rbd.c 165.4 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
{
1260 1261
	const char *name_format = rbd_dev->image_format == 1 ?
				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
A
Alex Elder 已提交
1262 1263 1264
	char *name;
	u64 segment;
	int ret;
1265

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

A
Alex Elder 已提交
1279 1280
	return name;
}
1281

A
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1282 1283
static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
I
Ilya Dryomov 已提交
1284
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
1285

A
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1286 1287 1288 1289 1290 1291
	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
1292
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
A
Alex Elder 已提交
1293 1294 1295

	offset &= segment_size - 1;

A
Alex Elder 已提交
1296
	rbd_assert(length <= U64_MAX - offset);
A
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1297 1298 1299 1300
	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
}

/*
 * 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)
{
1323 1324
	struct bio_vec bv;
	struct bvec_iter iter;
1325 1326 1327 1328 1329
	unsigned long flags;
	void *buf;
	int pos = 0;

	while (chain) {
1330 1331
		bio_for_each_segment(bv, chain, iter) {
			if (pos + bv.bv_len > start_ofs) {
1332
				int remainder = max(start_ofs - pos, 0);
1333
				buf = bvec_kmap_irq(&bv, &flags);
1334
				memset(buf + remainder, 0,
1335 1336
				       bv.bv_len - remainder);
				flush_dcache_page(bv.bv_page);
1337
				bvec_kunmap_irq(buf, &flags);
1338
			}
1339
			pos += bv.bv_len;
1340 1341 1342 1343 1344 1345
		}

		chain = chain->bi_next;
	}
}

A
Alex Elder 已提交
1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363
/*
 * 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;

1364 1365
		page_offset = offset & ~PAGE_MASK;
		length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
A
Alex Elder 已提交
1366 1367 1368
		local_irq_save(flags);
		kaddr = kmap_atomic(*page);
		memset(kaddr + page_offset, 0, length);
1369
		flush_dcache_page(*page);
A
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1370 1371 1372 1373 1374 1375 1376 1377
		kunmap_atomic(kaddr);
		local_irq_restore(flags);

		offset += length;
		page++;
	}
}

1378
/*
A
Alex Elder 已提交
1379 1380
 * Clone a portion of a bio, starting at the given byte offset
 * and continuing for the number of bytes indicated.
1381
 */
A
Alex Elder 已提交
1382 1383 1384 1385
static struct bio *bio_clone_range(struct bio *bio_src,
					unsigned int offset,
					unsigned int len,
					gfp_t gfpmask)
1386
{
A
Alex Elder 已提交
1387 1388
	struct bio *bio;

K
Kent Overstreet 已提交
1389
	bio = bio_clone(bio_src, gfpmask);
A
Alex Elder 已提交
1390 1391
	if (!bio)
		return NULL;	/* ENOMEM */
1392

K
Kent Overstreet 已提交
1393
	bio_advance(bio, offset);
1394
	bio->bi_iter.bi_size = len;
A
Alex Elder 已提交
1395 1396 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

	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 */

1425
	if (!bi || off >= bi->bi_iter.bi_size || !len)
A
Alex Elder 已提交
1426
		return NULL;		/* Nothing to clone */
1427

A
Alex Elder 已提交
1428 1429 1430 1431 1432
	end = &chain;
	while (len) {
		unsigned int bi_size;
		struct bio *bio;

1433 1434
		if (!bi) {
			rbd_warn(NULL, "bio_chain exhausted with %u left", len);
A
Alex Elder 已提交
1435
			goto out_err;	/* EINVAL; ran out of bio's */
1436
		}
1437
		bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
A
Alex Elder 已提交
1438 1439 1440 1441 1442 1443
		bio = bio_clone_range(bi, off, bi_size, gfpmask);
		if (!bio)
			goto out_err;	/* ENOMEM */

		*end = bio;
		end = &bio->bi_next;
1444

A
Alex Elder 已提交
1445
		off += bi_size;
1446
		if (off == bi->bi_iter.bi_size) {
A
Alex Elder 已提交
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457
			bi = bi->bi_next;
			off = 0;
		}
		len -= bi_size;
	}
	*bio_src = bi;
	*offset = off;

	return chain;
out_err:
	bio_chain_put(chain);
1458 1459 1460 1461

	return NULL;
}

1462 1463 1464 1465 1466
/*
 * 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
1467
static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1468
{
A
Alex Elder 已提交
1469
	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1470 1471
		struct rbd_device *rbd_dev;

A
Alex Elder 已提交
1472
		rbd_dev = obj_request->img_request->rbd_dev;
1473
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1474 1475 1476 1477
			obj_request);
	}
}

A
Alex Elder 已提交
1478
static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1479 1480
{
	smp_mb();
A
Alex Elder 已提交
1481
	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1482 1483
}

A
Alex Elder 已提交
1484
static void obj_request_done_set(struct rbd_obj_request *obj_request)
1485
{
A
Alex Elder 已提交
1486 1487
	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1488

A
Alex Elder 已提交
1489 1490
		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1491
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1492 1493 1494 1495
			obj_request);
	}
}

A
Alex Elder 已提交
1496
static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1497 1498
{
	smp_mb();
A
Alex Elder 已提交
1499
	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1500 1501
}

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
/*
 * 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;
}

1533 1534 1535 1536 1537 1538 1539 1540
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
1541 1542
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1543 1544
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1545 1546 1547 1548 1549 1550 1551
	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
1552 1553
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
A
Alex Elder 已提交
1554 1555 1556
	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1557 1558 1559 1560 1561 1562 1563
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);
}

1564 1565
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
1566 1567 1568 1569
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
1570 1571
	dout("%s: img %p (was %d)\n", __func__, img_request,
		atomic_read(&img_request->kref.refcount));
1572 1573 1574 1575
	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
1576 1577 1578 1579 1580
}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1581 1582
	rbd_assert(obj_request->img_request == NULL);

1583
	/* Image request now owns object's original reference */
A
Alex Elder 已提交
1584
	obj_request->img_request = img_request;
1585
	obj_request->which = img_request->obj_request_count;
1586 1587
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
A
Alex Elder 已提交
1588
	rbd_assert(obj_request->which != BAD_WHICH);
1589 1590
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
A
Alex Elder 已提交
1591 1592
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1593 1594 1595 1596 1597 1598
}

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);
1599

A
Alex Elder 已提交
1600 1601
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1602
	list_del(&obj_request->links);
1603 1604 1605 1606
	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;
1607
	rbd_assert(obj_request_img_data_test(obj_request));
A
Alex Elder 已提交
1608 1609
	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1610
	obj_request->callback = NULL;
A
Alex Elder 已提交
1611 1612 1613 1614 1615 1616
	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1617
	case OBJ_REQUEST_NODATA:
A
Alex Elder 已提交
1618
	case OBJ_REQUEST_BIO:
1619
	case OBJ_REQUEST_PAGES:
A
Alex Elder 已提交
1620 1621 1622 1623 1624 1625
		return true;
	default:
		return false;
	}
}

1626 1627
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

1628
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1629
{
1630 1631
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1632 1633 1634
	dout("%s %p \"%s\" %llu~%llu osd_req %p\n", __func__,
	     obj_request, obj_request->object_name, obj_request->offset,
	     obj_request->length, osd_req);
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
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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
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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
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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
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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 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
static struct ceph_osd_request *
__rbd_osd_req_create(struct rbd_device *rbd_dev,
		     struct ceph_snap_context *snapc,
		     int num_ops, unsigned int flags,
		     struct rbd_obj_request *obj_request)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct ceph_osd_request *req;

	req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false, GFP_NOIO);
	if (!req)
		return NULL;

	req->r_flags = flags;
	req->r_callback = rbd_osd_req_callback;
	req->r_priv = obj_request;

	req->r_base_oloc.pool = rbd_dev->layout.pool_id;
	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, "%s",
			     obj_request->object_name))
		goto err_req;

	if (ceph_osdc_alloc_messages(req, GFP_NOIO))
		goto err_req;

	return req;

err_req:
	ceph_osdc_put_request(req);
	return NULL;
}

1985 1986 1987 1988 1989 1990
/*
 * 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
1991 1992
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1993
					enum obj_operation_type op_type,
1994
					unsigned int num_ops,
A
Alex Elder 已提交
1995
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1996 1997 1998
{
	struct ceph_snap_context *snapc = NULL;

1999 2000
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
2001
		struct rbd_img_request *img_request = obj_request->img_request;
2002 2003 2004 2005 2006
		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
2007
		snapc = img_request->snapc;
A
Alex Elder 已提交
2008 2009
	}

G
Guangliang Zhao 已提交
2010
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
2011

2012 2013 2014 2015
	return __rbd_osd_req_create(rbd_dev, snapc, num_ops,
	    (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD) ?
	    CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK : CEPH_OSD_FLAG_READ,
	    obj_request);
A
Alex Elder 已提交
2016 2017
}

2018
/*
2019 2020 2021 2022
 * 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.
2023 2024 2025 2026 2027
 */
static struct ceph_osd_request *
rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
2028
	int num_osd_ops = 3;
2029 2030 2031 2032

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
2033 2034
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
2035

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

2039 2040 2041 2042
	return __rbd_osd_req_create(img_request->rbd_dev,
				    img_request->snapc, num_osd_ops,
				    CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
				    obj_request);
2043 2044
}

A
Alex Elder 已提交
2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

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

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

	rbd_assert(obj_request_type_valid(type));

	size = strlen(object_name) + 1;
2062
	name = kmalloc(size, GFP_NOIO);
2063
	if (!name)
A
Alex Elder 已提交
2064 2065
		return NULL;

2066
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2067 2068 2069 2070 2071
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2072 2073 2074 2075
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2076
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2077 2078
	kref_init(&obj_request->kref);

2079
	dout("%s %p\n", __func__, obj_request);
A
Alex Elder 已提交
2080 2081 2082 2083 2084 2085 2086 2087 2088
	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
2089 2090
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2091 2092 2093 2094 2095 2096 2097 2098
	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) {
2099 2100
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2101 2102 2103 2104
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2105
	case OBJ_REQUEST_PAGES:
2106 2107 2108
		/* img_data requests don't own their page array */
		if (obj_request->pages &&
		    !obj_request_img_data_test(obj_request))
2109 2110 2111
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2112 2113
	}

2114
	kfree(obj_request->object_name);
2115 2116
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2117 2118
}

A
Alex Elder 已提交
2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
/* 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;
}

2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151
/*
 * 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
2152
		rbd_warn(rbd_dev, "parent reference underflow");
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164
}

/*
 * 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)
{
2165
	int counter = 0;
2166 2167 2168 2169

	if (!rbd_dev->parent_spec)
		return false;

2170 2171 2172 2173
	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);
2174 2175

	if (counter < 0)
2176
		rbd_warn(rbd_dev, "parent reference overflow");
2177

2178
	return counter > 0;
2179 2180
}

A
Alex Elder 已提交
2181 2182 2183 2184 2185
/*
 * 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
2186 2187
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2188
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2189
					enum obj_operation_type op_type,
2190
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2191 2192 2193
{
	struct rbd_img_request *img_request;

2194
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2195 2196 2197 2198 2199 2200 2201
	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
2202
	img_request->flags = 0;
2203 2204 2205 2206
	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
2207
		img_request_write_set(img_request);
2208
		img_request->snapc = snapc;
A
Alex Elder 已提交
2209
	} else {
A
Alex Elder 已提交
2210
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2211
	}
2212
	if (rbd_dev_parent_get(rbd_dev))
2213
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2214 2215 2216
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2217
	img_request->result = 0;
A
Alex Elder 已提交
2218 2219 2220 2221
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2222
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2223
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2224

A
Alex Elder 已提交
2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235
	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
2236 2237
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2238 2239
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2240
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2241

2242 2243 2244 2245 2246
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2247 2248
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2249
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2250

2251
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2252 2253
}

2254 2255 2256 2257 2258 2259 2260 2261 2262 2263
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;

2264
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2265
						length, OBJ_OP_READ, NULL);
2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290
	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);
}

2291 2292
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2293
	struct rbd_img_request *img_request;
2294 2295
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2296
	bool more;
2297

2298 2299 2300
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2301 2302 2303 2304 2305
	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
2306 2307
		enum obj_operation_type op_type;

2308 2309 2310 2311 2312 2313
		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;
2314

2315
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2316 2317
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2318
		rbd_warn(rbd_dev, "  result %d xferred %x",
2319 2320 2321
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2322 2323 2324 2325 2326
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2327 2328
	}

A
Alex Elder 已提交
2329 2330 2331 2332 2333
	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
2334 2335 2336 2337

		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
2338 2339 2340
	}

	return more;
2341 2342
}

2343 2344 2345 2346 2347 2348
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;

2349
	rbd_assert(obj_request_img_data_test(obj_request));
2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367
	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;
2368
		more = rbd_img_obj_end_request(obj_request);
2369 2370 2371 2372 2373 2374 2375
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2376
	rbd_img_request_put(img_request);
2377 2378 2379 2380 2381

	if (!more)
		rbd_img_request_complete(img_request);
}

2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400
/*
 * 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) {
2401 2402 2403
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417
			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) {
2418 2419 2420 2421
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2422 2423 2424 2425 2426 2427 2428
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2429
	if (opcode == CEPH_OSD_OP_DELETE)
2430
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2431 2432 2433 2434
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449
	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);
}

2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460
/*
 * 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
2461 2462 2463 2464
{
	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
2465
	struct bio *bio_list = NULL;
2466
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2467
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2468
	enum obj_operation_type op_type;
2469
	u64 img_offset;
A
Alex Elder 已提交
2470 2471
	u64 resid;

2472 2473
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2474

2475
	img_offset = img_request->offset;
A
Alex Elder 已提交
2476
	resid = img_request->length;
A
Alex Elder 已提交
2477
	rbd_assert(resid > 0);
2478
	op_type = rbd_img_request_op_type(img_request);
2479 2480 2481

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2482 2483
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2484
	} else if (type == OBJ_REQUEST_PAGES) {
2485 2486 2487
		pages = data_desc;
	}

A
Alex Elder 已提交
2488
	while (resid) {
2489
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2490
		const char *object_name;
2491 2492
		u64 offset = rbd_segment_offset(rbd_dev, img_offset);
		u64 length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2493

2494
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2495 2496
		if (!object_name)
			goto out_unwind;
2497
		obj_request = rbd_obj_request_create(object_name, type);
2498 2499
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2500 2501
		if (!obj_request)
			goto out_unwind;
2502

2503 2504 2505
		obj_request->offset = offset;
		obj_request->length = length;

2506 2507 2508 2509 2510
		/*
		 * 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
2511

2512 2513 2514 2515 2516 2517 2518 2519 2520
		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,
2521
								GFP_NOIO);
2522
			if (!obj_request->bio_list)
2523
				goto out_unwind;
2524
		} else if (type == OBJ_REQUEST_PAGES) {
2525 2526 2527 2528 2529 2530 2531 2532 2533
			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
2534

G
Guangliang Zhao 已提交
2535 2536 2537
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2538
		if (!osd_req)
2539
			goto out_unwind;
2540

2541
		obj_request->osd_req = osd_req;
2542
		obj_request->callback = rbd_img_obj_callback;
2543
		obj_request->img_offset = img_offset;
2544

2545
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2546

2547
		img_offset += length;
A
Alex Elder 已提交
2548 2549 2550 2551 2552 2553 2554
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2555
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2556 2557 2558 2559

	return -ENOMEM;
}

2560
static void
I
Ilya Dryomov 已提交
2561
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2562 2563 2564
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2565
	struct page **pages;
2566 2567
	u32 page_count;

I
Ilya Dryomov 已提交
2568 2569
	dout("%s: obj %p\n", __func__, obj_request);

2570 2571
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2572 2573 2574 2575 2576 2577 2578
	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);

2579 2580
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2581
	obj_request->copyup_pages = NULL;
2582 2583 2584 2585
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2586 2587 2588 2589 2590 2591 2592 2593 2594 2595

	/*
	 * 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
2596
	obj_request_done_set(obj_request);
2597 2598
}

2599 2600 2601 2602
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2603 2604
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2605
	struct page **pages;
2606
	enum obj_operation_type op_type;
2607
	u32 page_count;
2608
	int img_result;
2609
	u64 parent_length;
2610 2611 2612 2613 2614 2615 2616 2617

	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;
2618 2619 2620
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2621 2622 2623

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2624
	rbd_assert(obj_request_type_valid(orig_request->type));
2625
	img_result = img_request->result;
2626
	parent_length = img_request->length;
2627
	rbd_assert(img_result || parent_length == img_request->xferred);
2628
	rbd_img_request_put(img_request);
2629

2630 2631
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2632 2633
	rbd_assert(rbd_dev);

2634 2635 2636 2637 2638 2639 2640
	/*
	 * 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);
2641 2642
		rbd_obj_request_submit(orig_request);
		return;
2643
	}
2644

2645
	if (img_result)
2646 2647
		goto out_err;

2648 2649
	/*
	 * The original osd request is of no use to use any more.
2650
	 * We need a new one that can hold the three ops in a copyup
2651 2652 2653
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2654
	img_result = -ENOMEM;
2655 2656 2657
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2658
	rbd_osd_req_destroy(orig_request->osd_req);
2659 2660
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2661
	orig_request->copyup_page_count = page_count;
2662

2663
	/* Initialize the copyup op */
2664

2665
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2666
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2667
						false, false);
2668

2669
	/* Add the other op(s) */
2670

2671 2672
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2673 2674 2675

	/* All set, send it off. */

2676 2677
	rbd_obj_request_submit(orig_request);
	return;
2678 2679

out_err:
2680
	ceph_release_page_vector(pages, page_count);
2681
	rbd_obj_request_error(orig_request, img_result);
2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694
}

/*
 * 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.
 *
2695 2696
 * If an error occurs, it is recorded as the result of the original
 * object request in rbd_img_obj_exists_callback().
2697 2698 2699
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
2700
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714
	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
2715
	length = rbd_obj_bytes(&rbd_dev->header);
2716

A
Alex Elder 已提交
2717 2718 2719 2720 2721 2722 2723 2724 2725 2726
	/*
	 * 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;
	}

2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739
	/*
	 * 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;
2740 2741
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2742 2743 2744 2745 2746 2747
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
2748

2749
	parent_request->copyup_pages = pages;
2750
	parent_request->copyup_page_count = page_count;
2751
	parent_request->callback = rbd_img_obj_parent_read_full_callback;
2752

2753 2754 2755 2756 2757
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2758
	parent_request->copyup_page_count = 0;
2759 2760 2761 2762 2763 2764 2765 2766 2767 2768
	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;
}

2769 2770 2771
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2772
	struct rbd_device *rbd_dev;
2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783
	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;
2784
	rbd_obj_request_put(orig_request);
2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795
	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);

2796 2797
	/*
	 * If the overlap has become 0 (most likely because the
2798 2799
	 * image has been flattened) we need to re-submit the
	 * original request.
2800 2801 2802
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2803 2804
		rbd_obj_request_submit(orig_request);
		return;
2805
	}
2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816

	/*
	 * 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);
2817 2818
	} else {
		goto fail_orig_request;
2819 2820 2821 2822 2823 2824
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2825 2826 2827 2828 2829 2830 2831
	result = rbd_img_obj_request_submit(orig_request);
	if (result)
		goto fail_orig_request;

	return;

fail_orig_request:
2832
	rbd_obj_request_error(orig_request, result);
2833 2834 2835 2836
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
2837
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2838
	struct rbd_obj_request *stat_request;
2839
	struct page **pages;
2840 2841 2842 2843
	u32 page_count;
	size_t size;
	int ret;

2844
	stat_request = rbd_obj_request_create(obj_request->object_name,
2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855
					      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;
	}

2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866
	/*
	 * 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);
2867 2868 2869 2870
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto fail_stat_request;
	}
2871

2872 2873 2874
	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);
2875 2876 2877 2878 2879 2880 2881

	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;

2882 2883
	rbd_obj_request_submit(stat_request);
	return 0;
2884

2885 2886
fail_stat_request:
	rbd_obj_request_put(stat_request);
2887 2888 2889
	return ret;
}

2890
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2891
{
2892 2893
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
2894

2895
	/* Reads */
2896 2897
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2898 2899 2900 2901 2902 2903
		return true;

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

2904
	/*
2905 2906
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2907
	 */
2908 2909
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2910

2911 2912 2913 2914 2915 2916 2917 2918
	/*
	 * 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;

2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931
	/*
	 * 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)
{
2932 2933 2934
	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request_type_valid(obj_request->type));
	rbd_assert(obj_request->img_request);
2935

2936
	if (img_obj_request_simple(obj_request)) {
2937 2938
		rbd_obj_request_submit(obj_request);
		return 0;
2939 2940 2941
	}

	/*
2942 2943 2944 2945
	 * 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.
2946
	 */
2947
	if (obj_request_known_test(obj_request))
2948 2949 2950
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
2951 2952 2953 2954

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
2955 2956 2957
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
2958
	struct rbd_obj_request *next_obj_request;
2959
	int ret = 0;
A
Alex Elder 已提交
2960

A
Alex Elder 已提交
2961
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
2962

2963 2964
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2965
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
2966
		if (ret)
2967
			goto out_put_ireq;
A
Alex Elder 已提交
2968 2969
	}

2970 2971 2972
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
2973
}
A
Alex Elder 已提交
2974 2975 2976 2977

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
2978 2979
	struct rbd_device *rbd_dev;
	u64 obj_end;
2980 2981
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
2982 2983 2984

	rbd_assert(img_request_child_test(img_request));

2985 2986
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
2987
	obj_request = img_request->obj_request;
2988 2989 2990 2991 2992 2993 2994 2995 2996
	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
2997 2998
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
2999 3000
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
3001 3002
		rbd_obj_request_submit(obj_request);
		return;
3003
	}
A
Alex Elder 已提交
3004

3005
	obj_request->result = img_result;
A
Alex Elder 已提交
3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023
	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
3024

3025
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
3026
	} else {
3027
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
3028 3029
	}
out:
A
Alex Elder 已提交
3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041
	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);
3042
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3043 3044

	/* rbd_read_finish(obj_request, obj_request->length); */
3045
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
3046
						obj_request->img_offset,
3047
						obj_request->length);
A
Alex Elder 已提交
3048 3049 3050 3051
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

3052 3053 3054 3055 3056 3057
	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
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073
	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
3074

3075
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
3076

3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116
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
3117
{
3118
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3119 3120
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
	char cookie[32];
3121
	int ret;
A
Alex Elder 已提交
3122

3123
	WARN_ON(__rbd_is_lock_owner(rbd_dev));
3124

3125 3126 3127 3128
	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);
3129
	if (ret)
3130
		return ret;
A
Alex Elder 已提交
3131

3132 3133 3134 3135
	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
3136 3137
}

3138 3139 3140 3141
/*
 * lock_rwsem must be held for write
 */
static int rbd_unlock(struct rbd_device *rbd_dev)
3142
{
3143
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3144
	char cookie[32];
3145 3146
	int ret;

3147
	WARN_ON(!__rbd_is_lock_owner(rbd_dev));
3148

3149
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3150

3151 3152 3153 3154 3155 3156
	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;
3157 3158
	}

3159 3160 3161
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
	return 0;
3162 3163
}

3164 3165 3166 3167
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)
3168 3169
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3170 3171 3172 3173
	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;
3174

3175
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3176

3177 3178 3179 3180 3181
	/* 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);
3182

3183 3184 3185
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3186 3187
}

3188 3189
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
3190
{
3191 3192
	struct page **reply_pages;
	size_t reply_len;
3193

3194 3195 3196
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
3197

3198 3199 3200 3201
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
3202

3203
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3204 3205
}

3206
static void rbd_notify_released_lock(struct work_struct *work)
3207
{
3208 3209
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
3210

3211
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3212 3213
}

3214
static int rbd_request_lock(struct rbd_device *rbd_dev)
3215
{
3216 3217 3218
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
3219 3220
	int ret;

3221
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3222

3223 3224 3225 3226
	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);
3227
		goto out;
3228
	}
3229

3230 3231 3232 3233
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
3234

3235 3236 3237 3238
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
3239

3240 3241
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
3242

3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 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
			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);
3519
	/*
3520
	 * Ensure that all in-flight IO is flushed.
3521
	 *
3522 3523
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3524
	 */
3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671
	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
3672

3673 3674
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3675
				   buf, buf_size);
3676
	if (ret)
3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699
		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;
3700
	u8 struct_v = 0;
3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758
	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
3759 3760
}

3761 3762
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3763
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3764
{
3765
	struct rbd_device *rbd_dev = arg;
3766

3767
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3768

3769 3770 3771 3772
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3773 3774 3775 3776
	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;
3777

3778
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3779
	}
3780
	mutex_unlock(&rbd_dev->watch_mutex);
3781 3782
}

3783
/*
3784
 * watch_mutex must be locked
3785
 */
3786
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3787 3788
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3789
	struct ceph_osd_linger_request *handle;
3790

3791
	rbd_assert(!rbd_dev->watch_handle);
3792
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3793

3794 3795 3796 3797 3798
	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);
3799

3800
	rbd_dev->watch_handle = handle;
3801 3802 3803
	return 0;
}

3804 3805 3806 3807
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3808
{
3809 3810
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3811

3812 3813
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3814

3815 3816 3817
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3818

3819
	rbd_dev->watch_handle = NULL;
3820 3821
}

3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840
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)
3841
{
3842 3843 3844
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3845 3846 3847 3848
	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);
3849 3850 3851 3852
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3853
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3854 3855 3856 3857 3858 3859 3860
	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
3861 3862

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3863 3864
}

3865 3866 3867 3868
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);
3869
	bool was_lock_owner = false;
3870
	bool need_to_wake = false;
3871 3872 3873 3874
	int ret;

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

3875 3876 3877 3878
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		was_lock_owner = rbd_release_lock(rbd_dev);

3879
	mutex_lock(&rbd_dev->watch_mutex);
3880 3881 3882 3883
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
	}
3884 3885 3886 3887

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3888
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3889 3890 3891
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
			need_to_wake = true;
		} else {
3892 3893 3894
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3895 3896 3897
		}
		mutex_unlock(&rbd_dev->watch_mutex);
		goto out;
3898 3899
	}

3900
	need_to_wake = true;
3901 3902 3903 3904 3905 3906 3907 3908
	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);

3909 3910 3911 3912 3913 3914 3915
	if (was_lock_owner) {
		ret = rbd_try_lock(rbd_dev);
		if (ret)
			rbd_warn(rbd_dev, "reregisteration lock failed: %d",
				 ret);
	}

3916
out:
3917
	up_write(&rbd_dev->lock_rwsem);
3918 3919
	if (need_to_wake)
		wake_requests(rbd_dev, true);
3920 3921
}

3922
/*
3923 3924
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3925 3926
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3927 3928
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3929
			     const char *method_name,
3930
			     const void *outbound,
3931
			     size_t outbound_size,
3932
			     void *inbound,
3933
			     size_t inbound_size)
3934
{
3935 3936 3937
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3938 3939 3940
	int ret;

	/*
3941 3942 3943 3944 3945
	 * 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.
3946
	 */
3947 3948 3949
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3950

3951 3952 3953
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3954

3955
		memcpy(page_address(req_page), outbound, outbound_size);
3956
	}
A
Alex Elder 已提交
3957

3958 3959 3960 3961 3962 3963
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3964

3965 3966 3967 3968 3969 3970 3971
	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;
	}
3972

3973 3974 3975
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
3976 3977 3978
	return ret;
}

3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997
/*
 * 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);
3998 3999 4000
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

4001 4002 4003
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
4004
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
4005
{
C
Christoph Hellwig 已提交
4006 4007
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
4008
	struct rbd_img_request *img_request;
4009
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
4010 4011
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
4012
	enum obj_operation_type op_type;
4013
	u64 mapping_size;
I
Ilya Dryomov 已提交
4014
	bool must_be_locked;
A
Alex Elder 已提交
4015 4016
	int result;

C
Christoph Hellwig 已提交
4017 4018 4019 4020 4021 4022 4023
	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
4024
	if (req_op(rq) == REQ_OP_DISCARD)
4025
		op_type = OBJ_OP_DISCARD;
M
Mike Christie 已提交
4026
	else if (req_op(rq) == REQ_OP_WRITE)
G
Guangliang Zhao 已提交
4027 4028 4029 4030
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
4031
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4032

I
Ilya Dryomov 已提交
4033 4034 4035 4036 4037
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4038

G
Guangliang Zhao 已提交
4039
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
4040

G
Guangliang Zhao 已提交
4041
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
4042 4043 4044
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
4045
		}
I
Ilya Dryomov 已提交
4046 4047
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
4048

I
Ilya Dryomov 已提交
4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060
	/*
	 * 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
4061

I
Ilya Dryomov 已提交
4062 4063 4064 4065 4066 4067
	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
4068

C
Christoph Hellwig 已提交
4069 4070
	blk_mq_start_request(rq);

4071 4072
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4073
	if (op_type != OBJ_OP_READ) {
4074 4075
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
4076
		must_be_locked = rbd_is_lock_supported(rbd_dev);
I
Ilya Dryomov 已提交
4077 4078 4079
	} else {
		must_be_locked = rbd_dev->opts->lock_on_read &&
					rbd_is_lock_supported(rbd_dev);
4080 4081 4082 4083
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4084
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4085
			 length, mapping_size);
I
Ilya Dryomov 已提交
4086 4087 4088
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4089

4090 4091
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
4092 4093
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
4094
			rbd_wait_state_locked(rbd_dev);
4095 4096 4097 4098 4099 4100 4101

		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;
		}
4102 4103
	}

G
Guangliang Zhao 已提交
4104
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4105
					     snapc);
I
Ilya Dryomov 已提交
4106 4107
	if (!img_request) {
		result = -ENOMEM;
4108
		goto err_unlock;
I
Ilya Dryomov 已提交
4109 4110
	}
	img_request->rq = rq;
4111
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4112

4113 4114 4115 4116 4117 4118
	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
4119 4120
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4121

I
Ilya Dryomov 已提交
4122 4123 4124
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4125

4126 4127
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4128
	return;
A
Alex Elder 已提交
4129

I
Ilya Dryomov 已提交
4130 4131
err_img_request:
	rbd_img_request_put(img_request);
4132 4133 4134
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4135 4136 4137
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4138
			 obj_op_name(op_type), length, offset, result);
4139
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4140 4141
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
4142
}
A
Alex Elder 已提交
4143

C
Christoph Hellwig 已提交
4144 4145
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4146
{
C
Christoph Hellwig 已提交
4147 4148
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4149

C
Christoph Hellwig 已提交
4150 4151
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
4152 4153
}

4154 4155 4156 4157 4158 4159 4160
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

4161 4162
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
4163
		del_gendisk(disk);
4164 4165
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
4166
		blk_mq_free_tag_set(&rbd_dev->tag_set);
4167
	}
4168 4169 4170
	put_disk(disk);
}

4171
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4172 4173 4174
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
4175 4176

{
4177 4178 4179 4180
	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);
4181 4182
	int ret;

4183 4184 4185
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
4186

4187 4188 4189
	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
4190

4191
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
4192
	if (ret)
4193
		goto out_req;
4194

4195 4196 4197 4198 4199
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
4200

4201 4202 4203 4204 4205 4206 4207 4208
	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);
4209

4210 4211
out_req:
	ceph_osdc_put_request(req);
4212 4213 4214
	return ret;
}

4215
/*
A
Alex Elder 已提交
4216 4217 4218
 * 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.
4219
 */
4220
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4221
{
4222
	struct rbd_image_header_ondisk *ondisk = NULL;
4223
	u32 snap_count = 0;
4224 4225 4226
	u64 names_size = 0;
	u32 want_count;
	int ret;
4227

A
Alex Elder 已提交
4228
	/*
4229 4230 4231 4232 4233
	 * 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
4234
	 */
4235 4236 4237 4238 4239 4240 4241 4242 4243 4244
	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
4245
			return -ENOMEM;
4246

4247 4248
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
4249
		if (ret < 0)
A
Alex Elder 已提交
4250
			goto out;
A
Alex Elder 已提交
4251
		if ((size_t)ret < size) {
4252
			ret = -ENXIO;
A
Alex Elder 已提交
4253 4254
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4255
			goto out;
4256 4257 4258
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4259
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4260
			goto out;
4261
		}
4262

4263 4264 4265 4266
		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
4267

A
Alex Elder 已提交
4268 4269
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4270 4271 4272
	kfree(ondisk);

	return ret;
4273 4274
}

4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293
/*
 * 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);
}

4294 4295 4296 4297 4298
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4299 4300 4301
	 * 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.
4302
	 */
I
Ilya Dryomov 已提交
4303 4304
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4305 4306 4307 4308 4309 4310 4311
		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
4312
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4313
{
4314
	u64 mapping_size;
A
Alex Elder 已提交
4315 4316
	int ret;

4317
	down_write(&rbd_dev->header_rwsem);
4318
	mapping_size = rbd_dev->mapping.size;
4319 4320

	ret = rbd_dev_header_info(rbd_dev);
4321
	if (ret)
4322
		goto out;
4323

4324 4325 4326 4327 4328 4329 4330
	/*
	 * 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)
4331
			goto out;
4332 4333
	}

4334
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4335
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4336 4337 4338 4339
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4340

4341
out:
4342
	up_write(&rbd_dev->header_rwsem);
4343
	if (!ret && mapping_size != rbd_dev->mapping.size)
4344
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4345

4346
	return ret;
A
Alex Elder 已提交
4347 4348
}

C
Christoph Hellwig 已提交
4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363
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,
};

4364 4365 4366 4367
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4368
	u64 segment_size;
C
Christoph Hellwig 已提交
4369
	int err;
4370 4371

	/* create gendisk info */
4372 4373 4374
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4375
	if (!disk)
A
Alex Elder 已提交
4376
		return -ENOMEM;
4377

A
Alex Elder 已提交
4378
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4379
		 rbd_dev->dev_id);
4380
	disk->major = rbd_dev->major;
4381
	disk->first_minor = rbd_dev->minor;
4382 4383
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4384 4385 4386
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4387 4388
	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
4389
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4390
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4391
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4392 4393 4394 4395 4396
	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)
4397
		goto out_disk;
4398

C
Christoph Hellwig 已提交
4399 4400 4401 4402 4403 4404
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4405 4406
	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
4407

4408
	/* set io sizes to object size */
A
Alex Elder 已提交
4409 4410
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4411
	q->limits.max_sectors = queue_max_hw_sectors(q);
I
Ilya Dryomov 已提交
4412
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
4413 4414 4415
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4416

4417 4418 4419 4420
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
4421
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4422
	q->limits.discard_zeroes_data = 1;
4423

4424 4425 4426
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
		q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

4427 4428 4429 4430 4431 4432 4433
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4434 4435
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4436 4437
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4438
	return err;
4439 4440
}

4441 4442 4443 4444
/*
  sysfs
*/

A
Alex Elder 已提交
4445 4446 4447 4448 4449
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4450 4451 4452
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4453
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4454

A
Alex Elder 已提交
4455 4456
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4457 4458
}

A
Alex Elder 已提交
4459 4460 4461 4462 4463 4464 4465 4466 4467 4468
/*
 * 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
4469
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4470 4471
}

4472 4473 4474
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4475
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4476

A
Alex Elder 已提交
4477 4478 4479 4480
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4481 4482 4483 4484 4485 4486
}

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
4487

4488
	return sprintf(buf, "%d\n", rbd_dev->minor);
4489 4490
}

4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501
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));
}

4502 4503
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4504
{
A
Alex Elder 已提交
4505
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4506

4507
	return sprintf(buf, "client%lld\n",
4508
		       ceph_client_gid(rbd_dev->rbd_client->client));
4509 4510
}

4511 4512 4513 4514 4515 4516 4517 4518
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);
}

4519 4520 4521 4522 4523 4524
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);
4525 4526
}

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

4532
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4533 4534
}

4535 4536 4537 4538 4539
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);

4540
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4541
			(unsigned long long) rbd_dev->spec->pool_id);
4542 4543
}

4544 4545 4546
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4547
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4548

A
Alex Elder 已提交
4549 4550 4551 4552
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4553 4554
}

A
Alex Elder 已提交
4555 4556 4557 4558 4559
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);

4560
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4561 4562
}

A
Alex Elder 已提交
4563 4564 4565 4566
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4567 4568 4569 4570
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4571
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4572

4573
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4574 4575
}

4576 4577 4578 4579 4580 4581 4582 4583
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);
}

4584
/*
4585 4586 4587
 * 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)".
4588 4589
 */
static ssize_t rbd_parent_show(struct device *dev,
4590 4591
			       struct device_attribute *attr,
			       char *buf)
4592 4593
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4594
	ssize_t count = 0;
4595

4596
	if (!rbd_dev->parent)
4597 4598
		return sprintf(buf, "(no parent image)\n");

4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614
	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;
4615 4616
}

4617 4618 4619 4620 4621
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
4622
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4623
	int ret;
4624

A
Alex Elder 已提交
4625
	ret = rbd_dev_refresh(rbd_dev);
4626
	if (ret)
4627
		return ret;
4628

4629
	return size;
4630
}
4631

4632
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4633
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4634
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4635
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4636
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4637
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4638
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4639
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4640
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4641
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4642
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4643
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4644 4645
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4646
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4647
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4648 4649 4650

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4651
	&dev_attr_features.attr,
4652
	&dev_attr_major.attr,
4653
	&dev_attr_minor.attr,
4654
	&dev_attr_client_addr.attr,
4655
	&dev_attr_client_id.attr,
4656
	&dev_attr_cluster_fsid.attr,
4657
	&dev_attr_config_info.attr,
4658
	&dev_attr_pool.attr,
4659
	&dev_attr_pool_id.attr,
4660
	&dev_attr_name.attr,
A
Alex Elder 已提交
4661
	&dev_attr_image_id.attr,
4662
	&dev_attr_current_snap.attr,
4663
	&dev_attr_snap_id.attr,
4664
	&dev_attr_parent.attr,
4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677
	&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
};

4678
static void rbd_dev_release(struct device *dev);
4679 4680 4681 4682

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4683
	.release	= rbd_dev_release,
4684 4685
};

4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706
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;
4707 4708 4709

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725
	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);
}

4726
static void rbd_dev_free(struct rbd_device *rbd_dev)
4727
{
4728
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4729
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4730

4731
	ceph_oid_destroy(&rbd_dev->header_oid);
4732
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4733
	kfree(rbd_dev->config_info);
4734

4735 4736 4737 4738
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751
}

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);
4752 4753 4754 4755 4756 4757 4758 4759 4760 4761

	/*
	 * 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);
}

4762 4763
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4764 4765 4766
{
	struct rbd_device *rbd_dev;

4767
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4768 4769 4770 4771 4772 4773 4774
	if (!rbd_dev)
		return NULL;

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

4775
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4776
	ceph_oid_init(&rbd_dev->header_oid);
4777
	rbd_dev->header_oloc.pool = spec->pool_id;
4778

4779 4780 4781 4782
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4783 4784 4785 4786 4787 4788 4789 4790
	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);

4791 4792 4793 4794 4795
	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);

4796
	rbd_dev->rbd_client = rbdc;
4797
	rbd_dev->spec = spec;
4798

4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828
	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;
4829

4830 4831
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4832

4833
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4834
	return rbd_dev;
4835 4836 4837 4838 4839 4840

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4841 4842 4843 4844
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4845 4846
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4847 4848
}

4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863
/*
 * 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 };

4864 4865 4866 4867
	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));
4868
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4869 4870
	if (ret < 0)
		return ret;
4871 4872
	if (ret < sizeof (size_buf))
		return -ERANGE;
4873

J
Josh Durgin 已提交
4874
	if (order) {
4875
		*order = size_buf.order;
J
Josh Durgin 已提交
4876 4877
		dout("  order %u", (unsigned int)*order);
	}
4878 4879
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4880 4881
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4882
		(unsigned long long)*snap_size);
4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893

	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);
}

4894 4895 4896 4897 4898 4899 4900 4901 4902 4903
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;

4904 4905 4906
	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);
4907
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4908 4909 4910 4911 4912
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4913 4914
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927

	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;
}

4928 4929 4930 4931 4932 4933 4934
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;
4935
	} __attribute__ ((packed)) features_buf = { 0 };
4936
	u64 unsup;
4937 4938
	int ret;

4939 4940 4941 4942
	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));
4943
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4944 4945
	if (ret < 0)
		return ret;
4946 4947
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4948

4949 4950 4951 4952
	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
4953
		return -ENXIO;
4954
	}
A
Alex Elder 已提交
4955

4956 4957 4958
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4959 4960 4961
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4962 4963 4964 4965 4966 4967 4968 4969 4970 4971

	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);
}

4972 4973 4974 4975 4976 4977 4978 4979
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
4980
	u64 pool_id;
4981
	char *image_id;
4982
	u64 snap_id;
4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999
	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;
	}

5000
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5001 5002 5003
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
5004
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5005 5006 5007 5008
	if (ret < 0)
		goto out_err;

	p = reply_buf;
5009 5010
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
5011
	ceph_decode_64_safe(&p, end, pool_id, out_err);
5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028
	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);
		}

5029
		goto out;	/* No parent?  No problem. */
5030
	}
5031

5032 5033 5034
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5035
	if (pool_id > (u64)U32_MAX) {
5036
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5037
			(unsigned long long)pool_id, U32_MAX);
5038
		goto out_err;
A
Alex Elder 已提交
5039
	}
5040

A
Alex Elder 已提交
5041
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5042 5043 5044 5045
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5046
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5047 5048
	ceph_decode_64_safe(&p, end, overlap, out_err);

5049 5050 5051 5052 5053 5054 5055 5056 5057
	/*
	 * 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
5058 5059
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5060 5061
	} else {
		kfree(image_id);
5062 5063 5064
	}

	/*
5065 5066
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5067 5068 5069
	 */
	if (!overlap) {
		if (parent_spec) {
5070 5071 5072 5073
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5074
		} else {
5075 5076
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5077
		}
A
Alex Elder 已提交
5078
	}
5079 5080
	rbd_dev->parent_overlap = overlap;

5081 5082 5083 5084 5085 5086 5087 5088 5089
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102
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;

5103 5104 5105
	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);
5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117 5118
	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
5119
	obj_size = rbd_obj_bytes(&rbd_dev->header);
5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133
	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;
	}
5134 5135
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5136 5137 5138 5139

	return 0;
}

5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157
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;
}

5158 5159
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
5160
	CEPH_DEFINE_OID_ONSTACK(oid);
5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172
	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
5173 5174
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5175 5176 5177 5178 5179
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5180
	end = image_id + image_id_size;
5181
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5182 5183 5184 5185 5186 5187

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

5188 5189 5190 5191
	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);
5192 5193 5194
	if (ret < 0)
		goto out;
	p = reply_buf;
5195 5196
	end = reply_buf + ret;

5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208
	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;
}

5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238
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);
5239 5240 5241 5242 5243 5244 5245
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263
		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);
}

5264
/*
5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291
 * 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.
5292
 *
5293 5294
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5295
 */
5296
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5297
{
5298 5299 5300 5301 5302
	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;
5303 5304
	int ret;

5305 5306 5307
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5308

5309
	/* Get the pool name; we have to make our own copy of this */
5310

5311 5312 5313
	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);
5314 5315
		return -EIO;
	}
5316 5317
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5318 5319 5320 5321
		return -ENOMEM;

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

5322 5323
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5324
		rbd_warn(rbd_dev, "unable to get image name");
5325

5326
	/* Fetch the snapshot name */
5327

5328
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5329 5330
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5331
		goto out_err;
5332 5333 5334 5335 5336
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5337 5338

	return 0;
5339

5340
out_err:
5341 5342
	kfree(image_name);
	kfree(pool_name);
5343 5344 5345
	return ret;
}

A
Alex Elder 已提交
5346
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369
{
	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;

5370 5371 5372
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
5373
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5374 5375 5376 5377
	if (ret < 0)
		goto out;

	p = reply_buf;
5378 5379
	end = reply_buf + ret;
	ret = -ERANGE;
5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395
	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;
5396
	ret = 0;
5397

5398
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5399 5400 5401 5402 5403 5404 5405 5406
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5407
	ceph_put_snap_context(rbd_dev->header.snapc);
5408 5409 5410
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5411
		(unsigned long long)seq, (unsigned int)snap_count);
5412 5413 5414
out:
	kfree(reply_buf);

5415
	return ret;
5416 5417
}

5418 5419
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5420 5421 5422
{
	size_t size;
	void *reply_buf;
5423
	__le64 snapid;
A
Alex Elder 已提交
5424 5425 5426 5427 5428 5429 5430 5431 5432 5433
	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);

5434
	snapid = cpu_to_le64(snap_id);
5435 5436 5437
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
5438
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5439 5440
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5441
		goto out;
5442
	}
A
Alex Elder 已提交
5443 5444

	p = reply_buf;
5445
	end = reply_buf + ret;
A
Alex Elder 已提交
5446
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5447
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5448 5449
		goto out;

5450
	dout("  snap_id 0x%016llx snap_name = %s\n",
5451
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5452 5453 5454
out:
	kfree(reply_buf);

5455
	return snap_name;
A
Alex Elder 已提交
5456 5457
}

5458
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5459
{
5460
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5461 5462
	int ret;

5463 5464
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5465
		return ret;
5466

5467 5468 5469
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5470
			return ret;
5471 5472
	}

A
Alex Elder 已提交
5473
	ret = rbd_dev_v2_snap_context(rbd_dev);
5474 5475 5476 5477
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5478 5479 5480 5481

	return ret;
}

5482 5483 5484 5485 5486 5487 5488 5489 5490 5491
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);
}

5492 5493 5494
/*
 * 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
5495 5496
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5497 5498 5499 5500 5501 5502 5503 5504 5505 5506 5507 5508 5509 5510
 */
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
5511 5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532
/*
 * 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
5533
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5545
/*
5546 5547 5548 5549
 * 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
5550
 *
5551 5552 5553 5554 5555 5556 5557 5558 5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584
 * 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.
5585
 */
5586
static int rbd_add_parse_args(const char *buf,
5587
				struct ceph_options **ceph_opts,
5588 5589
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5590
{
A
Alex Elder 已提交
5591
	size_t len;
5592
	char *options;
5593
	const char *mon_addrs;
5594
	char *snap_name;
5595
	size_t mon_addrs_size;
5596
	struct rbd_spec *spec = NULL;
5597
	struct rbd_options *rbd_opts = NULL;
5598
	struct ceph_options *copts;
5599
	int ret;
5600 5601 5602

	/* The first four tokens are required */

5603
	len = next_token(&buf);
5604 5605 5606 5607
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5608
	mon_addrs = buf;
5609
	mon_addrs_size = len + 1;
5610
	buf += len;
5611

5612
	ret = -EINVAL;
5613 5614
	options = dup_token(&buf, NULL);
	if (!options)
5615
		return -ENOMEM;
5616 5617 5618 5619
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5620

5621 5622
	spec = rbd_spec_alloc();
	if (!spec)
5623
		goto out_mem;
5624 5625 5626 5627

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5628 5629 5630 5631
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5632

A
Alex Elder 已提交
5633
	spec->image_name = dup_token(&buf, NULL);
5634
	if (!spec->image_name)
5635
		goto out_mem;
5636 5637 5638 5639
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5640

5641 5642 5643 5644
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5645
	len = next_token(&buf);
5646
	if (!len) {
5647 5648
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5649
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5650
		ret = -ENAMETOOLONG;
5651
		goto out_err;
5652
	}
5653 5654
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5655
		goto out_mem;
5656 5657
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5658

5659
	/* Initialize all rbd options to the defaults */
5660

5661 5662 5663 5664 5665
	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
5666
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5667
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
A
Alex Elder 已提交
5668

5669
	copts = ceph_parse_options(options, mon_addrs,
5670
					mon_addrs + mon_addrs_size - 1,
5671
					parse_rbd_opts_token, rbd_opts);
5672 5673
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5674 5675
		goto out_err;
	}
5676 5677 5678
	kfree(options);

	*ceph_opts = copts;
5679
	*opts = rbd_opts;
5680
	*rbd_spec = spec;
5681

5682
	return 0;
5683
out_mem:
5684
	ret = -ENOMEM;
A
Alex Elder 已提交
5685
out_err:
5686 5687
	kfree(rbd_opts);
	rbd_spec_put(spec);
5688
	kfree(options);
A
Alex Elder 已提交
5689

5690
	return ret;
5691 5692
}

5693 5694 5695 5696 5697
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5698
	struct ceph_options *opts = rbdc->client->options;
5699 5700 5701 5702 5703 5704 5705
	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) {
5706 5707
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5708 5709 5710 5711
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5712
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5713
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5714 5715
						     newest_epoch,
						     opts->mount_timeout);
5716 5717 5718 5719 5720 5721 5722 5723 5724 5725
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743
/*
 * 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;
5744
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5745
	void *response;
5746
	char *image_id;
5747

A
Alex Elder 已提交
5748 5749 5750
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5751 5752
	 * 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
5753
	 */
5754 5755 5756
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5757
		return 0;
5758
	}
A
Alex Elder 已提交
5759

A
Alex Elder 已提交
5760 5761 5762 5763
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5764 5765 5766 5767 5768 5769
	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
5770 5771 5772 5773 5774 5775 5776 5777 5778 5779

	/* 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;
	}

5780 5781
	/* If it doesn't exist we'll assume it's a format 1 image */

5782 5783 5784
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5785
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5786 5787 5788 5789 5790
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5791
	} else if (ret >= 0) {
5792 5793 5794
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5795
						NULL, GFP_NOIO);
5796
		ret = PTR_ERR_OR_ZERO(image_id);
5797 5798 5799 5800 5801 5802 5803
		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
5804 5805 5806
	}
out:
	kfree(response);
5807
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5808 5809 5810
	return ret;
}

A
Alex Elder 已提交
5811 5812 5813 5814
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5815 5816 5817 5818
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5819
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5820 5821 5822 5823

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

	header = &rbd_dev->header;
5824
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5825 5826 5827 5828 5829 5830
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5831
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5832 5833 5834
{
	int ret;

5835
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5836
	if (ret)
5837 5838
		goto out_err;

5839 5840 5841 5842
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5843
	ret = rbd_dev_v2_features(rbd_dev);
5844
	if (ret)
5845
		goto out_err;
5846

5847 5848 5849 5850 5851 5852 5853
	/* 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;
	}
5854

5855 5856 5857 5858 5859 5860
	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
5861
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5862
	return 0;
I
Ilya Dryomov 已提交
5863

5864
out_err:
A
Alex Elder 已提交
5865
	rbd_dev->header.features = 0;
5866 5867
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5868
	return ret;
5869 5870
}

5871 5872 5873 5874 5875 5876
/*
 * @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
5877
{
5878
	struct rbd_device *parent = NULL;
5879 5880 5881 5882 5883
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5884 5885 5886 5887 5888 5889
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5890
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5891 5892
	if (!parent) {
		ret = -ENOMEM;
5893
		goto out_err;
5894 5895 5896 5897 5898 5899 5900 5901
	}

	/*
	 * 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);
5902

5903
	ret = rbd_dev_image_probe(parent, depth);
5904 5905
	if (ret < 0)
		goto out_err;
5906

5907
	rbd_dev->parent = parent;
5908
	atomic_set(&rbd_dev->parent_ref, 1);
5909
	return 0;
5910

5911
out_err:
5912
	rbd_dev_unparent(rbd_dev);
5913
	rbd_dev_destroy(parent);
5914 5915 5916
	return ret;
}

I
Ilya Dryomov 已提交
5917 5918 5919 5920
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5921
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5922
{
A
Alex Elder 已提交
5923
	int ret;
A
Alex Elder 已提交
5924

5925
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5926

5927 5928 5929
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5930
			goto err_out_unlock;
5931 5932 5933 5934 5935 5936 5937

		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
5938 5939 5940 5941 5942 5943 5944

	/* Set up the blkdev mapping. */

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

5945
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5946 5947
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5948

5949
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5950
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
5951

5952 5953
	dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
	ret = device_add(&rbd_dev->dev);
5954
	if (ret)
5955
		goto err_out_mapping;
A
Alex Elder 已提交
5956 5957 5958

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

5959
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5960
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5961

5962 5963 5964 5965
	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
5966
	add_disk(rbd_dev->disk);
5967 5968 5969
	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
5970 5971

	return ret;
5972

5973 5974
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5975 5976 5977
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5978 5979
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
5980 5981
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5982 5983 5984
	return ret;
}

A
Alex Elder 已提交
5985 5986 5987
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
5988
	int ret;
A
Alex Elder 已提交
5989 5990 5991 5992 5993

	/* 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)
5994 5995
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
5996
	else
5997 5998
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
5999

6000
	return ret;
A
Alex Elder 已提交
6001 6002
}

6003 6004
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6005 6006 6007 6008 6009
	rbd_dev_unprobe(rbd_dev);
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

6010 6011 6012
	rbd_dev_destroy(rbd_dev);
}

6013 6014
/*
 * Probe for the existence of the header object for the given rbd
6015 6016 6017
 * 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.
6018
 */
6019
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6020 6021 6022 6023
{
	int ret;

	/*
A
Alex Elder 已提交
6024 6025 6026 6027
	 * 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.
6028 6029 6030
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6031 6032
		return ret;

A
Alex Elder 已提交
6033 6034 6035 6036
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6037
	if (!depth) {
6038
		ret = rbd_register_watch(rbd_dev);
6039 6040 6041 6042 6043
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6044
			goto err_out_format;
6045
		}
6046
	}
6047

6048
	ret = rbd_dev_header_info(rbd_dev);
6049
	if (ret)
6050
		goto err_out_watch;
A
Alex Elder 已提交
6051

6052 6053 6054 6055 6056 6057
	/*
	 * 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.
	 */
6058
	if (!depth)
6059 6060 6061
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6062 6063 6064 6065 6066 6067
	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
6068
		goto err_out_probe;
6069
	}
6070

6071 6072 6073 6074 6075 6076 6077 6078 6079
	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.
		 */
6080
		if (!depth && rbd_dev->parent_spec)
6081 6082 6083 6084
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6085
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6086 6087 6088 6089
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6090
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6091
	return 0;
6092

A
Alex Elder 已提交
6093 6094
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6095
err_out_watch:
6096
	if (!depth)
6097
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6098 6099
err_out_format:
	rbd_dev->image_format = 0;
6100 6101
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6102 6103 6104
	return ret;
}

6105 6106 6107
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6108
{
6109
	struct rbd_device *rbd_dev = NULL;
6110
	struct ceph_options *ceph_opts = NULL;
6111
	struct rbd_options *rbd_opts = NULL;
6112
	struct rbd_spec *spec = NULL;
6113
	struct rbd_client *rbdc;
6114
	bool read_only;
6115
	int rc;
6116 6117 6118 6119 6120

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

	/* parse add command */
6121
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6122
	if (rc < 0)
6123
		goto out;
6124

6125 6126 6127
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6128
		goto err_out_args;
6129
	}
6130 6131

	/* pick the pool */
6132
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6133 6134 6135
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6136
		goto err_out_client;
6137
	}
A
Alex Elder 已提交
6138
	spec->pool_id = (u64)rc;
6139

6140
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6141 6142
	if (!rbd_dev) {
		rc = -ENOMEM;
6143
		goto err_out_client;
6144
	}
6145 6146
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6147
	rbd_opts = NULL;	/* rbd_dev now owns this */
6148

6149 6150 6151 6152 6153 6154
	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
6155
	down_write(&rbd_dev->header_rwsem);
6156
	rc = rbd_dev_image_probe(rbd_dev, 0);
6157 6158
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6159
		goto err_out_rbd_dev;
6160
	}
6161

6162 6163
	/* If we are mapping a snapshot it must be marked read-only */

6164
	read_only = rbd_dev->opts->read_only;
6165 6166 6167 6168
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

6169
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
6170
	if (rc) {
6171
		/*
6172
		 * rbd_unregister_watch() can't be moved into
6173 6174 6175
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
6176
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6177
		rbd_dev_image_release(rbd_dev);
6178
		goto out;
A
Alex Elder 已提交
6179 6180
	}

6181 6182 6183 6184
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6185

6186 6187
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6188
err_out_client:
6189
	rbd_put_client(rbdc);
6190
err_out_args:
6191
	rbd_spec_put(spec);
6192
	kfree(rbd_opts);
6193
	goto out;
6194 6195
}

6196 6197 6198 6199 6200 6201 6202 6203 6204 6205 6206 6207 6208 6209 6210 6211 6212
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);
}

6213
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6214 6215
{
	rbd_free_disk(rbd_dev);
6216 6217 6218 6219 6220

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

6221
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6222
	device_del(&rbd_dev->dev);
A
Alex Elder 已提交
6223
	rbd_dev_mapping_clear(rbd_dev);
6224 6225
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
6226 6227
}

6228 6229
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6230
	while (rbd_dev->parent) {
6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242
		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
6243
		rbd_assert(second);
6244
		rbd_dev_image_release(second);
A
Alex Elder 已提交
6245 6246 6247 6248
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6249 6250 6251 6252 6253
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6254 6255 6256
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6257 6258
{
	struct rbd_device *rbd_dev = NULL;
6259 6260
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6261
	char opt_buf[6];
6262
	bool already = false;
M
Mike Christie 已提交
6263
	bool force = false;
6264
	int ret;
6265

M
Mike Christie 已提交
6266 6267 6268 6269 6270
	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");
6271
		return -EINVAL;
M
Mike Christie 已提交
6272 6273 6274 6275 6276 6277 6278 6279 6280
	}
	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;
		}
	}
6281

6282 6283 6284 6285 6286 6287 6288 6289
	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;
		}
6290
	}
6291 6292
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6293
		if (rbd_dev->open_count && !force)
6294 6295
			ret = -EBUSY;
		else
6296 6297
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6298 6299 6300
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6301
	if (ret < 0 || already)
6302
		return ret;
6303

M
Mike Christie 已提交
6304 6305 6306 6307 6308 6309 6310 6311 6312
	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);
	}

6313 6314 6315 6316
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
6317
	rbd_unregister_watch(rbd_dev);
6318

6319 6320 6321 6322 6323 6324
	/*
	 * 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.
	 */
6325
	rbd_dev_device_release(rbd_dev);
6326
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
6327

6328
	return count;
6329 6330
}

6331 6332 6333 6334 6335 6336 6337 6338 6339 6340 6341 6342 6343 6344 6345 6346 6347
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);
}

6348 6349
/*
 * create control files in sysfs
6350
 * /sys/bus/rbd/...
6351 6352 6353
 */
static int rbd_sysfs_init(void)
{
6354
	int ret;
6355

6356
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6357
	if (ret < 0)
6358
		return ret;
6359

6360 6361 6362
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6363 6364 6365 6366 6367 6368

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6369
	bus_unregister(&rbd_bus_type);
6370
	device_unregister(&rbd_root_dev);
6371 6372
}

6373 6374 6375
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6376
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6377 6378 6379 6380
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6381
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6382 6383 6384 6385 6386
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6387
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6388
	if (rbd_segment_name_cache)
6389
		return 0;
6390
out_err:
6391 6392
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6393

6394 6395 6396
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

6397 6398 6399 6400 6401
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6402 6403 6404 6405
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

6406 6407 6408 6409
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6410 6411 6412 6413 6414
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
6415
static int __init rbd_init(void)
6416 6417 6418
{
	int rc;

6419 6420 6421 6422
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6423

6424
	rc = rbd_slab_init();
6425 6426
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6427

6428 6429
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6430
	 * rbd devices * queue depth, so leave @max_active at default.
6431 6432 6433 6434 6435 6436 6437
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6438 6439 6440 6441
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6442
			goto err_out_wq;
6443 6444 6445
		}
	}

6446 6447
	rc = rbd_sysfs_init();
	if (rc)
6448 6449 6450 6451 6452 6453
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6454

I
Ilya Dryomov 已提交
6455 6456
	return 0;

6457 6458 6459
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6460 6461
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6462 6463
err_out_slab:
	rbd_slab_exit();
6464
	return rc;
6465 6466
}

A
Alex Elder 已提交
6467
static void __exit rbd_exit(void)
6468
{
I
Ilya Dryomov 已提交
6469
	ida_destroy(&rbd_dev_id_ida);
6470
	rbd_sysfs_cleanup();
6471 6472
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6473
	destroy_workqueue(rbd_wq);
6474
	rbd_slab_exit();
6475 6476 6477 6478 6479
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6480
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6481 6482 6483 6484 6485
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>");

6486
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6487
MODULE_LICENSE("GPL");