rbd.c 149.8 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/striper.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;

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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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	OBJ_REQUEST_OWN_BVECS,	/* private bio_vec array, doesn't own pages */
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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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/*
 * 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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	struct ceph_object_extent ex;
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	union {
		bool			tried_parent;	/* for reads */
		enum rbd_obj_write_state write_state;	/* for writes */
	};
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	struct rbd_img_request	*img_request;
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	struct ceph_file_extent	*img_extents;
	u32			num_img_extents;
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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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			u32			bvec_idx;
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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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	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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	enum obj_request_type	data_type;
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	unsigned long		flags;
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	union {
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		u64			snap_id;	/* for reads */
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		struct ceph_snap_context *snapc;	/* for writes */
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	};
	union {
		struct request		*rq;		/* block request */
		struct rbd_obj_request	*obj_request;	/* obj req initiator */
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	};
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	spinlock_t		completion_lock;
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	u64			xferred;/* aggregate bytes transferred */
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	int			result;	/* first nonzero obj_request result */
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	struct list_head	object_extents;	/* obj_req.ex structs */
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	u32			obj_request_count;
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	u32			pending_count;
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	struct kref		kref;
};

#define for_each_obj_request(ireq, oreq) \
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	list_for_each_entry(oreq, &(ireq)->object_extents, ex.oe_item)
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#define for_each_obj_request_safe(ireq, oreq, n) \
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	list_for_each_entry_safe(oreq, n, &(ireq)->object_extents, ex.oe_item)
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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 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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static int rbd_dev_refresh(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
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static int rbd_dev_header_info(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
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static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id);
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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);
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static int rbd_open(struct block_device *bdev, fmode_t mode)
{
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	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
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	bool removing = false;
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	spin_lock_irq(&rbd_dev->lock);
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	if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
		removing = true;
	else
		rbd_dev->open_count++;
589
	spin_unlock_irq(&rbd_dev->lock);
590 591 592
	if (removing)
		return -ENOENT;

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593
	(void) get_device(&rbd_dev->dev);
594

595 596 597
	return 0;
}

598
static void rbd_release(struct gendisk *disk, fmode_t mode)
599 600
{
	struct rbd_device *rbd_dev = disk->private_data;
601 602
	unsigned long open_count_before;

603
	spin_lock_irq(&rbd_dev->lock);
604
	open_count_before = rbd_dev->open_count--;
605
	spin_unlock_irq(&rbd_dev->lock);
606
	rbd_assert(open_count_before > 0);
607

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608
	put_device(&rbd_dev->dev);
609 610
}

G
Guangliang Zhao 已提交
611 612
static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
613
	int ro;
G
Guangliang Zhao 已提交
614

615
	if (get_user(ro, (int __user *)arg))
G
Guangliang Zhao 已提交
616 617
		return -EFAULT;

618
	/* Snapshots can't be marked read-write */
G
Guangliang Zhao 已提交
619 620 621
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
		return -EROFS;

622 623
	/* Let blkdev_roset() handle it */
	return -ENOTTY;
G
Guangliang Zhao 已提交
624 625 626 627 628 629
}

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;
630
	int ret;
G
Guangliang Zhao 已提交
631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650

	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 */

651 652 653
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
654
	.release		= rbd_release,
G
Guangliang Zhao 已提交
655 656 657 658
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
659 660 661
};

/*
662
 * Initialize an rbd client instance.  Success or not, this function
663
 * consumes ceph_opts.  Caller holds client_mutex.
664
 */
665
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
666 667 668 669
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

A
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670
	dout("%s:\n", __func__);
671 672 673 674 675 676 677
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

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

678
	rbdc->client = ceph_create_client(ceph_opts, rbdc);
679
	if (IS_ERR(rbdc->client))
680
		goto out_rbdc;
A
Alex Elder 已提交
681
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
682 683 684

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
685
		goto out_client;
686

A
Alex Elder 已提交
687
	spin_lock(&rbd_client_list_lock);
688
	list_add_tail(&rbdc->node, &rbd_client_list);
A
Alex Elder 已提交
689
	spin_unlock(&rbd_client_list_lock);
690

A
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691
	dout("%s: rbdc %p\n", __func__, rbdc);
692

693
	return rbdc;
694
out_client:
695
	ceph_destroy_client(rbdc->client);
696
out_rbdc:
697 698
	kfree(rbdc);
out_opt:
A
Alex Elder 已提交
699 700
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
A
Alex Elder 已提交
701 702
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
703
	return ERR_PTR(ret);
704 705
}

706 707 708 709 710 711 712
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

713
/*
714 715
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
716
 */
717
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
718 719
{
	struct rbd_client *client_node;
720
	bool found = false;
721

A
Alex Elder 已提交
722
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
723 724
		return NULL;

725 726 727
	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)) {
728 729
			__rbd_get_client(client_node);

730 731 732 733 734 735 736
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
737 738
}

739
/*
740
 * (Per device) rbd map options
741 742
 */
enum {
I
Ilya Dryomov 已提交
743
	Opt_queue_depth,
744 745 746 747
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
A
Alex Elder 已提交
748 749
	Opt_read_only,
	Opt_read_write,
I
Ilya Dryomov 已提交
750
	Opt_lock_on_read,
I
Ilya Dryomov 已提交
751
	Opt_exclusive,
752
	Opt_err
753 754
};

A
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755
static match_table_t rbd_opts_tokens = {
I
Ilya Dryomov 已提交
756
	{Opt_queue_depth, "queue_depth=%d"},
757 758
	/* int args above */
	/* string args above */
A
Alex Elder 已提交
759
	{Opt_read_only, "read_only"},
A
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760 761 762
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
I
Ilya Dryomov 已提交
763
	{Opt_lock_on_read, "lock_on_read"},
I
Ilya Dryomov 已提交
764
	{Opt_exclusive, "exclusive"},
765
	{Opt_err, NULL}
766 767
};

A
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768
struct rbd_options {
I
Ilya Dryomov 已提交
769
	int	queue_depth;
A
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770
	bool	read_only;
I
Ilya Dryomov 已提交
771
	bool	lock_on_read;
I
Ilya Dryomov 已提交
772
	bool	exclusive;
A
Alex Elder 已提交
773 774
};

I
Ilya Dryomov 已提交
775
#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
A
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776
#define RBD_READ_ONLY_DEFAULT	false
I
Ilya Dryomov 已提交
777
#define RBD_LOCK_ON_READ_DEFAULT false
I
Ilya Dryomov 已提交
778
#define RBD_EXCLUSIVE_DEFAULT	false
A
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779

780 781
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
782
	struct rbd_options *rbd_opts = private;
783 784 785
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
Alex Elder 已提交
786
	token = match_token(c, rbd_opts_tokens, argstr);
787 788 789
	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
790
			pr_err("bad mount option arg (not int) at '%s'\n", c);
791 792 793 794
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
795
		dout("got string token %d val %s\n", token, argstr[0].from);
796 797 798 799 800
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
I
Ilya Dryomov 已提交
801 802 803 804 805 806 807
	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
808 809 810 811 812 813
	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
814 815 816
	case Opt_lock_on_read:
		rbd_opts->lock_on_read = true;
		break;
I
Ilya Dryomov 已提交
817 818 819
	case Opt_exclusive:
		rbd_opts->exclusive = true;
		break;
820
	default:
821 822
		/* libceph prints "bad option" msg */
		return -EINVAL;
823
	}
824

825 826 827
	return 0;
}

G
Guangliang Zhao 已提交
828 829 830 831 832 833 834
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";
835 836
	case OBJ_OP_DISCARD:
		return "discard";
G
Guangliang Zhao 已提交
837 838 839 840 841
	default:
		return "???";
	}
}

842 843
/*
 * Destroy ceph client
A
Alex Elder 已提交
844
 *
A
Alex Elder 已提交
845
 * Caller must hold rbd_client_list_lock.
846 847 848 849 850
 */
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
851
	dout("%s: rbdc %p\n", __func__, rbdc);
852
	spin_lock(&rbd_client_list_lock);
853
	list_del(&rbdc->node);
854
	spin_unlock(&rbd_client_list_lock);
855 856 857 858 859 860 861 862 863

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

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
864
static void rbd_put_client(struct rbd_client *rbdc)
865
{
866 867
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
868 869
}

870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886
static int wait_for_latest_osdmap(struct ceph_client *client)
{
	u64 newest_epoch;
	int ret;

	ret = ceph_monc_get_version(&client->monc, "osdmap", &newest_epoch);
	if (ret)
		return ret;

	if (client->osdc.osdmap->epoch >= newest_epoch)
		return 0;

	ceph_osdc_maybe_request_map(&client->osdc);
	return ceph_monc_wait_osdmap(&client->monc, newest_epoch,
				     client->options->mount_timeout);
}

887 888 889 890 891 892 893 894
/*
 * Get a ceph client with specific addr and configuration, if one does
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
 */
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
{
	struct rbd_client *rbdc;
895
	int ret;
896 897 898

	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
	rbdc = rbd_client_find(ceph_opts);
899
	if (rbdc) {
900
		ceph_destroy_options(ceph_opts);
901 902 903 904 905 906 907 908 909 910 911 912

		/*
		 * Using an existing client.  Make sure ->pg_pools is up to
		 * date before we look up the pool id in do_rbd_add().
		 */
		ret = wait_for_latest_osdmap(rbdc->client);
		if (ret) {
			rbd_warn(NULL, "failed to get latest osdmap: %d", ret);
			rbd_put_client(rbdc);
			rbdc = ERR_PTR(ret);
		}
	} else {
913
		rbdc = rbd_client_create(ceph_opts);
914
	}
915 916 917 918 919
	mutex_unlock(&client_mutex);

	return rbdc;
}

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
}

1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
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);
	}));
}

1260 1261 1262 1263 1264 1265 1266 1267
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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/*
 * Zero a range in @obj_req data buffer defined by a bio (list) or
1272
 * (private) bio_vec array.
I
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1273 1274 1275 1276 1277 1278
 *
 * @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)
{
1279
	switch (obj_req->img_request->data_type) {
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	case OBJ_REQUEST_BIO:
		zero_bios(&obj_req->bio_pos, off, bytes);
		break;
	case OBJ_REQUEST_BVECS:
1284
	case OBJ_REQUEST_OWN_BVECS:
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		zero_bvecs(&obj_req->bvec_pos, off, bytes);
		break;
	default:
		rbd_assert(0);
	}
}

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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,
1297
		kref_read(&obj_request->kref));
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	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1301 1302 1303
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
1304
	     kref_read(&img_request->kref));
1305 1306 1307
	kref_get(&img_request->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,
1313
		kref_read(&img_request->kref));
1314
	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)
{
1320 1321
	rbd_assert(obj_request->img_request == NULL);

1322
	/* Image request now owns object's original reference */
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1323
	obj_request->img_request = img_request;
1324
	img_request->obj_request_count++;
I
Ilya Dryomov 已提交
1325
	img_request->pending_count++;
1326
	dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
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1327 1328 1329 1330 1331
}

static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1332
	dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1333
	list_del(&obj_request->ex.oe_item);
1334 1335
	rbd_assert(img_request->obj_request_count > 0);
	img_request->obj_request_count--;
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	rbd_assert(obj_request->img_request == img_request);
	rbd_obj_request_put(obj_request);
}

1340
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
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1341
{
1342 1343
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1344
	dout("%s %p object_no %016llx %llu~%llu osd_req %p\n", __func__,
1345 1346
	     obj_request, obj_request->ex.oe_objno, obj_request->ex.oe_off,
	     obj_request->ex.oe_len, osd_req);
1347
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
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1348 1349
}

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1350 1351 1352 1353 1354
/*
 * 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.
 */
1355 1356 1357 1358 1359 1360
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1361 1362 1363 1364 1365 1366
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1367 1368 1369 1370 1371 1372
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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1373 1374 1375 1376
static bool rbd_obj_is_entire(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;

1377 1378
	return !obj_req->ex.oe_off &&
	       obj_req->ex.oe_len == rbd_dev->layout.object_size;
I
Ilya Dryomov 已提交
1379 1380 1381 1382 1383 1384
}

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

1385
	return obj_req->ex.oe_off + obj_req->ex.oe_len ==
I
Ilya Dryomov 已提交
1386 1387 1388
					rbd_dev->layout.object_size;
}

I
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1389 1390 1391 1392 1393 1394
static u64 rbd_obj_img_extents_bytes(struct rbd_obj_request *obj_req)
{
	return ceph_file_extents_bytes(obj_req->img_extents,
				       obj_req->num_img_extents);
}

I
Ilya Dryomov 已提交
1395 1396
static bool rbd_img_is_write(struct rbd_img_request *img_req)
{
I
Ilya Dryomov 已提交
1397
	switch (img_req->op_type) {
I
Ilya Dryomov 已提交
1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409
	case OBJ_OP_READ:
		return false;
	case OBJ_OP_WRITE:
	case OBJ_OP_DISCARD:
		return true;
	default:
		rbd_assert(0);
	}
}

static void rbd_obj_handle_request(struct rbd_obj_request *obj_req);

1410
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
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1411
{
I
Ilya Dryomov 已提交
1412
	struct rbd_obj_request *obj_req = osd_req->r_priv;
A
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1413

I
Ilya Dryomov 已提交
1414 1415 1416
	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);
1417

I
Ilya Dryomov 已提交
1418 1419 1420 1421 1422 1423 1424 1425 1426 1427
	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;
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I
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1429
	rbd_obj_handle_request(obj_req);
A
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1430 1431
}

1432
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
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1433
{
1434
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
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1435

1436
	osd_req->r_flags = CEPH_OSD_FLAG_READ;
1437
	osd_req->r_snapid = obj_request->img_request->snap_id;
1438 1439 1440 1441 1442 1443
}

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

1444
	osd_req->r_flags = CEPH_OSD_FLAG_WRITE;
1445
	ktime_get_real_ts(&osd_req->r_mtime);
1446
	osd_req->r_data_offset = obj_request->ex.oe_off;
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1447 1448
}

1449
static struct ceph_osd_request *
1450
rbd_osd_req_create(struct rbd_obj_request *obj_req, unsigned int num_ops)
1451
{
1452 1453
	struct rbd_img_request *img_req = obj_req->img_request;
	struct rbd_device *rbd_dev = img_req->rbd_dev;
1454 1455
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_osd_request *req;
1456 1457
	const char *name_format = rbd_dev->image_format == 1 ?
				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
1458

1459 1460 1461
	req = ceph_osdc_alloc_request(osdc,
			(rbd_img_is_write(img_req) ? img_req->snapc : NULL),
			num_ops, false, GFP_NOIO);
1462 1463 1464 1465
	if (!req)
		return NULL;

	req->r_callback = rbd_osd_req_callback;
1466
	req->r_priv = obj_req;
1467 1468

	req->r_base_oloc.pool = rbd_dev->layout.pool_id;
1469
	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
1470
			rbd_dev->header.object_prefix, obj_req->ex.oe_objno))
1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482
		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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1483 1484 1485 1486 1487
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

1488
static struct rbd_obj_request *rbd_obj_request_create(void)
A
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1489 1490 1491
{
	struct rbd_obj_request *obj_request;

1492
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
1493
	if (!obj_request)
1494 1495
		return NULL;

1496
	ceph_object_extent_init(&obj_request->ex);
A
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1497 1498
	kref_init(&obj_request->kref);

1499
	dout("%s %p\n", __func__, obj_request);
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1500 1501 1502 1503 1504 1505
	return obj_request;
}

static void rbd_obj_request_destroy(struct kref *kref)
{
	struct rbd_obj_request *obj_request;
1506
	u32 i;
A
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1507 1508 1509

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

A
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1510 1511
	dout("%s: obj %p\n", __func__, obj_request);

A
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1512 1513 1514
	if (obj_request->osd_req)
		rbd_osd_req_destroy(obj_request->osd_req);

1515
	switch (obj_request->img_request->data_type) {
1516
	case OBJ_REQUEST_NODATA:
A
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1517
	case OBJ_REQUEST_BIO:
1518
	case OBJ_REQUEST_BVECS:
1519
		break;		/* Nothing to do */
1520 1521 1522
	case OBJ_REQUEST_OWN_BVECS:
		kfree(obj_request->bvec_pos.bvecs);
		break;
1523 1524
	default:
		rbd_assert(0);
A
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1525 1526
	}

I
Ilya Dryomov 已提交
1527
	kfree(obj_request->img_extents);
1528 1529 1530 1531 1532 1533 1534
	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);
	}
1535

1536
	kmem_cache_free(rbd_obj_request_cache, obj_request);
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1537 1538
}

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1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549
/* 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;
}

1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571
/*
 * 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
1572
		rbd_warn(rbd_dev, "parent reference underflow");
1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584
}

/*
 * 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)
{
1585
	int counter = 0;
1586 1587 1588 1589

	if (!rbd_dev->parent_spec)
		return false;

1590 1591 1592 1593
	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);
1594 1595

	if (counter < 0)
1596
		rbd_warn(rbd_dev, "parent reference overflow");
1597

1598
	return counter > 0;
1599 1600
}

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1601 1602 1603 1604 1605
/*
 * 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
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1606 1607
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1608
					enum obj_operation_type op_type,
1609
					struct ceph_snap_context *snapc)
A
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1610 1611 1612
{
	struct rbd_img_request *img_request;

1613
	img_request = kmem_cache_zalloc(rbd_img_request_cache, GFP_NOIO);
A
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1614 1615 1616 1617
	if (!img_request)
		return NULL;

	img_request->rbd_dev = rbd_dev;
I
Ilya Dryomov 已提交
1618 1619
	img_request->op_type = op_type;
	if (!rbd_img_is_write(img_request))
A
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1620
		img_request->snap_id = rbd_dev->spec->snap_id;
I
Ilya Dryomov 已提交
1621 1622 1623
	else
		img_request->snapc = snapc;

1624
	if (rbd_dev_parent_get(rbd_dev))
1625
		img_request_layered_set(img_request);
1626

A
Alex Elder 已提交
1627
	spin_lock_init(&img_request->completion_lock);
1628
	INIT_LIST_HEAD(&img_request->object_extents);
A
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1629 1630
	kref_init(&img_request->kref);

1631 1632
	dout("%s: rbd_dev %p %s -> img %p\n", __func__, rbd_dev,
	     obj_op_name(op_type), img_request);
A
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1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
	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
1644 1645
	dout("%s: img %p\n", __func__, img_request);

A
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1646 1647
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
1648
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
1649

1650 1651 1652 1653 1654
	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
1655
	if (rbd_img_is_write(img_request))
1656
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
1657

1658
	kmem_cache_free(rbd_img_request_cache, img_request);
A
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1659 1660
}

I
Ilya Dryomov 已提交
1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707
static void prune_extents(struct ceph_file_extent *img_extents,
			  u32 *num_img_extents, u64 overlap)
{
	u32 cnt = *num_img_extents;

	/* drop extents completely beyond the overlap */
	while (cnt && img_extents[cnt - 1].fe_off >= overlap)
		cnt--;

	if (cnt) {
		struct ceph_file_extent *ex = &img_extents[cnt - 1];

		/* trim final overlapping extent */
		if (ex->fe_off + ex->fe_len > overlap)
			ex->fe_len = overlap - ex->fe_off;
	}

	*num_img_extents = cnt;
}

/*
 * Determine the byte range(s) covered by either just the object extent
 * or the entire object in the parent image.
 */
static int rbd_obj_calc_img_extents(struct rbd_obj_request *obj_req,
				    bool entire)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
	int ret;

	if (!rbd_dev->parent_overlap)
		return 0;

	ret = ceph_extent_to_file(&rbd_dev->layout, obj_req->ex.oe_objno,
				  entire ? 0 : obj_req->ex.oe_off,
				  entire ? rbd_dev->layout.object_size :
							obj_req->ex.oe_len,
				  &obj_req->img_extents,
				  &obj_req->num_img_extents);
	if (ret)
		return ret;

	prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
		      rbd_dev->parent_overlap);
	return 0;
}

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static void rbd_osd_req_setup_data(struct rbd_obj_request *obj_req, u32 which)
{
1710
	switch (obj_req->img_request->data_type) {
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	case OBJ_REQUEST_BIO:
		osd_req_op_extent_osd_data_bio(obj_req->osd_req, which,
					       &obj_req->bio_pos,
1714
					       obj_req->ex.oe_len);
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		break;
	case OBJ_REQUEST_BVECS:
1717
	case OBJ_REQUEST_OWN_BVECS:
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		rbd_assert(obj_req->bvec_pos.iter.bi_size ==
1719
							obj_req->ex.oe_len);
1720
		rbd_assert(obj_req->bvec_idx == obj_req->bvec_count);
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		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)
{
1731
	obj_req->osd_req = rbd_osd_req_create(obj_req, 1);
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	if (!obj_req->osd_req)
		return -ENOMEM;

	osd_req_op_extent_init(obj_req->osd_req, 0, CEPH_OSD_OP_READ,
1736
			       obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
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	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,
1783
			       obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
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	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;

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	/* reverse map the entire object onto the parent */
	ret = rbd_obj_calc_img_extents(obj_req, true);
	if (ret)
		return ret;

	if (obj_req->num_img_extents) {
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		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 */
	}

1808
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
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	if (!obj_req->osd_req)
		return -ENOMEM;

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	if (obj_req->num_img_extents) {
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		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)) {
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		if (obj_req->num_img_extents) {
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			osd_req_op_init(obj_req->osd_req, which++,
					CEPH_OSD_OP_CREATE, 0);
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			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,
1845
				       obj_req->ex.oe_off, obj_req->ex.oe_len,
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				       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;

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	/* reverse map the entire object onto the parent */
	ret = rbd_obj_calc_img_extents(obj_req, true);
	if (ret)
		return ret;

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	if (rbd_obj_is_entire(obj_req)) {
		obj_req->write_state = RBD_OBJ_WRITE_FLAT;
1864 1865 1866 1867
		if (obj_req->num_img_extents)
			num_osd_ops = 2; /* create + truncate */
		else
			num_osd_ops = 1; /* delete */
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	} else {
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		if (obj_req->num_img_extents) {
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			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 */
		}
	}

1878
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
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	if (!obj_req->osd_req)
		return -ENOMEM;

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	if (!rbd_obj_is_entire(obj_req) && obj_req->num_img_extents) {
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		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) {
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		switch (img_req->op_type) {
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		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;
}

1923 1924 1925 1926 1927 1928 1929 1930 1931 1932
union rbd_img_fill_iter {
	struct ceph_bio_iter	bio_iter;
	struct ceph_bvec_iter	bvec_iter;
};

struct rbd_img_fill_ctx {
	enum obj_request_type	pos_type;
	union rbd_img_fill_iter	*pos;
	union rbd_img_fill_iter	iter;
	ceph_object_extent_fn_t	set_pos_fn;
1933 1934
	ceph_object_extent_fn_t	count_fn;
	ceph_object_extent_fn_t	copy_fn;
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
};

static struct ceph_object_extent *alloc_object_extent(void *arg)
{
	struct rbd_img_request *img_req = arg;
	struct rbd_obj_request *obj_req;

	obj_req = rbd_obj_request_create();
	if (!obj_req)
		return NULL;

	rbd_img_obj_request_add(img_req, obj_req);
	return &obj_req->ex;
}

1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990
/*
 * While su != os && sc == 1 is technically not fancy (it's the same
 * layout as su == os && sc == 1), we can't use the nocopy path for it
 * because ->set_pos_fn() should be called only once per object.
 * ceph_file_to_extents() invokes action_fn once per stripe unit, so
 * treat su != os && sc == 1 as fancy.
 */
static bool rbd_layout_is_fancy(struct ceph_file_layout *l)
{
	return l->stripe_unit != l->object_size;
}

static int rbd_img_fill_request_nocopy(struct rbd_img_request *img_req,
				       struct ceph_file_extent *img_extents,
				       u32 num_img_extents,
				       struct rbd_img_fill_ctx *fctx)
{
	u32 i;
	int ret;

	img_req->data_type = fctx->pos_type;

	/*
	 * Create object requests and set each object request's starting
	 * position in the provided bio (list) or bio_vec array.
	 */
	fctx->iter = *fctx->pos;
	for (i = 0; i < num_img_extents; i++) {
		ret = ceph_file_to_extents(&img_req->rbd_dev->layout,
					   img_extents[i].fe_off,
					   img_extents[i].fe_len,
					   &img_req->object_extents,
					   alloc_object_extent, img_req,
					   fctx->set_pos_fn, &fctx->iter);
		if (ret)
			return ret;
	}

	return __rbd_img_fill_request(img_req);
}

1991 1992 1993 1994
/*
 * Map a list of image extents to a list of object extents, create the
 * corresponding object requests (normally each to a different object,
 * but not always) and add them to @img_req.  For each object request,
1995
 * set up its data descriptor to point to the corresponding chunk(s) of
1996 1997
 * @fctx->pos data buffer.
 *
1998 1999 2000 2001
 * Because ceph_file_to_extents() will merge adjacent object extents
 * together, each object request's data descriptor may point to multiple
 * different chunks of @fctx->pos data buffer.
 *
2002 2003 2004 2005 2006 2007 2008
 * @fctx->pos data buffer is assumed to be large enough.
 */
static int rbd_img_fill_request(struct rbd_img_request *img_req,
				struct ceph_file_extent *img_extents,
				u32 num_img_extents,
				struct rbd_img_fill_ctx *fctx)
{
2009 2010
	struct rbd_device *rbd_dev = img_req->rbd_dev;
	struct rbd_obj_request *obj_req;
2011 2012 2013
	u32 i;
	int ret;

2014 2015 2016 2017 2018 2019
	if (fctx->pos_type == OBJ_REQUEST_NODATA ||
	    !rbd_layout_is_fancy(&rbd_dev->layout))
		return rbd_img_fill_request_nocopy(img_req, img_extents,
						   num_img_extents, fctx);

	img_req->data_type = OBJ_REQUEST_OWN_BVECS;
2020 2021

	/*
2022 2023 2024 2025 2026
	 * Create object requests and determine ->bvec_count for each object
	 * request.  Note that ->bvec_count sum over all object requests may
	 * be greater than the number of bio_vecs in the provided bio (list)
	 * or bio_vec array because when mapped, those bio_vecs can straddle
	 * stripe unit boundaries.
2027 2028 2029
	 */
	fctx->iter = *fctx->pos;
	for (i = 0; i < num_img_extents; i++) {
2030
		ret = ceph_file_to_extents(&rbd_dev->layout,
2031 2032 2033 2034
					   img_extents[i].fe_off,
					   img_extents[i].fe_len,
					   &img_req->object_extents,
					   alloc_object_extent, img_req,
2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
					   fctx->count_fn, &fctx->iter);
		if (ret)
			return ret;
	}

	for_each_obj_request(img_req, obj_req) {
		obj_req->bvec_pos.bvecs = kmalloc_array(obj_req->bvec_count,
					      sizeof(*obj_req->bvec_pos.bvecs),
					      GFP_NOIO);
		if (!obj_req->bvec_pos.bvecs)
			return -ENOMEM;
	}

	/*
	 * Fill in each object request's private bio_vec array, splitting and
	 * rearranging the provided bio_vecs in stripe unit chunks as needed.
	 */
	fctx->iter = *fctx->pos;
	for (i = 0; i < num_img_extents; i++) {
		ret = ceph_iterate_extents(&rbd_dev->layout,
					   img_extents[i].fe_off,
					   img_extents[i].fe_len,
					   &img_req->object_extents,
					   fctx->copy_fn, &fctx->iter);
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
		if (ret)
			return ret;
	}

	return __rbd_img_fill_request(img_req);
}

static int rbd_img_fill_nodata(struct rbd_img_request *img_req,
			       u64 off, u64 len)
{
	struct ceph_file_extent ex = { off, len };
	union rbd_img_fill_iter dummy;
	struct rbd_img_fill_ctx fctx = {
		.pos_type = OBJ_REQUEST_NODATA,
		.pos = &dummy,
	};

	return rbd_img_fill_request(img_req, &ex, 1, &fctx);
}

static void set_bio_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
{
	struct rbd_obj_request *obj_req =
	    container_of(ex, struct rbd_obj_request, ex);
	struct ceph_bio_iter *it = arg;

	dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
	obj_req->bio_pos = *it;
	ceph_bio_iter_advance(it, bytes);
}

2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115
static void count_bio_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
{
	struct rbd_obj_request *obj_req =
	    container_of(ex, struct rbd_obj_request, ex);
	struct ceph_bio_iter *it = arg;

	dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
	ceph_bio_iter_advance_step(it, bytes, ({
		obj_req->bvec_count++;
	}));

}

static void copy_bio_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
{
	struct rbd_obj_request *obj_req =
	    container_of(ex, struct rbd_obj_request, ex);
	struct ceph_bio_iter *it = arg;

	dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
	ceph_bio_iter_advance_step(it, bytes, ({
		obj_req->bvec_pos.bvecs[obj_req->bvec_idx++] = bv;
		obj_req->bvec_pos.iter.bi_size += bv.bv_len;
	}));
}

2116 2117 2118 2119 2120 2121 2122 2123 2124
static int __rbd_img_fill_from_bio(struct rbd_img_request *img_req,
				   struct ceph_file_extent *img_extents,
				   u32 num_img_extents,
				   struct ceph_bio_iter *bio_pos)
{
	struct rbd_img_fill_ctx fctx = {
		.pos_type = OBJ_REQUEST_BIO,
		.pos = (union rbd_img_fill_iter *)bio_pos,
		.set_pos_fn = set_bio_pos,
2125 2126
		.count_fn = count_bio_bvecs,
		.copy_fn = copy_bio_bvecs,
2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152
	};

	return rbd_img_fill_request(img_req, img_extents, num_img_extents,
				    &fctx);
}

static int rbd_img_fill_from_bio(struct rbd_img_request *img_req,
				 u64 off, u64 len, struct bio *bio)
{
	struct ceph_file_extent ex = { off, len };
	struct ceph_bio_iter it = { .bio = bio, .iter = bio->bi_iter };

	return __rbd_img_fill_from_bio(img_req, &ex, 1, &it);
}

static void set_bvec_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
{
	struct rbd_obj_request *obj_req =
	    container_of(ex, struct rbd_obj_request, ex);
	struct ceph_bvec_iter *it = arg;

	obj_req->bvec_pos = *it;
	ceph_bvec_iter_shorten(&obj_req->bvec_pos, bytes);
	ceph_bvec_iter_advance(it, bytes);
}

2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175
static void count_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
{
	struct rbd_obj_request *obj_req =
	    container_of(ex, struct rbd_obj_request, ex);
	struct ceph_bvec_iter *it = arg;

	ceph_bvec_iter_advance_step(it, bytes, ({
		obj_req->bvec_count++;
	}));
}

static void copy_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
{
	struct rbd_obj_request *obj_req =
	    container_of(ex, struct rbd_obj_request, ex);
	struct ceph_bvec_iter *it = arg;

	ceph_bvec_iter_advance_step(it, bytes, ({
		obj_req->bvec_pos.bvecs[obj_req->bvec_idx++] = bv;
		obj_req->bvec_pos.iter.bi_size += bv.bv_len;
	}));
}

2176 2177 2178 2179 2180 2181 2182 2183 2184
static int __rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
				     struct ceph_file_extent *img_extents,
				     u32 num_img_extents,
				     struct ceph_bvec_iter *bvec_pos)
{
	struct rbd_img_fill_ctx fctx = {
		.pos_type = OBJ_REQUEST_BVECS,
		.pos = (union rbd_img_fill_iter *)bvec_pos,
		.set_pos_fn = set_bvec_pos,
2185 2186
		.count_fn = count_bvecs,
		.copy_fn = copy_bvecs,
2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207
	};

	return rbd_img_fill_request(img_req, img_extents, num_img_extents,
				    &fctx);
}

static int rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
				   struct ceph_file_extent *img_extents,
				   u32 num_img_extents,
				   struct bio_vec *bvecs)
{
	struct ceph_bvec_iter it = {
		.bvecs = bvecs,
		.iter = { .bi_size = ceph_file_extents_bytes(img_extents,
							     num_img_extents) },
	};

	return __rbd_img_fill_from_bvecs(img_req, img_extents, num_img_extents,
					 &it);
}

2208
static void rbd_img_request_submit(struct rbd_img_request *img_request)
A
Alex Elder 已提交
2209 2210 2211
{
	struct rbd_obj_request *obj_request;

A
Alex Elder 已提交
2212
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
2213

2214
	rbd_img_request_get(img_request);
2215
	for_each_obj_request(img_request, obj_request)
I
Ilya Dryomov 已提交
2216
		rbd_obj_request_submit(obj_request);
A
Alex Elder 已提交
2217

2218
	rbd_img_request_put(img_request);
A
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2219
}
A
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2220

I
Ilya Dryomov 已提交
2221
static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
I
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2222 2223 2224 2225 2226
{
	struct rbd_img_request *img_req = obj_req->img_request;
	struct rbd_img_request *child_img_req;
	int ret;

2227 2228
	child_img_req = rbd_img_request_create(img_req->rbd_dev->parent,
					       OBJ_OP_READ, NULL);
I
Ilya Dryomov 已提交
2229 2230 2231
	if (!child_img_req)
		return -ENOMEM;

2232 2233 2234
	__set_bit(IMG_REQ_CHILD, &child_img_req->flags);
	child_img_req->obj_request = obj_req;

I
Ilya Dryomov 已提交
2235
	if (!rbd_img_is_write(img_req)) {
2236
		switch (img_req->data_type) {
I
Ilya Dryomov 已提交
2237
		case OBJ_REQUEST_BIO:
2238 2239 2240 2241
			ret = __rbd_img_fill_from_bio(child_img_req,
						      obj_req->img_extents,
						      obj_req->num_img_extents,
						      &obj_req->bio_pos);
I
Ilya Dryomov 已提交
2242 2243
			break;
		case OBJ_REQUEST_BVECS:
2244
		case OBJ_REQUEST_OWN_BVECS:
2245 2246 2247 2248
			ret = __rbd_img_fill_from_bvecs(child_img_req,
						      obj_req->img_extents,
						      obj_req->num_img_extents,
						      &obj_req->bvec_pos);
I
Ilya Dryomov 已提交
2249 2250 2251 2252 2253
			break;
		default:
			rbd_assert(0);
		}
	} else {
2254 2255 2256 2257
		ret = rbd_img_fill_from_bvecs(child_img_req,
					      obj_req->img_extents,
					      obj_req->num_img_extents,
					      obj_req->copyup_bvecs);
I
Ilya Dryomov 已提交
2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273
	}
	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 &&
I
Ilya Dryomov 已提交
2274 2275 2276
	    rbd_dev->parent_overlap && !obj_req->tried_parent) {
		/* reverse map this object extent onto the parent */
		ret = rbd_obj_calc_img_extents(obj_req, false);
I
Ilya Dryomov 已提交
2277 2278 2279 2280
		if (ret) {
			obj_req->result = ret;
			return true;
		}
I
Ilya Dryomov 已提交
2281 2282 2283 2284 2285 2286 2287 2288 2289 2290

		if (obj_req->num_img_extents) {
			obj_req->tried_parent = true;
			ret = rbd_obj_read_from_parent(obj_req);
			if (ret) {
				obj_req->result = ret;
				return true;
			}
			return false;
		}
I
Ilya Dryomov 已提交
2291 2292 2293 2294 2295 2296 2297 2298 2299
	}

	/*
	 * -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 ||
2300
	    (!obj_req->result && obj_req->xferred < obj_req->ex.oe_len)) {
I
Ilya Dryomov 已提交
2301 2302
		rbd_assert(!obj_req->xferred || !obj_req->result);
		rbd_obj_zero_range(obj_req, obj_req->xferred,
2303
				   obj_req->ex.oe_len - obj_req->xferred);
I
Ilya Dryomov 已提交
2304
		obj_req->result = 0;
2305
		obj_req->xferred = obj_req->ex.oe_len;
I
Ilya Dryomov 已提交
2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341
	}

	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).
	 */
2342
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
I
Ilya Dryomov 已提交
2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360
	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);

I
Ilya Dryomov 已提交
2361
	switch (obj_req->img_request->op_type) {
I
Ilya Dryomov 已提交
2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376
	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);
	return 0;
}

2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404
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;
}

I
Ilya Dryomov 已提交
2405 2406 2407 2408 2409
static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
	int ret;

I
Ilya Dryomov 已提交
2410 2411 2412 2413
	rbd_assert(obj_req->num_img_extents);
	prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
		      rbd_dev->parent_overlap);
	if (!obj_req->num_img_extents) {
I
Ilya Dryomov 已提交
2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426
		/*
		 * 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);
	}

I
Ilya Dryomov 已提交
2427
	ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));
I
Ilya Dryomov 已提交
2428 2429 2430 2431
	if (ret)
		return ret;

	obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
I
Ilya Dryomov 已提交
2432
	return rbd_obj_read_from_parent(obj_req);
I
Ilya Dryomov 已提交
2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462
}

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.
			 */
2463
			obj_req->xferred = obj_req->ex.oe_len;
I
Ilya Dryomov 已提交
2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486
		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)
{
I
Ilya Dryomov 已提交
2487
	switch (obj_req->img_request->op_type) {
I
Ilya Dryomov 已提交
2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499
	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;
2500
				obj_req->xferred = obj_req->ex.oe_len;
I
Ilya Dryomov 已提交
2501 2502 2503 2504 2505 2506 2507 2508 2509
			}
			return true;
		}
		return false;
	default:
		rbd_assert(0);
	}
}

I
Ilya Dryomov 已提交
2510 2511 2512 2513 2514
static void rbd_obj_end_request(struct rbd_obj_request *obj_req)
{
	struct rbd_img_request *img_req = obj_req->img_request;

	rbd_assert((!obj_req->result &&
2515
		    obj_req->xferred == obj_req->ex.oe_len) ||
I
Ilya Dryomov 已提交
2516 2517 2518 2519 2520 2521 2522 2523
		   (obj_req->result < 0 && !obj_req->xferred));
	if (!obj_req->result) {
		img_req->xferred += obj_req->xferred;
		return;
	}

	rbd_warn(img_req->rbd_dev,
		 "%s at objno %llu %llu~%llu result %d xferred %llu",
2524 2525
		 obj_op_name(img_req->op_type), obj_req->ex.oe_objno,
		 obj_req->ex.oe_off, obj_req->ex.oe_len, obj_req->result,
I
Ilya Dryomov 已提交
2526 2527 2528 2529 2530 2531 2532
		 obj_req->xferred);
	if (!img_req->result) {
		img_req->result = obj_req->result;
		img_req->xferred = 0;
	}
}

I
Ilya Dryomov 已提交
2533 2534 2535 2536 2537
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));
I
Ilya Dryomov 已提交
2538 2539 2540
	rbd_assert((!img_req->result &&
		    img_req->xferred == rbd_obj_img_extents_bytes(obj_req)) ||
		   (img_req->result < 0 && !img_req->xferred));
I
Ilya Dryomov 已提交
2541 2542 2543 2544

	obj_req->result = img_req->result;
	obj_req->xferred = img_req->xferred;
	rbd_img_request_put(img_req);
I
Ilya Dryomov 已提交
2545
}
I
Ilya Dryomov 已提交
2546

I
Ilya Dryomov 已提交
2547 2548 2549 2550 2551 2552 2553 2554 2555 2556
static void rbd_img_end_request(struct rbd_img_request *img_req)
{
	rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags));
	rbd_assert((!img_req->result &&
		    img_req->xferred == blk_rq_bytes(img_req->rq)) ||
		   (img_req->result < 0 && !img_req->xferred));

	blk_mq_end_request(img_req->rq,
			   errno_to_blk_status(img_req->result));
	rbd_img_request_put(img_req);
I
Ilya Dryomov 已提交
2557 2558 2559 2560
}

static void rbd_obj_handle_request(struct rbd_obj_request *obj_req)
{
I
Ilya Dryomov 已提交
2561 2562 2563
	struct rbd_img_request *img_req;

again:
I
Ilya Dryomov 已提交
2564 2565 2566
	if (!__rbd_obj_handle_request(obj_req))
		return;

I
Ilya Dryomov 已提交
2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582
	img_req = obj_req->img_request;
	spin_lock(&img_req->completion_lock);
	rbd_obj_end_request(obj_req);
	rbd_assert(img_req->pending_count);
	if (--img_req->pending_count) {
		spin_unlock(&img_req->completion_lock);
		return;
	}

	spin_unlock(&img_req->completion_lock);
	if (test_bit(IMG_REQ_CHILD, &img_req->flags)) {
		obj_req = img_req->obj_request;
		rbd_img_end_child_request(img_req);
		goto again;
	}
	rbd_img_end_request(img_req);
I
Ilya Dryomov 已提交
2583 2584
}

2585
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
2586

2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622
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);
}

2623 2624 2625 2626 2627 2628 2629 2630 2631
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);
}

2632 2633 2634 2635
/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
2636
{
2637
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2638
	char cookie[32];
2639
	int ret;
A
Alex Elder 已提交
2640

I
Ilya Dryomov 已提交
2641 2642
	WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] != '\0');
2643

2644 2645 2646 2647
	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);
2648
	if (ret)
2649
		return ret;
A
Alex Elder 已提交
2650

2651
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
2652
	__rbd_lock(rbd_dev, cookie);
2653
	return 0;
A
Alex Elder 已提交
2654 2655
}

2656 2657 2658
/*
 * lock_rwsem must be held for write
 */
I
Ilya Dryomov 已提交
2659
static void rbd_unlock(struct rbd_device *rbd_dev)
2660
{
2661
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2662 2663
	int ret;

I
Ilya Dryomov 已提交
2664 2665
	WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] == '\0');
2666

2667
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
I
Ilya Dryomov 已提交
2668
			      RBD_LOCK_NAME, rbd_dev->lock_cookie);
I
Ilya Dryomov 已提交
2669 2670
	if (ret && ret != -ENOENT)
		rbd_warn(rbd_dev, "failed to unlock: %d", ret);
2671

I
Ilya Dryomov 已提交
2672 2673
	/* treat errors as the image is unlocked */
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
I
Ilya Dryomov 已提交
2674
	rbd_dev->lock_cookie[0] = '\0';
2675 2676
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
2677 2678
}

2679 2680 2681 2682
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)
2683 2684
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2685 2686 2687 2688
	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;
2689

2690
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
2691

2692 2693 2694 2695 2696
	/* 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);
2697

2698 2699 2700
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
2701 2702
}

2703 2704
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
2705
{
2706 2707
	struct page **reply_pages;
	size_t reply_len;
2708

2709 2710 2711
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
2712

2713 2714 2715 2716
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
2717

2718
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
2719 2720
}

2721
static void rbd_notify_released_lock(struct work_struct *work)
2722
{
2723 2724
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
2725

2726
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
2727 2728
}

2729
static int rbd_request_lock(struct rbd_device *rbd_dev)
2730
{
2731 2732 2733
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
2734 2735
	int ret;

2736
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
2737

2738 2739 2740 2741
	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);
2742
		goto out;
2743
	}
2744

2745 2746 2747 2748
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
2749

2750 2751 2752 2753
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
2754

2755 2756
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
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 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989
			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;
2990
	int ret = 0;
2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005

	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
3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017
	} 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);
		}
3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045
	} 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);
3046
	/*
3047
	 * Ensure that all in-flight IO is flushed.
3048
	 *
3049 3050
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3051
	 */
3052 3053 3054 3055 3056 3057 3058 3059 3060
	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
3061 3062 3063 3064 3065 3066 3067 3068 3069
	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);
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 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149
	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);
}

3150 3151 3152 3153 3154 3155
/*
 * 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)
3156 3157 3158
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
3159
	int result = 1;
3160 3161 3162 3163 3164 3165 3166 3167 3168

	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))
3169
		return result;
3170 3171

	down_read(&rbd_dev->lock_rwsem);
3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183
	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
3184 3185 3186 3187 3188 3189 3190 3191 3192
			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;
			}
3193 3194
		}
	}
3195 3196

out_unlock:
3197
	up_read(&rbd_dev->lock_rwsem);
3198
	return result;
3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218
}

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
3219

3220 3221
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3222
				   buf, buf_size);
3223
	if (ret)
3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246
		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;
3247
	u8 struct_v = 0;
3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280
	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:
3281 3282
		ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
		if (ret <= 0)
3283
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
3284
						      cookie, ret);
3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302
		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
3303 3304
}

3305 3306
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3307
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3308
{
3309
	struct rbd_device *rbd_dev = arg;
3310

3311
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3312

3313 3314 3315 3316
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3317 3318 3319 3320
	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;
3321

3322
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3323
	}
3324
	mutex_unlock(&rbd_dev->watch_mutex);
3325 3326
}

3327
/*
3328
 * watch_mutex must be locked
3329
 */
3330
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3331 3332
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3333
	struct ceph_osd_linger_request *handle;
3334

3335
	rbd_assert(!rbd_dev->watch_handle);
3336
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3337

3338 3339 3340 3341 3342
	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);
3343

3344
	rbd_dev->watch_handle = handle;
3345 3346 3347
	return 0;
}

3348 3349 3350 3351
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3352
{
3353 3354
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3355

3356 3357
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3358

3359 3360 3361
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3362

3363
	rbd_dev->watch_handle = NULL;
3364 3365
}

3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384
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)
3385
{
3386 3387 3388
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3389 3390 3391 3392
	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);
3393 3394 3395 3396
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3397
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3398 3399 3400 3401 3402 3403 3404
	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
3405 3406

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3407 3408
}

3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437
/*
 * 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 {
3438
		__rbd_lock(rbd_dev, cookie);
3439 3440 3441
	}
}

3442 3443 3444 3445 3446 3447 3448 3449 3450
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);
3451 3452
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
3453
		return;
3454
	}
3455 3456 3457 3458

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3459
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3460
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
3461
			wake_requests(rbd_dev, true);
3462
		} else {
3463 3464 3465
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3466 3467
		}
		mutex_unlock(&rbd_dev->watch_mutex);
3468
		return;
3469 3470 3471 3472 3473 3474
	}

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

3475 3476 3477 3478 3479
	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);

3480 3481 3482 3483 3484
	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
}

3485
/*
3486 3487
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3488 3489
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3490 3491
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3492
			     const char *method_name,
3493
			     const void *outbound,
3494
			     size_t outbound_size,
3495
			     void *inbound,
3496
			     size_t inbound_size)
3497
{
3498 3499 3500
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3501 3502 3503
	int ret;

	/*
3504 3505 3506 3507 3508
	 * 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.
3509
	 */
3510 3511 3512
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3513

3514 3515 3516
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3517

3518
		memcpy(page_address(req_page), outbound, outbound_size);
3519
	}
3520

3521 3522 3523 3524 3525 3526
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3527

3528 3529 3530 3531 3532 3533 3534
	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;
	}
3535

3536 3537 3538
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
3539 3540 3541
	return ret;
}

3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560
/*
 * 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);
3561 3562 3563
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

3564 3565 3566
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
3567
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
3568
{
C
Christoph Hellwig 已提交
3569 3570
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
3571
	struct rbd_img_request *img_request;
3572
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
3573 3574
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
3575
	enum obj_operation_type op_type;
3576
	u64 mapping_size;
I
Ilya Dryomov 已提交
3577
	bool must_be_locked;
A
Alex Elder 已提交
3578 3579
	int result;

3580 3581
	switch (req_op(rq)) {
	case REQ_OP_DISCARD:
3582
	case REQ_OP_WRITE_ZEROES:
3583
		op_type = OBJ_OP_DISCARD;
3584 3585
		break;
	case REQ_OP_WRITE:
G
Guangliang Zhao 已提交
3586
		op_type = OBJ_OP_WRITE;
3587 3588
		break;
	case REQ_OP_READ:
G
Guangliang Zhao 已提交
3589
		op_type = OBJ_OP_READ;
3590 3591 3592 3593 3594 3595
		break;
	default:
		dout("%s: non-fs request type %d\n", __func__, req_op(rq));
		result = -EIO;
		goto err;
	}
G
Guangliang Zhao 已提交
3596

I
Ilya Dryomov 已提交
3597
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
3598

I
Ilya Dryomov 已提交
3599 3600 3601 3602 3603
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
3604

3605 3606
	rbd_assert(op_type == OBJ_OP_READ ||
		   rbd_dev->spec->snap_id == CEPH_NOSNAP);
A
Alex Elder 已提交
3607

I
Ilya Dryomov 已提交
3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619
	/*
	 * 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
3620

I
Ilya Dryomov 已提交
3621 3622 3623 3624 3625 3626
	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
3627

C
Christoph Hellwig 已提交
3628 3629
	blk_mq_start_request(rq);

3630 3631
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
3632
	if (op_type != OBJ_OP_READ) {
3633 3634 3635 3636 3637 3638
		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
3639
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
3640
			 length, mapping_size);
I
Ilya Dryomov 已提交
3641 3642 3643
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
3644

I
Ilya Dryomov 已提交
3645 3646 3647
	must_be_locked =
	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
3648 3649
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
3650
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
I
Ilya Dryomov 已提交
3651 3652 3653 3654 3655 3656
		    !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;
			}
3657
			rbd_wait_state_locked(rbd_dev);
I
Ilya Dryomov 已提交
3658
		}
3659 3660 3661 3662
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
3663 3664
	}

3665
	img_request = rbd_img_request_create(rbd_dev, op_type, snapc);
I
Ilya Dryomov 已提交
3666 3667
	if (!img_request) {
		result = -ENOMEM;
3668
		goto err_unlock;
I
Ilya Dryomov 已提交
3669 3670
	}
	img_request->rq = rq;
3671
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
3672

3673
	if (op_type == OBJ_OP_DISCARD)
3674 3675 3676 3677
		result = rbd_img_fill_nodata(img_request, offset, length);
	else
		result = rbd_img_fill_from_bio(img_request, offset, length,
					       rq->bio);
I
Ilya Dryomov 已提交
3678 3679
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3680

3681
	rbd_img_request_submit(img_request);
3682 3683
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3684
	return;
A
Alex Elder 已提交
3685

I
Ilya Dryomov 已提交
3686 3687
err_img_request:
	rbd_img_request_put(img_request);
3688 3689 3690
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3691 3692 3693
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
3694
			 obj_op_name(op_type), length, offset, result);
3695
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
3696
err:
3697
	blk_mq_end_request(rq, errno_to_blk_status(result));
I
Ilya Dryomov 已提交
3698
}
A
Alex Elder 已提交
3699

3700
static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
C
Christoph Hellwig 已提交
3701
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
3702
{
C
Christoph Hellwig 已提交
3703 3704
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
3705

C
Christoph Hellwig 已提交
3706
	queue_work(rbd_wq, work);
3707
	return BLK_STS_OK;
A
Alex Elder 已提交
3708 3709
}

3710 3711
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
3712 3713 3714
	blk_cleanup_queue(rbd_dev->disk->queue);
	blk_mq_free_tag_set(&rbd_dev->tag_set);
	put_disk(rbd_dev->disk);
3715
	rbd_dev->disk = NULL;
3716 3717
}

3718
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
3719 3720 3721
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
3722 3723

{
3724 3725 3726 3727
	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);
3728 3729
	int ret;

3730 3731 3732
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
3733

3734 3735 3736
	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
3737

3738
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
3739
	if (ret)
3740
		goto out_req;
3741

3742 3743 3744 3745 3746
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
3747

3748 3749 3750 3751 3752 3753 3754 3755
	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);
3756

3757 3758
out_req:
	ceph_osdc_put_request(req);
3759 3760 3761
	return ret;
}

3762
/*
A
Alex Elder 已提交
3763 3764 3765
 * 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.
3766
 */
3767
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3768
{
3769
	struct rbd_image_header_ondisk *ondisk = NULL;
3770
	u32 snap_count = 0;
3771 3772 3773
	u64 names_size = 0;
	u32 want_count;
	int ret;
3774

A
Alex Elder 已提交
3775
	/*
3776 3777 3778 3779 3780
	 * 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
3781
	 */
3782 3783 3784 3785 3786 3787 3788 3789 3790 3791
	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
3792
			return -ENOMEM;
3793

3794 3795
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
3796
		if (ret < 0)
A
Alex Elder 已提交
3797
			goto out;
A
Alex Elder 已提交
3798
		if ((size_t)ret < size) {
3799
			ret = -ENXIO;
A
Alex Elder 已提交
3800 3801
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
3802
			goto out;
3803 3804 3805
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
3806
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
3807
			goto out;
3808
		}
3809

3810 3811 3812 3813
		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
3814

A
Alex Elder 已提交
3815 3816
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
3817 3818 3819
	kfree(ondisk);

	return ret;
3820 3821
}

3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840
/*
 * 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);
}

3841 3842 3843 3844 3845
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
3846 3847 3848
	 * 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.
3849
	 */
I
Ilya Dryomov 已提交
3850 3851
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
3852 3853 3854 3855 3856 3857 3858
		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
3859
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3860
{
3861
	u64 mapping_size;
A
Alex Elder 已提交
3862 3863
	int ret;

3864
	down_write(&rbd_dev->header_rwsem);
3865
	mapping_size = rbd_dev->mapping.size;
3866 3867

	ret = rbd_dev_header_info(rbd_dev);
3868
	if (ret)
3869
		goto out;
3870

3871 3872 3873 3874 3875 3876 3877
	/*
	 * 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)
3878
			goto out;
3879 3880
	}

3881
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
3882
		rbd_dev->mapping.size = rbd_dev->header.image_size;
3883 3884 3885 3886
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
3887

3888
out:
3889
	up_write(&rbd_dev->header_rwsem);
3890
	if (!ret && mapping_size != rbd_dev->mapping.size)
3891
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
3892

3893
	return ret;
A
Alex Elder 已提交
3894 3895
}

3896 3897
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
3898 3899 3900 3901 3902 3903 3904
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

3905
static const struct blk_mq_ops rbd_mq_ops = {
C
Christoph Hellwig 已提交
3906 3907 3908 3909
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

3910 3911 3912 3913
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
3914
	u64 segment_size;
C
Christoph Hellwig 已提交
3915
	int err;
3916 3917

	/* create gendisk info */
3918 3919 3920
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
3921
	if (!disk)
A
Alex Elder 已提交
3922
		return -ENOMEM;
3923

A
Alex Elder 已提交
3924
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
3925
		 rbd_dev->dev_id);
3926
	disk->major = rbd_dev->major;
3927
	disk->first_minor = rbd_dev->minor;
3928 3929
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
3930 3931 3932
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
3933 3934
	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
3935
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
3936
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
3937
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
3938 3939 3940 3941 3942
	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)
3943
		goto out_disk;
3944

C
Christoph Hellwig 已提交
3945 3946 3947 3948 3949 3950
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

3951 3952
	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
3953

3954
	/* set io sizes to object size */
A
Alex Elder 已提交
3955 3956
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
3957
	q->limits.max_sectors = queue_max_hw_sectors(q);
3958
	blk_queue_max_segments(q, USHRT_MAX);
3959
	blk_queue_max_segment_size(q, UINT_MAX);
A
Alex Elder 已提交
3960 3961
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
3962

3963 3964 3965
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
3966
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
3967
	blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE);
3968

3969
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
3970
		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
3971

3972 3973 3974 3975 3976
	/*
	 * 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));
3977 3978 3979 3980 3981 3982
	disk->queue = q;
	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
3983 3984
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
3985 3986
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
3987
	return err;
3988 3989
}

3990 3991 3992 3993
/*
  sysfs
*/

A
Alex Elder 已提交
3994 3995 3996 3997 3998
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

3999 4000 4001
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4002
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4003

A
Alex Elder 已提交
4004 4005
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4006 4007
}

A
Alex Elder 已提交
4008 4009 4010 4011 4012 4013 4014 4015 4016 4017
/*
 * 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
4018
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4019 4020
}

4021 4022 4023
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4024
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4025

A
Alex Elder 已提交
4026 4027 4028 4029
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4030 4031 4032 4033 4034 4035
}

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
4036

4037
	return sprintf(buf, "%d\n", rbd_dev->minor);
4038 4039
}

4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050
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));
}

4051 4052
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4053
{
A
Alex Elder 已提交
4054
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4055

4056
	return sprintf(buf, "client%lld\n",
4057
		       ceph_client_gid(rbd_dev->rbd_client->client));
4058 4059
}

4060 4061 4062 4063 4064 4065 4066 4067
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);
}

4068 4069 4070 4071 4072 4073
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);
4074 4075
}

4076 4077
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4078
{
A
Alex Elder 已提交
4079
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4080

4081
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4082 4083
}

4084 4085 4086 4087 4088
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);

4089
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4090
			(unsigned long long) rbd_dev->spec->pool_id);
4091 4092
}

4093 4094 4095
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4096
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4097

A
Alex Elder 已提交
4098 4099 4100 4101
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4102 4103
}

A
Alex Elder 已提交
4104 4105 4106 4107 4108
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);

4109
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4110 4111
}

A
Alex Elder 已提交
4112 4113 4114 4115
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4116 4117 4118 4119
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4120
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4121

4122
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4123 4124
}

4125 4126 4127 4128 4129 4130 4131 4132
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);
}

4133
/*
4134 4135 4136
 * 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)".
4137 4138
 */
static ssize_t rbd_parent_show(struct device *dev,
4139 4140
			       struct device_attribute *attr,
			       char *buf)
4141 4142
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4143
	ssize_t count = 0;
4144

4145
	if (!rbd_dev->parent)
4146 4147
		return sprintf(buf, "(no parent image)\n");

4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163
	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;
4164 4165
}

4166 4167 4168 4169 4170
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
4171
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4172
	int ret;
4173

A
Alex Elder 已提交
4174
	ret = rbd_dev_refresh(rbd_dev);
4175
	if (ret)
4176
		return ret;
4177

4178
	return size;
4179
}
4180

4181
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4182
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4183
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4184
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4185
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4186
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4187
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4188
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4189
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4190
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4191
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4192
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4193 4194
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4195
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4196
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4197 4198 4199

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4200
	&dev_attr_features.attr,
4201
	&dev_attr_major.attr,
4202
	&dev_attr_minor.attr,
4203
	&dev_attr_client_addr.attr,
4204
	&dev_attr_client_id.attr,
4205
	&dev_attr_cluster_fsid.attr,
4206
	&dev_attr_config_info.attr,
4207
	&dev_attr_pool.attr,
4208
	&dev_attr_pool_id.attr,
4209
	&dev_attr_name.attr,
A
Alex Elder 已提交
4210
	&dev_attr_image_id.attr,
4211
	&dev_attr_current_snap.attr,
4212
	&dev_attr_snap_id.attr,
4213
	&dev_attr_parent.attr,
4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226
	&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
};

4227
static void rbd_dev_release(struct device *dev);
4228

4229
static const struct device_type rbd_device_type = {
4230 4231
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4232
	.release	= rbd_dev_release,
4233 4234
};

4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255
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;
4256 4257 4258

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274
	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);
}

4275
static void rbd_dev_free(struct rbd_device *rbd_dev)
4276
{
4277
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4278
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4279

4280
	ceph_oid_destroy(&rbd_dev->header_oid);
4281
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4282
	kfree(rbd_dev->config_info);
4283

4284 4285 4286 4287
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300
}

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);
4301 4302 4303 4304 4305 4306 4307 4308 4309 4310

	/*
	 * 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);
}

4311 4312
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4313 4314 4315
{
	struct rbd_device *rbd_dev;

4316
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4317 4318 4319 4320 4321 4322 4323
	if (!rbd_dev)
		return NULL;

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

4324
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4325
	ceph_oid_init(&rbd_dev->header_oid);
4326
	rbd_dev->header_oloc.pool = spec->pool_id;
4327

4328 4329 4330 4331
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4332 4333 4334 4335 4336 4337 4338 4339
	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);

4340 4341 4342 4343 4344
	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);

4345
	rbd_dev->rbd_client = rbdc;
4346
	rbd_dev->spec = spec;
4347

4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377
	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;
4378

4379 4380
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4381

4382
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4383
	return rbd_dev;
4384 4385 4386 4387 4388 4389

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4390 4391 4392 4393
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4394 4395
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4396 4397
}

4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412
/*
 * 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 };

4413 4414 4415 4416
	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));
4417
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4418 4419
	if (ret < 0)
		return ret;
4420 4421
	if (ret < sizeof (size_buf))
		return -ERANGE;
4422

J
Josh Durgin 已提交
4423
	if (order) {
4424
		*order = size_buf.order;
J
Josh Durgin 已提交
4425 4426
		dout("  order %u", (unsigned int)*order);
	}
4427 4428
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4429 4430
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4431
		(unsigned long long)*snap_size);
4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442

	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);
}

4443 4444 4445 4446 4447 4448 4449 4450 4451 4452
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;

4453 4454 4455
	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);
4456
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4457 4458 4459 4460 4461
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4462 4463
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476

	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;
}

4477 4478 4479 4480 4481 4482 4483
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;
4484
	} __attribute__ ((packed)) features_buf = { 0 };
4485
	u64 unsup;
4486 4487
	int ret;

4488 4489 4490 4491
	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));
4492
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4493 4494
	if (ret < 0)
		return ret;
4495 4496
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4497

4498 4499 4500 4501
	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
4502
		return -ENXIO;
4503
	}
A
Alex Elder 已提交
4504

4505 4506 4507
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4508 4509 4510
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4511 4512 4513 4514 4515 4516 4517 4518 4519 4520

	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);
}

4521 4522 4523 4524 4525 4526 4527 4528
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
4529
	u64 pool_id;
4530
	char *image_id;
4531
	u64 snap_id;
4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548
	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;
	}

4549
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4550 4551 4552
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
4553
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4554 4555 4556 4557
	if (ret < 0)
		goto out_err;

	p = reply_buf;
4558 4559
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
4560
	ceph_decode_64_safe(&p, end, pool_id, out_err);
4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577
	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);
		}

4578
		goto out;	/* No parent?  No problem. */
4579
	}
4580

4581 4582 4583
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
4584
	if (pool_id > (u64)U32_MAX) {
4585
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
4586
			(unsigned long long)pool_id, U32_MAX);
4587
		goto out_err;
A
Alex Elder 已提交
4588
	}
4589

A
Alex Elder 已提交
4590
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4591 4592 4593 4594
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
4595
	ceph_decode_64_safe(&p, end, snap_id, out_err);
4596 4597
	ceph_decode_64_safe(&p, end, overlap, out_err);

4598 4599 4600 4601 4602 4603 4604 4605 4606
	/*
	 * 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
4607 4608
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
4609 4610
	} else {
		kfree(image_id);
4611 4612 4613
	}

	/*
4614 4615
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
4616 4617 4618
	 */
	if (!overlap) {
		if (parent_spec) {
4619 4620 4621 4622
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
4623
		} else {
4624 4625
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
4626
		}
A
Alex Elder 已提交
4627
	}
4628 4629
	rbd_dev->parent_overlap = overlap;

4630 4631 4632 4633 4634 4635 4636 4637 4638
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

4639 4640 4641 4642 4643 4644 4645 4646 4647 4648
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;
	int ret;

4649 4650 4651
	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);
4652 4653 4654 4655 4656 4657 4658
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
	if (ret < 0)
		return ret;
	if (ret < size)
		return -ERANGE;

	p = &striping_info_buf;
I
Ilya Dryomov 已提交
4659 4660
	rbd_dev->header.stripe_unit = ceph_decode_64(&p);
	rbd_dev->header.stripe_count = ceph_decode_64(&p);
4661 4662 4663
	return 0;
}

4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681
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;
}

4682 4683
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
4684
	CEPH_DEFINE_OID_ONSTACK(oid);
4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696
	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
4697 4698
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
4699 4700 4701 4702 4703
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
4704
	end = image_id + image_id_size;
4705
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
4706 4707 4708 4709 4710 4711

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

4712 4713 4714 4715
	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);
4716 4717 4718
	if (ret < 0)
		goto out;
	p = reply_buf;
4719 4720
	end = reply_buf + ret;

4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732
	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;
}

4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762
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);
4763 4764 4765 4766 4767 4768 4769
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787
		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);
}

4788
/*
4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815
 * 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.
4816
 *
4817 4818
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
4819
 */
4820
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
4821
{
4822 4823 4824 4825 4826
	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;
4827 4828
	int ret;

4829 4830 4831
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
4832

4833
	/* Get the pool name; we have to make our own copy of this */
4834

4835 4836 4837
	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);
4838 4839
		return -EIO;
	}
4840 4841
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
4842 4843 4844 4845
		return -ENOMEM;

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

4846 4847
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
4848
		rbd_warn(rbd_dev, "unable to get image name");
4849

4850
	/* Fetch the snapshot name */
4851

4852
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4853 4854
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
4855
		goto out_err;
4856 4857 4858 4859 4860
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
4861 4862

	return 0;
4863

4864
out_err:
4865 4866
	kfree(image_name);
	kfree(pool_name);
4867 4868 4869
	return ret;
}

A
Alex Elder 已提交
4870
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893
{
	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;

4894 4895 4896
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
4897
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4898 4899 4900 4901
	if (ret < 0)
		goto out;

	p = reply_buf;
4902 4903
	end = reply_buf + ret;
	ret = -ERANGE;
4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919
	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;
4920
	ret = 0;
4921

4922
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4923 4924 4925 4926 4927 4928 4929 4930
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

4931
	ceph_put_snap_context(rbd_dev->header.snapc);
4932 4933 4934
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
4935
		(unsigned long long)seq, (unsigned int)snap_count);
4936 4937 4938
out:
	kfree(reply_buf);

4939
	return ret;
4940 4941
}

4942 4943
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
4944 4945 4946
{
	size_t size;
	void *reply_buf;
4947
	__le64 snapid;
A
Alex Elder 已提交
4948 4949 4950 4951 4952 4953 4954 4955 4956 4957
	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);

4958
	snapid = cpu_to_le64(snap_id);
4959 4960 4961
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
4962
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4963 4964
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
4965
		goto out;
4966
	}
A
Alex Elder 已提交
4967 4968

	p = reply_buf;
4969
	end = reply_buf + ret;
A
Alex Elder 已提交
4970
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4971
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
4972 4973
		goto out;

4974
	dout("  snap_id 0x%016llx snap_name = %s\n",
4975
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
4976 4977 4978
out:
	kfree(reply_buf);

4979
	return snap_name;
A
Alex Elder 已提交
4980 4981
}

4982
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4983
{
4984
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
4985 4986
	int ret;

4987 4988
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
4989
		return ret;
4990

4991 4992 4993
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
4994
			return ret;
4995 4996
	}

A
Alex Elder 已提交
4997
	ret = rbd_dev_v2_snap_context(rbd_dev);
4998 4999 5000 5001
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5002 5003 5004 5005

	return ret;
}

5006 5007 5008 5009 5010 5011 5012 5013 5014 5015
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);
}

5016 5017 5018
/*
 * 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
5019 5020
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034
 */
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
5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056
/*
 * 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
5057
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5069
/*
5070 5071 5072 5073
 * 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
5074
 *
5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107 5108
 * 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.
5109
 */
5110
static int rbd_add_parse_args(const char *buf,
5111
				struct ceph_options **ceph_opts,
5112 5113
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5114
{
A
Alex Elder 已提交
5115
	size_t len;
5116
	char *options;
5117
	const char *mon_addrs;
5118
	char *snap_name;
5119
	size_t mon_addrs_size;
5120
	struct rbd_spec *spec = NULL;
5121
	struct rbd_options *rbd_opts = NULL;
5122
	struct ceph_options *copts;
5123
	int ret;
5124 5125 5126

	/* The first four tokens are required */

5127
	len = next_token(&buf);
5128 5129 5130 5131
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5132
	mon_addrs = buf;
5133
	mon_addrs_size = len + 1;
5134
	buf += len;
5135

5136
	ret = -EINVAL;
5137 5138
	options = dup_token(&buf, NULL);
	if (!options)
5139
		return -ENOMEM;
5140 5141 5142 5143
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5144

5145 5146
	spec = rbd_spec_alloc();
	if (!spec)
5147
		goto out_mem;
5148 5149 5150 5151

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5152 5153 5154 5155
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5156

A
Alex Elder 已提交
5157
	spec->image_name = dup_token(&buf, NULL);
5158
	if (!spec->image_name)
5159
		goto out_mem;
5160 5161 5162 5163
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5164

5165 5166 5167 5168
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5169
	len = next_token(&buf);
5170
	if (!len) {
5171 5172
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5173
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5174
		ret = -ENAMETOOLONG;
5175
		goto out_err;
5176
	}
5177 5178
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5179
		goto out_mem;
5180 5181
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5182

5183
	/* Initialize all rbd options to the defaults */
5184

5185 5186 5187 5188 5189
	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
5190
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5191
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
I
Ilya Dryomov 已提交
5192
	rbd_opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
A
Alex Elder 已提交
5193

5194
	copts = ceph_parse_options(options, mon_addrs,
5195
					mon_addrs + mon_addrs_size - 1,
5196
					parse_rbd_opts_token, rbd_opts);
5197 5198
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5199 5200
		goto out_err;
	}
5201 5202 5203
	kfree(options);

	*ceph_opts = copts;
5204
	*opts = rbd_opts;
5205
	*rbd_spec = spec;
5206

5207
	return 0;
5208
out_mem:
5209
	ret = -ENOMEM;
A
Alex Elder 已提交
5210
out_err:
5211 5212
	kfree(rbd_opts);
	rbd_spec_put(spec);
5213
	kfree(options);
A
Alex Elder 已提交
5214

5215
	return ret;
5216 5217
}

I
Ilya Dryomov 已提交
5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244
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
5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262
/*
 * 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;
5263
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5264
	void *response;
5265
	char *image_id;
5266

A
Alex Elder 已提交
5267 5268 5269
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5270 5271
	 * 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
5272
	 */
5273 5274 5275
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5276
		return 0;
5277
	}
A
Alex Elder 已提交
5278

A
Alex Elder 已提交
5279 5280 5281 5282
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5283 5284 5285 5286 5287 5288
	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
5289 5290 5291 5292 5293 5294 5295 5296 5297 5298

	/* 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;
	}

5299 5300
	/* If it doesn't exist we'll assume it's a format 1 image */

5301 5302 5303
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5304
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5305 5306 5307 5308 5309
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5310
	} else if (ret >= 0) {
5311 5312 5313
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5314
						NULL, GFP_NOIO);
5315
		ret = PTR_ERR_OR_ZERO(image_id);
5316 5317 5318 5319 5320 5321 5322
		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
5323 5324 5325
	}
out:
	kfree(response);
5326
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5327 5328 5329
	return ret;
}

A
Alex Elder 已提交
5330 5331 5332 5333
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5334 5335 5336 5337
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5338
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5339 5340 5341 5342

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

	header = &rbd_dev->header;
5343
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5344 5345 5346 5347 5348 5349
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5350
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5351 5352 5353
{
	int ret;

5354
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5355
	if (ret)
5356 5357
		goto out_err;

5358 5359 5360 5361
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5362
	ret = rbd_dev_v2_features(rbd_dev);
5363
	if (ret)
5364
		goto out_err;
5365

5366 5367 5368 5369 5370 5371 5372
	/* 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;
	}
5373

5374 5375 5376 5377 5378 5379
	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
5380
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5381
	return 0;
I
Ilya Dryomov 已提交
5382

5383
out_err:
A
Alex Elder 已提交
5384
	rbd_dev->header.features = 0;
5385 5386
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5387
	return ret;
5388 5389
}

5390 5391 5392 5393 5394 5395
/*
 * @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
5396
{
5397
	struct rbd_device *parent = NULL;
5398 5399 5400 5401 5402
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5403 5404 5405 5406 5407 5408
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5409
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5410 5411
	if (!parent) {
		ret = -ENOMEM;
5412
		goto out_err;
5413 5414 5415 5416 5417 5418 5419 5420
	}

	/*
	 * 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);
5421

5422
	ret = rbd_dev_image_probe(parent, depth);
5423 5424
	if (ret < 0)
		goto out_err;
5425

5426
	rbd_dev->parent = parent;
5427
	atomic_set(&rbd_dev->parent_ref, 1);
5428
	return 0;
5429

5430
out_err:
5431
	rbd_dev_unparent(rbd_dev);
5432
	rbd_dev_destroy(parent);
5433 5434 5435
	return ret;
}

5436 5437 5438 5439 5440 5441 5442 5443 5444
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
5445 5446 5447 5448
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5449
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5450
{
A
Alex Elder 已提交
5451
	int ret;
A
Alex Elder 已提交
5452

5453
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5454

5455 5456 5457
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5458
			goto err_out_unlock;
5459 5460 5461 5462 5463 5464 5465

		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
5466 5467 5468 5469 5470 5471 5472

	/* Set up the blkdev mapping. */

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

5473
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5474 5475
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5476

5477
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5478
	set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only);
5479

5480
	ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
5481
	if (ret)
5482
		goto err_out_mapping;
A
Alex Elder 已提交
5483

5484
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5485
	up_write(&rbd_dev->header_rwsem);
5486
	return 0;
5487

5488 5489
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5490 5491 5492
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5493 5494
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
5495 5496
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5497 5498 5499
	return ret;
}

A
Alex Elder 已提交
5500 5501 5502
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
5503
	int ret;
A
Alex Elder 已提交
5504 5505 5506 5507 5508

	/* 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)
5509 5510
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
5511
	else
5512 5513
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
5514

5515
	return ret;
A
Alex Elder 已提交
5516 5517
}

5518 5519
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5520
	rbd_dev_unprobe(rbd_dev);
5521 5522
	if (rbd_dev->opts)
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5523 5524 5525
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5526 5527
}

5528 5529
/*
 * Probe for the existence of the header object for the given rbd
5530 5531 5532
 * 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.
5533
 */
5534
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
5535 5536 5537 5538
{
	int ret;

	/*
A
Alex Elder 已提交
5539 5540 5541 5542
	 * 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.
5543 5544 5545
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
5546 5547
		return ret;

A
Alex Elder 已提交
5548 5549 5550 5551
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

5552
	if (!depth) {
5553
		ret = rbd_register_watch(rbd_dev);
5554 5555 5556 5557 5558
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
5559
			goto err_out_format;
5560
		}
5561
	}
5562

5563
	ret = rbd_dev_header_info(rbd_dev);
5564
	if (ret)
5565
		goto err_out_watch;
A
Alex Elder 已提交
5566

5567 5568 5569 5570 5571 5572
	/*
	 * 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.
	 */
5573
	if (!depth)
5574 5575 5576
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
5577 5578 5579 5580 5581 5582
	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
5583
		goto err_out_probe;
5584
	}
5585

5586 5587 5588 5589 5590 5591 5592 5593 5594
	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.
		 */
5595
		if (!depth && rbd_dev->parent_spec)
5596 5597 5598 5599
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

5600
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
5601 5602 5603 5604
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
5605
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
5606
	return 0;
5607

A
Alex Elder 已提交
5608 5609
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
5610
err_out_watch:
5611
	if (!depth)
5612
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5613 5614
err_out_format:
	rbd_dev->image_format = 0;
5615 5616
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5617 5618 5619
	return ret;
}

5620 5621 5622
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
5623
{
5624
	struct rbd_device *rbd_dev = NULL;
5625
	struct ceph_options *ceph_opts = NULL;
5626
	struct rbd_options *rbd_opts = NULL;
5627
	struct rbd_spec *spec = NULL;
5628
	struct rbd_client *rbdc;
5629
	int rc;
5630 5631 5632 5633 5634

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

	/* parse add command */
5635
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
5636
	if (rc < 0)
5637
		goto out;
5638

5639 5640 5641
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
5642
		goto err_out_args;
5643
	}
5644 5645

	/* pick the pool */
5646
	rc = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, spec->pool_name);
5647 5648 5649
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
5650
		goto err_out_client;
5651
	}
A
Alex Elder 已提交
5652
	spec->pool_id = (u64)rc;
5653

5654
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
5655 5656
	if (!rbd_dev) {
		rc = -ENOMEM;
5657
		goto err_out_client;
5658
	}
5659 5660
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
5661
	rbd_opts = NULL;	/* rbd_dev now owns this */
5662

5663 5664 5665 5666 5667 5668
	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
5669
	down_write(&rbd_dev->header_rwsem);
5670
	rc = rbd_dev_image_probe(rbd_dev, 0);
5671 5672
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
5673
		goto err_out_rbd_dev;
5674
	}
5675

5676 5677
	/* If we are mapping a snapshot it must be marked read-only */
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
5678
		rbd_dev->opts->read_only = true;
5679

5680
	rc = rbd_dev_device_setup(rbd_dev);
5681
	if (rc)
5682
		goto err_out_image_probe;
A
Alex Elder 已提交
5683

I
Ilya Dryomov 已提交
5684 5685 5686 5687
	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
5688 5689
	}

5690 5691 5692 5693
	/* Everything's ready.  Announce the disk to the world. */

	rc = device_add(&rbd_dev->dev);
	if (rc)
I
Ilya Dryomov 已提交
5694
		goto err_out_image_lock;
5695 5696 5697 5698 5699 5700 5701 5702 5703 5704 5705 5706

	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);
5707 5708 5709 5710
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
5711

I
Ilya Dryomov 已提交
5712 5713
err_out_image_lock:
	rbd_dev_image_unlock(rbd_dev);
5714 5715
err_out_device_setup:
	rbd_dev_device_release(rbd_dev);
5716 5717
err_out_image_probe:
	rbd_dev_image_release(rbd_dev);
5718 5719
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
5720
err_out_client:
5721
	rbd_put_client(rbdc);
5722
err_out_args:
5723
	rbd_spec_put(spec);
5724
	kfree(rbd_opts);
5725
	goto out;
5726 5727
}

5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743 5744
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);
}

5745 5746
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5747
	while (rbd_dev->parent) {
5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759
		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
5760
		rbd_assert(second);
5761
		rbd_dev_image_release(second);
5762
		rbd_dev_destroy(second);
A
Alex Elder 已提交
5763 5764 5765 5766
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
5767 5768 5769 5770 5771
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

5772 5773 5774
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
5775 5776
{
	struct rbd_device *rbd_dev = NULL;
5777 5778
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
5779
	char opt_buf[6];
5780
	bool already = false;
M
Mike Christie 已提交
5781
	bool force = false;
5782
	int ret;
5783

M
Mike Christie 已提交
5784 5785 5786 5787 5788
	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");
5789
		return -EINVAL;
M
Mike Christie 已提交
5790 5791 5792 5793 5794 5795 5796 5797 5798
	}
	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;
		}
	}
5799

5800 5801 5802 5803 5804 5805 5806 5807
	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;
		}
5808
	}
5809 5810
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
5811
		if (rbd_dev->open_count && !force)
5812 5813
			ret = -EBUSY;
		else
5814 5815
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
5816 5817 5818
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
5819
	if (ret < 0 || already)
5820
		return ret;
5821

M
Mike Christie 已提交
5822 5823 5824 5825 5826 5827 5828 5829 5830
	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);
	}

5831 5832 5833 5834 5835
	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);
5836

I
Ilya Dryomov 已提交
5837
	rbd_dev_image_unlock(rbd_dev);
5838
	rbd_dev_device_release(rbd_dev);
5839
	rbd_dev_image_release(rbd_dev);
5840
	rbd_dev_destroy(rbd_dev);
5841
	return count;
5842 5843
}

5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860
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);
}

5861 5862
/*
 * create control files in sysfs
5863
 * /sys/bus/rbd/...
5864 5865 5866
 */
static int rbd_sysfs_init(void)
{
5867
	int ret;
5868

5869
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
5870
	if (ret < 0)
5871
		return ret;
5872

5873 5874 5875
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
5876 5877 5878 5879 5880 5881

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
5882
	bus_unregister(&rbd_bus_type);
5883
	device_unregister(&rbd_root_dev);
5884 5885
}

5886 5887 5888
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
5889
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
5890 5891 5892 5893
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
5894
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
5895 5896 5897
	if (!rbd_obj_request_cache)
		goto out_err;

5898
	return 0;
5899

5900
out_err:
5901 5902
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
5903 5904 5905 5906 5907
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
5908 5909 5910 5911
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

5912 5913 5914 5915 5916
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
5917
static int __init rbd_init(void)
5918 5919 5920
{
	int rc;

5921 5922 5923 5924
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
5925

5926
	rc = rbd_slab_init();
5927 5928
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
5929

5930 5931
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
5932
	 * rbd devices * queue depth, so leave @max_active at default.
5933 5934 5935 5936 5937 5938 5939
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

5940 5941 5942 5943
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
5944
			goto err_out_wq;
5945 5946 5947
		}
	}

5948 5949
	rc = rbd_sysfs_init();
	if (rc)
5950 5951 5952 5953 5954 5955
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
5956

I
Ilya Dryomov 已提交
5957 5958
	return 0;

5959 5960 5961
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
5962 5963
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
5964 5965
err_out_slab:
	rbd_slab_exit();
5966
	return rc;
5967 5968
}

A
Alex Elder 已提交
5969
static void __exit rbd_exit(void)
5970
{
I
Ilya Dryomov 已提交
5971
	ida_destroy(&rbd_dev_id_ida);
5972
	rbd_sysfs_cleanup();
5973 5974
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
5975
	destroy_workqueue(rbd_wq);
5976
	rbd_slab_exit();
5977 5978 5979 5980 5981
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
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MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
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MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
/* following authorship retained from original osdblk.c */
MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");

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