rbd.c 151.1 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		(1ULL<<0)
#define RBD_FEATURE_STRIPINGV2		(1ULL<<1)
#define RBD_FEATURE_EXCLUSIVE_LOCK	(1ULL<<2)
#define RBD_FEATURE_DATA_POOL		(1ULL<<7)
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#define RBD_FEATURE_OPERATIONS		(1ULL<<8)
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#define RBD_FEATURES_ALL	(RBD_FEATURE_LAYERING |		\
				 RBD_FEATURE_STRIPINGV2 |	\
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				 RBD_FEATURE_EXCLUSIVE_LOCK |	\
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				 RBD_FEATURE_DATA_POOL |	\
				 RBD_FEATURE_OPERATIONS)
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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;
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	u64 stripe_unit;
	u64 stripe_count;
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	s64 data_pool_id;
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	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 {
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	OBJ_REQUEST_NODATA = 1,
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	OBJ_REQUEST_BIO,	/* pointer into provided bio (list) */
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	OBJ_REQUEST_BVECS,	/* pointer into provided bio_vec array */
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};
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enum obj_operation_type {
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	OBJ_OP_READ = 1,
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	OBJ_OP_WRITE,
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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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};

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/*
 * Writes go through the following state machine to deal with
 * layering:
 *
 *                       need copyup
 * RBD_OBJ_WRITE_GUARD ---------------> RBD_OBJ_WRITE_COPYUP
 *        |     ^                              |
 *        v     \------------------------------/
 *      done
 *        ^
 *        |
 * RBD_OBJ_WRITE_FLAT
 *
 * Writes start in RBD_OBJ_WRITE_GUARD or _FLAT, depending on whether
 * there is a parent or not.
 */
enum rbd_obj_write_state {
	RBD_OBJ_WRITE_FLAT = 1,
	RBD_OBJ_WRITE_GUARD,
	RBD_OBJ_WRITE_COPYUP,
};

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struct rbd_obj_request {
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	u64			object_no;
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	u64			offset;		/* object start byte */
	u64			length;		/* bytes from offset */
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	unsigned long		flags;
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	union {
		bool			tried_parent;	/* for reads */
		enum rbd_obj_write_state write_state;	/* for writes */
	};
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	/*
	 * An object request associated with an image will have its
	 * img_data flag set; a standalone object request will not.
	 *
	 * 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).
	 */
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	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 {
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		struct ceph_bio_iter	bio_pos;
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		struct {
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			struct ceph_bvec_iter	bvec_pos;
			u32			bvec_count;
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		};
	};
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	struct bio_vec		*copyup_bvecs;
	u32			copyup_bvec_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;

	struct kref		kref;
};

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enum img_req_flags {
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	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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};

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struct rbd_img_request {
	struct rbd_device	*rbd_dev;
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	enum obj_operation_type	op_type;
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	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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	};
	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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};

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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;
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	char			lock_cookie[32];
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	struct rbd_client_id	owner_cid;
	struct work_struct	acquired_lock_work;
	struct work_struct	released_lock_work;
	struct delayed_work	lock_dwork;
	struct work_struct	unlock_work;
	wait_queue_head_t	lock_waitq;

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

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

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

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

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

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static struct kmem_cache	*rbd_img_request_cache;
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static struct kmem_cache	*rbd_obj_request_cache;
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static 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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/*
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 * single-major requires >= 0.75 version of userspace rbd utility.
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 */
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static bool single_major = true;
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module_param(single_major, bool, S_IRUGO);
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MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: true)");
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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_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 ssize_t rbd_supported_features_show(struct bus_type *bus, char *buf)
{
	return sprintf(buf, "0x%llx\n", RBD_FEATURES_SUPPORTED);
}

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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 BUS_ATTR(supported_features, S_IRUGO, rbd_supported_features_show, NULL);
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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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	&bus_attr_supported_features.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_dev_remove_parent(struct rbd_device *rbd_dev);
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598
static int rbd_dev_refresh(struct rbd_device *rbd_dev);
599
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
600
static int rbd_dev_header_info(struct rbd_device *rbd_dev);
601
static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
602 603
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id);
604 605 606 607
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);
608

609 610
static int rbd_open(struct block_device *bdev, fmode_t mode)
{
A
Alex Elder 已提交
611
	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
612
	bool removing = false;
613

614
	spin_lock_irq(&rbd_dev->lock);
615 616 617 618
	if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
		removing = true;
	else
		rbd_dev->open_count++;
619
	spin_unlock_irq(&rbd_dev->lock);
620 621 622
	if (removing)
		return -ENOENT;

A
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623
	(void) get_device(&rbd_dev->dev);
624

625 626 627
	return 0;
}

628
static void rbd_release(struct gendisk *disk, fmode_t mode)
629 630
{
	struct rbd_device *rbd_dev = disk->private_data;
631 632
	unsigned long open_count_before;

633
	spin_lock_irq(&rbd_dev->lock);
634
	open_count_before = rbd_dev->open_count--;
635
	spin_unlock_irq(&rbd_dev->lock);
636
	rbd_assert(open_count_before > 0);
637

A
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638
	put_device(&rbd_dev->dev);
639 640
}

G
Guangliang Zhao 已提交
641 642
static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
643
	int ro;
G
Guangliang Zhao 已提交
644

645
	if (get_user(ro, (int __user *)arg))
G
Guangliang Zhao 已提交
646 647
		return -EFAULT;

648
	/* Snapshots can't be marked read-write */
G
Guangliang Zhao 已提交
649 650 651
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
		return -EROFS;

652 653
	/* Let blkdev_roset() handle it */
	return -ENOTTY;
G
Guangliang Zhao 已提交
654 655 656 657 658 659
}

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;
660
	int ret;
G
Guangliang Zhao 已提交
661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680

	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 */

681 682 683
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
684
	.release		= rbd_release,
G
Guangliang Zhao 已提交
685 686 687 688
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
689 690 691
};

/*
692
 * Initialize an rbd client instance.  Success or not, this function
693
 * consumes ceph_opts.  Caller holds client_mutex.
694
 */
695
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
696 697 698 699
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

A
Alex Elder 已提交
700
	dout("%s:\n", __func__);
701 702 703 704 705 706 707
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

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

708
	rbdc->client = ceph_create_client(ceph_opts, rbdc);
709
	if (IS_ERR(rbdc->client))
710
		goto out_rbdc;
A
Alex Elder 已提交
711
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
712 713 714

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
715
		goto out_client;
716

A
Alex Elder 已提交
717
	spin_lock(&rbd_client_list_lock);
718
	list_add_tail(&rbdc->node, &rbd_client_list);
A
Alex Elder 已提交
719
	spin_unlock(&rbd_client_list_lock);
720

A
Alex Elder 已提交
721
	dout("%s: rbdc %p\n", __func__, rbdc);
722

723
	return rbdc;
724
out_client:
725
	ceph_destroy_client(rbdc->client);
726
out_rbdc:
727 728
	kfree(rbdc);
out_opt:
A
Alex Elder 已提交
729 730
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
A
Alex Elder 已提交
731 732
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
733
	return ERR_PTR(ret);
734 735
}

736 737 738 739 740 741 742
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

743
/*
744 745
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
746
 */
747
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
748 749
{
	struct rbd_client *client_node;
750
	bool found = false;
751

A
Alex Elder 已提交
752
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
753 754
		return NULL;

755 756 757
	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)) {
758 759
			__rbd_get_client(client_node);

760 761 762 763 764 765 766
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
767 768
}

769
/*
770
 * (Per device) rbd map options
771 772
 */
enum {
I
Ilya Dryomov 已提交
773
	Opt_queue_depth,
774 775 776 777
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
A
Alex Elder 已提交
778 779
	Opt_read_only,
	Opt_read_write,
I
Ilya Dryomov 已提交
780
	Opt_lock_on_read,
I
Ilya Dryomov 已提交
781
	Opt_exclusive,
782
	Opt_err
783 784
};

A
Alex Elder 已提交
785
static match_table_t rbd_opts_tokens = {
I
Ilya Dryomov 已提交
786
	{Opt_queue_depth, "queue_depth=%d"},
787 788
	/* int args above */
	/* string args above */
A
Alex Elder 已提交
789
	{Opt_read_only, "read_only"},
A
Alex Elder 已提交
790 791 792
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
I
Ilya Dryomov 已提交
793
	{Opt_lock_on_read, "lock_on_read"},
I
Ilya Dryomov 已提交
794
	{Opt_exclusive, "exclusive"},
795
	{Opt_err, NULL}
796 797
};

A
Alex Elder 已提交
798
struct rbd_options {
I
Ilya Dryomov 已提交
799
	int	queue_depth;
A
Alex Elder 已提交
800
	bool	read_only;
I
Ilya Dryomov 已提交
801
	bool	lock_on_read;
I
Ilya Dryomov 已提交
802
	bool	exclusive;
A
Alex Elder 已提交
803 804
};

I
Ilya Dryomov 已提交
805
#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
A
Alex Elder 已提交
806
#define RBD_READ_ONLY_DEFAULT	false
I
Ilya Dryomov 已提交
807
#define RBD_LOCK_ON_READ_DEFAULT false
I
Ilya Dryomov 已提交
808
#define RBD_EXCLUSIVE_DEFAULT	false
A
Alex Elder 已提交
809

810 811
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
812
	struct rbd_options *rbd_opts = private;
813 814 815
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
Alex Elder 已提交
816
	token = match_token(c, rbd_opts_tokens, argstr);
817 818 819
	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
820
			pr_err("bad mount option arg (not int) at '%s'\n", c);
821 822 823 824
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
825
		dout("got string token %d val %s\n", token, argstr[0].from);
826 827 828 829 830
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
I
Ilya Dryomov 已提交
831 832 833 834 835 836 837
	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
838 839 840 841 842 843
	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
844 845 846
	case Opt_lock_on_read:
		rbd_opts->lock_on_read = true;
		break;
I
Ilya Dryomov 已提交
847 848 849
	case Opt_exclusive:
		rbd_opts->exclusive = true;
		break;
850
	default:
851 852
		/* libceph prints "bad option" msg */
		return -EINVAL;
853
	}
854

855 856 857
	return 0;
}

G
Guangliang Zhao 已提交
858 859 860 861 862 863 864
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";
865 866
	case OBJ_OP_DISCARD:
		return "discard";
G
Guangliang Zhao 已提交
867 868 869 870 871
	default:
		return "???";
	}
}

872 873
/*
 * Get a ceph client with specific addr and configuration, if one does
874 875
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
876
 */
877
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
878
{
879
	struct rbd_client *rbdc;
880

881
	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
882
	rbdc = rbd_client_find(ceph_opts);
883
	if (rbdc)	/* using an existing client */
A
Alex Elder 已提交
884
		ceph_destroy_options(ceph_opts);
885
	else
886
		rbdc = rbd_client_create(ceph_opts);
887
	mutex_unlock(&client_mutex);
888

889
	return rbdc;
890 891 892 893
}

/*
 * Destroy ceph client
A
Alex Elder 已提交
894
 *
A
Alex Elder 已提交
895
 * Caller must hold rbd_client_list_lock.
896 897 898 899 900
 */
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
901
	dout("%s: rbdc %p\n", __func__, rbdc);
902
	spin_lock(&rbd_client_list_lock);
903
	list_del(&rbdc->node);
904
	spin_unlock(&rbd_client_list_lock);
905 906 907 908 909 910 911 912 913

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

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
914
static void rbd_put_client(struct rbd_client *rbdc)
915
{
916 917
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
918 919
}

920 921 922 923 924
static bool rbd_image_format_valid(u32 image_format)
{
	return image_format == 1 || image_format == 2;
}

925 926
static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
{
927 928 929 930 931 932 933
	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
934 935 936 937 938 939 940 941 942 943
	/* 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;

944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961
	/*
	 * 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;
962 963
}

I
Ilya Dryomov 已提交
964 965 966 967 968 969 970 971
/*
 * returns the size of an object in the image
 */
static u32 rbd_obj_bytes(struct rbd_image_header *header)
{
	return 1U << header->obj_order;
}

I
Ilya Dryomov 已提交
972 973 974 975 976 977 978 979 980 981 982
static void rbd_init_layout(struct rbd_device *rbd_dev)
{
	if (rbd_dev->header.stripe_unit == 0 ||
	    rbd_dev->header.stripe_count == 0) {
		rbd_dev->header.stripe_unit = rbd_obj_bytes(&rbd_dev->header);
		rbd_dev->header.stripe_count = 1;
	}

	rbd_dev->layout.stripe_unit = rbd_dev->header.stripe_unit;
	rbd_dev->layout.stripe_count = rbd_dev->header.stripe_count;
	rbd_dev->layout.object_size = rbd_obj_bytes(&rbd_dev->header);
983 984
	rbd_dev->layout.pool_id = rbd_dev->header.data_pool_id == CEPH_NOPOOL ?
			  rbd_dev->spec->pool_id : rbd_dev->header.data_pool_id;
I
Ilya Dryomov 已提交
985 986 987
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
}

988
/*
989 990
 * Fill an rbd image header with information from the given format 1
 * on-disk header.
991
 */
A
Alex Elder 已提交
992
static int rbd_header_from_disk(struct rbd_device *rbd_dev,
993
				 struct rbd_image_header_ondisk *ondisk)
994
{
A
Alex Elder 已提交
995
	struct rbd_image_header *header = &rbd_dev->header;
996 997 998 999 1000
	bool first_time = header->object_prefix == NULL;
	struct ceph_snap_context *snapc;
	char *object_prefix = NULL;
	char *snap_names = NULL;
	u64 *snap_sizes = NULL;
1001
	u32 snap_count;
1002
	int ret = -ENOMEM;
1003
	u32 i;
1004

1005
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
1006

1007
	if (first_time) {
1008 1009 1010
		object_prefix = kstrndup(ondisk->object_prefix,
					 sizeof(ondisk->object_prefix),
					 GFP_KERNEL);
1011 1012 1013
		if (!object_prefix)
			return -ENOMEM;
	}
A
Alex Elder 已提交
1014

1015
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
1016

1017 1018 1019 1020 1021
	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);
1022
	if (snap_count) {
1023
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
1024 1025
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

1026
		/* We'll keep a copy of the snapshot names... */
1027

1028 1029 1030 1031
		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
1032 1033
			goto out_err;

1034
		/* ...as well as the array of their sizes. */
1035 1036 1037
		snap_sizes = kmalloc_array(snap_count,
					   sizeof(*header->snap_sizes),
					   GFP_KERNEL);
1038
		if (!snap_sizes)
A
Alex Elder 已提交
1039
			goto out_err;
1040

A
Alex Elder 已提交
1041
		/*
1042 1043 1044
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
1045
		 * Note that rbd_dev_v1_header_info() guarantees the
1046
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
1047 1048 1049
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
1050 1051 1052 1053 1054 1055
		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);
		}
1056
	}
A
Alex Elder 已提交
1057

1058
	/* We won't fail any more, fill in the header */
1059

1060 1061 1062
	if (first_time) {
		header->object_prefix = object_prefix;
		header->obj_order = ondisk->options.order;
I
Ilya Dryomov 已提交
1063
		rbd_init_layout(rbd_dev);
1064
	} else {
A
Alex Elder 已提交
1065 1066 1067
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
1068
	}
1069

1070
	/* The remaining fields always get updated (when we refresh) */
1071

A
Alex Elder 已提交
1072
	header->image_size = le64_to_cpu(ondisk->image_size);
1073 1074 1075
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1076

1077
	return 0;
1078 1079
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1080
out_err:
1081 1082 1083 1084
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1085

1086
	return ret;
1087 1088
}

1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
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);
}

1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
/*
 * 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.
 */
1128 1129 1130
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1131
	u64 *found;
1132

1133 1134
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1135

1136
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1137 1138
}

1139 1140
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1141
{
1142
	u32 which;
1143
	const char *snap_name;
1144

1145 1146
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1147
		return ERR_PTR(-ENOENT);
1148

1149 1150
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1151 1152 1153 1154
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1155 1156 1157
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1158 1159 1160
	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);
1161

1162
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1163 1164
}

1165 1166
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1167
{
1168 1169 1170 1171 1172
	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;
1173

1174 1175 1176
		which = rbd_dev_snap_index(rbd_dev, snap_id);
		if (which == BAD_SNAP_INDEX)
			return -ENOENT;
1177

1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189
		*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;
1190 1191
}

1192 1193
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1194
{
1195 1196 1197 1198 1199
	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 */
1200
	} else {
1201 1202
		u64 features = 0;
		int ret;
1203

1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
		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)
{
1215
	u64 snap_id = rbd_dev->spec->snap_id;
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229
	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;

1230
	return 0;
1231 1232
}

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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;
1237 1238
}

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static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
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1241
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
1242

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	return offset & (segment_size - 1);
}

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

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	rbd_assert(length <= U64_MAX - offset);
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	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1258 1259
}

1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280
static void zero_bvec(struct bio_vec *bv)
{
	void *buf;
	unsigned long flags;

	buf = bvec_kmap_irq(bv, &flags);
	memset(buf, 0, bv->bv_len);
	flush_dcache_page(bv->bv_page);
	bvec_kunmap_irq(buf, &flags);
}

static void zero_bios(struct ceph_bio_iter *bio_pos, u32 off, u32 bytes)
{
	struct ceph_bio_iter it = *bio_pos;

	ceph_bio_iter_advance(&it, off);
	ceph_bio_iter_advance_step(&it, bytes, ({
		zero_bvec(&bv);
	}));
}

1281 1282 1283 1284 1285 1286 1287 1288
static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes)
{
	struct ceph_bvec_iter it = *bvec_pos;

	ceph_bvec_iter_advance(&it, off);
	ceph_bvec_iter_advance_step(&it, bytes, ({
		zero_bvec(&bv);
	}));
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}

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1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311
/*
 * Zero a range in @obj_req data buffer defined by a bio (list) or
 * bio_vec array.
 *
 * @off is relative to the start of the data buffer.
 */
static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off,
			       u32 bytes)
{
	switch (obj_req->type) {
	case OBJ_REQUEST_BIO:
		zero_bios(&obj_req->bio_pos, off, bytes);
		break;
	case OBJ_REQUEST_BVECS:
		zero_bvecs(&obj_req->bvec_pos, off, bytes);
		break;
	default:
		rbd_assert(0);
	}
}

1312 1313 1314 1315 1316
/*
 * 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.
 */
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static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1318
{
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	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1320 1321
		struct rbd_device *rbd_dev;

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		rbd_dev = obj_request->img_request->rbd_dev;
1323
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1324 1325 1326 1327
			obj_request);
	}
}

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static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1329 1330
{
	smp_mb();
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	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1332 1333
}

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static void obj_request_done_set(struct rbd_obj_request *obj_request)
1335
{
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	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1338

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		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1341
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1342 1343 1344 1345
			obj_request);
	}
}

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static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1347 1348
{
	smp_mb();
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	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1350 1351
}

1352 1353 1354 1355 1356 1357 1358 1359
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));
}

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static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
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	dout("%s: obj %p (was %d)\n", __func__, obj_request,
1363
		kref_read(&obj_request->kref));
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	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);
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	dout("%s: obj %p (was %d)\n", __func__, obj_request,
1372
		kref_read(&obj_request->kref));
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	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1376 1377 1378
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
1379
	     kref_read(&img_request->kref));
1380 1381 1382
	kref_get(&img_request->kref);
}

1383 1384
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
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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);
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	dout("%s: img %p (was %d)\n", __func__, img_request,
1390
		kref_read(&img_request->kref));
1391 1392 1393 1394
	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);
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}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1400 1401
	rbd_assert(obj_request->img_request == NULL);

1402
	/* Image request now owns object's original reference */
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1403
	obj_request->img_request = img_request;
1404
	obj_request->which = img_request->obj_request_count;
1405 1406
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
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	rbd_assert(obj_request->which != BAD_WHICH);
1408 1409
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
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	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
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1412 1413 1414 1415 1416 1417
}

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);
1418

A
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1419 1420
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
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	list_del(&obj_request->links);
1422 1423 1424 1425
	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;
1426
	rbd_assert(obj_request_img_data_test(obj_request));
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	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1429
	obj_request->callback = NULL;
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1430 1431 1432 1433 1434 1435
	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1436
	case OBJ_REQUEST_NODATA:
A
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	case OBJ_REQUEST_BIO:
1438
	case OBJ_REQUEST_BVECS:
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1439 1440 1441 1442 1443 1444
		return true;
	default:
		return false;
	}
}

1445 1446
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

1447
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
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{
1449 1450
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1451 1452
	dout("%s %p object_no %016llx %llu~%llu osd_req %p\n", __func__,
	     obj_request, obj_request->object_no, obj_request->offset,
1453
	     obj_request->length, osd_req);
1454 1455 1456 1457
	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);
	}
1458
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
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1459 1460 1461 1462
}

static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1463

A
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1464
	dout("%s: img %p\n", __func__, img_request);
1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480

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

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

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1481 1482 1483 1484 1485 1486
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
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1487 1488 1489 1490 1491
/*
 * 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.
 */
1492 1493 1494 1495 1496 1497
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1498 1499 1500 1501 1502 1503
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1504 1505 1506 1507 1508 1509
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1510 1511 1512 1513 1514 1515
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1516 1517 1518 1519 1520 1521
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1522 1523 1524 1525 1526 1527
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

I
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1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545
static bool rbd_obj_is_entire(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;

	return !obj_req->offset &&
	       obj_req->length == rbd_dev->layout.object_size;
}

static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;

	return obj_req->offset + obj_req->length ==
					rbd_dev->layout.object_size;
}

static bool rbd_img_is_write(struct rbd_img_request *img_req)
{
I
Ilya Dryomov 已提交
1546
	switch (img_req->op_type) {
I
Ilya Dryomov 已提交
1547 1548 1549 1550 1551 1552 1553 1554 1555 1556
	case OBJ_OP_READ:
		return false;
	case OBJ_OP_WRITE:
	case OBJ_OP_DISCARD:
		return true;
	default:
		rbd_assert(0);
	}
}

A
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1557 1558
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
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1559 1560
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
1561
	obj_request->callback(obj_request);
A
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1562 1563
}

I
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1564 1565
static void rbd_obj_handle_request(struct rbd_obj_request *obj_req);

1566
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
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1567
{
I
Ilya Dryomov 已提交
1568
	struct rbd_obj_request *obj_req = osd_req->r_priv;
A
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1569

I
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1570 1571 1572
	dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req,
	     osd_req->r_result, obj_req);
	rbd_assert(osd_req == obj_req->osd_req);
1573

I
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1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
	obj_req->result = osd_req->r_result < 0 ? osd_req->r_result : 0;
	if (!obj_req->result && !rbd_img_is_write(obj_req->img_request))
		obj_req->xferred = osd_req->r_result;
	else
		/*
		 * Writes aren't allowed to return a data payload.  In some
		 * guarded write cases (e.g. stat + zero on an empty object)
		 * a stat response makes it through, but we don't care.
		 */
		obj_req->xferred = 0;
A
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1584

I
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1585
	rbd_obj_handle_request(obj_req);
A
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1586 1587
}

1588
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
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1589
{
1590
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
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1591

1592
	rbd_assert(obj_request_img_data_test(obj_request));
1593
	osd_req->r_flags = CEPH_OSD_FLAG_READ;
1594
	osd_req->r_snapid = obj_request->img_request->snap_id;
1595 1596 1597 1598 1599 1600
}

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

1601
	osd_req->r_flags = CEPH_OSD_FLAG_WRITE;
1602
	ktime_get_real_ts(&osd_req->r_mtime);
1603
	osd_req->r_data_offset = obj_request->offset;
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1604 1605
}

1606
static struct ceph_osd_request *
1607
rbd_osd_req_create(struct rbd_obj_request *obj_req, unsigned int num_ops)
1608
{
1609 1610
	struct rbd_img_request *img_req = obj_req->img_request;
	struct rbd_device *rbd_dev = img_req->rbd_dev;
1611 1612
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_osd_request *req;
1613 1614
	const char *name_format = rbd_dev->image_format == 1 ?
				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
1615

1616 1617 1618
	req = ceph_osdc_alloc_request(osdc,
			(rbd_img_is_write(img_req) ? img_req->snapc : NULL),
			num_ops, false, GFP_NOIO);
1619 1620 1621 1622
	if (!req)
		return NULL;

	req->r_callback = rbd_osd_req_callback;
1623
	req->r_priv = obj_req;
1624 1625

	req->r_base_oloc.pool = rbd_dev->layout.pool_id;
1626
	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
1627
			rbd_dev->header.object_prefix, obj_req->object_no))
1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639
		goto err_req;

	if (ceph_osdc_alloc_messages(req, GFP_NOIO))
		goto err_req;

	return req;

err_req:
	ceph_osdc_put_request(req);
	return NULL;
}

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1640 1641 1642 1643 1644
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

1645 1646
static struct rbd_obj_request *
rbd_obj_request_create(enum obj_request_type type)
A
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1647 1648 1649 1650 1651
{
	struct rbd_obj_request *obj_request;

	rbd_assert(obj_request_type_valid(type));

1652
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
1653
	if (!obj_request)
1654 1655
		return NULL;

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1656 1657 1658 1659 1660
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
	kref_init(&obj_request->kref);

1661
	dout("%s %p\n", __func__, obj_request);
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1662 1663 1664 1665 1666 1667
	return obj_request;
}

static void rbd_obj_request_destroy(struct kref *kref)
{
	struct rbd_obj_request *obj_request;
1668
	u32 i;
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1669 1670 1671

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

A
Alex Elder 已提交
1672 1673
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
1674 1675 1676 1677 1678 1679 1680
	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);

	switch (obj_request->type) {
1681
	case OBJ_REQUEST_NODATA:
A
Alex Elder 已提交
1682
	case OBJ_REQUEST_BIO:
1683
	case OBJ_REQUEST_BVECS:
1684
		break;		/* Nothing to do */
1685 1686
	default:
		rbd_assert(0);
A
Alex Elder 已提交
1687 1688
	}

1689 1690 1691 1692 1693 1694 1695
	if (obj_request->copyup_bvecs) {
		for (i = 0; i < obj_request->copyup_bvec_count; i++) {
			if (obj_request->copyup_bvecs[i].bv_page)
				__free_page(obj_request->copyup_bvecs[i].bv_page);
		}
		kfree(obj_request->copyup_bvecs);
	}
1696

1697
	kmem_cache_free(rbd_obj_request_cache, obj_request);
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1698 1699
}

A
Alex Elder 已提交
1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
/* 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;
}

1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
/*
 * 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
1733
		rbd_warn(rbd_dev, "parent reference underflow");
1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745
}

/*
 * 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)
{
1746
	int counter = 0;
1747 1748 1749 1750

	if (!rbd_dev->parent_spec)
		return false;

1751 1752 1753 1754
	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);
1755 1756

	if (counter < 0)
1757
		rbd_warn(rbd_dev, "parent reference overflow");
1758

1759
	return counter > 0;
1760 1761
}

A
Alex Elder 已提交
1762 1763 1764 1765 1766
/*
 * 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
1767 1768
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
1769
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
1770
					enum obj_operation_type op_type,
1771
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
1772 1773 1774
{
	struct rbd_img_request *img_request;

1775
	img_request = kmem_cache_zalloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
1776 1777 1778 1779
	if (!img_request)
		return NULL;

	img_request->rbd_dev = rbd_dev;
I
Ilya Dryomov 已提交
1780
	img_request->op_type = op_type;
A
Alex Elder 已提交
1781 1782
	img_request->offset = offset;
	img_request->length = length;
I
Ilya Dryomov 已提交
1783
	if (!rbd_img_is_write(img_request))
A
Alex Elder 已提交
1784
		img_request->snap_id = rbd_dev->spec->snap_id;
I
Ilya Dryomov 已提交
1785 1786 1787
	else
		img_request->snapc = snapc;

1788
	if (rbd_dev_parent_get(rbd_dev))
1789
		img_request_layered_set(img_request);
1790

A
Alex Elder 已提交
1791 1792 1793 1794
	spin_lock_init(&img_request->completion_lock);
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
1795
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
1796
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
1797

A
Alex Elder 已提交
1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
	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
1809 1810
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
1811 1812
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
1813
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
1814

1815 1816 1817 1818 1819
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

I
Ilya Dryomov 已提交
1820
	if (rbd_img_is_write(img_request))
1821
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
1822

1823
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
1824 1825
}

1826 1827 1828 1829 1830 1831 1832 1833 1834 1835
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;

1836
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
1837
						length, OBJ_OP_READ, NULL);
1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862
	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);
}

1863 1864
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
1865
	struct rbd_img_request *img_request;
1866 1867
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
1868
	bool more;
1869

1870 1871 1872
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

1873 1874 1875 1876 1877 1878
	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;

1879
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
I
Ilya Dryomov 已提交
1880
			obj_op_name(img_request->op_type), obj_request->length,
G
Guangliang Zhao 已提交
1881
			obj_request->img_offset, obj_request->offset);
1882
		rbd_warn(rbd_dev, "  result %d xferred %x",
1883 1884 1885
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
1886 1887 1888 1889 1890
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
1891 1892
	}

A
Alex Elder 已提交
1893 1894 1895 1896
	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 {
1897 1898
		blk_status_t status = errno_to_blk_status(result);

A
Alex Elder 已提交
1899
		rbd_assert(img_request->rq != NULL);
C
Christoph Hellwig 已提交
1900

1901
		more = blk_update_request(img_request->rq, status, xferred);
C
Christoph Hellwig 已提交
1902
		if (!more)
1903
			__blk_mq_end_request(img_request->rq, status);
A
Alex Elder 已提交
1904 1905 1906
	}

	return more;
1907 1908
}

1909 1910 1911 1912 1913 1914
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;

1915
	rbd_assert(obj_request_img_data_test(obj_request));
1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933
	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;
1934
		more = rbd_img_obj_end_request(obj_request);
1935 1936 1937 1938 1939 1940 1941
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
1942
	rbd_img_request_put(img_request);
1943 1944 1945 1946 1947

	if (!more)
		rbd_img_request_complete(img_request);
}

I
Ilya Dryomov 已提交
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968
static void rbd_osd_req_setup_data(struct rbd_obj_request *obj_req, u32 which)
{
	switch (obj_req->type) {
	case OBJ_REQUEST_BIO:
		osd_req_op_extent_osd_data_bio(obj_req->osd_req, which,
					       &obj_req->bio_pos,
					       obj_req->length);
		break;
	case OBJ_REQUEST_BVECS:
		rbd_assert(obj_req->bvec_pos.iter.bi_size ==
							obj_req->length);
		osd_req_op_extent_osd_data_bvec_pos(obj_req->osd_req, which,
						    &obj_req->bvec_pos);
		break;
	default:
		rbd_assert(0);
	}
}

static int rbd_obj_setup_read(struct rbd_obj_request *obj_req)
{
1969
	obj_req->osd_req = rbd_osd_req_create(obj_req, 1);
I
Ilya Dryomov 已提交
1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
	if (!obj_req->osd_req)
		return -ENOMEM;

	osd_req_op_extent_init(obj_req->osd_req, 0, CEPH_OSD_OP_READ,
			       obj_req->offset, obj_req->length, 0, 0);
	rbd_osd_req_setup_data(obj_req, 0);

	rbd_osd_req_format_read(obj_req);
	return 0;
}

static int __rbd_obj_setup_stat(struct rbd_obj_request *obj_req,
				unsigned int which)
{
	struct page **pages;

	/*
	 * The response data for a STAT call consists of:
	 *     le64 length;
	 *     struct {
	 *         le32 tv_sec;
	 *         le32 tv_nsec;
	 *     } mtime;
	 */
	pages = ceph_alloc_page_vector(1, GFP_NOIO);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	osd_req_op_init(obj_req->osd_req, which, CEPH_OSD_OP_STAT, 0);
	osd_req_op_raw_data_in_pages(obj_req->osd_req, which, pages,
				     8 + sizeof(struct ceph_timespec),
				     0, false, true);
	return 0;
}

static void __rbd_obj_setup_write(struct rbd_obj_request *obj_req,
				  unsigned int which)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
	u16 opcode;

	osd_req_op_alloc_hint_init(obj_req->osd_req, which++,
				   rbd_dev->layout.object_size,
				   rbd_dev->layout.object_size);

	if (rbd_obj_is_entire(obj_req))
		opcode = CEPH_OSD_OP_WRITEFULL;
	else
		opcode = CEPH_OSD_OP_WRITE;

	osd_req_op_extent_init(obj_req->osd_req, which, opcode,
			       obj_req->offset, obj_req->length, 0, 0);
	rbd_osd_req_setup_data(obj_req, which++);

	rbd_assert(which == obj_req->osd_req->r_num_ops);
	rbd_osd_req_format_write(obj_req);
}

static int rbd_obj_setup_write(struct rbd_obj_request *obj_req)
{
	unsigned int num_osd_ops, which = 0;
	int ret;

	if (obj_request_overlaps_parent(obj_req)) {
		obj_req->write_state = RBD_OBJ_WRITE_GUARD;
		num_osd_ops = 3; /* stat + setallochint + write/writefull */
	} else {
		obj_req->write_state = RBD_OBJ_WRITE_FLAT;
		num_osd_ops = 2; /* setallochint + write/writefull */
	}

2041
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
I
Ilya Dryomov 已提交
2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100
	if (!obj_req->osd_req)
		return -ENOMEM;

	if (obj_request_overlaps_parent(obj_req)) {
		ret = __rbd_obj_setup_stat(obj_req, which++);
		if (ret)
			return ret;
	}

	__rbd_obj_setup_write(obj_req, which);
	return 0;
}

static void __rbd_obj_setup_discard(struct rbd_obj_request *obj_req,
				    unsigned int which)
{
	u16 opcode;

	if (rbd_obj_is_entire(obj_req)) {
		if (obj_request_overlaps_parent(obj_req)) {
			opcode = CEPH_OSD_OP_TRUNCATE;
		} else {
			osd_req_op_init(obj_req->osd_req, which++,
					CEPH_OSD_OP_DELETE, 0);
			opcode = 0;
		}
	} else if (rbd_obj_is_tail(obj_req)) {
		opcode = CEPH_OSD_OP_TRUNCATE;
	} else {
		opcode = CEPH_OSD_OP_ZERO;
	}

	if (opcode)
		osd_req_op_extent_init(obj_req->osd_req, which++, opcode,
				       obj_req->offset, obj_req->length,
				       0, 0);

	rbd_assert(which == obj_req->osd_req->r_num_ops);
	rbd_osd_req_format_write(obj_req);
}

static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req)
{
	unsigned int num_osd_ops, which = 0;
	int ret;

	if (rbd_obj_is_entire(obj_req)) {
		obj_req->write_state = RBD_OBJ_WRITE_FLAT;
		num_osd_ops = 1; /* truncate/delete */
	} else {
		if (obj_request_overlaps_parent(obj_req)) {
			obj_req->write_state = RBD_OBJ_WRITE_GUARD;
			num_osd_ops = 2; /* stat + truncate/zero */
		} else {
			obj_req->write_state = RBD_OBJ_WRITE_FLAT;
			num_osd_ops = 1; /* truncate/zero */
		}
	}

2101
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
I
Ilya Dryomov 已提交
2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126
	if (!obj_req->osd_req)
		return -ENOMEM;

	if (!rbd_obj_is_entire(obj_req) &&
	    obj_request_overlaps_parent(obj_req)) {
		ret = __rbd_obj_setup_stat(obj_req, which++);
		if (ret)
			return ret;
	}

	__rbd_obj_setup_discard(obj_req, which);
	return 0;
}

/*
 * For each object request in @img_req, allocate an OSD request, add
 * individual OSD ops and prepare them for submission.  The number of
 * OSD ops depends on op_type and the overlap point (if any).
 */
static int __rbd_img_fill_request(struct rbd_img_request *img_req)
{
	struct rbd_obj_request *obj_req;
	int ret;

	for_each_obj_request(img_req, obj_req) {
I
Ilya Dryomov 已提交
2127
		switch (img_req->op_type) {
I
Ilya Dryomov 已提交
2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146
		case OBJ_OP_READ:
			ret = rbd_obj_setup_read(obj_req);
			break;
		case OBJ_OP_WRITE:
			ret = rbd_obj_setup_write(obj_req);
			break;
		case OBJ_OP_DISCARD:
			ret = rbd_obj_setup_discard(obj_req);
			break;
		default:
			rbd_assert(0);
		}
		if (ret)
			return ret;
	}

	return 0;
}

2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157
/*
 * 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
2158 2159 2160 2161
{
	struct rbd_device *rbd_dev = img_request->rbd_dev;
	struct rbd_obj_request *obj_request = NULL;
	struct rbd_obj_request *next_obj_request;
2162
	struct ceph_bio_iter bio_it;
2163
	struct ceph_bvec_iter bvec_it;
2164
	u64 img_offset;
A
Alex Elder 已提交
2165 2166
	u64 resid;

2167 2168
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2169

2170
	img_offset = img_request->offset;
A
Alex Elder 已提交
2171
	resid = img_request->length;
A
Alex Elder 已提交
2172
	rbd_assert(resid > 0);
2173 2174

	if (type == OBJ_REQUEST_BIO) {
2175
		bio_it = *(struct ceph_bio_iter *)data_desc;
2176
		rbd_assert(img_offset ==
2177
			   bio_it.iter.bi_sector << SECTOR_SHIFT);
2178 2179
	} else if (type == OBJ_REQUEST_BVECS) {
		bvec_it = *(struct ceph_bvec_iter *)data_desc;
2180 2181
	}

A
Alex Elder 已提交
2182
	while (resid) {
2183
		u64 object_no = img_offset >> rbd_dev->header.obj_order;
2184 2185
		u64 offset = rbd_segment_offset(rbd_dev, img_offset);
		u64 length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2186

2187
		obj_request = rbd_obj_request_create(type);
A
Alex Elder 已提交
2188 2189
		if (!obj_request)
			goto out_unwind;
2190

2191
		obj_request->object_no = object_no;
2192 2193 2194
		obj_request->offset = offset;
		obj_request->length = length;

2195 2196 2197 2198 2199
		/*
		 * 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
2200

2201
		if (type == OBJ_REQUEST_BIO) {
2202 2203
			obj_request->bio_pos = bio_it;
			ceph_bio_iter_advance(&bio_it, length);
2204 2205 2206 2207
		} else if (type == OBJ_REQUEST_BVECS) {
			obj_request->bvec_pos = bvec_it;
			ceph_bvec_iter_shorten(&obj_request->bvec_pos, length);
			ceph_bvec_iter_advance(&bvec_it, length);
2208
		}
A
Alex Elder 已提交
2209

2210
		obj_request->callback = rbd_img_obj_callback;
2211
		obj_request->img_offset = img_offset;
2212

2213
		img_offset += length;
A
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		resid -= length;
	}

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	return __rbd_img_fill_request(img_request);
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out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2221
		rbd_img_obj_request_del(img_request, obj_request);
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	return -ENOMEM;
}

2226
static void rbd_img_request_submit(struct rbd_img_request *img_request)
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{
	struct rbd_obj_request *obj_request;

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	dout("%s: img %p\n", __func__, img_request);
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2232
	rbd_img_request_get(img_request);
2233
	for_each_obj_request(img_request, obj_request)
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		rbd_obj_request_submit(obj_request);
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2236
	rbd_img_request_put(img_request);
A
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2237
}
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static void rbd_img_end_child_request(struct rbd_img_request *img_req);

static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req,
				    u64 img_offset, u32 bytes)
{
	struct rbd_img_request *img_req = obj_req->img_request;
	struct rbd_img_request *child_img_req;
	int ret;

	child_img_req = rbd_parent_request_create(obj_req, img_offset, bytes);
	if (!child_img_req)
		return -ENOMEM;

	child_img_req->callback = rbd_img_end_child_request;

	if (!rbd_img_is_write(img_req)) {
		switch (obj_req->type) {
		case OBJ_REQUEST_BIO:
			ret = rbd_img_request_fill(child_img_req,
						   OBJ_REQUEST_BIO,
						   &obj_req->bio_pos);
			break;
		case OBJ_REQUEST_BVECS:
			ret = rbd_img_request_fill(child_img_req,
						   OBJ_REQUEST_BVECS,
						   &obj_req->bvec_pos);
			break;
		default:
			rbd_assert(0);
		}
	} else {
		struct ceph_bvec_iter it = {
			.bvecs = obj_req->copyup_bvecs,
			.iter = { .bi_size = bytes },
		};

		ret = rbd_img_request_fill(child_img_req, OBJ_REQUEST_BVECS,
					   &it);
	}
	if (ret) {
		rbd_img_request_put(child_img_req);
		return ret;
	}

	rbd_img_request_submit(child_img_req);
	return 0;
}

static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
	int ret;

	if (obj_req->result == -ENOENT &&
	    obj_req->img_offset < rbd_dev->parent_overlap &&
	    !obj_req->tried_parent) {
		u64 obj_overlap = min(obj_req->length,
			      rbd_dev->parent_overlap - obj_req->img_offset);

		obj_req->tried_parent = true;
		ret = rbd_obj_read_from_parent(obj_req, obj_req->img_offset,
					       obj_overlap);
		if (ret) {
			obj_req->result = ret;
			return true;
		}
		return false;
	}

	/*
	 * -ENOENT means a hole in the image -- zero-fill the entire
	 * length of the request.  A short read also implies zero-fill
	 * to the end of the request.  In both cases we update xferred
	 * count to indicate the whole request was satisfied.
	 */
	if (obj_req->result == -ENOENT ||
	    (!obj_req->result && obj_req->xferred < obj_req->length)) {
		rbd_assert(!obj_req->xferred || !obj_req->result);
		rbd_obj_zero_range(obj_req, obj_req->xferred,
				   obj_req->length - obj_req->xferred);
		obj_req->result = 0;
		obj_req->xferred = obj_req->length;
	}

	return true;
}

/*
 * copyup_bvecs pages are never highmem pages
 */
static bool is_zero_bvecs(struct bio_vec *bvecs, u32 bytes)
{
	struct ceph_bvec_iter it = {
		.bvecs = bvecs,
		.iter = { .bi_size = bytes },
	};

	ceph_bvec_iter_advance_step(&it, bytes, ({
		if (memchr_inv(page_address(bv.bv_page) + bv.bv_offset, 0,
			       bv.bv_len))
			return false;
	}));
	return true;
}

static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes)
{
	unsigned int num_osd_ops = obj_req->osd_req->r_num_ops;

	dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
	rbd_assert(obj_req->osd_req->r_ops[0].op == CEPH_OSD_OP_STAT);
	rbd_osd_req_destroy(obj_req->osd_req);

	/*
	 * Create a copyup request with the same number of OSD ops as
	 * the original request.  The original request was stat + op(s),
	 * the new copyup request will be copyup + the same op(s).
	 */
2357
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
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2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375
	if (!obj_req->osd_req)
		return -ENOMEM;

	/*
	 * Only send non-zero copyup data to save some I/O and network
	 * bandwidth -- zero copyup data is equivalent to the object not
	 * existing.
	 */
	if (is_zero_bvecs(obj_req->copyup_bvecs, bytes)) {
		dout("%s obj_req %p detected zeroes\n", __func__, obj_req);
		bytes = 0;
	}

	osd_req_op_cls_init(obj_req->osd_req, 0, CEPH_OSD_OP_CALL, "rbd",
			    "copyup");
	osd_req_op_cls_request_data_bvecs(obj_req->osd_req, 0,
					  obj_req->copyup_bvecs, bytes);

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2376
	switch (obj_req->img_request->op_type) {
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	case OBJ_OP_WRITE:
		__rbd_obj_setup_write(obj_req, 1);
		break;
	case OBJ_OP_DISCARD:
		rbd_assert(!rbd_obj_is_entire(obj_req));
		__rbd_obj_setup_discard(obj_req, 1);
		break;
	default:
		rbd_assert(0);
	}

	rbd_obj_request_submit(obj_req);
	/* FIXME: in lieu of rbd_img_obj_callback() */
	rbd_img_request_put(obj_req->img_request);
	return 0;
}

2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421
static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap)
{
	u32 i;

	rbd_assert(!obj_req->copyup_bvecs);
	obj_req->copyup_bvec_count = calc_pages_for(0, obj_overlap);
	obj_req->copyup_bvecs = kcalloc(obj_req->copyup_bvec_count,
					sizeof(*obj_req->copyup_bvecs),
					GFP_NOIO);
	if (!obj_req->copyup_bvecs)
		return -ENOMEM;

	for (i = 0; i < obj_req->copyup_bvec_count; i++) {
		unsigned int len = min(obj_overlap, (u64)PAGE_SIZE);

		obj_req->copyup_bvecs[i].bv_page = alloc_page(GFP_NOIO);
		if (!obj_req->copyup_bvecs[i].bv_page)
			return -ENOMEM;

		obj_req->copyup_bvecs[i].bv_offset = 0;
		obj_req->copyup_bvecs[i].bv_len = len;
		obj_overlap -= len;
	}

	rbd_assert(!obj_overlap);
	return 0;
}

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2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519
static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
	u64 img_offset;
	u64 obj_overlap;
	int ret;

	if (!obj_request_overlaps_parent(obj_req)) {
		/*
		 * The overlap has become 0 (most likely because the
		 * image has been flattened).  Use rbd_obj_issue_copyup()
		 * to re-submit the original write request -- the copyup
		 * operation itself will be a no-op, since someone must
		 * have populated the child object while we weren't
		 * looking.  Move to WRITE_FLAT state as we'll be done
		 * with the operation once the null copyup completes.
		 */
		obj_req->write_state = RBD_OBJ_WRITE_FLAT;
		return rbd_obj_issue_copyup(obj_req, 0);
	}

	/*
	 * Determine the byte range covered by the object in the
	 * child image to which the original request was to be sent.
	 */
	img_offset = obj_req->img_offset - obj_req->offset;
	obj_overlap = rbd_dev->layout.object_size;

	/*
	 * There is no defined parent data beyond the parent
	 * overlap, so limit what we read at that boundary if
	 * necessary.
	 */
	if (img_offset + obj_overlap > rbd_dev->parent_overlap) {
		rbd_assert(img_offset < rbd_dev->parent_overlap);
		obj_overlap = rbd_dev->parent_overlap - img_offset;
	}

	ret = setup_copyup_bvecs(obj_req, obj_overlap);
	if (ret)
		return ret;

	obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
	return rbd_obj_read_from_parent(obj_req, img_offset, obj_overlap);
}

static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
{
	int ret;

again:
	switch (obj_req->write_state) {
	case RBD_OBJ_WRITE_GUARD:
		rbd_assert(!obj_req->xferred);
		if (obj_req->result == -ENOENT) {
			/*
			 * The target object doesn't exist.  Read the data for
			 * the entire target object up to the overlap point (if
			 * any) from the parent, so we can use it for a copyup.
			 */
			ret = rbd_obj_handle_write_guard(obj_req);
			if (ret) {
				obj_req->result = ret;
				return true;
			}
			return false;
		}
		/* fall through */
	case RBD_OBJ_WRITE_FLAT:
		if (!obj_req->result)
			/*
			 * There is no such thing as a successful short
			 * write -- indicate the whole request was satisfied.
			 */
			obj_req->xferred = obj_req->length;
		return true;
	case RBD_OBJ_WRITE_COPYUP:
		obj_req->write_state = RBD_OBJ_WRITE_GUARD;
		if (obj_req->result)
			goto again;

		rbd_assert(obj_req->xferred);
		ret = rbd_obj_issue_copyup(obj_req, obj_req->xferred);
		if (ret) {
			obj_req->result = ret;
			return true;
		}
		return false;
	default:
		rbd_assert(0);
	}
}

/*
 * Returns true if @obj_req is completed, or false otherwise.
 */
static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req)
{
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	switch (obj_req->img_request->op_type) {
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	case OBJ_OP_READ:
		return rbd_obj_handle_read(obj_req);
	case OBJ_OP_WRITE:
		return rbd_obj_handle_write(obj_req);
	case OBJ_OP_DISCARD:
		if (rbd_obj_handle_write(obj_req)) {
			/*
			 * Hide -ENOENT from delete/truncate/zero -- discarding
			 * a non-existent object is not a problem.
			 */
			if (obj_req->result == -ENOENT) {
				obj_req->result = 0;
				obj_req->xferred = obj_req->length;
			}
			return true;
		}
		return false;
	default:
		rbd_assert(0);
	}
}

static void rbd_img_end_child_request(struct rbd_img_request *img_req)
{
	struct rbd_obj_request *obj_req = img_req->obj_request;

	rbd_assert(test_bit(IMG_REQ_CHILD, &img_req->flags));

	obj_req->result = img_req->result;
	obj_req->xferred = img_req->xferred;
	rbd_img_request_put(img_req);

	rbd_obj_handle_request(obj_req);
}

static void rbd_obj_handle_request(struct rbd_obj_request *obj_req)
{
	if (!__rbd_obj_handle_request(obj_req))
		return;

	obj_request_done_set(obj_req);
	rbd_obj_request_complete(obj_req);
}

2565
static const struct rbd_client_id rbd_empty_cid;
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2566

2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602
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);
}

2603 2604 2605 2606 2607 2608 2609 2610 2611
static void __rbd_lock(struct rbd_device *rbd_dev, const char *cookie)
{
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);

	strcpy(rbd_dev->lock_cookie, cookie);
	rbd_set_owner_cid(rbd_dev, &cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
}

2612 2613 2614 2615
/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
2616
{
2617
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2618
	char cookie[32];
2619
	int ret;
A
Alex Elder 已提交
2620

I
Ilya Dryomov 已提交
2621 2622
	WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] != '\0');
2623

2624 2625 2626 2627
	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);
2628
	if (ret)
2629
		return ret;
A
Alex Elder 已提交
2630

2631
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
2632
	__rbd_lock(rbd_dev, cookie);
2633
	return 0;
A
Alex Elder 已提交
2634 2635
}

2636 2637 2638
/*
 * lock_rwsem must be held for write
 */
I
Ilya Dryomov 已提交
2639
static void rbd_unlock(struct rbd_device *rbd_dev)
2640
{
2641
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2642 2643
	int ret;

I
Ilya Dryomov 已提交
2644 2645
	WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] == '\0');
2646

2647
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
I
Ilya Dryomov 已提交
2648
			      RBD_LOCK_NAME, rbd_dev->lock_cookie);
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Ilya Dryomov 已提交
2649 2650
	if (ret && ret != -ENOENT)
		rbd_warn(rbd_dev, "failed to unlock: %d", ret);
2651

I
Ilya Dryomov 已提交
2652 2653
	/* treat errors as the image is unlocked */
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
I
Ilya Dryomov 已提交
2654
	rbd_dev->lock_cookie[0] = '\0';
2655 2656
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
2657 2658
}

2659 2660 2661 2662
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)
2663 2664
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2665 2666 2667 2668
	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;
2669

2670
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
2671

2672 2673 2674 2675 2676
	/* 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);
2677

2678 2679 2680
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
2681 2682
}

2683 2684
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
2685
{
2686 2687
	struct page **reply_pages;
	size_t reply_len;
2688

2689 2690 2691
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
2692

2693 2694 2695 2696
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
2697

2698
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
2699 2700
}

2701
static void rbd_notify_released_lock(struct work_struct *work)
2702
{
2703 2704
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
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Ilya Dryomov 已提交
2705

2706
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
2707 2708
}

2709
static int rbd_request_lock(struct rbd_device *rbd_dev)
2710
{
2711 2712 2713
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
2714 2715
	int ret;

2716
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
2717

2718 2719 2720 2721
	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);
2722
		goto out;
2723
	}
2724

2725 2726 2727 2728
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
2729

2730 2731 2732 2733
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
2734

2735 2736
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
2737

2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969
			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;
2970
	int ret = 0;
2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985

	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 */
I
Ilya Dryomov 已提交
2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997
	} else if (ret == -EROFS) {
		rbd_warn(rbd_dev, "peer will not release lock");
		/*
		 * If this is rbd_add_acquire_lock(), we want to fail
		 * immediately -- reuse BLACKLISTED flag.  Otherwise we
		 * want to block.
		 */
		if (!(rbd_dev->disk->flags & GENHD_FL_UP)) {
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
			/* wake "rbd map --exclusive" process */
			wake_requests(rbd_dev, false);
		}
2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025
	} 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);
3026
	/*
3027
	 * Ensure that all in-flight IO is flushed.
3028
	 *
3029 3030
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3031
	 */
3032 3033 3034 3035 3036 3037 3038 3039 3040
	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;

I
Ilya Dryomov 已提交
3041 3042 3043 3044 3045 3046 3047 3048 3049
	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);
3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129
	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);
}

3130 3131 3132 3133 3134 3135
/*
 * Returns result for ResponseMessage to be encoded (<= 0), or 1 if no
 * ResponseMessage is needed.
 */
static int rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
				   void **p)
3136 3137 3138
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
3139
	int result = 1;
3140 3141 3142 3143 3144 3145 3146 3147 3148

	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))
3149
		return result;
3150 3151

	down_read(&rbd_dev->lock_rwsem);
3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163
	if (__rbd_is_lock_owner(rbd_dev)) {
		if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED &&
		    rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid))
			goto out_unlock;

		/*
		 * encode ResponseMessage(0) so the peer can detect
		 * a missing owner
		 */
		result = 0;

		if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
I
Ilya Dryomov 已提交
3164 3165 3166 3167 3168 3169 3170 3171 3172
			if (!rbd_dev->opts->exclusive) {
				dout("%s rbd_dev %p queueing unlock_work\n",
				     __func__, rbd_dev);
				queue_work(rbd_dev->task_wq,
					   &rbd_dev->unlock_work);
			} else {
				/* refuse to release the lock */
				result = -EROFS;
			}
3173 3174
		}
	}
3175 3176

out_unlock:
3177
	up_read(&rbd_dev->lock_rwsem);
3178
	return result;
3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198
}

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
3199

3200 3201
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3202
				   buf, buf_size);
3203
	if (ret)
3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226
		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;
3227
	u8 struct_v = 0;
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
	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:
3261 3262
		ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
		if (ret <= 0)
3263
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
3264
						      cookie, ret);
3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282
		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
3283 3284
}

3285 3286
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3287
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3288
{
3289
	struct rbd_device *rbd_dev = arg;
3290

3291
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3292

3293 3294 3295 3296
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3297 3298 3299 3300
	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;
3301

3302
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3303
	}
3304
	mutex_unlock(&rbd_dev->watch_mutex);
3305 3306
}

3307
/*
3308
 * watch_mutex must be locked
3309
 */
3310
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3311 3312
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3313
	struct ceph_osd_linger_request *handle;
3314

3315
	rbd_assert(!rbd_dev->watch_handle);
3316
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3317

3318 3319 3320 3321 3322
	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);
3323

3324
	rbd_dev->watch_handle = handle;
3325 3326 3327
	return 0;
}

3328 3329 3330 3331
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3332
{
3333 3334
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3335

3336 3337
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3338

3339 3340 3341
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3342

3343
	rbd_dev->watch_handle = NULL;
3344 3345
}

3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364
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)
3365
{
3366 3367 3368
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3369 3370 3371 3372
	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);
3373 3374 3375 3376
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3377
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3378 3379 3380 3381 3382 3383 3384
	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
3385 3386

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
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
/*
 * lock_rwsem must be held for write
 */
static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	char cookie[32];
	int ret;

	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);

	format_lock_cookie(rbd_dev, cookie);
	ret = ceph_cls_set_cookie(osdc, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, RBD_LOCK_NAME,
				  CEPH_CLS_LOCK_EXCLUSIVE, rbd_dev->lock_cookie,
				  RBD_LOCK_TAG, cookie);
	if (ret) {
		if (ret != -EOPNOTSUPP)
			rbd_warn(rbd_dev, "failed to update lock cookie: %d",
				 ret);

		/*
		 * Lock cookie cannot be updated on older OSDs, so do
		 * a manual release and queue an acquire.
		 */
		if (rbd_release_lock(rbd_dev))
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->lock_dwork, 0);
	} else {
3418
		__rbd_lock(rbd_dev, cookie);
3419 3420 3421
	}
}

3422 3423 3424 3425 3426 3427 3428 3429 3430
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);
	int ret;

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

	mutex_lock(&rbd_dev->watch_mutex);
3431 3432
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
3433
		return;
3434
	}
3435 3436 3437 3438

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3439
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3440
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
3441
			wake_requests(rbd_dev, true);
3442
		} else {
3443 3444 3445
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3446 3447
		}
		mutex_unlock(&rbd_dev->watch_mutex);
3448
		return;
3449 3450 3451 3452 3453 3454
	}

	rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
	rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
	mutex_unlock(&rbd_dev->watch_mutex);

3455 3456 3457 3458 3459
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		rbd_reacquire_lock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);

3460 3461 3462 3463 3464
	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
}

3465
/*
3466 3467
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3468 3469
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3470 3471
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3472
			     const char *method_name,
3473
			     const void *outbound,
3474
			     size_t outbound_size,
3475
			     void *inbound,
3476
			     size_t inbound_size)
3477
{
3478 3479 3480
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3481 3482 3483
	int ret;

	/*
3484 3485 3486 3487 3488
	 * 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.
3489
	 */
3490 3491 3492
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3493

3494 3495 3496
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3497

3498
		memcpy(page_address(req_page), outbound, outbound_size);
3499
	}
3500

3501 3502 3503 3504 3505 3506
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3507

3508 3509 3510 3511 3512 3513 3514
	ret = ceph_osdc_call(osdc, oid, oloc, RBD_DRV_NAME, method_name,
			     CEPH_OSD_FLAG_READ, req_page, outbound_size,
			     reply_page, &inbound_size);
	if (!ret) {
		memcpy(inbound, page_address(reply_page), inbound_size);
		ret = inbound_size;
	}
3515

3516 3517 3518
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
3519 3520 3521
	return ret;
}

3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540
/*
 * 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);
3541 3542 3543
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

3544 3545 3546
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
3547
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
3548
{
C
Christoph Hellwig 已提交
3549 3550
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
3551
	struct rbd_img_request *img_request;
3552
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
3553 3554
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
3555
	enum obj_operation_type op_type;
3556
	u64 mapping_size;
I
Ilya Dryomov 已提交
3557
	bool must_be_locked;
A
Alex Elder 已提交
3558 3559
	int result;

3560 3561
	switch (req_op(rq)) {
	case REQ_OP_DISCARD:
3562
	case REQ_OP_WRITE_ZEROES:
3563
		op_type = OBJ_OP_DISCARD;
3564 3565
		break;
	case REQ_OP_WRITE:
G
Guangliang Zhao 已提交
3566
		op_type = OBJ_OP_WRITE;
3567 3568
		break;
	case REQ_OP_READ:
G
Guangliang Zhao 已提交
3569
		op_type = OBJ_OP_READ;
3570 3571 3572 3573 3574 3575
		break;
	default:
		dout("%s: non-fs request type %d\n", __func__, req_op(rq));
		result = -EIO;
		goto err;
	}
G
Guangliang Zhao 已提交
3576

I
Ilya Dryomov 已提交
3577
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
3578

I
Ilya Dryomov 已提交
3579 3580 3581 3582 3583
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
3584

3585 3586
	rbd_assert(op_type == OBJ_OP_READ ||
		   rbd_dev->spec->snap_id == CEPH_NOSNAP);
A
Alex Elder 已提交
3587

I
Ilya Dryomov 已提交
3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599
	/*
	 * 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
3600

I
Ilya Dryomov 已提交
3601 3602 3603 3604 3605 3606
	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
3607

C
Christoph Hellwig 已提交
3608 3609
	blk_mq_start_request(rq);

3610 3611
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
3612
	if (op_type != OBJ_OP_READ) {
3613 3614 3615 3616 3617 3618
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
3619
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
3620
			 length, mapping_size);
I
Ilya Dryomov 已提交
3621 3622 3623
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
3624

I
Ilya Dryomov 已提交
3625 3626 3627
	must_be_locked =
	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
3628 3629
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
3630
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
I
Ilya Dryomov 已提交
3631 3632 3633 3634 3635 3636
		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			if (rbd_dev->opts->exclusive) {
				rbd_warn(rbd_dev, "exclusive lock required");
				result = -EROFS;
				goto err_unlock;
			}
3637
			rbd_wait_state_locked(rbd_dev);
I
Ilya Dryomov 已提交
3638
		}
3639 3640 3641 3642
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
3643 3644
	}

G
Guangliang Zhao 已提交
3645
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
3646
					     snapc);
I
Ilya Dryomov 已提交
3647 3648
	if (!img_request) {
		result = -ENOMEM;
3649
		goto err_unlock;
I
Ilya Dryomov 已提交
3650 3651
	}
	img_request->rq = rq;
3652
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
3653

3654 3655 3656
	if (op_type == OBJ_OP_DISCARD)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
					      NULL);
3657 3658 3659 3660
	else {
		struct ceph_bio_iter bio_it = { .bio = rq->bio,
						.iter = rq->bio->bi_iter };

3661
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3662 3663
					      &bio_it);
	}
I
Ilya Dryomov 已提交
3664 3665
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3666

3667
	rbd_img_request_submit(img_request);
3668 3669
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3670
	return;
A
Alex Elder 已提交
3671

I
Ilya Dryomov 已提交
3672 3673
err_img_request:
	rbd_img_request_put(img_request);
3674 3675 3676
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3677 3678 3679
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
3680
			 obj_op_name(op_type), length, offset, result);
3681
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
3682
err:
3683
	blk_mq_end_request(rq, errno_to_blk_status(result));
I
Ilya Dryomov 已提交
3684
}
A
Alex Elder 已提交
3685

3686
static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
C
Christoph Hellwig 已提交
3687
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
3688
{
C
Christoph Hellwig 已提交
3689 3690
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
3691

C
Christoph Hellwig 已提交
3692
	queue_work(rbd_wq, work);
3693
	return BLK_STS_OK;
A
Alex Elder 已提交
3694 3695
}

3696 3697
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
3698 3699 3700
	blk_cleanup_queue(rbd_dev->disk->queue);
	blk_mq_free_tag_set(&rbd_dev->tag_set);
	put_disk(rbd_dev->disk);
3701
	rbd_dev->disk = NULL;
3702 3703
}

3704
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
3705 3706 3707
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
3708 3709

{
3710 3711 3712 3713
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_osd_request *req;
	struct page **pages;
	int num_pages = calc_pages_for(0, buf_len);
3714 3715
	int ret;

3716 3717 3718
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
3719

3720 3721 3722
	ceph_oid_copy(&req->r_base_oid, oid);
	ceph_oloc_copy(&req->r_base_oloc, oloc);
	req->r_flags = CEPH_OSD_FLAG_READ;
A
Alex Elder 已提交
3723

3724
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
3725
	if (ret)
3726
		goto out_req;
3727

3728 3729 3730 3731 3732
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
3733

3734 3735 3736 3737 3738 3739 3740 3741
	osd_req_op_extent_init(req, 0, CEPH_OSD_OP_READ, 0, buf_len, 0, 0);
	osd_req_op_extent_osd_data_pages(req, 0, pages, buf_len, 0, false,
					 true);

	ceph_osdc_start_request(osdc, req, false);
	ret = ceph_osdc_wait_request(osdc, req);
	if (ret >= 0)
		ceph_copy_from_page_vector(pages, buf, 0, ret);
3742

3743 3744
out_req:
	ceph_osdc_put_request(req);
3745 3746 3747
	return ret;
}

3748
/*
A
Alex Elder 已提交
3749 3750 3751
 * 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.
3752
 */
3753
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3754
{
3755
	struct rbd_image_header_ondisk *ondisk = NULL;
3756
	u32 snap_count = 0;
3757 3758 3759
	u64 names_size = 0;
	u32 want_count;
	int ret;
3760

A
Alex Elder 已提交
3761
	/*
3762 3763 3764 3765 3766
	 * 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
3767
	 */
3768 3769 3770 3771 3772 3773 3774 3775 3776 3777
	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
3778
			return -ENOMEM;
3779

3780 3781
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
3782
		if (ret < 0)
A
Alex Elder 已提交
3783
			goto out;
A
Alex Elder 已提交
3784
		if ((size_t)ret < size) {
3785
			ret = -ENXIO;
A
Alex Elder 已提交
3786 3787
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
3788
			goto out;
3789 3790 3791
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
3792
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
3793
			goto out;
3794
		}
3795

3796 3797 3798 3799
		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
3800

A
Alex Elder 已提交
3801 3802
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
3803 3804 3805
	kfree(ondisk);

	return ret;
3806 3807
}

3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826
/*
 * 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);
}

3827 3828 3829 3830 3831
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
3832 3833 3834
	 * 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.
3835
	 */
I
Ilya Dryomov 已提交
3836 3837
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
3838 3839 3840 3841 3842 3843 3844
		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
3845
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3846
{
3847
	u64 mapping_size;
A
Alex Elder 已提交
3848 3849
	int ret;

3850
	down_write(&rbd_dev->header_rwsem);
3851
	mapping_size = rbd_dev->mapping.size;
3852 3853

	ret = rbd_dev_header_info(rbd_dev);
3854
	if (ret)
3855
		goto out;
3856

3857 3858 3859 3860 3861 3862 3863
	/*
	 * 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)
3864
			goto out;
3865 3866
	}

3867
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
3868
		rbd_dev->mapping.size = rbd_dev->header.image_size;
3869 3870 3871 3872
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
3873

3874
out:
3875
	up_write(&rbd_dev->header_rwsem);
3876
	if (!ret && mapping_size != rbd_dev->mapping.size)
3877
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
3878

3879
	return ret;
A
Alex Elder 已提交
3880 3881
}

3882 3883
static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
		unsigned int hctx_idx, unsigned int numa_node)
C
Christoph Hellwig 已提交
3884 3885 3886 3887 3888 3889 3890
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

3891
static const struct blk_mq_ops rbd_mq_ops = {
C
Christoph Hellwig 已提交
3892 3893 3894 3895
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

3896 3897 3898 3899
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
3900
	u64 segment_size;
C
Christoph Hellwig 已提交
3901
	int err;
3902 3903

	/* create gendisk info */
3904 3905 3906
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
3907
	if (!disk)
A
Alex Elder 已提交
3908
		return -ENOMEM;
3909

A
Alex Elder 已提交
3910
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
3911
		 rbd_dev->dev_id);
3912
	disk->major = rbd_dev->major;
3913
	disk->first_minor = rbd_dev->minor;
3914 3915
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
3916 3917 3918
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
3919 3920
	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
3921
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
3922
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
3923
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
3924 3925 3926 3927 3928
	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)
3929
		goto out_disk;
3930

C
Christoph Hellwig 已提交
3931 3932 3933 3934 3935 3936
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

3937 3938
	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
3939

3940
	/* set io sizes to object size */
A
Alex Elder 已提交
3941 3942
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
3943
	q->limits.max_sectors = queue_max_hw_sectors(q);
3944
	blk_queue_max_segments(q, USHRT_MAX);
3945
	blk_queue_max_segment_size(q, UINT_MAX);
A
Alex Elder 已提交
3946 3947
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
3948

3949 3950 3951
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
3952
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
3953
	blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE);
3954

3955
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
3956
		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
3957

3958 3959 3960 3961 3962
	/*
	 * disk_release() expects a queue ref from add_disk() and will
	 * put it.  Hold an extra ref until add_disk() is called.
	 */
	WARN_ON(!blk_get_queue(q));
3963 3964 3965 3966 3967 3968
	disk->queue = q;
	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
3969 3970
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
3971 3972
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
3973
	return err;
3974 3975
}

3976 3977 3978 3979
/*
  sysfs
*/

A
Alex Elder 已提交
3980 3981 3982 3983 3984
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

3985 3986 3987
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3988
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3989

A
Alex Elder 已提交
3990 3991
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
3992 3993
}

A
Alex Elder 已提交
3994 3995 3996 3997 3998 3999 4000 4001 4002 4003
/*
 * 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
4004
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4005 4006
}

4007 4008 4009
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4010
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4011

A
Alex Elder 已提交
4012 4013 4014 4015
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4016 4017 4018 4019 4020 4021
}

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
4022

4023
	return sprintf(buf, "%d\n", rbd_dev->minor);
4024 4025
}

4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036
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));
}

4037 4038
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4039
{
A
Alex Elder 已提交
4040
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4041

4042
	return sprintf(buf, "client%lld\n",
4043
		       ceph_client_gid(rbd_dev->rbd_client->client));
4044 4045
}

4046 4047 4048 4049 4050 4051 4052 4053
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);
}

4054 4055 4056 4057 4058 4059
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);
4060 4061
}

4062 4063
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4064
{
A
Alex Elder 已提交
4065
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4066

4067
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4068 4069
}

4070 4071 4072 4073 4074
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);

4075
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4076
			(unsigned long long) rbd_dev->spec->pool_id);
4077 4078
}

4079 4080 4081
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4082
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4083

A
Alex Elder 已提交
4084 4085 4086 4087
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4088 4089
}

A
Alex Elder 已提交
4090 4091 4092 4093 4094
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);

4095
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4096 4097
}

A
Alex Elder 已提交
4098 4099 4100 4101
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4102 4103 4104 4105
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4106
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4107

4108
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4109 4110
}

4111 4112 4113 4114 4115 4116 4117 4118
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);
}

4119
/*
4120 4121 4122
 * 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)".
4123 4124
 */
static ssize_t rbd_parent_show(struct device *dev,
4125 4126
			       struct device_attribute *attr,
			       char *buf)
4127 4128
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4129
	ssize_t count = 0;
4130

4131
	if (!rbd_dev->parent)
4132 4133
		return sprintf(buf, "(no parent image)\n");

4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149
	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;
4150 4151
}

4152 4153 4154 4155 4156
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
4157
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4158
	int ret;
4159

A
Alex Elder 已提交
4160
	ret = rbd_dev_refresh(rbd_dev);
4161
	if (ret)
4162
		return ret;
4163

4164
	return size;
4165
}
4166

4167
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4168
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4169
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4170
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4171
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4172
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4173
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4174
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4175
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4176
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4177
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4178
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4179 4180
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4181
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4182
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4183 4184 4185

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4186
	&dev_attr_features.attr,
4187
	&dev_attr_major.attr,
4188
	&dev_attr_minor.attr,
4189
	&dev_attr_client_addr.attr,
4190
	&dev_attr_client_id.attr,
4191
	&dev_attr_cluster_fsid.attr,
4192
	&dev_attr_config_info.attr,
4193
	&dev_attr_pool.attr,
4194
	&dev_attr_pool_id.attr,
4195
	&dev_attr_name.attr,
A
Alex Elder 已提交
4196
	&dev_attr_image_id.attr,
4197
	&dev_attr_current_snap.attr,
4198
	&dev_attr_snap_id.attr,
4199
	&dev_attr_parent.attr,
4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212
	&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
};

4213
static void rbd_dev_release(struct device *dev);
4214

4215
static const struct device_type rbd_device_type = {
4216 4217
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4218
	.release	= rbd_dev_release,
4219 4220
};

4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241
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;
4242 4243 4244

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260
	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);
}

4261
static void rbd_dev_free(struct rbd_device *rbd_dev)
4262
{
4263
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4264
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4265

4266
	ceph_oid_destroy(&rbd_dev->header_oid);
4267
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4268
	kfree(rbd_dev->config_info);
4269

4270 4271 4272 4273
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286
}

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);
4287 4288 4289 4290 4291 4292 4293 4294 4295 4296

	/*
	 * 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);
}

4297 4298
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4299 4300 4301
{
	struct rbd_device *rbd_dev;

4302
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4303 4304 4305 4306 4307 4308 4309
	if (!rbd_dev)
		return NULL;

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

4310
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4311
	ceph_oid_init(&rbd_dev->header_oid);
4312
	rbd_dev->header_oloc.pool = spec->pool_id;
4313

4314 4315 4316 4317
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4318 4319 4320 4321 4322 4323 4324 4325
	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);

4326 4327 4328 4329 4330
	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);

4331
	rbd_dev->rbd_client = rbdc;
4332
	rbd_dev->spec = spec;
4333

4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363
	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;
4364

4365 4366
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4367

4368
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4369
	return rbd_dev;
4370 4371 4372 4373 4374 4375

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4376 4377 4378 4379
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4380 4381
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4382 4383
}

4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398
/*
 * 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 };

4399 4400 4401 4402
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_size",
				  &snapid, sizeof(snapid),
				  &size_buf, sizeof(size_buf));
4403
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4404 4405
	if (ret < 0)
		return ret;
4406 4407
	if (ret < sizeof (size_buf))
		return -ERANGE;
4408

J
Josh Durgin 已提交
4409
	if (order) {
4410
		*order = size_buf.order;
J
Josh Durgin 已提交
4411 4412
		dout("  order %u", (unsigned int)*order);
	}
4413 4414
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4415 4416
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4417
		(unsigned long long)*snap_size);
4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428

	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);
}

4429 4430 4431 4432 4433 4434 4435 4436 4437 4438
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;

4439 4440 4441
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_object_prefix",
				  NULL, 0, reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
4442
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4443 4444 4445 4446 4447
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4448 4449
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462

	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;
}

4463 4464 4465 4466 4467 4468 4469
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;
4470
	} __attribute__ ((packed)) features_buf = { 0 };
4471
	u64 unsup;
4472 4473
	int ret;

4474 4475 4476 4477
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_features",
				  &snapid, sizeof(snapid),
				  &features_buf, sizeof(features_buf));
4478
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4479 4480
	if (ret < 0)
		return ret;
4481 4482
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4483

4484 4485 4486 4487
	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
4488
		return -ENXIO;
4489
	}
A
Alex Elder 已提交
4490

4491 4492 4493
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4494 4495 4496
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4497 4498 4499 4500 4501 4502 4503 4504 4505 4506

	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);
}

4507 4508 4509 4510 4511 4512 4513 4514
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
4515
	u64 pool_id;
4516
	char *image_id;
4517
	u64 snap_id;
4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534
	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;
	}

4535
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4536 4537 4538
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
4539
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4540 4541 4542 4543
	if (ret < 0)
		goto out_err;

	p = reply_buf;
4544 4545
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
4546
	ceph_decode_64_safe(&p, end, pool_id, out_err);
4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563
	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);
		}

4564
		goto out;	/* No parent?  No problem. */
4565
	}
4566

4567 4568 4569
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
4570
	if (pool_id > (u64)U32_MAX) {
4571
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
4572
			(unsigned long long)pool_id, U32_MAX);
4573
		goto out_err;
A
Alex Elder 已提交
4574
	}
4575

A
Alex Elder 已提交
4576
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4577 4578 4579 4580
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
4581
	ceph_decode_64_safe(&p, end, snap_id, out_err);
4582 4583
	ceph_decode_64_safe(&p, end, overlap, out_err);

4584 4585 4586 4587 4588 4589 4590 4591 4592
	/*
	 * 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
4593 4594
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
4595 4596
	} else {
		kfree(image_id);
4597 4598 4599
	}

	/*
4600 4601
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
4602 4603 4604
	 */
	if (!overlap) {
		if (parent_spec) {
4605 4606 4607 4608
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
4609
		} else {
4610 4611
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
4612
		}
A
Alex Elder 已提交
4613
	}
4614 4615
	rbd_dev->parent_overlap = overlap;

4616 4617 4618 4619 4620 4621 4622 4623 4624
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637
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;

4638 4639 4640
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, "get_stripe_unit_count",
				NULL, 0, &striping_info_buf, size);
4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653
	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;
I
Ilya Dryomov 已提交
4654
	obj_size = rbd_obj_bytes(&rbd_dev->header);
4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668
	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;
	}
4669 4670
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
4671 4672 4673 4674

	return 0;
}

4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692
static int rbd_dev_v2_data_pool(struct rbd_device *rbd_dev)
{
	__le64 data_pool_id;
	int ret;

	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_data_pool",
				  NULL, 0, &data_pool_id, sizeof(data_pool_id));
	if (ret < 0)
		return ret;
	if (ret < sizeof(data_pool_id))
		return -EBADMSG;

	rbd_dev->header.data_pool_id = le64_to_cpu(data_pool_id);
	WARN_ON(rbd_dev->header.data_pool_id == CEPH_NOPOOL);
	return 0;
}

4693 4694
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
4695
	CEPH_DEFINE_OID_ONSTACK(oid);
4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707
	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
4708 4709
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
4710 4711 4712 4713 4714
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
4715
	end = image_id + image_id_size;
4716
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
4717 4718 4719 4720 4721 4722

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

4723 4724 4725 4726
	ceph_oid_printf(&oid, "%s", RBD_DIRECTORY);
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "dir_get_name", image_id, image_id_size,
				  reply_buf, size);
4727 4728 4729
	if (ret < 0)
		goto out;
	p = reply_buf;
4730 4731
	end = reply_buf + ret;

4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743
	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;
}

4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773
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);
4774 4775 4776 4777 4778 4779 4780
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798
		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);
}

4799
/*
4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826
 * 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.
4827
 *
4828 4829
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
4830
 */
4831
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
4832
{
4833 4834 4835 4836 4837
	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;
4838 4839
	int ret;

4840 4841 4842
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
4843

4844
	/* Get the pool name; we have to make our own copy of this */
4845

4846 4847 4848
	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);
4849 4850
		return -EIO;
	}
4851 4852
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
4853 4854 4855 4856
		return -ENOMEM;

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

4857 4858
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
4859
		rbd_warn(rbd_dev, "unable to get image name");
4860

4861
	/* Fetch the snapshot name */
4862

4863
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4864 4865
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
4866
		goto out_err;
4867 4868 4869 4870 4871
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
4872 4873

	return 0;
4874

4875
out_err:
4876 4877
	kfree(image_name);
	kfree(pool_name);
4878 4879 4880
	return ret;
}

A
Alex Elder 已提交
4881
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904
{
	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;

4905 4906 4907
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
4908
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4909 4910 4911 4912
	if (ret < 0)
		goto out;

	p = reply_buf;
4913 4914
	end = reply_buf + ret;
	ret = -ERANGE;
4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930
	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;
4931
	ret = 0;
4932

4933
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4934 4935 4936 4937 4938 4939 4940 4941
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

4942
	ceph_put_snap_context(rbd_dev->header.snapc);
4943 4944 4945
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
4946
		(unsigned long long)seq, (unsigned int)snap_count);
4947 4948 4949
out:
	kfree(reply_buf);

4950
	return ret;
4951 4952
}

4953 4954
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
4955 4956 4957
{
	size_t size;
	void *reply_buf;
4958
	__le64 snapid;
A
Alex Elder 已提交
4959 4960 4961 4962 4963 4964 4965 4966 4967 4968
	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);

4969
	snapid = cpu_to_le64(snap_id);
4970 4971 4972
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
4973
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4974 4975
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
4976
		goto out;
4977
	}
A
Alex Elder 已提交
4978 4979

	p = reply_buf;
4980
	end = reply_buf + ret;
A
Alex Elder 已提交
4981
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4982
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
4983 4984
		goto out;

4985
	dout("  snap_id 0x%016llx snap_name = %s\n",
4986
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
4987 4988 4989
out:
	kfree(reply_buf);

4990
	return snap_name;
A
Alex Elder 已提交
4991 4992
}

4993
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4994
{
4995
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
4996 4997
	int ret;

4998 4999
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5000
		return ret;
5001

5002 5003 5004
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5005
			return ret;
5006 5007
	}

A
Alex Elder 已提交
5008
	ret = rbd_dev_v2_snap_context(rbd_dev);
5009 5010 5011 5012
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5013 5014 5015 5016

	return ret;
}

5017 5018 5019 5020 5021 5022 5023 5024 5025 5026
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);
}

5027 5028 5029
/*
 * 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
5030 5031
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045
 */
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
5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067
/*
 * 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
5068
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5069 5070 5071 5072 5073 5074 5075 5076 5077 5078 5079
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5080
/*
5081 5082 5083 5084
 * 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
5085
 *
5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119
 * 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.
5120
 */
5121
static int rbd_add_parse_args(const char *buf,
5122
				struct ceph_options **ceph_opts,
5123 5124
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5125
{
A
Alex Elder 已提交
5126
	size_t len;
5127
	char *options;
5128
	const char *mon_addrs;
5129
	char *snap_name;
5130
	size_t mon_addrs_size;
5131
	struct rbd_spec *spec = NULL;
5132
	struct rbd_options *rbd_opts = NULL;
5133
	struct ceph_options *copts;
5134
	int ret;
5135 5136 5137

	/* The first four tokens are required */

5138
	len = next_token(&buf);
5139 5140 5141 5142
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5143
	mon_addrs = buf;
5144
	mon_addrs_size = len + 1;
5145
	buf += len;
5146

5147
	ret = -EINVAL;
5148 5149
	options = dup_token(&buf, NULL);
	if (!options)
5150
		return -ENOMEM;
5151 5152 5153 5154
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5155

5156 5157
	spec = rbd_spec_alloc();
	if (!spec)
5158
		goto out_mem;
5159 5160 5161 5162

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5163 5164 5165 5166
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5167

A
Alex Elder 已提交
5168
	spec->image_name = dup_token(&buf, NULL);
5169
	if (!spec->image_name)
5170
		goto out_mem;
5171 5172 5173 5174
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5175

5176 5177 5178 5179
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5180
	len = next_token(&buf);
5181
	if (!len) {
5182 5183
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5184
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5185
		ret = -ENAMETOOLONG;
5186
		goto out_err;
5187
	}
5188 5189
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5190
		goto out_mem;
5191 5192
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5193

5194
	/* Initialize all rbd options to the defaults */
5195

5196 5197 5198 5199 5200
	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
5201
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5202
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
I
Ilya Dryomov 已提交
5203
	rbd_opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
A
Alex Elder 已提交
5204

5205
	copts = ceph_parse_options(options, mon_addrs,
5206
					mon_addrs + mon_addrs_size - 1,
5207
					parse_rbd_opts_token, rbd_opts);
5208 5209
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5210 5211
		goto out_err;
	}
5212 5213 5214
	kfree(options);

	*ceph_opts = copts;
5215
	*opts = rbd_opts;
5216
	*rbd_spec = spec;
5217

5218
	return 0;
5219
out_mem:
5220
	ret = -ENOMEM;
A
Alex Elder 已提交
5221
out_err:
5222 5223
	kfree(rbd_opts);
	rbd_spec_put(spec);
5224
	kfree(options);
A
Alex Elder 已提交
5225

5226
	return ret;
5227 5228
}

5229 5230 5231 5232 5233
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5234
	struct ceph_options *opts = rbdc->client->options;
5235 5236 5237 5238 5239 5240 5241
	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) {
5242 5243
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5244 5245 5246 5247
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5248
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5249
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5250 5251
						     newest_epoch,
						     opts->mount_timeout);
5252 5253 5254 5255 5256 5257 5258 5259 5260 5261
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

I
Ilya Dryomov 已提交
5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288
static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
{
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
}

static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
{
	if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
		rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
		return -EINVAL;
	}

	/* FIXME: "rbd map --exclusive" should be in interruptible */
	down_read(&rbd_dev->lock_rwsem);
	rbd_wait_state_locked(rbd_dev);
	up_read(&rbd_dev->lock_rwsem);
	if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
		rbd_warn(rbd_dev, "failed to acquire exclusive lock");
		return -EROFS;
	}

	return 0;
}

A
Alex Elder 已提交
5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306
/*
 * 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;
5307
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5308
	void *response;
5309
	char *image_id;
5310

A
Alex Elder 已提交
5311 5312 5313
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5314 5315
	 * 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
5316
	 */
5317 5318 5319
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5320
		return 0;
5321
	}
A
Alex Elder 已提交
5322

A
Alex Elder 已提交
5323 5324 5325 5326
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5327 5328 5329 5330 5331 5332
	ret = ceph_oid_aprintf(&oid, GFP_KERNEL, "%s%s", RBD_ID_PREFIX,
			       rbd_dev->spec->image_name);
	if (ret)
		return ret;

	dout("rbd id object name is %s\n", oid.name);
A
Alex Elder 已提交
5333 5334 5335 5336 5337 5338 5339 5340 5341 5342

	/* 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;
	}

5343 5344
	/* If it doesn't exist we'll assume it's a format 1 image */

5345 5346 5347
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5348
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5349 5350 5351 5352 5353
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5354
	} else if (ret >= 0) {
5355 5356 5357
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5358
						NULL, GFP_NOIO);
5359
		ret = PTR_ERR_OR_ZERO(image_id);
5360 5361 5362 5363 5364 5365 5366
		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
5367 5368 5369
	}
out:
	kfree(response);
5370
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5371 5372 5373
	return ret;
}

A
Alex Elder 已提交
5374 5375 5376 5377
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5378 5379 5380 5381
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5382
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5383 5384 5385 5386

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

	header = &rbd_dev->header;
5387
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5388 5389 5390 5391 5392 5393
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5394
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5395 5396 5397
{
	int ret;

5398
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5399
	if (ret)
5400 5401
		goto out_err;

5402 5403 5404 5405
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5406
	ret = rbd_dev_v2_features(rbd_dev);
5407
	if (ret)
5408
		goto out_err;
5409

5410 5411 5412 5413 5414 5415 5416
	/* 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;
	}
5417

5418 5419 5420 5421 5422 5423
	if (rbd_dev->header.features & RBD_FEATURE_DATA_POOL) {
		ret = rbd_dev_v2_data_pool(rbd_dev);
		if (ret)
			goto out_err;
	}

I
Ilya Dryomov 已提交
5424
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5425
	return 0;
I
Ilya Dryomov 已提交
5426

5427
out_err:
A
Alex Elder 已提交
5428
	rbd_dev->header.features = 0;
5429 5430
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5431
	return ret;
5432 5433
}

5434 5435 5436 5437 5438 5439
/*
 * @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
5440
{
5441
	struct rbd_device *parent = NULL;
5442 5443 5444 5445 5446
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5447 5448 5449 5450 5451 5452
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5453
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5454 5455
	if (!parent) {
		ret = -ENOMEM;
5456
		goto out_err;
5457 5458 5459 5460 5461 5462 5463 5464
	}

	/*
	 * 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);
5465

5466
	ret = rbd_dev_image_probe(parent, depth);
5467 5468
	if (ret < 0)
		goto out_err;
5469

5470
	rbd_dev->parent = parent;
5471
	atomic_set(&rbd_dev->parent_ref, 1);
5472
	return 0;
5473

5474
out_err:
5475
	rbd_dev_unparent(rbd_dev);
5476
	rbd_dev_destroy(parent);
5477 5478 5479
	return ret;
}

5480 5481 5482 5483 5484 5485 5486 5487 5488
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
{
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
	rbd_dev_mapping_clear(rbd_dev);
	rbd_free_disk(rbd_dev);
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
}

I
Ilya Dryomov 已提交
5489 5490 5491 5492
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5493
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5494
{
A
Alex Elder 已提交
5495
	int ret;
A
Alex Elder 已提交
5496

5497
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5498

5499 5500 5501
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5502
			goto err_out_unlock;
5503 5504 5505 5506 5507 5508 5509

		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
5510 5511 5512 5513 5514 5515 5516

	/* Set up the blkdev mapping. */

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

5517
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5518 5519
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5520

5521
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5522
	set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only);
5523

5524
	ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
5525
	if (ret)
5526
		goto err_out_mapping;
A
Alex Elder 已提交
5527

5528
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5529
	up_write(&rbd_dev->header_rwsem);
5530
	return 0;
5531

5532 5533
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5534 5535 5536
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5537 5538
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
5539 5540
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5541 5542 5543
	return ret;
}

A
Alex Elder 已提交
5544 5545 5546
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
5547
	int ret;
A
Alex Elder 已提交
5548 5549 5550 5551 5552

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

	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
	if (rbd_dev->image_format == 1)
5553 5554
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
5555
	else
5556 5557
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
5558

5559
	return ret;
A
Alex Elder 已提交
5560 5561
}

5562 5563
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5564
	rbd_dev_unprobe(rbd_dev);
5565 5566
	if (rbd_dev->opts)
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5567 5568 5569
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5570 5571
}

5572 5573
/*
 * Probe for the existence of the header object for the given rbd
5574 5575 5576
 * 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.
5577
 */
5578
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
5579 5580 5581 5582
{
	int ret;

	/*
A
Alex Elder 已提交
5583 5584 5585 5586
	 * 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.
5587 5588 5589
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
5590 5591
		return ret;

A
Alex Elder 已提交
5592 5593 5594 5595
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

5596
	if (!depth) {
5597
		ret = rbd_register_watch(rbd_dev);
5598 5599 5600 5601 5602
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
5603
			goto err_out_format;
5604
		}
5605
	}
5606

5607
	ret = rbd_dev_header_info(rbd_dev);
5608
	if (ret)
5609
		goto err_out_watch;
A
Alex Elder 已提交
5610

5611 5612 5613 5614 5615 5616
	/*
	 * 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.
	 */
5617
	if (!depth)
5618 5619 5620
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
5621 5622 5623 5624 5625 5626
	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
5627
		goto err_out_probe;
5628
	}
5629

5630 5631 5632 5633 5634 5635 5636 5637 5638
	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.
		 */
5639
		if (!depth && rbd_dev->parent_spec)
5640 5641 5642 5643
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

5644
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
5645 5646 5647 5648
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
5649
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
5650
	return 0;
5651

A
Alex Elder 已提交
5652 5653
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
5654
err_out_watch:
5655
	if (!depth)
5656
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5657 5658
err_out_format:
	rbd_dev->image_format = 0;
5659 5660
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5661 5662 5663
	return ret;
}

5664 5665 5666
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
5667
{
5668
	struct rbd_device *rbd_dev = NULL;
5669
	struct ceph_options *ceph_opts = NULL;
5670
	struct rbd_options *rbd_opts = NULL;
5671
	struct rbd_spec *spec = NULL;
5672
	struct rbd_client *rbdc;
5673
	int rc;
5674 5675 5676 5677 5678

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

	/* parse add command */
5679
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
5680
	if (rc < 0)
5681
		goto out;
5682

5683 5684 5685
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
5686
		goto err_out_args;
5687
	}
5688 5689

	/* pick the pool */
5690
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
5691 5692 5693
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
5694
		goto err_out_client;
5695
	}
A
Alex Elder 已提交
5696
	spec->pool_id = (u64)rc;
5697

5698
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
5699 5700
	if (!rbd_dev) {
		rc = -ENOMEM;
5701
		goto err_out_client;
5702
	}
5703 5704
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
5705
	rbd_opts = NULL;	/* rbd_dev now owns this */
5706

5707 5708 5709 5710 5711 5712
	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
5713
	down_write(&rbd_dev->header_rwsem);
5714
	rc = rbd_dev_image_probe(rbd_dev, 0);
5715 5716
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
5717
		goto err_out_rbd_dev;
5718
	}
5719

5720 5721
	/* If we are mapping a snapshot it must be marked read-only */
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
5722
		rbd_dev->opts->read_only = true;
5723

5724
	rc = rbd_dev_device_setup(rbd_dev);
5725
	if (rc)
5726
		goto err_out_image_probe;
A
Alex Elder 已提交
5727

I
Ilya Dryomov 已提交
5728 5729 5730 5731
	if (rbd_dev->opts->exclusive) {
		rc = rbd_add_acquire_lock(rbd_dev);
		if (rc)
			goto err_out_device_setup;
A
Alex Elder 已提交
5732 5733
	}

5734 5735 5736 5737
	/* Everything's ready.  Announce the disk to the world. */

	rc = device_add(&rbd_dev->dev);
	if (rc)
I
Ilya Dryomov 已提交
5738
		goto err_out_image_lock;
5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750

	add_disk(rbd_dev->disk);
	/* see rbd_init_disk() */
	blk_put_queue(rbd_dev->disk->queue);

	spin_lock(&rbd_dev_list_lock);
	list_add_tail(&rbd_dev->node, &rbd_dev_list);
	spin_unlock(&rbd_dev_list_lock);

	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);
5751 5752 5753 5754
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
5755

I
Ilya Dryomov 已提交
5756 5757
err_out_image_lock:
	rbd_dev_image_unlock(rbd_dev);
5758 5759
err_out_device_setup:
	rbd_dev_device_release(rbd_dev);
5760 5761
err_out_image_probe:
	rbd_dev_image_release(rbd_dev);
5762 5763
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
5764
err_out_client:
5765
	rbd_put_client(rbdc);
5766
err_out_args:
5767
	rbd_spec_put(spec);
5768
	kfree(rbd_opts);
5769
	goto out;
5770 5771
}

5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 5788
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);
}

5789 5790
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5791
	while (rbd_dev->parent) {
5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 5803
		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
5804
		rbd_assert(second);
5805
		rbd_dev_image_release(second);
5806
		rbd_dev_destroy(second);
A
Alex Elder 已提交
5807 5808 5809 5810
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
5811 5812 5813 5814 5815
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

5816 5817 5818
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
5819 5820
{
	struct rbd_device *rbd_dev = NULL;
5821 5822
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
5823
	char opt_buf[6];
5824
	bool already = false;
M
Mike Christie 已提交
5825
	bool force = false;
5826
	int ret;
5827

M
Mike Christie 已提交
5828 5829 5830 5831 5832
	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");
5833
		return -EINVAL;
M
Mike Christie 已提交
5834 5835 5836 5837 5838 5839 5840 5841 5842
	}
	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;
		}
	}
5843

5844 5845 5846 5847 5848 5849 5850 5851
	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;
		}
5852
	}
5853 5854
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
5855
		if (rbd_dev->open_count && !force)
5856 5857
			ret = -EBUSY;
		else
5858 5859
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
5860 5861 5862
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
5863
	if (ret < 0 || already)
5864
		return ret;
5865

M
Mike Christie 已提交
5866 5867 5868 5869 5870 5871 5872 5873 5874
	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);
	}

5875 5876 5877 5878 5879
	del_gendisk(rbd_dev->disk);
	spin_lock(&rbd_dev_list_lock);
	list_del_init(&rbd_dev->node);
	spin_unlock(&rbd_dev_list_lock);
	device_del(&rbd_dev->dev);
5880

I
Ilya Dryomov 已提交
5881
	rbd_dev_image_unlock(rbd_dev);
5882
	rbd_dev_device_release(rbd_dev);
5883
	rbd_dev_image_release(rbd_dev);
5884
	rbd_dev_destroy(rbd_dev);
5885
	return count;
5886 5887
}

5888 5889 5890 5891 5892 5893 5894 5895 5896 5897 5898 5899 5900 5901 5902 5903 5904
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);
}

5905 5906
/*
 * create control files in sysfs
5907
 * /sys/bus/rbd/...
5908 5909 5910
 */
static int rbd_sysfs_init(void)
{
5911
	int ret;
5912

5913
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
5914
	if (ret < 0)
5915
		return ret;
5916

5917 5918 5919
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
5920 5921 5922 5923 5924 5925

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
5926
	bus_unregister(&rbd_bus_type);
5927
	device_unregister(&rbd_root_dev);
5928 5929
}

5930 5931 5932
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
5933
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
5934 5935 5936 5937
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
5938
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
5939 5940 5941
	if (!rbd_obj_request_cache)
		goto out_err;

5942
	return 0;
5943

5944
out_err:
5945 5946
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
5947 5948 5949 5950 5951
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
5952 5953 5954 5955
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

5956 5957 5958 5959 5960
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
5961
static int __init rbd_init(void)
5962 5963 5964
{
	int rc;

5965 5966 5967 5968
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
5969

5970
	rc = rbd_slab_init();
5971 5972
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
5973

5974 5975
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
5976
	 * rbd devices * queue depth, so leave @max_active at default.
5977 5978 5979 5980 5981 5982 5983
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

5984 5985 5986 5987
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
5988
			goto err_out_wq;
5989 5990 5991
		}
	}

5992 5993
	rc = rbd_sysfs_init();
	if (rc)
5994 5995 5996 5997 5998 5999
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6000

I
Ilya Dryomov 已提交
6001 6002
	return 0;

6003 6004 6005
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6006 6007
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6008 6009
err_out_slab:
	rbd_slab_exit();
6010
	return rc;
6011 6012
}

A
Alex Elder 已提交
6013
static void __exit rbd_exit(void)
6014
{
I
Ilya Dryomov 已提交
6015
	ida_destroy(&rbd_dev_id_ida);
6016
	rbd_sysfs_cleanup();
6017 6018
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6019
	destroy_workqueue(rbd_wq);
6020
	rbd_slab_exit();
6021 6022 6023 6024 6025
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
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MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
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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>");

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