rbd.c 166.0 KB
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/*
   rbd.c -- Export ceph rados objects as a Linux block device


   based on drivers/block/osdblk.c:

   Copyright 2009 Red Hat, Inc.

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

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

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



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

#include <linux/ceph/libceph.h>
#include <linux/ceph/osd_client.h>
#include <linux/ceph/mon_client.h>
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#include <linux/ceph/cls_lock_client.h>
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#include <linux/ceph/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
Alex Elder 已提交
1278 1279
		name = NULL;
	}
1280

A
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1281 1282
	return name;
}
1283

A
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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 1634
	struct ceph_osd_request *osd_req = obj_request->osd_req;

	dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
1635 1636 1637 1638
	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);
	}
1639
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
Alex Elder 已提交
1640 1641 1642 1643
}

static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1644

A
Alex Elder 已提交
1645
	dout("%s: img %p\n", __func__, img_request);
1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661

	/*
	 * 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
1662 1663 1664 1665 1666 1667
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
Alex Elder 已提交
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684
/*
 * 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;
}

1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699
/*
 * 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;
}

1700 1701 1702 1703 1704 1705
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1706 1707 1708 1709 1710 1711
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1712 1713 1714 1715 1716 1717
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1718 1719 1720 1721 1722 1723
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1724 1725 1726 1727 1728 1729
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1730 1731 1732 1733 1734 1735
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746
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;
}

1747 1748 1749
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1750 1751 1752
	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1753 1754
	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
1755
		xferred, length);
1756
	/*
1757 1758 1759 1760 1761 1762
	 * 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.
1763
	 */
A
Alex Elder 已提交
1764
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1765
	if (obj_request->result == -ENOENT) {
A
Alex Elder 已提交
1766 1767 1768 1769
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1770
		obj_request->result = 0;
A
Alex Elder 已提交
1771 1772 1773 1774 1775
	} 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);
1776
	}
1777
	obj_request->xferred = length;
1778 1779 1780
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1781 1782
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1783 1784
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
A
Alex Elder 已提交
1785 1786
	if (obj_request->callback)
		obj_request->callback(obj_request);
1787 1788
	else
		complete_all(&obj_request->completion);
A
Alex Elder 已提交
1789 1790
}

1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806
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);
}

1807
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1808
{
A
Alex Elder 已提交
1809
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1810
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1811 1812 1813 1814 1815
	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
1816
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1817
	}
A
Alex Elder 已提交
1818 1819 1820 1821

	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
1822 1823
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1824 1825
		rbd_img_parent_read(obj_request);
	else if (img_request)
1826 1827 1828
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1829 1830
}

1831
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1832
{
1833 1834 1835
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1836 1837
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1838 1839
	 */
	obj_request->xferred = obj_request->length;
1840
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1841 1842
}

1843 1844 1845 1846 1847 1848 1849 1850 1851
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;
1852 1853 1854
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1855 1856 1857
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1858 1859 1860 1861
/*
 * 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.
 */
1862
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1863
{
A
Alex Elder 已提交
1864
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1865 1866 1867
	obj_request_done_set(obj_request);
}

I
Ilya Dryomov 已提交
1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
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);
}

1878
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
Alex Elder 已提交
1879 1880 1881 1882
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

1883
	dout("%s: osd_req %p\n", __func__, osd_req);
A
Alex Elder 已提交
1884
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1885 1886 1887 1888 1889 1890
	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
1891

1892 1893
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1894

1895 1896
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1897 1898
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1899
	 */
1900
	obj_request->xferred = osd_req->r_ops[0].outdata_len;
A
Alex Elder 已提交
1901
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1902

1903
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1904 1905
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1906
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1907
		break;
1908
	case CEPH_OSD_OP_SETALLOCHINT:
1909 1910
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
			   osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1911
		/* fall through */
A
Alex Elder 已提交
1912
	case CEPH_OSD_OP_WRITE:
1913
	case CEPH_OSD_OP_WRITEFULL:
1914
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1915
		break;
A
Alex Elder 已提交
1916
	case CEPH_OSD_OP_STAT:
1917
		rbd_osd_stat_callback(obj_request);
A
Alex Elder 已提交
1918
		break;
1919 1920 1921 1922 1923
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1924
	case CEPH_OSD_OP_CALL:
I
Ilya Dryomov 已提交
1925 1926
		rbd_osd_call_callback(obj_request);
		break;
A
Alex Elder 已提交
1927
	default:
1928
		rbd_warn(NULL, "%s: unsupported op %hu",
A
Alex Elder 已提交
1929 1930 1931 1932
			obj_request->object_name, (unsigned short) opcode);
		break;
	}

1933
	if (obj_request_done_test(obj_request))
A
Alex Elder 已提交
1934 1935 1936
		rbd_obj_request_complete(obj_request);
}

1937
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1938
{
1939
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1940

1941 1942
	rbd_assert(obj_request_img_data_test(obj_request));
	osd_req->r_snapid = obj_request->img_request->snap_id;
1943 1944 1945 1946 1947 1948
}

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

1949 1950
	osd_req->r_mtime = CURRENT_TIME;
	osd_req->r_data_offset = obj_request->offset;
A
Alex Elder 已提交
1951 1952
}

1953 1954 1955 1956 1957 1958
/*
 * 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
1959 1960
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1961
					enum obj_operation_type op_type,
1962
					unsigned int num_ops,
A
Alex Elder 已提交
1963
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1964 1965 1966 1967 1968
{
	struct ceph_snap_context *snapc = NULL;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;

1969 1970
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1971
		struct rbd_img_request *img_request = obj_request->img_request;
1972 1973 1974 1975 1976
		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
1977
		snapc = img_request->snapc;
A
Alex Elder 已提交
1978 1979
	}

G
Guangliang Zhao 已提交
1980
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1981 1982

	/* Allocate and initialize the request, for the num_ops ops */
A
Alex Elder 已提交
1983 1984

	osdc = &rbd_dev->rbd_client->client->osdc;
1985
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
1986
					  GFP_NOIO);
A
Alex Elder 已提交
1987
	if (!osd_req)
1988
		goto fail;
A
Alex Elder 已提交
1989

1990
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
A
Alex Elder 已提交
1991
		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
A
Alex Elder 已提交
1992
	else
A
Alex Elder 已提交
1993 1994 1995 1996 1997
		osd_req->r_flags = CEPH_OSD_FLAG_READ;

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

1998
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
1999 2000 2001
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
A
Alex Elder 已提交
2002

2003 2004 2005
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

A
Alex Elder 已提交
2006
	return osd_req;
2007 2008 2009 2010

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
A
Alex Elder 已提交
2011 2012
}

2013
/*
2014 2015 2016 2017
 * 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.
2018 2019 2020 2021 2022 2023 2024 2025 2026
 */
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;
2027
	int num_osd_ops = 3;
2028 2029 2030 2031

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
2032 2033
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
2034

2035 2036 2037 2038
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

	/* Allocate and initialize the request, for all the ops */
2039 2040 2041 2042

	snapc = img_request->snapc;
	rbd_dev = img_request->rbd_dev;
	osdc = &rbd_dev->rbd_client->client->osdc;
2043
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2044
						false, GFP_NOIO);
2045
	if (!osd_req)
2046
		goto fail;
2047 2048 2049 2050 2051

	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;

2052
	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2053 2054 2055
	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto fail;
2056

2057 2058 2059
	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
		goto fail;

2060
	return osd_req;
2061 2062 2063 2064

fail:
	ceph_osdc_put_request(osd_req);
	return NULL;
2065 2066 2067
}


A
Alex Elder 已提交
2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085
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,
						u64 offset, u64 length,
						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;
2086
	name = kmalloc(size, GFP_NOIO);
2087
	if (!name)
A
Alex Elder 已提交
2088 2089
		return NULL;

2090
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2091 2092 2093 2094 2095
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2096 2097 2098
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->offset = offset;
	obj_request->length = length;
2099
	obj_request->flags = 0;
A
Alex Elder 已提交
2100 2101 2102
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2103
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2104 2105
	kref_init(&obj_request->kref);

A
Alex Elder 已提交
2106 2107 2108
	dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
		offset, length, (int)type, obj_request);

A
Alex Elder 已提交
2109 2110 2111 2112 2113 2114 2115 2116 2117
	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
2118 2119
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2120 2121 2122 2123 2124 2125 2126 2127
	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) {
2128 2129
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2130 2131 2132 2133
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2134
	case OBJ_REQUEST_PAGES:
2135 2136 2137
		/* img_data requests don't own their page array */
		if (obj_request->pages &&
		    !obj_request_img_data_test(obj_request))
2138 2139 2140
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2141 2142
	}

2143
	kfree(obj_request->object_name);
2144 2145
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2146 2147
}

A
Alex Elder 已提交
2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158
/* 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;
}

2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180
/*
 * 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
2181
		rbd_warn(rbd_dev, "parent reference underflow");
2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193
}

/*
 * 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)
{
2194
	int counter = 0;
2195 2196 2197 2198

	if (!rbd_dev->parent_spec)
		return false;

2199 2200 2201 2202
	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);
2203 2204

	if (counter < 0)
2205
		rbd_warn(rbd_dev, "parent reference overflow");
2206

2207
	return counter > 0;
2208 2209
}

A
Alex Elder 已提交
2210 2211 2212 2213 2214
/*
 * 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
2215 2216
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2217
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2218
					enum obj_operation_type op_type,
2219
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2220 2221 2222
{
	struct rbd_img_request *img_request;

2223
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2224 2225 2226 2227 2228 2229 2230
	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
2231
	img_request->flags = 0;
2232 2233 2234 2235
	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
2236
		img_request_write_set(img_request);
2237
		img_request->snapc = snapc;
A
Alex Elder 已提交
2238
	} else {
A
Alex Elder 已提交
2239
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2240
	}
2241
	if (rbd_dev_parent_get(rbd_dev))
2242
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2243 2244 2245
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2246
	img_request->result = 0;
A
Alex Elder 已提交
2247 2248 2249 2250
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2251
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2252
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2253

A
Alex Elder 已提交
2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264
	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
2265 2266
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2267 2268
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2269
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2270

2271 2272 2273 2274 2275
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2276 2277
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2278
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2279

2280
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2281 2282
}

2283 2284 2285 2286 2287 2288 2289 2290 2291 2292
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;

2293
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2294
						length, OBJ_OP_READ, NULL);
2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319
	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);
}

2320 2321
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2322
	struct rbd_img_request *img_request;
2323 2324
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2325
	bool more;
2326

2327 2328 2329
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2330 2331 2332 2333 2334
	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
2335 2336
		enum obj_operation_type op_type;

2337 2338 2339 2340 2341 2342
		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;
2343

2344
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2345 2346
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2347
		rbd_warn(rbd_dev, "  result %d xferred %x",
2348 2349 2350
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2351 2352 2353 2354 2355
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2356 2357
	}

A
Alex Elder 已提交
2358 2359 2360 2361 2362
	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
2363 2364 2365 2366

		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
2367 2368 2369
	}

	return more;
2370 2371
}

2372 2373 2374 2375 2376 2377
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;

2378
	rbd_assert(obj_request_img_data_test(obj_request));
2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396
	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;
2397
		more = rbd_img_obj_end_request(obj_request);
2398 2399 2400 2401 2402 2403 2404
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2405
	rbd_img_request_put(img_request);
2406 2407 2408 2409 2410

	if (!more)
		rbd_img_request_complete(img_request);
}

2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429
/*
 * 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) {
2430 2431 2432
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446
			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) {
2447 2448 2449 2450
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2451 2452 2453 2454 2455 2456 2457
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2458
	if (opcode == CEPH_OSD_OP_DELETE)
2459
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2460 2461 2462 2463
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478
	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);
}

2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489
/*
 * 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
2490 2491 2492 2493
{
	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
2494
	struct bio *bio_list = NULL;
2495
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2496
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2497
	enum obj_operation_type op_type;
2498
	u64 img_offset;
A
Alex Elder 已提交
2499 2500
	u64 resid;

2501 2502
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2503

2504
	img_offset = img_request->offset;
A
Alex Elder 已提交
2505
	resid = img_request->length;
A
Alex Elder 已提交
2506
	rbd_assert(resid > 0);
2507
	op_type = rbd_img_request_op_type(img_request);
2508 2509 2510

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2511 2512
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2513
	} else if (type == OBJ_REQUEST_PAGES) {
2514 2515 2516
		pages = data_desc;
	}

A
Alex Elder 已提交
2517
	while (resid) {
2518
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2519 2520 2521 2522
		const char *object_name;
		u64 offset;
		u64 length;

2523
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2524 2525
		if (!object_name)
			goto out_unwind;
2526 2527
		offset = rbd_segment_offset(rbd_dev, img_offset);
		length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2528
		obj_request = rbd_obj_request_create(object_name,
2529
						offset, length, type);
2530 2531
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2532 2533
		if (!obj_request)
			goto out_unwind;
2534

2535 2536 2537 2538 2539
		/*
		 * 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
2540

2541 2542 2543 2544 2545 2546 2547 2548 2549
		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,
2550
								GFP_NOIO);
2551
			if (!obj_request->bio_list)
2552
				goto out_unwind;
2553
		} else if (type == OBJ_REQUEST_PAGES) {
2554 2555 2556 2557 2558 2559 2560 2561 2562
			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
2563

G
Guangliang Zhao 已提交
2564 2565 2566
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2567
		if (!osd_req)
2568
			goto out_unwind;
2569

2570
		obj_request->osd_req = osd_req;
2571
		obj_request->callback = rbd_img_obj_callback;
2572
		obj_request->img_offset = img_offset;
2573

2574
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2575

2576
		img_offset += length;
A
Alex Elder 已提交
2577 2578 2579 2580 2581 2582 2583
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2584
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2585 2586 2587 2588

	return -ENOMEM;
}

2589
static void
I
Ilya Dryomov 已提交
2590
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2591 2592 2593
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2594
	struct page **pages;
2595 2596
	u32 page_count;

I
Ilya Dryomov 已提交
2597 2598
	dout("%s: obj %p\n", __func__, obj_request);

2599 2600
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2601 2602 2603 2604 2605 2606 2607
	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);

2608 2609
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2610
	obj_request->copyup_pages = NULL;
2611 2612 2613 2614
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2615 2616 2617 2618 2619 2620 2621 2622 2623 2624

	/*
	 * 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
2625
	obj_request_done_set(obj_request);
2626 2627
}

2628 2629 2630 2631
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2632 2633
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2634
	struct page **pages;
2635
	enum obj_operation_type op_type;
2636
	u32 page_count;
2637
	int img_result;
2638
	u64 parent_length;
2639 2640 2641 2642 2643 2644 2645 2646

	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;
2647 2648 2649
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2650 2651 2652

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2653
	rbd_assert(obj_request_type_valid(orig_request->type));
2654
	img_result = img_request->result;
2655
	parent_length = img_request->length;
2656
	rbd_assert(img_result || parent_length == img_request->xferred);
2657
	rbd_img_request_put(img_request);
2658

2659 2660
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2661 2662
	rbd_assert(rbd_dev);

2663 2664 2665 2666 2667 2668 2669
	/*
	 * 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);
2670 2671
		rbd_obj_request_submit(orig_request);
		return;
2672
	}
2673

2674
	if (img_result)
2675 2676
		goto out_err;

2677 2678
	/*
	 * The original osd request is of no use to use any more.
2679
	 * We need a new one that can hold the three ops in a copyup
2680 2681 2682
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2683
	img_result = -ENOMEM;
2684 2685 2686
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2687
	rbd_osd_req_destroy(orig_request->osd_req);
2688 2689
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2690
	orig_request->copyup_page_count = page_count;
2691

2692
	/* Initialize the copyup op */
2693

2694
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2695
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2696
						false, false);
2697

2698
	/* Add the other op(s) */
2699

2700 2701
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2702 2703 2704

	/* All set, send it off. */

2705 2706
	rbd_obj_request_submit(orig_request);
	return;
2707 2708

out_err:
2709
	ceph_release_page_vector(pages, page_count);
2710
	rbd_obj_request_error(orig_request, img_result);
2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723
}

/*
 * 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.
 *
2724 2725
 * If an error occurs, it is recorded as the result of the original
 * object request in rbd_img_obj_exists_callback().
2726 2727 2728
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
2729
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743
	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
2744
	length = rbd_obj_bytes(&rbd_dev->header);
2745

A
Alex Elder 已提交
2746 2747 2748 2749 2750 2751 2752 2753 2754 2755
	/*
	 * 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;
	}

2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768
	/*
	 * 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;
2769 2770
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2771 2772 2773 2774 2775 2776
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
2777

2778
	parent_request->copyup_pages = pages;
2779
	parent_request->copyup_page_count = page_count;
2780
	parent_request->callback = rbd_img_obj_parent_read_full_callback;
2781

2782 2783 2784 2785 2786
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2787
	parent_request->copyup_page_count = 0;
2788 2789 2790 2791 2792 2793 2794 2795 2796 2797
	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;
}

2798 2799 2800
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2801
	struct rbd_device *rbd_dev;
2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812
	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;
2813
	rbd_obj_request_put(orig_request);
2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824
	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);

2825 2826
	/*
	 * If the overlap has become 0 (most likely because the
2827 2828
	 * image has been flattened) we need to re-submit the
	 * original request.
2829 2830 2831
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2832 2833
		rbd_obj_request_submit(orig_request);
		return;
2834
	}
2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845

	/*
	 * 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);
2846 2847
	} else {
		goto fail_orig_request;
2848 2849 2850 2851 2852 2853
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2854 2855 2856 2857 2858 2859 2860
	result = rbd_img_obj_request_submit(orig_request);
	if (result)
		goto fail_orig_request;

	return;

fail_orig_request:
2861
	rbd_obj_request_error(orig_request, result);
2862 2863 2864 2865
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
2866
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2867
	struct rbd_obj_request *stat_request;
2868
	struct page **pages;
2869 2870 2871 2872
	u32 page_count;
	size_t size;
	int ret;

2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884
	stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
					      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;
	}

2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895
	/*
	 * 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);
2896 2897 2898 2899
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto fail_stat_request;
	}
2900

2901 2902 2903
	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);
2904 2905 2906 2907 2908 2909 2910

	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;

2911 2912
	rbd_obj_request_submit(stat_request);
	return 0;
2913

2914 2915
fail_stat_request:
	rbd_obj_request_put(stat_request);
2916 2917 2918
	return ret;
}

2919
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2920
{
2921 2922
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
2923

2924
	/* Reads */
2925 2926
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2927 2928 2929 2930 2931 2932
		return true;

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

2933
	/*
2934 2935
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2936
	 */
2937 2938
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2939

2940 2941 2942 2943 2944 2945 2946 2947
	/*
	 * 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;

2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960
	/*
	 * 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)
{
2961 2962 2963
	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request_type_valid(obj_request->type));
	rbd_assert(obj_request->img_request);
2964

2965
	if (img_obj_request_simple(obj_request)) {
2966 2967
		rbd_obj_request_submit(obj_request);
		return 0;
2968 2969 2970
	}

	/*
2971 2972 2973 2974
	 * 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.
2975
	 */
2976
	if (obj_request_known_test(obj_request))
2977 2978 2979
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
2980 2981 2982 2983

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
2984 2985 2986
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
2987
	struct rbd_obj_request *next_obj_request;
2988
	int ret = 0;
A
Alex Elder 已提交
2989

A
Alex Elder 已提交
2990
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
2991

2992 2993
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2994
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
2995
		if (ret)
2996
			goto out_put_ireq;
A
Alex Elder 已提交
2997 2998
	}

2999 3000 3001
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
3002
}
A
Alex Elder 已提交
3003 3004 3005 3006

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
3007 3008
	struct rbd_device *rbd_dev;
	u64 obj_end;
3009 3010
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
3011 3012 3013

	rbd_assert(img_request_child_test(img_request));

3014 3015
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
3016
	obj_request = img_request->obj_request;
3017 3018 3019 3020 3021 3022 3023 3024 3025
	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
3026 3027
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
3028 3029
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
3030 3031
		rbd_obj_request_submit(obj_request);
		return;
3032
	}
A
Alex Elder 已提交
3033

3034
	obj_request->result = img_result;
A
Alex Elder 已提交
3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052
	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
3053

3054
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
3055
	} else {
3056
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
3057 3058
	}
out:
A
Alex Elder 已提交
3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070
	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);
3071
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3072 3073

	/* rbd_read_finish(obj_request, obj_request->length); */
3074
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
3075
						obj_request->img_offset,
3076
						obj_request->length);
A
Alex Elder 已提交
3077 3078 3079 3080
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

3081 3082 3083 3084 3085 3086
	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
3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102
	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
3103

3104
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
3105

3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145
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
3146
{
3147
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3148 3149
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
	char cookie[32];
3150
	int ret;
A
Alex Elder 已提交
3151

3152
	WARN_ON(__rbd_is_lock_owner(rbd_dev));
3153

3154 3155 3156 3157
	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);
3158
	if (ret)
3159
		return ret;
A
Alex Elder 已提交
3160

3161 3162 3163 3164
	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
3165 3166
}

3167 3168 3169 3170
/*
 * lock_rwsem must be held for write
 */
static int rbd_unlock(struct rbd_device *rbd_dev)
3171
{
3172
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3173
	char cookie[32];
3174 3175
	int ret;

3176
	WARN_ON(!__rbd_is_lock_owner(rbd_dev));
3177

3178
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3179

3180 3181 3182 3183 3184 3185
	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;
3186 3187
	}

3188 3189 3190
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
	return 0;
3191 3192
}

3193 3194 3195 3196
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)
3197 3198
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3199 3200 3201 3202
	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;
3203

3204
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3205

3206 3207 3208 3209 3210
	/* 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);
3211

3212 3213 3214
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3215 3216
}

3217 3218
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
3219
{
3220 3221
	struct page **reply_pages;
	size_t reply_len;
3222

3223 3224 3225
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
3226

3227 3228 3229 3230
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
3231

3232
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3233 3234
}

3235
static void rbd_notify_released_lock(struct work_struct *work)
3236
{
3237 3238
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
3239

3240
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3241 3242
}

3243
static int rbd_request_lock(struct rbd_device *rbd_dev)
3244
{
3245 3246 3247
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
3248 3249
	int ret;

3250
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3251

3252 3253 3254 3255
	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);
3256
		goto out;
3257
	}
3258

3259 3260 3261 3262
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
3263

3264 3265 3266 3267
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
3268

3269 3270
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
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 3544 3545 3546 3547
			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);
3548
	/*
3549
	 * Ensure that all in-flight IO is flushed.
3550
	 *
3551 3552
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
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 3697 3698 3699 3700
	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
3701

3702 3703
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3704
				   buf, buf_size);
3705
	if (ret)
3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728
		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;
3729
	u8 struct_v = 0;
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 3784 3785 3786 3787
	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
3788 3789
}

3790 3791
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3792
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3793
{
3794
	struct rbd_device *rbd_dev = arg;
3795

3796
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3797

3798 3799 3800 3801
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3802 3803 3804 3805
	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;
3806

3807
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3808
	}
3809
	mutex_unlock(&rbd_dev->watch_mutex);
3810 3811
}

3812
/*
3813
 * watch_mutex must be locked
3814
 */
3815
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3816 3817
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3818
	struct ceph_osd_linger_request *handle;
3819

3820
	rbd_assert(!rbd_dev->watch_handle);
3821
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3822

3823 3824 3825 3826 3827
	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);
3828

3829
	rbd_dev->watch_handle = handle;
3830 3831 3832
	return 0;
}

3833 3834 3835 3836
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3837
{
3838 3839
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3840

3841 3842
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3843

3844 3845 3846
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3847

3848
	rbd_dev->watch_handle = NULL;
3849 3850
}

3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869
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)
3870
{
3871 3872 3873
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3874 3875 3876 3877
	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);
3878 3879 3880 3881
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3882
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3883 3884 3885 3886 3887 3888 3889
	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
3890 3891

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3892 3893
}

3894 3895 3896 3897
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);
3898
	bool was_lock_owner = false;
3899
	bool need_to_wake = false;
3900 3901 3902 3903
	int ret;

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

3904 3905 3906 3907
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		was_lock_owner = rbd_release_lock(rbd_dev);

3908
	mutex_lock(&rbd_dev->watch_mutex);
3909 3910 3911 3912
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
	}
3913 3914 3915 3916

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3917
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3918 3919 3920
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
			need_to_wake = true;
		} else {
3921 3922 3923
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3924 3925 3926
		}
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
3927 3928
	}

3929
	need_to_wake = true;
3930 3931 3932 3933 3934 3935 3936 3937
	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);

3938 3939 3940 3941 3942 3943 3944
	if (was_lock_owner) {
		ret = rbd_try_lock(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "reregisteration lock failed: %d",
				 ret);
	}

3945
out:
3946
	up_write(&rbd_dev->lock_rwsem);
3947 3948
	if (need_to_wake)
		wake_requests(rbd_dev, true);
3949 3950
}

3951
/*
3952 3953
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3954 3955
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3956 3957
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3958
			     const char *method_name,
3959
			     const void *outbound,
3960
			     size_t outbound_size,
3961
			     void *inbound,
3962
			     size_t inbound_size)
3963
{
3964 3965 3966
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3967 3968 3969
	int ret;

	/*
3970 3971 3972 3973 3974
	 * 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.
3975
	 */
3976 3977 3978
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3979

3980 3981 3982
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3983

3984
		memcpy(page_address(req_page), outbound, outbound_size);
3985
	}
A
Alex Elder 已提交
3986

3987 3988 3989 3990 3991 3992
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3993

3994 3995 3996 3997 3998 3999 4000
	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;
	}
4001

4002 4003 4004
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
4005 4006 4007
	return ret;
}

4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026
/*
 * 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);
4027 4028 4029
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

4030 4031 4032
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
4033
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
4034
{
C
Christoph Hellwig 已提交
4035 4036
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
4037
	struct rbd_img_request *img_request;
4038
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
4039 4040
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
4041
	enum obj_operation_type op_type;
4042
	u64 mapping_size;
I
Ilya Dryomov 已提交
4043
	bool must_be_locked;
A
Alex Elder 已提交
4044 4045
	int result;

C
Christoph Hellwig 已提交
4046 4047 4048 4049 4050 4051 4052
	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
4053
	if (req_op(rq) == REQ_OP_DISCARD)
4054
		op_type = OBJ_OP_DISCARD;
M
Mike Christie 已提交
4055
	else if (req_op(rq) == REQ_OP_WRITE)
G
Guangliang Zhao 已提交
4056 4057 4058 4059
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
4060
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4061

I
Ilya Dryomov 已提交
4062 4063 4064 4065 4066
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4067

G
Guangliang Zhao 已提交
4068
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
4069

G
Guangliang Zhao 已提交
4070
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
4071 4072 4073
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
4074
		}
I
Ilya Dryomov 已提交
4075 4076
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
4077

I
Ilya Dryomov 已提交
4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089
	/*
	 * 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
4090

I
Ilya Dryomov 已提交
4091 4092 4093 4094 4095 4096
	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
4097

C
Christoph Hellwig 已提交
4098 4099
	blk_mq_start_request(rq);

4100 4101
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4102
	if (op_type != OBJ_OP_READ) {
4103 4104
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
4105
		must_be_locked = rbd_is_lock_supported(rbd_dev);
I
Ilya Dryomov 已提交
4106 4107 4108
	} else {
		must_be_locked = rbd_dev->opts->lock_on_read &&
					rbd_is_lock_supported(rbd_dev);
4109 4110 4111 4112
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4113
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4114
			 length, mapping_size);
I
Ilya Dryomov 已提交
4115 4116 4117
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4118

4119 4120
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
4121 4122
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
4123
			rbd_wait_state_locked(rbd_dev);
4124 4125 4126 4127 4128 4129 4130

		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;
		}
4131 4132
	}

G
Guangliang Zhao 已提交
4133
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4134
					     snapc);
I
Ilya Dryomov 已提交
4135 4136
	if (!img_request) {
		result = -ENOMEM;
4137
		goto err_unlock;
I
Ilya Dryomov 已提交
4138 4139
	}
	img_request->rq = rq;
4140
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4141

4142 4143 4144 4145 4146 4147
	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
4148 4149
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4150

I
Ilya Dryomov 已提交
4151 4152 4153
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4154

4155 4156
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4157
	return;
A
Alex Elder 已提交
4158

I
Ilya Dryomov 已提交
4159 4160
err_img_request:
	rbd_img_request_put(img_request);
4161 4162 4163
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4164 4165 4166
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4167
			 obj_op_name(op_type), length, offset, result);
4168
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4169 4170
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
4171
}
A
Alex Elder 已提交
4172

C
Christoph Hellwig 已提交
4173 4174
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4175
{
C
Christoph Hellwig 已提交
4176 4177
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4178

C
Christoph Hellwig 已提交
4179 4180
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
4181 4182
}

4183 4184 4185 4186 4187 4188 4189
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

4190 4191
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
4192
		del_gendisk(disk);
4193 4194
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
4195
		blk_mq_free_tag_set(&rbd_dev->tag_set);
4196
	}
4197 4198 4199
	put_disk(disk);
}

4200
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4201 4202 4203
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
4204 4205

{
4206 4207 4208 4209
	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);
4210 4211
	int ret;

4212 4213 4214
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
4215

4216 4217 4218
	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
4219

4220
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
4221
	if (ret)
4222
		goto out_req;
4223

4224 4225 4226 4227 4228
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
4229

4230 4231 4232 4233 4234 4235 4236 4237
	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);
4238

4239 4240
out_req:
	ceph_osdc_put_request(req);
4241 4242 4243
	return ret;
}

4244
/*
A
Alex Elder 已提交
4245 4246 4247
 * 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.
4248
 */
4249
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4250
{
4251
	struct rbd_image_header_ondisk *ondisk = NULL;
4252
	u32 snap_count = 0;
4253 4254 4255
	u64 names_size = 0;
	u32 want_count;
	int ret;
4256

A
Alex Elder 已提交
4257
	/*
4258 4259 4260 4261 4262
	 * 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
4263
	 */
4264 4265 4266 4267 4268 4269 4270 4271 4272 4273
	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
4274
			return -ENOMEM;
4275

4276 4277
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
4278
		if (ret < 0)
A
Alex Elder 已提交
4279
			goto out;
A
Alex Elder 已提交
4280
		if ((size_t)ret < size) {
4281
			ret = -ENXIO;
A
Alex Elder 已提交
4282 4283
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4284
			goto out;
4285 4286 4287
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4288
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4289
			goto out;
4290
		}
4291

4292 4293 4294 4295
		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
4296

A
Alex Elder 已提交
4297 4298
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4299 4300 4301
	kfree(ondisk);

	return ret;
4302 4303
}

4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322
/*
 * 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);
}

4323 4324 4325 4326 4327
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4328 4329 4330
	 * 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.
4331
	 */
I
Ilya Dryomov 已提交
4332 4333
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4334 4335 4336 4337 4338 4339 4340
		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
4341
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4342
{
4343
	u64 mapping_size;
A
Alex Elder 已提交
4344 4345
	int ret;

4346
	down_write(&rbd_dev->header_rwsem);
4347
	mapping_size = rbd_dev->mapping.size;
4348 4349

	ret = rbd_dev_header_info(rbd_dev);
4350
	if (ret)
4351
		goto out;
4352

4353 4354 4355 4356 4357 4358 4359
	/*
	 * 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)
4360
			goto out;
4361 4362
	}

4363
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4364
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4365 4366 4367 4368
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4369

4370
out:
4371
	up_write(&rbd_dev->header_rwsem);
4372
	if (!ret && mapping_size != rbd_dev->mapping.size)
4373
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4374

4375
	return ret;
A
Alex Elder 已提交
4376 4377
}

C
Christoph Hellwig 已提交
4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392
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,
};

4393 4394 4395 4396
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4397
	u64 segment_size;
C
Christoph Hellwig 已提交
4398
	int err;
4399 4400

	/* create gendisk info */
4401 4402 4403
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4404
	if (!disk)
A
Alex Elder 已提交
4405
		return -ENOMEM;
4406

A
Alex Elder 已提交
4407
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4408
		 rbd_dev->dev_id);
4409
	disk->major = rbd_dev->major;
4410
	disk->first_minor = rbd_dev->minor;
4411 4412
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4413 4414 4415
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4416 4417
	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
4418
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4419
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4420
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4421 4422 4423 4424 4425
	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)
4426
		goto out_disk;
4427

C
Christoph Hellwig 已提交
4428 4429 4430 4431 4432 4433
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4434 4435
	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
4436

4437
	/* set io sizes to object size */
A
Alex Elder 已提交
4438 4439
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4440
	q->limits.max_sectors = queue_max_hw_sectors(q);
I
Ilya Dryomov 已提交
4441
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
4442 4443 4444
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4445

4446 4447 4448 4449
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
4450
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4451
	q->limits.discard_zeroes_data = 1;
4452

4453 4454 4455
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
		q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

4456 4457 4458 4459 4460 4461 4462
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4463 4464
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4465 4466
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4467
	return err;
4468 4469
}

4470 4471 4472 4473
/*
  sysfs
*/

A
Alex Elder 已提交
4474 4475 4476 4477 4478
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4479 4480 4481
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4482
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4483

A
Alex Elder 已提交
4484 4485
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4486 4487
}

A
Alex Elder 已提交
4488 4489 4490 4491 4492 4493 4494 4495 4496 4497
/*
 * 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
4498
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4499 4500
}

4501 4502 4503
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4504
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4505

A
Alex Elder 已提交
4506 4507 4508 4509
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4510 4511 4512 4513 4514 4515
}

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
4516

4517
	return sprintf(buf, "%d\n", rbd_dev->minor);
4518 4519
}

4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530
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));
}

4531 4532
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4533
{
A
Alex Elder 已提交
4534
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4535

4536
	return sprintf(buf, "client%lld\n",
4537
		       ceph_client_gid(rbd_dev->rbd_client->client));
4538 4539
}

4540 4541 4542 4543 4544 4545 4546 4547
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);
}

4548 4549 4550 4551 4552 4553
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);
4554 4555
}

4556 4557
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4558
{
A
Alex Elder 已提交
4559
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4560

4561
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4562 4563
}

4564 4565 4566 4567 4568
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);

4569
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4570
			(unsigned long long) rbd_dev->spec->pool_id);
4571 4572
}

4573 4574 4575
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4576
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4577

A
Alex Elder 已提交
4578 4579 4580 4581
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4582 4583
}

A
Alex Elder 已提交
4584 4585 4586 4587 4588
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);

4589
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4590 4591
}

A
Alex Elder 已提交
4592 4593 4594 4595
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4596 4597 4598 4599
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4600
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4601

4602
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4603 4604
}

4605 4606 4607 4608 4609 4610 4611 4612
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);
}

4613
/*
4614 4615 4616
 * 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)".
4617 4618
 */
static ssize_t rbd_parent_show(struct device *dev,
4619 4620
			       struct device_attribute *attr,
			       char *buf)
4621 4622
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4623
	ssize_t count = 0;
4624

4625
	if (!rbd_dev->parent)
4626 4627
		return sprintf(buf, "(no parent image)\n");

4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643
	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;
4644 4645
}

4646 4647 4648 4649 4650
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
4651
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4652
	int ret;
4653

A
Alex Elder 已提交
4654
	ret = rbd_dev_refresh(rbd_dev);
4655
	if (ret)
4656
		return ret;
4657

4658
	return size;
4659
}
4660

4661
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4662
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4663
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4664
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4665
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4666
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4667
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4668
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4669
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4670
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4671
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4672
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4673 4674
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4675
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4676
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4677 4678 4679

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4680
	&dev_attr_features.attr,
4681
	&dev_attr_major.attr,
4682
	&dev_attr_minor.attr,
4683
	&dev_attr_client_addr.attr,
4684
	&dev_attr_client_id.attr,
4685
	&dev_attr_cluster_fsid.attr,
4686
	&dev_attr_config_info.attr,
4687
	&dev_attr_pool.attr,
4688
	&dev_attr_pool_id.attr,
4689
	&dev_attr_name.attr,
A
Alex Elder 已提交
4690
	&dev_attr_image_id.attr,
4691
	&dev_attr_current_snap.attr,
4692
	&dev_attr_snap_id.attr,
4693
	&dev_attr_parent.attr,
4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706
	&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
};

4707
static void rbd_dev_release(struct device *dev);
4708 4709 4710 4711

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4712
	.release	= rbd_dev_release,
4713 4714
};

4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735
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;
4736 4737 4738

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754
	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);
}

4755
static void rbd_dev_free(struct rbd_device *rbd_dev)
4756
{
4757
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4758
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4759

4760
	ceph_oid_destroy(&rbd_dev->header_oid);
4761
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4762
	kfree(rbd_dev->config_info);
4763

4764 4765 4766 4767
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780
}

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);
4781 4782 4783 4784 4785 4786 4787 4788 4789 4790

	/*
	 * 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);
}

4791 4792
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4793 4794 4795
{
	struct rbd_device *rbd_dev;

4796
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4797 4798 4799 4800 4801 4802 4803
	if (!rbd_dev)
		return NULL;

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

4804
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4805
	ceph_oid_init(&rbd_dev->header_oid);
4806
	rbd_dev->header_oloc.pool = spec->pool_id;
4807

4808 4809 4810 4811
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4812 4813 4814 4815 4816 4817 4818 4819
	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);

4820 4821 4822 4823 4824
	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);

4825
	rbd_dev->rbd_client = rbdc;
4826
	rbd_dev->spec = spec;
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 4854 4855 4856 4857
	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;
4858

4859 4860
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4861

4862
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4863
	return rbd_dev;
4864 4865 4866 4867 4868 4869

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4870 4871 4872 4873
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4874 4875
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4876 4877
}

4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892
/*
 * 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 };

4893 4894 4895 4896
	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));
4897
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4898 4899
	if (ret < 0)
		return ret;
4900 4901
	if (ret < sizeof (size_buf))
		return -ERANGE;
4902

J
Josh Durgin 已提交
4903
	if (order) {
4904
		*order = size_buf.order;
J
Josh Durgin 已提交
4905 4906
		dout("  order %u", (unsigned int)*order);
	}
4907 4908
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4909 4910
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4911
		(unsigned long long)*snap_size);
4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922

	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);
}

4923 4924 4925 4926 4927 4928 4929 4930 4931 4932
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;

4933 4934 4935
	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);
4936
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4937 4938 4939 4940 4941
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4942 4943
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956

	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;
}

4957 4958 4959 4960 4961 4962 4963
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;
4964
	} __attribute__ ((packed)) features_buf = { 0 };
4965
	u64 unsup;
4966 4967
	int ret;

4968 4969 4970 4971
	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));
4972
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4973 4974
	if (ret < 0)
		return ret;
4975 4976
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4977

4978 4979 4980 4981
	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
4982
		return -ENXIO;
4983
	}
A
Alex Elder 已提交
4984

4985 4986 4987
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4988 4989 4990
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4991 4992 4993 4994 4995 4996 4997 4998 4999 5000

	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);
}

5001 5002 5003 5004 5005 5006 5007 5008
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
5009
	u64 pool_id;
5010
	char *image_id;
5011
	u64 snap_id;
5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028
	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;
	}

5029
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5030 5031 5032
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
5033
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5034 5035 5036 5037
	if (ret < 0)
		goto out_err;

	p = reply_buf;
5038 5039
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
5040
	ceph_decode_64_safe(&p, end, pool_id, out_err);
5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057
	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);
		}

5058
		goto out;	/* No parent?  No problem. */
5059
	}
5060

5061 5062 5063
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5064
	if (pool_id > (u64)U32_MAX) {
5065
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5066
			(unsigned long long)pool_id, U32_MAX);
5067
		goto out_err;
A
Alex Elder 已提交
5068
	}
5069

A
Alex Elder 已提交
5070
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5071 5072 5073 5074
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5075
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5076 5077
	ceph_decode_64_safe(&p, end, overlap, out_err);

5078 5079 5080 5081 5082 5083 5084 5085 5086
	/*
	 * 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
5087 5088
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5089 5090
	} else {
		kfree(image_id);
5091 5092 5093
	}

	/*
5094 5095
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5096 5097 5098
	 */
	if (!overlap) {
		if (parent_spec) {
5099 5100 5101 5102
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5103
		} else {
5104 5105
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5106
		}
A
Alex Elder 已提交
5107
	}
5108 5109
	rbd_dev->parent_overlap = overlap;

5110 5111 5112 5113 5114 5115 5116 5117 5118
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131
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;

5132 5133 5134
	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);
5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147
	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
5148
	obj_size = rbd_obj_bytes(&rbd_dev->header);
5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162
	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;
	}
5163 5164
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5165 5166 5167 5168

	return 0;
}

5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182 5183 5184 5185 5186
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;
}

5187 5188
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
5189
	CEPH_DEFINE_OID_ONSTACK(oid);
5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201
	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
5202 5203
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5204 5205 5206 5207 5208
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5209
	end = image_id + image_id_size;
5210
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5211 5212 5213 5214 5215 5216

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

5217 5218 5219 5220
	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);
5221 5222 5223
	if (ret < 0)
		goto out;
	p = reply_buf;
5224 5225
	end = reply_buf + ret;

5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237
	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;
}

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 5264 5265 5266 5267
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);
5268 5269 5270 5271 5272 5273 5274
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292
		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);
}

5293
/*
5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320
 * 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.
5321
 *
5322 5323
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5324
 */
5325
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5326
{
5327 5328 5329 5330 5331
	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;
5332 5333
	int ret;

5334 5335 5336
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5337

5338
	/* Get the pool name; we have to make our own copy of this */
5339

5340 5341 5342
	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);
5343 5344
		return -EIO;
	}
5345 5346
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5347 5348 5349 5350
		return -ENOMEM;

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

5351 5352
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5353
		rbd_warn(rbd_dev, "unable to get image name");
5354

5355
	/* Fetch the snapshot name */
5356

5357
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5358 5359
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5360
		goto out_err;
5361 5362 5363 5364 5365
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5366 5367

	return 0;
5368

5369
out_err:
5370 5371
	kfree(image_name);
	kfree(pool_name);
5372 5373 5374
	return ret;
}

A
Alex Elder 已提交
5375
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5376 5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398
{
	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;

5399 5400 5401
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
5402
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5403 5404 5405 5406
	if (ret < 0)
		goto out;

	p = reply_buf;
5407 5408
	end = reply_buf + ret;
	ret = -ERANGE;
5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423 5424
	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;
5425
	ret = 0;
5426

5427
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5428 5429 5430 5431 5432 5433 5434 5435
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5436
	ceph_put_snap_context(rbd_dev->header.snapc);
5437 5438 5439
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5440
		(unsigned long long)seq, (unsigned int)snap_count);
5441 5442 5443
out:
	kfree(reply_buf);

5444
	return ret;
5445 5446
}

5447 5448
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5449 5450 5451
{
	size_t size;
	void *reply_buf;
5452
	__le64 snapid;
A
Alex Elder 已提交
5453 5454 5455 5456 5457 5458 5459 5460 5461 5462
	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);

5463
	snapid = cpu_to_le64(snap_id);
5464 5465 5466
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
5467
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5468 5469
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5470
		goto out;
5471
	}
A
Alex Elder 已提交
5472 5473

	p = reply_buf;
5474
	end = reply_buf + ret;
A
Alex Elder 已提交
5475
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5476
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5477 5478
		goto out;

5479
	dout("  snap_id 0x%016llx snap_name = %s\n",
5480
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5481 5482 5483
out:
	kfree(reply_buf);

5484
	return snap_name;
A
Alex Elder 已提交
5485 5486
}

5487
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5488
{
5489
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5490 5491
	int ret;

5492 5493
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5494
		return ret;
5495

5496 5497 5498
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5499
			return ret;
5500 5501
	}

A
Alex Elder 已提交
5502
	ret = rbd_dev_v2_snap_context(rbd_dev);
5503 5504 5505 5506
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5507 5508 5509 5510

	return ret;
}

5511 5512 5513 5514 5515 5516 5517 5518 5519 5520
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);
}

5521 5522 5523
/*
 * 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
5524 5525
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539
 */
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
5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557 5558 5559 5560 5561
/*
 * 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
5562
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5574
/*
5575 5576 5577 5578
 * 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
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 5610 5611 5612 5613
 * 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.
5614
 */
5615
static int rbd_add_parse_args(const char *buf,
5616
				struct ceph_options **ceph_opts,
5617 5618
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5619
{
A
Alex Elder 已提交
5620
	size_t len;
5621
	char *options;
5622
	const char *mon_addrs;
5623
	char *snap_name;
5624
	size_t mon_addrs_size;
5625
	struct rbd_spec *spec = NULL;
5626
	struct rbd_options *rbd_opts = NULL;
5627
	struct ceph_options *copts;
5628
	int ret;
5629 5630 5631

	/* The first four tokens are required */

5632
	len = next_token(&buf);
5633 5634 5635 5636
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5637
	mon_addrs = buf;
5638
	mon_addrs_size = len + 1;
5639
	buf += len;
5640

5641
	ret = -EINVAL;
5642 5643
	options = dup_token(&buf, NULL);
	if (!options)
5644
		return -ENOMEM;
5645 5646 5647 5648
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5649

5650 5651
	spec = rbd_spec_alloc();
	if (!spec)
5652
		goto out_mem;
5653 5654 5655 5656

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5657 5658 5659 5660
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5661

A
Alex Elder 已提交
5662
	spec->image_name = dup_token(&buf, NULL);
5663
	if (!spec->image_name)
5664
		goto out_mem;
5665 5666 5667 5668
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5669

5670 5671 5672 5673
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5674
	len = next_token(&buf);
5675
	if (!len) {
5676 5677
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5678
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5679
		ret = -ENAMETOOLONG;
5680
		goto out_err;
5681
	}
5682 5683
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5684
		goto out_mem;
5685 5686
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5687

5688
	/* Initialize all rbd options to the defaults */
5689

5690 5691 5692 5693 5694
	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
5695
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5696
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
A
Alex Elder 已提交
5697

5698
	copts = ceph_parse_options(options, mon_addrs,
5699
					mon_addrs + mon_addrs_size - 1,
5700
					parse_rbd_opts_token, rbd_opts);
5701 5702
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5703 5704
		goto out_err;
	}
5705 5706 5707
	kfree(options);

	*ceph_opts = copts;
5708
	*opts = rbd_opts;
5709
	*rbd_spec = spec;
5710

5711
	return 0;
5712
out_mem:
5713
	ret = -ENOMEM;
A
Alex Elder 已提交
5714
out_err:
5715 5716
	kfree(rbd_opts);
	rbd_spec_put(spec);
5717
	kfree(options);
A
Alex Elder 已提交
5718

5719
	return ret;
5720 5721
}

5722 5723 5724 5725 5726
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5727
	struct ceph_options *opts = rbdc->client->options;
5728 5729 5730 5731 5732 5733 5734
	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) {
5735 5736
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5737 5738 5739 5740
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5741
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5742
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5743 5744
						     newest_epoch,
						     opts->mount_timeout);
5745 5746 5747 5748 5749 5750 5751 5752 5753 5754
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772
/*
 * 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;
5773
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5774
	void *response;
5775
	char *image_id;
5776

A
Alex Elder 已提交
5777 5778 5779
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5780 5781
	 * 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
5782
	 */
5783 5784 5785
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5786
		return 0;
5787
	}
A
Alex Elder 已提交
5788

A
Alex Elder 已提交
5789 5790 5791 5792
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5793 5794 5795 5796 5797 5798
	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
5799 5800 5801 5802 5803 5804 5805 5806 5807 5808

	/* 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;
	}

5809 5810
	/* If it doesn't exist we'll assume it's a format 1 image */

5811 5812 5813
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5814
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5815 5816 5817 5818 5819
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5820
	} else if (ret >= 0) {
5821 5822 5823
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5824
						NULL, GFP_NOIO);
5825
		ret = PTR_ERR_OR_ZERO(image_id);
5826 5827 5828 5829 5830 5831 5832
		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
5833 5834 5835
	}
out:
	kfree(response);
5836
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5837 5838 5839
	return ret;
}

A
Alex Elder 已提交
5840 5841 5842 5843
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5844 5845 5846 5847
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5848
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5849 5850 5851 5852

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

	header = &rbd_dev->header;
5853
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5854 5855 5856 5857 5858 5859
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5860
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5861 5862 5863
{
	int ret;

5864
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5865
	if (ret)
5866 5867
		goto out_err;

5868 5869 5870 5871
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5872
	ret = rbd_dev_v2_features(rbd_dev);
5873
	if (ret)
5874
		goto out_err;
5875

5876 5877 5878 5879 5880 5881 5882
	/* 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;
	}
5883

5884 5885 5886 5887 5888 5889
	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
5890
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5891
	return 0;
I
Ilya Dryomov 已提交
5892

5893
out_err:
A
Alex Elder 已提交
5894
	rbd_dev->header.features = 0;
5895 5896
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5897
	return ret;
5898 5899
}

5900 5901 5902 5903 5904 5905
/*
 * @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
5906
{
5907
	struct rbd_device *parent = NULL;
5908 5909 5910 5911 5912
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5913 5914 5915 5916 5917 5918
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5919
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5920 5921
	if (!parent) {
		ret = -ENOMEM;
5922
		goto out_err;
5923 5924 5925 5926 5927 5928 5929 5930
	}

	/*
	 * 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);
5931

5932
	ret = rbd_dev_image_probe(parent, depth);
5933 5934
	if (ret < 0)
		goto out_err;
5935

5936
	rbd_dev->parent = parent;
5937
	atomic_set(&rbd_dev->parent_ref, 1);
5938
	return 0;
5939

5940
out_err:
5941
	rbd_dev_unparent(rbd_dev);
5942
	rbd_dev_destroy(parent);
5943 5944 5945
	return ret;
}

I
Ilya Dryomov 已提交
5946 5947 5948 5949
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5950
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5951
{
A
Alex Elder 已提交
5952
	int ret;
A
Alex Elder 已提交
5953

5954
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5955

5956 5957 5958
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5959
			goto err_out_unlock;
5960 5961 5962 5963 5964 5965 5966

		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
5967 5968 5969 5970 5971 5972 5973

	/* Set up the blkdev mapping. */

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

5974
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5975 5976
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5977

5978
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5979
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
5980

5981 5982
	dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
	ret = device_add(&rbd_dev->dev);
5983
	if (ret)
5984
		goto err_out_mapping;
A
Alex Elder 已提交
5985 5986 5987

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

5988
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5989
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5990

5991 5992 5993 5994
	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
5995
	add_disk(rbd_dev->disk);
5996 5997 5998
	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
5999 6000

	return ret;
6001

6002 6003
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
6004 6005 6006
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
6007 6008
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
6009 6010
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
6011 6012 6013
	return ret;
}

A
Alex Elder 已提交
6014 6015 6016
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
6017
	int ret;
A
Alex Elder 已提交
6018 6019 6020 6021 6022

	/* 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)
6023 6024
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
6025
	else
6026 6027
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
6028

6029
	return ret;
A
Alex Elder 已提交
6030 6031
}

6032 6033
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6034 6035 6036 6037 6038
	rbd_dev_unprobe(rbd_dev);
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

6039 6040 6041
	rbd_dev_destroy(rbd_dev);
}

6042 6043
/*
 * Probe for the existence of the header object for the given rbd
6044 6045 6046
 * 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.
6047
 */
6048
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6049 6050 6051 6052
{
	int ret;

	/*
A
Alex Elder 已提交
6053 6054 6055 6056
	 * 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.
6057 6058 6059
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6060 6061
		return ret;

A
Alex Elder 已提交
6062 6063 6064 6065
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6066
	if (!depth) {
6067
		ret = rbd_register_watch(rbd_dev);
6068 6069 6070 6071 6072
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6073
			goto err_out_format;
6074
		}
6075
	}
6076

6077
	ret = rbd_dev_header_info(rbd_dev);
6078
	if (ret)
6079
		goto err_out_watch;
A
Alex Elder 已提交
6080

6081 6082 6083 6084 6085 6086
	/*
	 * 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.
	 */
6087
	if (!depth)
6088 6089 6090
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6091 6092 6093 6094 6095 6096
	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
6097
		goto err_out_probe;
6098
	}
6099

6100 6101 6102 6103 6104 6105 6106 6107 6108
	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.
		 */
6109
		if (!depth && rbd_dev->parent_spec)
6110 6111 6112 6113
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6114
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6115 6116 6117 6118
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6119
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6120
	return 0;
6121

A
Alex Elder 已提交
6122 6123
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6124
err_out_watch:
6125
	if (!depth)
6126
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6127 6128
err_out_format:
	rbd_dev->image_format = 0;
6129 6130
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6131 6132 6133
	return ret;
}

6134 6135 6136
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6137
{
6138
	struct rbd_device *rbd_dev = NULL;
6139
	struct ceph_options *ceph_opts = NULL;
6140
	struct rbd_options *rbd_opts = NULL;
6141
	struct rbd_spec *spec = NULL;
6142
	struct rbd_client *rbdc;
6143
	bool read_only;
6144
	int rc;
6145 6146 6147 6148 6149

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

	/* parse add command */
6150
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6151
	if (rc < 0)
6152
		goto out;
6153

6154 6155 6156
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6157
		goto err_out_args;
6158
	}
6159 6160

	/* pick the pool */
6161
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6162 6163 6164
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6165
		goto err_out_client;
6166
	}
A
Alex Elder 已提交
6167
	spec->pool_id = (u64)rc;
6168

6169
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6170 6171
	if (!rbd_dev) {
		rc = -ENOMEM;
6172
		goto err_out_client;
6173
	}
6174 6175
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6176
	rbd_opts = NULL;	/* rbd_dev now owns this */
6177

6178 6179 6180 6181 6182 6183
	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
6184
	down_write(&rbd_dev->header_rwsem);
6185
	rc = rbd_dev_image_probe(rbd_dev, 0);
6186 6187
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6188
		goto err_out_rbd_dev;
6189
	}
6190

6191 6192
	/* If we are mapping a snapshot it must be marked read-only */

6193
	read_only = rbd_dev->opts->read_only;
6194 6195 6196 6197
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

6198
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
6199
	if (rc) {
6200
		/*
6201
		 * rbd_unregister_watch() can't be moved into
6202 6203 6204
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
6205
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6206
		rbd_dev_image_release(rbd_dev);
6207
		goto out;
A
Alex Elder 已提交
6208 6209
	}

6210 6211 6212 6213
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6214

6215 6216
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6217
err_out_client:
6218
	rbd_put_client(rbdc);
6219
err_out_args:
6220
	rbd_spec_put(spec);
6221
	kfree(rbd_opts);
6222
	goto out;
6223 6224
}

6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241
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);
}

6242
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6243 6244
{
	rbd_free_disk(rbd_dev);
6245 6246 6247 6248 6249

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

6250
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6251
	device_del(&rbd_dev->dev);
A
Alex Elder 已提交
6252
	rbd_dev_mapping_clear(rbd_dev);
6253 6254
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
6255 6256
}

6257 6258
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6259
	while (rbd_dev->parent) {
6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 6271
		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
6272
		rbd_assert(second);
6273
		rbd_dev_image_release(second);
A
Alex Elder 已提交
6274 6275 6276 6277
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6278 6279 6280 6281 6282
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6283 6284 6285
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6286 6287
{
	struct rbd_device *rbd_dev = NULL;
6288 6289
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6290
	char opt_buf[6];
6291
	bool already = false;
M
Mike Christie 已提交
6292
	bool force = false;
6293
	int ret;
6294

M
Mike Christie 已提交
6295 6296 6297 6298 6299
	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");
6300
		return -EINVAL;
M
Mike Christie 已提交
6301 6302 6303 6304 6305 6306 6307 6308 6309
	}
	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;
		}
	}
6310

6311 6312 6313 6314 6315 6316 6317 6318
	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;
		}
6319
	}
6320 6321
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6322
		if (rbd_dev->open_count && !force)
6323 6324
			ret = -EBUSY;
		else
6325 6326
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6327 6328 6329
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6330
	if (ret < 0 || already)
6331
		return ret;
6332

M
Mike Christie 已提交
6333 6334 6335 6336 6337 6338 6339 6340 6341
	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);
	}

6342 6343 6344 6345
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
6346
	rbd_unregister_watch(rbd_dev);
6347

6348 6349 6350 6351 6352 6353
	/*
	 * 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.
	 */
6354
	rbd_dev_device_release(rbd_dev);
6355
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
6356

6357
	return count;
6358 6359
}

6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372 6373 6374 6375 6376
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);
}

6377 6378
/*
 * create control files in sysfs
6379
 * /sys/bus/rbd/...
6380 6381 6382
 */
static int rbd_sysfs_init(void)
{
6383
	int ret;
6384

6385
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6386
	if (ret < 0)
6387
		return ret;
6388

6389 6390 6391
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6392 6393 6394 6395 6396 6397

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6398
	bus_unregister(&rbd_bus_type);
6399
	device_unregister(&rbd_root_dev);
6400 6401
}

6402 6403 6404
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6405
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6406 6407 6408 6409
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6410
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6411 6412 6413 6414 6415
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6416
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6417
	if (rbd_segment_name_cache)
6418
		return 0;
6419
out_err:
6420 6421
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6422

6423 6424 6425
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

6426 6427 6428 6429 6430
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6431 6432 6433 6434
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

6435 6436 6437 6438
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6439 6440 6441 6442 6443
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
6444
static int __init rbd_init(void)
6445 6446 6447
{
	int rc;

6448 6449 6450 6451
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6452

6453
	rc = rbd_slab_init();
6454 6455
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6456

6457 6458
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6459
	 * rbd devices * queue depth, so leave @max_active at default.
6460 6461 6462 6463 6464 6465 6466
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6467 6468 6469 6470
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6471
			goto err_out_wq;
6472 6473 6474
		}
	}

6475 6476
	rc = rbd_sysfs_init();
	if (rc)
6477 6478 6479 6480 6481 6482
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6483

I
Ilya Dryomov 已提交
6484 6485
	return 0;

6486 6487 6488
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6489 6490
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6491 6492
err_out_slab:
	rbd_slab_exit();
6493
	return rc;
6494 6495
}

A
Alex Elder 已提交
6496
static void __exit rbd_exit(void)
6497
{
I
Ilya Dryomov 已提交
6498
	ida_destroy(&rbd_dev_id_ida);
6499
	rbd_sysfs_cleanup();
6500 6501
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6502
	destroy_workqueue(rbd_wq);
6503
	rbd_slab_exit();
6504 6505 6506 6507 6508
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6509
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6510 6511 6512 6513 6514
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>");

6515
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6516
MODULE_LICENSE("GPL");