rbd.c 147.0 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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};
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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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		};
	};
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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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	u64			offset;	/* starting image byte offset */
	u64			length;	/* byte count from offset */
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	unsigned long		flags;
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	union {
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		u64			snap_id;	/* for reads */
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		struct ceph_snap_context *snapc;	/* for writes */
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	};
	union {
		struct request		*rq;		/* block request */
		struct rbd_obj_request	*obj_request;	/* obj req initiator */
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	};
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	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 void rbd_spec_put(struct rbd_spec *spec);
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static int rbd_dev_id_to_minor(int dev_id)
{
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	return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
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}

static int minor_to_rbd_dev_id(int minor)
{
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	return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
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}

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static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
{
	return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
	       rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
}

static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
{
	bool is_lock_owner;

	down_read(&rbd_dev->lock_rwsem);
	is_lock_owner = __rbd_is_lock_owner(rbd_dev);
	up_read(&rbd_dev->lock_rwsem);
	return is_lock_owner;
}

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static ssize_t rbd_supported_features_show(struct bus_type *bus, char *buf)
{
	return sprintf(buf, "0x%llx\n", RBD_FEATURES_SUPPORTED);
}

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static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
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static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
static BUS_ATTR(remove_single_major, S_IWUSR, NULL, rbd_remove_single_major);
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static BUS_ATTR(supported_features, S_IRUGO, rbd_supported_features_show, NULL);
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static struct attribute *rbd_bus_attrs[] = {
	&bus_attr_add.attr,
	&bus_attr_remove.attr,
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	&bus_attr_add_single_major.attr,
	&bus_attr_remove_single_major.attr,
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	&bus_attr_supported_features.attr,
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	NULL,
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};
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static umode_t rbd_bus_is_visible(struct kobject *kobj,
				  struct attribute *attr, int index)
{
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	if (!single_major &&
	    (attr == &bus_attr_add_single_major.attr ||
	     attr == &bus_attr_remove_single_major.attr))
		return 0;

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	return attr->mode;
}

static const struct attribute_group rbd_bus_group = {
	.attrs = rbd_bus_attrs,
	.is_visible = rbd_bus_is_visible,
};
__ATTRIBUTE_GROUPS(rbd_bus);
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static struct bus_type rbd_bus_type = {
	.name		= "rbd",
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	.bus_groups	= rbd_bus_groups,
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};

static void rbd_root_dev_release(struct device *dev)
{
}

static struct device rbd_root_dev = {
	.init_name =    "rbd",
	.release =      rbd_root_dev_release,
};

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static __printf(2, 3)
void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;

	if (!rbd_dev)
		printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
	else if (rbd_dev->disk)
		printk(KERN_WARNING "%s: %s: %pV\n",
			RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
	else if (rbd_dev->spec && rbd_dev->spec->image_name)
		printk(KERN_WARNING "%s: image %s: %pV\n",
			RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
	else if (rbd_dev->spec && rbd_dev->spec->image_id)
		printk(KERN_WARNING "%s: id %s: %pV\n",
			RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
	else	/* punt */
		printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
			RBD_DRV_NAME, rbd_dev, &vaf);
	va_end(args);
}

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#ifdef RBD_DEBUG
#define rbd_assert(expr)						\
		if (unlikely(!(expr))) {				\
			printk(KERN_ERR "\nAssertion failure in %s() "	\
						"at line %d:\n\n"	\
					"\trbd_assert(%s);\n\n",	\
					__func__, __LINE__, #expr);	\
			BUG();						\
		}
#else /* !RBD_DEBUG */
#  define rbd_assert(expr)	((void) 0)
#endif /* !RBD_DEBUG */
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static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
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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++;
590
	spin_unlock_irq(&rbd_dev->lock);
591 592 593
	if (removing)
		return -ENOENT;

A
Alex Elder 已提交
594
	(void) get_device(&rbd_dev->dev);
595

596 597 598
	return 0;
}

599
static void rbd_release(struct gendisk *disk, fmode_t mode)
600 601
{
	struct rbd_device *rbd_dev = disk->private_data;
602 603
	unsigned long open_count_before;

604
	spin_lock_irq(&rbd_dev->lock);
605
	open_count_before = rbd_dev->open_count--;
606
	spin_unlock_irq(&rbd_dev->lock);
607
	rbd_assert(open_count_before > 0);
608

A
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609
	put_device(&rbd_dev->dev);
610 611
}

G
Guangliang Zhao 已提交
612 613
static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
614
	int ro;
G
Guangliang Zhao 已提交
615

616
	if (get_user(ro, (int __user *)arg))
G
Guangliang Zhao 已提交
617 618
		return -EFAULT;

619
	/* Snapshots can't be marked read-write */
G
Guangliang Zhao 已提交
620 621 622
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
		return -EROFS;

623 624
	/* Let blkdev_roset() handle it */
	return -ENOTTY;
G
Guangliang Zhao 已提交
625 626 627 628 629 630
}

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;
631
	int ret;
G
Guangliang Zhao 已提交
632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651

	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 */

652 653 654
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
655
	.release		= rbd_release,
G
Guangliang Zhao 已提交
656 657 658 659
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
660 661 662
};

/*
663
 * Initialize an rbd client instance.  Success or not, this function
664
 * consumes ceph_opts.  Caller holds client_mutex.
665
 */
666
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
667 668 669 670
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

A
Alex Elder 已提交
671
	dout("%s:\n", __func__);
672 673 674 675 676 677 678
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

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

679
	rbdc->client = ceph_create_client(ceph_opts, rbdc);
680
	if (IS_ERR(rbdc->client))
681
		goto out_rbdc;
A
Alex Elder 已提交
682
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
683 684 685

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
686
		goto out_client;
687

A
Alex Elder 已提交
688
	spin_lock(&rbd_client_list_lock);
689
	list_add_tail(&rbdc->node, &rbd_client_list);
A
Alex Elder 已提交
690
	spin_unlock(&rbd_client_list_lock);
691

A
Alex Elder 已提交
692
	dout("%s: rbdc %p\n", __func__, rbdc);
693

694
	return rbdc;
695
out_client:
696
	ceph_destroy_client(rbdc->client);
697
out_rbdc:
698 699
	kfree(rbdc);
out_opt:
A
Alex Elder 已提交
700 701
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
A
Alex Elder 已提交
702 703
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
704
	return ERR_PTR(ret);
705 706
}

707 708 709 710 711 712 713
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

714
/*
715 716
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
717
 */
718
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
719 720
{
	struct rbd_client *client_node;
721
	bool found = false;
722

A
Alex Elder 已提交
723
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
724 725
		return NULL;

726 727 728
	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)) {
729 730
			__rbd_get_client(client_node);

731 732 733 734 735 736 737
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
738 739
}

740
/*
741
 * (Per device) rbd map options
742 743
 */
enum {
I
Ilya Dryomov 已提交
744
	Opt_queue_depth,
745 746 747 748
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
A
Alex Elder 已提交
749 750
	Opt_read_only,
	Opt_read_write,
I
Ilya Dryomov 已提交
751
	Opt_lock_on_read,
I
Ilya Dryomov 已提交
752
	Opt_exclusive,
753
	Opt_err
754 755
};

A
Alex Elder 已提交
756
static match_table_t rbd_opts_tokens = {
I
Ilya Dryomov 已提交
757
	{Opt_queue_depth, "queue_depth=%d"},
758 759
	/* int args above */
	/* string args above */
A
Alex Elder 已提交
760
	{Opt_read_only, "read_only"},
A
Alex Elder 已提交
761 762 763
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
I
Ilya Dryomov 已提交
764
	{Opt_lock_on_read, "lock_on_read"},
I
Ilya Dryomov 已提交
765
	{Opt_exclusive, "exclusive"},
766
	{Opt_err, NULL}
767 768
};

A
Alex Elder 已提交
769
struct rbd_options {
I
Ilya Dryomov 已提交
770
	int	queue_depth;
A
Alex Elder 已提交
771
	bool	read_only;
I
Ilya Dryomov 已提交
772
	bool	lock_on_read;
I
Ilya Dryomov 已提交
773
	bool	exclusive;
A
Alex Elder 已提交
774 775
};

I
Ilya Dryomov 已提交
776
#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
A
Alex Elder 已提交
777
#define RBD_READ_ONLY_DEFAULT	false
I
Ilya Dryomov 已提交
778
#define RBD_LOCK_ON_READ_DEFAULT false
I
Ilya Dryomov 已提交
779
#define RBD_EXCLUSIVE_DEFAULT	false
A
Alex Elder 已提交
780

781 782
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
783
	struct rbd_options *rbd_opts = private;
784 785 786
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
Alex Elder 已提交
787
	token = match_token(c, rbd_opts_tokens, argstr);
788 789 790
	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
791
			pr_err("bad mount option arg (not int) at '%s'\n", c);
792 793 794 795
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
796
		dout("got string token %d val %s\n", token, argstr[0].from);
797 798 799 800 801
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
I
Ilya Dryomov 已提交
802 803 804 805 806 807 808
	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
809 810 811 812 813 814
	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
815 816 817
	case Opt_lock_on_read:
		rbd_opts->lock_on_read = true;
		break;
I
Ilya Dryomov 已提交
818 819 820
	case Opt_exclusive:
		rbd_opts->exclusive = true;
		break;
821
	default:
822 823
		/* libceph prints "bad option" msg */
		return -EINVAL;
824
	}
825

826 827 828
	return 0;
}

G
Guangliang Zhao 已提交
829 830 831 832 833 834 835
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";
836 837
	case OBJ_OP_DISCARD:
		return "discard";
G
Guangliang Zhao 已提交
838 839 840 841 842
	default:
		return "???";
	}
}

843 844
/*
 * Get a ceph client with specific addr and configuration, if one does
845 846
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
847
 */
848
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
849
{
850
	struct rbd_client *rbdc;
851

852
	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
853
	rbdc = rbd_client_find(ceph_opts);
854
	if (rbdc)	/* using an existing client */
A
Alex Elder 已提交
855
		ceph_destroy_options(ceph_opts);
856
	else
857
		rbdc = rbd_client_create(ceph_opts);
858
	mutex_unlock(&client_mutex);
859

860
	return rbdc;
861 862 863 864
}

/*
 * Destroy ceph client
A
Alex Elder 已提交
865
 *
A
Alex Elder 已提交
866
 * Caller must hold rbd_client_list_lock.
867 868 869 870 871
 */
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
872
	dout("%s: rbdc %p\n", __func__, rbdc);
873
	spin_lock(&rbd_client_list_lock);
874
	list_del(&rbdc->node);
875
	spin_unlock(&rbd_client_list_lock);
876 877 878 879 880 881 882 883 884

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

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
885
static void rbd_put_client(struct rbd_client *rbdc)
886
{
887 888
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
889 890
}

891 892 893 894 895
static bool rbd_image_format_valid(u32 image_format)
{
	return image_format == 1 || image_format == 2;
}

896 897
static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
{
898 899 900 901 902 903 904
	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
905 906 907 908 909 910 911 912 913 914
	/* 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;

915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932
	/*
	 * 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;
933 934
}

I
Ilya Dryomov 已提交
935 936 937 938 939 940 941 942
/*
 * 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
943 944 945 946 947 948 949 950 951 952 953
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);
954 955
	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
956 957 958
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
}

959
/*
960 961
 * Fill an rbd image header with information from the given format 1
 * on-disk header.
962
 */
A
Alex Elder 已提交
963
static int rbd_header_from_disk(struct rbd_device *rbd_dev,
964
				 struct rbd_image_header_ondisk *ondisk)
965
{
A
Alex Elder 已提交
966
	struct rbd_image_header *header = &rbd_dev->header;
967 968 969 970 971
	bool first_time = header->object_prefix == NULL;
	struct ceph_snap_context *snapc;
	char *object_prefix = NULL;
	char *snap_names = NULL;
	u64 *snap_sizes = NULL;
972
	u32 snap_count;
973
	int ret = -ENOMEM;
974
	u32 i;
975

976
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
977

978
	if (first_time) {
979 980 981
		object_prefix = kstrndup(ondisk->object_prefix,
					 sizeof(ondisk->object_prefix),
					 GFP_KERNEL);
982 983 984
		if (!object_prefix)
			return -ENOMEM;
	}
A
Alex Elder 已提交
985

986
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
987

988 989 990 991 992
	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);
993
	if (snap_count) {
994
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
995 996
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

997
		/* We'll keep a copy of the snapshot names... */
998

999 1000 1001 1002
		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
1003 1004
			goto out_err;

1005
		/* ...as well as the array of their sizes. */
1006 1007 1008
		snap_sizes = kmalloc_array(snap_count,
					   sizeof(*header->snap_sizes),
					   GFP_KERNEL);
1009
		if (!snap_sizes)
A
Alex Elder 已提交
1010
			goto out_err;
1011

A
Alex Elder 已提交
1012
		/*
1013 1014 1015
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
1016
		 * Note that rbd_dev_v1_header_info() guarantees the
1017
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
1018 1019 1020
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
1021 1022 1023 1024 1025 1026
		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);
		}
1027
	}
A
Alex Elder 已提交
1028

1029
	/* We won't fail any more, fill in the header */
1030

1031 1032 1033
	if (first_time) {
		header->object_prefix = object_prefix;
		header->obj_order = ondisk->options.order;
I
Ilya Dryomov 已提交
1034
		rbd_init_layout(rbd_dev);
1035
	} else {
A
Alex Elder 已提交
1036 1037 1038
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
1039
	}
1040

1041
	/* The remaining fields always get updated (when we refresh) */
1042

A
Alex Elder 已提交
1043
	header->image_size = le64_to_cpu(ondisk->image_size);
1044 1045 1046
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1047

1048
	return 0;
1049 1050
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1051
out_err:
1052 1053 1054 1055
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1056

1057
	return ret;
1058 1059
}

1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074
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);
}

1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098
/*
 * 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.
 */
1099 1100 1101
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1102
	u64 *found;
1103

1104 1105
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1106

1107
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1108 1109
}

1110 1111
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1112
{
1113
	u32 which;
1114
	const char *snap_name;
1115

1116 1117
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1118
		return ERR_PTR(-ENOENT);
1119

1120 1121
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1122 1123 1124 1125
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1126 1127 1128
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1129 1130 1131
	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);
1132

1133
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1134 1135
}

1136 1137
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1138
{
1139 1140 1141 1142 1143
	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;
1144

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

1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
		*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;
1161 1162
}

1163 1164
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1165
{
1166 1167 1168 1169 1170
	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 */
1171
	} else {
1172 1173
		u64 features = 0;
		int ret;
1174

1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
		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)
{
1186
	u64 snap_id = rbd_dev->spec->snap_id;
1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
	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;

1201
	return 0;
1202 1203
}

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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;
1208 1209
}

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static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
I
Ilya Dryomov 已提交
1212
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
1213

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1214 1215 1216 1217 1218 1219
	return offset & (segment_size - 1);
}

static u64 rbd_segment_length(struct rbd_device *rbd_dev,
				u64 offset, u64 length)
{
I
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1220
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
A
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1221 1222 1223

	offset &= segment_size - 1;

A
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1224
	rbd_assert(length <= U64_MAX - offset);
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	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1229 1230
}

1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251
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);
	}));
}

1252 1253 1254 1255 1256 1257 1258 1259
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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1260 1261
}

I
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1262 1263 1264 1265 1266 1267 1268 1269 1270
/*
 * Zero a range in @obj_req data buffer defined by a bio (list) or
 * bio_vec array.
 *
 * @off is relative to the start of the data buffer.
 */
static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off,
			       u32 bytes)
{
1271
	switch (obj_req->img_request->data_type) {
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1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
	case OBJ_REQUEST_BIO:
		zero_bios(&obj_req->bio_pos, off, bytes);
		break;
	case OBJ_REQUEST_BVECS:
		zero_bvecs(&obj_req->bvec_pos, off, bytes);
		break;
	default:
		rbd_assert(0);
	}
}

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1283 1284
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
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1285
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
1286
		kref_read(&obj_request->kref));
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	kref_get(&obj_request->kref);
}

static void rbd_obj_request_destroy(struct kref *kref);
static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
{
	rbd_assert(obj_request != NULL);
A
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1294
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
1295
		kref_read(&obj_request->kref));
A
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1296 1297 1298
	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1299 1300 1301
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
1302
	     kref_read(&img_request->kref));
1303 1304 1305
	kref_get(&img_request->kref);
}

1306 1307
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
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static void rbd_img_request_destroy(struct kref *kref);
static void rbd_img_request_put(struct rbd_img_request *img_request)
{
	rbd_assert(img_request != NULL);
A
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1312
	dout("%s: img %p (was %d)\n", __func__, img_request,
1313
		kref_read(&img_request->kref));
1314 1315 1316 1317
	if (img_request_child_test(img_request))
		kref_put(&img_request->kref, rbd_parent_request_destroy);
	else
		kref_put(&img_request->kref, rbd_img_request_destroy);
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1318 1319 1320 1321 1322
}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1323 1324
	rbd_assert(obj_request->img_request == NULL);

1325
	/* Image request now owns object's original reference */
A
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1326
	obj_request->img_request = img_request;
1327
	img_request->obj_request_count++;
I
Ilya Dryomov 已提交
1328
	img_request->pending_count++;
1329
	list_add_tail(&obj_request->ex.oe_item, &img_request->object_extents);
1330
	dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
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1331 1332 1333 1334 1335
}

static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1336
	dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1337
	list_del(&obj_request->ex.oe_item);
1338 1339
	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);
}

1344
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1345
{
1346 1347
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1348
	dout("%s %p object_no %016llx %llu~%llu osd_req %p\n", __func__,
1349 1350
	     obj_request, obj_request->ex.oe_objno, obj_request->ex.oe_off,
	     obj_request->ex.oe_len, osd_req);
1351
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
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1352 1353
}

A
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/*
 * 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.
 */
1359 1360 1361 1362 1363 1364
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1365 1366 1367 1368 1369 1370
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1371 1372 1373 1374 1375 1376
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1377 1378 1379 1380 1381 1382
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1383 1384 1385 1386 1387 1388
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1389 1390 1391 1392 1393 1394
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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1395 1396 1397 1398
static bool rbd_obj_is_entire(struct rbd_obj_request *obj_req)
{
	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;

1399 1400
	return !obj_req->ex.oe_off &&
	       obj_req->ex.oe_len == rbd_dev->layout.object_size;
I
Ilya Dryomov 已提交
1401 1402 1403 1404 1405 1406
}

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

1407
	return obj_req->ex.oe_off + obj_req->ex.oe_len ==
I
Ilya Dryomov 已提交
1408 1409 1410
					rbd_dev->layout.object_size;
}

I
Ilya Dryomov 已提交
1411 1412 1413 1414 1415 1416
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
1417 1418
static bool rbd_img_is_write(struct rbd_img_request *img_req)
{
I
Ilya Dryomov 已提交
1419
	switch (img_req->op_type) {
I
Ilya Dryomov 已提交
1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431
	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);

1432
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
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1433
{
I
Ilya Dryomov 已提交
1434
	struct rbd_obj_request *obj_req = osd_req->r_priv;
A
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1435

I
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1436 1437 1438
	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);
1439

I
Ilya Dryomov 已提交
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449
	obj_req->result = osd_req->r_result < 0 ? osd_req->r_result : 0;
	if (!obj_req->result && !rbd_img_is_write(obj_req->img_request))
		obj_req->xferred = osd_req->r_result;
	else
		/*
		 * Writes aren't allowed to return a data payload.  In some
		 * guarded write cases (e.g. stat + zero on an empty object)
		 * a stat response makes it through, but we don't care.
		 */
		obj_req->xferred = 0;
A
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1450

I
Ilya Dryomov 已提交
1451
	rbd_obj_handle_request(obj_req);
A
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1452 1453
}

1454
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
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1455
{
1456
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1457

1458
	osd_req->r_flags = CEPH_OSD_FLAG_READ;
1459
	osd_req->r_snapid = obj_request->img_request->snap_id;
1460 1461 1462 1463 1464 1465
}

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

1466
	osd_req->r_flags = CEPH_OSD_FLAG_WRITE;
1467
	ktime_get_real_ts(&osd_req->r_mtime);
1468
	osd_req->r_data_offset = obj_request->ex.oe_off;
A
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1469 1470
}

1471
static struct ceph_osd_request *
1472
rbd_osd_req_create(struct rbd_obj_request *obj_req, unsigned int num_ops)
1473
{
1474 1475
	struct rbd_img_request *img_req = obj_req->img_request;
	struct rbd_device *rbd_dev = img_req->rbd_dev;
1476 1477
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_osd_request *req;
1478 1479
	const char *name_format = rbd_dev->image_format == 1 ?
				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
1480

1481 1482 1483
	req = ceph_osdc_alloc_request(osdc,
			(rbd_img_is_write(img_req) ? img_req->snapc : NULL),
			num_ops, false, GFP_NOIO);
1484 1485 1486 1487
	if (!req)
		return NULL;

	req->r_callback = rbd_osd_req_callback;
1488
	req->r_priv = obj_req;
1489 1490

	req->r_base_oloc.pool = rbd_dev->layout.pool_id;
1491
	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
1492
			rbd_dev->header.object_prefix, obj_req->ex.oe_objno))
1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504
		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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1505 1506 1507 1508 1509
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

1510
static struct rbd_obj_request *rbd_obj_request_create(void)
A
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1511 1512 1513
{
	struct rbd_obj_request *obj_request;

1514
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
1515
	if (!obj_request)
1516 1517
		return NULL;

1518
	ceph_object_extent_init(&obj_request->ex);
A
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1519 1520
	kref_init(&obj_request->kref);

1521
	dout("%s %p\n", __func__, obj_request);
A
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1522 1523 1524 1525 1526 1527
	return obj_request;
}

static void rbd_obj_request_destroy(struct kref *kref)
{
	struct rbd_obj_request *obj_request;
1528
	u32 i;
A
Alex Elder 已提交
1529 1530 1531

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

A
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1532 1533
	dout("%s: obj %p\n", __func__, obj_request);

A
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1534 1535 1536
	if (obj_request->osd_req)
		rbd_osd_req_destroy(obj_request->osd_req);

1537
	switch (obj_request->img_request->data_type) {
1538
	case OBJ_REQUEST_NODATA:
A
Alex Elder 已提交
1539
	case OBJ_REQUEST_BIO:
1540
	case OBJ_REQUEST_BVECS:
1541
		break;		/* Nothing to do */
1542 1543
	default:
		rbd_assert(0);
A
Alex Elder 已提交
1544 1545
	}

I
Ilya Dryomov 已提交
1546
	kfree(obj_request->img_extents);
1547 1548 1549 1550 1551 1552 1553
	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);
	}
1554

1555
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
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1556 1557
}

A
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1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568
/* 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;
}

1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590
/*
 * 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
1591
		rbd_warn(rbd_dev, "parent reference underflow");
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603
}

/*
 * 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)
{
1604
	int counter = 0;
1605 1606 1607 1608

	if (!rbd_dev->parent_spec)
		return false;

1609 1610 1611 1612
	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);
1613 1614

	if (counter < 0)
1615
		rbd_warn(rbd_dev, "parent reference overflow");
1616

1617
	return counter > 0;
1618 1619
}

A
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1620 1621 1622 1623 1624
/*
 * Caller is responsible for filling in the list of object requests
 * that comprises the image request, and the Linux request pointer
 * (if there is one).
 */
A
Alex Elder 已提交
1625 1626
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
1627
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
1628
					enum obj_operation_type op_type,
1629
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
1630 1631 1632
{
	struct rbd_img_request *img_request;

1633
	img_request = kmem_cache_zalloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
1634 1635 1636 1637
	if (!img_request)
		return NULL;

	img_request->rbd_dev = rbd_dev;
I
Ilya Dryomov 已提交
1638
	img_request->op_type = op_type;
A
Alex Elder 已提交
1639 1640
	img_request->offset = offset;
	img_request->length = length;
I
Ilya Dryomov 已提交
1641
	if (!rbd_img_is_write(img_request))
A
Alex Elder 已提交
1642
		img_request->snap_id = rbd_dev->spec->snap_id;
I
Ilya Dryomov 已提交
1643 1644 1645
	else
		img_request->snapc = snapc;

1646
	if (rbd_dev_parent_get(rbd_dev))
1647
		img_request_layered_set(img_request);
1648

A
Alex Elder 已提交
1649
	spin_lock_init(&img_request->completion_lock);
1650
	INIT_LIST_HEAD(&img_request->object_extents);
A
Alex Elder 已提交
1651 1652
	kref_init(&img_request->kref);

A
Alex Elder 已提交
1653
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
1654
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
1655

A
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1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
	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
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1667 1668
	dout("%s: img %p\n", __func__, img_request);

A
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1669 1670
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
1671
	rbd_assert(img_request->obj_request_count == 0);
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1673 1674 1675 1676 1677
	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
1678
	if (rbd_img_is_write(img_request))
1679
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
1680

1681
	kmem_cache_free(rbd_img_request_cache, img_request);
A
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1682 1683
}

1684 1685 1686 1687 1688 1689 1690 1691 1692 1693
static struct rbd_img_request *rbd_parent_request_create(
					struct rbd_obj_request *obj_request,
					u64 img_offset, u64 length)
{
	struct rbd_img_request *parent_request;
	struct rbd_device *rbd_dev;

	rbd_assert(obj_request->img_request);
	rbd_dev = obj_request->img_request->rbd_dev;

1694
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
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Guangliang Zhao 已提交
1695
						length, OBJ_OP_READ, NULL);
1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720
	if (!parent_request)
		return NULL;

	img_request_child_set(parent_request);
	rbd_obj_request_get(obj_request);
	parent_request->obj_request = obj_request;

	return parent_request;
}

static void rbd_parent_request_destroy(struct kref *kref)
{
	struct rbd_img_request *parent_request;
	struct rbd_obj_request *orig_request;

	parent_request = container_of(kref, struct rbd_img_request, kref);
	orig_request = parent_request->obj_request;

	parent_request->obj_request = NULL;
	rbd_obj_request_put(orig_request);
	img_request_child_clear(parent_request);

	rbd_img_request_destroy(kref);
}

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Ilya Dryomov 已提交
1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767
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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Ilya Dryomov 已提交
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static void rbd_osd_req_setup_data(struct rbd_obj_request *obj_req, u32 which)
{
1770
	switch (obj_req->img_request->data_type) {
I
Ilya Dryomov 已提交
1771 1772 1773
	case OBJ_REQUEST_BIO:
		osd_req_op_extent_osd_data_bio(obj_req->osd_req, which,
					       &obj_req->bio_pos,
1774
					       obj_req->ex.oe_len);
I
Ilya Dryomov 已提交
1775 1776 1777
		break;
	case OBJ_REQUEST_BVECS:
		rbd_assert(obj_req->bvec_pos.iter.bi_size ==
1778
							obj_req->ex.oe_len);
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Ilya Dryomov 已提交
1779 1780 1781 1782 1783 1784 1785 1786 1787 1788
		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)
{
1789
	obj_req->osd_req = rbd_osd_req_create(obj_req, 1);
I
Ilya Dryomov 已提交
1790 1791 1792 1793
	if (!obj_req->osd_req)
		return -ENOMEM;

	osd_req_op_extent_init(obj_req->osd_req, 0, CEPH_OSD_OP_READ,
1794
			       obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
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Ilya Dryomov 已提交
1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840
	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,
1841
			       obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
I
Ilya Dryomov 已提交
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852
	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;

I
Ilya Dryomov 已提交
1853 1854 1855 1856 1857 1858
	/* 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) {
I
Ilya Dryomov 已提交
1859 1860 1861 1862 1863 1864 1865
		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 */
	}

1866
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
I
Ilya Dryomov 已提交
1867 1868 1869
	if (!obj_req->osd_req)
		return -ENOMEM;

I
Ilya Dryomov 已提交
1870
	if (obj_req->num_img_extents) {
I
Ilya Dryomov 已提交
1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
		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)) {
I
Ilya Dryomov 已提交
1886
		if (obj_req->num_img_extents) {
I
Ilya Dryomov 已提交
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900
			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,
1901
				       obj_req->ex.oe_off, obj_req->ex.oe_len,
I
Ilya Dryomov 已提交
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
				       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;

I
Ilya Dryomov 已提交
1913 1914 1915 1916 1917
	/* reverse map the entire object onto the parent */
	ret = rbd_obj_calc_img_extents(obj_req, true);
	if (ret)
		return ret;

I
Ilya Dryomov 已提交
1918 1919 1920 1921
	if (rbd_obj_is_entire(obj_req)) {
		obj_req->write_state = RBD_OBJ_WRITE_FLAT;
		num_osd_ops = 1; /* truncate/delete */
	} else {
I
Ilya Dryomov 已提交
1922
		if (obj_req->num_img_extents) {
I
Ilya Dryomov 已提交
1923 1924 1925 1926 1927 1928 1929 1930
			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 */
		}
	}

1931
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
I
Ilya Dryomov 已提交
1932 1933 1934
	if (!obj_req->osd_req)
		return -ENOMEM;

I
Ilya Dryomov 已提交
1935
	if (!rbd_obj_is_entire(obj_req) && obj_req->num_img_extents) {
I
Ilya Dryomov 已提交
1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
		ret = __rbd_obj_setup_stat(obj_req, which++);
		if (ret)
			return ret;
	}

	__rbd_obj_setup_discard(obj_req, which);
	return 0;
}

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

	for_each_obj_request(img_req, obj_req) {
I
Ilya Dryomov 已提交
1956
		switch (img_req->op_type) {
I
Ilya Dryomov 已提交
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
		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;
}

1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986
/*
 * Split up an image request into one or more object requests, each
 * to a different object.  The "type" parameter indicates whether
 * "data_desc" is the pointer to the head of a list of bio
 * structures, or the base of a page array.  In either case this
 * function assumes data_desc describes memory sufficient to hold
 * all data described by the image request.
 */
static int rbd_img_request_fill(struct rbd_img_request *img_request,
					enum obj_request_type type,
					void *data_desc)
A
Alex Elder 已提交
1987 1988 1989 1990
{
	struct rbd_device *rbd_dev = img_request->rbd_dev;
	struct rbd_obj_request *obj_request = NULL;
	struct rbd_obj_request *next_obj_request;
1991
	struct ceph_bio_iter bio_it;
1992
	struct ceph_bvec_iter bvec_it;
1993
	u64 img_offset;
A
Alex Elder 已提交
1994 1995
	u64 resid;

1996 1997
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
1998

1999
	img_offset = img_request->offset;
A
Alex Elder 已提交
2000
	resid = img_request->length;
A
Alex Elder 已提交
2001
	rbd_assert(resid > 0);
2002 2003

	if (type == OBJ_REQUEST_BIO) {
2004
		bio_it = *(struct ceph_bio_iter *)data_desc;
2005
		rbd_assert(img_offset ==
2006
			   bio_it.iter.bi_sector << SECTOR_SHIFT);
2007 2008
	} else if (type == OBJ_REQUEST_BVECS) {
		bvec_it = *(struct ceph_bvec_iter *)data_desc;
2009 2010
	}

A
Alex Elder 已提交
2011
	while (resid) {
2012
		u64 object_no = img_offset >> rbd_dev->header.obj_order;
2013 2014
		u64 offset = rbd_segment_offset(rbd_dev, img_offset);
		u64 length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2015

2016
		obj_request = rbd_obj_request_create();
A
Alex Elder 已提交
2017 2018
		if (!obj_request)
			goto out_unwind;
2019

2020 2021 2022
		obj_request->ex.oe_objno = object_no;
		obj_request->ex.oe_off = offset;
		obj_request->ex.oe_len = length;
2023

2024 2025 2026 2027 2028
		/*
		 * set obj_request->img_request before creating the
		 * osd_request so that it gets the right snapc
		 */
		rbd_img_obj_request_add(img_request, obj_request);
A
Alex Elder 已提交
2029

2030
		if (type == OBJ_REQUEST_BIO) {
2031 2032
			obj_request->bio_pos = bio_it;
			ceph_bio_iter_advance(&bio_it, length);
2033 2034 2035 2036
		} else if (type == OBJ_REQUEST_BVECS) {
			obj_request->bvec_pos = bvec_it;
			ceph_bvec_iter_shorten(&obj_request->bvec_pos, length);
			ceph_bvec_iter_advance(&bvec_it, length);
2037
		}
A
Alex Elder 已提交
2038

2039
		img_offset += length;
A
Alex Elder 已提交
2040 2041 2042
		resid -= length;
	}

2043
	img_request->data_type = type;
I
Ilya Dryomov 已提交
2044
	return __rbd_img_fill_request(img_request);
A
Alex Elder 已提交
2045 2046 2047

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2048
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2049 2050 2051 2052

	return -ENOMEM;
}

2053
static void rbd_img_request_submit(struct rbd_img_request *img_request)
A
Alex Elder 已提交
2054 2055 2056
{
	struct rbd_obj_request *obj_request;

A
Alex Elder 已提交
2057
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
2058

2059
	rbd_img_request_get(img_request);
2060
	for_each_obj_request(img_request, obj_request)
I
Ilya Dryomov 已提交
2061
		rbd_obj_request_submit(obj_request);
A
Alex Elder 已提交
2062

2063
	rbd_img_request_put(img_request);
A
Alex Elder 已提交
2064
}
A
Alex Elder 已提交
2065

I
Ilya Dryomov 已提交
2066
static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
I
Ilya Dryomov 已提交
2067 2068 2069 2070 2071
{
	struct rbd_img_request *img_req = obj_req->img_request;
	struct rbd_img_request *child_img_req;
	int ret;

I
Ilya Dryomov 已提交
2072 2073 2074
	child_img_req = rbd_parent_request_create(obj_req,
					obj_req->img_extents[0].fe_off,
					obj_req->img_extents[0].fe_len);
I
Ilya Dryomov 已提交
2075 2076 2077 2078
	if (!child_img_req)
		return -ENOMEM;

	if (!rbd_img_is_write(img_req)) {
2079
		switch (img_req->data_type) {
I
Ilya Dryomov 已提交
2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095
		case OBJ_REQUEST_BIO:
			ret = rbd_img_request_fill(child_img_req,
						   OBJ_REQUEST_BIO,
						   &obj_req->bio_pos);
			break;
		case OBJ_REQUEST_BVECS:
			ret = rbd_img_request_fill(child_img_req,
						   OBJ_REQUEST_BVECS,
						   &obj_req->bvec_pos);
			break;
		default:
			rbd_assert(0);
		}
	} else {
		struct ceph_bvec_iter it = {
			.bvecs = obj_req->copyup_bvecs,
I
Ilya Dryomov 已提交
2096
			.iter = { .bi_size = obj_req->img_extents[0].fe_len },
I
Ilya Dryomov 已提交
2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116
		};

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

	rbd_img_request_submit(child_img_req);
	return 0;
}

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

	if (obj_req->result == -ENOENT &&
I
Ilya Dryomov 已提交
2117 2118 2119
	    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
2120 2121 2122 2123
		if (ret) {
			obj_req->result = ret;
			return true;
		}
I
Ilya Dryomov 已提交
2124 2125 2126 2127 2128 2129 2130 2131 2132 2133

		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
2134 2135 2136 2137 2138 2139 2140 2141 2142
	}

	/*
	 * -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 ||
2143
	    (!obj_req->result && obj_req->xferred < obj_req->ex.oe_len)) {
I
Ilya Dryomov 已提交
2144 2145
		rbd_assert(!obj_req->xferred || !obj_req->result);
		rbd_obj_zero_range(obj_req, obj_req->xferred,
2146
				   obj_req->ex.oe_len - obj_req->xferred);
I
Ilya Dryomov 已提交
2147
		obj_req->result = 0;
2148
		obj_req->xferred = obj_req->ex.oe_len;
I
Ilya Dryomov 已提交
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184
	}

	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).
	 */
2185
	obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops);
I
Ilya Dryomov 已提交
2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203
	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
2204
	switch (obj_req->img_request->op_type) {
I
Ilya Dryomov 已提交
2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219
	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;
}

2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247
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
2248 2249 2250 2251 2252
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
2253 2254 2255 2256
	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
2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269
		/*
		 * 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
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2270
	ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));
I
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2271 2272 2273 2274
	if (ret)
		return ret;

	obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
I
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2275
	return rbd_obj_read_from_parent(obj_req);
I
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2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305
}

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.
			 */
2306
			obj_req->xferred = obj_req->ex.oe_len;
I
Ilya Dryomov 已提交
2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329
		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
2330
	switch (obj_req->img_request->op_type) {
I
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2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342
	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;
2343
				obj_req->xferred = obj_req->ex.oe_len;
I
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2344 2345 2346 2347 2348 2349 2350 2351 2352
			}
			return true;
		}
		return false;
	default:
		rbd_assert(0);
	}
}

I
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2353 2354 2355 2356 2357
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 &&
2358
		    obj_req->xferred == obj_req->ex.oe_len) ||
I
Ilya Dryomov 已提交
2359 2360 2361 2362 2363 2364 2365 2366
		   (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",
2367 2368
		 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
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2369 2370 2371 2372 2373 2374 2375
		 obj_req->xferred);
	if (!img_req->result) {
		img_req->result = obj_req->result;
		img_req->xferred = 0;
	}
}

I
Ilya Dryomov 已提交
2376 2377 2378 2379 2380
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
2381 2382 2383
	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
2384 2385 2386 2387

	obj_req->result = img_req->result;
	obj_req->xferred = img_req->xferred;
	rbd_img_request_put(img_req);
I
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2388
}
I
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2389

I
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2390 2391 2392 2393 2394 2395 2396 2397 2398 2399
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
2400 2401 2402 2403
}

static void rbd_obj_handle_request(struct rbd_obj_request *obj_req)
{
I
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2404 2405 2406
	struct rbd_img_request *img_req;

again:
I
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2407 2408 2409
	if (!__rbd_obj_handle_request(obj_req))
		return;

I
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2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425
	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
2426 2427
}

2428
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
2429

2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465
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);
}

2466 2467 2468 2469 2470 2471 2472 2473 2474
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);
}

2475 2476 2477 2478
/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
2479
{
2480
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2481
	char cookie[32];
2482
	int ret;
A
Alex Elder 已提交
2483

I
Ilya Dryomov 已提交
2484 2485
	WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] != '\0');
2486

2487 2488 2489 2490
	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);
2491
	if (ret)
2492
		return ret;
A
Alex Elder 已提交
2493

2494
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
2495
	__rbd_lock(rbd_dev, cookie);
2496
	return 0;
A
Alex Elder 已提交
2497 2498
}

2499 2500 2501
/*
 * lock_rwsem must be held for write
 */
I
Ilya Dryomov 已提交
2502
static void rbd_unlock(struct rbd_device *rbd_dev)
2503
{
2504
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2505 2506
	int ret;

I
Ilya Dryomov 已提交
2507 2508
	WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] == '\0');
2509

2510
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
I
Ilya Dryomov 已提交
2511
			      RBD_LOCK_NAME, rbd_dev->lock_cookie);
I
Ilya Dryomov 已提交
2512 2513
	if (ret && ret != -ENOENT)
		rbd_warn(rbd_dev, "failed to unlock: %d", ret);
2514

I
Ilya Dryomov 已提交
2515 2516
	/* treat errors as the image is unlocked */
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
I
Ilya Dryomov 已提交
2517
	rbd_dev->lock_cookie[0] = '\0';
2518 2519
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
2520 2521
}

2522 2523 2524 2525
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)
2526 2527
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2528 2529 2530 2531
	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;
2532

2533
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
2534

2535 2536 2537 2538 2539
	/* 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);
2540

2541 2542 2543
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
2544 2545
}

2546 2547
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
2548
{
2549 2550
	struct page **reply_pages;
	size_t reply_len;
2551

2552 2553 2554
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
2555

2556 2557 2558 2559
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
2560

2561
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
2562 2563
}

2564
static void rbd_notify_released_lock(struct work_struct *work)
2565
{
2566 2567
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
2568

2569
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
2570 2571
}

2572
static int rbd_request_lock(struct rbd_device *rbd_dev)
2573
{
2574 2575 2576
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
2577 2578
	int ret;

2579
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
2580

2581 2582 2583 2584
	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);
2585
		goto out;
2586
	}
2587

2588 2589 2590 2591
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
2592

2593 2594 2595 2596
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
2597

2598 2599
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
2600

2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 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
			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;
2833
	int ret = 0;
2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848

	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
2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860
	} 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);
		}
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
	} 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);
2889
	/*
2890
	 * Ensure that all in-flight IO is flushed.
2891
	 *
2892 2893
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
2894
	 */
2895 2896 2897 2898 2899 2900 2901 2902 2903
	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
2904 2905 2906 2907 2908 2909 2910 2911 2912
	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);
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 2990 2991 2992
	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);
}

2993 2994 2995 2996 2997 2998
/*
 * 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)
2999 3000 3001
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
3002
	int result = 1;
3003 3004 3005 3006 3007 3008 3009 3010 3011

	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))
3012
		return result;
3013 3014

	down_read(&rbd_dev->lock_rwsem);
3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026
	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
3027 3028 3029 3030 3031 3032 3033 3034 3035
			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;
			}
3036 3037
		}
	}
3038 3039

out_unlock:
3040
	up_read(&rbd_dev->lock_rwsem);
3041
	return result;
3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061
}

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
3062

3063 3064
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3065
				   buf, buf_size);
3066
	if (ret)
3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089
		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;
3090
	u8 struct_v = 0;
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
	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:
3124 3125
		ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
		if (ret <= 0)
3126
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
3127
						      cookie, ret);
3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145
		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
3146 3147
}

3148 3149
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3150
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3151
{
3152
	struct rbd_device *rbd_dev = arg;
3153

3154
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3155

3156 3157 3158 3159
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3160 3161 3162 3163
	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;
3164

3165
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3166
	}
3167
	mutex_unlock(&rbd_dev->watch_mutex);
3168 3169
}

3170
/*
3171
 * watch_mutex must be locked
3172
 */
3173
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3174 3175
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3176
	struct ceph_osd_linger_request *handle;
3177

3178
	rbd_assert(!rbd_dev->watch_handle);
3179
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3180

3181 3182 3183 3184 3185
	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);
3186

3187
	rbd_dev->watch_handle = handle;
3188 3189 3190
	return 0;
}

3191 3192 3193 3194
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3195
{
3196 3197
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3198

3199 3200
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3201

3202 3203 3204
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3205

3206
	rbd_dev->watch_handle = NULL;
3207 3208
}

3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227
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)
3228
{
3229 3230 3231
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3232 3233 3234 3235
	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);
3236 3237 3238 3239
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3240
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3241 3242 3243 3244 3245 3246 3247
	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
3248 3249

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
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
/*
 * 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 {
3281
		__rbd_lock(rbd_dev, cookie);
3282 3283 3284
	}
}

3285 3286 3287 3288 3289 3290 3291 3292 3293
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);
3294 3295
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
3296
		return;
3297
	}
3298 3299 3300 3301

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3302
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3303
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
3304
			wake_requests(rbd_dev, true);
3305
		} else {
3306 3307 3308
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3309 3310
		}
		mutex_unlock(&rbd_dev->watch_mutex);
3311
		return;
3312 3313 3314 3315 3316 3317
	}

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

3318 3319 3320 3321 3322
	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);

3323 3324 3325 3326 3327
	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
}

3328
/*
3329 3330
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3331 3332
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3333 3334
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3335
			     const char *method_name,
3336
			     const void *outbound,
3337
			     size_t outbound_size,
3338
			     void *inbound,
3339
			     size_t inbound_size)
3340
{
3341 3342 3343
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3344 3345 3346
	int ret;

	/*
3347 3348 3349 3350 3351
	 * 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.
3352
	 */
3353 3354 3355
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3356

3357 3358 3359
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3360

3361
		memcpy(page_address(req_page), outbound, outbound_size);
3362
	}
3363

3364 3365 3366 3367 3368 3369
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3370

3371 3372 3373 3374 3375 3376 3377
	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;
	}
3378

3379 3380 3381
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
3382 3383 3384
	return ret;
}

3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403
/*
 * 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);
3404 3405 3406
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

3407 3408 3409
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
3410
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
3411
{
C
Christoph Hellwig 已提交
3412 3413
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
3414
	struct rbd_img_request *img_request;
3415
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
3416 3417
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
3418
	enum obj_operation_type op_type;
3419
	u64 mapping_size;
I
Ilya Dryomov 已提交
3420
	bool must_be_locked;
A
Alex Elder 已提交
3421 3422
	int result;

3423 3424
	switch (req_op(rq)) {
	case REQ_OP_DISCARD:
3425
	case REQ_OP_WRITE_ZEROES:
3426
		op_type = OBJ_OP_DISCARD;
3427 3428
		break;
	case REQ_OP_WRITE:
G
Guangliang Zhao 已提交
3429
		op_type = OBJ_OP_WRITE;
3430 3431
		break;
	case REQ_OP_READ:
G
Guangliang Zhao 已提交
3432
		op_type = OBJ_OP_READ;
3433 3434 3435 3436 3437 3438
		break;
	default:
		dout("%s: non-fs request type %d\n", __func__, req_op(rq));
		result = -EIO;
		goto err;
	}
G
Guangliang Zhao 已提交
3439

I
Ilya Dryomov 已提交
3440
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
3441

I
Ilya Dryomov 已提交
3442 3443 3444 3445 3446
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
3447

3448 3449
	rbd_assert(op_type == OBJ_OP_READ ||
		   rbd_dev->spec->snap_id == CEPH_NOSNAP);
A
Alex Elder 已提交
3450

I
Ilya Dryomov 已提交
3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462
	/*
	 * 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
3463

I
Ilya Dryomov 已提交
3464 3465 3466 3467 3468 3469
	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
3470

C
Christoph Hellwig 已提交
3471 3472
	blk_mq_start_request(rq);

3473 3474
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
3475
	if (op_type != OBJ_OP_READ) {
3476 3477 3478 3479 3480 3481
		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
3482
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
3483
			 length, mapping_size);
I
Ilya Dryomov 已提交
3484 3485 3486
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
3487

I
Ilya Dryomov 已提交
3488 3489 3490
	must_be_locked =
	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
3491 3492
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
3493
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
I
Ilya Dryomov 已提交
3494 3495 3496 3497 3498 3499
		    !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;
			}
3500
			rbd_wait_state_locked(rbd_dev);
I
Ilya Dryomov 已提交
3501
		}
3502 3503 3504 3505
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
3506 3507
	}

G
Guangliang Zhao 已提交
3508
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
3509
					     snapc);
I
Ilya Dryomov 已提交
3510 3511
	if (!img_request) {
		result = -ENOMEM;
3512
		goto err_unlock;
I
Ilya Dryomov 已提交
3513 3514
	}
	img_request->rq = rq;
3515
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
3516

3517 3518 3519
	if (op_type == OBJ_OP_DISCARD)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
					      NULL);
3520 3521 3522 3523
	else {
		struct ceph_bio_iter bio_it = { .bio = rq->bio,
						.iter = rq->bio->bi_iter };

3524
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3525 3526
					      &bio_it);
	}
I
Ilya Dryomov 已提交
3527 3528
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3529

3530
	rbd_img_request_submit(img_request);
3531 3532
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3533
	return;
A
Alex Elder 已提交
3534

I
Ilya Dryomov 已提交
3535 3536
err_img_request:
	rbd_img_request_put(img_request);
3537 3538 3539
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
3540 3541 3542
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
3543
			 obj_op_name(op_type), length, offset, result);
3544
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
3545
err:
3546
	blk_mq_end_request(rq, errno_to_blk_status(result));
I
Ilya Dryomov 已提交
3547
}
A
Alex Elder 已提交
3548

3549
static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
C
Christoph Hellwig 已提交
3550
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
3551
{
C
Christoph Hellwig 已提交
3552 3553
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
3554

C
Christoph Hellwig 已提交
3555
	queue_work(rbd_wq, work);
3556
	return BLK_STS_OK;
A
Alex Elder 已提交
3557 3558
}

3559 3560
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
3561 3562 3563
	blk_cleanup_queue(rbd_dev->disk->queue);
	blk_mq_free_tag_set(&rbd_dev->tag_set);
	put_disk(rbd_dev->disk);
3564
	rbd_dev->disk = NULL;
3565 3566
}

3567
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
3568 3569 3570
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
3571 3572

{
3573 3574 3575 3576
	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);
3577 3578
	int ret;

3579 3580 3581
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
3582

3583 3584 3585
	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
3586

3587
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
3588
	if (ret)
3589
		goto out_req;
3590

3591 3592 3593 3594 3595
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
3596

3597 3598 3599 3600 3601 3602 3603 3604
	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);
3605

3606 3607
out_req:
	ceph_osdc_put_request(req);
3608 3609 3610
	return ret;
}

3611
/*
A
Alex Elder 已提交
3612 3613 3614
 * 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.
3615
 */
3616
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3617
{
3618
	struct rbd_image_header_ondisk *ondisk = NULL;
3619
	u32 snap_count = 0;
3620 3621 3622
	u64 names_size = 0;
	u32 want_count;
	int ret;
3623

A
Alex Elder 已提交
3624
	/*
3625 3626 3627 3628 3629
	 * 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
3630
	 */
3631 3632 3633 3634 3635 3636 3637 3638 3639 3640
	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
3641
			return -ENOMEM;
3642

3643 3644
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
3645
		if (ret < 0)
A
Alex Elder 已提交
3646
			goto out;
A
Alex Elder 已提交
3647
		if ((size_t)ret < size) {
3648
			ret = -ENXIO;
A
Alex Elder 已提交
3649 3650
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
3651
			goto out;
3652 3653 3654
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
3655
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
3656
			goto out;
3657
		}
3658

3659 3660 3661 3662
		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
3663

A
Alex Elder 已提交
3664 3665
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
3666 3667 3668
	kfree(ondisk);

	return ret;
3669 3670
}

3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689
/*
 * 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);
}

3690 3691 3692 3693 3694
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
3695 3696 3697
	 * 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.
3698
	 */
I
Ilya Dryomov 已提交
3699 3700
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
3701 3702 3703 3704 3705 3706 3707
		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
3708
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3709
{
3710
	u64 mapping_size;
A
Alex Elder 已提交
3711 3712
	int ret;

3713
	down_write(&rbd_dev->header_rwsem);
3714
	mapping_size = rbd_dev->mapping.size;
3715 3716

	ret = rbd_dev_header_info(rbd_dev);
3717
	if (ret)
3718
		goto out;
3719

3720 3721 3722 3723 3724 3725 3726
	/*
	 * 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)
3727
			goto out;
3728 3729
	}

3730
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
3731
		rbd_dev->mapping.size = rbd_dev->header.image_size;
3732 3733 3734 3735
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
3736

3737
out:
3738
	up_write(&rbd_dev->header_rwsem);
3739
	if (!ret && mapping_size != rbd_dev->mapping.size)
3740
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
3741

3742
	return ret;
A
Alex Elder 已提交
3743 3744
}

3745 3746
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
3747 3748 3749 3750 3751 3752 3753
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

3754
static const struct blk_mq_ops rbd_mq_ops = {
C
Christoph Hellwig 已提交
3755 3756 3757 3758
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

3759 3760 3761 3762
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
3763
	u64 segment_size;
C
Christoph Hellwig 已提交
3764
	int err;
3765 3766

	/* create gendisk info */
3767 3768 3769
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
3770
	if (!disk)
A
Alex Elder 已提交
3771
		return -ENOMEM;
3772

A
Alex Elder 已提交
3773
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
3774
		 rbd_dev->dev_id);
3775
	disk->major = rbd_dev->major;
3776
	disk->first_minor = rbd_dev->minor;
3777 3778
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
3779 3780 3781
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
3782 3783
	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
3784
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
3785
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
3786
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
3787 3788 3789 3790 3791
	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)
3792
		goto out_disk;
3793

C
Christoph Hellwig 已提交
3794 3795 3796 3797 3798 3799
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

3800 3801
	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
3802

3803
	/* set io sizes to object size */
A
Alex Elder 已提交
3804 3805
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
3806
	q->limits.max_sectors = queue_max_hw_sectors(q);
3807
	blk_queue_max_segments(q, USHRT_MAX);
3808
	blk_queue_max_segment_size(q, UINT_MAX);
A
Alex Elder 已提交
3809 3810
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
3811

3812 3813 3814
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
3815
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
3816
	blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE);
3817

3818
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
3819
		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
3820

3821 3822 3823 3824 3825
	/*
	 * 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));
3826 3827 3828 3829 3830 3831
	disk->queue = q;
	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
3832 3833
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
3834 3835
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
3836
	return err;
3837 3838
}

3839 3840 3841 3842
/*
  sysfs
*/

A
Alex Elder 已提交
3843 3844 3845 3846 3847
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

3848 3849 3850
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3851
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3852

A
Alex Elder 已提交
3853 3854
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
3855 3856
}

A
Alex Elder 已提交
3857 3858 3859 3860 3861 3862 3863 3864 3865 3866
/*
 * 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
3867
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
3868 3869
}

3870 3871 3872
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3873
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3874

A
Alex Elder 已提交
3875 3876 3877 3878
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
3879 3880 3881 3882 3883 3884
}

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
3885

3886
	return sprintf(buf, "%d\n", rbd_dev->minor);
3887 3888
}

3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899
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));
}

3900 3901
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
3902
{
A
Alex Elder 已提交
3903
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3904

3905
	return sprintf(buf, "client%lld\n",
3906
		       ceph_client_gid(rbd_dev->rbd_client->client));
3907 3908
}

3909 3910 3911 3912 3913 3914 3915 3916
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);
}

3917 3918 3919 3920 3921 3922
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);
3923 3924
}

3925 3926
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
3927
{
A
Alex Elder 已提交
3928
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3929

3930
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3931 3932
}

3933 3934 3935 3936 3937
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);

3938
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
3939
			(unsigned long long) rbd_dev->spec->pool_id);
3940 3941
}

3942 3943 3944
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3945
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3946

A
Alex Elder 已提交
3947 3948 3949 3950
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
3951 3952
}

A
Alex Elder 已提交
3953 3954 3955 3956 3957
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);

3958
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
3959 3960
}

A
Alex Elder 已提交
3961 3962 3963 3964
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
3965 3966 3967 3968
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
3969
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3970

3971
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3972 3973
}

3974 3975 3976 3977 3978 3979 3980 3981
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);
}

3982
/*
3983 3984 3985
 * 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)".
3986 3987
 */
static ssize_t rbd_parent_show(struct device *dev,
3988 3989
			       struct device_attribute *attr,
			       char *buf)
3990 3991
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3992
	ssize_t count = 0;
3993

3994
	if (!rbd_dev->parent)
3995 3996
		return sprintf(buf, "(no parent image)\n");

3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012
	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;
4013 4014
}

4015 4016 4017 4018 4019
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
4020
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4021
	int ret;
4022

A
Alex Elder 已提交
4023
	ret = rbd_dev_refresh(rbd_dev);
4024
	if (ret)
4025
		return ret;
4026

4027
	return size;
4028
}
4029

4030
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4031
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4032
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4033
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4034
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4035
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4036
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4037
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4038
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4039
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4040
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4041
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4042 4043
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4044
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4045
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4046 4047 4048

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4049
	&dev_attr_features.attr,
4050
	&dev_attr_major.attr,
4051
	&dev_attr_minor.attr,
4052
	&dev_attr_client_addr.attr,
4053
	&dev_attr_client_id.attr,
4054
	&dev_attr_cluster_fsid.attr,
4055
	&dev_attr_config_info.attr,
4056
	&dev_attr_pool.attr,
4057
	&dev_attr_pool_id.attr,
4058
	&dev_attr_name.attr,
A
Alex Elder 已提交
4059
	&dev_attr_image_id.attr,
4060
	&dev_attr_current_snap.attr,
4061
	&dev_attr_snap_id.attr,
4062
	&dev_attr_parent.attr,
4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075
	&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
};

4076
static void rbd_dev_release(struct device *dev);
4077

4078
static const struct device_type rbd_device_type = {
4079 4080
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4081
	.release	= rbd_dev_release,
4082 4083
};

4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104
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;
4105 4106 4107

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123
	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);
}

4124
static void rbd_dev_free(struct rbd_device *rbd_dev)
4125
{
4126
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4127
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4128

4129
	ceph_oid_destroy(&rbd_dev->header_oid);
4130
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4131
	kfree(rbd_dev->config_info);
4132

4133 4134 4135 4136
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149
}

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);
4150 4151 4152 4153 4154 4155 4156 4157 4158 4159

	/*
	 * 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);
}

4160 4161
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4162 4163 4164
{
	struct rbd_device *rbd_dev;

4165
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4166 4167 4168 4169 4170 4171 4172
	if (!rbd_dev)
		return NULL;

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

4173
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4174
	ceph_oid_init(&rbd_dev->header_oid);
4175
	rbd_dev->header_oloc.pool = spec->pool_id;
4176

4177 4178 4179 4180
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4181 4182 4183 4184 4185 4186 4187 4188
	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);

4189 4190 4191 4192 4193
	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);

4194
	rbd_dev->rbd_client = rbdc;
4195
	rbd_dev->spec = spec;
4196

4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226
	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;
4227

4228 4229
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4230

4231
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4232
	return rbd_dev;
4233 4234 4235 4236 4237 4238

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4239 4240 4241 4242
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4243 4244
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4245 4246
}

4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261
/*
 * 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 };

4262 4263 4264 4265
	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));
4266
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4267 4268
	if (ret < 0)
		return ret;
4269 4270
	if (ret < sizeof (size_buf))
		return -ERANGE;
4271

J
Josh Durgin 已提交
4272
	if (order) {
4273
		*order = size_buf.order;
J
Josh Durgin 已提交
4274 4275
		dout("  order %u", (unsigned int)*order);
	}
4276 4277
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4278 4279
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4280
		(unsigned long long)*snap_size);
4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291

	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);
}

4292 4293 4294 4295 4296 4297 4298 4299 4300 4301
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;

4302 4303 4304
	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);
4305
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4306 4307 4308 4309 4310
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4311 4312
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325

	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;
}

4326 4327 4328 4329 4330 4331 4332
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;
4333
	} __attribute__ ((packed)) features_buf = { 0 };
4334
	u64 unsup;
4335 4336
	int ret;

4337 4338 4339 4340
	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));
4341
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4342 4343
	if (ret < 0)
		return ret;
4344 4345
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4346

4347 4348 4349 4350
	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
4351
		return -ENXIO;
4352
	}
A
Alex Elder 已提交
4353

4354 4355 4356
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4357 4358 4359
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4360 4361 4362 4363 4364 4365 4366 4367 4368 4369

	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);
}

4370 4371 4372 4373 4374 4375 4376 4377
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
4378
	u64 pool_id;
4379
	char *image_id;
4380
	u64 snap_id;
4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397
	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;
	}

4398
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4399 4400 4401
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
4402
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4403 4404 4405 4406
	if (ret < 0)
		goto out_err;

	p = reply_buf;
4407 4408
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
4409
	ceph_decode_64_safe(&p, end, pool_id, out_err);
4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426
	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);
		}

4427
		goto out;	/* No parent?  No problem. */
4428
	}
4429

4430 4431 4432
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
4433
	if (pool_id > (u64)U32_MAX) {
4434
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
4435
			(unsigned long long)pool_id, U32_MAX);
4436
		goto out_err;
A
Alex Elder 已提交
4437
	}
4438

A
Alex Elder 已提交
4439
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4440 4441 4442 4443
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
4444
	ceph_decode_64_safe(&p, end, snap_id, out_err);
4445 4446
	ceph_decode_64_safe(&p, end, overlap, out_err);

4447 4448 4449 4450 4451 4452 4453 4454 4455
	/*
	 * 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
4456 4457
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
4458 4459
	} else {
		kfree(image_id);
4460 4461 4462
	}

	/*
4463 4464
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
4465 4466 4467
	 */
	if (!overlap) {
		if (parent_spec) {
4468 4469 4470 4471
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
4472
		} else {
4473 4474
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
4475
		}
A
Alex Elder 已提交
4476
	}
4477 4478
	rbd_dev->parent_overlap = overlap;

4479 4480 4481 4482 4483 4484 4485 4486 4487
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500
static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
{
	struct {
		__le64 stripe_unit;
		__le64 stripe_count;
	} __attribute__ ((packed)) striping_info_buf = { 0 };
	size_t size = sizeof (striping_info_buf);
	void *p;
	u64 obj_size;
	u64 stripe_unit;
	u64 stripe_count;
	int ret;

4501 4502 4503
	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);
4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
	if (ret < 0)
		return ret;
	if (ret < size)
		return -ERANGE;

	/*
	 * We don't actually support the "fancy striping" feature
	 * (STRIPINGV2) yet, but if the striping sizes are the
	 * defaults the behavior is the same as before.  So find
	 * out, and only fail if the image has non-default values.
	 */
	ret = -EINVAL;
I
Ilya Dryomov 已提交
4517
	obj_size = rbd_obj_bytes(&rbd_dev->header);
4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531
	p = &striping_info_buf;
	stripe_unit = ceph_decode_64(&p);
	if (stripe_unit != obj_size) {
		rbd_warn(rbd_dev, "unsupported stripe unit "
				"(got %llu want %llu)",
				stripe_unit, obj_size);
		return -EINVAL;
	}
	stripe_count = ceph_decode_64(&p);
	if (stripe_count != 1) {
		rbd_warn(rbd_dev, "unsupported stripe count "
				"(got %llu want 1)", stripe_count);
		return -EINVAL;
	}
4532 4533
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
4534 4535 4536 4537

	return 0;
}

4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555
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;
}

4556 4557
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
4558
	CEPH_DEFINE_OID_ONSTACK(oid);
4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570
	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
4571 4572
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
4573 4574 4575 4576 4577
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
4578
	end = image_id + image_id_size;
4579
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
4580 4581 4582 4583 4584 4585

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

4586 4587 4588 4589
	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);
4590 4591 4592
	if (ret < 0)
		goto out;
	p = reply_buf;
4593 4594
	end = reply_buf + ret;

4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606
	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;
}

4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636
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);
4637 4638 4639 4640 4641 4642 4643
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661
		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);
}

4662
/*
4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689
 * 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.
4690
 *
4691 4692
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
4693
 */
4694
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
4695
{
4696 4697 4698 4699 4700
	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;
4701 4702
	int ret;

4703 4704 4705
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
4706

4707
	/* Get the pool name; we have to make our own copy of this */
4708

4709 4710 4711
	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);
4712 4713
		return -EIO;
	}
4714 4715
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
4716 4717 4718 4719
		return -ENOMEM;

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

4720 4721
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
4722
		rbd_warn(rbd_dev, "unable to get image name");
4723

4724
	/* Fetch the snapshot name */
4725

4726
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4727 4728
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
4729
		goto out_err;
4730 4731 4732 4733 4734
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
4735 4736

	return 0;
4737

4738
out_err:
4739 4740
	kfree(image_name);
	kfree(pool_name);
4741 4742 4743
	return ret;
}

A
Alex Elder 已提交
4744
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767
{
	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;

4768 4769 4770
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
4771
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4772 4773 4774 4775
	if (ret < 0)
		goto out;

	p = reply_buf;
4776 4777
	end = reply_buf + ret;
	ret = -ERANGE;
4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793
	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;
4794
	ret = 0;
4795

4796
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4797 4798 4799 4800 4801 4802 4803 4804
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

4805
	ceph_put_snap_context(rbd_dev->header.snapc);
4806 4807 4808
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
4809
		(unsigned long long)seq, (unsigned int)snap_count);
4810 4811 4812
out:
	kfree(reply_buf);

4813
	return ret;
4814 4815
}

4816 4817
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
4818 4819 4820
{
	size_t size;
	void *reply_buf;
4821
	__le64 snapid;
A
Alex Elder 已提交
4822 4823 4824 4825 4826 4827 4828 4829 4830 4831
	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);

4832
	snapid = cpu_to_le64(snap_id);
4833 4834 4835
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
4836
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4837 4838
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
4839
		goto out;
4840
	}
A
Alex Elder 已提交
4841 4842

	p = reply_buf;
4843
	end = reply_buf + ret;
A
Alex Elder 已提交
4844
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4845
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
4846 4847
		goto out;

4848
	dout("  snap_id 0x%016llx snap_name = %s\n",
4849
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
4850 4851 4852
out:
	kfree(reply_buf);

4853
	return snap_name;
A
Alex Elder 已提交
4854 4855
}

4856
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4857
{
4858
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
4859 4860
	int ret;

4861 4862
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
4863
		return ret;
4864

4865 4866 4867
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
4868
			return ret;
4869 4870
	}

A
Alex Elder 已提交
4871
	ret = rbd_dev_v2_snap_context(rbd_dev);
4872 4873 4874 4875
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
4876 4877 4878 4879

	return ret;
}

4880 4881 4882 4883 4884 4885 4886 4887 4888 4889
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);
}

4890 4891 4892
/*
 * 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
4893 4894
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908
 */
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
4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930
/*
 * 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
4931
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

4943
/*
4944 4945 4946 4947
 * 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
4948
 *
4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982
 * 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.
4983
 */
4984
static int rbd_add_parse_args(const char *buf,
4985
				struct ceph_options **ceph_opts,
4986 4987
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
4988
{
A
Alex Elder 已提交
4989
	size_t len;
4990
	char *options;
4991
	const char *mon_addrs;
4992
	char *snap_name;
4993
	size_t mon_addrs_size;
4994
	struct rbd_spec *spec = NULL;
4995
	struct rbd_options *rbd_opts = NULL;
4996
	struct ceph_options *copts;
4997
	int ret;
4998 4999 5000

	/* The first four tokens are required */

5001
	len = next_token(&buf);
5002 5003 5004 5005
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5006
	mon_addrs = buf;
5007
	mon_addrs_size = len + 1;
5008
	buf += len;
5009

5010
	ret = -EINVAL;
5011 5012
	options = dup_token(&buf, NULL);
	if (!options)
5013
		return -ENOMEM;
5014 5015 5016 5017
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5018

5019 5020
	spec = rbd_spec_alloc();
	if (!spec)
5021
		goto out_mem;
5022 5023 5024 5025

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5026 5027 5028 5029
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5030

A
Alex Elder 已提交
5031
	spec->image_name = dup_token(&buf, NULL);
5032
	if (!spec->image_name)
5033
		goto out_mem;
5034 5035 5036 5037
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5038

5039 5040 5041 5042
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5043
	len = next_token(&buf);
5044
	if (!len) {
5045 5046
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5047
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5048
		ret = -ENAMETOOLONG;
5049
		goto out_err;
5050
	}
5051 5052
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5053
		goto out_mem;
5054 5055
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5056

5057
	/* Initialize all rbd options to the defaults */
5058

5059 5060 5061 5062 5063
	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
5064
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5065
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
I
Ilya Dryomov 已提交
5066
	rbd_opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
A
Alex Elder 已提交
5067

5068
	copts = ceph_parse_options(options, mon_addrs,
5069
					mon_addrs + mon_addrs_size - 1,
5070
					parse_rbd_opts_token, rbd_opts);
5071 5072
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5073 5074
		goto out_err;
	}
5075 5076 5077
	kfree(options);

	*ceph_opts = copts;
5078
	*opts = rbd_opts;
5079
	*rbd_spec = spec;
5080

5081
	return 0;
5082
out_mem:
5083
	ret = -ENOMEM;
A
Alex Elder 已提交
5084
out_err:
5085 5086
	kfree(rbd_opts);
	rbd_spec_put(spec);
5087
	kfree(options);
A
Alex Elder 已提交
5088

5089
	return ret;
5090 5091
}

5092 5093 5094 5095 5096
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5097
	struct ceph_options *opts = rbdc->client->options;
5098 5099 5100 5101 5102 5103 5104
	u64 newest_epoch;
	int tries = 0;
	int ret;

again:
	ret = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, pool_name);
	if (ret == -ENOENT && tries++ < 1) {
5105 5106
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5107 5108 5109 5110
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5111
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5112
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5113 5114
						     newest_epoch,
						     opts->mount_timeout);
5115 5116 5117 5118 5119 5120 5121 5122 5123 5124
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

I
Ilya Dryomov 已提交
5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151
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
5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169
/*
 * 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;
5170
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5171
	void *response;
5172
	char *image_id;
5173

A
Alex Elder 已提交
5174 5175 5176
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5177 5178
	 * 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
5179
	 */
5180 5181 5182
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5183
		return 0;
5184
	}
A
Alex Elder 已提交
5185

A
Alex Elder 已提交
5186 5187 5188 5189
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5190 5191 5192 5193 5194 5195
	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
5196 5197 5198 5199 5200 5201 5202 5203 5204 5205

	/* 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;
	}

5206 5207
	/* If it doesn't exist we'll assume it's a format 1 image */

5208 5209 5210
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5211
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5212 5213 5214 5215 5216
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5217
	} else if (ret >= 0) {
5218 5219 5220
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5221
						NULL, GFP_NOIO);
5222
		ret = PTR_ERR_OR_ZERO(image_id);
5223 5224 5225 5226 5227 5228 5229
		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
5230 5231 5232
	}
out:
	kfree(response);
5233
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5234 5235 5236
	return ret;
}

A
Alex Elder 已提交
5237 5238 5239 5240
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5241 5242 5243 5244
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5245
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5246 5247 5248 5249

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

	header = &rbd_dev->header;
5250
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5251 5252 5253 5254 5255 5256
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5257
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5258 5259 5260
{
	int ret;

5261
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5262
	if (ret)
5263 5264
		goto out_err;

5265 5266 5267 5268
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5269
	ret = rbd_dev_v2_features(rbd_dev);
5270
	if (ret)
5271
		goto out_err;
5272

5273 5274 5275 5276 5277 5278 5279
	/* 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;
	}
5280

5281 5282 5283 5284 5285 5286
	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
5287
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5288
	return 0;
I
Ilya Dryomov 已提交
5289

5290
out_err:
A
Alex Elder 已提交
5291
	rbd_dev->header.features = 0;
5292 5293
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5294
	return ret;
5295 5296
}

5297 5298 5299 5300 5301 5302
/*
 * @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
5303
{
5304
	struct rbd_device *parent = NULL;
5305 5306 5307 5308 5309
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5310 5311 5312 5313 5314 5315
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5316
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5317 5318
	if (!parent) {
		ret = -ENOMEM;
5319
		goto out_err;
5320 5321 5322 5323 5324 5325 5326 5327
	}

	/*
	 * 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);
5328

5329
	ret = rbd_dev_image_probe(parent, depth);
5330 5331
	if (ret < 0)
		goto out_err;
5332

5333
	rbd_dev->parent = parent;
5334
	atomic_set(&rbd_dev->parent_ref, 1);
5335
	return 0;
5336

5337
out_err:
5338
	rbd_dev_unparent(rbd_dev);
5339
	rbd_dev_destroy(parent);
5340 5341 5342
	return ret;
}

5343 5344 5345 5346 5347 5348 5349 5350 5351
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
5352 5353 5354 5355
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5356
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5357
{
A
Alex Elder 已提交
5358
	int ret;
A
Alex Elder 已提交
5359

5360
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5361

5362 5363 5364
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5365
			goto err_out_unlock;
5366 5367 5368 5369 5370 5371 5372

		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
5373 5374 5375 5376 5377 5378 5379

	/* Set up the blkdev mapping. */

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

5380
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5381 5382
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5383

5384
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5385
	set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only);
5386

5387
	ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
5388
	if (ret)
5389
		goto err_out_mapping;
A
Alex Elder 已提交
5390

5391
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5392
	up_write(&rbd_dev->header_rwsem);
5393
	return 0;
5394

5395 5396
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5397 5398 5399
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5400 5401
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
5402 5403
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5404 5405 5406
	return ret;
}

A
Alex Elder 已提交
5407 5408 5409
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
5410
	int ret;
A
Alex Elder 已提交
5411 5412 5413 5414 5415

	/* 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)
5416 5417
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
5418
	else
5419 5420
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
5421

5422
	return ret;
A
Alex Elder 已提交
5423 5424
}

5425 5426
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5427
	rbd_dev_unprobe(rbd_dev);
5428 5429
	if (rbd_dev->opts)
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5430 5431 5432
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5433 5434
}

5435 5436
/*
 * Probe for the existence of the header object for the given rbd
5437 5438 5439
 * 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.
5440
 */
5441
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
5442 5443 5444 5445
{
	int ret;

	/*
A
Alex Elder 已提交
5446 5447 5448 5449
	 * 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.
5450 5451 5452
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
5453 5454
		return ret;

A
Alex Elder 已提交
5455 5456 5457 5458
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

5459
	if (!depth) {
5460
		ret = rbd_register_watch(rbd_dev);
5461 5462 5463 5464 5465
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
5466
			goto err_out_format;
5467
		}
5468
	}
5469

5470
	ret = rbd_dev_header_info(rbd_dev);
5471
	if (ret)
5472
		goto err_out_watch;
A
Alex Elder 已提交
5473

5474 5475 5476 5477 5478 5479
	/*
	 * 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.
	 */
5480
	if (!depth)
5481 5482 5483
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
5484 5485 5486 5487 5488 5489
	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
5490
		goto err_out_probe;
5491
	}
5492

5493 5494 5495 5496 5497 5498 5499 5500 5501
	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.
		 */
5502
		if (!depth && rbd_dev->parent_spec)
5503 5504 5505 5506
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

5507
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
5508 5509 5510 5511
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
5512
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
5513
	return 0;
5514

A
Alex Elder 已提交
5515 5516
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
5517
err_out_watch:
5518
	if (!depth)
5519
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
5520 5521
err_out_format:
	rbd_dev->image_format = 0;
5522 5523
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5524 5525 5526
	return ret;
}

5527 5528 5529
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
5530
{
5531
	struct rbd_device *rbd_dev = NULL;
5532
	struct ceph_options *ceph_opts = NULL;
5533
	struct rbd_options *rbd_opts = NULL;
5534
	struct rbd_spec *spec = NULL;
5535
	struct rbd_client *rbdc;
5536
	int rc;
5537 5538 5539 5540 5541

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

	/* parse add command */
5542
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
5543
	if (rc < 0)
5544
		goto out;
5545

5546 5547 5548
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
5549
		goto err_out_args;
5550
	}
5551 5552

	/* pick the pool */
5553
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
5554 5555 5556
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
5557
		goto err_out_client;
5558
	}
A
Alex Elder 已提交
5559
	spec->pool_id = (u64)rc;
5560

5561
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
5562 5563
	if (!rbd_dev) {
		rc = -ENOMEM;
5564
		goto err_out_client;
5565
	}
5566 5567
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
5568
	rbd_opts = NULL;	/* rbd_dev now owns this */
5569

5570 5571 5572 5573 5574 5575
	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
5576
	down_write(&rbd_dev->header_rwsem);
5577
	rc = rbd_dev_image_probe(rbd_dev, 0);
5578 5579
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
5580
		goto err_out_rbd_dev;
5581
	}
5582

5583 5584
	/* If we are mapping a snapshot it must be marked read-only */
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
5585
		rbd_dev->opts->read_only = true;
5586

5587
	rc = rbd_dev_device_setup(rbd_dev);
5588
	if (rc)
5589
		goto err_out_image_probe;
A
Alex Elder 已提交
5590

I
Ilya Dryomov 已提交
5591 5592 5593 5594
	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
5595 5596
	}

5597 5598 5599 5600
	/* Everything's ready.  Announce the disk to the world. */

	rc = device_add(&rbd_dev->dev);
	if (rc)
I
Ilya Dryomov 已提交
5601
		goto err_out_image_lock;
5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613

	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);
5614 5615 5616 5617
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
5618

I
Ilya Dryomov 已提交
5619 5620
err_out_image_lock:
	rbd_dev_image_unlock(rbd_dev);
5621 5622
err_out_device_setup:
	rbd_dev_device_release(rbd_dev);
5623 5624
err_out_image_probe:
	rbd_dev_image_release(rbd_dev);
5625 5626
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
5627
err_out_client:
5628
	rbd_put_client(rbdc);
5629
err_out_args:
5630
	rbd_spec_put(spec);
5631
	kfree(rbd_opts);
5632
	goto out;
5633 5634
}

5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651
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);
}

5652 5653
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5654
	while (rbd_dev->parent) {
5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666
		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
5667
		rbd_assert(second);
5668
		rbd_dev_image_release(second);
5669
		rbd_dev_destroy(second);
A
Alex Elder 已提交
5670 5671 5672 5673
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
5674 5675 5676 5677 5678
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

5679 5680 5681
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
5682 5683
{
	struct rbd_device *rbd_dev = NULL;
5684 5685
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
5686
	char opt_buf[6];
5687
	bool already = false;
M
Mike Christie 已提交
5688
	bool force = false;
5689
	int ret;
5690

M
Mike Christie 已提交
5691 5692 5693 5694 5695
	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");
5696
		return -EINVAL;
M
Mike Christie 已提交
5697 5698 5699 5700 5701 5702 5703 5704 5705
	}
	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;
		}
	}
5706

5707 5708 5709 5710 5711 5712 5713 5714
	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;
		}
5715
	}
5716 5717
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
5718
		if (rbd_dev->open_count && !force)
5719 5720
			ret = -EBUSY;
		else
5721 5722
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
5723 5724 5725
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
5726
	if (ret < 0 || already)
5727
		return ret;
5728

M
Mike Christie 已提交
5729 5730 5731 5732 5733 5734 5735 5736 5737
	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);
	}

5738 5739 5740 5741 5742
	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);
5743

I
Ilya Dryomov 已提交
5744
	rbd_dev_image_unlock(rbd_dev);
5745
	rbd_dev_device_release(rbd_dev);
5746
	rbd_dev_image_release(rbd_dev);
5747
	rbd_dev_destroy(rbd_dev);
5748
	return count;
5749 5750
}

5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767
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);
}

5768 5769
/*
 * create control files in sysfs
5770
 * /sys/bus/rbd/...
5771 5772 5773
 */
static int rbd_sysfs_init(void)
{
5774
	int ret;
5775

5776
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
5777
	if (ret < 0)
5778
		return ret;
5779

5780 5781 5782
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
5783 5784 5785 5786 5787 5788

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
5789
	bus_unregister(&rbd_bus_type);
5790
	device_unregister(&rbd_root_dev);
5791 5792
}

5793 5794 5795
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
5796
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
5797 5798 5799 5800
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
5801
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
5802 5803 5804
	if (!rbd_obj_request_cache)
		goto out_err;

5805
	return 0;
5806

5807
out_err:
5808 5809
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
5810 5811 5812 5813 5814
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
5815 5816 5817 5818
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

5819 5820 5821 5822 5823
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
5824
static int __init rbd_init(void)
5825 5826 5827
{
	int rc;

5828 5829 5830 5831
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
5832

5833
	rc = rbd_slab_init();
5834 5835
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
5836

5837 5838
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
5839
	 * rbd devices * queue depth, so leave @max_active at default.
5840 5841 5842 5843 5844 5845 5846
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

5847 5848 5849 5850
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
5851
			goto err_out_wq;
5852 5853 5854
		}
	}

5855 5856
	rc = rbd_sysfs_init();
	if (rc)
5857 5858 5859 5860 5861 5862
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
5863

I
Ilya Dryomov 已提交
5864 5865
	return 0;

5866 5867 5868
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
5869 5870
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
5871 5872
err_out_slab:
	rbd_slab_exit();
5873
	return rc;
5874 5875
}

A
Alex Elder 已提交
5876
static void __exit rbd_exit(void)
5877
{
I
Ilya Dryomov 已提交
5878
	ida_destroy(&rbd_dev_id_ida);
5879
	rbd_sysfs_cleanup();
5880 5881
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
5882
	destroy_workqueue(rbd_wq);
5883
	rbd_slab_exit();
5884 5885 5886 5887 5888
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
5889
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
5890 5891 5892 5893 5894
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>");

5895
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
5896
MODULE_LICENSE("GPL");