder 已提交
4511 4512
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4513
	q->limits.max_sectors = queue_max_hw_sectors(q);
I
Ilya Dryomov 已提交
4514
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
4515 4516 4517
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4518

4519 4520 4521 4522
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
4523
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4524
	q->limits.discard_zeroes_data = 1;
4525

4526 4527 4528
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
		q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

4529 4530 4531 4532 4533 4534 4535
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4536 4537
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4538 4539
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4540
	return err;
4541 4542
}

4543 4544 4545 4546
/*
  sysfs
*/

A
Alex Elder 已提交
4547 4548 4549 4550 4551
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4552 4553 4554
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4555
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4556

A
Alex Elder 已提交
4557 4558
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4559 4560
}

A
Alex Elder 已提交
4561 4562 4563 4564 4565 4566 4567 4568 4569 4570
/*
 * Note this shows the features for whatever's mapped, which is not
 * necessarily the base image.
 */
static ssize_t rbd_features_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);

	return sprintf(buf, "0x%016llx\n",
A
Alex Elder 已提交
4571
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4572 4573
}

4574 4575 4576
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4577
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4578

A
Alex Elder 已提交
4579 4580 4581 4582
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4583 4584 4585 4586 4587 4588
}

static ssize_t rbd_minor_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
A
Alex Elder 已提交
4589

4590
	return sprintf(buf, "%d\n", rbd_dev->minor);
4591 4592
}

4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603
static ssize_t rbd_client_addr_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
	struct ceph_entity_addr *client_addr =
	    ceph_client_addr(rbd_dev->rbd_client->client);

	return sprintf(buf, "%pISpc/%u\n", &client_addr->in_addr,
		       le32_to_cpu(client_addr->nonce));
}

4604 4605
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4606
{
A
Alex Elder 已提交
4607
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4608

4609
	return sprintf(buf, "client%lld\n",
4610
		       ceph_client_gid(rbd_dev->rbd_client->client));
4611 4612
}

4613 4614 4615 4616 4617 4618 4619 4620
static ssize_t rbd_cluster_fsid_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);

	return sprintf(buf, "%pU\n", &rbd_dev->rbd_client->client->fsid);
}

4621 4622 4623 4624 4625 4626
static ssize_t rbd_config_info_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);

	return sprintf(buf, "%s\n", rbd_dev->config_info);
4627 4628
}

4629 4630
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4631
{
A
Alex Elder 已提交
4632
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4633

4634
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4635 4636
}

4637 4638 4639 4640 4641
static ssize_t rbd_pool_id_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);

4642
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4643
			(unsigned long long) rbd_dev->spec->pool_id);
4644 4645
}

4646 4647 4648
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4649
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4650

A
Alex Elder 已提交
4651 4652 4653 4654
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4655 4656
}

A
Alex Elder 已提交
4657 4658 4659 4660 4661
static ssize_t rbd_image_id_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);

4662
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4663 4664
}

A
Alex Elder 已提交
4665 4666 4667 4668
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4669 4670 4671 4672
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4673
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4674

4675
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4676 4677
}

4678 4679 4680 4681 4682 4683 4684 4685
static ssize_t rbd_snap_id_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);

	return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
}

4686
/*
4687 4688 4689
 * For a v2 image, shows the chain of parent images, separated by empty
 * lines.  For v1 images or if there is no parent, shows "(no parent
 * image)".
4690 4691
 */
static ssize_t rbd_parent_show(struct device *dev,
4692 4693
			       struct device_attribute *attr,
			       char *buf)
4694 4695
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4696
	ssize_t count = 0;
4697

4698
	if (!rbd_dev->parent)
4699 4700
		return sprintf(buf, "(no parent image)\n");

4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716
	for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
		struct rbd_spec *spec = rbd_dev->parent_spec;

		count += sprintf(&buf[count], "%s"
			    "pool_id %llu\npool_name %s\n"
			    "image_id %s\nimage_name %s\n"
			    "snap_id %llu\nsnap_name %s\n"
			    "overlap %llu\n",
			    !count ? "" : "\n", /* first? */
			    spec->pool_id, spec->pool_name,
			    spec->image_id, spec->image_name ?: "(unknown)",
			    spec->snap_id, spec->snap_name,
			    rbd_dev->parent_overlap);
	}

	return count;
4717 4718
}

4719 4720 4721 4722 4723
static ssize_t rbd_image_refresh(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf,
				 size_t size)
{
A
Alex Elder 已提交
4724
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4725
	int ret;
4726

A
Alex Elder 已提交
4727
	ret = rbd_dev_refresh(rbd_dev);
4728
	if (ret)
4729
		return ret;
4730

4731
	return size;
4732
}
4733

4734
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4735
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4736
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4737
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4738
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4739
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4740
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4741
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4742
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4743
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4744
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4745
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4746 4747
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4748
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4749
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4750 4751 4752

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4753
	&dev_attr_features.attr,
4754
	&dev_attr_major.attr,
4755
	&dev_attr_minor.attr,
4756
	&dev_attr_client_addr.attr,
4757
	&dev_attr_client_id.attr,
4758
	&dev_attr_cluster_fsid.attr,
4759
	&dev_attr_config_info.attr,
4760
	&dev_attr_pool.attr,
4761
	&dev_attr_pool_id.attr,
4762
	&dev_attr_name.attr,
A
Alex Elder 已提交
4763
	&dev_attr_image_id.attr,
4764
	&dev_attr_current_snap.attr,
4765
	&dev_attr_snap_id.attr,
4766
	&dev_attr_parent.attr,
4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779
	&dev_attr_refresh.attr,
	NULL
};

static struct attribute_group rbd_attr_group = {
	.attrs = rbd_attrs,
};

static const struct attribute_group *rbd_attr_groups[] = {
	&rbd_attr_group,
	NULL
};

4780
static void rbd_dev_release(struct device *dev);
4781 4782 4783 4784

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4785
	.release	= rbd_dev_release,
4786 4787
};

4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808
static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
{
	kref_get(&spec->kref);

	return spec;
}

static void rbd_spec_free(struct kref *kref);
static void rbd_spec_put(struct rbd_spec *spec)
{
	if (spec)
		kref_put(&spec->kref, rbd_spec_free);
}

static struct rbd_spec *rbd_spec_alloc(void)
{
	struct rbd_spec *spec;

	spec = kzalloc(sizeof (*spec), GFP_KERNEL);
	if (!spec)
		return NULL;
4809 4810 4811

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827
	kref_init(&spec->kref);

	return spec;
}

static void rbd_spec_free(struct kref *kref)
{
	struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);

	kfree(spec->pool_name);
	kfree(spec->image_id);
	kfree(spec->image_name);
	kfree(spec->snap_name);
	kfree(spec);
}

4828
static void rbd_dev_free(struct rbd_device *rbd_dev)
4829
{
4830
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4831
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4832

4833
	ceph_oid_destroy(&rbd_dev->header_oid);
4834
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4835
	kfree(rbd_dev->config_info);
4836

4837 4838 4839 4840
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853
}

static void rbd_dev_release(struct device *dev)
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
	bool need_put = !!rbd_dev->opts;

	if (need_put) {
		destroy_workqueue(rbd_dev->task_wq);
		ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
	}

	rbd_dev_free(rbd_dev);
4854 4855 4856 4857 4858 4859 4860 4861 4862 4863

	/*
	 * This is racy, but way better than putting module outside of
	 * the release callback.  The race window is pretty small, so
	 * doing something similar to dm (dm-builtin.c) is overkill.
	 */
	if (need_put)
		module_put(THIS_MODULE);
}

4864 4865
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4866 4867 4868
{
	struct rbd_device *rbd_dev;

4869
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4870 4871 4872 4873 4874 4875 4876
	if (!rbd_dev)
		return NULL;

	spin_lock_init(&rbd_dev->lock);
	INIT_LIST_HEAD(&rbd_dev->node);
	init_rwsem(&rbd_dev->header_rwsem);

4877
	ceph_oid_init(&rbd_dev->header_oid);
4878
	ceph_oloc_init(&rbd_dev->header_oloc);
4879

4880 4881 4882 4883
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4884 4885 4886 4887 4888 4889 4890 4891
	init_rwsem(&rbd_dev->lock_rwsem);
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
	INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
	INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
	INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
	INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
	init_waitqueue_head(&rbd_dev->lock_waitq);

4892 4893 4894 4895 4896
	rbd_dev->dev.bus = &rbd_bus_type;
	rbd_dev->dev.type = &rbd_device_type;
	rbd_dev->dev.parent = &rbd_root_dev;
	device_initialize(&rbd_dev->dev);

4897
	rbd_dev->rbd_client = rbdc;
4898
	rbd_dev->spec = spec;
4899

4900 4901 4902 4903
	rbd_dev->layout.stripe_unit = 1 << RBD_MAX_OBJ_ORDER;
	rbd_dev->layout.stripe_count = 1;
	rbd_dev->layout.object_size = 1 << RBD_MAX_OBJ_ORDER;
	rbd_dev->layout.pool_id = spec->pool_id;
4904
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
4905

4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935
	return rbd_dev;
}

/*
 * Create a mapping rbd_dev.
 */
static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
					 struct rbd_spec *spec,
					 struct rbd_options *opts)
{
	struct rbd_device *rbd_dev;

	rbd_dev = __rbd_dev_create(rbdc, spec);
	if (!rbd_dev)
		return NULL;

	rbd_dev->opts = opts;

	/* get an id and fill in device name */
	rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
					 minor_to_rbd_dev_id(1 << MINORBITS),
					 GFP_KERNEL);
	if (rbd_dev->dev_id < 0)
		goto fail_rbd_dev;

	sprintf(rbd_dev->name, RBD_DRV_NAME "%d", rbd_dev->dev_id);
	rbd_dev->task_wq = alloc_ordered_workqueue("%s-tasks", WQ_MEM_RECLAIM,
						   rbd_dev->name);
	if (!rbd_dev->task_wq)
		goto fail_dev_id;
4936

4937 4938
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4939

4940
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4941
	return rbd_dev;
4942 4943 4944 4945 4946 4947

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4948 4949 4950 4951
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4952 4953
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4954 4955
}

4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970
/*
 * Get the size and object order for an image snapshot, or if
 * snap_id is CEPH_NOSNAP, gets this information for the base
 * image.
 */
static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u8 *order, u64 *snap_size)
{
	__le64 snapid = cpu_to_le64(snap_id);
	int ret;
	struct {
		u8 order;
		__le64 size;
	} __attribute__ ((packed)) size_buf = { 0 };

4971
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4972
				"rbd", "get_size",
4973
				&snapid, sizeof (snapid),
4974
				&size_buf, sizeof (size_buf));
4975
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4976 4977
	if (ret < 0)
		return ret;
4978 4979
	if (ret < sizeof (size_buf))
		return -ERANGE;
4980

J
Josh Durgin 已提交
4981
	if (order) {
4982
		*order = size_buf.order;
J
Josh Durgin 已提交
4983 4984
		dout("  order %u", (unsigned int)*order);
	}
4985 4986
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4987 4988
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4989
		(unsigned long long)*snap_size);
4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 5000

	return 0;
}

static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
{
	return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
					&rbd_dev->header.obj_order,
					&rbd_dev->header.image_size);
}

5001 5002 5003 5004 5005 5006 5007 5008 5009 5010
static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
{
	void *reply_buf;
	int ret;
	void *p;

	reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
	if (!reply_buf)
		return -ENOMEM;

5011
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5012
				"rbd", "get_object_prefix", NULL, 0,
5013
				reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
5014
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5015 5016 5017 5018 5019
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5020 5021
						p + ret, NULL, GFP_NOIO);
	ret = 0;
5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034

	if (IS_ERR(rbd_dev->header.object_prefix)) {
		ret = PTR_ERR(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	} else {
		dout("  object_prefix = %s\n", rbd_dev->header.object_prefix);
	}
out:
	kfree(reply_buf);

	return ret;
}

5035 5036 5037 5038 5039 5040 5041
static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
		u64 *snap_features)
{
	__le64 snapid = cpu_to_le64(snap_id);
	struct {
		__le64 features;
		__le64 incompat;
5042
	} __attribute__ ((packed)) features_buf = { 0 };
5043
	u64 unsup;
5044 5045
	int ret;

5046
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5047
				"rbd", "get_features",
5048
				&snapid, sizeof (snapid),
5049
				&features_buf, sizeof (features_buf));
5050
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5051 5052
	if (ret < 0)
		return ret;
5053 5054
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
5055

5056 5057 5058 5059
	unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
	if (unsup) {
		rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
			 unsup);
A
Alex Elder 已提交
5060
		return -ENXIO;
5061
	}
A
Alex Elder 已提交
5062

5063 5064 5065
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5066 5067 5068
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
5069 5070 5071 5072 5073 5074 5075 5076 5077 5078

	return 0;
}

static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
{
	return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
						&rbd_dev->header.features);
}

5079 5080 5081 5082 5083 5084 5085 5086
static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
{
	struct rbd_spec *parent_spec;
	size_t size;
	void *reply_buf = NULL;
	__le64 snapid;
	void *p;
	void *end;
A
Alex Elder 已提交
5087
	u64 pool_id;
5088
	char *image_id;
5089
	u64 snap_id;
5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106
	u64 overlap;
	int ret;

	parent_spec = rbd_spec_alloc();
	if (!parent_spec)
		return -ENOMEM;

	size = sizeof (__le64) +				/* pool_id */
		sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX +	/* image_id */
		sizeof (__le64) +				/* snap_id */
		sizeof (__le64);				/* overlap */
	reply_buf = kmalloc(size, GFP_KERNEL);
	if (!reply_buf) {
		ret = -ENOMEM;
		goto out_err;
	}

5107
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5108
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5109
				"rbd", "get_parent",
5110
				&snapid, sizeof (snapid),
5111
				reply_buf, size);
5112
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5113 5114 5115 5116
	if (ret < 0)
		goto out_err;

	p = reply_buf;
5117 5118
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
5119
	ceph_decode_64_safe(&p, end, pool_id, out_err);
5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136
	if (pool_id == CEPH_NOPOOL) {
		/*
		 * Either the parent never existed, or we have
		 * record of it but the image got flattened so it no
		 * longer has a parent.  When the parent of a
		 * layered image disappears we immediately set the
		 * overlap to 0.  The effect of this is that all new
		 * requests will be treated as if the image had no
		 * parent.
		 */
		if (rbd_dev->parent_overlap) {
			rbd_dev->parent_overlap = 0;
			rbd_dev_parent_put(rbd_dev);
			pr_info("%s: clone image has been flattened\n",
				rbd_dev->disk->disk_name);
		}

5137
		goto out;	/* No parent?  No problem. */
5138
	}
5139

5140 5141 5142
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5143
	if (pool_id > (u64)U32_MAX) {
5144
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5145
			(unsigned long long)pool_id, U32_MAX);
5146
		goto out_err;
A
Alex Elder 已提交
5147
	}
5148

A
Alex Elder 已提交
5149
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5150 5151 5152 5153
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5154
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5155 5156
	ceph_decode_64_safe(&p, end, overlap, out_err);

5157 5158 5159 5160 5161 5162 5163 5164 5165
	/*
	 * The parent won't change (except when the clone is
	 * flattened, already handled that).  So we only need to
	 * record the parent spec we have not already done so.
	 */
	if (!rbd_dev->parent_spec) {
		parent_spec->pool_id = pool_id;
		parent_spec->image_id = image_id;
		parent_spec->snap_id = snap_id;
A
Alex Elder 已提交
5166 5167
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5168 5169
	} else {
		kfree(image_id);
5170 5171 5172
	}

	/*
5173 5174
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5175 5176 5177
	 */
	if (!overlap) {
		if (parent_spec) {
5178 5179 5180 5181
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5182
		} else {
5183 5184
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5185
		}
A
Alex Elder 已提交
5186
	}
5187 5188
	rbd_dev->parent_overlap = overlap;

5189 5190 5191 5192 5193 5194 5195 5196 5197
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210
static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
{
	struct {
		__le64 stripe_unit;
		__le64 stripe_count;
	} __attribute__ ((packed)) striping_info_buf = { 0 };
	size_t size = sizeof (striping_info_buf);
	void *p;
	u64 obj_size;
	u64 stripe_unit;
	u64 stripe_count;
	int ret;

5211
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5212
				"rbd", "get_stripe_unit_count", NULL, 0,
5213
				(char *)&striping_info_buf, size);
5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
	if (ret < 0)
		return ret;
	if (ret < size)
		return -ERANGE;

	/*
	 * We don't actually support the "fancy striping" feature
	 * (STRIPINGV2) yet, but if the striping sizes are the
	 * defaults the behavior is the same as before.  So find
	 * out, and only fail if the image has non-default values.
	 */
	ret = -EINVAL;
	obj_size = (u64)1 << rbd_dev->header.obj_order;
	p = &striping_info_buf;
	stripe_unit = ceph_decode_64(&p);
	if (stripe_unit != obj_size) {
		rbd_warn(rbd_dev, "unsupported stripe unit "
				"(got %llu want %llu)",
				stripe_unit, obj_size);
		return -EINVAL;
	}
	stripe_count = ceph_decode_64(&p);
	if (stripe_count != 1) {
		rbd_warn(rbd_dev, "unsupported stripe count "
				"(got %llu want 1)", stripe_count);
		return -EINVAL;
	}
5242 5243
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5244 5245 5246 5247

	return 0;
}

5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
	size_t image_id_size;
	char *image_id;
	void *p;
	void *end;
	size_t size;
	void *reply_buf = NULL;
	size_t len = 0;
	char *image_name = NULL;
	int ret;

	rbd_assert(!rbd_dev->spec->image_name);

A
Alex Elder 已提交
5262 5263
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5264 5265 5266 5267 5268
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5269
	end = image_id + image_id_size;
5270
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5271 5272 5273 5274 5275 5276

	size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
	reply_buf = kmalloc(size, GFP_KERNEL);
	if (!reply_buf)
		goto out;

5277
	ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
5278 5279
				"rbd", "dir_get_name",
				image_id, image_id_size,
5280
				reply_buf, size);
5281 5282 5283
	if (ret < 0)
		goto out;
	p = reply_buf;
5284 5285
	end = reply_buf + ret;

5286 5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297
	image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
	if (IS_ERR(image_name))
		image_name = NULL;
	else
		dout("%s: name is %s len is %zd\n", __func__, image_name, len);
out:
	kfree(reply_buf);
	kfree(image_id);

	return image_name;
}

5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322 5323 5324 5325 5326 5327
static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
	const char *snap_name;
	u32 which = 0;

	/* Skip over names until we find the one we are looking for */

	snap_name = rbd_dev->header.snap_names;
	while (which < snapc->num_snaps) {
		if (!strcmp(name, snap_name))
			return snapc->snaps[which];
		snap_name += strlen(snap_name) + 1;
		which++;
	}
	return CEPH_NOSNAP;
}

static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
	u32 which;
	bool found = false;
	u64 snap_id;

	for (which = 0; !found && which < snapc->num_snaps; which++) {
		const char *snap_name;

		snap_id = snapc->snaps[which];
		snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
5328 5329 5330 5331 5332 5333 5334
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352
		found = !strcmp(name, snap_name);
		kfree(snap_name);
	}
	return found ? snap_id : CEPH_NOSNAP;
}

/*
 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
 * no snapshot by that name is found, or if an error occurs.
 */
static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
{
	if (rbd_dev->image_format == 1)
		return rbd_v1_snap_id_by_name(rbd_dev, name);

	return rbd_v2_snap_id_by_name(rbd_dev, name);
}

5353
/*
5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380
 * An image being mapped will have everything but the snap id.
 */
static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;

	rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
	rbd_assert(spec->image_id && spec->image_name);
	rbd_assert(spec->snap_name);

	if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
		u64 snap_id;

		snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
		if (snap_id == CEPH_NOSNAP)
			return -ENOENT;

		spec->snap_id = snap_id;
	} else {
		spec->snap_id = CEPH_NOSNAP;
	}

	return 0;
}

/*
 * A parent image will have all ids but none of the names.
5381
 *
5382 5383
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5384
 */
5385
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5386
{
5387 5388 5389 5390 5391
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct rbd_spec *spec = rbd_dev->spec;
	const char *pool_name;
	const char *image_name;
	const char *snap_name;
5392 5393
	int ret;

5394 5395 5396
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5397

5398
	/* Get the pool name; we have to make our own copy of this */
5399

5400 5401 5402
	pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
	if (!pool_name) {
		rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
5403 5404
		return -EIO;
	}
5405 5406
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5407 5408 5409 5410
		return -ENOMEM;

	/* Fetch the image name; tolerate failure here */

5411 5412
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5413
		rbd_warn(rbd_dev, "unable to get image name");
5414

5415
	/* Fetch the snapshot name */
5416

5417
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5418 5419
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5420
		goto out_err;
5421 5422 5423 5424 5425
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5426 5427

	return 0;
5428

5429
out_err:
5430 5431
	kfree(image_name);
	kfree(pool_name);
5432 5433 5434
	return ret;
}

A
Alex Elder 已提交
5435
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458
{
	size_t size;
	int ret;
	void *reply_buf;
	void *p;
	void *end;
	u64 seq;
	u32 snap_count;
	struct ceph_snap_context *snapc;
	u32 i;

	/*
	 * We'll need room for the seq value (maximum snapshot id),
	 * snapshot count, and array of that many snapshot ids.
	 * For now we have a fixed upper limit on the number we're
	 * prepared to receive.
	 */
	size = sizeof (__le64) + sizeof (__le32) +
			RBD_MAX_SNAP_COUNT * sizeof (__le64);
	reply_buf = kzalloc(size, GFP_KERNEL);
	if (!reply_buf)
		return -ENOMEM;

5459
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5460
				"rbd", "get_snapcontext", NULL, 0,
5461
				reply_buf, size);
5462
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5463 5464 5465 5466
	if (ret < 0)
		goto out;

	p = reply_buf;
5467 5468
	end = reply_buf + ret;
	ret = -ERANGE;
5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484
	ceph_decode_64_safe(&p, end, seq, out);
	ceph_decode_32_safe(&p, end, snap_count, out);

	/*
	 * Make sure the reported number of snapshot ids wouldn't go
	 * beyond the end of our buffer.  But before checking that,
	 * make sure the computed size of the snapshot context we
	 * allocate is representable in a size_t.
	 */
	if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
				 / sizeof (u64)) {
		ret = -EINVAL;
		goto out;
	}
	if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
		goto out;
5485
	ret = 0;
5486

5487
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5488 5489 5490 5491 5492 5493 5494 5495
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5496
	ceph_put_snap_context(rbd_dev->header.snapc);
5497 5498 5499
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5500
		(unsigned long long)seq, (unsigned int)snap_count);
5501 5502 5503
out:
	kfree(reply_buf);

5504
	return ret;
5505 5506
}

5507 5508
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5509 5510 5511
{
	size_t size;
	void *reply_buf;
5512
	__le64 snapid;
A
Alex Elder 已提交
5513 5514 5515 5516 5517 5518 5519 5520 5521 5522
	int ret;
	void *p;
	void *end;
	char *snap_name;

	size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
	reply_buf = kmalloc(size, GFP_KERNEL);
	if (!reply_buf)
		return ERR_PTR(-ENOMEM);

5523
	snapid = cpu_to_le64(snap_id);
5524
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
A
Alex Elder 已提交
5525
				"rbd", "get_snapshot_name",
5526
				&snapid, sizeof (snapid),
5527
				reply_buf, size);
5528
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5529 5530
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5531
		goto out;
5532
	}
A
Alex Elder 已提交
5533 5534

	p = reply_buf;
5535
	end = reply_buf + ret;
A
Alex Elder 已提交
5536
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5537
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5538 5539
		goto out;

5540
	dout("  snap_id 0x%016llx snap_name = %s\n",
5541
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5542 5543 5544
out:
	kfree(reply_buf);

5545
	return snap_name;
A
Alex Elder 已提交
5546 5547
}

5548
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5549
{
5550
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5551 5552
	int ret;

5553 5554
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5555
		return ret;
5556

5557 5558 5559
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5560
			return ret;
5561 5562
	}

A
Alex Elder 已提交
5563
	ret = rbd_dev_v2_snap_context(rbd_dev);
5564 5565 5566 5567
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5568 5569 5570 5571

	return ret;
}

5572 5573 5574 5575 5576 5577 5578 5579 5580 5581
static int rbd_dev_header_info(struct rbd_device *rbd_dev)
{
	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));

	if (rbd_dev->image_format == 1)
		return rbd_dev_v1_header_info(rbd_dev);

	return rbd_dev_v2_header_info(rbd_dev);
}

5582 5583 5584
/*
 * Skips over white space at *buf, and updates *buf to point to the
 * first found non-space character (if any). Returns the length of
A
Alex Elder 已提交
5585 5586
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600
 */
static inline size_t next_token(const char **buf)
{
        /*
        * These are the characters that produce nonzero for
        * isspace() in the "C" and "POSIX" locales.
        */
        const char *spaces = " \f\n\r\t\v";

        *buf += strspn(*buf, spaces);	/* Find start of token */

	return strcspn(*buf, spaces);   /* Return token length */
}

A
Alex Elder 已提交
5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622
/*
 * Finds the next token in *buf, dynamically allocates a buffer big
 * enough to hold a copy of it, and copies the token into the new
 * buffer.  The copy is guaranteed to be terminated with '\0'.  Note
 * that a duplicate buffer is created even for a zero-length token.
 *
 * Returns a pointer to the newly-allocated duplicate, or a null
 * pointer if memory for the duplicate was not available.  If
 * the lenp argument is a non-null pointer, the length of the token
 * (not including the '\0') is returned in *lenp.
 *
 * If successful, the *buf pointer will be updated to point beyond
 * the end of the found token.
 *
 * Note: uses GFP_KERNEL for allocation.
 */
static inline char *dup_token(const char **buf, size_t *lenp)
{
	char *dup;
	size_t len;

	len = next_token(buf);
A
Alex Elder 已提交
5623
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5635
/*
5636 5637 5638 5639
 * Parse the options provided for an "rbd add" (i.e., rbd image
 * mapping) request.  These arrive via a write to /sys/bus/rbd/add,
 * and the data written is passed here via a NUL-terminated buffer.
 * Returns 0 if successful or an error code otherwise.
A
Alex Elder 已提交
5640
 *
5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672 5673 5674
 * The information extracted from these options is recorded in
 * the other parameters which return dynamically-allocated
 * structures:
 *  ceph_opts
 *      The address of a pointer that will refer to a ceph options
 *      structure.  Caller must release the returned pointer using
 *      ceph_destroy_options() when it is no longer needed.
 *  rbd_opts
 *	Address of an rbd options pointer.  Fully initialized by
 *	this function; caller must release with kfree().
 *  spec
 *	Address of an rbd image specification pointer.  Fully
 *	initialized by this function based on parsed options.
 *	Caller must release with rbd_spec_put().
 *
 * The options passed take this form:
 *  <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
 * where:
 *  <mon_addrs>
 *      A comma-separated list of one or more monitor addresses.
 *      A monitor address is an ip address, optionally followed
 *      by a port number (separated by a colon).
 *        I.e.:  ip1[:port1][,ip2[:port2]...]
 *  <options>
 *      A comma-separated list of ceph and/or rbd options.
 *  <pool_name>
 *      The name of the rados pool containing the rbd image.
 *  <image_name>
 *      The name of the image in that pool to map.
 *  <snap_id>
 *      An optional snapshot id.  If provided, the mapping will
 *      present data from the image at the time that snapshot was
 *      created.  The image head is used if no snapshot id is
 *      provided.  Snapshot mappings are always read-only.
5675
 */
5676
static int rbd_add_parse_args(const char *buf,
5677
				struct ceph_options **ceph_opts,
5678 5679
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5680
{
A
Alex Elder 已提交
5681
	size_t len;
5682
	char *options;
5683
	const char *mon_addrs;
5684
	char *snap_name;
5685
	size_t mon_addrs_size;
5686
	struct rbd_spec *spec = NULL;
5687
	struct rbd_options *rbd_opts = NULL;
5688
	struct ceph_options *copts;
5689
	int ret;
5690 5691 5692

	/* The first four tokens are required */

5693
	len = next_token(&buf);
5694 5695 5696 5697
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5698
	mon_addrs = buf;
5699
	mon_addrs_size = len + 1;
5700
	buf += len;
5701

5702
	ret = -EINVAL;
5703 5704
	options = dup_token(&buf, NULL);
	if (!options)
5705
		return -ENOMEM;
5706 5707 5708 5709
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5710

5711 5712
	spec = rbd_spec_alloc();
	if (!spec)
5713
		goto out_mem;
5714 5715 5716 5717

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5718 5719 5720 5721
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5722

A
Alex Elder 已提交
5723
	spec->image_name = dup_token(&buf, NULL);
5724
	if (!spec->image_name)
5725
		goto out_mem;
5726 5727 5728 5729
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5730

5731 5732 5733 5734
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5735
	len = next_token(&buf);
5736
	if (!len) {
5737 5738
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5739
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5740
		ret = -ENAMETOOLONG;
5741
		goto out_err;
5742
	}
5743 5744
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5745
		goto out_mem;
5746 5747
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5748

5749
	/* Initialize all rbd options to the defaults */
5750

5751 5752 5753 5754 5755
	rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
	if (!rbd_opts)
		goto out_mem;

	rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
I
Ilya Dryomov 已提交
5756
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5757
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
A
Alex Elder 已提交
5758

5759
	copts = ceph_parse_options(options, mon_addrs,
5760
					mon_addrs + mon_addrs_size - 1,
5761
					parse_rbd_opts_token, rbd_opts);
5762 5763
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5764 5765
		goto out_err;
	}
5766 5767 5768
	kfree(options);

	*ceph_opts = copts;
5769
	*opts = rbd_opts;
5770
	*rbd_spec = spec;
5771

5772
	return 0;
5773
out_mem:
5774
	ret = -ENOMEM;
A
Alex Elder 已提交
5775
out_err:
5776 5777
	kfree(rbd_opts);
	rbd_spec_put(spec);
5778
	kfree(options);
A
Alex Elder 已提交
5779

5780
	return ret;
5781 5782
}

5783 5784 5785 5786 5787
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5788
	struct ceph_options *opts = rbdc->client->options;
5789 5790 5791 5792 5793 5794 5795
	u64 newest_epoch;
	int tries = 0;
	int ret;

again:
	ret = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, pool_name);
	if (ret == -ENOENT && tries++ < 1) {
5796 5797
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5798 5799 5800 5801
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5802
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5803
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5804 5805
						     newest_epoch,
						     opts->mount_timeout);
5806 5807 5808 5809 5810 5811 5812 5813 5814 5815
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5816 5817 5818 5819 5820 5821 5822 5823 5824 5825 5826 5827 5828 5829 5830 5831 5832 5833 5834 5835
/*
 * An rbd format 2 image has a unique identifier, distinct from the
 * name given to it by the user.  Internally, that identifier is
 * what's used to specify the names of objects related to the image.
 *
 * A special "rbd id" object is used to map an rbd image name to its
 * id.  If that object doesn't exist, then there is no v2 rbd image
 * with the supplied name.
 *
 * This function will record the given rbd_dev's image_id field if
 * it can be determined, and in that case will return 0.  If any
 * errors occur a negative errno will be returned and the rbd_dev's
 * image_id field will be unchanged (and should be NULL).
 */
static int rbd_dev_image_id(struct rbd_device *rbd_dev)
{
	int ret;
	size_t size;
	char *object_name;
	void *response;
5836
	char *image_id;
5837

A
Alex Elder 已提交
5838 5839 5840
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5841 5842
	 * need to fetch the image id again in this case.  We
	 * do still need to set the image format though.
A
Alex Elder 已提交
5843
	 */
5844 5845 5846
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5847
		return 0;
5848
	}
A
Alex Elder 已提交
5849

A
Alex Elder 已提交
5850 5851 5852 5853
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
A
Alex Elder 已提交
5854
	size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
A
Alex Elder 已提交
5855 5856 5857
	object_name = kmalloc(size, GFP_NOIO);
	if (!object_name)
		return -ENOMEM;
5858
	sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
A
Alex Elder 已提交
5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869
	dout("rbd id object name is %s\n", object_name);

	/* Response will be an encoded string, which includes a length */

	size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
	response = kzalloc(size, GFP_NOIO);
	if (!response) {
		ret = -ENOMEM;
		goto out;
	}

5870 5871
	/* If it doesn't exist we'll assume it's a format 1 image */

5872
	ret = rbd_obj_method_sync(rbd_dev, object_name,
5873
				"rbd", "get_id", NULL, 0,
5874
				response, RBD_IMAGE_ID_LEN_MAX);
5875
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5876 5877 5878 5879 5880
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5881
	} else if (ret >= 0) {
5882 5883 5884
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5885
						NULL, GFP_NOIO);
5886
		ret = PTR_ERR_OR_ZERO(image_id);
5887 5888 5889 5890 5891 5892 5893
		if (!ret)
			rbd_dev->image_format = 2;
	}

	if (!ret) {
		rbd_dev->spec->image_id = image_id;
		dout("image_id is %s\n", image_id);
A
Alex Elder 已提交
5894 5895 5896 5897 5898 5899 5900 5901
	}
out:
	kfree(response);
	kfree(object_name);

	return ret;
}

A
Alex Elder 已提交
5902 5903 5904 5905
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5906 5907 5908 5909
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5910
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5911 5912 5913 5914

	/* Free dynamic fields from the header, then zero it out */

	header = &rbd_dev->header;
5915
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5916 5917 5918 5919 5920 5921
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5922
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5923 5924 5925
{
	int ret;

5926
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5927
	if (ret)
5928 5929
		goto out_err;

5930 5931 5932 5933
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5934
	ret = rbd_dev_v2_features(rbd_dev);
5935
	if (ret)
5936
		goto out_err;
5937

5938 5939 5940 5941 5942 5943 5944
	/* If the image supports fancy striping, get its parameters */

	if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
		ret = rbd_dev_v2_striping_info(rbd_dev);
		if (ret < 0)
			goto out_err;
	}
5945
	/* No support for crypto and compression type format 2 images */
5946

A
Alex Elder 已提交
5947
	return 0;
5948
out_err:
A
Alex Elder 已提交
5949
	rbd_dev->header.features = 0;
5950 5951
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5952 5953

	return ret;
5954 5955
}

5956 5957 5958 5959 5960 5961
/*
 * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
 * rbd_dev_image_probe() recursion depth, which means it's also the
 * length of the already discovered part of the parent chain.
 */
static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
A
Alex Elder 已提交
5962
{
5963
	struct rbd_device *parent = NULL;
5964 5965 5966 5967 5968
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5969 5970 5971 5972 5973 5974
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5975
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5976 5977
	if (!parent) {
		ret = -ENOMEM;
5978
		goto out_err;
5979 5980 5981 5982 5983 5984 5985 5986
	}

	/*
	 * Images related by parent/child relationships always share
	 * rbd_client and spec/parent_spec, so bump their refcounts.
	 */
	__rbd_get_client(rbd_dev->rbd_client);
	rbd_spec_get(rbd_dev->parent_spec);
5987

5988
	ret = rbd_dev_image_probe(parent, depth);
5989 5990
	if (ret < 0)
		goto out_err;
5991

5992
	rbd_dev->parent = parent;
5993
	atomic_set(&rbd_dev->parent_ref, 1);
5994
	return 0;
5995

5996
out_err:
5997
	rbd_dev_unparent(rbd_dev);
5998
	rbd_dev_destroy(parent);
5999 6000 6001
	return ret;
}

I
Ilya Dryomov 已提交
6002 6003 6004 6005
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
6006
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
6007
{
A
Alex Elder 已提交
6008
	int ret;
A
Alex Elder 已提交
6009

6010
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
6011

6012 6013 6014
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
6015
			goto err_out_unlock;
6016 6017 6018 6019 6020 6021 6022

		rbd_dev->major = ret;
		rbd_dev->minor = 0;
	} else {
		rbd_dev->major = rbd_major;
		rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
	}
A
Alex Elder 已提交
6023 6024 6025 6026 6027 6028 6029

	/* Set up the blkdev mapping. */

	ret = rbd_init_disk(rbd_dev);
	if (ret)
		goto err_out_blkdev;

6030
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
6031 6032
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
6033

6034
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6035
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
6036

6037 6038
	dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
	ret = device_add(&rbd_dev->dev);
6039
	if (ret)
6040
		goto err_out_mapping;
A
Alex Elder 已提交
6041 6042 6043

	/* Everything's ready.  Announce the disk to the world. */

6044
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
6045
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6046

6047 6048 6049 6050
	spin_lock(&rbd_dev_list_lock);
	list_add_tail(&rbd_dev->node, &rbd_dev_list);
	spin_unlock(&rbd_dev_list_lock);

I
Ilya Dryomov 已提交
6051
	add_disk(rbd_dev->disk);
6052 6053 6054
	pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
		(unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
		rbd_dev->header.features);
A
Alex Elder 已提交
6055 6056

	return ret;
6057

6058 6059
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
6060 6061 6062
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
6063 6064
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
6065 6066
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6067 6068 6069
	return ret;
}

A
Alex Elder 已提交
6070 6071 6072
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
6073
	int ret;
A
Alex Elder 已提交
6074 6075 6076 6077 6078

	/* Record the header object name for this rbd image. */

	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));

6079
	rbd_dev->header_oloc.pool = rbd_dev->layout.pool_id;
A
Alex Elder 已提交
6080
	if (rbd_dev->image_format == 1)
6081 6082
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
6083
	else
6084 6085
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
6086

6087
	return ret;
A
Alex Elder 已提交
6088 6089
}

6090 6091
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6092 6093 6094 6095 6096
	rbd_dev_unprobe(rbd_dev);
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

6097 6098 6099
	rbd_dev_destroy(rbd_dev);
}

6100 6101
/*
 * Probe for the existence of the header object for the given rbd
6102 6103 6104
 * device.  If this image is the one being mapped (i.e., not a
 * parent), initiate a watch on its header object before using that
 * object to get detailed information about the rbd image.
6105
 */
6106
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6107 6108 6109 6110
{
	int ret;

	/*
A
Alex Elder 已提交
6111 6112 6113 6114
	 * Get the id from the image id object.  Unless there's an
	 * error, rbd_dev->spec->image_id will be filled in with
	 * a dynamically-allocated string, and rbd_dev->image_format
	 * will be set to either 1 or 2.
6115 6116 6117
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6118 6119
		return ret;

A
Alex Elder 已提交
6120 6121 6122 6123
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6124
	if (!depth) {
6125
		ret = rbd_register_watch(rbd_dev);
6126 6127 6128 6129 6130
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6131
			goto err_out_format;
6132
		}
6133
	}
6134

6135
	ret = rbd_dev_header_info(rbd_dev);
6136
	if (ret)
6137
		goto err_out_watch;
A
Alex Elder 已提交
6138

6139 6140 6141 6142 6143 6144
	/*
	 * If this image is the one being mapped, we have pool name and
	 * id, image name and id, and snap name - need to fill snap id.
	 * Otherwise this is a parent image, identified by pool, image
	 * and snap ids - need to fill in names for those ids.
	 */
6145
	if (!depth)
6146 6147 6148
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6149 6150 6151 6152 6153 6154
	if (ret) {
		if (ret == -ENOENT)
			pr_info("snap %s/%s@%s does not exist\n",
				rbd_dev->spec->pool_name,
				rbd_dev->spec->image_name,
				rbd_dev->spec->snap_name);
A
Alex Elder 已提交
6155
		goto err_out_probe;
6156
	}
6157

6158 6159 6160 6161 6162 6163 6164 6165 6166
	if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
		ret = rbd_dev_v2_parent_info(rbd_dev);
		if (ret)
			goto err_out_probe;

		/*
		 * Need to warn users if this image is the one being
		 * mapped and has a parent.
		 */
6167
		if (!depth && rbd_dev->parent_spec)
6168 6169 6170 6171
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6172
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6173 6174 6175 6176
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6177
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6178
	return 0;
6179

A
Alex Elder 已提交
6180 6181
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6182
err_out_watch:
6183
	if (!depth)
6184
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6185 6186
err_out_format:
	rbd_dev->image_format = 0;
6187 6188
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6189 6190 6191
	return ret;
}

6192 6193 6194
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6195
{
6196
	struct rbd_device *rbd_dev = NULL;
6197
	struct ceph_options *ceph_opts = NULL;
6198
	struct rbd_options *rbd_opts = NULL;
6199
	struct rbd_spec *spec = NULL;
6200
	struct rbd_client *rbdc;
6201
	bool read_only;
6202
	int rc;
6203 6204 6205 6206 6207

	if (!try_module_get(THIS_MODULE))
		return -ENODEV;

	/* parse add command */
6208
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6209
	if (rc < 0)
6210
		goto out;
6211

6212 6213 6214
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6215
		goto err_out_args;
6216
	}
6217 6218

	/* pick the pool */
6219
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6220 6221 6222
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6223
		goto err_out_client;
6224
	}
A
Alex Elder 已提交
6225
	spec->pool_id = (u64)rc;
6226

6227
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6228 6229
	if (!rbd_dev) {
		rc = -ENOMEM;
6230
		goto err_out_client;
6231
	}
6232 6233
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6234
	rbd_opts = NULL;	/* rbd_dev now owns this */
6235

6236 6237 6238 6239 6240 6241
	rbd_dev->config_info = kstrdup(buf, GFP_KERNEL);
	if (!rbd_dev->config_info) {
		rc = -ENOMEM;
		goto err_out_rbd_dev;
	}

I
Ilya Dryomov 已提交
6242
	down_write(&rbd_dev->header_rwsem);
6243
	rc = rbd_dev_image_probe(rbd_dev, 0);
6244 6245
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6246
		goto err_out_rbd_dev;
6247
	}
6248

6249 6250
	/* If we are mapping a snapshot it must be marked read-only */

6251
	read_only = rbd_dev->opts->read_only;
6252 6253 6254 6255
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

6256
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
6257
	if (rc) {
6258
		/*
6259
		 * rbd_unregister_watch() can't be moved into
6260 6261 6262
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
6263
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6264
		rbd_dev_image_release(rbd_dev);
6265
		goto out;
A
Alex Elder 已提交
6266 6267
	}

6268 6269 6270 6271
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6272

6273 6274
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6275
err_out_client:
6276
	rbd_put_client(rbdc);
6277
err_out_args:
6278
	rbd_spec_put(spec);
6279
	kfree(rbd_opts);
6280
	goto out;
6281 6282
}

6283 6284 6285 6286 6287 6288 6289 6290 6291 6292 6293 6294 6295 6296 6297 6298 6299
static ssize_t rbd_add(struct bus_type *bus,
		       const char *buf,
		       size_t count)
{
	if (single_major)
		return -EINVAL;

	return do_rbd_add(bus, buf, count);
}

static ssize_t rbd_add_single_major(struct bus_type *bus,
				    const char *buf,
				    size_t count)
{
	return do_rbd_add(bus, buf, count);
}

6300
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6301 6302
{
	rbd_free_disk(rbd_dev);
6303 6304 6305 6306 6307

	spin_lock(&rbd_dev_list_lock);
	list_del_init(&rbd_dev->node);
	spin_unlock(&rbd_dev_list_lock);

6308
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6309
	device_del(&rbd_dev->dev);
A
Alex Elder 已提交
6310
	rbd_dev_mapping_clear(rbd_dev);
6311 6312
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
6313 6314
}

6315 6316
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6317
	while (rbd_dev->parent) {
6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329
		struct rbd_device *first = rbd_dev;
		struct rbd_device *second = first->parent;
		struct rbd_device *third;

		/*
		 * Follow to the parent with no grandparent and
		 * remove it.
		 */
		while (second && (third = second->parent)) {
			first = second;
			second = third;
		}
A
Alex Elder 已提交
6330
		rbd_assert(second);
6331
		rbd_dev_image_release(second);
A
Alex Elder 已提交
6332 6333 6334 6335
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6336 6337 6338 6339 6340
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6341 6342 6343
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6344 6345
{
	struct rbd_device *rbd_dev = NULL;
6346 6347
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6348
	char opt_buf[6];
6349
	bool already = false;
M
Mike Christie 已提交
6350
	bool force = false;
6351
	int ret;
6352

M
Mike Christie 已提交
6353 6354 6355 6356 6357
	dev_id = -1;
	opt_buf[0] = '\0';
	sscanf(buf, "%d %5s", &dev_id, opt_buf);
	if (dev_id < 0) {
		pr_err("dev_id out of range\n");
6358
		return -EINVAL;
M
Mike Christie 已提交
6359 6360 6361 6362 6363 6364 6365 6366 6367
	}
	if (opt_buf[0] != '\0') {
		if (!strcmp(opt_buf, "force")) {
			force = true;
		} else {
			pr_err("bad remove option at '%s'\n", opt_buf);
			return -EINVAL;
		}
	}
6368

6369 6370 6371 6372 6373 6374 6375 6376
	ret = -ENOENT;
	spin_lock(&rbd_dev_list_lock);
	list_for_each(tmp, &rbd_dev_list) {
		rbd_dev = list_entry(tmp, struct rbd_device, node);
		if (rbd_dev->dev_id == dev_id) {
			ret = 0;
			break;
		}
6377
	}
6378 6379
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6380
		if (rbd_dev->open_count && !force)
6381 6382
			ret = -EBUSY;
		else
6383 6384
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6385 6386 6387
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6388
	if (ret < 0 || already)
6389
		return ret;
6390

M
Mike Christie 已提交
6391 6392 6393 6394 6395 6396 6397 6398 6399
	if (force) {
		/*
		 * Prevent new IO from being queued and wait for existing
		 * IO to complete/fail.
		 */
		blk_mq_freeze_queue(rbd_dev->disk->queue);
		blk_set_queue_dying(rbd_dev->disk->queue);
	}

6400 6401 6402 6403
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
6404
	rbd_unregister_watch(rbd_dev);
6405

6406 6407 6408 6409 6410 6411
	/*
	 * Don't free anything from rbd_dev->disk until after all
	 * notifies are completely processed. Otherwise
	 * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
	 * in a potential use after free of rbd_dev->disk or rbd_dev.
	 */
6412
	rbd_dev_device_release(rbd_dev);
6413
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
6414

6415
	return count;
6416 6417
}

6418 6419 6420 6421 6422 6423 6424 6425 6426 6427 6428 6429 6430 6431 6432 6433 6434
static ssize_t rbd_remove(struct bus_type *bus,
			  const char *buf,
			  size_t count)
{
	if (single_major)
		return -EINVAL;

	return do_rbd_remove(bus, buf, count);
}

static ssize_t rbd_remove_single_major(struct bus_type *bus,
				       const char *buf,
				       size_t count)
{
	return do_rbd_remove(bus, buf, count);
}

6435 6436
/*
 * create control files in sysfs
6437
 * /sys/bus/rbd/...
6438 6439 6440
 */
static int rbd_sysfs_init(void)
{
6441
	int ret;
6442

6443
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6444
	if (ret < 0)
6445
		return ret;
6446

6447 6448 6449
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6450 6451 6452 6453 6454 6455

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6456
	bus_unregister(&rbd_bus_type);
6457
	device_unregister(&rbd_root_dev);
6458 6459
}

6460 6461 6462
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6463
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6464 6465 6466 6467
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6468
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6469 6470 6471 6472 6473
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6474
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6475
	if (rbd_segment_name_cache)
6476
		return 0;
6477
out_err:
6478 6479
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6480

6481 6482 6483
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

6484 6485 6486 6487 6488
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6489 6490 6491 6492
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

6493 6494 6495 6496
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6497 6498 6499 6500 6501
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
6502
static int __init rbd_init(void)
6503 6504 6505
{
	int rc;

6506 6507 6508 6509
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6510

6511
	rc = rbd_slab_init();
6512 6513
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6514

6515 6516
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6517
	 * rbd devices * queue depth, so leave @max_active at default.
6518 6519 6520 6521 6522 6523 6524
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6525 6526 6527 6528
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6529
			goto err_out_wq;
6530 6531 6532
		}
	}

6533 6534
	rc = rbd_sysfs_init();
	if (rc)
6535 6536 6537 6538 6539 6540
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6541

I
Ilya Dryomov 已提交
6542 6543
	return 0;

6544 6545 6546
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6547 6548
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6549 6550
err_out_slab:
	rbd_slab_exit();
6551
	return rc;
6552 6553
}

A
Alex Elder 已提交
6554
static void __exit rbd_exit(void)
6555
{
I
Ilya Dryomov 已提交
6556
	ida_destroy(&rbd_dev_id_ida);
6557
	rbd_sysfs_cleanup();
6558 6559
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6560
	destroy_workqueue(rbd_wq);
6561
	rbd_slab_exit();
6562 6563 6564 6565 6566
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6567
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6568 6569 6570 6571 6572
MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
/* following authorship retained from original osdblk.c */
MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");

6573
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6574
MODULE_LICENSE("GPL");