rbd.c 166.7 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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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
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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

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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;

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	rbd_assert(length <= U64_MAX - offset);
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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;
	}
}

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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;
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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
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1440
		off += bi_size;
1441
		if (off == bi->bi_iter.bi_size) {
A
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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
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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
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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
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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
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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
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1615 1616 1617 1618 1619 1620
		return true;
	default:
		return false;
	}
}

1621 1622
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

1623
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1624
{
1625 1626 1627
	struct ceph_osd_request *osd_req = obj_request->osd_req;

	dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
1628 1629 1630 1631
	if (obj_request_img_data_test(obj_request)) {
		WARN_ON(obj_request->callback != rbd_img_obj_callback);
		rbd_img_request_get(obj_request->img_request);
	}
1632
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
Alex Elder 已提交
1633 1634
}

1635 1636 1637 1638 1639 1640 1641 1642 1643
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.
1644 1645
 *
 * @timeout: in jiffies, 0 means "wait forever"
1646
 */
1647 1648
static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
				  unsigned long timeout)
1649
{
1650
	long ret;
1651 1652

	dout("%s %p\n", __func__, obj_request);
1653 1654 1655 1656 1657 1658
	ret = wait_for_completion_interruptible_timeout(
					&obj_request->completion,
					ceph_timeout_jiffies(timeout));
	if (ret <= 0) {
		if (ret == 0)
			ret = -ETIMEDOUT;
1659
		rbd_obj_request_end(obj_request);
1660 1661
	} else {
		ret = 0;
1662 1663
	}

1664 1665 1666 1667 1668 1669 1670 1671 1672
	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
1673 1674
static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1675

A
Alex Elder 已提交
1676
	dout("%s: img %p\n", __func__, img_request);
1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692

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

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

A
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1693 1694 1695 1696 1697 1698
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
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1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715
/*
 * 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;
}

1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
/*
 * 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;
}

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

1737 1738 1739 1740 1741 1742
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1743 1744 1745 1746 1747 1748
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

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

1755 1756 1757 1758 1759 1760
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1761 1762 1763 1764 1765 1766
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777
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;
}

1778 1779 1780
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1781 1782 1783
	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1784 1785
	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
1786
		xferred, length);
1787
	/*
1788 1789 1790 1791 1792 1793
	 * 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.
1794
	 */
A
Alex Elder 已提交
1795
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1796
	if (obj_request->result == -ENOENT) {
A
Alex Elder 已提交
1797 1798 1799 1800
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1801
		obj_request->result = 0;
A
Alex Elder 已提交
1802 1803 1804 1805 1806
	} 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);
1807
	}
1808
	obj_request->xferred = length;
1809 1810 1811
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1812 1813
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1814 1815
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
A
Alex Elder 已提交
1816 1817
	if (obj_request->callback)
		obj_request->callback(obj_request);
1818 1819
	else
		complete_all(&obj_request->completion);
A
Alex Elder 已提交
1820 1821
}

1822
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1823
{
A
Alex Elder 已提交
1824
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1825
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1826 1827 1828 1829 1830
	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
1831
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1832
	}
A
Alex Elder 已提交
1833 1834 1835 1836

	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
1837 1838
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1839 1840
		rbd_img_parent_read(obj_request);
	else if (img_request)
1841 1842 1843
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1844 1845
}

1846
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1847
{
1848 1849 1850
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1851 1852
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1853 1854
	 */
	obj_request->xferred = obj_request->length;
1855
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1856 1857
}

1858 1859 1860 1861 1862 1863 1864 1865 1866
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;
1867 1868 1869
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1870 1871 1872
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1873 1874 1875 1876
/*
 * 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.
 */
1877
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1878
{
A
Alex Elder 已提交
1879
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1880 1881 1882
	obj_request_done_set(obj_request);
}

I
Ilya Dryomov 已提交
1883 1884 1885 1886 1887 1888 1889 1890 1891 1892
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);
}

1893
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
Alex Elder 已提交
1894 1895 1896 1897
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

1898
	dout("%s: osd_req %p\n", __func__, osd_req);
A
Alex Elder 已提交
1899
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1900 1901 1902 1903 1904 1905
	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
1906

1907 1908
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1909

1910 1911
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1912 1913
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1914
	 */
1915
	obj_request->xferred = osd_req->r_ops[0].outdata_len;
A
Alex Elder 已提交
1916
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1917

1918
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1919 1920
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1921
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1922
		break;
1923
	case CEPH_OSD_OP_SETALLOCHINT:
1924 1925
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
			   osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1926
		/* fall through */
A
Alex Elder 已提交
1927
	case CEPH_OSD_OP_WRITE:
1928
	case CEPH_OSD_OP_WRITEFULL:
1929
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1930
		break;
A
Alex Elder 已提交
1931
	case CEPH_OSD_OP_STAT:
1932
		rbd_osd_stat_callback(obj_request);
A
Alex Elder 已提交
1933
		break;
1934 1935 1936 1937 1938
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1939
	case CEPH_OSD_OP_CALL:
I
Ilya Dryomov 已提交
1940 1941
		rbd_osd_call_callback(obj_request);
		break;
A
Alex Elder 已提交
1942
	default:
1943
		rbd_warn(NULL, "%s: unsupported op %hu",
A
Alex Elder 已提交
1944 1945 1946 1947
			obj_request->object_name, (unsigned short) opcode);
		break;
	}

1948
	if (obj_request_done_test(obj_request))
A
Alex Elder 已提交
1949 1950 1951
		rbd_obj_request_complete(obj_request);
}

1952
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1953 1954
{
	struct rbd_img_request *img_request = obj_request->img_request;
1955
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1956

1957 1958
	if (img_request)
		osd_req->r_snapid = img_request->snap_id;
1959 1960 1961 1962 1963 1964
}

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

1965 1966
	osd_req->r_mtime = CURRENT_TIME;
	osd_req->r_data_offset = obj_request->offset;
A
Alex Elder 已提交
1967 1968
}

1969 1970 1971 1972 1973 1974
/*
 * 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
1975 1976
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1977
					enum obj_operation_type op_type,
1978
					unsigned int num_ops,
A
Alex Elder 已提交
1979
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1980 1981 1982 1983 1984
{
	struct ceph_snap_context *snapc = NULL;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;

1985 1986
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1987
		struct rbd_img_request *img_request = obj_request->img_request;
1988 1989 1990 1991 1992
		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
1993
		snapc = img_request->snapc;
A
Alex Elder 已提交
1994 1995
	}

G
Guangliang Zhao 已提交
1996
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1997 1998

	/* Allocate and initialize the request, for the num_ops ops */
A
Alex Elder 已提交
1999 2000

	osdc = &rbd_dev->rbd_client->client->osdc;
2001
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
2002
					  GFP_NOIO);
A
Alex Elder 已提交
2003
	if (!osd_req)
2004
		goto fail;
A
Alex Elder 已提交
2005

2006
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
A
Alex Elder 已提交
2007
		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
A
Alex Elder 已提交
2008
	else
A
Alex Elder 已提交
2009 2010 2011 2012 2013
		osd_req->r_flags = CEPH_OSD_FLAG_READ;

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

2014
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2015 2016 2017
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
A
Alex Elder 已提交
2018

2019 2020 2021
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

A
Alex Elder 已提交
2022
	return osd_req;
2023 2024 2025 2026

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
A
Alex Elder 已提交
2027 2028
}

2029
/*
2030 2031 2032 2033
 * 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.
2034 2035 2036 2037 2038 2039 2040 2041 2042
 */
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;
2043
	int num_osd_ops = 3;
2044 2045 2046 2047

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
2048 2049
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
2050

2051 2052 2053 2054
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

	/* Allocate and initialize the request, for all the ops */
2055 2056 2057 2058

	snapc = img_request->snapc;
	rbd_dev = img_request->rbd_dev;
	osdc = &rbd_dev->rbd_client->client->osdc;
2059
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2060
						false, GFP_NOIO);
2061
	if (!osd_req)
2062
		goto fail;
2063 2064 2065 2066 2067

	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;

2068
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2069 2070 2071
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
2072

2073 2074 2075
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

2076
	return osd_req;
2077 2078 2079 2080

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
2081 2082 2083
}


A
Alex Elder 已提交
2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
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;
2102
	name = kmalloc(size, GFP_NOIO);
2103
	if (!name)
A
Alex Elder 已提交
2104 2105
		return NULL;

2106
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2107 2108 2109 2110 2111
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2112 2113 2114
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->offset = offset;
	obj_request->length = length;
2115
	obj_request->flags = 0;
A
Alex Elder 已提交
2116 2117 2118
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2119
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2120 2121
	kref_init(&obj_request->kref);

A
Alex Elder 已提交
2122 2123 2124
	dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
		offset, length, (int)type, obj_request);

A
Alex Elder 已提交
2125 2126 2127 2128 2129 2130 2131 2132 2133
	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
2134 2135
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2136 2137 2138 2139 2140 2141 2142 2143
	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) {
2144 2145
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2146 2147 2148 2149
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2150 2151 2152 2153 2154
	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
2155 2156
	}

2157
	kfree(obj_request->object_name);
2158 2159
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2160 2161
}

A
Alex Elder 已提交
2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172
/* 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;
}

2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194
/*
 * 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
2195
		rbd_warn(rbd_dev, "parent reference underflow");
2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207
}

/*
 * 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)
{
2208
	int counter = 0;
2209 2210 2211 2212

	if (!rbd_dev->parent_spec)
		return false;

2213 2214 2215 2216
	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);
2217 2218

	if (counter < 0)
2219
		rbd_warn(rbd_dev, "parent reference overflow");
2220

2221
	return counter > 0;
2222 2223
}

A
Alex Elder 已提交
2224 2225 2226 2227 2228
/*
 * 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
2229 2230
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2231
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2232
					enum obj_operation_type op_type,
2233
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2234 2235 2236
{
	struct rbd_img_request *img_request;

2237
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2238 2239 2240 2241 2242 2243 2244
	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
2245
	img_request->flags = 0;
2246 2247 2248 2249
	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
2250
		img_request_write_set(img_request);
2251
		img_request->snapc = snapc;
A
Alex Elder 已提交
2252
	} else {
A
Alex Elder 已提交
2253
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2254
	}
2255
	if (rbd_dev_parent_get(rbd_dev))
2256
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2257 2258 2259
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2260
	img_request->result = 0;
A
Alex Elder 已提交
2261 2262 2263 2264
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2265
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2266
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2267

A
Alex Elder 已提交
2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278
	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
2279 2280
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2281 2282
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2283
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2284

2285 2286 2287 2288 2289
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2290 2291
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2292
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2293

2294
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2295 2296
}

2297 2298 2299 2300 2301 2302 2303 2304 2305 2306
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;

2307
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2308
						length, OBJ_OP_READ, NULL);
2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333
	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);
}

2334 2335
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2336
	struct rbd_img_request *img_request;
2337 2338
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2339
	bool more;
2340

2341 2342 2343
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2344 2345 2346 2347 2348
	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
2349 2350
		enum obj_operation_type op_type;

2351 2352 2353 2354 2355 2356
		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;
2357

2358
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2359 2360
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2361
		rbd_warn(rbd_dev, "  result %d xferred %x",
2362 2363 2364
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2365 2366 2367 2368 2369
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2370 2371
	}

2372 2373 2374 2375 2376 2377 2378
	/* 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
2379 2380 2381 2382 2383
	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
2384 2385 2386 2387

		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
2388 2389 2390
	}

	return more;
2391 2392
}

2393 2394 2395 2396 2397 2398
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;

2399
	rbd_assert(obj_request_img_data_test(obj_request));
2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417
	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;
2418
		more = rbd_img_obj_end_request(obj_request);
2419 2420 2421 2422 2423 2424 2425
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2426
	rbd_img_request_put(img_request);
2427 2428 2429 2430 2431

	if (!more)
		rbd_img_request_complete(img_request);
}

2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450
/*
 * 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) {
2451 2452 2453
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467
			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) {
2468 2469 2470 2471
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2472 2473 2474 2475 2476 2477 2478
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2479
	if (opcode == CEPH_OSD_OP_DELETE)
2480
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2481 2482 2483 2484
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499
	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);
}

2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510
/*
 * 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
2511 2512 2513 2514
{
	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
2515
	struct bio *bio_list = NULL;
2516
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2517
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2518
	enum obj_operation_type op_type;
2519
	u64 img_offset;
A
Alex Elder 已提交
2520 2521
	u64 resid;

2522 2523
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2524

2525
	img_offset = img_request->offset;
A
Alex Elder 已提交
2526
	resid = img_request->length;
A
Alex Elder 已提交
2527
	rbd_assert(resid > 0);
2528
	op_type = rbd_img_request_op_type(img_request);
2529 2530 2531

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2532 2533
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2534
	} else if (type == OBJ_REQUEST_PAGES) {
2535 2536 2537
		pages = data_desc;
	}

A
Alex Elder 已提交
2538
	while (resid) {
2539
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2540 2541 2542 2543
		const char *object_name;
		u64 offset;
		u64 length;

2544
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2545 2546
		if (!object_name)
			goto out_unwind;
2547 2548
		offset = rbd_segment_offset(rbd_dev, img_offset);
		length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2549
		obj_request = rbd_obj_request_create(object_name,
2550
						offset, length, type);
2551 2552
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2553 2554
		if (!obj_request)
			goto out_unwind;
2555

2556 2557 2558 2559 2560
		/*
		 * 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
2561

2562 2563 2564 2565 2566 2567 2568 2569 2570
		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,
2571
								GFP_NOIO);
2572
			if (!obj_request->bio_list)
2573
				goto out_unwind;
2574
		} else if (type == OBJ_REQUEST_PAGES) {
2575 2576 2577 2578 2579 2580 2581 2582 2583
			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
2584

G
Guangliang Zhao 已提交
2585 2586 2587
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2588
		if (!osd_req)
2589
			goto out_unwind;
2590

2591
		obj_request->osd_req = osd_req;
2592
		obj_request->callback = rbd_img_obj_callback;
2593
		obj_request->img_offset = img_offset;
2594

2595
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2596

2597
		img_offset += length;
A
Alex Elder 已提交
2598 2599 2600 2601 2602 2603 2604
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2605
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2606 2607 2608 2609

	return -ENOMEM;
}

2610
static void
I
Ilya Dryomov 已提交
2611
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2612 2613 2614
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2615
	struct page **pages;
2616 2617
	u32 page_count;

I
Ilya Dryomov 已提交
2618 2619
	dout("%s: obj %p\n", __func__, obj_request);

2620 2621
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2622 2623 2624 2625 2626 2627 2628
	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);

2629 2630
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2631
	obj_request->copyup_pages = NULL;
2632 2633 2634 2635
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2636 2637 2638 2639 2640 2641 2642 2643 2644 2645

	/*
	 * 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
2646
	obj_request_done_set(obj_request);
2647 2648
}

2649 2650 2651 2652
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2653 2654
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2655
	struct page **pages;
2656
	enum obj_operation_type op_type;
2657
	u32 page_count;
2658
	int img_result;
2659
	u64 parent_length;
2660 2661 2662 2663 2664 2665 2666 2667

	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;
2668 2669 2670
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2671 2672 2673

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2674
	rbd_assert(obj_request_type_valid(orig_request->type));
2675
	img_result = img_request->result;
2676
	parent_length = img_request->length;
2677
	rbd_assert(img_result || parent_length == img_request->xferred);
2678
	rbd_img_request_put(img_request);
2679

2680 2681
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2682 2683
	rbd_assert(rbd_dev);

2684 2685 2686 2687 2688 2689 2690
	/*
	 * 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);
2691 2692
		rbd_obj_request_submit(orig_request);
		return;
2693
	}
2694

2695
	if (img_result)
2696 2697
		goto out_err;

2698 2699
	/*
	 * The original osd request is of no use to use any more.
2700
	 * We need a new one that can hold the three ops in a copyup
2701 2702 2703
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2704
	img_result = -ENOMEM;
2705 2706 2707
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2708
	rbd_osd_req_destroy(orig_request->osd_req);
2709 2710
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2711
	orig_request->copyup_page_count = page_count;
2712

2713
	/* Initialize the copyup op */
2714

2715
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2716
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2717
						false, false);
2718

2719
	/* Add the other op(s) */
2720

2721 2722
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2723 2724 2725

	/* All set, send it off. */

2726 2727 2728
	rbd_obj_request_submit(orig_request);
	return;

2729
out_err:
2730
	ceph_release_page_vector(pages, page_count);
2731
	orig_request->result = img_result;
2732
	orig_request->xferred = 0;
2733
	rbd_img_request_get(orig_request->img_request);
2734 2735
	obj_request_done_set(orig_request);
	rbd_obj_request_complete(orig_request);
2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748
}

/*
 * 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.
 *
2749 2750
 * If an error occurs, it is recorded as the result of the original
 * object request in rbd_img_obj_exists_callback().
2751 2752 2753
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
2754
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770
	struct rbd_img_request *parent_request = NULL;
	u64 img_offset;
	u64 length;
	struct page **pages = NULL;
	u32 page_count;
	int result;

	rbd_assert(rbd_dev->parent != NULL);

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

A
Alex Elder 已提交
2771 2772 2773 2774 2775 2776 2777 2778 2779 2780
	/*
	 * 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;
	}

2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793
	/*
	 * 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;
2794 2795
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2796 2797 2798 2799 2800 2801
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
2802

2803
	parent_request->copyup_pages = pages;
2804
	parent_request->copyup_page_count = page_count;
2805
	parent_request->callback = rbd_img_obj_parent_read_full_callback;
2806

2807 2808 2809 2810 2811
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2812
	parent_request->copyup_page_count = 0;
2813 2814 2815 2816 2817 2818 2819 2820 2821 2822
	parent_request->obj_request = NULL;
	rbd_obj_request_put(obj_request);
out_err:
	if (pages)
		ceph_release_page_vector(pages, page_count);
	if (parent_request)
		rbd_img_request_put(parent_request);
	return result;
}

2823 2824 2825
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2826
	struct rbd_device *rbd_dev;
2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837
	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;
2838
	rbd_obj_request_put(orig_request);
2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849
	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);

2850 2851
	/*
	 * If the overlap has become 0 (most likely because the
2852 2853
	 * image has been flattened) we need to re-submit the
	 * original request.
2854 2855 2856
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2857 2858
		rbd_obj_request_submit(orig_request);
		return;
2859
	}
2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870

	/*
	 * 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);
2871 2872
	} else {
		goto fail_orig_request;
2873 2874 2875 2876 2877 2878
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2879 2880 2881 2882 2883 2884 2885 2886 2887
	result = rbd_img_obj_request_submit(orig_request);
	if (result)
		goto fail_orig_request;

	return;

fail_orig_request:
	orig_request->result = result;
	orig_request->xferred = 0;
2888
	rbd_img_request_get(orig_request->img_request);
2889 2890
	obj_request_done_set(orig_request);
	rbd_obj_request_complete(orig_request);
2891 2892 2893 2894
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
2895
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
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
	struct rbd_obj_request *stat_request;
	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;

G
Guangliang Zhao 已提交
2927
	stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
2928
						   stat_request);
2929 2930 2931 2932
	if (!stat_request->osd_req)
		goto out;
	stat_request->callback = rbd_img_obj_exists_callback;

2933
	osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
2934 2935
	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
					false, false);
2936
	rbd_osd_req_format_read(stat_request);
2937

2938 2939 2940
	rbd_obj_request_submit(stat_request);
	return 0;

2941 2942 2943 2944 2945 2946 2947
out:
	if (ret)
		rbd_obj_request_put(obj_request);

	return ret;
}

2948
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2949
{
2950 2951
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
2952

2953
	/* Reads */
2954 2955
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2956 2957 2958 2959 2960 2961
		return true;

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

2962
	/*
2963 2964
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2965
	 */
2966 2967
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2968

2969 2970 2971 2972 2973 2974 2975 2976
	/*
	 * 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;

2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989
	/*
	 * 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)
{
2990 2991 2992 2993
	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request_type_valid(obj_request->type));
	rbd_assert(obj_request->img_request);

2994
	if (img_obj_request_simple(obj_request)) {
2995 2996
		rbd_obj_request_submit(obj_request);
		return 0;
2997 2998 2999
	}

	/*
3000 3001 3002 3003
	 * 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.
3004
	 */
3005
	if (obj_request_known_test(obj_request))
3006 3007 3008
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
3009 3010 3011 3012

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
3013 3014 3015
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
3016
	struct rbd_obj_request *next_obj_request;
3017
	int ret = 0;
A
Alex Elder 已提交
3018

A
Alex Elder 已提交
3019
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
3020

3021 3022
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
3023
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
3024
		if (ret)
3025
			goto out_put_ireq;
A
Alex Elder 已提交
3026 3027
	}

3028 3029 3030
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
3031
}
A
Alex Elder 已提交
3032 3033 3034 3035

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
3036 3037
	struct rbd_device *rbd_dev;
	u64 obj_end;
3038 3039
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
3040 3041 3042

	rbd_assert(img_request_child_test(img_request));

3043 3044
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
3045
	obj_request = img_request->obj_request;
3046 3047 3048 3049 3050 3051 3052 3053 3054
	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
3055 3056
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
3057 3058
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
3059 3060
		rbd_obj_request_submit(obj_request);
		return;
3061
	}
A
Alex Elder 已提交
3062

3063
	obj_request->result = img_result;
A
Alex Elder 已提交
3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081
	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
3082

3083
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
3084
	} else {
3085
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
3086 3087
	}
out:
A
Alex Elder 已提交
3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099
	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);
3100
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3101 3102

	/* rbd_read_finish(obj_request, obj_request->length); */
3103
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
3104
						obj_request->img_offset,
3105
						obj_request->length);
A
Alex Elder 已提交
3106 3107 3108 3109
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

3110 3111 3112 3113 3114 3115
	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
3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131
	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
3132

3133 3134 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
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
3200
{
3201
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3202
	char cookie[32];
3203
	int ret;
A
Alex Elder 已提交
3204

3205 3206 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
	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;
3278

3279 3280 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
	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);
3577
	/*
3578
	 * Ensure that all in-flight IO is flushed.
3579
	 *
3580 3581
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3582
	 */
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	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
3730

3731 3732
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3733
				   buf, buf_size);
3734
	if (ret)
3735 3736 3737 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
		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
3817 3818
}

3819 3820
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3821
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3822
{
3823
	struct rbd_device *rbd_dev = arg;
3824

3825
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3826

3827 3828 3829 3830
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3831 3832 3833 3834
	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;
3835

3836
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3837
	}
3838
	mutex_unlock(&rbd_dev->watch_mutex);
3839 3840
}

3841
/*
3842
 * watch_mutex must be locked
3843
 */
3844
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3845 3846
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3847
	struct ceph_osd_linger_request *handle;
3848

3849
	rbd_assert(!rbd_dev->watch_handle);
3850
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3851

3852 3853 3854 3855 3856
	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);
3857

3858
	rbd_dev->watch_handle = handle;
3859 3860 3861
	return 0;
}

3862 3863 3864 3865
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3866
{
3867 3868
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3869

3870 3871
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3872

3873 3874 3875
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3876

3877
	rbd_dev->watch_handle = NULL;
3878 3879
}

3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898
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)
3899
{
3900 3901 3902
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3903 3904 3905 3906
	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);
3907 3908 3909 3910
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3911
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3912 3913 3914 3915 3916 3917 3918
	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
3919 3920

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3921 3922
}

3923 3924 3925 3926
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);
3927
	bool was_lock_owner = false;
3928 3929 3930 3931
	int ret;

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

3932 3933 3934 3935
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		was_lock_owner = rbd_release_lock(rbd_dev);

3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957
	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);

3958 3959 3960 3961 3962 3963 3964 3965 3966
	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);
3967 3968 3969 3970
	return;

fail_unlock:
	mutex_unlock(&rbd_dev->watch_mutex);
3971
	up_write(&rbd_dev->lock_rwsem);
3972 3973
}

3974
/*
3975 3976
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3977 3978 3979 3980 3981
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
			     const char *object_name,
			     const char *class_name,
			     const char *method_name,
3982
			     const void *outbound,
3983
			     size_t outbound_size,
3984
			     void *inbound,
3985
			     size_t inbound_size)
3986 3987 3988 3989 3990 3991 3992
{
	struct rbd_obj_request *obj_request;
	struct page **pages;
	u32 page_count;
	int ret;

	/*
3993 3994 3995 3996 3997
	 * 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.
3998
	 */
3999
	page_count = (u32)calc_pages_for(0, inbound_size);
4000 4001 4002 4003 4004
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	ret = -ENOMEM;
4005
	obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
4006 4007 4008 4009 4010 4011 4012
							OBJ_REQUEST_PAGES);
	if (!obj_request)
		goto out;

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

G
Guangliang Zhao 已提交
4013
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4014
						  obj_request);
4015 4016 4017
	if (!obj_request->osd_req)
		goto out;

4018
	osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031
					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);
	}
4032 4033
	osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
					obj_request->pages, inbound_size,
4034
					0, false, false);
4035
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
4036

4037
	rbd_obj_request_submit(obj_request);
4038 4039 4040 4041 4042 4043 4044
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
4045 4046 4047

	rbd_assert(obj_request->xferred < (u64)INT_MAX);
	ret = (int)obj_request->xferred;
4048
	ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
4049 4050 4051 4052 4053 4054 4055 4056 4057
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080
/*
 * 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
4081
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
4082
{
C
Christoph Hellwig 已提交
4083 4084
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
4085
	struct rbd_img_request *img_request;
4086
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
4087 4088
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
4089
	enum obj_operation_type op_type;
4090
	u64 mapping_size;
I
Ilya Dryomov 已提交
4091
	bool must_be_locked;
A
Alex Elder 已提交
4092 4093
	int result;

C
Christoph Hellwig 已提交
4094 4095 4096 4097 4098 4099 4100
	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
4101
	if (req_op(rq) == REQ_OP_DISCARD)
4102
		op_type = OBJ_OP_DISCARD;
M
Mike Christie 已提交
4103
	else if (req_op(rq) == REQ_OP_WRITE)
G
Guangliang Zhao 已提交
4104 4105 4106 4107
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
4108
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4109

I
Ilya Dryomov 已提交
4110 4111 4112 4113 4114
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4115

G
Guangliang Zhao 已提交
4116
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
4117

G
Guangliang Zhao 已提交
4118
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
4119 4120 4121
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
4122
		}
I
Ilya Dryomov 已提交
4123 4124
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
4125

I
Ilya Dryomov 已提交
4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137
	/*
	 * 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
4138

I
Ilya Dryomov 已提交
4139 4140 4141 4142 4143 4144
	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
4145

C
Christoph Hellwig 已提交
4146 4147
	blk_mq_start_request(rq);

4148 4149
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4150
	if (op_type != OBJ_OP_READ) {
4151 4152
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
4153
		must_be_locked = rbd_is_lock_supported(rbd_dev);
I
Ilya Dryomov 已提交
4154 4155 4156
	} else {
		must_be_locked = rbd_dev->opts->lock_on_read &&
					rbd_is_lock_supported(rbd_dev);
4157 4158 4159 4160
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4161
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4162
			 length, mapping_size);
I
Ilya Dryomov 已提交
4163 4164 4165
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4166

4167 4168 4169 4170 4171 4172
	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
4173
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4174
					     snapc);
I
Ilya Dryomov 已提交
4175 4176
	if (!img_request) {
		result = -ENOMEM;
4177
		goto err_unlock;
I
Ilya Dryomov 已提交
4178 4179
	}
	img_request->rq = rq;
4180
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4181

4182 4183 4184 4185 4186 4187
	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
4188 4189
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4190

I
Ilya Dryomov 已提交
4191 4192 4193
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4194

4195 4196
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4197
	return;
A
Alex Elder 已提交
4198

I
Ilya Dryomov 已提交
4199 4200
err_img_request:
	rbd_img_request_put(img_request);
4201 4202 4203
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4204 4205 4206
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4207
			 obj_op_name(op_type), length, offset, result);
4208
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4209 4210
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
4211
}
A
Alex Elder 已提交
4212

C
Christoph Hellwig 已提交
4213 4214
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4215
{
C
Christoph Hellwig 已提交
4216 4217
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4218

C
Christoph Hellwig 已提交
4219 4220
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
4221 4222
}

4223 4224 4225 4226 4227 4228 4229
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

4230 4231
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
4232
		del_gendisk(disk);
4233 4234
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
4235
		blk_mq_free_tag_set(&rbd_dev->tag_set);
4236
	}
4237 4238 4239
	put_disk(disk);
}

4240 4241
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
				const char *object_name,
4242
				u64 offset, u64 length, void *buf)
4243 4244 4245 4246 4247

{
	struct rbd_obj_request *obj_request;
	struct page **pages = NULL;
	u32 page_count;
4248
	size_t size;
4249 4250 4251 4252 4253
	int ret;

	page_count = (u32) calc_pages_for(offset, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
4254
		return PTR_ERR(pages);
4255 4256 4257

	ret = -ENOMEM;
	obj_request = rbd_obj_request_create(object_name, offset, length,
4258
							OBJ_REQUEST_PAGES);
4259 4260 4261 4262 4263 4264
	if (!obj_request)
		goto out;

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

G
Guangliang Zhao 已提交
4265
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4266
						  obj_request);
4267 4268 4269
	if (!obj_request->osd_req)
		goto out;

4270 4271
	osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
					offset, length, 0, 0);
4272
	osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
4273
					obj_request->pages,
4274 4275 4276
					obj_request->length,
					obj_request->offset & ~PAGE_MASK,
					false, false);
4277
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
4278

4279
	rbd_obj_request_submit(obj_request);
4280 4281 4282 4283 4284 4285 4286
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
4287 4288 4289

	rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
	size = (size_t) obj_request->xferred;
4290
	ceph_copy_from_page_vector(pages, buf, 0, size);
4291 4292
	rbd_assert(size <= (size_t)INT_MAX);
	ret = (int)size;
4293 4294 4295 4296 4297 4298 4299 4300 4301
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

4302
/*
A
Alex Elder 已提交
4303 4304 4305
 * 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.
4306
 */
4307
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4308
{
4309
	struct rbd_image_header_ondisk *ondisk = NULL;
4310
	u32 snap_count = 0;
4311 4312 4313
	u64 names_size = 0;
	u32 want_count;
	int ret;
4314

A
Alex Elder 已提交
4315
	/*
4316 4317 4318 4319 4320
	 * 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
4321
	 */
4322 4323 4324 4325 4326 4327 4328 4329 4330 4331
	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
4332
			return -ENOMEM;
4333

4334
		ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_oid.name,
4335
				       0, size, ondisk);
4336
		if (ret < 0)
A
Alex Elder 已提交
4337
			goto out;
A
Alex Elder 已提交
4338
		if ((size_t)ret < size) {
4339
			ret = -ENXIO;
A
Alex Elder 已提交
4340 4341
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4342
			goto out;
4343 4344 4345
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4346
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4347
			goto out;
4348
		}
4349

4350 4351 4352 4353
		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
4354

A
Alex Elder 已提交
4355 4356
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4357 4358 4359
	kfree(ondisk);

	return ret;
4360 4361
}

4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380
/*
 * 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);
}

4381 4382 4383 4384 4385
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4386 4387 4388
	 * 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.
4389
	 */
I
Ilya Dryomov 已提交
4390 4391
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4392 4393 4394 4395 4396 4397 4398
		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
4399
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4400
{
4401
	u64 mapping_size;
A
Alex Elder 已提交
4402 4403
	int ret;

4404
	down_write(&rbd_dev->header_rwsem);
4405
	mapping_size = rbd_dev->mapping.size;
4406 4407

	ret = rbd_dev_header_info(rbd_dev);
4408
	if (ret)
4409
		goto out;
4410

4411 4412 4413 4414 4415 4416 4417
	/*
	 * 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)
4418
			goto out;
4419 4420
	}

4421
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4422
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4423 4424 4425 4426
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4427

4428
out:
4429
	up_write(&rbd_dev->header_rwsem);
4430
	if (!ret && mapping_size != rbd_dev->mapping.size)
4431
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4432

4433
	return ret;
A
Alex Elder 已提交
4434 4435
}

C
Christoph Hellwig 已提交
4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451
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,
};

4452 4453 4454 4455
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4456
	u64 segment_size;
C
Christoph Hellwig 已提交
4457
	int err;
4458 4459

	/* create gendisk info */
4460 4461 4462
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4463
	if (!disk)
A
Alex Elder 已提交
4464
		return -ENOMEM;
4465

A
Alex Elder 已提交
4466
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4467
		 rbd_dev->dev_id);
4468
	disk->major = rbd_dev->major;
4469
	disk->first_minor = rbd_dev->minor;
4470 4471
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4472 4473 4474
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4475 4476
	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
4477
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4478
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4479
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4480 4481 4482 4483 4484
	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)
4485
		goto out_disk;
4486

C
Christoph Hellwig 已提交
4487 4488 4489 4490 4491 4492
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4493 4494
	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
4495

4496
	/* set io sizes to object size */
A
Alex Elder 已提交
4497 4498
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4499
	q->limits.max_sectors = queue_max_hw_sectors(q);
I
Ilya Dryomov 已提交
4500
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
4501 4502 4503
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4504

4505 4506 4507 4508
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
4509
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4510
	q->limits.discard_zeroes_data = 1;
4511

4512 4513 4514
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
		q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

4515 4516 4517 4518 4519 4520 4521
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4522 4523
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4524 4525
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4526
	return err;
4527 4528
}

4529 4530 4531 4532
/*
  sysfs
*/

A
Alex Elder 已提交
4533 4534 4535 4536 4537
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4538 4539 4540
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4541
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4542

A
Alex Elder 已提交
4543 4544
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4545 4546
}

A
Alex Elder 已提交
4547 4548 4549 4550 4551 4552 4553 4554 4555 4556
/*
 * 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
4557
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4558 4559
}

4560 4561 4562
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4563
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4564

A
Alex Elder 已提交
4565 4566 4567 4568
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4569 4570 4571 4572 4573 4574
}

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
4575

4576
	return sprintf(buf, "%d\n", rbd_dev->minor);
4577 4578
}

4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589
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));
}

4590 4591
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4592
{
A
Alex Elder 已提交
4593
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4594

4595
	return sprintf(buf, "client%lld\n",
4596
		       ceph_client_gid(rbd_dev->rbd_client->client));
4597 4598
}

4599 4600 4601 4602 4603 4604 4605 4606
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);
}

4607 4608 4609 4610 4611 4612 4613 4614
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);
}

4615 4616
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4617
{
A
Alex Elder 已提交
4618
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4619

4620
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4621 4622
}

4623 4624 4625 4626 4627
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);

4628
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4629
			(unsigned long long) rbd_dev->spec->pool_id);
4630 4631
}

4632 4633 4634
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4635
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4636

A
Alex Elder 已提交
4637 4638 4639 4640
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4641 4642
}

A
Alex Elder 已提交
4643 4644 4645 4646 4647
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);

4648
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4649 4650
}

A
Alex Elder 已提交
4651 4652 4653 4654
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4655 4656 4657 4658
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4659
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4660

4661
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4662 4663
}

4664 4665 4666 4667 4668 4669 4670 4671
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);
}

4672
/*
4673 4674 4675
 * 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)".
4676 4677
 */
static ssize_t rbd_parent_show(struct device *dev,
4678 4679
			       struct device_attribute *attr,
			       char *buf)
4680 4681
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4682
	ssize_t count = 0;
4683

4684
	if (!rbd_dev->parent)
4685 4686
		return sprintf(buf, "(no parent image)\n");

4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702
	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;
4703 4704
}

4705 4706 4707 4708 4709
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
4710
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4711
	int ret;
4712

A
Alex Elder 已提交
4713
	ret = rbd_dev_refresh(rbd_dev);
4714
	if (ret)
4715
		return ret;
4716

4717
	return size;
4718
}
4719

4720
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4721
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4722
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4723
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4724
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4725
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4726
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4727
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4728
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4729
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4730
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4731
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4732 4733
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4734
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4735
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4736 4737 4738

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4739
	&dev_attr_features.attr,
4740
	&dev_attr_major.attr,
4741
	&dev_attr_minor.attr,
4742
	&dev_attr_client_addr.attr,
4743
	&dev_attr_client_id.attr,
4744
	&dev_attr_cluster_fsid.attr,
4745
	&dev_attr_config_info.attr,
4746
	&dev_attr_pool.attr,
4747
	&dev_attr_pool_id.attr,
4748
	&dev_attr_name.attr,
A
Alex Elder 已提交
4749
	&dev_attr_image_id.attr,
4750
	&dev_attr_current_snap.attr,
4751
	&dev_attr_snap_id.attr,
4752
	&dev_attr_parent.attr,
4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765
	&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
};

4766
static void rbd_dev_release(struct device *dev);
4767 4768 4769 4770

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4771
	.release	= rbd_dev_release,
4772 4773
};

4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794
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;
4795 4796 4797

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813
	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);
}

4814
static void rbd_dev_free(struct rbd_device *rbd_dev)
4815
{
4816
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4817
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4818

4819
	ceph_oid_destroy(&rbd_dev->header_oid);
4820
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4821
	kfree(rbd_dev->config_info);
4822

4823 4824 4825 4826
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839
}

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);
4840 4841 4842 4843 4844 4845 4846 4847 4848 4849

	/*
	 * 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);
}

4850 4851
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4852 4853 4854
{
	struct rbd_device *rbd_dev;

4855
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4856 4857 4858 4859 4860 4861 4862
	if (!rbd_dev)
		return NULL;

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

4863
	ceph_oid_init(&rbd_dev->header_oid);
4864
	ceph_oloc_init(&rbd_dev->header_oloc);
4865

4866 4867 4868 4869
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4870 4871 4872 4873 4874 4875 4876 4877
	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);

4878 4879 4880 4881 4882
	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);

4883
	rbd_dev->rbd_client = rbdc;
4884
	rbd_dev->spec = spec;
4885

4886 4887 4888 4889
	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;
4890
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
4891

4892 4893 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
	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;
4922

4923 4924 4925 4926
	/* 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);
4927
	return rbd_dev;
4928 4929 4930 4931 4932 4933

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4934 4935 4936 4937
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4938 4939
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4940 4941
}

4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956
/*
 * 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 };

4957
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4958
				"rbd", "get_size",
4959
				&snapid, sizeof (snapid),
4960
				&size_buf, sizeof (size_buf));
4961
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4962 4963
	if (ret < 0)
		return ret;
4964 4965
	if (ret < sizeof (size_buf))
		return -ERANGE;
4966

J
Josh Durgin 已提交
4967
	if (order) {
4968
		*order = size_buf.order;
J
Josh Durgin 已提交
4969 4970
		dout("  order %u", (unsigned int)*order);
	}
4971 4972
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4973 4974
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4975
		(unsigned long long)*snap_size);
4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986

	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);
}

4987 4988 4989 4990 4991 4992 4993 4994 4995 4996
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;

4997
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4998
				"rbd", "get_object_prefix", NULL, 0,
4999
				reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
5000
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5001 5002 5003 5004 5005
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5006 5007
						p + ret, NULL, GFP_NOIO);
	ret = 0;
5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020

	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;
}

5021 5022 5023 5024 5025 5026 5027
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;
5028
	} __attribute__ ((packed)) features_buf = { 0 };
5029
	u64 unsup;
5030 5031
	int ret;

5032
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5033
				"rbd", "get_features",
5034
				&snapid, sizeof (snapid),
5035
				&features_buf, sizeof (features_buf));
5036
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5037 5038
	if (ret < 0)
		return ret;
5039 5040
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
5041

5042 5043 5044 5045
	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
5046
		return -ENXIO;
5047
	}
A
Alex Elder 已提交
5048

5049 5050 5051
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5052 5053 5054
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
5055 5056 5057 5058 5059 5060 5061 5062 5063 5064

	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);
}

5065 5066 5067 5068 5069 5070 5071 5072
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
5073
	u64 pool_id;
5074
	char *image_id;
5075
	u64 snap_id;
5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092
	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;
	}

5093
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5094
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5095
				"rbd", "get_parent",
5096
				&snapid, sizeof (snapid),
5097
				reply_buf, size);
5098
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5099 5100 5101 5102
	if (ret < 0)
		goto out_err;

	p = reply_buf;
5103 5104
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
5105
	ceph_decode_64_safe(&p, end, pool_id, out_err);
5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122
	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);
		}

5123
		goto out;	/* No parent?  No problem. */
5124
	}
5125

5126 5127 5128
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5129
	if (pool_id > (u64)U32_MAX) {
5130
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5131
			(unsigned long long)pool_id, U32_MAX);
5132
		goto out_err;
A
Alex Elder 已提交
5133
	}
5134

A
Alex Elder 已提交
5135
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5136 5137 5138 5139
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5140
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5141 5142
	ceph_decode_64_safe(&p, end, overlap, out_err);

5143 5144 5145 5146 5147 5148 5149 5150 5151
	/*
	 * 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
5152 5153
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5154 5155
	} else {
		kfree(image_id);
5156 5157 5158
	}

	/*
5159 5160
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5161 5162 5163
	 */
	if (!overlap) {
		if (parent_spec) {
5164 5165 5166 5167
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5168
		} else {
5169 5170
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5171
		}
A
Alex Elder 已提交
5172
	}
5173 5174
	rbd_dev->parent_overlap = overlap;

5175 5176 5177 5178 5179 5180 5181 5182 5183
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196
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;

5197
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5198
				"rbd", "get_stripe_unit_count", NULL, 0,
5199
				(char *)&striping_info_buf, size);
5200 5201 5202 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
	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;
	}
5228 5229
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5230 5231 5232 5233

	return 0;
}

5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247
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
5248 5249
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5250 5251 5252 5253 5254
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5255
	end = image_id + image_id_size;
5256
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5257 5258 5259 5260 5261 5262

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

5263
	ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
5264 5265
				"rbd", "dir_get_name",
				image_id, image_id_size,
5266
				reply_buf, size);
5267 5268 5269
	if (ret < 0)
		goto out;
	p = reply_buf;
5270 5271
	end = reply_buf + ret;

5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283
	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;
}

5284 5285 5286 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
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);
5314 5315 5316 5317 5318 5319 5320
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5321 5322 5323 5324 5325 5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337 5338
		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);
}

5339
/*
5340 5341 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
 * 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.
5367
 *
5368 5369
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5370
 */
5371
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5372
{
5373 5374 5375 5376 5377
	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;
5378 5379
	int ret;

5380 5381 5382
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5383

5384
	/* Get the pool name; we have to make our own copy of this */
5385

5386 5387 5388
	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);
5389 5390
		return -EIO;
	}
5391 5392
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5393 5394 5395 5396
		return -ENOMEM;

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

5397 5398
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5399
		rbd_warn(rbd_dev, "unable to get image name");
5400

5401
	/* Fetch the snapshot name */
5402

5403
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5404 5405
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5406
		goto out_err;
5407 5408 5409 5410 5411
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5412 5413

	return 0;
5414

5415
out_err:
5416 5417
	kfree(image_name);
	kfree(pool_name);
5418 5419 5420
	return ret;
}

A
Alex Elder 已提交
5421
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444
{
	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;

5445
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5446
				"rbd", "get_snapcontext", NULL, 0,
5447
				reply_buf, size);
5448
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5449 5450 5451 5452
	if (ret < 0)
		goto out;

	p = reply_buf;
5453 5454
	end = reply_buf + ret;
	ret = -ERANGE;
5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470
	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;
5471
	ret = 0;
5472

5473
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5474 5475 5476 5477 5478 5479 5480 5481
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5482
	ceph_put_snap_context(rbd_dev->header.snapc);
5483 5484 5485
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5486
		(unsigned long long)seq, (unsigned int)snap_count);
5487 5488 5489
out:
	kfree(reply_buf);

5490
	return ret;
5491 5492
}

5493 5494
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5495 5496 5497
{
	size_t size;
	void *reply_buf;
5498
	__le64 snapid;
A
Alex Elder 已提交
5499 5500 5501 5502 5503 5504 5505 5506 5507 5508
	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);

5509
	snapid = cpu_to_le64(snap_id);
5510
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
A
Alex Elder 已提交
5511
				"rbd", "get_snapshot_name",
5512
				&snapid, sizeof (snapid),
5513
				reply_buf, size);
5514
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5515 5516
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5517
		goto out;
5518
	}
A
Alex Elder 已提交
5519 5520

	p = reply_buf;
5521
	end = reply_buf + ret;
A
Alex Elder 已提交
5522
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5523
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5524 5525
		goto out;

5526
	dout("  snap_id 0x%016llx snap_name = %s\n",
5527
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5528 5529 5530
out:
	kfree(reply_buf);

5531
	return snap_name;
A
Alex Elder 已提交
5532 5533
}

5534
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5535
{
5536
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5537 5538
	int ret;

5539 5540
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5541
		return ret;
5542

5543 5544 5545
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5546
			return ret;
5547 5548
	}

A
Alex Elder 已提交
5549
	ret = rbd_dev_v2_snap_context(rbd_dev);
5550 5551 5552 5553
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5554 5555 5556 5557

	return ret;
}

5558 5559 5560 5561 5562 5563 5564 5565 5566 5567
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);
}

5568 5569 5570
/*
 * 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
5571 5572
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586
 */
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
5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608
/*
 * 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
5609
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5621
/*
5622 5623 5624 5625
 * 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
5626
 *
5627 5628 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
 * 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.
5661
 */
5662
static int rbd_add_parse_args(const char *buf,
5663
				struct ceph_options **ceph_opts,
5664 5665
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5666
{
A
Alex Elder 已提交
5667
	size_t len;
5668
	char *options;
5669
	const char *mon_addrs;
5670
	char *snap_name;
5671
	size_t mon_addrs_size;
5672
	struct rbd_spec *spec = NULL;
5673
	struct rbd_options *rbd_opts = NULL;
5674
	struct ceph_options *copts;
5675
	int ret;
5676 5677 5678

	/* The first four tokens are required */

5679
	len = next_token(&buf);
5680 5681 5682 5683
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5684
	mon_addrs = buf;
5685
	mon_addrs_size = len + 1;
5686
	buf += len;
5687

5688
	ret = -EINVAL;
5689 5690
	options = dup_token(&buf, NULL);
	if (!options)
5691
		return -ENOMEM;
5692 5693 5694 5695
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5696

5697 5698
	spec = rbd_spec_alloc();
	if (!spec)
5699
		goto out_mem;
5700 5701 5702 5703

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5704 5705 5706 5707
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5708

A
Alex Elder 已提交
5709
	spec->image_name = dup_token(&buf, NULL);
5710
	if (!spec->image_name)
5711
		goto out_mem;
5712 5713 5714 5715
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5716

5717 5718 5719 5720
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5721
	len = next_token(&buf);
5722
	if (!len) {
5723 5724
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5725
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5726
		ret = -ENAMETOOLONG;
5727
		goto out_err;
5728
	}
5729 5730
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5731
		goto out_mem;
5732 5733
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5734

5735
	/* Initialize all rbd options to the defaults */
5736

5737 5738 5739 5740 5741
	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
5742
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5743
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
A
Alex Elder 已提交
5744

5745
	copts = ceph_parse_options(options, mon_addrs,
5746
					mon_addrs + mon_addrs_size - 1,
5747
					parse_rbd_opts_token, rbd_opts);
5748 5749
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5750 5751
		goto out_err;
	}
5752 5753 5754
	kfree(options);

	*ceph_opts = copts;
5755
	*opts = rbd_opts;
5756
	*rbd_spec = spec;
5757

5758
	return 0;
5759
out_mem:
5760
	ret = -ENOMEM;
A
Alex Elder 已提交
5761
out_err:
5762 5763
	kfree(rbd_opts);
	rbd_spec_put(spec);
5764
	kfree(options);
A
Alex Elder 已提交
5765

5766
	return ret;
5767 5768
}

5769 5770 5771 5772 5773
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5774
	struct ceph_options *opts = rbdc->client->options;
5775 5776 5777 5778 5779 5780 5781
	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) {
5782 5783
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5784 5785 5786 5787
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5788
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5789
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5790 5791
						     newest_epoch,
						     opts->mount_timeout);
5792 5793 5794 5795 5796 5797 5798 5799 5800 5801
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5802 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819 5820 5821
/*
 * 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;
5822
	char *image_id;
5823

A
Alex Elder 已提交
5824 5825 5826
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5827 5828
	 * 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
5829
	 */
5830 5831 5832
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5833
		return 0;
5834
	}
A
Alex Elder 已提交
5835

A
Alex Elder 已提交
5836 5837 5838 5839
	/*
	 * 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
5840
	size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
A
Alex Elder 已提交
5841 5842 5843
	object_name = kmalloc(size, GFP_NOIO);
	if (!object_name)
		return -ENOMEM;
5844
	sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
A
Alex Elder 已提交
5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855
	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;
	}

5856 5857
	/* If it doesn't exist we'll assume it's a format 1 image */

5858
	ret = rbd_obj_method_sync(rbd_dev, object_name,
5859
				"rbd", "get_id", NULL, 0,
5860
				response, RBD_IMAGE_ID_LEN_MAX);
5861
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5862 5863 5864 5865 5866
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5867
	} else if (ret >= 0) {
5868 5869 5870
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5871
						NULL, GFP_NOIO);
5872
		ret = PTR_ERR_OR_ZERO(image_id);
5873 5874 5875 5876 5877 5878 5879
		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
5880 5881 5882 5883 5884 5885 5886 5887
	}
out:
	kfree(response);
	kfree(object_name);

	return ret;
}

A
Alex Elder 已提交
5888 5889 5890 5891
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5892 5893 5894 5895
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5896
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5897 5898 5899 5900

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

	header = &rbd_dev->header;
5901
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5902 5903 5904 5905 5906 5907
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5908
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5909 5910 5911
{
	int ret;

5912
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5913
	if (ret)
5914 5915
		goto out_err;

5916 5917 5918 5919
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5920
	ret = rbd_dev_v2_features(rbd_dev);
5921
	if (ret)
5922
		goto out_err;
5923

5924 5925 5926 5927 5928 5929 5930
	/* 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;
	}
5931
	/* No support for crypto and compression type format 2 images */
5932

A
Alex Elder 已提交
5933
	return 0;
5934
out_err:
A
Alex Elder 已提交
5935
	rbd_dev->header.features = 0;
5936 5937
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5938 5939

	return ret;
5940 5941
}

5942 5943 5944 5945 5946 5947
/*
 * @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
5948
{
5949
	struct rbd_device *parent = NULL;
5950 5951 5952 5953 5954
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5955 5956 5957 5958 5959 5960
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5961
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5962 5963
	if (!parent) {
		ret = -ENOMEM;
5964
		goto out_err;
5965 5966 5967 5968 5969 5970 5971 5972
	}

	/*
	 * 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);
5973

5974
	ret = rbd_dev_image_probe(parent, depth);
5975 5976
	if (ret < 0)
		goto out_err;
5977

5978
	rbd_dev->parent = parent;
5979
	atomic_set(&rbd_dev->parent_ref, 1);
5980
	return 0;
5981

5982
out_err:
5983
	rbd_dev_unparent(rbd_dev);
5984
	rbd_dev_destroy(parent);
5985 5986 5987
	return ret;
}

I
Ilya Dryomov 已提交
5988 5989 5990 5991
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5992
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5993
{
A
Alex Elder 已提交
5994
	int ret;
A
Alex Elder 已提交
5995

5996
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5997

5998 5999 6000
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
6001
			goto err_out_unlock;
6002 6003 6004 6005 6006 6007 6008

		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
6009 6010 6011 6012 6013 6014 6015

	/* Set up the blkdev mapping. */

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

6016
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
6017 6018
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
6019

6020
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6021
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
6022

6023 6024
	dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
	ret = device_add(&rbd_dev->dev);
6025
	if (ret)
6026
		goto err_out_mapping;
A
Alex Elder 已提交
6027 6028 6029

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

6030
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
6031
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6032

6033 6034 6035 6036
	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
6037
	add_disk(rbd_dev->disk);
6038 6039 6040
	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
6041 6042

	return ret;
6043

6044 6045
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
6046 6047 6048
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
6049 6050
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
6051 6052
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6053 6054 6055
	return ret;
}

A
Alex Elder 已提交
6056 6057 6058
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
6059
	int ret;
A
Alex Elder 已提交
6060 6061 6062 6063 6064

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

	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));

6065
	rbd_dev->header_oloc.pool = rbd_dev->layout.pool_id;
A
Alex Elder 已提交
6066
	if (rbd_dev->image_format == 1)
6067 6068
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
6069
	else
6070 6071
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
6072

6073
	return ret;
A
Alex Elder 已提交
6074 6075
}

6076 6077
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6078 6079 6080 6081 6082
	rbd_dev_unprobe(rbd_dev);
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

6083 6084 6085
	rbd_dev_destroy(rbd_dev);
}

6086 6087
/*
 * Probe for the existence of the header object for the given rbd
6088 6089 6090
 * 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.
6091
 */
6092
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6093 6094 6095 6096
{
	int ret;

	/*
A
Alex Elder 已提交
6097 6098 6099 6100
	 * 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.
6101 6102 6103
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6104 6105
		return ret;

A
Alex Elder 已提交
6106 6107 6108 6109
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6110
	if (!depth) {
6111
		ret = rbd_register_watch(rbd_dev);
6112 6113 6114 6115 6116
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6117
			goto err_out_format;
6118
		}
6119
	}
6120

6121
	ret = rbd_dev_header_info(rbd_dev);
6122
	if (ret)
6123
		goto err_out_watch;
A
Alex Elder 已提交
6124

6125 6126 6127 6128 6129 6130
	/*
	 * 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.
	 */
6131
	if (!depth)
6132 6133 6134
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6135 6136 6137 6138 6139 6140
	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
6141
		goto err_out_probe;
6142
	}
6143

6144 6145 6146 6147 6148 6149 6150 6151 6152
	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.
		 */
6153
		if (!depth && rbd_dev->parent_spec)
6154 6155 6156 6157
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6158
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6159 6160 6161 6162
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6163
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6164
	return 0;
6165

A
Alex Elder 已提交
6166 6167
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6168
err_out_watch:
6169
	if (!depth)
6170
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6171 6172
err_out_format:
	rbd_dev->image_format = 0;
6173 6174
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6175 6176 6177
	return ret;
}

6178 6179 6180
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6181
{
6182
	struct rbd_device *rbd_dev = NULL;
6183
	struct ceph_options *ceph_opts = NULL;
6184
	struct rbd_options *rbd_opts = NULL;
6185
	struct rbd_spec *spec = NULL;
6186
	struct rbd_client *rbdc;
6187
	bool read_only;
6188
	int rc;
6189 6190 6191 6192 6193

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

	/* parse add command */
6194
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6195
	if (rc < 0)
6196
		goto out;
6197

6198 6199 6200
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6201
		goto err_out_args;
6202
	}
6203 6204

	/* pick the pool */
6205
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6206 6207 6208
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6209
		goto err_out_client;
6210
	}
A
Alex Elder 已提交
6211
	spec->pool_id = (u64)rc;
6212

6213
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6214 6215
	if (!rbd_dev) {
		rc = -ENOMEM;
6216
		goto err_out_client;
6217
	}
6218 6219
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6220
	rbd_opts = NULL;	/* rbd_dev now owns this */
6221

6222 6223 6224 6225 6226 6227
	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
6228
	down_write(&rbd_dev->header_rwsem);
6229
	rc = rbd_dev_image_probe(rbd_dev, 0);
6230 6231
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6232
		goto err_out_rbd_dev;
6233
	}
6234

6235 6236
	/* If we are mapping a snapshot it must be marked read-only */

6237
	read_only = rbd_dev->opts->read_only;
6238 6239 6240 6241
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

6242
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
6243
	if (rc) {
6244
		/*
6245
		 * rbd_unregister_watch() can't be moved into
6246 6247 6248
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
6249
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6250
		rbd_dev_image_release(rbd_dev);
6251
		goto out;
A
Alex Elder 已提交
6252 6253
	}

6254 6255 6256 6257
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6258

6259 6260
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6261
err_out_client:
6262
	rbd_put_client(rbdc);
6263
err_out_args:
6264
	rbd_spec_put(spec);
6265
	kfree(rbd_opts);
6266
	goto out;
6267 6268
}

6269 6270 6271 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285
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);
}

6286
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6287 6288
{
	rbd_free_disk(rbd_dev);
6289 6290 6291 6292 6293

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

6294
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6295
	device_del(&rbd_dev->dev);
A
Alex Elder 已提交
6296
	rbd_dev_mapping_clear(rbd_dev);
6297 6298
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
6299 6300
}

6301 6302
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6303
	while (rbd_dev->parent) {
6304 6305 6306 6307 6308 6309 6310 6311 6312 6313 6314 6315
		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
6316
		rbd_assert(second);
6317
		rbd_dev_image_release(second);
A
Alex Elder 已提交
6318 6319 6320 6321
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6322 6323 6324 6325 6326
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6327 6328 6329
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6330 6331
{
	struct rbd_device *rbd_dev = NULL;
6332 6333
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6334
	char opt_buf[6];
6335
	bool already = false;
M
Mike Christie 已提交
6336
	bool force = false;
6337
	int ret;
6338

M
Mike Christie 已提交
6339 6340 6341 6342 6343
	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");
6344
		return -EINVAL;
M
Mike Christie 已提交
6345 6346 6347 6348 6349 6350 6351 6352 6353
	}
	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;
		}
	}
6354

6355 6356 6357 6358 6359 6360 6361 6362
	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;
		}
6363
	}
6364 6365
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6366
		if (rbd_dev->open_count && !force)
6367 6368
			ret = -EBUSY;
		else
6369 6370
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6371 6372 6373
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6374
	if (ret < 0 || already)
6375
		return ret;
6376

M
Mike Christie 已提交
6377 6378 6379 6380 6381 6382 6383 6384 6385
	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);
	}

6386 6387 6388 6389
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
6390
	rbd_unregister_watch(rbd_dev);
6391

6392 6393 6394 6395 6396 6397
	/*
	 * 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.
	 */
6398
	rbd_dev_device_release(rbd_dev);
6399
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
6400

6401
	return count;
6402 6403
}

6404 6405 6406 6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419 6420
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);
}

6421 6422
/*
 * create control files in sysfs
6423
 * /sys/bus/rbd/...
6424 6425 6426
 */
static int rbd_sysfs_init(void)
{
6427
	int ret;
6428

6429
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6430
	if (ret < 0)
6431
		return ret;
6432

6433 6434 6435
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6436 6437 6438 6439 6440 6441

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6442
	bus_unregister(&rbd_bus_type);
6443
	device_unregister(&rbd_root_dev);
6444 6445
}

6446 6447 6448
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6449
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6450 6451 6452 6453
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6454
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6455 6456 6457 6458 6459
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6460
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6461
	if (rbd_segment_name_cache)
6462
		return 0;
6463
out_err:
6464 6465
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6466

6467 6468 6469
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

6470 6471 6472 6473 6474
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6475 6476 6477 6478
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

6479 6480 6481 6482
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6483 6484 6485 6486 6487
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
6488
static int __init rbd_init(void)
6489 6490 6491
{
	int rc;

6492 6493 6494 6495
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6496

6497
	rc = rbd_slab_init();
6498 6499
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6500

6501 6502
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6503
	 * rbd devices * queue depth, so leave @max_active at default.
6504 6505 6506 6507 6508 6509 6510
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6511 6512 6513 6514
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6515
			goto err_out_wq;
6516 6517 6518
		}
	}

6519 6520
	rc = rbd_sysfs_init();
	if (rc)
6521 6522 6523 6524 6525 6526
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6527

I
Ilya Dryomov 已提交
6528 6529
	return 0;

6530 6531 6532
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6533 6534
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6535 6536
err_out_slab:
	rbd_slab_exit();
6537
	return rc;
6538 6539
}

A
Alex Elder 已提交
6540
static void __exit rbd_exit(void)
6541
{
I
Ilya Dryomov 已提交
6542
	ida_destroy(&rbd_dev_id_ida);
6543
	rbd_sysfs_cleanup();
6544 6545
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6546
	destroy_workqueue(rbd_wq);
6547
	rbd_slab_exit();
6548 6549 6550 6551 6552
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6553
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6554 6555 6556 6557 6558
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>");

6559
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6560
MODULE_LICENSE("GPL");