rbd.c 151.2 KB
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/*
   rbd.c -- Export ceph rados objects as a Linux block device


   based on drivers/block/osdblk.c:

   Copyright 2009 Red Hat, Inc.

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

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

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



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

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

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

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

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

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

	atomic_dec(v);

	return -EINVAL;
}

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

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

	atomic_inc(v);

	return -EINVAL;
}

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

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

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

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

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

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/* Feature bits */

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#define RBD_FEATURE_LAYERING		(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;
}

static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
2229
	struct rbd_obj_request *next_obj_request;
2230
	int ret = 0;
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	dout("%s: img %p\n", __func__, img_request);
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2234 2235
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
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		rbd_obj_request_submit(obj_request);
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	}

2239 2240
	rbd_img_request_put(img_request);
	return ret;
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}
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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).
	 */
2361
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
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	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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	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;
}

2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425
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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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);
}

2569
static const struct rbd_client_id rbd_empty_cid;
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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 2603 2604 2605 2606
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);
}

2607 2608 2609 2610 2611 2612 2613 2614 2615
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);
}

2616 2617 2618 2619
/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
2620
{
2621
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2622
	char cookie[32];
2623
	int ret;
A
Alex Elder 已提交
2624

I
Ilya Dryomov 已提交
2625 2626
	WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] != '\0');
2627

2628 2629 2630 2631
	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);
2632
	if (ret)
2633
		return ret;
A
Alex Elder 已提交
2634

2635
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
2636
	__rbd_lock(rbd_dev, cookie);
2637
	return 0;
A
Alex Elder 已提交
2638 2639
}

2640 2641 2642
/*
 * lock_rwsem must be held for write
 */
I
Ilya Dryomov 已提交
2643
static void rbd_unlock(struct rbd_device *rbd_dev)
2644
{
2645
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2646 2647
	int ret;

I
Ilya Dryomov 已提交
2648 2649
	WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] == '\0');
2650

2651
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
I
Ilya Dryomov 已提交
2652
			      RBD_LOCK_NAME, rbd_dev->lock_cookie);
I
Ilya Dryomov 已提交
2653 2654
	if (ret && ret != -ENOENT)
		rbd_warn(rbd_dev, "failed to unlock: %d", ret);
2655

I
Ilya Dryomov 已提交
2656 2657
	/* treat errors as the image is unlocked */
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
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Ilya Dryomov 已提交
2658
	rbd_dev->lock_cookie[0] = '\0';
2659 2660
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
2661 2662
}

2663 2664 2665 2666
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)
2667 2668
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2669 2670 2671 2672
	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;
2673

2674
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
2675

2676 2677 2678 2679 2680
	/* 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);
2681

2682 2683 2684
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
2685 2686
}

2687 2688
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
2689
{
2690 2691
	struct page **reply_pages;
	size_t reply_len;
2692

2693 2694 2695
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
2696

2697 2698 2699 2700
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
2701

2702
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
2703 2704
}

2705
static void rbd_notify_released_lock(struct work_struct *work)
2706
{
2707 2708
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
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Ilya Dryomov 已提交
2709

2710
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
2711 2712
}

2713
static int rbd_request_lock(struct rbd_device *rbd_dev)
2714
{
2715 2716 2717
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
2718 2719
	int ret;

2720
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
2721

2722 2723 2724 2725
	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);
2726
		goto out;
2727
	}
2728

2729 2730 2731 2732
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
2733

2734 2735 2736 2737
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
2738

2739 2740
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
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 2970 2971 2972 2973
			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;
2974
	int ret = 0;
2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989

	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
2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001
	} 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);
		}
3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029
	} 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);
3030
	/*
3031
	 * Ensure that all in-flight IO is flushed.
3032
	 *
3033 3034
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3035
	 */
3036 3037 3038 3039 3040 3041 3042 3043 3044
	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
3045 3046 3047 3048 3049 3050 3051 3052 3053
	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);
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 3130 3131 3132 3133
	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);
}

3134 3135 3136 3137 3138 3139
/*
 * 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)
3140 3141 3142
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
3143
	int result = 1;
3144 3145 3146 3147 3148 3149 3150 3151 3152

	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))
3153
		return result;
3154 3155

	down_read(&rbd_dev->lock_rwsem);
3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167
	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
3168 3169 3170 3171 3172 3173 3174 3175 3176
			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;
			}
3177 3178
		}
	}
3179 3180

out_unlock:
3181
	up_read(&rbd_dev->lock_rwsem);
3182
	return result;
3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202
}

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
3203

3204 3205
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3206
				   buf, buf_size);
3207
	if (ret)
3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230
		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;
3231
	u8 struct_v = 0;
3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264
	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:
3265 3266
		ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
		if (ret <= 0)
3267
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
3268
						      cookie, ret);
3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286
		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
3287 3288
}

3289 3290
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3291
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3292
{
3293
	struct rbd_device *rbd_dev = arg;
3294

3295
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3296

3297 3298 3299 3300
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3301 3302 3303 3304
	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;
3305

3306
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3307
	}
3308
	mutex_unlock(&rbd_dev->watch_mutex);
3309 3310
}

3311
/*
3312
 * watch_mutex must be locked
3313
 */
3314
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3315 3316
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3317
	struct ceph_osd_linger_request *handle;
3318

3319
	rbd_assert(!rbd_dev->watch_handle);
3320
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3321

3322 3323 3324 3325 3326
	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);
3327

3328
	rbd_dev->watch_handle = handle;
3329 3330 3331
	return 0;
}

3332 3333 3334 3335
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3336
{
3337 3338
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3339

3340 3341
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3342

3343 3344 3345
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3346

3347
	rbd_dev->watch_handle = NULL;
3348 3349
}

3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368
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)
3369
{
3370 3371 3372
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3373 3374 3375 3376
	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);
3377 3378 3379 3380
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3381
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3382 3383 3384 3385 3386 3387 3388
	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
3389 3390

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3391 3392
}

3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421
/*
 * 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 {
3422
		__rbd_lock(rbd_dev, cookie);
3423 3424 3425
	}
}

3426 3427 3428 3429 3430 3431 3432 3433 3434
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);
3435 3436
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
3437
		return;
3438
	}
3439 3440 3441 3442

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3443
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3444
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
3445
			wake_requests(rbd_dev, true);
3446
		} else {
3447 3448 3449
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3450 3451
		}
		mutex_unlock(&rbd_dev->watch_mutex);
3452
		return;
3453 3454 3455 3456 3457 3458
	}

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

3459 3460 3461 3462 3463
	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);

3464 3465 3466 3467 3468
	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
}

3469
/*
3470 3471
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3472 3473
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3474 3475
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3476
			     const char *method_name,
3477
			     const void *outbound,
3478
			     size_t outbound_size,
3479
			     void *inbound,
3480
			     size_t inbound_size)
3481
{
3482 3483 3484
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3485 3486 3487
	int ret;

	/*
3488 3489 3490 3491 3492
	 * 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.
3493
	 */
3494 3495 3496
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3497

3498 3499 3500
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3501

3502
		memcpy(page_address(req_page), outbound, outbound_size);
3503
	}
3504

3505 3506 3507 3508 3509 3510
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3511

3512 3513 3514 3515 3516 3517 3518
	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;
	}
3519

3520 3521 3522
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
3523 3524 3525
	return ret;
}

3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544
/*
 * 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);
3545 3546 3547
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

3548 3549 3550
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
3551
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
3552
{
C
Christoph Hellwig 已提交
3553 3554
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
3555
	struct rbd_img_request *img_request;
3556
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
3557 3558
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
3559
	enum obj_operation_type op_type;
3560
	u64 mapping_size;
I
Ilya Dryomov 已提交
3561
	bool must_be_locked;
A
Alex Elder 已提交
3562 3563
	int result;

3564 3565
	switch (req_op(rq)) {
	case REQ_OP_DISCARD:
3566
	case REQ_OP_WRITE_ZEROES:
3567
		op_type = OBJ_OP_DISCARD;
3568 3569
		break;
	case REQ_OP_WRITE:
G
Guangliang Zhao 已提交
3570
		op_type = OBJ_OP_WRITE;
3571 3572
		break;
	case REQ_OP_READ:
G
Guangliang Zhao 已提交
3573
		op_type = OBJ_OP_READ;
3574 3575 3576 3577 3578 3579
		break;
	default:
		dout("%s: non-fs request type %d\n", __func__, req_op(rq));
		result = -EIO;
		goto err;
	}
G
Guangliang Zhao 已提交
3580

I
Ilya Dryomov 已提交
3581
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
3582

I
Ilya Dryomov 已提交
3583 3584 3585 3586 3587
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
3588

3589 3590
	rbd_assert(op_type == OBJ_OP_READ ||
		   rbd_dev->spec->snap_id == CEPH_NOSNAP);
A
Alex Elder 已提交
3591

I
Ilya Dryomov 已提交
3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603
	/*
	 * 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
3604

I
Ilya Dryomov 已提交
3605 3606 3607 3608 3609 3610
	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
3611

C
Christoph Hellwig 已提交
3612 3613
	blk_mq_start_request(rq);

3614 3615
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
3616
	if (op_type != OBJ_OP_READ) {
3617 3618 3619 3620 3621 3622
		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
3623
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
3624
			 length, mapping_size);
I
Ilya Dryomov 已提交
3625 3626 3627
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
3628

I
Ilya Dryomov 已提交
3629 3630 3631
	must_be_locked =
	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
3632 3633
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
3634
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
I
Ilya Dryomov 已提交
3635 3636 3637 3638 3639 3640
		    !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;
			}
3641
			rbd_wait_state_locked(rbd_dev);
I
Ilya Dryomov 已提交
3642
		}
3643 3644 3645 3646
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
3647 3648
	}

G
Guangliang Zhao 已提交
3649
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
3650
					     snapc);
I
Ilya Dryomov 已提交
3651 3652
	if (!img_request) {
		result = -ENOMEM;
3653
		goto err_unlock;
I
Ilya Dryomov 已提交
3654 3655
	}
	img_request->rq = rq;
3656
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
3657

3658 3659 3660
	if (op_type == OBJ_OP_DISCARD)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
					      NULL);
3661 3662 3663 3664
	else {
		struct ceph_bio_iter bio_it = { .bio = rq->bio,
						.iter = rq->bio->bi_iter };

3665
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3666 3667
					      &bio_it);
	}
I
Ilya Dryomov 已提交
3668 3669
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3670

I
Ilya Dryomov 已提交
3671 3672 3673
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3674

3675 3676
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3677
	return;
A
Alex Elder 已提交
3678

I
Ilya Dryomov 已提交
3679 3680
err_img_request:
	rbd_img_request_put(img_request);
3681 3682 3683
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3684 3685 3686
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
3687
			 obj_op_name(op_type), length, offset, result);
3688
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
3689
err:
3690
	blk_mq_end_request(rq, errno_to_blk_status(result));
I
Ilya Dryomov 已提交
3691
}
A
Alex Elder 已提交
3692

3693
static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
C
Christoph Hellwig 已提交
3694
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
3695
{
C
Christoph Hellwig 已提交
3696 3697
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
3698

C
Christoph Hellwig 已提交
3699
	queue_work(rbd_wq, work);
3700
	return BLK_STS_OK;
A
Alex Elder 已提交
3701 3702
}

3703 3704
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
3705 3706 3707
	blk_cleanup_queue(rbd_dev->disk->queue);
	blk_mq_free_tag_set(&rbd_dev->tag_set);
	put_disk(rbd_dev->disk);
3708
	rbd_dev->disk = NULL;
3709 3710
}

3711
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
3712 3713 3714
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
3715 3716

{
3717 3718 3719 3720
	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);
3721 3722
	int ret;

3723 3724 3725
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
3726

3727 3728 3729
	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
3730

3731
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
3732
	if (ret)
3733
		goto out_req;
3734

3735 3736 3737 3738 3739
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
3740

3741 3742 3743 3744 3745 3746 3747 3748
	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);
3749

3750 3751
out_req:
	ceph_osdc_put_request(req);
3752 3753 3754
	return ret;
}

3755
/*
A
Alex Elder 已提交
3756 3757 3758
 * 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.
3759
 */
3760
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3761
{
3762
	struct rbd_image_header_ondisk *ondisk = NULL;
3763
	u32 snap_count = 0;
3764 3765 3766
	u64 names_size = 0;
	u32 want_count;
	int ret;
3767

A
Alex Elder 已提交
3768
	/*
3769 3770 3771 3772 3773
	 * 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
3774
	 */
3775 3776 3777 3778 3779 3780 3781 3782 3783 3784
	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
3785
			return -ENOMEM;
3786

3787 3788
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
3789
		if (ret < 0)
A
Alex Elder 已提交
3790
			goto out;
A
Alex Elder 已提交
3791
		if ((size_t)ret < size) {
3792
			ret = -ENXIO;
A
Alex Elder 已提交
3793 3794
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
3795
			goto out;
3796 3797 3798
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
3799
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
3800
			goto out;
3801
		}
3802

3803 3804 3805 3806
		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
3807

A
Alex Elder 已提交
3808 3809
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
3810 3811 3812
	kfree(ondisk);

	return ret;
3813 3814
}

3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833
/*
 * 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);
}

3834 3835 3836 3837 3838
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
3839 3840 3841
	 * 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.
3842
	 */
I
Ilya Dryomov 已提交
3843 3844
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
3845 3846 3847 3848 3849 3850 3851
		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
3852
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3853
{
3854
	u64 mapping_size;
A
Alex Elder 已提交
3855 3856
	int ret;

3857
	down_write(&rbd_dev->header_rwsem);
3858
	mapping_size = rbd_dev->mapping.size;
3859 3860

	ret = rbd_dev_header_info(rbd_dev);
3861
	if (ret)
3862
		goto out;
3863

3864 3865 3866 3867 3868 3869 3870
	/*
	 * 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)
3871
			goto out;
3872 3873
	}

3874
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
3875
		rbd_dev->mapping.size = rbd_dev->header.image_size;
3876 3877 3878 3879
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
3880

3881
out:
3882
	up_write(&rbd_dev->header_rwsem);
3883
	if (!ret && mapping_size != rbd_dev->mapping.size)
3884
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
3885

3886
	return ret;
A
Alex Elder 已提交
3887 3888
}

3889 3890
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
3891 3892 3893 3894 3895 3896 3897
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

3898
static const struct blk_mq_ops rbd_mq_ops = {
C
Christoph Hellwig 已提交
3899 3900 3901 3902
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

3903 3904 3905 3906
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
3907
	u64 segment_size;
C
Christoph Hellwig 已提交
3908
	int err;
3909 3910

	/* create gendisk info */
3911 3912 3913
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
3914
	if (!disk)
A
Alex Elder 已提交
3915
		return -ENOMEM;
3916

A
Alex Elder 已提交
3917
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
3918
		 rbd_dev->dev_id);
3919
	disk->major = rbd_dev->major;
3920
	disk->first_minor = rbd_dev->minor;
3921 3922
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
3923 3924 3925
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
3926 3927
	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
3928
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
3929
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
3930
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
3931 3932 3933 3934 3935
	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)
3936
		goto out_disk;
3937

C
Christoph Hellwig 已提交
3938 3939 3940 3941 3942 3943
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

3944 3945
	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
3946

3947
	/* set io sizes to object size */
A
Alex Elder 已提交
3948 3949
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
3950
	q->limits.max_sectors = queue_max_hw_sectors(q);
3951
	blk_queue_max_segments(q, USHRT_MAX);
3952
	blk_queue_max_segment_size(q, UINT_MAX);
A
Alex Elder 已提交
3953 3954
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
3955

3956 3957 3958
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
3959
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
3960
	blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE);
3961

3962
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
3963
		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
3964

3965 3966 3967 3968 3969
	/*
	 * 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));
3970 3971 3972 3973 3974 3975
	disk->queue = q;
	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
3976 3977
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
3978 3979
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
3980
	return err;
3981 3982
}

3983 3984 3985 3986
/*
  sysfs
*/

A
Alex Elder 已提交
3987 3988 3989 3990 3991
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

3992 3993 3994
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3995
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3996

A
Alex Elder 已提交
3997 3998
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
3999 4000
}

A
Alex Elder 已提交
4001 4002 4003 4004 4005 4006 4007 4008 4009 4010
/*
 * 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
4011
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4012 4013
}

4014 4015 4016
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4017
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4018

A
Alex Elder 已提交
4019 4020 4021 4022
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4023 4024 4025 4026 4027 4028
}

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
4029

4030
	return sprintf(buf, "%d\n", rbd_dev->minor);
4031 4032
}

4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043
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));
}

4044 4045
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4046
{
A
Alex Elder 已提交
4047
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4048

4049
	return sprintf(buf, "client%lld\n",
4050
		       ceph_client_gid(rbd_dev->rbd_client->client));
4051 4052
}

4053 4054 4055 4056 4057 4058 4059 4060
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);
}

4061 4062 4063 4064 4065 4066
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);
4067 4068
}

4069 4070
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4071
{
A
Alex Elder 已提交
4072
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4073

4074
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4075 4076
}

4077 4078 4079 4080 4081
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);

4082
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4083
			(unsigned long long) rbd_dev->spec->pool_id);
4084 4085
}

4086 4087 4088
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4089
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4090

A
Alex Elder 已提交
4091 4092 4093 4094
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4095 4096
}

A
Alex Elder 已提交
4097 4098 4099 4100 4101
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);

4102
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4103 4104
}

A
Alex Elder 已提交
4105 4106 4107 4108
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4109 4110 4111 4112
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4113
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4114

4115
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4116 4117
}

4118 4119 4120 4121 4122 4123 4124 4125
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);
}

4126
/*
4127 4128 4129
 * 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)".
4130 4131
 */
static ssize_t rbd_parent_show(struct device *dev,
4132 4133
			       struct device_attribute *attr,
			       char *buf)
4134 4135
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4136
	ssize_t count = 0;
4137

4138
	if (!rbd_dev->parent)
4139 4140
		return sprintf(buf, "(no parent image)\n");

4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156
	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;
4157 4158
}

4159 4160 4161 4162 4163
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
4164
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4165
	int ret;
4166

A
Alex Elder 已提交
4167
	ret = rbd_dev_refresh(rbd_dev);
4168
	if (ret)
4169
		return ret;
4170

4171
	return size;
4172
}
4173

4174
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4175
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4176
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4177
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4178
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4179
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4180
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4181
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4182
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4183
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4184
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4185
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4186 4187
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4188
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4189
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4190 4191 4192

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4193
	&dev_attr_features.attr,
4194
	&dev_attr_major.attr,
4195
	&dev_attr_minor.attr,
4196
	&dev_attr_client_addr.attr,
4197
	&dev_attr_client_id.attr,
4198
	&dev_attr_cluster_fsid.attr,
4199
	&dev_attr_config_info.attr,
4200
	&dev_attr_pool.attr,
4201
	&dev_attr_pool_id.attr,
4202
	&dev_attr_name.attr,
A
Alex Elder 已提交
4203
	&dev_attr_image_id.attr,
4204
	&dev_attr_current_snap.attr,
4205
	&dev_attr_snap_id.attr,
4206
	&dev_attr_parent.attr,
4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219
	&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
};

4220
static void rbd_dev_release(struct device *dev);
4221

4222
static const struct device_type rbd_device_type = {
4223 4224
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4225
	.release	= rbd_dev_release,
4226 4227
};

4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248
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;
4249 4250 4251

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267
	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);
}

4268
static void rbd_dev_free(struct rbd_device *rbd_dev)
4269
{
4270
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4271
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4272

4273
	ceph_oid_destroy(&rbd_dev->header_oid);
4274
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4275
	kfree(rbd_dev->config_info);
4276

4277 4278 4279 4280
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293
}

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);
4294 4295 4296 4297 4298 4299 4300 4301 4302 4303

	/*
	 * 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);
}

4304 4305
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4306 4307 4308
{
	struct rbd_device *rbd_dev;

4309
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4310 4311 4312 4313 4314 4315 4316
	if (!rbd_dev)
		return NULL;

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

4317
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4318
	ceph_oid_init(&rbd_dev->header_oid);
4319
	rbd_dev->header_oloc.pool = spec->pool_id;
4320

4321 4322 4323 4324
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4325 4326 4327 4328 4329 4330 4331 4332
	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);

4333 4334 4335 4336 4337
	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);

4338
	rbd_dev->rbd_client = rbdc;
4339
	rbd_dev->spec = spec;
4340

4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370
	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;
4371

4372 4373
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4374

4375
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4376
	return rbd_dev;
4377 4378 4379 4380 4381 4382

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4383 4384 4385 4386
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4387 4388
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4389 4390
}

4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405
/*
 * 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 };

4406 4407 4408 4409
	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));
4410
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4411 4412
	if (ret < 0)
		return ret;
4413 4414
	if (ret < sizeof (size_buf))
		return -ERANGE;
4415

J
Josh Durgin 已提交
4416
	if (order) {
4417
		*order = size_buf.order;
J
Josh Durgin 已提交
4418 4419
		dout("  order %u", (unsigned int)*order);
	}
4420 4421
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4422 4423
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4424
		(unsigned long long)*snap_size);
4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435

	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);
}

4436 4437 4438 4439 4440 4441 4442 4443 4444 4445
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;

4446 4447 4448
	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);
4449
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4450 4451 4452 4453 4454
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4455 4456
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469

	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;
}

4470 4471 4472 4473 4474 4475 4476
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;
4477
	} __attribute__ ((packed)) features_buf = { 0 };
4478
	u64 unsup;
4479 4480
	int ret;

4481 4482 4483 4484
	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));
4485
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4486 4487
	if (ret < 0)
		return ret;
4488 4489
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4490

4491 4492 4493 4494
	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
4495
		return -ENXIO;
4496
	}
A
Alex Elder 已提交
4497

4498 4499 4500
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4501 4502 4503
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4504 4505 4506 4507 4508 4509 4510 4511 4512 4513

	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);
}

4514 4515 4516 4517 4518 4519 4520 4521
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
4522
	u64 pool_id;
4523
	char *image_id;
4524
	u64 snap_id;
4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541
	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;
	}

4542
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4543 4544 4545
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
4546
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4547 4548 4549 4550
	if (ret < 0)
		goto out_err;

	p = reply_buf;
4551 4552
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
4553
	ceph_decode_64_safe(&p, end, pool_id, out_err);
4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570
	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);
		}

4571
		goto out;	/* No parent?  No problem. */
4572
	}
4573

4574 4575 4576
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
4577
	if (pool_id > (u64)U32_MAX) {
4578
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
4579
			(unsigned long long)pool_id, U32_MAX);
4580
		goto out_err;
A
Alex Elder 已提交
4581
	}
4582

A
Alex Elder 已提交
4583
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4584 4585 4586 4587
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
4588
	ceph_decode_64_safe(&p, end, snap_id, out_err);
4589 4590
	ceph_decode_64_safe(&p, end, overlap, out_err);

4591 4592 4593 4594 4595 4596 4597 4598 4599
	/*
	 * 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
4600 4601
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
4602 4603
	} else {
		kfree(image_id);
4604 4605 4606
	}

	/*
4607 4608
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
4609 4610 4611
	 */
	if (!overlap) {
		if (parent_spec) {
4612 4613 4614 4615
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
4616
		} else {
4617 4618
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
4619
		}
A
Alex Elder 已提交
4620
	}
4621 4622
	rbd_dev->parent_overlap = overlap;

4623 4624 4625 4626 4627 4628 4629 4630 4631
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644
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;

4645 4646 4647
	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);
4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660
	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
4661
	obj_size = rbd_obj_bytes(&rbd_dev->header);
4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675
	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;
	}
4676 4677
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
4678 4679 4680 4681

	return 0;
}

4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699
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;
}

4700 4701
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
4702
	CEPH_DEFINE_OID_ONSTACK(oid);
4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714
	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
4715 4716
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
4717 4718 4719 4720 4721
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
4722
	end = image_id + image_id_size;
4723
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
4724 4725 4726 4727 4728 4729

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

4730 4731 4732 4733
	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);
4734 4735 4736
	if (ret < 0)
		goto out;
	p = reply_buf;
4737 4738
	end = reply_buf + ret;

4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750
	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;
}

4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780
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);
4781 4782 4783 4784 4785 4786 4787
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805
		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);
}

4806
/*
4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833
 * 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.
4834
 *
4835 4836
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
4837
 */
4838
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
4839
{
4840 4841 4842 4843 4844
	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;
4845 4846
	int ret;

4847 4848 4849
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
4850

4851
	/* Get the pool name; we have to make our own copy of this */
4852

4853 4854 4855
	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);
4856 4857
		return -EIO;
	}
4858 4859
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
4860 4861 4862 4863
		return -ENOMEM;

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

4864 4865
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
4866
		rbd_warn(rbd_dev, "unable to get image name");
4867

4868
	/* Fetch the snapshot name */
4869

4870
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4871 4872
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
4873
		goto out_err;
4874 4875 4876 4877 4878
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
4879 4880

	return 0;
4881

4882
out_err:
4883 4884
	kfree(image_name);
	kfree(pool_name);
4885 4886 4887
	return ret;
}

A
Alex Elder 已提交
4888
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911
{
	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;

4912 4913 4914
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
4915
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4916 4917 4918 4919
	if (ret < 0)
		goto out;

	p = reply_buf;
4920 4921
	end = reply_buf + ret;
	ret = -ERANGE;
4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937
	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;
4938
	ret = 0;
4939

4940
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4941 4942 4943 4944 4945 4946 4947 4948
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

4949
	ceph_put_snap_context(rbd_dev->header.snapc);
4950 4951 4952
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
4953
		(unsigned long long)seq, (unsigned int)snap_count);
4954 4955 4956
out:
	kfree(reply_buf);

4957
	return ret;
4958 4959
}

4960 4961
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
4962 4963 4964
{
	size_t size;
	void *reply_buf;
4965
	__le64 snapid;
A
Alex Elder 已提交
4966 4967 4968 4969 4970 4971 4972 4973 4974 4975
	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);

4976
	snapid = cpu_to_le64(snap_id);
4977 4978 4979
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
4980
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4981 4982
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
4983
		goto out;
4984
	}
A
Alex Elder 已提交
4985 4986

	p = reply_buf;
4987
	end = reply_buf + ret;
A
Alex Elder 已提交
4988
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4989
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
4990 4991
		goto out;

4992
	dout("  snap_id 0x%016llx snap_name = %s\n",
4993
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
4994 4995 4996
out:
	kfree(reply_buf);

4997
	return snap_name;
A
Alex Elder 已提交
4998 4999
}

5000
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5001
{
5002
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5003 5004
	int ret;

5005 5006
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5007
		return ret;
5008

5009 5010 5011
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5012
			return ret;
5013 5014
	}

A
Alex Elder 已提交
5015
	ret = rbd_dev_v2_snap_context(rbd_dev);
5016 5017 5018 5019
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5020 5021 5022 5023

	return ret;
}

5024 5025 5026 5027 5028 5029 5030 5031 5032 5033
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);
}

5034 5035 5036
/*
 * 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
5037 5038
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052
 */
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
5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 5073 5074
/*
 * 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
5075
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5087
/*
5088 5089 5090 5091
 * 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
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 5120 5121 5122 5123 5124 5125 5126
 * 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.
5127
 */
5128
static int rbd_add_parse_args(const char *buf,
5129
				struct ceph_options **ceph_opts,
5130 5131
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5132
{
A
Alex Elder 已提交
5133
	size_t len;
5134
	char *options;
5135
	const char *mon_addrs;
5136
	char *snap_name;
5137
	size_t mon_addrs_size;
5138
	struct rbd_spec *spec = NULL;
5139
	struct rbd_options *rbd_opts = NULL;
5140
	struct ceph_options *copts;
5141
	int ret;
5142 5143 5144

	/* The first four tokens are required */

5145
	len = next_token(&buf);
5146 5147 5148 5149
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5150
	mon_addrs = buf;
5151
	mon_addrs_size = len + 1;
5152
	buf += len;
5153

5154
	ret = -EINVAL;
5155 5156
	options = dup_token(&buf, NULL);
	if (!options)
5157
		return -ENOMEM;
5158 5159 5160 5161
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5162

5163 5164
	spec = rbd_spec_alloc();
	if (!spec)
5165
		goto out_mem;
5166 5167 5168 5169

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5170 5171 5172 5173
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5174

A
Alex Elder 已提交
5175
	spec->image_name = dup_token(&buf, NULL);
5176
	if (!spec->image_name)
5177
		goto out_mem;
5178 5179 5180 5181
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5182

5183 5184 5185 5186
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5187
	len = next_token(&buf);
5188
	if (!len) {
5189 5190
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5191
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5192
		ret = -ENAMETOOLONG;
5193
		goto out_err;
5194
	}
5195 5196
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5197
		goto out_mem;
5198 5199
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5200

5201
	/* Initialize all rbd options to the defaults */
5202

5203 5204 5205 5206 5207
	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
5208
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5209
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
I
Ilya Dryomov 已提交
5210
	rbd_opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
A
Alex Elder 已提交
5211

5212
	copts = ceph_parse_options(options, mon_addrs,
5213
					mon_addrs + mon_addrs_size - 1,
5214
					parse_rbd_opts_token, rbd_opts);
5215 5216
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5217 5218
		goto out_err;
	}
5219 5220 5221
	kfree(options);

	*ceph_opts = copts;
5222
	*opts = rbd_opts;
5223
	*rbd_spec = spec;
5224

5225
	return 0;
5226
out_mem:
5227
	ret = -ENOMEM;
A
Alex Elder 已提交
5228
out_err:
5229 5230
	kfree(rbd_opts);
	rbd_spec_put(spec);
5231
	kfree(options);
A
Alex Elder 已提交
5232

5233
	return ret;
5234 5235
}

5236 5237 5238 5239 5240
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5241
	struct ceph_options *opts = rbdc->client->options;
5242 5243 5244 5245 5246 5247 5248
	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) {
5249 5250
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5251 5252 5253 5254
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5255
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5256
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5257 5258
						     newest_epoch,
						     opts->mount_timeout);
5259 5260 5261 5262 5263 5264 5265 5266 5267 5268
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

I
Ilya Dryomov 已提交
5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294 5295
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
5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313
/*
 * 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;
5314
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5315
	void *response;
5316
	char *image_id;
5317

A
Alex Elder 已提交
5318 5319 5320
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5321 5322
	 * 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
5323
	 */
5324 5325 5326
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5327
		return 0;
5328
	}
A
Alex Elder 已提交
5329

A
Alex Elder 已提交
5330 5331 5332 5333
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5334 5335 5336 5337 5338 5339
	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
5340 5341 5342 5343 5344 5345 5346 5347 5348 5349

	/* 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;
	}

5350 5351
	/* If it doesn't exist we'll assume it's a format 1 image */

5352 5353 5354
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5355
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5356 5357 5358 5359 5360
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5361
	} else if (ret >= 0) {
5362 5363 5364
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5365
						NULL, GFP_NOIO);
5366
		ret = PTR_ERR_OR_ZERO(image_id);
5367 5368 5369 5370 5371 5372 5373
		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
5374 5375 5376
	}
out:
	kfree(response);
5377
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5378 5379 5380
	return ret;
}

A
Alex Elder 已提交
5381 5382 5383 5384
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5385 5386 5387 5388
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5389
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5390 5391 5392 5393

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

	header = &rbd_dev->header;
5394
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5395 5396 5397 5398 5399 5400
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5401
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5402 5403 5404
{
	int ret;

5405
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5406
	if (ret)
5407 5408
		goto out_err;

5409 5410 5411 5412
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5413
	ret = rbd_dev_v2_features(rbd_dev);
5414
	if (ret)
5415
		goto out_err;
5416

5417 5418 5419 5420 5421 5422 5423
	/* 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;
	}
5424

5425 5426 5427 5428 5429 5430
	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
5431
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5432
	return 0;
I
Ilya Dryomov 已提交
5433

5434
out_err:
A
Alex Elder 已提交
5435
	rbd_dev->header.features = 0;
5436 5437
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5438
	return ret;
5439 5440
}

5441 5442 5443 5444 5445 5446
/*
 * @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
5447
{
5448
	struct rbd_device *parent = NULL;
5449 5450 5451 5452 5453
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5454 5455 5456 5457 5458 5459
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5460
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5461 5462
	if (!parent) {
		ret = -ENOMEM;
5463
		goto out_err;
5464 5465 5466 5467 5468 5469 5470 5471
	}

	/*
	 * 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);
5472

5473
	ret = rbd_dev_image_probe(parent, depth);
5474 5475
	if (ret < 0)
		goto out_err;
5476

5477
	rbd_dev->parent = parent;
5478
	atomic_set(&rbd_dev->parent_ref, 1);
5479
	return 0;
5480

5481
out_err:
5482
	rbd_dev_unparent(rbd_dev);
5483
	rbd_dev_destroy(parent);
5484 5485 5486
	return ret;
}

5487 5488 5489 5490 5491 5492 5493 5494 5495
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
5496 5497 5498 5499
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5500
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5501
{
A
Alex Elder 已提交
5502
	int ret;
A
Alex Elder 已提交
5503

5504
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5505

5506 5507 5508
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5509
			goto err_out_unlock;
5510 5511 5512 5513 5514 5515 5516

		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
5517 5518 5519 5520 5521 5522 5523

	/* Set up the blkdev mapping. */

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

5524
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5525 5526
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5527

5528
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5529
	set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only);
5530

5531
	ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
5532
	if (ret)
5533
		goto err_out_mapping;
A
Alex Elder 已提交
5534

5535
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5536
	up_write(&rbd_dev->header_rwsem);
5537
	return 0;
5538

5539 5540
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5541 5542 5543
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5544 5545
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
5546 5547
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5548 5549 5550
	return ret;
}

A
Alex Elder 已提交
5551 5552 5553
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
5554
	int ret;
A
Alex Elder 已提交
5555 5556 5557 5558 5559

	/* 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)
5560 5561
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
5562
	else
5563 5564
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
5565

5566
	return ret;
A
Alex Elder 已提交
5567 5568
}

5569 5570
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5571
	rbd_dev_unprobe(rbd_dev);
5572 5573
	if (rbd_dev->opts)
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5574 5575 5576
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5577 5578
}

5579 5580
/*
 * Probe for the existence of the header object for the given rbd
5581 5582 5583
 * 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.
5584
 */
5585
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
5586 5587 5588 5589
{
	int ret;

	/*
A
Alex Elder 已提交
5590 5591 5592 5593
	 * 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.
5594 5595 5596
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
5597 5598
		return ret;

A
Alex Elder 已提交
5599 5600 5601 5602
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

5603
	if (!depth) {
5604
		ret = rbd_register_watch(rbd_dev);
5605 5606 5607 5608 5609
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
5610
			goto err_out_format;
5611
		}
5612
	}
5613

5614
	ret = rbd_dev_header_info(rbd_dev);
5615
	if (ret)
5616
		goto err_out_watch;
A
Alex Elder 已提交
5617

5618 5619 5620 5621 5622 5623
	/*
	 * 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.
	 */
5624
	if (!depth)
5625 5626 5627
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
5628 5629 5630 5631 5632 5633
	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
5634
		goto err_out_probe;
5635
	}
5636

5637 5638 5639 5640 5641 5642 5643 5644 5645
	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.
		 */
5646
		if (!depth && rbd_dev->parent_spec)
5647 5648 5649 5650
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

5651
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
5652 5653 5654 5655
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
5656
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
5657
	return 0;
5658

A
Alex Elder 已提交
5659 5660
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
5661
err_out_watch:
5662
	if (!depth)
5663
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5664 5665
err_out_format:
	rbd_dev->image_format = 0;
5666 5667
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5668 5669 5670
	return ret;
}

5671 5672 5673
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
5674
{
5675
	struct rbd_device *rbd_dev = NULL;
5676
	struct ceph_options *ceph_opts = NULL;
5677
	struct rbd_options *rbd_opts = NULL;
5678
	struct rbd_spec *spec = NULL;
5679
	struct rbd_client *rbdc;
5680
	int rc;
5681 5682 5683 5684 5685

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

	/* parse add command */
5686
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
5687
	if (rc < 0)
5688
		goto out;
5689

5690 5691 5692
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
5693
		goto err_out_args;
5694
	}
5695 5696

	/* pick the pool */
5697
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
5698 5699 5700
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
5701
		goto err_out_client;
5702
	}
A
Alex Elder 已提交
5703
	spec->pool_id = (u64)rc;
5704

5705
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
5706 5707
	if (!rbd_dev) {
		rc = -ENOMEM;
5708
		goto err_out_client;
5709
	}
5710 5711
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
5712
	rbd_opts = NULL;	/* rbd_dev now owns this */
5713

5714 5715 5716 5717 5718 5719
	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
5720
	down_write(&rbd_dev->header_rwsem);
5721
	rc = rbd_dev_image_probe(rbd_dev, 0);
5722 5723
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
5724
		goto err_out_rbd_dev;
5725
	}
5726

5727 5728
	/* If we are mapping a snapshot it must be marked read-only */
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
5729
		rbd_dev->opts->read_only = true;
5730

5731
	rc = rbd_dev_device_setup(rbd_dev);
5732
	if (rc)
5733
		goto err_out_image_probe;
A
Alex Elder 已提交
5734

I
Ilya Dryomov 已提交
5735 5736 5737 5738
	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
5739 5740
	}

5741 5742 5743 5744
	/* Everything's ready.  Announce the disk to the world. */

	rc = device_add(&rbd_dev->dev);
	if (rc)
I
Ilya Dryomov 已提交
5745
		goto err_out_image_lock;
5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757

	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);
5758 5759 5760 5761
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
5762

I
Ilya Dryomov 已提交
5763 5764
err_out_image_lock:
	rbd_dev_image_unlock(rbd_dev);
5765 5766
err_out_device_setup:
	rbd_dev_device_release(rbd_dev);
5767 5768
err_out_image_probe:
	rbd_dev_image_release(rbd_dev);
5769 5770
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
5771
err_out_client:
5772
	rbd_put_client(rbdc);
5773
err_out_args:
5774
	rbd_spec_put(spec);
5775
	kfree(rbd_opts);
5776
	goto out;
5777 5778
}

5779 5780 5781 5782 5783 5784 5785 5786 5787 5788 5789 5790 5791 5792 5793 5794 5795
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);
}

5796 5797
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5798
	while (rbd_dev->parent) {
5799 5800 5801 5802 5803 5804 5805 5806 5807 5808 5809 5810
		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
5811
		rbd_assert(second);
5812
		rbd_dev_image_release(second);
5813
		rbd_dev_destroy(second);
A
Alex Elder 已提交
5814 5815 5816 5817
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
5818 5819 5820 5821 5822
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

5823 5824 5825
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
5826 5827
{
	struct rbd_device *rbd_dev = NULL;
5828 5829
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
5830
	char opt_buf[6];
5831
	bool already = false;
M
Mike Christie 已提交
5832
	bool force = false;
5833
	int ret;
5834

M
Mike Christie 已提交
5835 5836 5837 5838 5839
	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");
5840
		return -EINVAL;
M
Mike Christie 已提交
5841 5842 5843 5844 5845 5846 5847 5848 5849
	}
	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;
		}
	}
5850

5851 5852 5853 5854 5855 5856 5857 5858
	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;
		}
5859
	}
5860 5861
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
5862
		if (rbd_dev->open_count && !force)
5863 5864
			ret = -EBUSY;
		else
5865 5866
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
5867 5868 5869
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
5870
	if (ret < 0 || already)
5871
		return ret;
5872

M
Mike Christie 已提交
5873 5874 5875 5876 5877 5878 5879 5880 5881
	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);
	}

5882 5883 5884 5885 5886
	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);
5887

I
Ilya Dryomov 已提交
5888
	rbd_dev_image_unlock(rbd_dev);
5889
	rbd_dev_device_release(rbd_dev);
5890
	rbd_dev_image_release(rbd_dev);
5891
	rbd_dev_destroy(rbd_dev);
5892
	return count;
5893 5894
}

5895 5896 5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909 5910 5911
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);
}

5912 5913
/*
 * create control files in sysfs
5914
 * /sys/bus/rbd/...
5915 5916 5917
 */
static int rbd_sysfs_init(void)
{
5918
	int ret;
5919

5920
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
5921
	if (ret < 0)
5922
		return ret;
5923

5924 5925 5926
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
5927 5928 5929 5930 5931 5932

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
5933
	bus_unregister(&rbd_bus_type);
5934
	device_unregister(&rbd_root_dev);
5935 5936
}

5937 5938 5939
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
5940
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
5941 5942 5943 5944
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
5945
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
5946 5947 5948
	if (!rbd_obj_request_cache)
		goto out_err;

5949
	return 0;
5950

5951
out_err:
5952 5953
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
5954 5955 5956 5957 5958
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
5959 5960 5961 5962
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

5963 5964 5965 5966 5967
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
5968
static int __init rbd_init(void)
5969 5970 5971
{
	int rc;

5972 5973 5974 5975
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
5976

5977
	rc = rbd_slab_init();
5978 5979
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
5980

5981 5982
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
5983
	 * rbd devices * queue depth, so leave @max_active at default.
5984 5985 5986 5987 5988 5989 5990
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

5991 5992 5993 5994
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
5995
			goto err_out_wq;
5996 5997 5998
		}
	}

5999 6000
	rc = rbd_sysfs_init();
	if (rc)
6001 6002 6003 6004 6005 6006
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6007

I
Ilya Dryomov 已提交
6008 6009
	return 0;

6010 6011 6012
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6013 6014
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6015 6016
err_out_slab:
	rbd_slab_exit();
6017
	return rc;
6018 6019
}

A
Alex Elder 已提交
6020
static void __exit rbd_exit(void)
6021
{
I
Ilya Dryomov 已提交
6022
	ida_destroy(&rbd_dev_id_ida);
6023
	rbd_sysfs_cleanup();
6024 6025
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6026
	destroy_workqueue(rbd_wq);
6027
	rbd_slab_exit();
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}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6033
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>");

6039
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6040
MODULE_LICENSE("GPL");