rbd.c 165.9 KB
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/*
   rbd.c -- Export ceph rados objects as a Linux block device


   based on drivers/block/osdblk.c:

   Copyright 2009 Red Hat, Inc.

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

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

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



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

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

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

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

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

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

	atomic_dec(v);

	return -EINVAL;
}

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

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

	atomic_inc(v);

	return -EINVAL;
}

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

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

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

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

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

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/* Feature bits */

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#define RBD_FEATURE_LAYERING	(1<<0)
#define RBD_FEATURE_STRIPINGV2	(1<<1)
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#define RBD_FEATURE_EXCLUSIVE_LOCK (1<<2)
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#define RBD_FEATURE_DATA_POOL (1<<7)
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#define RBD_FEATURES_ALL	(RBD_FEATURE_LAYERING |		\
				 RBD_FEATURE_STRIPINGV2 |	\
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				 RBD_FEATURE_EXCLUSIVE_LOCK |	\
				 RBD_FEATURE_DATA_POOL)
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/* Features supported by this (client software) implementation. */

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#define RBD_FEATURES_SUPPORTED	(RBD_FEATURES_ALL)
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/*
 * An RBD device name will be "rbd#", where the "rbd" comes from
 * RBD_DRV_NAME above, and # is a unique integer identifier.
 */
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#define DEV_NAME_LEN		32

/*
 * block device image metadata (in-memory version)
 */
struct rbd_image_header {
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	/* These six fields never change for a given rbd image */
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	char *object_prefix;
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	__u8 obj_order;
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	u64 stripe_unit;
	u64 stripe_count;
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	s64 data_pool_id;
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	u64 features;		/* Might be changeable someday? */
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	/* The remaining fields need to be updated occasionally */
	u64 image_size;
	struct ceph_snap_context *snapc;
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	char *snap_names;	/* format 1 only */
	u64 *snap_sizes;	/* format 1 only */
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};

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/*
 * An rbd image specification.
 *
 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
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 * identify an image.  Each rbd_dev structure includes a pointer to
 * an rbd_spec structure that encapsulates this identity.
 *
 * Each of the id's in an rbd_spec has an associated name.  For a
 * user-mapped image, the names are supplied and the id's associated
 * with them are looked up.  For a layered image, a parent image is
 * defined by the tuple, and the names are looked up.
 *
 * An rbd_dev structure contains a parent_spec pointer which is
 * non-null if the image it represents is a child in a layered
 * image.  This pointer will refer to the rbd_spec structure used
 * by the parent rbd_dev for its own identity (i.e., the structure
 * is shared between the parent and child).
 *
 * Since these structures are populated once, during the discovery
 * phase of image construction, they are effectively immutable so
 * we make no effort to synchronize access to them.
 *
 * Note that code herein does not assume the image name is known (it
 * could be a null pointer).
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 */
struct rbd_spec {
	u64		pool_id;
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	const char	*pool_name;
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	const char	*image_id;
	const char	*image_name;
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	u64		snap_id;
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	const char	*snap_name;
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	struct kref	kref;
};

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/*
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 * an instance of the client.  multiple devices may share an rbd client.
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 */
struct rbd_client {
	struct ceph_client	*client;
	struct kref		kref;
	struct list_head	node;
};

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struct rbd_img_request;
typedef void (*rbd_img_callback_t)(struct rbd_img_request *);

#define	BAD_WHICH	U32_MAX		/* Good which or bad which, which? */

struct rbd_obj_request;
typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);

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enum obj_request_type {
	OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
};
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enum obj_operation_type {
	OBJ_OP_WRITE,
	OBJ_OP_READ,
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	OBJ_OP_DISCARD,
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};

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enum obj_req_flags {
	OBJ_REQ_DONE,		/* completion flag: not done = 0, done = 1 */
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	OBJ_REQ_IMG_DATA,	/* object usage: standalone = 0, image = 1 */
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	OBJ_REQ_KNOWN,		/* EXISTS flag valid: no = 0, yes = 1 */
	OBJ_REQ_EXISTS,		/* target exists: no = 0, yes = 1 */
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};

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struct rbd_obj_request {
	const char		*object_name;
	u64			offset;		/* object start byte */
	u64			length;		/* bytes from offset */
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	unsigned long		flags;
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	/*
	 * An object request associated with an image will have its
	 * img_data flag set; a standalone object request will not.
	 *
	 * A standalone object request will have which == BAD_WHICH
	 * and a null obj_request pointer.
	 *
	 * An object request initiated in support of a layered image
	 * object (to check for its existence before a write) will
	 * have which == BAD_WHICH and a non-null obj_request pointer.
	 *
	 * Finally, an object request for rbd image data will have
	 * which != BAD_WHICH, and will have a non-null img_request
	 * pointer.  The value of which will be in the range
	 * 0..(img_request->obj_request_count-1).
	 */
	union {
		struct rbd_obj_request	*obj_request;	/* STAT op */
		struct {
			struct rbd_img_request	*img_request;
			u64			img_offset;
			/* links for img_request->obj_requests list */
			struct list_head	links;
		};
	};
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	u32			which;		/* posn image request list */

	enum obj_request_type	type;
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	union {
		struct bio	*bio_list;
		struct {
			struct page	**pages;
			u32		page_count;
		};
	};
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	struct page		**copyup_pages;
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	u32			copyup_page_count;
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	struct ceph_osd_request	*osd_req;

	u64			xferred;	/* bytes transferred */
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	int			result;
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	rbd_obj_callback_t	callback;
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	struct completion	completion;
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	struct kref		kref;
};

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enum img_req_flags {
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	IMG_REQ_WRITE,		/* I/O direction: read = 0, write = 1 */
	IMG_REQ_CHILD,		/* initiator: block = 0, child image = 1 */
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	IMG_REQ_LAYERED,	/* ENOENT handling: normal = 0, layered = 1 */
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	IMG_REQ_DISCARD,	/* discard: normal = 0, discard request = 1 */
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};

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struct rbd_img_request {
	struct rbd_device	*rbd_dev;
	u64			offset;	/* starting image byte offset */
	u64			length;	/* byte count from offset */
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	unsigned long		flags;
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	union {
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		u64			snap_id;	/* for reads */
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		struct ceph_snap_context *snapc;	/* for writes */
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	};
	union {
		struct request		*rq;		/* block request */
		struct rbd_obj_request	*obj_request;	/* obj req initiator */
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	};
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	struct page		**copyup_pages;
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	u32			copyup_page_count;
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	spinlock_t		completion_lock;/* protects next_completion */
	u32			next_completion;
	rbd_img_callback_t	callback;
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	u64			xferred;/* aggregate bytes transferred */
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	int			result;	/* first nonzero obj_request result */
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	u32			obj_request_count;
	struct list_head	obj_requests;	/* rbd_obj_request structs */

	struct kref		kref;
};

#define for_each_obj_request(ireq, oreq) \
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	list_for_each_entry(oreq, &(ireq)->obj_requests, links)
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#define for_each_obj_request_from(ireq, oreq) \
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	list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
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#define for_each_obj_request_safe(ireq, oreq, n) \
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	list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
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enum rbd_watch_state {
	RBD_WATCH_STATE_UNREGISTERED,
	RBD_WATCH_STATE_REGISTERED,
	RBD_WATCH_STATE_ERROR,
};

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enum rbd_lock_state {
	RBD_LOCK_STATE_UNLOCKED,
	RBD_LOCK_STATE_LOCKED,
	RBD_LOCK_STATE_RELEASING,
};

/* WatchNotify::ClientId */
struct rbd_client_id {
	u64 gid;
	u64 handle;
};

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struct rbd_mapping {
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	u64                     size;
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	u64                     features;
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	bool			read_only;
};

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/*
 * a single device
 */
struct rbd_device {
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	int			dev_id;		/* blkdev unique id */
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	int			major;		/* blkdev assigned major */
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	int			minor;
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	struct gendisk		*disk;		/* blkdev's gendisk and rq */

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	u32			image_format;	/* Either 1 or 2 */
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	struct rbd_client	*rbd_client;

	char			name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */

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	spinlock_t		lock;		/* queue, flags, open_count */
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	struct rbd_image_header	header;
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	unsigned long		flags;		/* possibly lock protected */
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	struct rbd_spec		*spec;
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	struct rbd_options	*opts;
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	char			*config_info;	/* add{,_single_major} string */
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	struct ceph_object_id	header_oid;
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	struct ceph_object_locator header_oloc;
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	struct ceph_file_layout	layout;		/* used for all rbd requests */
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	struct mutex		watch_mutex;
	enum rbd_watch_state	watch_state;
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	struct ceph_osd_linger_request *watch_handle;
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	u64			watch_cookie;
	struct delayed_work	watch_dwork;
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	struct rw_semaphore	lock_rwsem;
	enum rbd_lock_state	lock_state;
	struct rbd_client_id	owner_cid;
	struct work_struct	acquired_lock_work;
	struct work_struct	released_lock_work;
	struct delayed_work	lock_dwork;
	struct work_struct	unlock_work;
	wait_queue_head_t	lock_waitq;

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

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

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/*
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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 struct kmem_cache	*rbd_segment_name_cache;
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static int rbd_major;
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static DEFINE_IDA(rbd_dev_id_ida);

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static struct workqueue_struct *rbd_wq;

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/*
 * Default to false for now, as single-major requires >= 0.75 version of
 * userspace rbd utility.
 */
static bool single_major = false;
module_param(single_major, bool, S_IRUGO);
MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: false)");

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static int rbd_img_request_submit(struct rbd_img_request *img_request);

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static ssize_t rbd_add(struct bus_type *bus, const char *buf,
		       size_t count);
static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
			  size_t count);
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static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf,
				    size_t count);
static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
				       size_t count);
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static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
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static void rbd_spec_put(struct rbd_spec *spec);
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static int rbd_dev_id_to_minor(int dev_id)
{
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	return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
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}

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

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static bool rbd_is_lock_supported(struct rbd_device *rbd_dev)
{
	return (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	       rbd_dev->spec->snap_id == CEPH_NOSNAP &&
	       !rbd_dev->mapping.read_only;
}

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

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

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

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

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	return attr->mode;
}

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

static void rbd_root_dev_release(struct device *dev)
{
}

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

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

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

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

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#ifdef RBD_DEBUG
#define rbd_assert(expr)						\
		if (unlikely(!(expr))) {				\
			printk(KERN_ERR "\nAssertion failure in %s() "	\
						"at line %d:\n\n"	\
					"\trbd_assert(%s);\n\n",	\
					__func__, __LINE__, #expr);	\
			BUG();						\
		}
#else /* !RBD_DEBUG */
#  define rbd_assert(expr)	((void) 0)
#endif /* !RBD_DEBUG */
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static void rbd_osd_copyup_callback(struct rbd_obj_request *obj_request);
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static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
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static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
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static int rbd_dev_refresh(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
594
static int rbd_dev_header_info(struct rbd_device *rbd_dev);
595
static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
596 597
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id);
598 599 600 601
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);
602

603 604
static int rbd_open(struct block_device *bdev, fmode_t mode)
{
A
Alex Elder 已提交
605
	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
606
	bool removing = false;
607

A
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608
	if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
609 610
		return -EROFS;

611
	spin_lock_irq(&rbd_dev->lock);
612 613 614 615
	if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
		removing = true;
	else
		rbd_dev->open_count++;
616
	spin_unlock_irq(&rbd_dev->lock);
617 618 619
	if (removing)
		return -ENOENT;

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620
	(void) get_device(&rbd_dev->dev);
621

622 623 624
	return 0;
}

625
static void rbd_release(struct gendisk *disk, fmode_t mode)
626 627
{
	struct rbd_device *rbd_dev = disk->private_data;
628 629
	unsigned long open_count_before;

630
	spin_lock_irq(&rbd_dev->lock);
631
	open_count_before = rbd_dev->open_count--;
632
	spin_unlock_irq(&rbd_dev->lock);
633
	rbd_assert(open_count_before > 0);
634

A
Alex Elder 已提交
635
	put_device(&rbd_dev->dev);
636 637
}

G
Guangliang Zhao 已提交
638 639
static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
640
	int ret = 0;
G
Guangliang Zhao 已提交
641 642
	int val;
	bool ro;
643
	bool ro_changed = false;
G
Guangliang Zhao 已提交
644

645
	/* get_user() may sleep, so call it before taking rbd_dev->lock */
G
Guangliang Zhao 已提交
646 647 648 649 650 651 652 653
	if (get_user(val, (int __user *)(arg)))
		return -EFAULT;

	ro = val ? true : false;
	/* Snapshot doesn't allow to write*/
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
		return -EROFS;

654 655 656 657 658 659 660
	spin_lock_irq(&rbd_dev->lock);
	/* prevent others open this device */
	if (rbd_dev->open_count > 1) {
		ret = -EBUSY;
		goto out;
	}

G
Guangliang Zhao 已提交
661 662
	if (rbd_dev->mapping.read_only != ro) {
		rbd_dev->mapping.read_only = ro;
663
		ro_changed = true;
G
Guangliang Zhao 已提交
664 665
	}

666 667 668 669 670 671 672
out:
	spin_unlock_irq(&rbd_dev->lock);
	/* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
	if (ret == 0 && ro_changed)
		set_disk_ro(rbd_dev->disk, ro ? 1 : 0);

	return ret;
G
Guangliang Zhao 已提交
673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
}

static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
			unsigned int cmd, unsigned long arg)
{
	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
	int ret = 0;

	switch (cmd) {
	case BLKROSET:
		ret = rbd_ioctl_set_ro(rbd_dev, arg);
		break;
	default:
		ret = -ENOTTY;
	}

	return ret;
}

#ifdef CONFIG_COMPAT
static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
				unsigned int cmd, unsigned long arg)
{
	return rbd_ioctl(bdev, mode, cmd, arg);
}
#endif /* CONFIG_COMPAT */

700 701 702
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
703
	.release		= rbd_release,
G
Guangliang Zhao 已提交
704 705 706 707
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
708 709 710
};

/*
711
 * Initialize an rbd client instance.  Success or not, this function
712
 * consumes ceph_opts.  Caller holds client_mutex.
713
 */
714
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
715 716 717 718
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

A
Alex Elder 已提交
719
	dout("%s:\n", __func__);
720 721 722 723 724 725 726
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

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

A
Alex Elder 已提交
727
	rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
728
	if (IS_ERR(rbdc->client))
729
		goto out_rbdc;
A
Alex Elder 已提交
730
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
731 732 733

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
734
		goto out_client;
735

A
Alex Elder 已提交
736
	spin_lock(&rbd_client_list_lock);
737
	list_add_tail(&rbdc->node, &rbd_client_list);
A
Alex Elder 已提交
738
	spin_unlock(&rbd_client_list_lock);
739

A
Alex Elder 已提交
740
	dout("%s: rbdc %p\n", __func__, rbdc);
741

742
	return rbdc;
743
out_client:
744
	ceph_destroy_client(rbdc->client);
745
out_rbdc:
746 747
	kfree(rbdc);
out_opt:
A
Alex Elder 已提交
748 749
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
A
Alex Elder 已提交
750 751
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
752
	return ERR_PTR(ret);
753 754
}

755 756 757 758 759 760 761
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

762
/*
763 764
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
765
 */
766
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
767 768
{
	struct rbd_client *client_node;
769
	bool found = false;
770

A
Alex Elder 已提交
771
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
772 773
		return NULL;

774 775 776
	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)) {
777 778
			__rbd_get_client(client_node);

779 780 781 782 783 784 785
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
786 787
}

788
/*
789
 * (Per device) rbd map options
790 791
 */
enum {
I
Ilya Dryomov 已提交
792
	Opt_queue_depth,
793 794 795 796
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
A
Alex Elder 已提交
797 798
	Opt_read_only,
	Opt_read_write,
I
Ilya Dryomov 已提交
799
	Opt_lock_on_read,
800
	Opt_err
801 802
};

A
Alex Elder 已提交
803
static match_table_t rbd_opts_tokens = {
I
Ilya Dryomov 已提交
804
	{Opt_queue_depth, "queue_depth=%d"},
805 806
	/* int args above */
	/* string args above */
A
Alex Elder 已提交
807
	{Opt_read_only, "read_only"},
A
Alex Elder 已提交
808 809 810
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
I
Ilya Dryomov 已提交
811
	{Opt_lock_on_read, "lock_on_read"},
812
	{Opt_err, NULL}
813 814
};

A
Alex Elder 已提交
815
struct rbd_options {
I
Ilya Dryomov 已提交
816
	int	queue_depth;
A
Alex Elder 已提交
817
	bool	read_only;
I
Ilya Dryomov 已提交
818
	bool	lock_on_read;
A
Alex Elder 已提交
819 820
};

I
Ilya Dryomov 已提交
821
#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
A
Alex Elder 已提交
822
#define RBD_READ_ONLY_DEFAULT	false
I
Ilya Dryomov 已提交
823
#define RBD_LOCK_ON_READ_DEFAULT false
A
Alex Elder 已提交
824

825 826
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
827
	struct rbd_options *rbd_opts = private;
828 829 830
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
Alex Elder 已提交
831
	token = match_token(c, rbd_opts_tokens, argstr);
832 833 834
	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
835
			pr_err("bad mount option arg (not int) at '%s'\n", c);
836 837 838 839
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
840
		dout("got string token %d val %s\n", token, argstr[0].from);
841 842 843 844 845
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
I
Ilya Dryomov 已提交
846 847 848 849 850 851 852
	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
853 854 855 856 857 858
	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
859 860 861
	case Opt_lock_on_read:
		rbd_opts->lock_on_read = true;
		break;
862
	default:
863 864
		/* libceph prints "bad option" msg */
		return -EINVAL;
865
	}
866

867 868 869
	return 0;
}

G
Guangliang Zhao 已提交
870 871 872 873 874 875 876
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";
877 878
	case OBJ_OP_DISCARD:
		return "discard";
G
Guangliang Zhao 已提交
879 880 881 882 883
	default:
		return "???";
	}
}

884 885
/*
 * Get a ceph client with specific addr and configuration, if one does
886 887
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
888
 */
889
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
890
{
891
	struct rbd_client *rbdc;
892

893
	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
894
	rbdc = rbd_client_find(ceph_opts);
895
	if (rbdc)	/* using an existing client */
A
Alex Elder 已提交
896
		ceph_destroy_options(ceph_opts);
897
	else
898
		rbdc = rbd_client_create(ceph_opts);
899
	mutex_unlock(&client_mutex);
900

901
	return rbdc;
902 903 904 905
}

/*
 * Destroy ceph client
A
Alex Elder 已提交
906
 *
A
Alex Elder 已提交
907
 * Caller must hold rbd_client_list_lock.
908 909 910 911 912
 */
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
913
	dout("%s: rbdc %p\n", __func__, rbdc);
914
	spin_lock(&rbd_client_list_lock);
915
	list_del(&rbdc->node);
916
	spin_unlock(&rbd_client_list_lock);
917 918 919 920 921 922 923 924 925

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

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
926
static void rbd_put_client(struct rbd_client *rbdc)
927
{
928 929
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
930 931
}

932 933 934 935 936
static bool rbd_image_format_valid(u32 image_format)
{
	return image_format == 1 || image_format == 2;
}

937 938
static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
{
939 940 941 942 943 944 945
	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
946 947 948 949 950 951 952 953 954 955
	/* 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;

956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973
	/*
	 * 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;
974 975
}

I
Ilya Dryomov 已提交
976 977 978 979 980 981 982 983
/*
 * 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
984 985 986 987 988 989 990 991 992 993 994
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);
995 996
	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
997 998 999
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
}

1000
/*
1001 1002
 * Fill an rbd image header with information from the given format 1
 * on-disk header.
1003
 */
A
Alex Elder 已提交
1004
static int rbd_header_from_disk(struct rbd_device *rbd_dev,
1005
				 struct rbd_image_header_ondisk *ondisk)
1006
{
A
Alex Elder 已提交
1007
	struct rbd_image_header *header = &rbd_dev->header;
1008 1009 1010 1011 1012
	bool first_time = header->object_prefix == NULL;
	struct ceph_snap_context *snapc;
	char *object_prefix = NULL;
	char *snap_names = NULL;
	u64 *snap_sizes = NULL;
1013
	u32 snap_count;
1014
	int ret = -ENOMEM;
1015
	u32 i;
1016

1017
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
1018

1019
	if (first_time) {
1020 1021 1022
		object_prefix = kstrndup(ondisk->object_prefix,
					 sizeof(ondisk->object_prefix),
					 GFP_KERNEL);
1023 1024 1025
		if (!object_prefix)
			return -ENOMEM;
	}
A
Alex Elder 已提交
1026

1027
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
1028

1029 1030 1031 1032 1033
	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);
1034
	if (snap_count) {
1035
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
1036 1037
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

1038
		/* We'll keep a copy of the snapshot names... */
1039

1040 1041 1042 1043
		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
1044 1045
			goto out_err;

1046
		/* ...as well as the array of their sizes. */
1047 1048 1049
		snap_sizes = kmalloc_array(snap_count,
					   sizeof(*header->snap_sizes),
					   GFP_KERNEL);
1050
		if (!snap_sizes)
A
Alex Elder 已提交
1051
			goto out_err;
1052

A
Alex Elder 已提交
1053
		/*
1054 1055 1056
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
1057
		 * Note that rbd_dev_v1_header_info() guarantees the
1058
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
1059 1060 1061
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
1062 1063 1064 1065 1066 1067
		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);
		}
1068
	}
A
Alex Elder 已提交
1069

1070
	/* We won't fail any more, fill in the header */
1071

1072 1073 1074
	if (first_time) {
		header->object_prefix = object_prefix;
		header->obj_order = ondisk->options.order;
I
Ilya Dryomov 已提交
1075
		rbd_init_layout(rbd_dev);
1076
	} else {
A
Alex Elder 已提交
1077 1078 1079
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
1080
	}
1081

1082
	/* The remaining fields always get updated (when we refresh) */
1083

A
Alex Elder 已提交
1084
	header->image_size = le64_to_cpu(ondisk->image_size);
1085 1086 1087
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1088

1089
	return 0;
1090 1091
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1092
out_err:
1093 1094 1095 1096
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1097

1098
	return ret;
1099 1100
}

1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
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);
}

1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
/*
 * 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.
 */
1140 1141 1142
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1143
	u64 *found;
1144

1145 1146
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1147

1148
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1149 1150
}

1151 1152
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1153
{
1154
	u32 which;
1155
	const char *snap_name;
1156

1157 1158
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1159
		return ERR_PTR(-ENOENT);
1160

1161 1162
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1163 1164 1165 1166
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1167 1168 1169
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1170 1171 1172
	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);
1173

1174
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1175 1176
}

1177 1178
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1179
{
1180 1181 1182 1183 1184
	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;
1185

1186 1187 1188
		which = rbd_dev_snap_index(rbd_dev, snap_id);
		if (which == BAD_SNAP_INDEX)
			return -ENOENT;
1189

1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
		*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;
1202 1203
}

1204 1205
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1206
{
1207 1208 1209 1210 1211
	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 */
1212
	} else {
1213 1214
		u64 features = 0;
		int ret;
1215

1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226
		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)
{
1227
	u64 snap_id = rbd_dev->spec->snap_id;
1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241
	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;

1242
	return 0;
1243 1244
}

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1245 1246 1247 1248
static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
{
	rbd_dev->mapping.size = 0;
	rbd_dev->mapping.features = 0;
1249 1250
}

1251 1252 1253 1254 1255 1256 1257
static void rbd_segment_name_free(const char *name)
{
	/* The explicit cast here is needed to drop the const qualifier */

	kmem_cache_free(rbd_segment_name_cache, (void *)name);
}

A
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1258
static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1259
{
A
Alex Elder 已提交
1260 1261 1262
	char *name;
	u64 segment;
	int ret;
1263
	char *name_format;
1264

1265
	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
A
Alex Elder 已提交
1266 1267 1268
	if (!name)
		return NULL;
	segment = offset >> rbd_dev->header.obj_order;
1269 1270 1271
	name_format = "%s.%012llx";
	if (rbd_dev->image_format == 2)
		name_format = "%s.%016llx";
1272
	ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
A
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1273
			rbd_dev->header.object_prefix, segment);
1274
	if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
A
Alex Elder 已提交
1275 1276
		pr_err("error formatting segment name for #%llu (%d)\n",
			segment, ret);
1277
		rbd_segment_name_free(name);
A
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1278 1279
		name = NULL;
	}
1280

A
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1281 1282
	return name;
}
1283

A
Alex Elder 已提交
1284 1285
static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
I
Ilya Dryomov 已提交
1286
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
1287

A
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1288 1289 1290 1291 1292 1293
	return offset & (segment_size - 1);
}

static u64 rbd_segment_length(struct rbd_device *rbd_dev,
				u64 offset, u64 length)
{
I
Ilya Dryomov 已提交
1294
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
A
Alex Elder 已提交
1295 1296 1297

	offset &= segment_size - 1;

A
Alex Elder 已提交
1298
	rbd_assert(length <= U64_MAX - offset);
A
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1299 1300 1301 1302
	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
}

/*
 * bio helpers
 */

static void bio_chain_put(struct bio *chain)
{
	struct bio *tmp;

	while (chain) {
		tmp = chain;
		chain = chain->bi_next;
		bio_put(tmp);
	}
}

/*
 * zeros a bio chain, starting at specific offset
 */
static void zero_bio_chain(struct bio *chain, int start_ofs)
{
1325 1326
	struct bio_vec bv;
	struct bvec_iter iter;
1327 1328 1329 1330 1331
	unsigned long flags;
	void *buf;
	int pos = 0;

	while (chain) {
1332 1333
		bio_for_each_segment(bv, chain, iter) {
			if (pos + bv.bv_len > start_ofs) {
1334
				int remainder = max(start_ofs - pos, 0);
1335
				buf = bvec_kmap_irq(&bv, &flags);
1336
				memset(buf + remainder, 0,
1337 1338
				       bv.bv_len - remainder);
				flush_dcache_page(bv.bv_page);
1339
				bvec_kunmap_irq(buf, &flags);
1340
			}
1341
			pos += bv.bv_len;
1342 1343 1344 1345 1346 1347
		}

		chain = chain->bi_next;
	}
}

A
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1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365
/*
 * similar to zero_bio_chain(), zeros data defined by a page array,
 * starting at the given byte offset from the start of the array and
 * continuing up to the given end offset.  The pages array is
 * assumed to be big enough to hold all bytes up to the end.
 */
static void zero_pages(struct page **pages, u64 offset, u64 end)
{
	struct page **page = &pages[offset >> PAGE_SHIFT];

	rbd_assert(end > offset);
	rbd_assert(end - offset <= (u64)SIZE_MAX);
	while (offset < end) {
		size_t page_offset;
		size_t length;
		unsigned long flags;
		void *kaddr;

1366 1367
		page_offset = offset & ~PAGE_MASK;
		length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
A
Alex Elder 已提交
1368 1369 1370
		local_irq_save(flags);
		kaddr = kmap_atomic(*page);
		memset(kaddr + page_offset, 0, length);
1371
		flush_dcache_page(*page);
A
Alex Elder 已提交
1372 1373 1374 1375 1376 1377 1378 1379
		kunmap_atomic(kaddr);
		local_irq_restore(flags);

		offset += length;
		page++;
	}
}

1380
/*
A
Alex Elder 已提交
1381 1382
 * Clone a portion of a bio, starting at the given byte offset
 * and continuing for the number of bytes indicated.
1383
 */
A
Alex Elder 已提交
1384 1385 1386 1387
static struct bio *bio_clone_range(struct bio *bio_src,
					unsigned int offset,
					unsigned int len,
					gfp_t gfpmask)
1388
{
A
Alex Elder 已提交
1389 1390
	struct bio *bio;

K
Kent Overstreet 已提交
1391
	bio = bio_clone(bio_src, gfpmask);
A
Alex Elder 已提交
1392 1393
	if (!bio)
		return NULL;	/* ENOMEM */
1394

K
Kent Overstreet 已提交
1395
	bio_advance(bio, offset);
1396
	bio->bi_iter.bi_size = len;
A
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1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426

	return bio;
}

/*
 * Clone a portion of a bio chain, starting at the given byte offset
 * into the first bio in the source chain and continuing for the
 * number of bytes indicated.  The result is another bio chain of
 * exactly the given length, or a null pointer on error.
 *
 * The bio_src and offset parameters are both in-out.  On entry they
 * refer to the first source bio and the offset into that bio where
 * the start of data to be cloned is located.
 *
 * On return, bio_src is updated to refer to the bio in the source
 * chain that contains first un-cloned byte, and *offset will
 * contain the offset of that byte within that bio.
 */
static struct bio *bio_chain_clone_range(struct bio **bio_src,
					unsigned int *offset,
					unsigned int len,
					gfp_t gfpmask)
{
	struct bio *bi = *bio_src;
	unsigned int off = *offset;
	struct bio *chain = NULL;
	struct bio **end;

	/* Build up a chain of clone bios up to the limit */

1427
	if (!bi || off >= bi->bi_iter.bi_size || !len)
A
Alex Elder 已提交
1428
		return NULL;		/* Nothing to clone */
1429

A
Alex Elder 已提交
1430 1431 1432 1433 1434
	end = &chain;
	while (len) {
		unsigned int bi_size;
		struct bio *bio;

1435 1436
		if (!bi) {
			rbd_warn(NULL, "bio_chain exhausted with %u left", len);
A
Alex Elder 已提交
1437
			goto out_err;	/* EINVAL; ran out of bio's */
1438
		}
1439
		bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
A
Alex Elder 已提交
1440 1441 1442 1443 1444 1445
		bio = bio_clone_range(bi, off, bi_size, gfpmask);
		if (!bio)
			goto out_err;	/* ENOMEM */

		*end = bio;
		end = &bio->bi_next;
1446

A
Alex Elder 已提交
1447
		off += bi_size;
1448
		if (off == bi->bi_iter.bi_size) {
A
Alex Elder 已提交
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
			bi = bi->bi_next;
			off = 0;
		}
		len -= bi_size;
	}
	*bio_src = bi;
	*offset = off;

	return chain;
out_err:
	bio_chain_put(chain);
1460 1461 1462 1463

	return NULL;
}

1464 1465 1466 1467 1468
/*
 * The default/initial value for all object request flags is 0.  For
 * each flag, once its value is set to 1 it is never reset to 0
 * again.
 */
A
Alex Elder 已提交
1469
static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1470
{
A
Alex Elder 已提交
1471
	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1472 1473
		struct rbd_device *rbd_dev;

A
Alex Elder 已提交
1474
		rbd_dev = obj_request->img_request->rbd_dev;
1475
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1476 1477 1478 1479
			obj_request);
	}
}

A
Alex Elder 已提交
1480
static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1481 1482
{
	smp_mb();
A
Alex Elder 已提交
1483
	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1484 1485
}

A
Alex Elder 已提交
1486
static void obj_request_done_set(struct rbd_obj_request *obj_request)
1487
{
A
Alex Elder 已提交
1488 1489
	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1490

A
Alex Elder 已提交
1491 1492
		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1493
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1494 1495 1496 1497
			obj_request);
	}
}

A
Alex Elder 已提交
1498
static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1499 1500
{
	smp_mb();
A
Alex Elder 已提交
1501
	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1502 1503
}

1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534
/*
 * This sets the KNOWN flag after (possibly) setting the EXISTS
 * flag.  The latter is set based on the "exists" value provided.
 *
 * Note that for our purposes once an object exists it never goes
 * away again.  It's possible that the response from two existence
 * checks are separated by the creation of the target object, and
 * the first ("doesn't exist") response arrives *after* the second
 * ("does exist").  In that case we ignore the second one.
 */
static void obj_request_existence_set(struct rbd_obj_request *obj_request,
				bool exists)
{
	if (exists)
		set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
	set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
	smp_mb();
}

static bool obj_request_known_test(struct rbd_obj_request *obj_request)
{
	smp_mb();
	return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
}

static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
{
	smp_mb();
	return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
}

1535 1536 1537 1538 1539 1540 1541 1542
static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
{
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;

	return obj_request->img_offset <
	    round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
}

A
Alex Elder 已提交
1543 1544
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1545 1546
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1547 1548 1549 1550 1551 1552 1553
	kref_get(&obj_request->kref);
}

static void rbd_obj_request_destroy(struct kref *kref);
static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
{
	rbd_assert(obj_request != NULL);
A
Alex Elder 已提交
1554 1555
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1556 1557 1558
	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1559 1560 1561 1562 1563 1564 1565
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
	     atomic_read(&img_request->kref.refcount));
	kref_get(&img_request->kref);
}

1566 1567
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
A
Alex Elder 已提交
1568 1569 1570 1571
static void rbd_img_request_destroy(struct kref *kref);
static void rbd_img_request_put(struct rbd_img_request *img_request)
{
	rbd_assert(img_request != NULL);
A
Alex Elder 已提交
1572 1573
	dout("%s: img %p (was %d)\n", __func__, img_request,
		atomic_read(&img_request->kref.refcount));
1574 1575 1576 1577
	if (img_request_child_test(img_request))
		kref_put(&img_request->kref, rbd_parent_request_destroy);
	else
		kref_put(&img_request->kref, rbd_img_request_destroy);
A
Alex Elder 已提交
1578 1579 1580 1581 1582
}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1583 1584
	rbd_assert(obj_request->img_request == NULL);

1585
	/* Image request now owns object's original reference */
A
Alex Elder 已提交
1586
	obj_request->img_request = img_request;
1587
	obj_request->which = img_request->obj_request_count;
1588 1589
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
A
Alex Elder 已提交
1590
	rbd_assert(obj_request->which != BAD_WHICH);
1591 1592
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
A
Alex Elder 已提交
1593 1594
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1595 1596 1597 1598 1599 1600
}

static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
	rbd_assert(obj_request->which != BAD_WHICH);
1601

A
Alex Elder 已提交
1602 1603
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1604
	list_del(&obj_request->links);
1605 1606 1607 1608
	rbd_assert(img_request->obj_request_count > 0);
	img_request->obj_request_count--;
	rbd_assert(obj_request->which == img_request->obj_request_count);
	obj_request->which = BAD_WHICH;
1609
	rbd_assert(obj_request_img_data_test(obj_request));
A
Alex Elder 已提交
1610 1611
	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1612
	obj_request->callback = NULL;
A
Alex Elder 已提交
1613 1614 1615 1616 1617 1618
	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1619
	case OBJ_REQUEST_NODATA:
A
Alex Elder 已提交
1620
	case OBJ_REQUEST_BIO:
1621
	case OBJ_REQUEST_PAGES:
A
Alex Elder 已提交
1622 1623 1624 1625 1626 1627
		return true;
	default:
		return false;
	}
}

1628 1629
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

1630
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1631
{
1632 1633
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1634 1635 1636
	dout("%s %p \"%s\" %llu~%llu osd_req %p\n", __func__,
	     obj_request, obj_request->object_name, obj_request->offset,
	     obj_request->length, osd_req);
1637 1638 1639 1640
	if (obj_request_img_data_test(obj_request)) {
		WARN_ON(obj_request->callback != rbd_img_obj_callback);
		rbd_img_request_get(obj_request->img_request);
	}
1641
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
Alex Elder 已提交
1642 1643 1644 1645
}

static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1646

A
Alex Elder 已提交
1647
	dout("%s: img %p\n", __func__, img_request);
1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663

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

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

A
Alex Elder 已提交
1664 1665 1666 1667 1668 1669
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
Alex Elder 已提交
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686
/*
 * The default/initial value for all image request flags is 0.  Each
 * is conditionally set to 1 at image request initialization time
 * and currently never change thereafter.
 */
static void img_request_write_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_WRITE, &img_request->flags);
	smp_mb();
}

static bool img_request_write_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
}

1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701
/*
 * Set the discard flag when the img_request is an discard request
 */
static void img_request_discard_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_DISCARD, &img_request->flags);
	smp_mb();
}

static bool img_request_discard_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_DISCARD, &img_request->flags) != 0;
}

1702 1703 1704 1705 1706 1707
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1708 1709 1710 1711 1712 1713
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1714 1715 1716 1717 1718 1719
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1720 1721 1722 1723 1724 1725
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1726 1727 1728 1729 1730 1731
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1732 1733 1734 1735 1736 1737
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748
static enum obj_operation_type
rbd_img_request_op_type(struct rbd_img_request *img_request)
{
	if (img_request_write_test(img_request))
		return OBJ_OP_WRITE;
	else if (img_request_discard_test(img_request))
		return OBJ_OP_DISCARD;
	else
		return OBJ_OP_READ;
}

1749 1750 1751
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1752 1753 1754
	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1755 1756
	dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
		obj_request, obj_request->img_request, obj_request->result,
A
Alex Elder 已提交
1757
		xferred, length);
1758
	/*
1759 1760 1761 1762 1763 1764
	 * ENOENT means a hole in the image.  We zero-fill the entire
	 * length of the request.  A short read also implies zero-fill
	 * to the end of the request.  An error requires the whole
	 * length of the request to be reported finished with an error
	 * to the block layer.  In each case we update the xferred
	 * count to indicate the whole request was satisfied.
1765
	 */
A
Alex Elder 已提交
1766
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1767
	if (obj_request->result == -ENOENT) {
A
Alex Elder 已提交
1768 1769 1770 1771
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1772
		obj_request->result = 0;
A
Alex Elder 已提交
1773 1774 1775 1776 1777
	} else if (xferred < length && !obj_request->result) {
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, xferred);
		else
			zero_pages(obj_request->pages, xferred, length);
1778
	}
1779
	obj_request->xferred = length;
1780 1781 1782
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1783 1784
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1785 1786
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
A
Alex Elder 已提交
1787 1788
	if (obj_request->callback)
		obj_request->callback(obj_request);
1789 1790
	else
		complete_all(&obj_request->completion);
A
Alex Elder 已提交
1791 1792
}

1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
static void rbd_obj_request_error(struct rbd_obj_request *obj_request, int err)
{
	obj_request->result = err;
	obj_request->xferred = 0;
	/*
	 * kludge - mirror rbd_obj_request_submit() to match a put in
	 * rbd_img_obj_callback()
	 */
	if (obj_request_img_data_test(obj_request)) {
		WARN_ON(obj_request->callback != rbd_img_obj_callback);
		rbd_img_request_get(obj_request->img_request);
	}
	obj_request_done_set(obj_request);
	rbd_obj_request_complete(obj_request);
}

1809
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1810
{
A
Alex Elder 已提交
1811
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1812
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1813 1814 1815 1816 1817
	bool layered = false;

	if (obj_request_img_data_test(obj_request)) {
		img_request = obj_request->img_request;
		layered = img_request && img_request_layered_test(img_request);
A
Alex Elder 已提交
1818
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1819
	}
A
Alex Elder 已提交
1820 1821 1822 1823

	dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
		obj_request, img_request, obj_request->result,
		obj_request->xferred, obj_request->length);
A
Alex Elder 已提交
1824 1825
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1826 1827
		rbd_img_parent_read(obj_request);
	else if (img_request)
1828 1829 1830
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1831 1832
}

1833
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1834
{
1835 1836 1837
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1838 1839
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1840 1841
	 */
	obj_request->xferred = obj_request->length;
1842
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1843 1844
}

1845 1846 1847 1848 1849 1850 1851 1852 1853
static void rbd_osd_discard_callback(struct rbd_obj_request *obj_request)
{
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
	 * There is no such thing as a successful short discard.  Set
	 * it to our originally-requested length.
	 */
	obj_request->xferred = obj_request->length;
1854 1855 1856
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1857 1858 1859
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1860 1861 1862 1863
/*
 * For a simple stat call there's nothing to do.  We'll do more if
 * this is part of a write sequence for a layered image.
 */
1864
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1865
{
A
Alex Elder 已提交
1866
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1867 1868 1869
	obj_request_done_set(obj_request);
}

I
Ilya Dryomov 已提交
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879
static void rbd_osd_call_callback(struct rbd_obj_request *obj_request)
{
	dout("%s: obj %p\n", __func__, obj_request);

	if (obj_request_img_data_test(obj_request))
		rbd_osd_copyup_callback(obj_request);
	else
		obj_request_done_set(obj_request);
}

1880
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
Alex Elder 已提交
1881 1882 1883 1884
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

1885
	dout("%s: osd_req %p\n", __func__, osd_req);
A
Alex Elder 已提交
1886
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1887 1888 1889 1890 1891 1892
	if (obj_request_img_data_test(obj_request)) {
		rbd_assert(obj_request->img_request);
		rbd_assert(obj_request->which != BAD_WHICH);
	} else {
		rbd_assert(obj_request->which == BAD_WHICH);
	}
A
Alex Elder 已提交
1893

1894 1895
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1896

1897 1898
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1899 1900
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1901
	 */
1902
	obj_request->xferred = osd_req->r_ops[0].outdata_len;
A
Alex Elder 已提交
1903
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1904

1905
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1906 1907
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1908
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1909
		break;
1910
	case CEPH_OSD_OP_SETALLOCHINT:
1911 1912
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
			   osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1913
		/* fall through */
A
Alex Elder 已提交
1914
	case CEPH_OSD_OP_WRITE:
1915
	case CEPH_OSD_OP_WRITEFULL:
1916
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1917
		break;
A
Alex Elder 已提交
1918
	case CEPH_OSD_OP_STAT:
1919
		rbd_osd_stat_callback(obj_request);
A
Alex Elder 已提交
1920
		break;
1921 1922 1923 1924 1925
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1926
	case CEPH_OSD_OP_CALL:
I
Ilya Dryomov 已提交
1927 1928
		rbd_osd_call_callback(obj_request);
		break;
A
Alex Elder 已提交
1929
	default:
1930
		rbd_warn(NULL, "%s: unsupported op %hu",
A
Alex Elder 已提交
1931 1932 1933 1934
			obj_request->object_name, (unsigned short) opcode);
		break;
	}

1935
	if (obj_request_done_test(obj_request))
A
Alex Elder 已提交
1936 1937 1938
		rbd_obj_request_complete(obj_request);
}

1939
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1940
{
1941
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1942

1943 1944
	rbd_assert(obj_request_img_data_test(obj_request));
	osd_req->r_snapid = obj_request->img_request->snap_id;
1945 1946 1947 1948 1949 1950
}

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

1951 1952
	osd_req->r_mtime = CURRENT_TIME;
	osd_req->r_data_offset = obj_request->offset;
A
Alex Elder 已提交
1953 1954
}

1955 1956 1957 1958 1959 1960
/*
 * Create an osd request.  A read request has one osd op (read).
 * A write request has either one (watch) or two (hint+write) osd ops.
 * (All rbd data writes are prefixed with an allocation hint op, but
 * technically osd watch is a write request, hence this distinction.)
 */
A
Alex Elder 已提交
1961 1962
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1963
					enum obj_operation_type op_type,
1964
					unsigned int num_ops,
A
Alex Elder 已提交
1965
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1966 1967 1968 1969 1970
{
	struct ceph_snap_context *snapc = NULL;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;

1971 1972
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1973
		struct rbd_img_request *img_request = obj_request->img_request;
1974 1975 1976 1977 1978
		if (op_type == OBJ_OP_WRITE) {
			rbd_assert(img_request_write_test(img_request));
		} else {
			rbd_assert(img_request_discard_test(img_request));
		}
G
Guangliang Zhao 已提交
1979
		snapc = img_request->snapc;
A
Alex Elder 已提交
1980 1981
	}

G
Guangliang Zhao 已提交
1982
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1983 1984

	/* Allocate and initialize the request, for the num_ops ops */
A
Alex Elder 已提交
1985 1986

	osdc = &rbd_dev->rbd_client->client->osdc;
1987
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
1988
					  GFP_NOIO);
A
Alex Elder 已提交
1989
	if (!osd_req)
1990
		goto fail;
A
Alex Elder 已提交
1991

1992
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
A
Alex Elder 已提交
1993
		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
A
Alex Elder 已提交
1994
	else
A
Alex Elder 已提交
1995 1996 1997 1998 1999
		osd_req->r_flags = CEPH_OSD_FLAG_READ;

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

2000
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2001 2002 2003
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
A
Alex Elder 已提交
2004

2005 2006 2007
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

A
Alex Elder 已提交
2008
	return osd_req;
2009 2010 2011 2012

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
A
Alex Elder 已提交
2013 2014
}

2015
/*
2016 2017 2018 2019
 * Create a copyup osd request based on the information in the object
 * request supplied.  A copyup request has two or three osd ops, a
 * copyup method call, potentially a hint op, and a write or truncate
 * or zero op.
2020 2021 2022 2023 2024 2025 2026 2027 2028
 */
static struct ceph_osd_request *
rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	struct ceph_snap_context *snapc;
	struct rbd_device *rbd_dev;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;
2029
	int num_osd_ops = 3;
2030 2031 2032 2033

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
2034 2035
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
2036

2037 2038 2039 2040
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

	/* Allocate and initialize the request, for all the ops */
2041 2042 2043 2044

	snapc = img_request->snapc;
	rbd_dev = img_request->rbd_dev;
	osdc = &rbd_dev->rbd_client->client->osdc;
2045
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2046
						false, GFP_NOIO);
2047
	if (!osd_req)
2048
		goto fail;
2049 2050 2051 2052 2053

	osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
	osd_req->r_callback = rbd_osd_req_callback;
	osd_req->r_priv = obj_request;

2054
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2055 2056 2057
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
2058

2059 2060 2061
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

2062
	return osd_req;
2063 2064 2065 2066

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
2067 2068 2069
}


A
Alex Elder 已提交
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

/* object_name is assumed to be a non-null pointer and NUL-terminated */

static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
						enum obj_request_type type)
{
	struct rbd_obj_request *obj_request;
	size_t size;
	char *name;

	rbd_assert(obj_request_type_valid(type));

	size = strlen(object_name) + 1;
2087
	name = kmalloc(size, GFP_NOIO);
2088
	if (!name)
A
Alex Elder 已提交
2089 2090
		return NULL;

2091
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2092 2093 2094 2095 2096
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2097 2098 2099 2100
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2101
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2102 2103
	kref_init(&obj_request->kref);

2104
	dout("%s %p\n", __func__, obj_request);
A
Alex Elder 已提交
2105 2106 2107 2108 2109 2110 2111 2112 2113
	return obj_request;
}

static void rbd_obj_request_destroy(struct kref *kref)
{
	struct rbd_obj_request *obj_request;

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

A
Alex Elder 已提交
2114 2115
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2116 2117 2118 2119 2120 2121 2122 2123
	rbd_assert(obj_request->img_request == NULL);
	rbd_assert(obj_request->which == BAD_WHICH);

	if (obj_request->osd_req)
		rbd_osd_req_destroy(obj_request->osd_req);

	rbd_assert(obj_request_type_valid(obj_request->type));
	switch (obj_request->type) {
2124 2125
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2126 2127 2128 2129
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2130
	case OBJ_REQUEST_PAGES:
2131 2132 2133
		/* img_data requests don't own their page array */
		if (obj_request->pages &&
		    !obj_request_img_data_test(obj_request))
2134 2135 2136
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2137 2138
	}

2139
	kfree(obj_request->object_name);
2140 2141
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2142 2143
}

A
Alex Elder 已提交
2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154
/* 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;
}

2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176
/*
 * 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
2177
		rbd_warn(rbd_dev, "parent reference underflow");
2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189
}

/*
 * 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)
{
2190
	int counter = 0;
2191 2192 2193 2194

	if (!rbd_dev->parent_spec)
		return false;

2195 2196 2197 2198
	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);
2199 2200

	if (counter < 0)
2201
		rbd_warn(rbd_dev, "parent reference overflow");
2202

2203
	return counter > 0;
2204 2205
}

A
Alex Elder 已提交
2206 2207 2208 2209 2210
/*
 * 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
2211 2212
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2213
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2214
					enum obj_operation_type op_type,
2215
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2216 2217 2218
{
	struct rbd_img_request *img_request;

2219
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2220 2221 2222 2223 2224 2225 2226
	if (!img_request)
		return NULL;

	img_request->rq = NULL;
	img_request->rbd_dev = rbd_dev;
	img_request->offset = offset;
	img_request->length = length;
A
Alex Elder 已提交
2227
	img_request->flags = 0;
2228 2229 2230 2231
	if (op_type == OBJ_OP_DISCARD) {
		img_request_discard_set(img_request);
		img_request->snapc = snapc;
	} else if (op_type == OBJ_OP_WRITE) {
A
Alex Elder 已提交
2232
		img_request_write_set(img_request);
2233
		img_request->snapc = snapc;
A
Alex Elder 已提交
2234
	} else {
A
Alex Elder 已提交
2235
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2236
	}
2237
	if (rbd_dev_parent_get(rbd_dev))
2238
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2239 2240 2241
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2242
	img_request->result = 0;
A
Alex Elder 已提交
2243 2244 2245 2246
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2247
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2248
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2249

A
Alex Elder 已提交
2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260
	return img_request;
}

static void rbd_img_request_destroy(struct kref *kref)
{
	struct rbd_img_request *img_request;
	struct rbd_obj_request *obj_request;
	struct rbd_obj_request *next_obj_request;

	img_request = container_of(kref, struct rbd_img_request, kref);

A
Alex Elder 已提交
2261 2262
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2263 2264
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2265
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2266

2267 2268 2269 2270 2271
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2272 2273
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2274
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2275

2276
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2277 2278
}

2279 2280 2281 2282 2283 2284 2285 2286 2287 2288
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;

2289
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2290
						length, OBJ_OP_READ, NULL);
2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315
	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);
}

2316 2317
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2318
	struct rbd_img_request *img_request;
2319 2320
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2321
	bool more;
2322

2323 2324 2325
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2326 2327 2328 2329 2330
	rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
	xferred = (unsigned int)obj_request->xferred;
	result = obj_request->result;
	if (result) {
		struct rbd_device *rbd_dev = img_request->rbd_dev;
G
Guangliang Zhao 已提交
2331 2332
		enum obj_operation_type op_type;

2333 2334 2335 2336 2337 2338
		if (img_request_discard_test(img_request))
			op_type = OBJ_OP_DISCARD;
		else if (img_request_write_test(img_request))
			op_type = OBJ_OP_WRITE;
		else
			op_type = OBJ_OP_READ;
2339

2340
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2341 2342
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2343
		rbd_warn(rbd_dev, "  result %d xferred %x",
2344 2345 2346
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2347 2348 2349 2350 2351
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2352 2353
	}

A
Alex Elder 已提交
2354 2355 2356 2357 2358
	if (img_request_child_test(img_request)) {
		rbd_assert(img_request->obj_request != NULL);
		more = obj_request->which < img_request->obj_request_count - 1;
	} else {
		rbd_assert(img_request->rq != NULL);
C
Christoph Hellwig 已提交
2359 2360 2361 2362

		more = blk_update_request(img_request->rq, result, xferred);
		if (!more)
			__blk_mq_end_request(img_request->rq, result);
A
Alex Elder 已提交
2363 2364 2365
	}

	return more;
2366 2367
}

2368 2369 2370 2371 2372 2373
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	u32 which = obj_request->which;
	bool more = true;

2374
	rbd_assert(obj_request_img_data_test(obj_request));
2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392
	img_request = obj_request->img_request;

	dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
	rbd_assert(img_request != NULL);
	rbd_assert(img_request->obj_request_count > 0);
	rbd_assert(which != BAD_WHICH);
	rbd_assert(which < img_request->obj_request_count);

	spin_lock_irq(&img_request->completion_lock);
	if (which != img_request->next_completion)
		goto out;

	for_each_obj_request_from(img_request, obj_request) {
		rbd_assert(more);
		rbd_assert(which < img_request->obj_request_count);

		if (!obj_request_done_test(obj_request))
			break;
2393
		more = rbd_img_obj_end_request(obj_request);
2394 2395 2396 2397 2398 2399 2400
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2401
	rbd_img_request_put(img_request);
2402 2403 2404 2405 2406

	if (!more)
		rbd_img_request_complete(img_request);
}

2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425
/*
 * Add individual osd ops to the given ceph_osd_request and prepare
 * them for submission. num_ops is the current number of
 * osd operations already to the object request.
 */
static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
				struct ceph_osd_request *osd_request,
				enum obj_operation_type op_type,
				unsigned int num_ops)
{
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
	u64 object_size = rbd_obj_bytes(&rbd_dev->header);
	u64 offset = obj_request->offset;
	u64 length = obj_request->length;
	u64 img_end;
	u16 opcode;

	if (op_type == OBJ_OP_DISCARD) {
2426 2427 2428
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442
			opcode = CEPH_OSD_OP_DELETE;
		} else if ((offset + length == object_size)) {
			opcode = CEPH_OSD_OP_TRUNCATE;
		} else {
			down_read(&rbd_dev->header_rwsem);
			img_end = rbd_dev->header.image_size;
			up_read(&rbd_dev->header_rwsem);

			if (obj_request->img_offset + length == img_end)
				opcode = CEPH_OSD_OP_TRUNCATE;
			else
				opcode = CEPH_OSD_OP_ZERO;
		}
	} else if (op_type == OBJ_OP_WRITE) {
2443 2444 2445 2446
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2447 2448 2449 2450 2451 2452 2453
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2454
	if (opcode == CEPH_OSD_OP_DELETE)
2455
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2456 2457 2458 2459
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474
	if (obj_request->type == OBJ_REQUEST_BIO)
		osd_req_op_extent_osd_data_bio(osd_request, num_ops,
					obj_request->bio_list, length);
	else if (obj_request->type == OBJ_REQUEST_PAGES)
		osd_req_op_extent_osd_data_pages(osd_request, num_ops,
					obj_request->pages, length,
					offset & ~PAGE_MASK, false, false);

	/* Discards are also writes */
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
		rbd_osd_req_format_write(obj_request);
	else
		rbd_osd_req_format_read(obj_request);
}

2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485
/*
 * 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
2486 2487 2488 2489
{
	struct rbd_device *rbd_dev = img_request->rbd_dev;
	struct rbd_obj_request *obj_request = NULL;
	struct rbd_obj_request *next_obj_request;
J
Jingoo Han 已提交
2490
	struct bio *bio_list = NULL;
2491
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2492
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2493
	enum obj_operation_type op_type;
2494
	u64 img_offset;
A
Alex Elder 已提交
2495 2496
	u64 resid;

2497 2498
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2499

2500
	img_offset = img_request->offset;
A
Alex Elder 已提交
2501
	resid = img_request->length;
A
Alex Elder 已提交
2502
	rbd_assert(resid > 0);
2503
	op_type = rbd_img_request_op_type(img_request);
2504 2505 2506

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2507 2508
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2509
	} else if (type == OBJ_REQUEST_PAGES) {
2510 2511 2512
		pages = data_desc;
	}

A
Alex Elder 已提交
2513
	while (resid) {
2514
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2515
		const char *object_name;
2516 2517
		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
2518

2519
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2520 2521
		if (!object_name)
			goto out_unwind;
2522
		obj_request = rbd_obj_request_create(object_name, type);
2523 2524
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2525 2526
		if (!obj_request)
			goto out_unwind;
2527

2528 2529 2530
		obj_request->offset = offset;
		obj_request->length = length;

2531 2532 2533 2534 2535
		/*
		 * 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
2536

2537 2538 2539 2540 2541 2542 2543 2544 2545
		if (type == OBJ_REQUEST_BIO) {
			unsigned int clone_size;

			rbd_assert(length <= (u64)UINT_MAX);
			clone_size = (unsigned int)length;
			obj_request->bio_list =
					bio_chain_clone_range(&bio_list,
								&bio_offset,
								clone_size,
2546
								GFP_NOIO);
2547
			if (!obj_request->bio_list)
2548
				goto out_unwind;
2549
		} else if (type == OBJ_REQUEST_PAGES) {
2550 2551 2552 2553 2554 2555 2556 2557 2558
			unsigned int page_count;

			obj_request->pages = pages;
			page_count = (u32)calc_pages_for(offset, length);
			obj_request->page_count = page_count;
			if ((offset + length) & ~PAGE_MASK)
				page_count--;	/* more on last page */
			pages += page_count;
		}
A
Alex Elder 已提交
2559

G
Guangliang Zhao 已提交
2560 2561 2562
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2563
		if (!osd_req)
2564
			goto out_unwind;
2565

2566
		obj_request->osd_req = osd_req;
2567
		obj_request->callback = rbd_img_obj_callback;
2568
		obj_request->img_offset = img_offset;
2569

2570
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2571

2572
		img_offset += length;
A
Alex Elder 已提交
2573 2574 2575 2576 2577 2578 2579
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2580
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2581 2582 2583 2584

	return -ENOMEM;
}

2585
static void
I
Ilya Dryomov 已提交
2586
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2587 2588 2589
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2590
	struct page **pages;
2591 2592
	u32 page_count;

I
Ilya Dryomov 已提交
2593 2594
	dout("%s: obj %p\n", __func__, obj_request);

2595 2596
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2597 2598 2599 2600 2601 2602 2603
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);

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

2604 2605
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2606
	obj_request->copyup_pages = NULL;
2607 2608 2609 2610
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2611 2612 2613 2614 2615 2616 2617 2618 2619 2620

	/*
	 * We want the transfer count to reflect the size of the
	 * original write request.  There is no such thing as a
	 * successful short write, so if the request was successful
	 * we can just set it to the originally-requested length.
	 */
	if (!obj_request->result)
		obj_request->xferred = obj_request->length;

I
Ilya Dryomov 已提交
2621
	obj_request_done_set(obj_request);
2622 2623
}

2624 2625 2626 2627
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2628 2629
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2630
	struct page **pages;
2631
	enum obj_operation_type op_type;
2632
	u32 page_count;
2633
	int img_result;
2634
	u64 parent_length;
2635 2636 2637 2638 2639 2640 2641 2642

	rbd_assert(img_request_child_test(img_request));

	/* First get what we need from the image request */

	pages = img_request->copyup_pages;
	rbd_assert(pages != NULL);
	img_request->copyup_pages = NULL;
2643 2644 2645
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2646 2647 2648

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2649
	rbd_assert(obj_request_type_valid(orig_request->type));
2650
	img_result = img_request->result;
2651
	parent_length = img_request->length;
2652
	rbd_assert(img_result || parent_length == img_request->xferred);
2653
	rbd_img_request_put(img_request);
2654

2655 2656
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2657 2658
	rbd_assert(rbd_dev);

2659 2660 2661 2662 2663 2664 2665
	/*
	 * If the overlap has become 0 (most likely because the
	 * image has been flattened) we need to free the pages
	 * and re-submit the original write request.
	 */
	if (!rbd_dev->parent_overlap) {
		ceph_release_page_vector(pages, page_count);
2666 2667
		rbd_obj_request_submit(orig_request);
		return;
2668
	}
2669

2670
	if (img_result)
2671 2672
		goto out_err;

2673 2674
	/*
	 * The original osd request is of no use to use any more.
2675
	 * We need a new one that can hold the three ops in a copyup
2676 2677 2678
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2679
	img_result = -ENOMEM;
2680 2681 2682
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2683
	rbd_osd_req_destroy(orig_request->osd_req);
2684 2685
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2686
	orig_request->copyup_page_count = page_count;
2687

2688
	/* Initialize the copyup op */
2689

2690
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2691
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2692
						false, false);
2693

2694
	/* Add the other op(s) */
2695

2696 2697
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2698 2699 2700

	/* All set, send it off. */

2701 2702
	rbd_obj_request_submit(orig_request);
	return;
2703 2704

out_err:
2705
	ceph_release_page_vector(pages, page_count);
2706
	rbd_obj_request_error(orig_request, img_result);
2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719
}

/*
 * Read from the parent image the range of data that covers the
 * entire target of the given object request.  This is used for
 * satisfying a layered image write request when the target of an
 * object request from the image request does not exist.
 *
 * A page array big enough to hold the returned data is allocated
 * and supplied to rbd_img_request_fill() as the "data descriptor."
 * When the read completes, this page array will be transferred to
 * the original object request for the copyup operation.
 *
2720 2721
 * If an error occurs, it is recorded as the result of the original
 * object request in rbd_img_obj_exists_callback().
2722 2723 2724
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
2725
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739
	struct rbd_img_request *parent_request = NULL;
	u64 img_offset;
	u64 length;
	struct page **pages = NULL;
	u32 page_count;
	int result;

	rbd_assert(rbd_dev->parent != NULL);

	/*
	 * Determine the byte range covered by the object in the
	 * child image to which the original request was to be sent.
	 */
	img_offset = obj_request->img_offset - obj_request->offset;
I
Ilya Dryomov 已提交
2740
	length = rbd_obj_bytes(&rbd_dev->header);
2741

A
Alex Elder 已提交
2742 2743 2744 2745 2746 2747 2748 2749 2750 2751
	/*
	 * There is no defined parent data beyond the parent
	 * overlap, so limit what we read at that boundary if
	 * necessary.
	 */
	if (img_offset + length > rbd_dev->parent_overlap) {
		rbd_assert(img_offset < rbd_dev->parent_overlap);
		length = rbd_dev->parent_overlap - img_offset;
	}

2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764
	/*
	 * Allocate a page array big enough to receive the data read
	 * from the parent.
	 */
	page_count = (u32)calc_pages_for(0, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages)) {
		result = PTR_ERR(pages);
		pages = NULL;
		goto out_err;
	}

	result = -ENOMEM;
2765 2766
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2767 2768 2769 2770 2771 2772
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
2773

2774
	parent_request->copyup_pages = pages;
2775
	parent_request->copyup_page_count = page_count;
2776
	parent_request->callback = rbd_img_obj_parent_read_full_callback;
2777

2778 2779 2780 2781 2782
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2783
	parent_request->copyup_page_count = 0;
2784 2785 2786 2787 2788 2789 2790 2791 2792 2793
	parent_request->obj_request = NULL;
	rbd_obj_request_put(obj_request);
out_err:
	if (pages)
		ceph_release_page_vector(pages, page_count);
	if (parent_request)
		rbd_img_request_put(parent_request);
	return result;
}

2794 2795 2796
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2797
	struct rbd_device *rbd_dev;
2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808
	int result;

	rbd_assert(!obj_request_img_data_test(obj_request));

	/*
	 * All we need from the object request is the original
	 * request and the result of the STAT op.  Grab those, then
	 * we're done with the request.
	 */
	orig_request = obj_request->obj_request;
	obj_request->obj_request = NULL;
2809
	rbd_obj_request_put(orig_request);
2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820
	rbd_assert(orig_request);
	rbd_assert(orig_request->img_request);

	result = obj_request->result;
	obj_request->result = 0;

	dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
		obj_request, orig_request, result,
		obj_request->xferred, obj_request->length);
	rbd_obj_request_put(obj_request);

2821 2822
	/*
	 * If the overlap has become 0 (most likely because the
2823 2824
	 * image has been flattened) we need to re-submit the
	 * original request.
2825 2826 2827
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2828 2829
		rbd_obj_request_submit(orig_request);
		return;
2830
	}
2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841

	/*
	 * Our only purpose here is to determine whether the object
	 * exists, and we don't want to treat the non-existence as
	 * an error.  If something else comes back, transfer the
	 * error to the original request and complete it now.
	 */
	if (!result) {
		obj_request_existence_set(orig_request, true);
	} else if (result == -ENOENT) {
		obj_request_existence_set(orig_request, false);
2842 2843
	} else {
		goto fail_orig_request;
2844 2845 2846 2847 2848 2849
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2850 2851 2852 2853 2854 2855 2856
	result = rbd_img_obj_request_submit(orig_request);
	if (result)
		goto fail_orig_request;

	return;

fail_orig_request:
2857
	rbd_obj_request_error(orig_request, result);
2858 2859 2860 2861
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
2862
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2863
	struct rbd_obj_request *stat_request;
2864
	struct page **pages;
2865 2866 2867 2868
	u32 page_count;
	size_t size;
	int ret;

2869
	stat_request = rbd_obj_request_create(obj_request->object_name,
2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880
					      OBJ_REQUEST_PAGES);
	if (!stat_request)
		return -ENOMEM;

	stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
						   stat_request);
	if (!stat_request->osd_req) {
		ret = -ENOMEM;
		goto fail_stat_request;
	}

2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891
	/*
	 * The response data for a STAT call consists of:
	 *     le64 length;
	 *     struct {
	 *         le32 tv_sec;
	 *         le32 tv_nsec;
	 *     } mtime;
	 */
	size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
	page_count = (u32)calc_pages_for(0, size);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2892 2893 2894 2895
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto fail_stat_request;
	}
2896

2897 2898 2899
	osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
				     false, false);
2900 2901 2902 2903 2904 2905 2906

	rbd_obj_request_get(obj_request);
	stat_request->obj_request = obj_request;
	stat_request->pages = pages;
	stat_request->page_count = page_count;
	stat_request->callback = rbd_img_obj_exists_callback;

2907 2908
	rbd_obj_request_submit(stat_request);
	return 0;
2909

2910 2911
fail_stat_request:
	rbd_obj_request_put(stat_request);
2912 2913 2914
	return ret;
}

2915
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2916
{
2917 2918
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
2919

2920
	/* Reads */
2921 2922
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2923 2924 2925 2926 2927 2928
		return true;

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

2929
	/*
2930 2931
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2932
	 */
2933 2934
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2935

2936 2937 2938 2939 2940 2941 2942 2943
	/*
	 * Entire-object layered writes - we will overwrite whatever
	 * parent data there is anyway.
	 */
	if (!obj_request->offset &&
	    obj_request->length == rbd_obj_bytes(&rbd_dev->header))
		return true;

2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956
	/*
	 * If the object is known to already exist, its parent data has
	 * already been copied.
	 */
	if (obj_request_known_test(obj_request) &&
	    obj_request_exists_test(obj_request))
		return true;

	return false;
}

static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
{
2957 2958 2959
	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request_type_valid(obj_request->type));
	rbd_assert(obj_request->img_request);
2960

2961
	if (img_obj_request_simple(obj_request)) {
2962 2963
		rbd_obj_request_submit(obj_request);
		return 0;
2964 2965 2966
	}

	/*
2967 2968 2969 2970
	 * It's a layered write.  The target object might exist but
	 * we may not know that yet.  If we know it doesn't exist,
	 * start by reading the data for the full target object from
	 * the parent so we can use it for a copyup to the target.
2971
	 */
2972
	if (obj_request_known_test(obj_request))
2973 2974 2975
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
2976 2977 2978 2979

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
2980 2981 2982
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
2983
	struct rbd_obj_request *next_obj_request;
2984
	int ret = 0;
A
Alex Elder 已提交
2985

A
Alex Elder 已提交
2986
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
2987

2988 2989
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2990
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
2991
		if (ret)
2992
			goto out_put_ireq;
A
Alex Elder 已提交
2993 2994
	}

2995 2996 2997
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
2998
}
A
Alex Elder 已提交
2999 3000 3001 3002

static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
A
Alex Elder 已提交
3003 3004
	struct rbd_device *rbd_dev;
	u64 obj_end;
3005 3006
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
3007 3008 3009

	rbd_assert(img_request_child_test(img_request));

3010 3011
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
3012
	obj_request = img_request->obj_request;
3013 3014 3015 3016 3017 3018 3019 3020 3021
	img_xferred = img_request->xferred;
	img_result = img_request->result;
	rbd_img_request_put(img_request);

	/*
	 * If the overlap has become 0 (most likely because the
	 * image has been flattened) we need to re-submit the
	 * original request.
	 */
A
Alex Elder 已提交
3022 3023
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
3024 3025
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
3026 3027
		rbd_obj_request_submit(obj_request);
		return;
3028
	}
A
Alex Elder 已提交
3029

3030
	obj_request->result = img_result;
A
Alex Elder 已提交
3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048
	if (obj_request->result)
		goto out;

	/*
	 * We need to zero anything beyond the parent overlap
	 * boundary.  Since rbd_img_obj_request_read_callback()
	 * will zero anything beyond the end of a short read, an
	 * easy way to do this is to pretend the data from the
	 * parent came up short--ending at the overlap boundary.
	 */
	rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
	obj_end = obj_request->img_offset + obj_request->length;
	if (obj_end > rbd_dev->parent_overlap) {
		u64 xferred = 0;

		if (obj_request->img_offset < rbd_dev->parent_overlap)
			xferred = rbd_dev->parent_overlap -
					obj_request->img_offset;
A
Alex Elder 已提交
3049

3050
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
3051
	} else {
3052
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
3053 3054
	}
out:
A
Alex Elder 已提交
3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066
	rbd_img_obj_request_read_callback(obj_request);
	rbd_obj_request_complete(obj_request);
}

static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	int result;

	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request->img_request != NULL);
	rbd_assert(obj_request->result == (s32) -ENOENT);
3067
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3068 3069

	/* rbd_read_finish(obj_request, obj_request->length); */
3070
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
3071
						obj_request->img_offset,
3072
						obj_request->length);
A
Alex Elder 已提交
3073 3074 3075 3076
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

3077 3078 3079 3080 3081 3082
	if (obj_request->type == OBJ_REQUEST_BIO)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
						obj_request->bio_list);
	else
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
						obj_request->pages);
A
Alex Elder 已提交
3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098
	if (result)
		goto out_err;

	img_request->callback = rbd_img_parent_read_callback;
	result = rbd_img_request_submit(img_request);
	if (result)
		goto out_err;

	return;
out_err:
	if (img_request)
		rbd_img_request_put(img_request);
	obj_request->result = result;
	obj_request->xferred = 0;
	obj_request_done_set(obj_request);
}
A
Alex Elder 已提交
3099

3100
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
3101

3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141
static bool rbd_cid_equal(const struct rbd_client_id *lhs,
			  const struct rbd_client_id *rhs)
{
	return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
}

static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
{
	struct rbd_client_id cid;

	mutex_lock(&rbd_dev->watch_mutex);
	cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
	cid.handle = rbd_dev->watch_cookie;
	mutex_unlock(&rbd_dev->watch_mutex);
	return cid;
}

/*
 * lock_rwsem must be held for write
 */
static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
			      const struct rbd_client_id *cid)
{
	dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
	     rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
	     cid->gid, cid->handle);
	rbd_dev->owner_cid = *cid; /* struct */
}

static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
{
	mutex_lock(&rbd_dev->watch_mutex);
	sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
	mutex_unlock(&rbd_dev->watch_mutex);
}

/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3142
{
3143
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3144 3145
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
	char cookie[32];
3146
	int ret;
A
Alex Elder 已提交
3147

3148
	WARN_ON(__rbd_is_lock_owner(rbd_dev));
3149

3150 3151 3152 3153
	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);
3154
	if (ret)
3155
		return ret;
A
Alex Elder 已提交
3156

3157 3158 3159 3160
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
	rbd_set_owner_cid(rbd_dev, &cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
	return 0;
A
Alex Elder 已提交
3161 3162
}

3163 3164 3165 3166
/*
 * lock_rwsem must be held for write
 */
static int rbd_unlock(struct rbd_device *rbd_dev)
3167
{
3168
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3169
	char cookie[32];
3170 3171
	int ret;

3172
	WARN_ON(!__rbd_is_lock_owner(rbd_dev));
3173

3174
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3175

3176 3177 3178 3179 3180 3181
	format_lock_cookie(rbd_dev, cookie);
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
			      RBD_LOCK_NAME, cookie);
	if (ret && ret != -ENOENT) {
		rbd_warn(rbd_dev, "cls_unlock failed: %d", ret);
		return ret;
3182 3183
	}

3184 3185 3186
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
	return 0;
3187 3188
}

3189 3190 3191 3192
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)
3193 3194
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3195 3196 3197 3198
	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;
3199

3200
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3201

3202 3203 3204 3205 3206
	/* 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);
3207

3208 3209 3210
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3211 3212
}

3213 3214
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
3215
{
3216 3217
	struct page **reply_pages;
	size_t reply_len;
3218

3219 3220 3221
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
3222

3223 3224 3225 3226
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
3227

3228
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3229 3230
}

3231
static void rbd_notify_released_lock(struct work_struct *work)
3232
{
3233 3234
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
3235

3236
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3237 3238
}

3239
static int rbd_request_lock(struct rbd_device *rbd_dev)
3240
{
3241 3242 3243
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
3244 3245
	int ret;

3246
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3247

3248 3249 3250 3251
	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);
3252
		goto out;
3253
	}
3254

3255 3256 3257 3258
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
3259

3260 3261 3262 3263
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
3264

3265 3266
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
3267

3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543
			ceph_decode_32_safe(&p, end, len, e_inval);
			if (!len)
				continue;

			if (lock_owner_responded) {
				rbd_warn(rbd_dev,
					 "duplicate lock owners detected");
				ret = -EIO;
				goto out;
			}

			lock_owner_responded = true;
			ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
						  &struct_v, &len);
			if (ret) {
				rbd_warn(rbd_dev,
					 "failed to decode ResponseMessage: %d",
					 ret);
				goto e_inval;
			}

			ret = ceph_decode_32(&p);
		}
	}

	if (!lock_owner_responded) {
		rbd_warn(rbd_dev, "no lock owners detected");
		ret = -ETIMEDOUT;
	}

out:
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
	return ret;

e_inval:
	ret = -EINVAL;
	goto out;
}

static void wake_requests(struct rbd_device *rbd_dev, bool wake_all)
{
	dout("%s rbd_dev %p wake_all %d\n", __func__, rbd_dev, wake_all);

	cancel_delayed_work(&rbd_dev->lock_dwork);
	if (wake_all)
		wake_up_all(&rbd_dev->lock_waitq);
	else
		wake_up(&rbd_dev->lock_waitq);
}

static int get_lock_owner_info(struct rbd_device *rbd_dev,
			       struct ceph_locker **lockers, u32 *num_lockers)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	u8 lock_type;
	char *lock_tag;
	int ret;

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

	ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
				 &rbd_dev->header_oloc, RBD_LOCK_NAME,
				 &lock_type, &lock_tag, lockers, num_lockers);
	if (ret)
		return ret;

	if (*num_lockers == 0) {
		dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
		goto out;
	}

	if (strcmp(lock_tag, RBD_LOCK_TAG)) {
		rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
			 lock_tag);
		ret = -EBUSY;
		goto out;
	}

	if (lock_type == CEPH_CLS_LOCK_SHARED) {
		rbd_warn(rbd_dev, "shared lock type detected");
		ret = -EBUSY;
		goto out;
	}

	if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
		    strlen(RBD_LOCK_COOKIE_PREFIX))) {
		rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
			 (*lockers)[0].id.cookie);
		ret = -EBUSY;
		goto out;
	}

out:
	kfree(lock_tag);
	return ret;
}

static int find_watcher(struct rbd_device *rbd_dev,
			const struct ceph_locker *locker)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_watch_item *watchers;
	u32 num_watchers;
	u64 cookie;
	int i;
	int ret;

	ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
				      &rbd_dev->header_oloc, &watchers,
				      &num_watchers);
	if (ret)
		return ret;

	sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
	for (i = 0; i < num_watchers; i++) {
		if (!memcmp(&watchers[i].addr, &locker->info.addr,
			    sizeof(locker->info.addr)) &&
		    watchers[i].cookie == cookie) {
			struct rbd_client_id cid = {
				.gid = le64_to_cpu(watchers[i].name.num),
				.handle = cookie,
			};

			dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
			     rbd_dev, cid.gid, cid.handle);
			rbd_set_owner_cid(rbd_dev, &cid);
			ret = 1;
			goto out;
		}
	}

	dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
	ret = 0;
out:
	kfree(watchers);
	return ret;
}

/*
 * lock_rwsem must be held for write
 */
static int rbd_try_lock(struct rbd_device *rbd_dev)
{
	struct ceph_client *client = rbd_dev->rbd_client->client;
	struct ceph_locker *lockers;
	u32 num_lockers;
	int ret;

	for (;;) {
		ret = rbd_lock(rbd_dev);
		if (ret != -EBUSY)
			return ret;

		/* determine if the current lock holder is still alive */
		ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers);
		if (ret)
			return ret;

		if (num_lockers == 0)
			goto again;

		ret = find_watcher(rbd_dev, lockers);
		if (ret) {
			if (ret > 0)
				ret = 0; /* have to request lock */
			goto out;
		}

		rbd_warn(rbd_dev, "%s%llu seems dead, breaking lock",
			 ENTITY_NAME(lockers[0].id.name));

		ret = ceph_monc_blacklist_add(&client->monc,
					      &lockers[0].info.addr);
		if (ret) {
			rbd_warn(rbd_dev, "blacklist of %s%llu failed: %d",
				 ENTITY_NAME(lockers[0].id.name), ret);
			goto out;
		}

		ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
					  &rbd_dev->header_oloc, RBD_LOCK_NAME,
					  lockers[0].id.cookie,
					  &lockers[0].id.name);
		if (ret && ret != -ENOENT)
			goto out;

again:
		ceph_free_lockers(lockers, num_lockers);
	}

out:
	ceph_free_lockers(lockers, num_lockers);
	return ret;
}

/*
 * ret is set only if lock_state is RBD_LOCK_STATE_UNLOCKED
 */
static enum rbd_lock_state rbd_try_acquire_lock(struct rbd_device *rbd_dev,
						int *pret)
{
	enum rbd_lock_state lock_state;

	down_read(&rbd_dev->lock_rwsem);
	dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (__rbd_is_lock_owner(rbd_dev)) {
		lock_state = rbd_dev->lock_state;
		up_read(&rbd_dev->lock_rwsem);
		return lock_state;
	}

	up_read(&rbd_dev->lock_rwsem);
	down_write(&rbd_dev->lock_rwsem);
	dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (!__rbd_is_lock_owner(rbd_dev)) {
		*pret = rbd_try_lock(rbd_dev);
		if (*pret)
			rbd_warn(rbd_dev, "failed to acquire lock: %d", *pret);
	}

	lock_state = rbd_dev->lock_state;
	up_write(&rbd_dev->lock_rwsem);
	return lock_state;
}

static void rbd_acquire_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
					    struct rbd_device, lock_dwork);
	enum rbd_lock_state lock_state;
	int ret;

	dout("%s rbd_dev %p\n", __func__, rbd_dev);
again:
	lock_state = rbd_try_acquire_lock(rbd_dev, &ret);
	if (lock_state != RBD_LOCK_STATE_UNLOCKED || ret == -EBLACKLISTED) {
		if (lock_state == RBD_LOCK_STATE_LOCKED)
			wake_requests(rbd_dev, true);
		dout("%s rbd_dev %p lock_state %d ret %d - done\n", __func__,
		     rbd_dev, lock_state, ret);
		return;
	}

	ret = rbd_request_lock(rbd_dev);
	if (ret == -ETIMEDOUT) {
		goto again; /* treat this as a dead client */
	} else if (ret < 0) {
		rbd_warn(rbd_dev, "error requesting lock: %d", ret);
		mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
				 RBD_RETRY_DELAY);
	} else {
		/*
		 * lock owner acked, but resend if we don't see them
		 * release the lock
		 */
		dout("%s rbd_dev %p requeueing lock_dwork\n", __func__,
		     rbd_dev);
		mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
		    msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
	}
}

/*
 * lock_rwsem must be held for write
 */
static bool rbd_release_lock(struct rbd_device *rbd_dev)
{
	dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
		return false;

	rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
	downgrade_write(&rbd_dev->lock_rwsem);
3544
	/*
3545
	 * Ensure that all in-flight IO is flushed.
3546
	 *
3547 3548
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3549
	 */
3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696
	ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc);
	up_read(&rbd_dev->lock_rwsem);

	down_write(&rbd_dev->lock_rwsem);
	dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
	     rbd_dev->lock_state);
	if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
		return false;

	if (!rbd_unlock(rbd_dev))
		/*
		 * Give others a chance to grab the lock - we would re-acquire
		 * almost immediately if we got new IO during ceph_osdc_sync()
		 * otherwise.  We need to ack our own notifications, so this
		 * lock_dwork will be requeued from rbd_wait_state_locked()
		 * after wake_requests() in rbd_handle_released_lock().
		 */
		cancel_delayed_work(&rbd_dev->lock_dwork);

	return true;
}

static void rbd_release_lock_work(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  unlock_work);

	down_write(&rbd_dev->lock_rwsem);
	rbd_release_lock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
}

static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
				     void **p)
{
	struct rbd_client_id cid = { 0 };

	if (struct_v >= 2) {
		cid.gid = ceph_decode_64(p);
		cid.handle = ceph_decode_64(p);
	}

	dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
	     cid.handle);
	if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
		down_write(&rbd_dev->lock_rwsem);
		if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
			/*
			 * we already know that the remote client is
			 * the owner
			 */
			up_write(&rbd_dev->lock_rwsem);
			return;
		}

		rbd_set_owner_cid(rbd_dev, &cid);
		downgrade_write(&rbd_dev->lock_rwsem);
	} else {
		down_read(&rbd_dev->lock_rwsem);
	}

	if (!__rbd_is_lock_owner(rbd_dev))
		wake_requests(rbd_dev, false);
	up_read(&rbd_dev->lock_rwsem);
}

static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
				     void **p)
{
	struct rbd_client_id cid = { 0 };

	if (struct_v >= 2) {
		cid.gid = ceph_decode_64(p);
		cid.handle = ceph_decode_64(p);
	}

	dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
	     cid.handle);
	if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
		down_write(&rbd_dev->lock_rwsem);
		if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
			dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n",
			     __func__, rbd_dev, cid.gid, cid.handle,
			     rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
			up_write(&rbd_dev->lock_rwsem);
			return;
		}

		rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
		downgrade_write(&rbd_dev->lock_rwsem);
	} else {
		down_read(&rbd_dev->lock_rwsem);
	}

	if (!__rbd_is_lock_owner(rbd_dev))
		wake_requests(rbd_dev, false);
	up_read(&rbd_dev->lock_rwsem);
}

static bool rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
				    void **p)
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
	bool need_to_send;

	if (struct_v >= 2) {
		cid.gid = ceph_decode_64(p);
		cid.handle = ceph_decode_64(p);
	}

	dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
	     cid.handle);
	if (rbd_cid_equal(&cid, &my_cid))
		return false;

	down_read(&rbd_dev->lock_rwsem);
	need_to_send = __rbd_is_lock_owner(rbd_dev);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
		if (!rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid)) {
			dout("%s rbd_dev %p queueing unlock_work\n", __func__,
			     rbd_dev);
			queue_work(rbd_dev->task_wq, &rbd_dev->unlock_work);
		}
	}
	up_read(&rbd_dev->lock_rwsem);
	return need_to_send;
}

static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
				     u64 notify_id, u64 cookie, s32 *result)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN;
	char buf[buf_size];
	int ret;

	if (result) {
		void *p = buf;

		/* encode ResponseMessage */
		ceph_start_encoding(&p, 1, 1,
				    buf_size - CEPH_ENCODING_START_BLK_LEN);
		ceph_encode_32(&p, *result);
	} else {
		buf_size = 0;
	}
A
Alex Elder 已提交
3697

3698 3699
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3700
				   buf, buf_size);
3701
	if (ret)
3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724
		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;
3725
	u8 struct_v = 0;
3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783
	u32 len;
	u32 notify_op;
	int ret;

	dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
	     __func__, rbd_dev, cookie, notify_id, data_len);
	if (data_len) {
		ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
					  &struct_v, &len);
		if (ret) {
			rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
				 ret);
			return;
		}

		notify_op = ceph_decode_32(&p);
	} else {
		/* legacy notification for header updates */
		notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
		len = 0;
	}

	dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
	switch (notify_op) {
	case RBD_NOTIFY_OP_ACQUIRED_LOCK:
		rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
		rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	case RBD_NOTIFY_OP_RELEASED_LOCK:
		rbd_handle_released_lock(rbd_dev, struct_v, &p);
		rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	case RBD_NOTIFY_OP_REQUEST_LOCK:
		if (rbd_handle_request_lock(rbd_dev, struct_v, &p))
			/*
			 * send ResponseMessage(0) back so the client
			 * can detect a missing owner
			 */
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
						      cookie, 0);
		else
			rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	case RBD_NOTIFY_OP_HEADER_UPDATE:
		ret = rbd_dev_refresh(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "refresh failed: %d", ret);

		rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	default:
		if (rbd_is_lock_owner(rbd_dev))
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
						      cookie, -EOPNOTSUPP);
		else
			rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
		break;
	}
A
Alex Elder 已提交
3784 3785
}

3786 3787
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3788
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3789
{
3790
	struct rbd_device *rbd_dev = arg;
3791

3792
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3793

3794 3795 3796 3797
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3798 3799 3800 3801
	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;
3802

3803
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3804
	}
3805
	mutex_unlock(&rbd_dev->watch_mutex);
3806 3807
}

3808
/*
3809
 * watch_mutex must be locked
3810
 */
3811
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3812 3813
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3814
	struct ceph_osd_linger_request *handle;
3815

3816
	rbd_assert(!rbd_dev->watch_handle);
3817
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3818

3819 3820 3821 3822 3823
	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);
3824

3825
	rbd_dev->watch_handle = handle;
3826 3827 3828
	return 0;
}

3829 3830 3831 3832
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3833
{
3834 3835
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3836

3837 3838
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3839

3840 3841 3842
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3843

3844
	rbd_dev->watch_handle = NULL;
3845 3846
}

3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865
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)
3866
{
3867 3868 3869
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3870 3871 3872 3873
	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);
3874 3875 3876 3877
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3878
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3879 3880 3881 3882 3883 3884 3885
	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
3886 3887

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3888 3889
}

3890 3891 3892 3893
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);
3894
	bool was_lock_owner = false;
3895
	bool need_to_wake = false;
3896 3897 3898 3899
	int ret;

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

3900 3901 3902 3903
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		was_lock_owner = rbd_release_lock(rbd_dev);

3904
	mutex_lock(&rbd_dev->watch_mutex);
3905 3906 3907 3908
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
	}
3909 3910 3911 3912

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3913
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3914 3915 3916
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
			need_to_wake = true;
		} else {
3917 3918 3919
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3920 3921 3922
		}
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
3923 3924
	}

3925
	need_to_wake = true;
3926 3927 3928 3929 3930 3931 3932 3933
	rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
	rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
	mutex_unlock(&rbd_dev->watch_mutex);

	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);

3934 3935 3936 3937 3938 3939 3940
	if (was_lock_owner) {
		ret = rbd_try_lock(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "reregisteration lock failed: %d",
				 ret);
	}

3941
out:
3942
	up_write(&rbd_dev->lock_rwsem);
3943 3944
	if (need_to_wake)
		wake_requests(rbd_dev, true);
3945 3946
}

3947
/*
3948 3949
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3950 3951
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3952 3953
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3954
			     const char *method_name,
3955
			     const void *outbound,
3956
			     size_t outbound_size,
3957
			     void *inbound,
3958
			     size_t inbound_size)
3959
{
3960 3961 3962
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3963 3964 3965
	int ret;

	/*
3966 3967 3968 3969 3970
	 * 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.
3971
	 */
3972 3973 3974
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3975

3976 3977 3978
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3979

3980
		memcpy(page_address(req_page), outbound, outbound_size);
3981
	}
A
Alex Elder 已提交
3982

3983 3984 3985 3986 3987 3988
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3989

3990 3991 3992 3993 3994 3995 3996
	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;
	}
3997

3998 3999 4000
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
4001 4002 4003
	return ret;
}

4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022
/*
 * 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);
4023 4024 4025
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

4026 4027 4028
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
4029
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
4030
{
C
Christoph Hellwig 已提交
4031 4032
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
4033
	struct rbd_img_request *img_request;
4034
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
4035 4036
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
4037
	enum obj_operation_type op_type;
4038
	u64 mapping_size;
I
Ilya Dryomov 已提交
4039
	bool must_be_locked;
A
Alex Elder 已提交
4040 4041
	int result;

C
Christoph Hellwig 已提交
4042 4043 4044 4045 4046 4047 4048
	if (rq->cmd_type != REQ_TYPE_FS) {
		dout("%s: non-fs request type %d\n", __func__,
			(int) rq->cmd_type);
		result = -EIO;
		goto err;
	}

M
Mike Christie 已提交
4049
	if (req_op(rq) == REQ_OP_DISCARD)
4050
		op_type = OBJ_OP_DISCARD;
M
Mike Christie 已提交
4051
	else if (req_op(rq) == REQ_OP_WRITE)
G
Guangliang Zhao 已提交
4052 4053 4054 4055
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
4056
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4057

I
Ilya Dryomov 已提交
4058 4059 4060 4061 4062
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4063

G
Guangliang Zhao 已提交
4064
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
4065

G
Guangliang Zhao 已提交
4066
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
4067 4068 4069
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
4070
		}
I
Ilya Dryomov 已提交
4071 4072
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
4073

I
Ilya Dryomov 已提交
4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085
	/*
	 * 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
4086

I
Ilya Dryomov 已提交
4087 4088 4089 4090 4091 4092
	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
4093

C
Christoph Hellwig 已提交
4094 4095
	blk_mq_start_request(rq);

4096 4097
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4098
	if (op_type != OBJ_OP_READ) {
4099 4100
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
4101
		must_be_locked = rbd_is_lock_supported(rbd_dev);
I
Ilya Dryomov 已提交
4102 4103 4104
	} else {
		must_be_locked = rbd_dev->opts->lock_on_read &&
					rbd_is_lock_supported(rbd_dev);
4105 4106 4107 4108
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4109
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4110
			 length, mapping_size);
I
Ilya Dryomov 已提交
4111 4112 4113
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4114

4115 4116
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
4117 4118
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
4119
			rbd_wait_state_locked(rbd_dev);
4120 4121 4122 4123 4124 4125 4126

		WARN_ON((rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) ^
			!test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
4127 4128
	}

G
Guangliang Zhao 已提交
4129
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4130
					     snapc);
I
Ilya Dryomov 已提交
4131 4132
	if (!img_request) {
		result = -ENOMEM;
4133
		goto err_unlock;
I
Ilya Dryomov 已提交
4134 4135
	}
	img_request->rq = rq;
4136
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4137

4138 4139 4140 4141 4142 4143
	if (op_type == OBJ_OP_DISCARD)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
					      NULL);
	else
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
					      rq->bio);
I
Ilya Dryomov 已提交
4144 4145
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4146

I
Ilya Dryomov 已提交
4147 4148 4149
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4150

4151 4152
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4153
	return;
A
Alex Elder 已提交
4154

I
Ilya Dryomov 已提交
4155 4156
err_img_request:
	rbd_img_request_put(img_request);
4157 4158 4159
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4160 4161 4162
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4163
			 obj_op_name(op_type), length, offset, result);
4164
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4165 4166
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
4167
}
A
Alex Elder 已提交
4168

C
Christoph Hellwig 已提交
4169 4170
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4171
{
C
Christoph Hellwig 已提交
4172 4173
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4174

C
Christoph Hellwig 已提交
4175 4176
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
4177 4178
}

4179 4180 4181 4182 4183 4184 4185
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

4186 4187
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
4188
		del_gendisk(disk);
4189 4190
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
4191
		blk_mq_free_tag_set(&rbd_dev->tag_set);
4192
	}
4193 4194 4195
	put_disk(disk);
}

4196
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4197 4198 4199
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
4200 4201

{
4202 4203 4204 4205
	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);
4206 4207
	int ret;

4208 4209 4210
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
4211

4212 4213 4214
	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
4215

4216
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
4217
	if (ret)
4218
		goto out_req;
4219

4220 4221 4222 4223 4224
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
4225

4226 4227 4228 4229 4230 4231 4232 4233
	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);
4234

4235 4236
out_req:
	ceph_osdc_put_request(req);
4237 4238 4239
	return ret;
}

4240
/*
A
Alex Elder 已提交
4241 4242 4243
 * 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.
4244
 */
4245
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4246
{
4247
	struct rbd_image_header_ondisk *ondisk = NULL;
4248
	u32 snap_count = 0;
4249 4250 4251
	u64 names_size = 0;
	u32 want_count;
	int ret;
4252

A
Alex Elder 已提交
4253
	/*
4254 4255 4256 4257 4258
	 * 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
4259
	 */
4260 4261 4262 4263 4264 4265 4266 4267 4268 4269
	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
4270
			return -ENOMEM;
4271

4272 4273
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
4274
		if (ret < 0)
A
Alex Elder 已提交
4275
			goto out;
A
Alex Elder 已提交
4276
		if ((size_t)ret < size) {
4277
			ret = -ENXIO;
A
Alex Elder 已提交
4278 4279
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4280
			goto out;
4281 4282 4283
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4284
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4285
			goto out;
4286
		}
4287

4288 4289 4290 4291
		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
4292

A
Alex Elder 已提交
4293 4294
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4295 4296 4297
	kfree(ondisk);

	return ret;
4298 4299
}

4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318
/*
 * 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);
}

4319 4320 4321 4322 4323
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4324 4325 4326
	 * 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.
4327
	 */
I
Ilya Dryomov 已提交
4328 4329
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4330 4331 4332 4333 4334 4335 4336
		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
4337
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4338
{
4339
	u64 mapping_size;
A
Alex Elder 已提交
4340 4341
	int ret;

4342
	down_write(&rbd_dev->header_rwsem);
4343
	mapping_size = rbd_dev->mapping.size;
4344 4345

	ret = rbd_dev_header_info(rbd_dev);
4346
	if (ret)
4347
		goto out;
4348

4349 4350 4351 4352 4353 4354 4355
	/*
	 * 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)
4356
			goto out;
4357 4358
	}

4359
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4360
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4361 4362 4363 4364
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4365

4366
out:
4367
	up_write(&rbd_dev->header_rwsem);
4368
	if (!ret && mapping_size != rbd_dev->mapping.size)
4369
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4370

4371
	return ret;
A
Alex Elder 已提交
4372 4373
}

C
Christoph Hellwig 已提交
4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388
static int rbd_init_request(void *data, struct request *rq,
		unsigned int hctx_idx, unsigned int request_idx,
		unsigned int numa_node)
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

static struct blk_mq_ops rbd_mq_ops = {
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

4389 4390 4391 4392
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4393
	u64 segment_size;
C
Christoph Hellwig 已提交
4394
	int err;
4395 4396

	/* create gendisk info */
4397 4398 4399
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4400
	if (!disk)
A
Alex Elder 已提交
4401
		return -ENOMEM;
4402

A
Alex Elder 已提交
4403
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4404
		 rbd_dev->dev_id);
4405
	disk->major = rbd_dev->major;
4406
	disk->first_minor = rbd_dev->minor;
4407 4408
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4409 4410 4411
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4412 4413
	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
4414
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4415
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4416
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4417 4418 4419 4420 4421
	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)
4422
		goto out_disk;
4423

C
Christoph Hellwig 已提交
4424 4425 4426 4427 4428 4429
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4430 4431
	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
4432

4433
	/* set io sizes to object size */
A
Alex Elder 已提交
4434 4435
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4436
	q->limits.max_sectors = queue_max_hw_sectors(q);
I
Ilya Dryomov 已提交
4437
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
4438 4439 4440
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4441

4442 4443 4444 4445
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
4446
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4447
	q->limits.discard_zeroes_data = 1;
4448

4449 4450 4451
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
		q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

4452 4453 4454 4455 4456 4457 4458
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4459 4460
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4461 4462
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4463
	return err;
4464 4465
}

4466 4467 4468 4469
/*
  sysfs
*/

A
Alex Elder 已提交
4470 4471 4472 4473 4474
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4475 4476 4477
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4478
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4479

A
Alex Elder 已提交
4480 4481
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4482 4483
}

A
Alex Elder 已提交
4484 4485 4486 4487 4488 4489 4490 4491 4492 4493
/*
 * 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
4494
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4495 4496
}

4497 4498 4499
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4500
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4501

A
Alex Elder 已提交
4502 4503 4504 4505
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4506 4507 4508 4509 4510 4511
}

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
4512

4513
	return sprintf(buf, "%d\n", rbd_dev->minor);
4514 4515
}

4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526
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));
}

4527 4528
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4529
{
A
Alex Elder 已提交
4530
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4531

4532
	return sprintf(buf, "client%lld\n",
4533
		       ceph_client_gid(rbd_dev->rbd_client->client));
4534 4535
}

4536 4537 4538 4539 4540 4541 4542 4543
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);
}

4544 4545 4546 4547 4548 4549
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);
4550 4551
}

4552 4553
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4554
{
A
Alex Elder 已提交
4555
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4556

4557
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4558 4559
}

4560 4561 4562 4563 4564
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);

4565
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4566
			(unsigned long long) rbd_dev->spec->pool_id);
4567 4568
}

4569 4570 4571
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4572
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4573

A
Alex Elder 已提交
4574 4575 4576 4577
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4578 4579
}

A
Alex Elder 已提交
4580 4581 4582 4583 4584
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);

4585
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4586 4587
}

A
Alex Elder 已提交
4588 4589 4590 4591
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4592 4593 4594 4595
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4596
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4597

4598
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4599 4600
}

4601 4602 4603 4604 4605 4606 4607 4608
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);
}

4609
/*
4610 4611 4612
 * 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)".
4613 4614
 */
static ssize_t rbd_parent_show(struct device *dev,
4615 4616
			       struct device_attribute *attr,
			       char *buf)
4617 4618
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4619
	ssize_t count = 0;
4620

4621
	if (!rbd_dev->parent)
4622 4623
		return sprintf(buf, "(no parent image)\n");

4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639
	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;
4640 4641
}

4642 4643 4644 4645 4646
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
4647
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4648
	int ret;
4649

A
Alex Elder 已提交
4650
	ret = rbd_dev_refresh(rbd_dev);
4651
	if (ret)
4652
		return ret;
4653

4654
	return size;
4655
}
4656

4657
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4658
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4659
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4660
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4661
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4662
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4663
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4664
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4665
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4666
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4667
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4668
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4669 4670
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4671
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4672
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4673 4674 4675

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4676
	&dev_attr_features.attr,
4677
	&dev_attr_major.attr,
4678
	&dev_attr_minor.attr,
4679
	&dev_attr_client_addr.attr,
4680
	&dev_attr_client_id.attr,
4681
	&dev_attr_cluster_fsid.attr,
4682
	&dev_attr_config_info.attr,
4683
	&dev_attr_pool.attr,
4684
	&dev_attr_pool_id.attr,
4685
	&dev_attr_name.attr,
A
Alex Elder 已提交
4686
	&dev_attr_image_id.attr,
4687
	&dev_attr_current_snap.attr,
4688
	&dev_attr_snap_id.attr,
4689
	&dev_attr_parent.attr,
4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702
	&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
};

4703
static void rbd_dev_release(struct device *dev);
4704 4705 4706 4707

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4708
	.release	= rbd_dev_release,
4709 4710
};

4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731
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;
4732 4733 4734

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750
	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);
}

4751
static void rbd_dev_free(struct rbd_device *rbd_dev)
4752
{
4753
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4754
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4755

4756
	ceph_oid_destroy(&rbd_dev->header_oid);
4757
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4758
	kfree(rbd_dev->config_info);
4759

4760 4761 4762 4763
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776
}

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);
4777 4778 4779 4780 4781 4782 4783 4784 4785 4786

	/*
	 * 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);
}

4787 4788
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4789 4790 4791
{
	struct rbd_device *rbd_dev;

4792
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4793 4794 4795 4796 4797 4798 4799
	if (!rbd_dev)
		return NULL;

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

4800
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4801
	ceph_oid_init(&rbd_dev->header_oid);
4802
	rbd_dev->header_oloc.pool = spec->pool_id;
4803

4804 4805 4806 4807
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4808 4809 4810 4811 4812 4813 4814 4815
	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);

4816 4817 4818 4819 4820
	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);

4821
	rbd_dev->rbd_client = rbdc;
4822
	rbd_dev->spec = spec;
4823

4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853
	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;
4854

4855 4856
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4857

4858
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4859
	return rbd_dev;
4860 4861 4862 4863 4864 4865

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4866 4867 4868 4869
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4870 4871
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4872 4873
}

4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888
/*
 * 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 };

4889 4890 4891 4892
	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));
4893
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4894 4895
	if (ret < 0)
		return ret;
4896 4897
	if (ret < sizeof (size_buf))
		return -ERANGE;
4898

J
Josh Durgin 已提交
4899
	if (order) {
4900
		*order = size_buf.order;
J
Josh Durgin 已提交
4901 4902
		dout("  order %u", (unsigned int)*order);
	}
4903 4904
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4905 4906
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4907
		(unsigned long long)*snap_size);
4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918

	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);
}

4919 4920 4921 4922 4923 4924 4925 4926 4927 4928
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;

4929 4930 4931
	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);
4932
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4933 4934 4935 4936 4937
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4938 4939
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952

	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;
}

4953 4954 4955 4956 4957 4958 4959
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;
4960
	} __attribute__ ((packed)) features_buf = { 0 };
4961
	u64 unsup;
4962 4963
	int ret;

4964 4965 4966 4967
	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));
4968
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4969 4970
	if (ret < 0)
		return ret;
4971 4972
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4973

4974 4975 4976 4977
	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
4978
		return -ENXIO;
4979
	}
A
Alex Elder 已提交
4980

4981 4982 4983
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4984 4985 4986
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4987 4988 4989 4990 4991 4992 4993 4994 4995 4996

	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);
}

4997 4998 4999 5000 5001 5002 5003 5004
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
5005
	u64 pool_id;
5006
	char *image_id;
5007
	u64 snap_id;
5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024
	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;
	}

5025
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5026 5027 5028
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
5029
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5030 5031 5032 5033
	if (ret < 0)
		goto out_err;

	p = reply_buf;
5034 5035
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
5036
	ceph_decode_64_safe(&p, end, pool_id, out_err);
5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053
	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);
		}

5054
		goto out;	/* No parent?  No problem. */
5055
	}
5056

5057 5058 5059
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5060
	if (pool_id > (u64)U32_MAX) {
5061
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5062
			(unsigned long long)pool_id, U32_MAX);
5063
		goto out_err;
A
Alex Elder 已提交
5064
	}
5065

A
Alex Elder 已提交
5066
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5067 5068 5069 5070
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5071
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5072 5073
	ceph_decode_64_safe(&p, end, overlap, out_err);

5074 5075 5076 5077 5078 5079 5080 5081 5082
	/*
	 * 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
5083 5084
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5085 5086
	} else {
		kfree(image_id);
5087 5088 5089
	}

	/*
5090 5091
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5092 5093 5094
	 */
	if (!overlap) {
		if (parent_spec) {
5095 5096 5097 5098
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5099
		} else {
5100 5101
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5102
		}
A
Alex Elder 已提交
5103
	}
5104 5105
	rbd_dev->parent_overlap = overlap;

5106 5107 5108 5109 5110 5111 5112 5113 5114
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127
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;

5128 5129 5130
	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);
5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143
	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
5144
	obj_size = rbd_obj_bytes(&rbd_dev->header);
5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158
	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;
	}
5159 5160
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5161 5162 5163 5164

	return 0;
}

5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182
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;
}

5183 5184
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
5185
	CEPH_DEFINE_OID_ONSTACK(oid);
5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197
	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
5198 5199
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5200 5201 5202 5203 5204
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5205
	end = image_id + image_id_size;
5206
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5207 5208 5209 5210 5211 5212

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

5213 5214 5215 5216
	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);
5217 5218 5219
	if (ret < 0)
		goto out;
	p = reply_buf;
5220 5221
	end = reply_buf + ret;

5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233
	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;
}

5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263
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);
5264 5265 5266 5267 5268 5269 5270
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288
		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);
}

5289
/*
5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316
 * 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.
5317
 *
5318 5319
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5320
 */
5321
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5322
{
5323 5324 5325 5326 5327
	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;
5328 5329
	int ret;

5330 5331 5332
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5333

5334
	/* Get the pool name; we have to make our own copy of this */
5335

5336 5337 5338
	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);
5339 5340
		return -EIO;
	}
5341 5342
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5343 5344 5345 5346
		return -ENOMEM;

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

5347 5348
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5349
		rbd_warn(rbd_dev, "unable to get image name");
5350

5351
	/* Fetch the snapshot name */
5352

5353
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5354 5355
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5356
		goto out_err;
5357 5358 5359 5360 5361
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5362 5363

	return 0;
5364

5365
out_err:
5366 5367
	kfree(image_name);
	kfree(pool_name);
5368 5369 5370
	return ret;
}

A
Alex Elder 已提交
5371
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394
{
	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;

5395 5396 5397
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
5398
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5399 5400 5401 5402
	if (ret < 0)
		goto out;

	p = reply_buf;
5403 5404
	end = reply_buf + ret;
	ret = -ERANGE;
5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420
	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;
5421
	ret = 0;
5422

5423
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5424 5425 5426 5427 5428 5429 5430 5431
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5432
	ceph_put_snap_context(rbd_dev->header.snapc);
5433 5434 5435
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5436
		(unsigned long long)seq, (unsigned int)snap_count);
5437 5438 5439
out:
	kfree(reply_buf);

5440
	return ret;
5441 5442
}

5443 5444
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5445 5446 5447
{
	size_t size;
	void *reply_buf;
5448
	__le64 snapid;
A
Alex Elder 已提交
5449 5450 5451 5452 5453 5454 5455 5456 5457 5458
	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);

5459
	snapid = cpu_to_le64(snap_id);
5460 5461 5462
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
5463
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5464 5465
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5466
		goto out;
5467
	}
A
Alex Elder 已提交
5468 5469

	p = reply_buf;
5470
	end = reply_buf + ret;
A
Alex Elder 已提交
5471
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5472
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5473 5474
		goto out;

5475
	dout("  snap_id 0x%016llx snap_name = %s\n",
5476
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5477 5478 5479
out:
	kfree(reply_buf);

5480
	return snap_name;
A
Alex Elder 已提交
5481 5482
}

5483
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5484
{
5485
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5486 5487
	int ret;

5488 5489
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5490
		return ret;
5491

5492 5493 5494
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5495
			return ret;
5496 5497
	}

A
Alex Elder 已提交
5498
	ret = rbd_dev_v2_snap_context(rbd_dev);
5499 5500 5501 5502
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5503 5504 5505 5506

	return ret;
}

5507 5508 5509 5510 5511 5512 5513 5514 5515 5516
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);
}

5517 5518 5519
/*
 * 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
5520 5521
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535
 */
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
5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557
/*
 * 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
5558
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5570
/*
5571 5572 5573 5574
 * 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
5575
 *
5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609
 * 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.
5610
 */
5611
static int rbd_add_parse_args(const char *buf,
5612
				struct ceph_options **ceph_opts,
5613 5614
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5615
{
A
Alex Elder 已提交
5616
	size_t len;
5617
	char *options;
5618
	const char *mon_addrs;
5619
	char *snap_name;
5620
	size_t mon_addrs_size;
5621
	struct rbd_spec *spec = NULL;
5622
	struct rbd_options *rbd_opts = NULL;
5623
	struct ceph_options *copts;
5624
	int ret;
5625 5626 5627

	/* The first four tokens are required */

5628
	len = next_token(&buf);
5629 5630 5631 5632
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5633
	mon_addrs = buf;
5634
	mon_addrs_size = len + 1;
5635
	buf += len;
5636

5637
	ret = -EINVAL;
5638 5639
	options = dup_token(&buf, NULL);
	if (!options)
5640
		return -ENOMEM;
5641 5642 5643 5644
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5645

5646 5647
	spec = rbd_spec_alloc();
	if (!spec)
5648
		goto out_mem;
5649 5650 5651 5652

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5653 5654 5655 5656
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5657

A
Alex Elder 已提交
5658
	spec->image_name = dup_token(&buf, NULL);
5659
	if (!spec->image_name)
5660
		goto out_mem;
5661 5662 5663 5664
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5665

5666 5667 5668 5669
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5670
	len = next_token(&buf);
5671
	if (!len) {
5672 5673
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5674
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5675
		ret = -ENAMETOOLONG;
5676
		goto out_err;
5677
	}
5678 5679
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5680
		goto out_mem;
5681 5682
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5683

5684
	/* Initialize all rbd options to the defaults */
5685

5686 5687 5688 5689 5690
	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
5691
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5692
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
A
Alex Elder 已提交
5693

5694
	copts = ceph_parse_options(options, mon_addrs,
5695
					mon_addrs + mon_addrs_size - 1,
5696
					parse_rbd_opts_token, rbd_opts);
5697 5698
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5699 5700
		goto out_err;
	}
5701 5702 5703
	kfree(options);

	*ceph_opts = copts;
5704
	*opts = rbd_opts;
5705
	*rbd_spec = spec;
5706

5707
	return 0;
5708
out_mem:
5709
	ret = -ENOMEM;
A
Alex Elder 已提交
5710
out_err:
5711 5712
	kfree(rbd_opts);
	rbd_spec_put(spec);
5713
	kfree(options);
A
Alex Elder 已提交
5714

5715
	return ret;
5716 5717
}

5718 5719 5720 5721 5722
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5723
	struct ceph_options *opts = rbdc->client->options;
5724 5725 5726 5727 5728 5729 5730
	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) {
5731 5732
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5733 5734 5735 5736
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5737
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5738
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5739 5740
						     newest_epoch,
						     opts->mount_timeout);
5741 5742 5743 5744 5745 5746 5747 5748 5749 5750
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768
/*
 * 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;
5769
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5770
	void *response;
5771
	char *image_id;
5772

A
Alex Elder 已提交
5773 5774 5775
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5776 5777
	 * 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
5778
	 */
5779 5780 5781
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5782
		return 0;
5783
	}
A
Alex Elder 已提交
5784

A
Alex Elder 已提交
5785 5786 5787 5788
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5789 5790 5791 5792 5793 5794
	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
5795 5796 5797 5798 5799 5800 5801 5802 5803 5804

	/* 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;
	}

5805 5806
	/* If it doesn't exist we'll assume it's a format 1 image */

5807 5808 5809
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5810
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5811 5812 5813 5814 5815
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5816
	} else if (ret >= 0) {
5817 5818 5819
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5820
						NULL, GFP_NOIO);
5821
		ret = PTR_ERR_OR_ZERO(image_id);
5822 5823 5824 5825 5826 5827 5828
		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
5829 5830 5831
	}
out:
	kfree(response);
5832
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5833 5834 5835
	return ret;
}

A
Alex Elder 已提交
5836 5837 5838 5839
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5840 5841 5842 5843
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5844
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5845 5846 5847 5848

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

	header = &rbd_dev->header;
5849
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5850 5851 5852 5853 5854 5855
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5856
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5857 5858 5859
{
	int ret;

5860
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5861
	if (ret)
5862 5863
		goto out_err;

5864 5865 5866 5867
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5868
	ret = rbd_dev_v2_features(rbd_dev);
5869
	if (ret)
5870
		goto out_err;
5871

5872 5873 5874 5875 5876 5877 5878
	/* 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;
	}
5879

5880 5881 5882 5883 5884 5885
	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
5886
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5887
	return 0;
I
Ilya Dryomov 已提交
5888

5889
out_err:
A
Alex Elder 已提交
5890
	rbd_dev->header.features = 0;
5891 5892
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5893
	return ret;
5894 5895
}

5896 5897 5898 5899 5900 5901
/*
 * @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
5902
{
5903
	struct rbd_device *parent = NULL;
5904 5905 5906 5907 5908
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5909 5910 5911 5912 5913 5914
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5915
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5916 5917
	if (!parent) {
		ret = -ENOMEM;
5918
		goto out_err;
5919 5920 5921 5922 5923 5924 5925 5926
	}

	/*
	 * 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);
5927

5928
	ret = rbd_dev_image_probe(parent, depth);
5929 5930
	if (ret < 0)
		goto out_err;
5931

5932
	rbd_dev->parent = parent;
5933
	atomic_set(&rbd_dev->parent_ref, 1);
5934
	return 0;
5935

5936
out_err:
5937
	rbd_dev_unparent(rbd_dev);
5938
	rbd_dev_destroy(parent);
5939 5940 5941
	return ret;
}

I
Ilya Dryomov 已提交
5942 5943 5944 5945
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5946
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5947
{
A
Alex Elder 已提交
5948
	int ret;
A
Alex Elder 已提交
5949

5950
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5951

5952 5953 5954
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5955
			goto err_out_unlock;
5956 5957 5958 5959 5960 5961 5962

		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
5963 5964 5965 5966 5967 5968 5969

	/* Set up the blkdev mapping. */

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

5970
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5971 5972
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5973

5974
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5975
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
5976

5977 5978
	dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
	ret = device_add(&rbd_dev->dev);
5979
	if (ret)
5980
		goto err_out_mapping;
A
Alex Elder 已提交
5981 5982 5983

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

5984
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5985
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5986

5987 5988 5989 5990
	spin_lock(&rbd_dev_list_lock);
	list_add_tail(&rbd_dev->node, &rbd_dev_list);
	spin_unlock(&rbd_dev_list_lock);

I
Ilya Dryomov 已提交
5991
	add_disk(rbd_dev->disk);
5992 5993 5994
	pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
		(unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
		rbd_dev->header.features);
A
Alex Elder 已提交
5995 5996

	return ret;
5997

5998 5999
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
6000 6001 6002
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
6003 6004
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
6005 6006
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6007 6008 6009
	return ret;
}

A
Alex Elder 已提交
6010 6011 6012
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
6013
	int ret;
A
Alex Elder 已提交
6014 6015 6016 6017 6018

	/* 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)
6019 6020
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
6021
	else
6022 6023
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
6024

6025
	return ret;
A
Alex Elder 已提交
6026 6027
}

6028 6029
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6030 6031 6032 6033 6034
	rbd_dev_unprobe(rbd_dev);
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

6035 6036 6037
	rbd_dev_destroy(rbd_dev);
}

6038 6039
/*
 * Probe for the existence of the header object for the given rbd
6040 6041 6042
 * 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.
6043
 */
6044
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6045 6046 6047 6048
{
	int ret;

	/*
A
Alex Elder 已提交
6049 6050 6051 6052
	 * 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.
6053 6054 6055
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6056 6057
		return ret;

A
Alex Elder 已提交
6058 6059 6060 6061
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6062
	if (!depth) {
6063
		ret = rbd_register_watch(rbd_dev);
6064 6065 6066 6067 6068
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6069
			goto err_out_format;
6070
		}
6071
	}
6072

6073
	ret = rbd_dev_header_info(rbd_dev);
6074
	if (ret)
6075
		goto err_out_watch;
A
Alex Elder 已提交
6076

6077 6078 6079 6080 6081 6082
	/*
	 * 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.
	 */
6083
	if (!depth)
6084 6085 6086
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6087 6088 6089 6090 6091 6092
	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
6093
		goto err_out_probe;
6094
	}
6095

6096 6097 6098 6099 6100 6101 6102 6103 6104
	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.
		 */
6105
		if (!depth && rbd_dev->parent_spec)
6106 6107 6108 6109
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6110
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6111 6112 6113 6114
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6115
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6116
	return 0;
6117

A
Alex Elder 已提交
6118 6119
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6120
err_out_watch:
6121
	if (!depth)
6122
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6123 6124
err_out_format:
	rbd_dev->image_format = 0;
6125 6126
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6127 6128 6129
	return ret;
}

6130 6131 6132
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6133
{
6134
	struct rbd_device *rbd_dev = NULL;
6135
	struct ceph_options *ceph_opts = NULL;
6136
	struct rbd_options *rbd_opts = NULL;
6137
	struct rbd_spec *spec = NULL;
6138
	struct rbd_client *rbdc;
6139
	bool read_only;
6140
	int rc;
6141 6142 6143 6144 6145

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

	/* parse add command */
6146
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6147
	if (rc < 0)
6148
		goto out;
6149

6150 6151 6152
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6153
		goto err_out_args;
6154
	}
6155 6156

	/* pick the pool */
6157
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6158 6159 6160
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6161
		goto err_out_client;
6162
	}
A
Alex Elder 已提交
6163
	spec->pool_id = (u64)rc;
6164

6165
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6166 6167
	if (!rbd_dev) {
		rc = -ENOMEM;
6168
		goto err_out_client;
6169
	}
6170 6171
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6172
	rbd_opts = NULL;	/* rbd_dev now owns this */
6173

6174 6175 6176 6177 6178 6179
	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
6180
	down_write(&rbd_dev->header_rwsem);
6181
	rc = rbd_dev_image_probe(rbd_dev, 0);
6182 6183
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6184
		goto err_out_rbd_dev;
6185
	}
6186

6187 6188
	/* If we are mapping a snapshot it must be marked read-only */

6189
	read_only = rbd_dev->opts->read_only;
6190 6191 6192 6193
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

6194
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
6195
	if (rc) {
6196
		/*
6197
		 * rbd_unregister_watch() can't be moved into
6198 6199 6200
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
6201
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6202
		rbd_dev_image_release(rbd_dev);
6203
		goto out;
A
Alex Elder 已提交
6204 6205
	}

6206 6207 6208 6209
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6210

6211 6212
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6213
err_out_client:
6214
	rbd_put_client(rbdc);
6215
err_out_args:
6216
	rbd_spec_put(spec);
6217
	kfree(rbd_opts);
6218
	goto out;
6219 6220
}

6221 6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237
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);
}

6238
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6239 6240
{
	rbd_free_disk(rbd_dev);
6241 6242 6243 6244 6245

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

6246
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6247
	device_del(&rbd_dev->dev);
A
Alex Elder 已提交
6248
	rbd_dev_mapping_clear(rbd_dev);
6249 6250
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
6251 6252
}

6253 6254
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6255
	while (rbd_dev->parent) {
6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267
		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
6268
		rbd_assert(second);
6269
		rbd_dev_image_release(second);
A
Alex Elder 已提交
6270 6271 6272 6273
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6274 6275 6276 6277 6278
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6279 6280 6281
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6282 6283
{
	struct rbd_device *rbd_dev = NULL;
6284 6285
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6286
	char opt_buf[6];
6287
	bool already = false;
M
Mike Christie 已提交
6288
	bool force = false;
6289
	int ret;
6290

M
Mike Christie 已提交
6291 6292 6293 6294 6295
	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");
6296
		return -EINVAL;
M
Mike Christie 已提交
6297 6298 6299 6300 6301 6302 6303 6304 6305
	}
	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;
		}
	}
6306

6307 6308 6309 6310 6311 6312 6313 6314
	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;
		}
6315
	}
6316 6317
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6318
		if (rbd_dev->open_count && !force)
6319 6320
			ret = -EBUSY;
		else
6321 6322
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6323 6324 6325
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6326
	if (ret < 0 || already)
6327
		return ret;
6328

M
Mike Christie 已提交
6329 6330 6331 6332 6333 6334 6335 6336 6337
	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);
	}

6338 6339 6340 6341
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
6342
	rbd_unregister_watch(rbd_dev);
6343

6344 6345 6346 6347 6348 6349
	/*
	 * Don't free anything from rbd_dev->disk until after all
	 * notifies are completely processed. Otherwise
	 * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
	 * in a potential use after free of rbd_dev->disk or rbd_dev.
	 */
6350
	rbd_dev_device_release(rbd_dev);
6351
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
6352

6353
	return count;
6354 6355
}

6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372
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);
}

6373 6374
/*
 * create control files in sysfs
6375
 * /sys/bus/rbd/...
6376 6377 6378
 */
static int rbd_sysfs_init(void)
{
6379
	int ret;
6380

6381
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6382
	if (ret < 0)
6383
		return ret;
6384

6385 6386 6387
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6388 6389 6390 6391 6392 6393

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6394
	bus_unregister(&rbd_bus_type);
6395
	device_unregister(&rbd_root_dev);
6396 6397
}

6398 6399 6400
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6401
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6402 6403 6404 6405
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6406
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6407 6408 6409 6410 6411
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6412
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6413
	if (rbd_segment_name_cache)
6414
		return 0;
6415
out_err:
6416 6417
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6418

6419 6420 6421
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

6422 6423 6424 6425 6426
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6427 6428 6429 6430
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

6431 6432 6433 6434
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6435 6436 6437 6438 6439
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
6440
static int __init rbd_init(void)
6441 6442 6443
{
	int rc;

6444 6445 6446 6447
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6448

6449
	rc = rbd_slab_init();
6450 6451
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6452

6453 6454
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6455
	 * rbd devices * queue depth, so leave @max_active at default.
6456 6457 6458 6459 6460 6461 6462
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6463 6464 6465 6466
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6467
			goto err_out_wq;
6468 6469 6470
		}
	}

6471 6472
	rc = rbd_sysfs_init();
	if (rc)
6473 6474 6475 6476 6477 6478
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6479

I
Ilya Dryomov 已提交
6480 6481
	return 0;

6482 6483 6484
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6485 6486
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6487 6488
err_out_slab:
	rbd_slab_exit();
6489
	return rc;
6490 6491
}

A
Alex Elder 已提交
6492
static void __exit rbd_exit(void)
6493
{
I
Ilya Dryomov 已提交
6494
	ida_destroy(&rbd_dev_id_ida);
6495
	rbd_sysfs_cleanup();
6496 6497
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6498
	destroy_workqueue(rbd_wq);
6499
	rbd_slab_exit();
6500 6501 6502 6503 6504
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6505
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6506 6507 6508 6509 6510
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>");

6511
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6512
MODULE_LICENSE("GPL");