rbd.c 166.6 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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/*
 * Flag bits for rbd_dev->flags.  If atomicity is required,
 * rbd_dev->lock is used to protect access.
 *
 * Currently, only the "removing" flag (which is coupled with the
 * "open_count" field) requires atomic access.
 */
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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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};

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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);
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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
Guangliang Zhao 已提交
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
Alex Elder 已提交
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
Alex Elder 已提交
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
	size_t size;
990
	int ret = -ENOMEM;
991
	u32 i;
992

993
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
994

995 996
	if (first_time) {
		size_t len;
997

998 999 1000 1001 1002 1003 1004 1005
		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
1006

1007
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
1008

1009 1010 1011 1012 1013
	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);
1014
	if (snap_count) {
1015
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
1016 1017
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

1018
		/* We'll keep a copy of the snapshot names... */
1019

1020 1021 1022 1023
		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
1024 1025
			goto out_err;

1026
		/* ...as well as the array of their sizes. */
1027

1028
		size = snap_count * sizeof (*header->snap_sizes);
1029 1030
		snap_sizes = kmalloc(size, GFP_KERNEL);
		if (!snap_sizes)
A
Alex Elder 已提交
1031
			goto out_err;
1032

A
Alex Elder 已提交
1033
		/*
1034 1035 1036
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
1037
		 * Note that rbd_dev_v1_header_info() guarantees the
1038
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
1039 1040 1041
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
1042 1043 1044 1045 1046 1047
		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);
		}
1048
	}
A
Alex Elder 已提交
1049

1050
	/* We won't fail any more, fill in the header */
1051

1052 1053 1054 1055 1056 1057 1058 1059 1060
	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;
1061
	} else {
A
Alex Elder 已提交
1062 1063 1064
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
1065
	}
1066

1067
	/* The remaining fields always get updated (when we refresh) */
1068

A
Alex Elder 已提交
1069
	header->image_size = le64_to_cpu(ondisk->image_size);
1070 1071 1072
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1073

1074
	return 0;
1075 1076
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1077
out_err:
1078 1079 1080 1081
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1082

1083
	return ret;
1084 1085
}

1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100
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);
}

1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
/*
 * 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.
 */
1125 1126 1127
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1128
	u64 *found;
1129

1130 1131
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1132

1133
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1134 1135
}

1136 1137
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1138
{
1139
	u32 which;
1140
	const char *snap_name;
1141

1142 1143
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1144
		return ERR_PTR(-ENOENT);
1145

1146 1147
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1148 1149 1150 1151
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1152 1153 1154
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1155 1156 1157
	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);
1158

1159
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1160 1161
}

1162 1163
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1164
{
1165 1166 1167 1168 1169
	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;
1170

1171 1172 1173
		which = rbd_dev_snap_index(rbd_dev, snap_id);
		if (which == BAD_SNAP_INDEX)
			return -ENOENT;
1174

1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186
		*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;
1187 1188
}

1189 1190
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1191
{
1192 1193 1194 1195 1196
	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 */
1197
	} else {
1198 1199
		u64 features = 0;
		int ret;
1200

1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211
		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)
{
1212
	u64 snap_id = rbd_dev->spec->snap_id;
1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226
	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;

1227
	return 0;
1228 1229
}

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1230 1231 1232 1233
static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
{
	rbd_dev->mapping.size = 0;
	rbd_dev->mapping.features = 0;
1234 1235
}

1236 1237 1238 1239 1240 1241 1242
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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1243
static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1244
{
A
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1245 1246 1247
	char *name;
	u64 segment;
	int ret;
1248
	char *name_format;
1249

1250
	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
A
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1251 1252 1253
	if (!name)
		return NULL;
	segment = offset >> rbd_dev->header.obj_order;
1254 1255 1256
	name_format = "%s.%012llx";
	if (rbd_dev->image_format == 2)
		name_format = "%s.%016llx";
1257
	ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
A
Alex Elder 已提交
1258
			rbd_dev->header.object_prefix, segment);
1259
	if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
A
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1260 1261
		pr_err("error formatting segment name for #%llu (%d)\n",
			segment, ret);
1262
		rbd_segment_name_free(name);
A
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1263 1264
		name = NULL;
	}
1265

A
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1266 1267
	return name;
}
1268

A
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1269 1270 1271
static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1272

A
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1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
	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;

A
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1283
	rbd_assert(length <= U64_MAX - offset);
A
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1284 1285 1286 1287
	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1288 1289
}

1290 1291 1292 1293 1294 1295 1296 1297
/*
 * returns the size of an object in the image
 */
static u64 rbd_obj_bytes(struct rbd_image_header *header)
{
	return 1 << header->obj_order;
}

1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317
/*
 * 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)
{
1318 1319
	struct bio_vec bv;
	struct bvec_iter iter;
1320 1321 1322 1323 1324
	unsigned long flags;
	void *buf;
	int pos = 0;

	while (chain) {
1325 1326
		bio_for_each_segment(bv, chain, iter) {
			if (pos + bv.bv_len > start_ofs) {
1327
				int remainder = max(start_ofs - pos, 0);
1328
				buf = bvec_kmap_irq(&bv, &flags);
1329
				memset(buf + remainder, 0,
1330 1331
				       bv.bv_len - remainder);
				flush_dcache_page(bv.bv_page);
1332
				bvec_kunmap_irq(buf, &flags);
1333
			}
1334
			pos += bv.bv_len;
1335 1336 1337 1338 1339 1340
		}

		chain = chain->bi_next;
	}
}

A
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1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358
/*
 * 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;

1359 1360
		page_offset = offset & ~PAGE_MASK;
		length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
A
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1361 1362 1363
		local_irq_save(flags);
		kaddr = kmap_atomic(*page);
		memset(kaddr + page_offset, 0, length);
1364
		flush_dcache_page(*page);
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1365 1366 1367 1368 1369 1370 1371 1372
		kunmap_atomic(kaddr);
		local_irq_restore(flags);

		offset += length;
		page++;
	}
}

1373
/*
A
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1374 1375
 * Clone a portion of a bio, starting at the given byte offset
 * and continuing for the number of bytes indicated.
1376
 */
A
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1377 1378 1379 1380
static struct bio *bio_clone_range(struct bio *bio_src,
					unsigned int offset,
					unsigned int len,
					gfp_t gfpmask)
1381
{
A
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1382 1383
	struct bio *bio;

K
Kent Overstreet 已提交
1384
	bio = bio_clone(bio_src, gfpmask);
A
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1385 1386
	if (!bio)
		return NULL;	/* ENOMEM */
1387

K
Kent Overstreet 已提交
1388
	bio_advance(bio, offset);
1389
	bio->bi_iter.bi_size = len;
A
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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 1419

	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 */

1420
	if (!bi || off >= bi->bi_iter.bi_size || !len)
A
Alex Elder 已提交
1421
		return NULL;		/* Nothing to clone */
1422

A
Alex Elder 已提交
1423 1424 1425 1426 1427
	end = &chain;
	while (len) {
		unsigned int bi_size;
		struct bio *bio;

1428 1429
		if (!bi) {
			rbd_warn(NULL, "bio_chain exhausted with %u left", len);
A
Alex Elder 已提交
1430
			goto out_err;	/* EINVAL; ran out of bio's */
1431
		}
1432
		bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
A
Alex Elder 已提交
1433 1434 1435 1436 1437 1438
		bio = bio_clone_range(bi, off, bi_size, gfpmask);
		if (!bio)
			goto out_err;	/* ENOMEM */

		*end = bio;
		end = &bio->bi_next;
1439

A
Alex Elder 已提交
1440
		off += bi_size;
1441
		if (off == bi->bi_iter.bi_size) {
A
Alex Elder 已提交
1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
			bi = bi->bi_next;
			off = 0;
		}
		len -= bi_size;
	}
	*bio_src = bi;
	*offset = off;

	return chain;
out_err:
	bio_chain_put(chain);
1453 1454 1455 1456

	return NULL;
}

1457 1458 1459 1460 1461
/*
 * 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
Alex Elder 已提交
1462
static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1463
{
A
Alex Elder 已提交
1464
	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1465 1466
		struct rbd_device *rbd_dev;

A
Alex Elder 已提交
1467
		rbd_dev = obj_request->img_request->rbd_dev;
1468
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1469 1470 1471 1472
			obj_request);
	}
}

A
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1473
static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1474 1475
{
	smp_mb();
A
Alex Elder 已提交
1476
	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1477 1478
}

A
Alex Elder 已提交
1479
static void obj_request_done_set(struct rbd_obj_request *obj_request)
1480
{
A
Alex Elder 已提交
1481 1482
	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1483

A
Alex Elder 已提交
1484 1485
		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1486
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1487 1488 1489 1490
			obj_request);
	}
}

A
Alex Elder 已提交
1491
static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1492 1493
{
	smp_mb();
A
Alex Elder 已提交
1494
	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
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 1527
/*
 * 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;
}

1528 1529 1530 1531 1532 1533 1534 1535
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
Alex Elder 已提交
1536 1537
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1538 1539
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1540 1541 1542 1543 1544 1545 1546
	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
1547 1548
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1549 1550 1551
	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1552 1553 1554 1555 1556 1557 1558
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);
}

1559 1560
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
A
Alex Elder 已提交
1561 1562 1563 1564
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
Alex Elder 已提交
1565 1566
	dout("%s: img %p (was %d)\n", __func__, img_request,
		atomic_read(&img_request->kref.refcount));
1567 1568 1569 1570
	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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1571 1572 1573 1574 1575
}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1576 1577
	rbd_assert(obj_request->img_request == NULL);

1578
	/* Image request now owns object's original reference */
A
Alex Elder 已提交
1579
	obj_request->img_request = img_request;
1580
	obj_request->which = img_request->obj_request_count;
1581 1582
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
A
Alex Elder 已提交
1583
	rbd_assert(obj_request->which != BAD_WHICH);
1584 1585
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
A
Alex Elder 已提交
1586 1587
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
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1588 1589 1590 1591 1592 1593
}

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);
1594

A
Alex Elder 已提交
1595 1596
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1597
	list_del(&obj_request->links);
1598 1599 1600 1601
	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;
1602
	rbd_assert(obj_request_img_data_test(obj_request));
A
Alex Elder 已提交
1603 1604
	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1605
	obj_request->callback = NULL;
A
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1606 1607 1608 1609 1610 1611
	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1612
	case OBJ_REQUEST_NODATA:
A
Alex Elder 已提交
1613
	case OBJ_REQUEST_BIO:
1614
	case OBJ_REQUEST_PAGES:
A
Alex Elder 已提交
1615 1616 1617 1618 1619 1620
		return true;
	default:
		return false;
	}
}

1621
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1622
{
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);
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
Alex Elder 已提交
1627 1628
}

1629 1630 1631 1632 1633 1634 1635 1636 1637
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.
1638 1639
 *
 * @timeout: in jiffies, 0 means "wait forever"
1640
 */
1641 1642
static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
				  unsigned long timeout)
1643
{
1644
	long ret;
1645 1646

	dout("%s %p\n", __func__, obj_request);
1647 1648 1649 1650 1651 1652
	ret = wait_for_completion_interruptible_timeout(
					&obj_request->completion,
					ceph_timeout_jiffies(timeout));
	if (ret <= 0) {
		if (ret == 0)
			ret = -ETIMEDOUT;
1653
		rbd_obj_request_end(obj_request);
1654 1655
	} else {
		ret = 0;
1656 1657
	}

1658 1659 1660 1661 1662 1663 1664 1665 1666
	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
1667 1668
static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1669

A
Alex Elder 已提交
1670
	dout("%s: img %p\n", __func__, img_request);
1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686

	/*
	 * 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;
	}

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1687 1688 1689 1690 1691 1692
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
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1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709
/*
 * 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;
}

1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724
/*
 * 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;
}

1725 1726 1727 1728 1729 1730
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1731 1732 1733 1734 1735 1736
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1737 1738 1739 1740 1741 1742
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1743 1744 1745 1746 1747 1748
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1749 1750 1751 1752 1753 1754
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1755 1756 1757 1758 1759 1760
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771
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;
}

1772 1773 1774
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1775 1776 1777
	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1778 1779
	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
1780
		xferred, length);
1781
	/*
1782 1783 1784 1785 1786 1787
	 * 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.
1788
	 */
A
Alex Elder 已提交
1789
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1790
	if (obj_request->result == -ENOENT) {
A
Alex Elder 已提交
1791 1792 1793 1794
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1795
		obj_request->result = 0;
A
Alex Elder 已提交
1796 1797 1798 1799 1800
	} 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);
1801
	}
1802
	obj_request->xferred = length;
1803 1804 1805
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1806 1807
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1808 1809
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
A
Alex Elder 已提交
1810 1811
	if (obj_request->callback)
		obj_request->callback(obj_request);
1812 1813
	else
		complete_all(&obj_request->completion);
A
Alex Elder 已提交
1814 1815
}

1816
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1817
{
A
Alex Elder 已提交
1818
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1819
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1820 1821 1822 1823 1824
	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
1825
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1826
	}
A
Alex Elder 已提交
1827 1828 1829 1830

	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
1831 1832
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1833 1834
		rbd_img_parent_read(obj_request);
	else if (img_request)
1835 1836 1837
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1838 1839
}

1840
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1841
{
1842 1843 1844
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1845 1846
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1847 1848
	 */
	obj_request->xferred = obj_request->length;
1849
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1850 1851
}

1852 1853 1854 1855 1856 1857 1858 1859 1860
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;
1861 1862 1863
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1864 1865 1866
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1867 1868 1869 1870
/*
 * 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.
 */
1871
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1872
{
A
Alex Elder 已提交
1873
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1874 1875 1876
	obj_request_done_set(obj_request);
}

I
Ilya Dryomov 已提交
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886
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);
}

1887
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
Alex Elder 已提交
1888 1889 1890 1891
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

1892
	dout("%s: osd_req %p\n", __func__, osd_req);
A
Alex Elder 已提交
1893
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1894 1895 1896 1897 1898 1899
	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
1900

1901 1902
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1903

1904 1905
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1906 1907
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1908
	 */
1909
	obj_request->xferred = osd_req->r_ops[0].outdata_len;
A
Alex Elder 已提交
1910
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1911

1912
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1913 1914
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1915
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1916
		break;
1917
	case CEPH_OSD_OP_SETALLOCHINT:
1918 1919
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
			   osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1920
		/* fall through */
A
Alex Elder 已提交
1921
	case CEPH_OSD_OP_WRITE:
1922
	case CEPH_OSD_OP_WRITEFULL:
1923
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1924
		break;
A
Alex Elder 已提交
1925
	case CEPH_OSD_OP_STAT:
1926
		rbd_osd_stat_callback(obj_request);
A
Alex Elder 已提交
1927
		break;
1928 1929 1930 1931 1932
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1933
	case CEPH_OSD_OP_CALL:
I
Ilya Dryomov 已提交
1934 1935
		rbd_osd_call_callback(obj_request);
		break;
A
Alex Elder 已提交
1936
	default:
1937
		rbd_warn(NULL, "%s: unsupported op %hu",
A
Alex Elder 已提交
1938 1939 1940 1941
			obj_request->object_name, (unsigned short) opcode);
		break;
	}

1942
	if (obj_request_done_test(obj_request))
A
Alex Elder 已提交
1943 1944 1945
		rbd_obj_request_complete(obj_request);
}

1946
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1947 1948
{
	struct rbd_img_request *img_request = obj_request->img_request;
1949
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1950

1951 1952
	if (img_request)
		osd_req->r_snapid = img_request->snap_id;
1953 1954 1955 1956 1957 1958
}

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

1959 1960
	osd_req->r_mtime = CURRENT_TIME;
	osd_req->r_data_offset = obj_request->offset;
A
Alex Elder 已提交
1961 1962
}

1963 1964 1965 1966 1967 1968
/*
 * 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
1969 1970
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1971
					enum obj_operation_type op_type,
1972
					unsigned int num_ops,
A
Alex Elder 已提交
1973
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1974 1975 1976 1977 1978
{
	struct ceph_snap_context *snapc = NULL;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;

1979 1980
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1981
		struct rbd_img_request *img_request = obj_request->img_request;
1982 1983 1984 1985 1986
		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
1987
		snapc = img_request->snapc;
A
Alex Elder 已提交
1988 1989
	}

G
Guangliang Zhao 已提交
1990
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1991 1992

	/* Allocate and initialize the request, for the num_ops ops */
A
Alex Elder 已提交
1993 1994

	osdc = &rbd_dev->rbd_client->client->osdc;
1995
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
1996
					  GFP_NOIO);
A
Alex Elder 已提交
1997
	if (!osd_req)
1998
		goto fail;
A
Alex Elder 已提交
1999

2000
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
A
Alex Elder 已提交
2001
		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
A
Alex Elder 已提交
2002
	else
A
Alex Elder 已提交
2003 2004 2005 2006 2007
		osd_req->r_flags = CEPH_OSD_FLAG_READ;

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

2008
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2009 2010 2011
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
A
Alex Elder 已提交
2012

2013 2014 2015
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

A
Alex Elder 已提交
2016
	return osd_req;
2017 2018 2019 2020

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
A
Alex Elder 已提交
2021 2022
}

2023
/*
2024 2025 2026 2027
 * 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.
2028 2029 2030 2031 2032 2033 2034 2035 2036
 */
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;
2037
	int num_osd_ops = 3;
2038 2039 2040 2041

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
2042 2043
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
2044

2045 2046 2047 2048
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

	/* Allocate and initialize the request, for all the ops */
2049 2050 2051 2052

	snapc = img_request->snapc;
	rbd_dev = img_request->rbd_dev;
	osdc = &rbd_dev->rbd_client->client->osdc;
2053
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2054
						false, GFP_NOIO);
2055
	if (!osd_req)
2056
		goto fail;
2057 2058 2059 2060 2061

	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;

2062
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2063 2064 2065
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
2066

2067 2068 2069
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

2070
	return osd_req;
2071 2072 2073 2074

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
2075 2076 2077
}


A
Alex Elder 已提交
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095
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;
2096
	name = kmalloc(size, GFP_NOIO);
2097
	if (!name)
A
Alex Elder 已提交
2098 2099
		return NULL;

2100
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2101 2102 2103 2104 2105
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2106 2107 2108
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->offset = offset;
	obj_request->length = length;
2109
	obj_request->flags = 0;
A
Alex Elder 已提交
2110 2111 2112
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2113
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2114 2115
	kref_init(&obj_request->kref);

A
Alex Elder 已提交
2116 2117 2118
	dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
		offset, length, (int)type, obj_request);

A
Alex Elder 已提交
2119 2120 2121 2122 2123 2124 2125 2126 2127
	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
2128 2129
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2130 2131 2132 2133 2134 2135 2136 2137
	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) {
2138 2139
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2140 2141 2142 2143
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2144 2145 2146 2147 2148
	case OBJ_REQUEST_PAGES:
		if (obj_request->pages)
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2149 2150
	}

2151
	kfree(obj_request->object_name);
2152 2153
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2154 2155
}

A
Alex Elder 已提交
2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166
/* 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;
}

2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188
/*
 * 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
2189
		rbd_warn(rbd_dev, "parent reference underflow");
2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201
}

/*
 * 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)
{
2202
	int counter = 0;
2203 2204 2205 2206

	if (!rbd_dev->parent_spec)
		return false;

2207 2208 2209 2210
	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);
2211 2212

	if (counter < 0)
2213
		rbd_warn(rbd_dev, "parent reference overflow");
2214

2215
	return counter > 0;
2216 2217
}

A
Alex Elder 已提交
2218 2219 2220 2221 2222
/*
 * 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
2223 2224
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2225
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2226
					enum obj_operation_type op_type,
2227
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2228 2229 2230
{
	struct rbd_img_request *img_request;

2231
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2232 2233 2234 2235 2236 2237 2238
	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
2239
	img_request->flags = 0;
2240 2241 2242 2243
	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
2244
		img_request_write_set(img_request);
2245
		img_request->snapc = snapc;
A
Alex Elder 已提交
2246
	} else {
A
Alex Elder 已提交
2247
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2248
	}
2249
	if (rbd_dev_parent_get(rbd_dev))
2250
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2251 2252 2253
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2254
	img_request->result = 0;
A
Alex Elder 已提交
2255 2256 2257 2258
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2259
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2260
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2261

A
Alex Elder 已提交
2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272
	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
2273 2274
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2275 2276
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2277
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2278

2279 2280 2281 2282 2283
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2284 2285
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2286
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2287

2288
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2289 2290
}

2291 2292 2293 2294 2295 2296 2297 2298 2299 2300
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;

2301
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2302
						length, OBJ_OP_READ, NULL);
2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327
	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);
}

2328 2329
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2330
	struct rbd_img_request *img_request;
2331 2332
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2333
	bool more;
2334

2335 2336 2337
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2338 2339 2340 2341 2342
	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
2343 2344
		enum obj_operation_type op_type;

2345 2346 2347 2348 2349 2350
		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;
2351

2352
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2353 2354
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2355
		rbd_warn(rbd_dev, "  result %d xferred %x",
2356 2357 2358
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2359 2360 2361 2362 2363
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2364 2365
	}

2366 2367 2368 2369 2370 2371 2372
	/* Image object requests don't own their page array */

	if (obj_request->type == OBJ_REQUEST_PAGES) {
		obj_request->pages = NULL;
		obj_request->page_count = 0;
	}

A
Alex Elder 已提交
2373 2374 2375 2376 2377
	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
2378 2379 2380 2381

		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
2382 2383 2384
	}

	return more;
2385 2386
}

2387 2388 2389 2390 2391 2392
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;

2393
	rbd_assert(obj_request_img_data_test(obj_request));
2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411
	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;
2412
		more = rbd_img_obj_end_request(obj_request);
2413 2414 2415 2416 2417 2418 2419
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2420
	rbd_img_request_put(img_request);
2421 2422 2423 2424 2425

	if (!more)
		rbd_img_request_complete(img_request);
}

2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444
/*
 * 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) {
2445 2446 2447
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461
			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) {
2462 2463 2464 2465
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2466 2467 2468 2469 2470 2471 2472
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2473
	if (opcode == CEPH_OSD_OP_DELETE)
2474
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2475 2476 2477 2478
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493
	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);
}

2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504
/*
 * 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
2505 2506 2507 2508
{
	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
2509
	struct bio *bio_list = NULL;
2510
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2511
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2512
	enum obj_operation_type op_type;
2513
	u64 img_offset;
A
Alex Elder 已提交
2514 2515
	u64 resid;

2516 2517
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2518

2519
	img_offset = img_request->offset;
A
Alex Elder 已提交
2520
	resid = img_request->length;
A
Alex Elder 已提交
2521
	rbd_assert(resid > 0);
2522
	op_type = rbd_img_request_op_type(img_request);
2523 2524 2525

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2526 2527
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2528
	} else if (type == OBJ_REQUEST_PAGES) {
2529 2530 2531
		pages = data_desc;
	}

A
Alex Elder 已提交
2532
	while (resid) {
2533
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2534 2535 2536 2537
		const char *object_name;
		u64 offset;
		u64 length;

2538
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2539 2540
		if (!object_name)
			goto out_unwind;
2541 2542
		offset = rbd_segment_offset(rbd_dev, img_offset);
		length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2543
		obj_request = rbd_obj_request_create(object_name,
2544
						offset, length, type);
2545 2546
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2547 2548
		if (!obj_request)
			goto out_unwind;
2549

2550 2551 2552 2553 2554
		/*
		 * 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
2555

2556 2557 2558 2559 2560 2561 2562 2563 2564
		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,
2565
								GFP_NOIO);
2566
			if (!obj_request->bio_list)
2567
				goto out_unwind;
2568
		} else if (type == OBJ_REQUEST_PAGES) {
2569 2570 2571 2572 2573 2574 2575 2576 2577
			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
2578

G
Guangliang Zhao 已提交
2579 2580 2581
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2582
		if (!osd_req)
2583
			goto out_unwind;
2584

2585
		obj_request->osd_req = osd_req;
2586
		obj_request->callback = rbd_img_obj_callback;
2587
		obj_request->img_offset = img_offset;
2588

2589
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2590

2591
		rbd_img_request_get(img_request);
A
Alex Elder 已提交
2592

2593
		img_offset += length;
A
Alex Elder 已提交
2594 2595 2596 2597 2598 2599 2600
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2601
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2602 2603 2604 2605

	return -ENOMEM;
}

2606
static void
I
Ilya Dryomov 已提交
2607
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2608 2609 2610
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2611
	struct page **pages;
2612 2613
	u32 page_count;

I
Ilya Dryomov 已提交
2614 2615
	dout("%s: obj %p\n", __func__, obj_request);

2616 2617
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2618 2619 2620 2621 2622 2623 2624
	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);

2625 2626
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2627
	obj_request->copyup_pages = NULL;
2628 2629 2630 2631
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2632 2633 2634 2635 2636 2637 2638 2639 2640 2641

	/*
	 * 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
2642
	obj_request_done_set(obj_request);
2643 2644
}

2645 2646 2647 2648
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2649 2650
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2651
	struct page **pages;
2652
	enum obj_operation_type op_type;
2653
	u32 page_count;
2654
	int img_result;
2655
	u64 parent_length;
2656 2657 2658 2659 2660 2661 2662 2663

	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;
2664 2665 2666
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2667 2668 2669

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2670
	rbd_assert(obj_request_type_valid(orig_request->type));
2671
	img_result = img_request->result;
2672 2673
	parent_length = img_request->length;
	rbd_assert(parent_length == img_request->xferred);
2674
	rbd_img_request_put(img_request);
2675

2676 2677
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2678 2679
	rbd_assert(rbd_dev);

2680 2681 2682 2683 2684 2685 2686
	/*
	 * 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);
2687 2688
		rbd_obj_request_submit(orig_request);
		return;
2689
	}
2690

2691
	if (img_result)
2692 2693
		goto out_err;

2694 2695
	/*
	 * The original osd request is of no use to use any more.
2696
	 * We need a new one that can hold the three ops in a copyup
2697 2698 2699
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2700
	img_result = -ENOMEM;
2701 2702 2703
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2704
	rbd_osd_req_destroy(orig_request->osd_req);
2705 2706
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2707
	orig_request->copyup_page_count = page_count;
2708

2709
	/* Initialize the copyup op */
2710

2711
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2712
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2713
						false, false);
2714

2715
	/* Add the other op(s) */
2716

2717 2718
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2719 2720 2721

	/* All set, send it off. */

2722 2723 2724
	rbd_obj_request_submit(orig_request);
	return;

2725 2726 2727
out_err:
	/* Record the error code and complete the request */

2728
	orig_request->result = img_result;
2729 2730 2731
	orig_request->xferred = 0;
	obj_request_done_set(orig_request);
	rbd_obj_request_complete(orig_request);
2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759
}

/*
 * 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.
 *
 * If an error occurs, record it as the result of the original
 * object request and mark it done so it gets completed.
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request = NULL;
	struct rbd_img_request *parent_request = NULL;
	struct rbd_device *rbd_dev;
	u64 img_offset;
	u64 length;
	struct page **pages = NULL;
	u32 page_count;
	int result;

	rbd_assert(obj_request_img_data_test(obj_request));
2760
	rbd_assert(obj_request_type_valid(obj_request->type));
2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773

	img_request = obj_request->img_request;
	rbd_assert(img_request != NULL);
	rbd_dev = img_request->rbd_dev;
	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
2774 2775 2776 2777 2778 2779 2780 2781 2782 2783
	/*
	 * 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;
	}

2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796
	/*
	 * 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;
2797 2798
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2799 2800 2801 2802 2803 2804 2805
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
	parent_request->copyup_pages = pages;
2806
	parent_request->copyup_page_count = page_count;
2807 2808 2809 2810 2811 2812 2813

	parent_request->callback = rbd_img_obj_parent_read_full_callback;
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2814
	parent_request->copyup_page_count = 0;
2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828
	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);
	obj_request->result = result;
	obj_request->xferred = 0;
	obj_request_done_set(obj_request);

	return result;
}

2829 2830 2831
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2832
	struct rbd_device *rbd_dev;
2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843
	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;
2844
	rbd_obj_request_put(orig_request);
2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855
	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);

2856 2857
	/*
	 * If the overlap has become 0 (most likely because the
2858 2859
	 * image has been flattened) we need to re-submit the
	 * original request.
2860 2861 2862
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2863 2864
		rbd_obj_request_submit(orig_request);
		return;
2865
	}
2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878

	/*
	 * 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);
	} else if (result) {
		orig_request->result = result;
2879
		goto out;
2880 2881 2882 2883 2884 2885
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2886
	orig_request->result = rbd_img_obj_request_submit(orig_request);
2887
out:
2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927
	if (orig_request->result)
		rbd_obj_request_complete(orig_request);
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *stat_request;
	struct rbd_device *rbd_dev;
	struct page **pages = NULL;
	u32 page_count;
	size_t size;
	int ret;

	/*
	 * 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);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	ret = -ENOMEM;
	stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
							OBJ_REQUEST_PAGES);
	if (!stat_request)
		goto out;

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

	rbd_assert(obj_request->img_request);
	rbd_dev = obj_request->img_request->rbd_dev;
G
Guangliang Zhao 已提交
2928
	stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
2929
						   stat_request);
2930 2931 2932 2933
	if (!stat_request->osd_req)
		goto out;
	stat_request->callback = rbd_img_obj_exists_callback;

2934
	osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
2935 2936
	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
					false, false);
2937
	rbd_osd_req_format_read(stat_request);
2938

2939 2940 2941
	rbd_obj_request_submit(stat_request);
	return 0;

2942 2943 2944 2945 2946 2947 2948
out:
	if (ret)
		rbd_obj_request_put(obj_request);

	return ret;
}

2949
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2950 2951
{
	struct rbd_img_request *img_request;
A
Alex Elder 已提交
2952
	struct rbd_device *rbd_dev;
2953 2954 2955 2956 2957

	rbd_assert(obj_request_img_data_test(obj_request));

	img_request = obj_request->img_request;
	rbd_assert(img_request);
A
Alex Elder 已提交
2958
	rbd_dev = img_request->rbd_dev;
2959

2960
	/* Reads */
2961 2962
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2963 2964 2965 2966 2967 2968
		return true;

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

2969
	/*
2970 2971
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2972
	 */
2973 2974
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2975

2976 2977 2978 2979 2980 2981 2982 2983
	/*
	 * 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;

2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997
	/*
	 * 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)
{
	if (img_obj_request_simple(obj_request)) {
2998 2999
		rbd_obj_request_submit(obj_request);
		return 0;
3000 3001 3002
	}

	/*
3003 3004 3005 3006
	 * 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.
3007
	 */
3008
	if (obj_request_known_test(obj_request))
3009 3010 3011
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
3012 3013 3014 3015

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
3016 3017 3018
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
3019
	struct rbd_obj_request *next_obj_request;
3020
	int ret = 0;
A
Alex Elder 已提交
3021

A
Alex Elder 已提交
3022
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
3023

3024 3025
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
3026
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
3027
		if (ret)
3028
			goto out_put_ireq;
A
Alex Elder 已提交
3029 3030
	}

3031 3032 3033
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
3034
}
A
Alex Elder 已提交
3035 3036 3037 3038

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
3039 3040
	struct rbd_device *rbd_dev;
	u64 obj_end;
3041 3042
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
3043 3044 3045

	rbd_assert(img_request_child_test(img_request));

3046 3047
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
3048
	obj_request = img_request->obj_request;
3049 3050 3051 3052 3053 3054 3055 3056 3057
	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
3058 3059
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
3060 3061
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
3062 3063
		rbd_obj_request_submit(obj_request);
		return;
3064
	}
A
Alex Elder 已提交
3065

3066
	obj_request->result = img_result;
A
Alex Elder 已提交
3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084
	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
3085

3086
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
3087
	} else {
3088
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
3089 3090
	}
out:
A
Alex Elder 已提交
3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102
	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);
3103
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3104 3105

	/* rbd_read_finish(obj_request, obj_request->length); */
3106
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
3107
						obj_request->img_offset,
3108
						obj_request->length);
A
Alex Elder 已提交
3109 3110 3111 3112
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

3113 3114 3115 3116 3117 3118
	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
3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134
	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
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 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202
static const struct rbd_client_id rbd_empty_cid;

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)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
	char cookie[32];
	int ret;

	WARN_ON(__rbd_is_lock_owner(rbd_dev));

	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);
	if (ret)
		return ret;

	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;
}

/*
 * lock_rwsem must be held for write
 */
static int rbd_unlock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3203
{
3204
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3205
	char cookie[32];
3206
	int ret;
A
Alex Elder 已提交
3207

3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280
	WARN_ON(!__rbd_is_lock_owner(rbd_dev));

	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;

	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;
	}

	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
	return 0;
}

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)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	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;

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

	/* 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);

	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
}

static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
{
	struct page **reply_pages;
	size_t reply_len;

	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}

static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);

	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
}

static void rbd_notify_released_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);

	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
}

static int rbd_request_lock(struct rbd_device *rbd_dev)
{
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
	int ret;
3281

3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 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 3578 3579
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	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);
		goto out;
	}

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

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

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

			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);
3580
	/*
3581
	 * Ensure that all in-flight IO is flushed.
3582
	 *
3583 3584
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
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 3731 3732
	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
3733

3734 3735
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3736
				   buf, buf_size);
3737
	if (ret)
3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 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 3818 3819
		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;
	u8 struct_v;
	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
3820 3821
}

3822 3823
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3824
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3825
{
3826
	struct rbd_device *rbd_dev = arg;
3827

3828
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3829

3830 3831 3832 3833
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3834 3835 3836 3837
	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;
3838

3839
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3840
	}
3841
	mutex_unlock(&rbd_dev->watch_mutex);
3842 3843
}

3844
/*
3845
 * watch_mutex must be locked
3846
 */
3847
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3848 3849
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3850
	struct ceph_osd_linger_request *handle;
3851

3852
	rbd_assert(!rbd_dev->watch_handle);
3853
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3854

3855 3856 3857 3858 3859
	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);
3860

3861
	rbd_dev->watch_handle = handle;
3862 3863 3864
	return 0;
}

3865 3866 3867 3868
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3869
{
3870 3871
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3872

3873 3874
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3875

3876 3877 3878
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3879

3880
	rbd_dev->watch_handle = NULL;
3881 3882
}

3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901
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)
3902
{
3903 3904 3905
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3906 3907 3908 3909
	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);
3910 3911 3912 3913
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3914
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3915 3916 3917 3918 3919 3920 3921
	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
3922 3923

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3924 3925
}

3926 3927 3928 3929
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);
3930
	bool was_lock_owner = false;
3931 3932 3933 3934
	int ret;

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

3935 3936 3937 3938
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		was_lock_owner = rbd_release_lock(rbd_dev);

3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960
	mutex_lock(&rbd_dev->watch_mutex);
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR)
		goto fail_unlock;

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
		if (ret != -EBLACKLISTED)
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
		goto fail_unlock;
	}

	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);

3961 3962 3963 3964 3965 3966 3967 3968 3969
	if (was_lock_owner) {
		ret = rbd_try_lock(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "reregisteration lock failed: %d",
				 ret);
	}

	up_write(&rbd_dev->lock_rwsem);
	wake_requests(rbd_dev, true);
3970 3971 3972 3973
	return;

fail_unlock:
	mutex_unlock(&rbd_dev->watch_mutex);
3974
	up_write(&rbd_dev->lock_rwsem);
3975 3976
}

3977
/*
3978 3979
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3980 3981 3982 3983 3984
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
			     const char *object_name,
			     const char *class_name,
			     const char *method_name,
3985
			     const void *outbound,
3986
			     size_t outbound_size,
3987
			     void *inbound,
3988
			     size_t inbound_size)
3989 3990 3991 3992 3993 3994 3995
{
	struct rbd_obj_request *obj_request;
	struct page **pages;
	u32 page_count;
	int ret;

	/*
3996 3997 3998 3999 4000
	 * 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.
4001
	 */
4002
	page_count = (u32)calc_pages_for(0, inbound_size);
4003 4004 4005 4006 4007
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	ret = -ENOMEM;
4008
	obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
4009 4010 4011 4012 4013 4014 4015
							OBJ_REQUEST_PAGES);
	if (!obj_request)
		goto out;

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

G
Guangliang Zhao 已提交
4016
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4017
						  obj_request);
4018 4019 4020
	if (!obj_request->osd_req)
		goto out;

4021
	osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034
					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);
	}
4035 4036
	osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
					obj_request->pages, inbound_size,
4037
					0, false, false);
4038
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
4039

4040
	rbd_obj_request_submit(obj_request);
4041 4042 4043 4044 4045 4046 4047
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
4048 4049 4050

	rbd_assert(obj_request->xferred < (u64)INT_MAX);
	ret = (int)obj_request->xferred;
4051
	ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
4052 4053 4054 4055 4056 4057 4058 4059 4060
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083
/*
 * 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);
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
4084
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
4085
{
C
Christoph Hellwig 已提交
4086 4087
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
4088
	struct rbd_img_request *img_request;
4089
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
4090 4091
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
4092
	enum obj_operation_type op_type;
4093
	u64 mapping_size;
I
Ilya Dryomov 已提交
4094
	bool must_be_locked;
A
Alex Elder 已提交
4095 4096
	int result;

C
Christoph Hellwig 已提交
4097 4098 4099 4100 4101 4102 4103
	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
4104
	if (req_op(rq) == REQ_OP_DISCARD)
4105
		op_type = OBJ_OP_DISCARD;
M
Mike Christie 已提交
4106
	else if (req_op(rq) == REQ_OP_WRITE)
G
Guangliang Zhao 已提交
4107 4108 4109 4110
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
4111
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4112

I
Ilya Dryomov 已提交
4113 4114 4115 4116 4117
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4118

G
Guangliang Zhao 已提交
4119
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
4120

G
Guangliang Zhao 已提交
4121
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
4122 4123 4124
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
4125
		}
I
Ilya Dryomov 已提交
4126 4127
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
4128

I
Ilya Dryomov 已提交
4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140
	/*
	 * 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
4141

I
Ilya Dryomov 已提交
4142 4143 4144 4145 4146 4147
	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
4148

C
Christoph Hellwig 已提交
4149 4150
	blk_mq_start_request(rq);

4151 4152
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4153
	if (op_type != OBJ_OP_READ) {
4154 4155
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
4156
		must_be_locked = rbd_is_lock_supported(rbd_dev);
I
Ilya Dryomov 已提交
4157 4158 4159
	} else {
		must_be_locked = rbd_dev->opts->lock_on_read &&
					rbd_is_lock_supported(rbd_dev);
4160 4161 4162 4163
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4164
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4165
			 length, mapping_size);
I
Ilya Dryomov 已提交
4166 4167 4168
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4169

4170 4171 4172 4173 4174 4175
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
			rbd_wait_state_locked(rbd_dev);
	}

G
Guangliang Zhao 已提交
4176
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4177
					     snapc);
I
Ilya Dryomov 已提交
4178 4179
	if (!img_request) {
		result = -ENOMEM;
4180
		goto err_unlock;
I
Ilya Dryomov 已提交
4181 4182
	}
	img_request->rq = rq;
4183
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4184

4185 4186 4187 4188 4189 4190
	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
4191 4192
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4193

I
Ilya Dryomov 已提交
4194 4195 4196
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4197

4198 4199
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4200
	return;
A
Alex Elder 已提交
4201

I
Ilya Dryomov 已提交
4202 4203
err_img_request:
	rbd_img_request_put(img_request);
4204 4205 4206
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4207 4208 4209
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4210
			 obj_op_name(op_type), length, offset, result);
4211
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4212 4213
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
4214
}
A
Alex Elder 已提交
4215

C
Christoph Hellwig 已提交
4216 4217
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4218
{
C
Christoph Hellwig 已提交
4219 4220
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4221

C
Christoph Hellwig 已提交
4222 4223
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
4224 4225
}

4226 4227 4228 4229 4230 4231 4232
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

4233 4234
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
4235
		del_gendisk(disk);
4236 4237
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
4238
		blk_mq_free_tag_set(&rbd_dev->tag_set);
4239
	}
4240 4241 4242
	put_disk(disk);
}

4243 4244
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
				const char *object_name,
4245
				u64 offset, u64 length, void *buf)
4246 4247 4248 4249 4250

{
	struct rbd_obj_request *obj_request;
	struct page **pages = NULL;
	u32 page_count;
4251
	size_t size;
4252 4253 4254 4255 4256
	int ret;

	page_count = (u32) calc_pages_for(offset, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
4257
		return PTR_ERR(pages);
4258 4259 4260

	ret = -ENOMEM;
	obj_request = rbd_obj_request_create(object_name, offset, length,
4261
							OBJ_REQUEST_PAGES);
4262 4263 4264 4265 4266 4267
	if (!obj_request)
		goto out;

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

G
Guangliang Zhao 已提交
4268
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4269
						  obj_request);
4270 4271 4272
	if (!obj_request->osd_req)
		goto out;

4273 4274
	osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
					offset, length, 0, 0);
4275
	osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
4276
					obj_request->pages,
4277 4278 4279
					obj_request->length,
					obj_request->offset & ~PAGE_MASK,
					false, false);
4280
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
4281

4282
	rbd_obj_request_submit(obj_request);
4283 4284 4285 4286 4287 4288 4289
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
4290 4291 4292

	rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
	size = (size_t) obj_request->xferred;
4293
	ceph_copy_from_page_vector(pages, buf, 0, size);
4294 4295
	rbd_assert(size <= (size_t)INT_MAX);
	ret = (int)size;
4296 4297 4298 4299 4300 4301 4302 4303 4304
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

4305
/*
A
Alex Elder 已提交
4306 4307 4308
 * 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.
4309
 */
4310
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4311
{
4312
	struct rbd_image_header_ondisk *ondisk = NULL;
4313
	u32 snap_count = 0;
4314 4315 4316
	u64 names_size = 0;
	u32 want_count;
	int ret;
4317

A
Alex Elder 已提交
4318
	/*
4319 4320 4321 4322 4323
	 * 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
4324
	 */
4325 4326 4327 4328 4329 4330 4331 4332 4333 4334
	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
4335
			return -ENOMEM;
4336

4337
		ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_oid.name,
4338
				       0, size, ondisk);
4339
		if (ret < 0)
A
Alex Elder 已提交
4340
			goto out;
A
Alex Elder 已提交
4341
		if ((size_t)ret < size) {
4342
			ret = -ENXIO;
A
Alex Elder 已提交
4343 4344
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4345
			goto out;
4346 4347 4348
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4349
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4350
			goto out;
4351
		}
4352

4353 4354 4355 4356
		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
4357

A
Alex Elder 已提交
4358 4359
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4360 4361 4362
	kfree(ondisk);

	return ret;
4363 4364
}

4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383
/*
 * 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);
}

4384 4385 4386 4387 4388
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4389 4390 4391
	 * 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.
4392
	 */
I
Ilya Dryomov 已提交
4393 4394
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4395 4396 4397 4398 4399 4400 4401
		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
4402
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4403
{
4404
	u64 mapping_size;
A
Alex Elder 已提交
4405 4406
	int ret;

4407
	down_write(&rbd_dev->header_rwsem);
4408
	mapping_size = rbd_dev->mapping.size;
4409 4410

	ret = rbd_dev_header_info(rbd_dev);
4411
	if (ret)
4412
		goto out;
4413

4414 4415 4416 4417 4418 4419 4420
	/*
	 * 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)
4421
			goto out;
4422 4423
	}

4424
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4425
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4426 4427 4428 4429
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4430

4431
out:
4432
	up_write(&rbd_dev->header_rwsem);
4433
	if (!ret && mapping_size != rbd_dev->mapping.size)
4434
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4435

4436
	return ret;
A
Alex Elder 已提交
4437 4438
}

C
Christoph Hellwig 已提交
4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454
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,
	.map_queue	= blk_mq_map_queue,
	.init_request	= rbd_init_request,
};

4455 4456 4457 4458
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4459
	u64 segment_size;
C
Christoph Hellwig 已提交
4460
	int err;
4461 4462

	/* create gendisk info */
4463 4464 4465
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4466
	if (!disk)
A
Alex Elder 已提交
4467
		return -ENOMEM;
4468

A
Alex Elder 已提交
4469
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4470
		 rbd_dev->dev_id);
4471
	disk->major = rbd_dev->major;
4472
	disk->first_minor = rbd_dev->minor;
4473 4474
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4475 4476 4477
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4478 4479
	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
4480
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4481
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4482
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4483 4484 4485 4486 4487
	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)
4488
		goto out_disk;
4489

C
Christoph Hellwig 已提交
4490 4491 4492 4493 4494 4495
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4496 4497
	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
4498

4499
	/* set io sizes to object size */
A
Alex Elder 已提交
4500 4501
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4502
	q->limits.max_sectors = queue_max_hw_sectors(q);
I
Ilya Dryomov 已提交
4503
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
4504 4505 4506
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4507

4508 4509 4510 4511
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
4512
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4513
	q->limits.discard_zeroes_data = 1;
4514

4515 4516 4517
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
		q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

4518 4519 4520 4521 4522 4523 4524
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4525 4526
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4527 4528
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4529
	return err;
4530 4531
}

4532 4533 4534 4535
/*
  sysfs
*/

A
Alex Elder 已提交
4536 4537 4538 4539 4540
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4541 4542 4543
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4544
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4545

A
Alex Elder 已提交
4546 4547
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4548 4549
}

A
Alex Elder 已提交
4550 4551 4552 4553 4554 4555 4556 4557 4558 4559
/*
 * 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
4560
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4561 4562
}

4563 4564 4565
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4566
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4567

A
Alex Elder 已提交
4568 4569 4570 4571
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4572 4573 4574 4575 4576 4577
}

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
4578

4579
	return sprintf(buf, "%d\n", rbd_dev->minor);
4580 4581
}

4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592
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));
}

4593 4594
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4595
{
A
Alex Elder 已提交
4596
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4597

4598
	return sprintf(buf, "client%lld\n",
4599
		       ceph_client_gid(rbd_dev->rbd_client->client));
4600 4601
}

4602 4603 4604 4605 4606 4607 4608 4609
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);
}

4610 4611 4612 4613 4614 4615 4616 4617
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);
}

4618 4619
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4620
{
A
Alex Elder 已提交
4621
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4622

4623
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4624 4625
}

4626 4627 4628 4629 4630
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);

4631
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4632
			(unsigned long long) rbd_dev->spec->pool_id);
4633 4634
}

4635 4636 4637
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4638
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4639

A
Alex Elder 已提交
4640 4641 4642 4643
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4644 4645
}

A
Alex Elder 已提交
4646 4647 4648 4649 4650
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);

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

A
Alex Elder 已提交
4654 4655 4656 4657
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4658 4659 4660 4661
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4662
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4663

4664
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4665 4666
}

4667 4668 4669 4670 4671 4672 4673 4674
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);
}

4675
/*
4676 4677 4678
 * 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)".
4679 4680
 */
static ssize_t rbd_parent_show(struct device *dev,
4681 4682
			       struct device_attribute *attr,
			       char *buf)
4683 4684
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4685
	ssize_t count = 0;
4686

4687
	if (!rbd_dev->parent)
4688 4689
		return sprintf(buf, "(no parent image)\n");

4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705
	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;
4706 4707
}

4708 4709 4710 4711 4712
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
4713
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4714
	int ret;
4715

A
Alex Elder 已提交
4716
	ret = rbd_dev_refresh(rbd_dev);
4717
	if (ret)
4718
		return ret;
4719

4720
	return size;
4721
}
4722

4723
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4724
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4725
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4726
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4727
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4728
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4729
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4730
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4731
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4732
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4733
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4734
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4735 4736
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4737
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4738
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4739 4740 4741

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4742
	&dev_attr_features.attr,
4743
	&dev_attr_major.attr,
4744
	&dev_attr_minor.attr,
4745
	&dev_attr_client_addr.attr,
4746
	&dev_attr_client_id.attr,
4747
	&dev_attr_cluster_fsid.attr,
4748
	&dev_attr_config_info.attr,
4749
	&dev_attr_pool.attr,
4750
	&dev_attr_pool_id.attr,
4751
	&dev_attr_name.attr,
A
Alex Elder 已提交
4752
	&dev_attr_image_id.attr,
4753
	&dev_attr_current_snap.attr,
4754
	&dev_attr_snap_id.attr,
4755
	&dev_attr_parent.attr,
4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768
	&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
};

4769
static void rbd_dev_release(struct device *dev);
4770 4771 4772 4773

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4774
	.release	= rbd_dev_release,
4775 4776
};

4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797
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;
4798 4799 4800

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816
	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);
}

4817
static void rbd_dev_free(struct rbd_device *rbd_dev)
4818
{
4819
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4820
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4821

4822
	ceph_oid_destroy(&rbd_dev->header_oid);
4823
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4824
	kfree(rbd_dev->config_info);
4825

4826 4827 4828 4829
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842
}

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);
4843 4844 4845 4846 4847 4848 4849 4850 4851 4852

	/*
	 * 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);
}

4853 4854
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4855 4856 4857
{
	struct rbd_device *rbd_dev;

4858
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4859 4860 4861 4862 4863 4864 4865
	if (!rbd_dev)
		return NULL;

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

4866
	ceph_oid_init(&rbd_dev->header_oid);
4867
	ceph_oloc_init(&rbd_dev->header_oloc);
4868

4869 4870 4871 4872
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4873 4874 4875 4876 4877 4878 4879 4880
	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);

4881 4882 4883 4884 4885
	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);

4886
	rbd_dev->rbd_client = rbdc;
4887
	rbd_dev->spec = spec;
4888

4889 4890 4891 4892
	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;
4893
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
4894

4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924
	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;
4925

4926 4927 4928 4929
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);

	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4930
	return rbd_dev;
4931 4932 4933 4934 4935 4936

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4937 4938 4939 4940
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4941 4942
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4943 4944
}

4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959
/*
 * 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 };

4960
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4961
				"rbd", "get_size",
4962
				&snapid, sizeof (snapid),
4963
				&size_buf, sizeof (size_buf));
4964
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4965 4966
	if (ret < 0)
		return ret;
4967 4968
	if (ret < sizeof (size_buf))
		return -ERANGE;
4969

J
Josh Durgin 已提交
4970
	if (order) {
4971
		*order = size_buf.order;
J
Josh Durgin 已提交
4972 4973
		dout("  order %u", (unsigned int)*order);
	}
4974 4975
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4976 4977
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4978
		(unsigned long long)*snap_size);
4979 4980 4981 4982 4983 4984 4985 4986 4987 4988 4989

	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);
}

4990 4991 4992 4993 4994 4995 4996 4997 4998 4999
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;

5000
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5001
				"rbd", "get_object_prefix", NULL, 0,
5002
				reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
5003
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5004 5005 5006 5007 5008
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5009 5010
						p + ret, NULL, GFP_NOIO);
	ret = 0;
5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023

	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;
}

5024 5025 5026 5027 5028 5029 5030
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;
5031
	} __attribute__ ((packed)) features_buf = { 0 };
5032
	u64 unsup;
5033 5034
	int ret;

5035
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5036
				"rbd", "get_features",
5037
				&snapid, sizeof (snapid),
5038
				&features_buf, sizeof (features_buf));
5039
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5040 5041
	if (ret < 0)
		return ret;
5042 5043
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
5044

5045 5046 5047 5048
	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
5049
		return -ENXIO;
5050
	}
A
Alex Elder 已提交
5051

5052 5053 5054
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5055 5056 5057
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
5058 5059 5060 5061 5062 5063 5064 5065 5066 5067

	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);
}

5068 5069 5070 5071 5072 5073 5074 5075
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
5076
	u64 pool_id;
5077
	char *image_id;
5078
	u64 snap_id;
5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095
	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;
	}

5096
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5097
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5098
				"rbd", "get_parent",
5099
				&snapid, sizeof (snapid),
5100
				reply_buf, size);
5101
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5102 5103 5104 5105
	if (ret < 0)
		goto out_err;

	p = reply_buf;
5106 5107
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
5108
	ceph_decode_64_safe(&p, end, pool_id, out_err);
5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125
	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);
		}

5126
		goto out;	/* No parent?  No problem. */
5127
	}
5128

5129 5130 5131
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5132
	if (pool_id > (u64)U32_MAX) {
5133
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5134
			(unsigned long long)pool_id, U32_MAX);
5135
		goto out_err;
A
Alex Elder 已提交
5136
	}
5137

A
Alex Elder 已提交
5138
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5139 5140 5141 5142
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5143
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5144 5145
	ceph_decode_64_safe(&p, end, overlap, out_err);

5146 5147 5148 5149 5150 5151 5152 5153 5154
	/*
	 * 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
5155 5156
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5157 5158
	} else {
		kfree(image_id);
5159 5160 5161
	}

	/*
5162 5163
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5164 5165 5166
	 */
	if (!overlap) {
		if (parent_spec) {
5167 5168 5169 5170
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5171
		} else {
5172 5173
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5174
		}
A
Alex Elder 已提交
5175
	}
5176 5177
	rbd_dev->parent_overlap = overlap;

5178 5179 5180 5181 5182 5183 5184 5185 5186
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199
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;

5200
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5201
				"rbd", "get_stripe_unit_count", NULL, 0,
5202
				(char *)&striping_info_buf, size);
5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230
	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;
	}
5231 5232
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5233 5234 5235 5236

	return 0;
}

5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250
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
5251 5252
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5253 5254 5255 5256 5257
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5258
	end = image_id + image_id_size;
5259
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5260 5261 5262 5263 5264 5265

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

5266
	ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
5267 5268
				"rbd", "dir_get_name",
				image_id, image_id_size,
5269
				reply_buf, size);
5270 5271 5272
	if (ret < 0)
		goto out;
	p = reply_buf;
5273 5274
	end = reply_buf + ret;

5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286
	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;
}

5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316
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);
5317 5318 5319 5320 5321 5322 5323
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5324 5325 5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341
		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);
}

5342
/*
5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369
 * 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.
5370
 *
5371 5372
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5373
 */
5374
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5375
{
5376 5377 5378 5379 5380
	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;
5381 5382
	int ret;

5383 5384 5385
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5386

5387
	/* Get the pool name; we have to make our own copy of this */
5388

5389 5390 5391
	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);
5392 5393
		return -EIO;
	}
5394 5395
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5396 5397 5398 5399
		return -ENOMEM;

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

5400 5401
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5402
		rbd_warn(rbd_dev, "unable to get image name");
5403

5404
	/* Fetch the snapshot name */
5405

5406
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5407 5408
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5409
		goto out_err;
5410 5411 5412 5413 5414
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5415 5416

	return 0;
5417

5418
out_err:
5419 5420
	kfree(image_name);
	kfree(pool_name);
5421 5422 5423
	return ret;
}

A
Alex Elder 已提交
5424
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5425 5426 5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447
{
	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;

5448
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5449
				"rbd", "get_snapcontext", NULL, 0,
5450
				reply_buf, size);
5451
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5452 5453 5454 5455
	if (ret < 0)
		goto out;

	p = reply_buf;
5456 5457
	end = reply_buf + ret;
	ret = -ERANGE;
5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473
	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;
5474
	ret = 0;
5475

5476
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5477 5478 5479 5480 5481 5482 5483 5484
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5485
	ceph_put_snap_context(rbd_dev->header.snapc);
5486 5487 5488
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5489
		(unsigned long long)seq, (unsigned int)snap_count);
5490 5491 5492
out:
	kfree(reply_buf);

5493
	return ret;
5494 5495
}

5496 5497
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5498 5499 5500
{
	size_t size;
	void *reply_buf;
5501
	__le64 snapid;
A
Alex Elder 已提交
5502 5503 5504 5505 5506 5507 5508 5509 5510 5511
	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);

5512
	snapid = cpu_to_le64(snap_id);
5513
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
A
Alex Elder 已提交
5514
				"rbd", "get_snapshot_name",
5515
				&snapid, sizeof (snapid),
5516
				reply_buf, size);
5517
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5518 5519
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5520
		goto out;
5521
	}
A
Alex Elder 已提交
5522 5523

	p = reply_buf;
5524
	end = reply_buf + ret;
A
Alex Elder 已提交
5525
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5526
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5527 5528
		goto out;

5529
	dout("  snap_id 0x%016llx snap_name = %s\n",
5530
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5531 5532 5533
out:
	kfree(reply_buf);

5534
	return snap_name;
A
Alex Elder 已提交
5535 5536
}

5537
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5538
{
5539
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5540 5541
	int ret;

5542 5543
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5544
		return ret;
5545

5546 5547 5548
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5549
			return ret;
5550 5551
	}

A
Alex Elder 已提交
5552
	ret = rbd_dev_v2_snap_context(rbd_dev);
5553 5554 5555 5556
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5557 5558 5559 5560

	return ret;
}

5561 5562 5563 5564 5565 5566 5567 5568 5569 5570
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);
}

5571 5572 5573
/*
 * 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
5574 5575
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589
 */
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
5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611
/*
 * 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
5612
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5624
/*
5625 5626 5627 5628
 * 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
5629
 *
5630 5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663
 * 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.
5664
 */
5665
static int rbd_add_parse_args(const char *buf,
5666
				struct ceph_options **ceph_opts,
5667 5668
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5669
{
A
Alex Elder 已提交
5670
	size_t len;
5671
	char *options;
5672
	const char *mon_addrs;
5673
	char *snap_name;
5674
	size_t mon_addrs_size;
5675
	struct rbd_spec *spec = NULL;
5676
	struct rbd_options *rbd_opts = NULL;
5677
	struct ceph_options *copts;
5678
	int ret;
5679 5680 5681

	/* The first four tokens are required */

5682
	len = next_token(&buf);
5683 5684 5685 5686
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5687
	mon_addrs = buf;
5688
	mon_addrs_size = len + 1;
5689
	buf += len;
5690

5691
	ret = -EINVAL;
5692 5693
	options = dup_token(&buf, NULL);
	if (!options)
5694
		return -ENOMEM;
5695 5696 5697 5698
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5699

5700 5701
	spec = rbd_spec_alloc();
	if (!spec)
5702
		goto out_mem;
5703 5704 5705 5706

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5707 5708 5709 5710
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5711

A
Alex Elder 已提交
5712
	spec->image_name = dup_token(&buf, NULL);
5713
	if (!spec->image_name)
5714
		goto out_mem;
5715 5716 5717 5718
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5719

5720 5721 5722 5723
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5724
	len = next_token(&buf);
5725
	if (!len) {
5726 5727
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5728
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5729
		ret = -ENAMETOOLONG;
5730
		goto out_err;
5731
	}
5732 5733
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5734
		goto out_mem;
5735 5736
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5737

5738
	/* Initialize all rbd options to the defaults */
5739

5740 5741 5742 5743 5744
	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
5745
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5746
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
A
Alex Elder 已提交
5747

5748
	copts = ceph_parse_options(options, mon_addrs,
5749
					mon_addrs + mon_addrs_size - 1,
5750
					parse_rbd_opts_token, rbd_opts);
5751 5752
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5753 5754
		goto out_err;
	}
5755 5756 5757
	kfree(options);

	*ceph_opts = copts;
5758
	*opts = rbd_opts;
5759
	*rbd_spec = spec;
5760

5761
	return 0;
5762
out_mem:
5763
	ret = -ENOMEM;
A
Alex Elder 已提交
5764
out_err:
5765 5766
	kfree(rbd_opts);
	rbd_spec_put(spec);
5767
	kfree(options);
A
Alex Elder 已提交
5768

5769
	return ret;
5770 5771
}

5772 5773 5774 5775 5776
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5777
	struct ceph_options *opts = rbdc->client->options;
5778 5779 5780 5781 5782 5783 5784
	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) {
5785 5786
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5787 5788 5789 5790
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5791
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5792
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5793 5794
						     newest_epoch,
						     opts->mount_timeout);
5795 5796 5797 5798 5799 5800 5801 5802 5803 5804
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824
/*
 * 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;
5825
	char *image_id;
5826

A
Alex Elder 已提交
5827 5828 5829
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5830 5831
	 * 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
5832
	 */
5833 5834 5835
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5836
		return 0;
5837
	}
A
Alex Elder 已提交
5838

A
Alex Elder 已提交
5839 5840 5841 5842
	/*
	 * 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
5843
	size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
A
Alex Elder 已提交
5844 5845 5846
	object_name = kmalloc(size, GFP_NOIO);
	if (!object_name)
		return -ENOMEM;
5847
	sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
A
Alex Elder 已提交
5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858
	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;
	}

5859 5860
	/* If it doesn't exist we'll assume it's a format 1 image */

5861
	ret = rbd_obj_method_sync(rbd_dev, object_name,
5862
				"rbd", "get_id", NULL, 0,
5863
				response, RBD_IMAGE_ID_LEN_MAX);
5864
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5865 5866 5867 5868 5869
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5870
	} else if (ret >= 0) {
5871 5872 5873
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5874
						NULL, GFP_NOIO);
5875
		ret = PTR_ERR_OR_ZERO(image_id);
5876 5877 5878 5879 5880 5881 5882
		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
5883 5884 5885 5886 5887 5888 5889 5890
	}
out:
	kfree(response);
	kfree(object_name);

	return ret;
}

A
Alex Elder 已提交
5891 5892 5893 5894
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5895 5896 5897 5898
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5899
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5900 5901 5902 5903

	/* Free dynamic fields from the header, then zero it out */

	header = &rbd_dev->header;
5904
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5905 5906 5907 5908 5909 5910
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5911
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5912 5913 5914
{
	int ret;

5915
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5916
	if (ret)
5917 5918
		goto out_err;

5919 5920 5921 5922
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5923
	ret = rbd_dev_v2_features(rbd_dev);
5924
	if (ret)
5925
		goto out_err;
5926

5927 5928 5929 5930 5931 5932 5933
	/* 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;
	}
5934
	/* No support for crypto and compression type format 2 images */
5935

A
Alex Elder 已提交
5936
	return 0;
5937
out_err:
A
Alex Elder 已提交
5938
	rbd_dev->header.features = 0;
5939 5940
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5941 5942

	return ret;
5943 5944
}

5945 5946 5947 5948 5949 5950
/*
 * @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
5951
{
5952
	struct rbd_device *parent = NULL;
5953 5954 5955 5956 5957
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5958 5959 5960 5961 5962 5963
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5964
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5965 5966
	if (!parent) {
		ret = -ENOMEM;
5967
		goto out_err;
5968 5969 5970 5971 5972 5973 5974 5975
	}

	/*
	 * 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);
5976

5977
	ret = rbd_dev_image_probe(parent, depth);
5978 5979
	if (ret < 0)
		goto out_err;
5980

5981
	rbd_dev->parent = parent;
5982
	atomic_set(&rbd_dev->parent_ref, 1);
5983
	return 0;
5984

5985
out_err:
5986
	rbd_dev_unparent(rbd_dev);
5987
	rbd_dev_destroy(parent);
5988 5989 5990
	return ret;
}

I
Ilya Dryomov 已提交
5991 5992 5993 5994
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5995
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5996
{
A
Alex Elder 已提交
5997
	int ret;
A
Alex Elder 已提交
5998

5999
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
6000

6001 6002 6003
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
6004
			goto err_out_unlock;
6005 6006 6007 6008 6009 6010 6011

		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
6012 6013 6014 6015 6016 6017 6018

	/* Set up the blkdev mapping. */

	ret = rbd_init_disk(rbd_dev);
	if (ret)
		goto err_out_blkdev;

6019
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
6020 6021
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
6022

6023
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6024
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
6025

6026 6027
	dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
	ret = device_add(&rbd_dev->dev);
6028
	if (ret)
6029
		goto err_out_mapping;
A
Alex Elder 已提交
6030 6031 6032

	/* Everything's ready.  Announce the disk to the world. */

6033
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
6034
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6035

6036 6037 6038 6039
	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
6040
	add_disk(rbd_dev->disk);
6041 6042 6043
	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
6044 6045

	return ret;
6046

6047 6048
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
6049 6050 6051
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
6052 6053
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
6054 6055
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6056 6057 6058
	return ret;
}

A
Alex Elder 已提交
6059 6060 6061
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
6062
	int ret;
A
Alex Elder 已提交
6063 6064 6065 6066 6067

	/* Record the header object name for this rbd image. */

	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));

6068
	rbd_dev->header_oloc.pool = rbd_dev->layout.pool_id;
A
Alex Elder 已提交
6069
	if (rbd_dev->image_format == 1)
6070 6071
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
6072
	else
6073 6074
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
6075

6076
	return ret;
A
Alex Elder 已提交
6077 6078
}

6079 6080
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6081 6082 6083 6084 6085
	rbd_dev_unprobe(rbd_dev);
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

6086 6087 6088
	rbd_dev_destroy(rbd_dev);
}

6089 6090
/*
 * Probe for the existence of the header object for the given rbd
6091 6092 6093
 * 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.
6094
 */
6095
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6096 6097 6098 6099
{
	int ret;

	/*
A
Alex Elder 已提交
6100 6101 6102 6103
	 * 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.
6104 6105 6106
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6107 6108
		return ret;

A
Alex Elder 已提交
6109 6110 6111 6112
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6113
	if (!depth) {
6114
		ret = rbd_register_watch(rbd_dev);
6115 6116 6117 6118 6119
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6120
			goto err_out_format;
6121
		}
6122
	}
6123

6124
	ret = rbd_dev_header_info(rbd_dev);
6125
	if (ret)
6126
		goto err_out_watch;
A
Alex Elder 已提交
6127

6128 6129 6130 6131 6132 6133
	/*
	 * 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.
	 */
6134
	if (!depth)
6135 6136 6137
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6138 6139 6140 6141 6142 6143
	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
6144
		goto err_out_probe;
6145
	}
6146

6147 6148 6149 6150 6151 6152 6153 6154 6155
	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.
		 */
6156
		if (!depth && rbd_dev->parent_spec)
6157 6158 6159 6160
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6161
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6162 6163 6164 6165
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6166
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6167
	return 0;
6168

A
Alex Elder 已提交
6169 6170
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6171
err_out_watch:
6172
	if (!depth)
6173
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6174 6175
err_out_format:
	rbd_dev->image_format = 0;
6176 6177
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6178 6179 6180
	return ret;
}

6181 6182 6183
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6184
{
6185
	struct rbd_device *rbd_dev = NULL;
6186
	struct ceph_options *ceph_opts = NULL;
6187
	struct rbd_options *rbd_opts = NULL;
6188
	struct rbd_spec *spec = NULL;
6189
	struct rbd_client *rbdc;
6190
	bool read_only;
6191
	int rc;
6192 6193 6194 6195 6196

	if (!try_module_get(THIS_MODULE))
		return -ENODEV;

	/* parse add command */
6197
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6198
	if (rc < 0)
6199
		goto out;
6200

6201 6202 6203
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6204
		goto err_out_args;
6205
	}
6206 6207

	/* pick the pool */
6208
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6209 6210 6211
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6212
		goto err_out_client;
6213
	}
A
Alex Elder 已提交
6214
	spec->pool_id = (u64)rc;
6215

6216
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6217 6218
	if (!rbd_dev) {
		rc = -ENOMEM;
6219
		goto err_out_client;
6220
	}
6221 6222
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6223
	rbd_opts = NULL;	/* rbd_dev now owns this */
6224

6225 6226 6227 6228 6229 6230
	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
6231
	down_write(&rbd_dev->header_rwsem);
6232
	rc = rbd_dev_image_probe(rbd_dev, 0);
6233 6234
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6235
		goto err_out_rbd_dev;
6236
	}
6237

6238 6239
	/* If we are mapping a snapshot it must be marked read-only */

6240
	read_only = rbd_dev->opts->read_only;
6241 6242 6243 6244
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

6245
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
6246
	if (rc) {
6247
		/*
6248
		 * rbd_unregister_watch() can't be moved into
6249 6250 6251
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
6252
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6253
		rbd_dev_image_release(rbd_dev);
6254
		goto out;
A
Alex Elder 已提交
6255 6256
	}

6257 6258 6259 6260
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6261

6262 6263
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6264
err_out_client:
6265
	rbd_put_client(rbdc);
6266
err_out_args:
6267
	rbd_spec_put(spec);
6268
	kfree(rbd_opts);
6269
	goto out;
6270 6271
}

6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288
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);
}

6289
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6290 6291
{
	rbd_free_disk(rbd_dev);
6292 6293 6294 6295 6296

	spin_lock(&rbd_dev_list_lock);
	list_del_init(&rbd_dev->node);
	spin_unlock(&rbd_dev_list_lock);

6297
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6298
	device_del(&rbd_dev->dev);
A
Alex Elder 已提交
6299
	rbd_dev_mapping_clear(rbd_dev);
6300 6301
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
6302 6303
}

6304 6305
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6306
	while (rbd_dev->parent) {
6307 6308 6309 6310 6311 6312 6313 6314 6315 6316 6317 6318
		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
6319
		rbd_assert(second);
6320
		rbd_dev_image_release(second);
A
Alex Elder 已提交
6321 6322 6323 6324
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6325 6326 6327 6328 6329
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6330 6331 6332
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6333 6334
{
	struct rbd_device *rbd_dev = NULL;
6335 6336
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6337
	char opt_buf[6];
6338
	bool already = false;
M
Mike Christie 已提交
6339
	bool force = false;
6340
	int ret;
6341

M
Mike Christie 已提交
6342 6343 6344 6345 6346
	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");
6347
		return -EINVAL;
M
Mike Christie 已提交
6348 6349 6350 6351 6352 6353 6354 6355 6356
	}
	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;
		}
	}
6357

6358 6359 6360 6361 6362 6363 6364 6365
	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;
		}
6366
	}
6367 6368
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6369
		if (rbd_dev->open_count && !force)
6370 6371
			ret = -EBUSY;
		else
6372 6373
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6374 6375 6376
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6377
	if (ret < 0 || already)
6378
		return ret;
6379

M
Mike Christie 已提交
6380 6381 6382 6383 6384 6385 6386 6387 6388
	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);
	}

6389 6390 6391 6392
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
6393
	rbd_unregister_watch(rbd_dev);
6394

6395 6396 6397 6398 6399 6400
	/*
	 * 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.
	 */
6401
	rbd_dev_device_release(rbd_dev);
6402
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
6403

6404
	return count;
6405 6406
}

6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419 6420 6421 6422 6423
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);
}

6424 6425
/*
 * create control files in sysfs
6426
 * /sys/bus/rbd/...
6427 6428 6429
 */
static int rbd_sysfs_init(void)
{
6430
	int ret;
6431

6432
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6433
	if (ret < 0)
6434
		return ret;
6435

6436 6437 6438
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6439 6440 6441 6442 6443 6444

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6445
	bus_unregister(&rbd_bus_type);
6446
	device_unregister(&rbd_root_dev);
6447 6448
}

6449 6450 6451
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6452
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6453 6454 6455 6456
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6457
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6458 6459 6460 6461 6462
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6463
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6464
	if (rbd_segment_name_cache)
6465
		return 0;
6466
out_err:
6467 6468
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6469

6470 6471 6472
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

6473 6474 6475 6476 6477
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6478 6479 6480 6481
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

6482 6483 6484 6485
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6486 6487 6488 6489 6490
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
6491
static int __init rbd_init(void)
6492 6493 6494
{
	int rc;

6495 6496 6497 6498
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6499

6500
	rc = rbd_slab_init();
6501 6502
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6503

6504 6505
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6506
	 * rbd devices * queue depth, so leave @max_active at default.
6507 6508 6509 6510 6511 6512 6513
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6514 6515 6516 6517
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6518
			goto err_out_wq;
6519 6520 6521
		}
	}

6522 6523
	rc = rbd_sysfs_init();
	if (rc)
6524 6525 6526 6527 6528 6529
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6530

I
Ilya Dryomov 已提交
6531 6532
	return 0;

6533 6534 6535
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6536 6537
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6538 6539
err_out_slab:
	rbd_slab_exit();
6540
	return rc;
6541 6542
}

A
Alex Elder 已提交
6543
static void __exit rbd_exit(void)
6544
{
I
Ilya Dryomov 已提交
6545
	ida_destroy(&rbd_dev_id_ida);
6546
	rbd_sysfs_cleanup();
6547 6548
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6549
	destroy_workqueue(rbd_wq);
6550
	rbd_slab_exit();
6551 6552 6553 6554 6555
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6556
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6557 6558 6559 6560 6561
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>");

6562
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6563
MODULE_LICENSE("GPL");