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		(1ULL<<0)
#define RBD_FEATURE_STRIPINGV2		(1ULL<<1)
#define RBD_FEATURE_EXCLUSIVE_LOCK	(1ULL<<2)
#define RBD_FEATURE_DATA_POOL		(1ULL<<7)
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#define RBD_FEATURE_OPERATIONS		(1ULL<<8)
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#define RBD_FEATURES_ALL	(RBD_FEATURE_LAYERING |		\
				 RBD_FEATURE_STRIPINGV2 |	\
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				 RBD_FEATURE_EXCLUSIVE_LOCK |	\
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				 RBD_FEATURE_DATA_POOL |	\
				 RBD_FEATURE_OPERATIONS)
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/* Features supported by this (client software) implementation. */

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

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

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

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

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struct rbd_img_request;
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 {
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	u64			object_no;
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	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;

	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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};

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

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

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

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	spinlock_t		lock;		/* queue, flags, open_count */
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	struct rbd_image_header	header;
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	unsigned long		flags;		/* possibly lock protected */
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	struct rbd_spec		*spec;
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	struct rbd_options	*opts;
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	char			*config_info;	/* add{,_single_major} string */
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	struct ceph_object_id	header_oid;
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	struct ceph_object_locator header_oloc;
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	struct ceph_file_layout	layout;		/* used for all rbd requests */
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	struct mutex		watch_mutex;
	enum rbd_watch_state	watch_state;
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	struct ceph_osd_linger_request *watch_handle;
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	u64			watch_cookie;
	struct delayed_work	watch_dwork;
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	struct rw_semaphore	lock_rwsem;
	enum rbd_lock_state	lock_state;
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	char			lock_cookie[32];
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	struct rbd_client_id	owner_cid;
	struct work_struct	acquired_lock_work;
	struct work_struct	released_lock_work;
	struct delayed_work	lock_dwork;
	struct work_struct	unlock_work;
	wait_queue_head_t	lock_waitq;

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

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

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/*
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 * Flag bits for rbd_dev->flags:
 * - REMOVING (which is coupled with rbd_dev->open_count) is protected
 *   by rbd_dev->lock
 * - BLACKLISTED is protected by rbd_dev->lock_rwsem
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 */
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enum rbd_dev_flags {
	RBD_DEV_FLAG_EXISTS,	/* mapped snapshot has not been deleted */
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	RBD_DEV_FLAG_REMOVING,	/* this mapping is being removed */
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	RBD_DEV_FLAG_BLACKLISTED, /* our ceph_client is blacklisted */
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};

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static DEFINE_MUTEX(client_mutex);	/* Serialize client creation */
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static LIST_HEAD(rbd_dev_list);    /* devices */
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static DEFINE_SPINLOCK(rbd_dev_list_lock);

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static LIST_HEAD(rbd_client_list);		/* clients */
static DEFINE_SPINLOCK(rbd_client_list_lock);
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/* Slab caches for frequently-allocated structures */

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static struct kmem_cache	*rbd_img_request_cache;
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static struct kmem_cache	*rbd_obj_request_cache;
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static struct bio_set		*rbd_bio_clone;

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static int rbd_major;
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static DEFINE_IDA(rbd_dev_id_ida);

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static struct workqueue_struct *rbd_wq;

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/*
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 * single-major requires >= 0.75 version of userspace rbd utility.
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 */
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static bool single_major = true;
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module_param(single_major, bool, S_IRUGO);
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MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: true)");
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static 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_owner(struct rbd_device *rbd_dev)
{
	return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
	       rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
}

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

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

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

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

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	return attr->mode;
}

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

static void rbd_root_dev_release(struct device *dev)
{
}

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

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

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

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

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#ifdef RBD_DEBUG
#define rbd_assert(expr)						\
		if (unlikely(!(expr))) {				\
			printk(KERN_ERR "\nAssertion failure in %s() "	\
						"at line %d:\n\n"	\
					"\trbd_assert(%s);\n\n",	\
					__func__, __LINE__, #expr);	\
			BUG();						\
		}
#else /* !RBD_DEBUG */
#  define rbd_assert(expr)	((void) 0)
#endif /* !RBD_DEBUG */
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static void rbd_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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A
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594
static int rbd_dev_refresh(struct rbd_device *rbd_dev);
595
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
596
static int rbd_dev_header_info(struct rbd_device *rbd_dev);
597
static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
598 599
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id);
600 601 602 603
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);
604

605 606
static int rbd_open(struct block_device *bdev, fmode_t mode)
{
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607
	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
608
	bool removing = false;
609

610
	spin_lock_irq(&rbd_dev->lock);
611 612 613 614
	if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
		removing = true;
	else
		rbd_dev->open_count++;
615
	spin_unlock_irq(&rbd_dev->lock);
616 617 618
	if (removing)
		return -ENOENT;

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619
	(void) get_device(&rbd_dev->dev);
620

621 622 623
	return 0;
}

624
static void rbd_release(struct gendisk *disk, fmode_t mode)
625 626
{
	struct rbd_device *rbd_dev = disk->private_data;
627 628
	unsigned long open_count_before;

629
	spin_lock_irq(&rbd_dev->lock);
630
	open_count_before = rbd_dev->open_count--;
631
	spin_unlock_irq(&rbd_dev->lock);
632
	rbd_assert(open_count_before > 0);
633

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634
	put_device(&rbd_dev->dev);
635 636
}

G
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637 638
static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
639
	int ro;
G
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640

641
	if (get_user(ro, (int __user *)arg))
G
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642 643
		return -EFAULT;

644
	/* Snapshots can't be marked read-write */
G
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645 646 647
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
		return -EROFS;

648 649
	/* Let blkdev_roset() handle it */
	return -ENOTTY;
G
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650 651 652 653 654 655
}

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;
656
	int ret;
G
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657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676

	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 */

677 678 679
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
680
	.release		= rbd_release,
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Guangliang Zhao 已提交
681 682 683 684
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
685 686 687
};

/*
688
 * Initialize an rbd client instance.  Success or not, this function
689
 * consumes ceph_opts.  Caller holds client_mutex.
690
 */
691
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
692 693 694 695
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

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696
	dout("%s:\n", __func__);
697 698 699 700 701 702 703
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

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

704
	rbdc->client = ceph_create_client(ceph_opts, rbdc);
705
	if (IS_ERR(rbdc->client))
706
		goto out_rbdc;
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707
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
708 709 710

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
711
		goto out_client;
712

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713
	spin_lock(&rbd_client_list_lock);
714
	list_add_tail(&rbdc->node, &rbd_client_list);
A
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715
	spin_unlock(&rbd_client_list_lock);
716

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717
	dout("%s: rbdc %p\n", __func__, rbdc);
718

719
	return rbdc;
720
out_client:
721
	ceph_destroy_client(rbdc->client);
722
out_rbdc:
723 724
	kfree(rbdc);
out_opt:
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725 726
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
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727 728
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
729
	return ERR_PTR(ret);
730 731
}

732 733 734 735 736 737 738
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

739
/*
740 741
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
742
 */
743
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
744 745
{
	struct rbd_client *client_node;
746
	bool found = false;
747

A
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748
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
749 750
		return NULL;

751 752 753
	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)) {
754 755
			__rbd_get_client(client_node);

756 757 758 759 760 761 762
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
763 764
}

765
/*
766
 * (Per device) rbd map options
767 768
 */
enum {
I
Ilya Dryomov 已提交
769
	Opt_queue_depth,
770 771 772 773
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
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774 775
	Opt_read_only,
	Opt_read_write,
I
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776
	Opt_lock_on_read,
I
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777
	Opt_exclusive,
778
	Opt_err
779 780
};

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781
static match_table_t rbd_opts_tokens = {
I
Ilya Dryomov 已提交
782
	{Opt_queue_depth, "queue_depth=%d"},
783 784
	/* int args above */
	/* string args above */
A
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785
	{Opt_read_only, "read_only"},
A
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786 787 788
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
I
Ilya Dryomov 已提交
789
	{Opt_lock_on_read, "lock_on_read"},
I
Ilya Dryomov 已提交
790
	{Opt_exclusive, "exclusive"},
791
	{Opt_err, NULL}
792 793
};

A
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794
struct rbd_options {
I
Ilya Dryomov 已提交
795
	int	queue_depth;
A
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796
	bool	read_only;
I
Ilya Dryomov 已提交
797
	bool	lock_on_read;
I
Ilya Dryomov 已提交
798
	bool	exclusive;
A
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799 800
};

I
Ilya Dryomov 已提交
801
#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
A
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802
#define RBD_READ_ONLY_DEFAULT	false
I
Ilya Dryomov 已提交
803
#define RBD_LOCK_ON_READ_DEFAULT false
I
Ilya Dryomov 已提交
804
#define RBD_EXCLUSIVE_DEFAULT	false
A
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805

806 807
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
808
	struct rbd_options *rbd_opts = private;
809 810 811
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
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812
	token = match_token(c, rbd_opts_tokens, argstr);
813 814 815
	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
816
			pr_err("bad mount option arg (not int) at '%s'\n", c);
817 818 819 820
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
821
		dout("got string token %d val %s\n", token, argstr[0].from);
822 823 824 825 826
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
I
Ilya Dryomov 已提交
827 828 829 830 831 832 833
	case Opt_queue_depth:
		if (intval < 1) {
			pr_err("queue_depth out of range\n");
			return -EINVAL;
		}
		rbd_opts->queue_depth = intval;
		break;
A
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834 835 836 837 838 839
	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
840 841 842
	case Opt_lock_on_read:
		rbd_opts->lock_on_read = true;
		break;
I
Ilya Dryomov 已提交
843 844 845
	case Opt_exclusive:
		rbd_opts->exclusive = true;
		break;
846
	default:
847 848
		/* libceph prints "bad option" msg */
		return -EINVAL;
849
	}
850

851 852 853
	return 0;
}

G
Guangliang Zhao 已提交
854 855 856 857 858 859 860
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";
861 862
	case OBJ_OP_DISCARD:
		return "discard";
G
Guangliang Zhao 已提交
863 864 865 866 867
	default:
		return "???";
	}
}

868 869
/*
 * Get a ceph client with specific addr and configuration, if one does
870 871
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
872
 */
873
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
874
{
875
	struct rbd_client *rbdc;
876

877
	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
878
	rbdc = rbd_client_find(ceph_opts);
879
	if (rbdc)	/* using an existing client */
A
Alex Elder 已提交
880
		ceph_destroy_options(ceph_opts);
881
	else
882
		rbdc = rbd_client_create(ceph_opts);
883
	mutex_unlock(&client_mutex);
884

885
	return rbdc;
886 887 888 889
}

/*
 * Destroy ceph client
A
Alex Elder 已提交
890
 *
A
Alex Elder 已提交
891
 * Caller must hold rbd_client_list_lock.
892 893 894 895 896
 */
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
897
	dout("%s: rbdc %p\n", __func__, rbdc);
898
	spin_lock(&rbd_client_list_lock);
899
	list_del(&rbdc->node);
900
	spin_unlock(&rbd_client_list_lock);
901 902 903 904 905 906 907 908 909

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

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
910
static void rbd_put_client(struct rbd_client *rbdc)
911
{
912 913
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
914 915
}

916 917 918 919 920
static bool rbd_image_format_valid(u32 image_format)
{
	return image_format == 1 || image_format == 2;
}

921 922
static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
{
923 924 925 926 927 928 929
	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
930 931 932 933 934 935 936 937 938 939
	/* 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;

940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957
	/*
	 * 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;
958 959
}

I
Ilya Dryomov 已提交
960 961 962 963 964 965 966 967
/*
 * 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
968 969 970 971 972 973 974 975 976 977 978
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);
979 980
	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
981 982 983
	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
}

984
/*
985 986
 * Fill an rbd image header with information from the given format 1
 * on-disk header.
987
 */
A
Alex Elder 已提交
988
static int rbd_header_from_disk(struct rbd_device *rbd_dev,
989
				 struct rbd_image_header_ondisk *ondisk)
990
{
A
Alex Elder 已提交
991
	struct rbd_image_header *header = &rbd_dev->header;
992 993 994 995 996
	bool first_time = header->object_prefix == NULL;
	struct ceph_snap_context *snapc;
	char *object_prefix = NULL;
	char *snap_names = NULL;
	u64 *snap_sizes = NULL;
997
	u32 snap_count;
998
	int ret = -ENOMEM;
999
	u32 i;
1000

1001
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
1002

1003
	if (first_time) {
1004 1005 1006
		object_prefix = kstrndup(ondisk->object_prefix,
					 sizeof(ondisk->object_prefix),
					 GFP_KERNEL);
1007 1008 1009
		if (!object_prefix)
			return -ENOMEM;
	}
A
Alex Elder 已提交
1010

1011
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
1012

1013 1014 1015 1016 1017
	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);
1018
	if (snap_count) {
1019
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
1020 1021
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

1022
		/* We'll keep a copy of the snapshot names... */
1023

1024 1025 1026 1027
		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
1028 1029
			goto out_err;

1030
		/* ...as well as the array of their sizes. */
1031 1032 1033
		snap_sizes = kmalloc_array(snap_count,
					   sizeof(*header->snap_sizes),
					   GFP_KERNEL);
1034
		if (!snap_sizes)
A
Alex Elder 已提交
1035
			goto out_err;
1036

A
Alex Elder 已提交
1037
		/*
1038 1039 1040
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
1041
		 * Note that rbd_dev_v1_header_info() guarantees the
1042
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
1043 1044 1045
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
1046 1047 1048 1049 1050 1051
		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);
		}
1052
	}
A
Alex Elder 已提交
1053

1054
	/* We won't fail any more, fill in the header */
1055

1056 1057 1058
	if (first_time) {
		header->object_prefix = object_prefix;
		header->obj_order = ondisk->options.order;
I
Ilya Dryomov 已提交
1059
		rbd_init_layout(rbd_dev);
1060
	} else {
A
Alex Elder 已提交
1061 1062 1063
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
1064
	}
1065

1066
	/* The remaining fields always get updated (when we refresh) */
1067

A
Alex Elder 已提交
1068
	header->image_size = le64_to_cpu(ondisk->image_size);
1069 1070 1071
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1072

1073
	return 0;
1074 1075
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1076
out_err:
1077 1078 1079 1080
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1081

1082
	return ret;
1083 1084
}

1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
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);
}

1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
/*
 * 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.
 */
1124 1125 1126
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1127
	u64 *found;
1128

1129 1130
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1131

1132
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1133 1134
}

1135 1136
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1137
{
1138
	u32 which;
1139
	const char *snap_name;
1140

1141 1142
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1143
		return ERR_PTR(-ENOENT);
1144

1145 1146
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1147 1148 1149 1150
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1151 1152 1153
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1154 1155 1156
	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);
1157

1158
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1159 1160
}

1161 1162
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1163
{
1164 1165 1166 1167 1168
	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;
1169

1170 1171 1172
		which = rbd_dev_snap_index(rbd_dev, snap_id);
		if (which == BAD_SNAP_INDEX)
			return -ENOENT;
1173

1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
		*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;
1186 1187
}

1188 1189
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1190
{
1191 1192 1193 1194 1195
	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 */
1196
	} else {
1197 1198
		u64 features = 0;
		int ret;
1199

1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
		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)
{
1211
	u64 snap_id = rbd_dev->spec->snap_id;
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
	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;

1226
	return 0;
1227 1228
}

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1229 1230 1231 1232
static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
{
	rbd_dev->mapping.size = 0;
	rbd_dev->mapping.features = 0;
1233 1234
}

A
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1235 1236
static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
I
Ilya Dryomov 已提交
1237
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
1238

A
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1239 1240 1241 1242 1243 1244
	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
1245
	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
A
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1246 1247 1248

	offset &= segment_size - 1;

A
Alex Elder 已提交
1249
	rbd_assert(length <= U64_MAX - offset);
A
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1250 1251 1252 1253
	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275
}

/*
 * 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)
{
1276 1277
	struct bio_vec bv;
	struct bvec_iter iter;
1278 1279 1280 1281 1282
	unsigned long flags;
	void *buf;
	int pos = 0;

	while (chain) {
1283 1284
		bio_for_each_segment(bv, chain, iter) {
			if (pos + bv.bv_len > start_ofs) {
1285
				int remainder = max(start_ofs - pos, 0);
1286
				buf = bvec_kmap_irq(&bv, &flags);
1287
				memset(buf + remainder, 0,
1288 1289
				       bv.bv_len - remainder);
				flush_dcache_page(bv.bv_page);
1290
				bvec_kunmap_irq(buf, &flags);
1291
			}
1292
			pos += bv.bv_len;
1293 1294 1295 1296 1297 1298
		}

		chain = chain->bi_next;
	}
}

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1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316
/*
 * 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;

1317 1318
		page_offset = offset & ~PAGE_MASK;
		length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
A
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1319 1320 1321
		local_irq_save(flags);
		kaddr = kmap_atomic(*page);
		memset(kaddr + page_offset, 0, length);
1322
		flush_dcache_page(*page);
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1323 1324 1325 1326 1327 1328 1329 1330
		kunmap_atomic(kaddr);
		local_irq_restore(flags);

		offset += length;
		page++;
	}
}

1331
/*
A
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1332 1333
 * Clone a portion of a bio, starting at the given byte offset
 * and continuing for the number of bytes indicated.
1334
 */
A
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1335 1336 1337 1338
static struct bio *bio_clone_range(struct bio *bio_src,
					unsigned int offset,
					unsigned int len,
					gfp_t gfpmask)
1339
{
A
Alex Elder 已提交
1340 1341
	struct bio *bio;

1342
	bio = bio_clone_fast(bio_src, gfpmask, rbd_bio_clone);
A
Alex Elder 已提交
1343 1344
	if (!bio)
		return NULL;	/* ENOMEM */
1345

K
Kent Overstreet 已提交
1346
	bio_advance(bio, offset);
1347
	bio->bi_iter.bi_size = len;
A
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1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377

	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 */

1378
	if (!bi || off >= bi->bi_iter.bi_size || !len)
A
Alex Elder 已提交
1379
		return NULL;		/* Nothing to clone */
1380

A
Alex Elder 已提交
1381 1382 1383 1384 1385
	end = &chain;
	while (len) {
		unsigned int bi_size;
		struct bio *bio;

1386 1387
		if (!bi) {
			rbd_warn(NULL, "bio_chain exhausted with %u left", len);
A
Alex Elder 已提交
1388
			goto out_err;	/* EINVAL; ran out of bio's */
1389
		}
1390
		bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
A
Alex Elder 已提交
1391 1392 1393 1394 1395 1396
		bio = bio_clone_range(bi, off, bi_size, gfpmask);
		if (!bio)
			goto out_err;	/* ENOMEM */

		*end = bio;
		end = &bio->bi_next;
1397

A
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1398
		off += bi_size;
1399
		if (off == bi->bi_iter.bi_size) {
A
Alex Elder 已提交
1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410
			bi = bi->bi_next;
			off = 0;
		}
		len -= bi_size;
	}
	*bio_src = bi;
	*offset = off;

	return chain;
out_err:
	bio_chain_put(chain);
1411 1412 1413 1414

	return NULL;
}

1415 1416 1417 1418 1419
/*
 * 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
1420
static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1421
{
A
Alex Elder 已提交
1422
	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1423 1424
		struct rbd_device *rbd_dev;

A
Alex Elder 已提交
1425
		rbd_dev = obj_request->img_request->rbd_dev;
1426
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1427 1428 1429 1430
			obj_request);
	}
}

A
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1431
static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1432 1433
{
	smp_mb();
A
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1434
	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1435 1436
}

A
Alex Elder 已提交
1437
static void obj_request_done_set(struct rbd_obj_request *obj_request)
1438
{
A
Alex Elder 已提交
1439 1440
	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1441

A
Alex Elder 已提交
1442 1443
		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1444
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1445 1446 1447 1448
			obj_request);
	}
}

A
Alex Elder 已提交
1449
static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1450 1451
{
	smp_mb();
A
Alex Elder 已提交
1452
	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1453 1454
}

1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485
/*
 * 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;
}

1486 1487 1488 1489 1490 1491 1492 1493
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
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1494 1495
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1496
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
1497
		kref_read(&obj_request->kref));
A
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1498 1499 1500 1501 1502 1503 1504
	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
1505
	dout("%s: obj %p (was %d)\n", __func__, obj_request,
1506
		kref_read(&obj_request->kref));
A
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1507 1508 1509
	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1510 1511 1512
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
1513
	     kref_read(&img_request->kref));
1514 1515 1516
	kref_get(&img_request->kref);
}

1517 1518
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
A
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1519 1520 1521 1522
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
1523
	dout("%s: img %p (was %d)\n", __func__, img_request,
1524
		kref_read(&img_request->kref));
1525 1526 1527 1528
	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
1529 1530 1531 1532 1533
}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1534 1535
	rbd_assert(obj_request->img_request == NULL);

1536
	/* Image request now owns object's original reference */
A
Alex Elder 已提交
1537
	obj_request->img_request = img_request;
1538
	obj_request->which = img_request->obj_request_count;
1539 1540
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
A
Alex Elder 已提交
1541
	rbd_assert(obj_request->which != BAD_WHICH);
1542 1543
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
A
Alex Elder 已提交
1544 1545
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1546 1547 1548 1549 1550 1551
}

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);
1552

A
Alex Elder 已提交
1553 1554
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
Alex Elder 已提交
1555
	list_del(&obj_request->links);
1556 1557 1558 1559
	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;
1560
	rbd_assert(obj_request_img_data_test(obj_request));
A
Alex Elder 已提交
1561 1562
	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1563
	obj_request->callback = NULL;
A
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1564 1565 1566 1567 1568 1569
	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1570
	case OBJ_REQUEST_NODATA:
A
Alex Elder 已提交
1571
	case OBJ_REQUEST_BIO:
1572
	case OBJ_REQUEST_PAGES:
A
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1573 1574 1575 1576 1577 1578
		return true;
	default:
		return false;
	}
}

1579 1580
static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);

1581
static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1582
{
1583 1584
	struct ceph_osd_request *osd_req = obj_request->osd_req;

1585 1586
	dout("%s %p object_no %016llx %llu~%llu osd_req %p\n", __func__,
	     obj_request, obj_request->object_no, obj_request->offset,
1587
	     obj_request->length, osd_req);
1588 1589 1590 1591
	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);
	}
1592
	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
A
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1593 1594 1595 1596
}

static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1597

A
Alex Elder 已提交
1598
	dout("%s: img %p\n", __func__, img_request);
1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614

	/*
	 * 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
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1615 1616 1617 1618 1619 1620
	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

A
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1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637
/*
 * 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;
}

1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652
/*
 * 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;
}

1653 1654 1655 1656 1657 1658
static void img_request_child_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1659 1660 1661 1662 1663 1664
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1665 1666 1667 1668 1669 1670
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

1671 1672 1673 1674 1675 1676
static void img_request_layered_set(struct rbd_img_request *img_request)
{
	set_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1677 1678 1679 1680 1681 1682
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1683 1684 1685 1686 1687 1688
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699
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;
}

1700 1701 1702
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1703 1704 1705
	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1706 1707
	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
1708
		xferred, length);
1709
	/*
1710 1711 1712 1713 1714 1715
	 * 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.
1716
	 */
A
Alex Elder 已提交
1717
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1718
	if (obj_request->result == -ENOENT) {
A
Alex Elder 已提交
1719 1720 1721 1722
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1723
		obj_request->result = 0;
A
Alex Elder 已提交
1724 1725 1726 1727 1728
	} 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);
1729
	}
1730
	obj_request->xferred = length;
1731 1732 1733
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1734 1735
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1736 1737
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
1738
	obj_request->callback(obj_request);
A
Alex Elder 已提交
1739 1740
}

1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756
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);
}

1757
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1758
{
A
Alex Elder 已提交
1759
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1760
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1761 1762 1763 1764 1765
	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
1766
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1767
	}
A
Alex Elder 已提交
1768 1769 1770 1771

	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
1772 1773
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1774 1775
		rbd_img_parent_read(obj_request);
	else if (img_request)
1776 1777 1778
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1779 1780
}

1781
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1782
{
1783 1784 1785
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1786 1787
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1788 1789
	 */
	obj_request->xferred = obj_request->length;
1790
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1791 1792
}

1793 1794 1795 1796 1797 1798 1799 1800 1801
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;
1802 1803 1804
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1805 1806 1807
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1808 1809 1810 1811
/*
 * 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.
 */
1812
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1813
{
A
Alex Elder 已提交
1814
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1815 1816 1817
	obj_request_done_set(obj_request);
}

I
Ilya Dryomov 已提交
1818 1819 1820 1821 1822 1823 1824 1825 1826 1827
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);
}

1828
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
A
Alex Elder 已提交
1829 1830 1831 1832
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

1833
	dout("%s: osd_req %p\n", __func__, osd_req);
A
Alex Elder 已提交
1834
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1835 1836 1837 1838 1839 1840
	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
1841

1842 1843
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1844

1845 1846
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1847 1848
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1849
	 */
1850
	obj_request->xferred = osd_req->r_ops[0].outdata_len;
A
Alex Elder 已提交
1851
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1852

1853
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1854 1855
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1856
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1857
		break;
1858
	case CEPH_OSD_OP_SETALLOCHINT:
1859 1860
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
			   osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1861
		/* fall through */
A
Alex Elder 已提交
1862
	case CEPH_OSD_OP_WRITE:
1863
	case CEPH_OSD_OP_WRITEFULL:
1864
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1865
		break;
A
Alex Elder 已提交
1866
	case CEPH_OSD_OP_STAT:
1867
		rbd_osd_stat_callback(obj_request);
A
Alex Elder 已提交
1868
		break;
1869 1870 1871 1872 1873
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1874
	case CEPH_OSD_OP_CALL:
I
Ilya Dryomov 已提交
1875 1876
		rbd_osd_call_callback(obj_request);
		break;
A
Alex Elder 已提交
1877
	default:
1878 1879
		rbd_warn(NULL, "unexpected OSD op: object_no %016llx opcode %d",
			 obj_request->object_no, opcode);
A
Alex Elder 已提交
1880 1881 1882
		break;
	}

1883
	if (obj_request_done_test(obj_request))
A
Alex Elder 已提交
1884 1885 1886
		rbd_obj_request_complete(obj_request);
}

1887
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1888
{
1889
	struct ceph_osd_request *osd_req = obj_request->osd_req;
A
Alex Elder 已提交
1890

1891 1892
	rbd_assert(obj_request_img_data_test(obj_request));
	osd_req->r_snapid = obj_request->img_request->snap_id;
1893 1894 1895 1896 1897 1898
}

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

1899
	ktime_get_real_ts(&osd_req->r_mtime);
1900
	osd_req->r_data_offset = obj_request->offset;
A
Alex Elder 已提交
1901 1902
}

1903 1904 1905 1906 1907 1908 1909 1910
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;
1911 1912
	const char *name_format = rbd_dev->image_format == 1 ?
				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
1913 1914 1915 1916 1917 1918 1919 1920 1921 1922

	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;
1923 1924
	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
			rbd_dev->header.object_prefix, obj_request->object_no))
1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936
		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;
}

1937 1938 1939 1940 1941 1942
/*
 * 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
1943 1944
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1945
					enum obj_operation_type op_type,
1946
					unsigned int num_ops,
A
Alex Elder 已提交
1947
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1948 1949 1950
{
	struct ceph_snap_context *snapc = NULL;

1951 1952
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1953
		struct rbd_img_request *img_request = obj_request->img_request;
1954 1955 1956 1957 1958
		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
1959
		snapc = img_request->snapc;
A
Alex Elder 已提交
1960 1961
	}

G
Guangliang Zhao 已提交
1962
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1963

1964 1965
	return __rbd_osd_req_create(rbd_dev, snapc, num_ops,
	    (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD) ?
1966
	    CEPH_OSD_FLAG_WRITE : CEPH_OSD_FLAG_READ, obj_request);
A
Alex Elder 已提交
1967 1968
}

1969
/*
1970 1971 1972 1973
 * 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.
1974 1975 1976 1977 1978
 */
static struct ceph_osd_request *
rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
1979
	int num_osd_ops = 3;
1980 1981 1982 1983

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
1984 1985
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
1986

1987 1988 1989
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

1990 1991
	return __rbd_osd_req_create(img_request->rbd_dev,
				    img_request->snapc, num_osd_ops,
1992
				    CEPH_OSD_FLAG_WRITE, obj_request);
1993 1994
}

A
Alex Elder 已提交
1995 1996 1997 1998 1999
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

2000 2001
static struct rbd_obj_request *
rbd_obj_request_create(enum obj_request_type type)
A
Alex Elder 已提交
2002 2003 2004 2005 2006
{
	struct rbd_obj_request *obj_request;

	rbd_assert(obj_request_type_valid(type));

2007
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2008
	if (!obj_request)
2009 2010
		return NULL;

A
Alex Elder 已提交
2011 2012 2013 2014 2015
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
	kref_init(&obj_request->kref);

2016
	dout("%s %p\n", __func__, obj_request);
A
Alex Elder 已提交
2017 2018 2019 2020 2021 2022 2023 2024 2025
	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
2026 2027
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2028 2029 2030 2031 2032 2033 2034 2035
	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) {
2036 2037
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2038 2039 2040 2041
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2042
	case OBJ_REQUEST_PAGES:
2043 2044 2045
		/* img_data requests don't own their page array */
		if (obj_request->pages &&
		    !obj_request_img_data_test(obj_request))
2046 2047 2048
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2049 2050
	}

2051
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2052 2053
}

A
Alex Elder 已提交
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064
/* 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;
}

2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086
/*
 * 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
2087
		rbd_warn(rbd_dev, "parent reference underflow");
2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099
}

/*
 * 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)
{
2100
	int counter = 0;
2101 2102 2103 2104

	if (!rbd_dev->parent_spec)
		return false;

2105 2106 2107 2108
	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);
2109 2110

	if (counter < 0)
2111
		rbd_warn(rbd_dev, "parent reference overflow");
2112

2113
	return counter > 0;
2114 2115
}

A
Alex Elder 已提交
2116 2117 2118 2119 2120
/*
 * 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
2121 2122
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2123
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2124
					enum obj_operation_type op_type,
2125
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2126 2127 2128
{
	struct rbd_img_request *img_request;

2129
	img_request = kmem_cache_zalloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2130 2131 2132 2133 2134 2135
	if (!img_request)
		return NULL;

	img_request->rbd_dev = rbd_dev;
	img_request->offset = offset;
	img_request->length = length;
2136 2137 2138 2139
	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
2140
		img_request_write_set(img_request);
2141
		img_request->snapc = snapc;
A
Alex Elder 已提交
2142
	} else {
A
Alex Elder 已提交
2143
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2144
	}
2145
	if (rbd_dev_parent_get(rbd_dev))
2146
		img_request_layered_set(img_request);
2147

A
Alex Elder 已提交
2148 2149 2150 2151
	spin_lock_init(&img_request->completion_lock);
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2152
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2153
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2154

A
Alex Elder 已提交
2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165
	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
2166 2167
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2168 2169
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2170
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2171

2172 2173 2174 2175 2176
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2177 2178
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2179
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2180

2181
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2182 2183
}

2184 2185 2186 2187 2188 2189 2190 2191 2192 2193
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;

2194
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2195
						length, OBJ_OP_READ, NULL);
2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220
	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);
}

2221 2222
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2223
	struct rbd_img_request *img_request;
2224 2225
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2226
	bool more;
2227

2228 2229 2230
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2231 2232 2233 2234 2235
	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
2236 2237
		enum obj_operation_type op_type;

2238 2239 2240 2241 2242 2243
		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;
2244

2245
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2246 2247
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2248
		rbd_warn(rbd_dev, "  result %d xferred %x",
2249 2250 2251
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2252 2253 2254 2255 2256
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2257 2258
	}

A
Alex Elder 已提交
2259 2260 2261 2262
	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 {
2263 2264
		blk_status_t status = errno_to_blk_status(result);

A
Alex Elder 已提交
2265
		rbd_assert(img_request->rq != NULL);
C
Christoph Hellwig 已提交
2266

2267
		more = blk_update_request(img_request->rq, status, xferred);
C
Christoph Hellwig 已提交
2268
		if (!more)
2269
			__blk_mq_end_request(img_request->rq, status);
A
Alex Elder 已提交
2270 2271 2272
	}

	return more;
2273 2274
}

2275 2276 2277 2278 2279 2280
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;

2281
	rbd_assert(obj_request_img_data_test(obj_request));
2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299
	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;
2300
		more = rbd_img_obj_end_request(obj_request);
2301 2302 2303 2304 2305 2306 2307
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2308
	rbd_img_request_put(img_request);
2309 2310 2311 2312 2313

	if (!more)
		rbd_img_request_complete(img_request);
}

2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332
/*
 * 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) {
2333 2334 2335
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
			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) {
2350 2351 2352 2353
		if (!offset && length == object_size)
			opcode = CEPH_OSD_OP_WRITEFULL;
		else
			opcode = CEPH_OSD_OP_WRITE;
2354 2355 2356 2357 2358 2359 2360
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2361
	if (opcode == CEPH_OSD_OP_DELETE)
2362
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2363 2364 2365 2366
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381
	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);
}

2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392
/*
 * 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
2393 2394 2395 2396
{
	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
2397
	struct bio *bio_list = NULL;
2398
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2399
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2400
	enum obj_operation_type op_type;
2401
	u64 img_offset;
A
Alex Elder 已提交
2402 2403
	u64 resid;

2404 2405
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2406

2407
	img_offset = img_request->offset;
A
Alex Elder 已提交
2408
	resid = img_request->length;
A
Alex Elder 已提交
2409
	rbd_assert(resid > 0);
2410
	op_type = rbd_img_request_op_type(img_request);
2411 2412 2413

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2414 2415
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2416
	} else if (type == OBJ_REQUEST_PAGES) {
2417 2418 2419
		pages = data_desc;
	}

A
Alex Elder 已提交
2420
	while (resid) {
2421
		struct ceph_osd_request *osd_req;
2422
		u64 object_no = img_offset >> rbd_dev->header.obj_order;
2423 2424
		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
2425

2426
		obj_request = rbd_obj_request_create(type);
A
Alex Elder 已提交
2427 2428
		if (!obj_request)
			goto out_unwind;
2429

2430
		obj_request->object_no = object_no;
2431 2432 2433
		obj_request->offset = offset;
		obj_request->length = length;

2434 2435 2436 2437 2438
		/*
		 * 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
2439

2440 2441 2442 2443 2444 2445 2446 2447 2448
		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,
2449
								GFP_NOIO);
2450
			if (!obj_request->bio_list)
2451
				goto out_unwind;
2452
		} else if (type == OBJ_REQUEST_PAGES) {
2453 2454 2455 2456 2457 2458 2459 2460 2461
			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
2462

G
Guangliang Zhao 已提交
2463 2464 2465
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2466
		if (!osd_req)
2467
			goto out_unwind;
2468

2469
		obj_request->osd_req = osd_req;
2470
		obj_request->callback = rbd_img_obj_callback;
2471
		obj_request->img_offset = img_offset;
2472

2473
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2474

2475
		img_offset += length;
A
Alex Elder 已提交
2476 2477 2478 2479 2480 2481 2482
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2483
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2484 2485 2486 2487

	return -ENOMEM;
}

2488
static void
I
Ilya Dryomov 已提交
2489
rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2490 2491 2492
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2493
	struct page **pages;
2494 2495
	u32 page_count;

I
Ilya Dryomov 已提交
2496 2497
	dout("%s: obj %p\n", __func__, obj_request);

2498 2499
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2500 2501 2502 2503 2504 2505 2506
	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);

2507 2508
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2509
	obj_request->copyup_pages = NULL;
2510 2511 2512 2513
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2514 2515 2516 2517 2518 2519 2520 2521 2522 2523

	/*
	 * 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
2524
	obj_request_done_set(obj_request);
2525 2526
}

2527 2528 2529 2530
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2531 2532
	struct ceph_osd_request *osd_req;
	struct rbd_device *rbd_dev;
2533
	struct page **pages;
2534
	enum obj_operation_type op_type;
2535
	u32 page_count;
2536
	int img_result;
2537
	u64 parent_length;
2538 2539 2540 2541 2542 2543 2544 2545

	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;
2546 2547 2548
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2549 2550 2551

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2552
	rbd_assert(obj_request_type_valid(orig_request->type));
2553
	img_result = img_request->result;
2554
	parent_length = img_request->length;
2555
	rbd_assert(img_result || parent_length == img_request->xferred);
2556
	rbd_img_request_put(img_request);
2557

2558 2559
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2560 2561
	rbd_assert(rbd_dev);

2562 2563 2564 2565 2566 2567 2568
	/*
	 * 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);
2569 2570
		rbd_obj_request_submit(orig_request);
		return;
2571
	}
2572

2573
	if (img_result)
2574 2575
		goto out_err;

2576 2577
	/*
	 * The original osd request is of no use to use any more.
2578
	 * We need a new one that can hold the three ops in a copyup
2579 2580 2581
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2582
	img_result = -ENOMEM;
2583 2584 2585
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2586
	rbd_osd_req_destroy(orig_request->osd_req);
2587 2588
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2589
	orig_request->copyup_page_count = page_count;
2590

2591
	/* Initialize the copyup op */
2592

2593
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2594
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2595
						false, false);
2596

2597
	/* Add the other op(s) */
2598

2599 2600
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2601 2602 2603

	/* All set, send it off. */

2604 2605
	rbd_obj_request_submit(orig_request);
	return;
2606 2607

out_err:
2608
	ceph_release_page_vector(pages, page_count);
2609
	rbd_obj_request_error(orig_request, img_result);
2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622
}

/*
 * 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.
 *
2623 2624
 * If an error occurs, it is recorded as the result of the original
 * object request in rbd_img_obj_exists_callback().
2625 2626 2627
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
2628
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642
	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
2643
	length = rbd_obj_bytes(&rbd_dev->header);
2644

A
Alex Elder 已提交
2645 2646 2647 2648 2649 2650 2651 2652 2653 2654
	/*
	 * 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;
	}

2655 2656 2657 2658 2659
	/*
	 * Allocate a page array big enough to receive the data read
	 * from the parent.
	 */
	page_count = (u32)calc_pages_for(0, length);
2660
	pages = ceph_alloc_page_vector(page_count, GFP_NOIO);
2661 2662 2663 2664 2665 2666 2667
	if (IS_ERR(pages)) {
		result = PTR_ERR(pages);
		pages = NULL;
		goto out_err;
	}

	result = -ENOMEM;
2668 2669
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2670 2671 2672 2673 2674 2675
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
2676

2677
	parent_request->copyup_pages = pages;
2678
	parent_request->copyup_page_count = page_count;
2679
	parent_request->callback = rbd_img_obj_parent_read_full_callback;
2680

2681 2682 2683 2684 2685
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2686
	parent_request->copyup_page_count = 0;
2687 2688 2689 2690 2691 2692 2693 2694
out_err:
	if (pages)
		ceph_release_page_vector(pages, page_count);
	if (parent_request)
		rbd_img_request_put(parent_request);
	return result;
}

2695 2696 2697
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2698
	struct rbd_device *rbd_dev;
2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709
	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;
2710
	rbd_obj_request_put(orig_request);
2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721
	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);

2722 2723
	/*
	 * If the overlap has become 0 (most likely because the
2724 2725
	 * image has been flattened) we need to re-submit the
	 * original request.
2726 2727 2728
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2729 2730
		rbd_obj_request_submit(orig_request);
		return;
2731
	}
2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742

	/*
	 * 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);
2743 2744
	} else {
		goto fail_orig_request;
2745 2746 2747 2748 2749 2750
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2751 2752 2753 2754 2755 2756 2757
	result = rbd_img_obj_request_submit(orig_request);
	if (result)
		goto fail_orig_request;

	return;

fail_orig_request:
2758
	rbd_obj_request_error(orig_request, result);
2759 2760 2761 2762
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
2763
	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2764
	struct rbd_obj_request *stat_request;
2765
	struct page **pages;
2766 2767 2768 2769
	u32 page_count;
	size_t size;
	int ret;

2770
	stat_request = rbd_obj_request_create(OBJ_REQUEST_PAGES);
2771 2772 2773
	if (!stat_request)
		return -ENOMEM;

2774 2775
	stat_request->object_no = obj_request->object_no;

2776 2777 2778 2779 2780 2781 2782
	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;
	}

2783 2784 2785 2786 2787 2788 2789 2790 2791 2792
	/*
	 * 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);
2793
	pages = ceph_alloc_page_vector(page_count, GFP_NOIO);
2794 2795 2796 2797
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto fail_stat_request;
	}
2798

2799 2800 2801
	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);
2802 2803 2804 2805 2806 2807 2808

	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;

2809 2810
	rbd_obj_request_submit(stat_request);
	return 0;
2811

2812 2813
fail_stat_request:
	rbd_obj_request_put(stat_request);
2814 2815 2816
	return ret;
}

2817
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2818
{
2819 2820
	struct rbd_img_request *img_request = obj_request->img_request;
	struct rbd_device *rbd_dev = img_request->rbd_dev;
2821

2822
	/* Reads */
2823 2824
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2825 2826 2827 2828 2829 2830
		return true;

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

2831
	/*
2832 2833
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2834
	 */
2835 2836
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2837

2838 2839 2840 2841 2842 2843 2844 2845
	/*
	 * 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;

2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858
	/*
	 * 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)
{
2859 2860 2861
	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request_type_valid(obj_request->type));
	rbd_assert(obj_request->img_request);
2862

2863
	if (img_obj_request_simple(obj_request)) {
2864 2865
		rbd_obj_request_submit(obj_request);
		return 0;
2866 2867 2868
	}

	/*
2869 2870 2871 2872
	 * 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.
2873
	 */
2874
	if (obj_request_known_test(obj_request))
2875 2876 2877
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
2878 2879 2880 2881

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
2882 2883 2884
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
2885
	struct rbd_obj_request *next_obj_request;
2886
	int ret = 0;
A
Alex Elder 已提交
2887

A
Alex Elder 已提交
2888
	dout("%s: img %p\n", __func__, img_request);
A
Alex Elder 已提交
2889

2890 2891
	rbd_img_request_get(img_request);
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2892
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
2893
		if (ret)
2894
			goto out_put_ireq;
A
Alex Elder 已提交
2895 2896
	}

2897 2898 2899
out_put_ireq:
	rbd_img_request_put(img_request);
	return ret;
A
Alex Elder 已提交
2900
}
A
Alex Elder 已提交
2901 2902 2903 2904

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
2905 2906
	struct rbd_device *rbd_dev;
	u64 obj_end;
2907 2908
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
2909 2910 2911

	rbd_assert(img_request_child_test(img_request));

2912 2913
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
2914
	obj_request = img_request->obj_request;
2915 2916 2917 2918 2919 2920 2921 2922 2923
	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
2924 2925
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
2926 2927
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
2928 2929
		rbd_obj_request_submit(obj_request);
		return;
2930
	}
A
Alex Elder 已提交
2931

2932
	obj_request->result = img_result;
A
Alex Elder 已提交
2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950
	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
2951

2952
		obj_request->xferred = min(img_xferred, xferred);
A
Alex Elder 已提交
2953
	} else {
2954
		obj_request->xferred = img_xferred;
A
Alex Elder 已提交
2955 2956
	}
out:
A
Alex Elder 已提交
2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968
	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);
2969
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
2970 2971

	/* rbd_read_finish(obj_request, obj_request->length); */
2972
	img_request = rbd_parent_request_create(obj_request,
A
Alex Elder 已提交
2973
						obj_request->img_offset,
2974
						obj_request->length);
A
Alex Elder 已提交
2975 2976 2977 2978
	result = -ENOMEM;
	if (!img_request)
		goto out_err;

2979 2980 2981 2982 2983 2984
	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
2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000
	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
3001

3002
static const struct rbd_client_id rbd_empty_cid;
A
Alex Elder 已提交
3003

3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039
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);
}

3040 3041 3042 3043 3044 3045 3046 3047 3048
static void __rbd_lock(struct rbd_device *rbd_dev, const char *cookie)
{
	struct rbd_client_id cid = rbd_get_cid(rbd_dev);

	strcpy(rbd_dev->lock_cookie, cookie);
	rbd_set_owner_cid(rbd_dev, &cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
}

3049 3050 3051 3052
/*
 * lock_rwsem must be held for write
 */
static int rbd_lock(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3053
{
3054
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3055
	char cookie[32];
3056
	int ret;
A
Alex Elder 已提交
3057

I
Ilya Dryomov 已提交
3058 3059
	WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] != '\0');
3060

3061 3062 3063 3064
	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);
3065
	if (ret)
3066
		return ret;
A
Alex Elder 已提交
3067

3068
	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
3069
	__rbd_lock(rbd_dev, cookie);
3070
	return 0;
A
Alex Elder 已提交
3071 3072
}

3073 3074 3075
/*
 * lock_rwsem must be held for write
 */
I
Ilya Dryomov 已提交
3076
static void rbd_unlock(struct rbd_device *rbd_dev)
3077
{
3078
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3079 3080
	int ret;

I
Ilya Dryomov 已提交
3081 3082
	WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
		rbd_dev->lock_cookie[0] == '\0');
3083

3084
	ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
I
Ilya Dryomov 已提交
3085
			      RBD_LOCK_NAME, rbd_dev->lock_cookie);
I
Ilya Dryomov 已提交
3086 3087
	if (ret && ret != -ENOENT)
		rbd_warn(rbd_dev, "failed to unlock: %d", ret);
3088

I
Ilya Dryomov 已提交
3089 3090
	/* treat errors as the image is unlocked */
	rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
I
Ilya Dryomov 已提交
3091
	rbd_dev->lock_cookie[0] = '\0';
3092 3093
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
3094 3095
}

3096 3097 3098 3099
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)
3100 3101
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3102 3103 3104 3105
	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;
3106

3107
	dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3108

3109 3110 3111 3112 3113
	/* 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);
3114

3115 3116 3117
	return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
				&rbd_dev->header_oloc, buf, buf_size,
				RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3118 3119
}

3120 3121
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
			       enum rbd_notify_op notify_op)
3122
{
3123 3124
	struct page **reply_pages;
	size_t reply_len;
3125

3126 3127 3128
	__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
	ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
3129

3130 3131 3132 3133
static void rbd_notify_acquired_lock(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  acquired_lock_work);
3134

3135
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3136 3137
}

3138
static void rbd_notify_released_lock(struct work_struct *work)
3139
{
3140 3141
	struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
						  released_lock_work);
I
Ilya Dryomov 已提交
3142

3143
	rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3144 3145
}

3146
static int rbd_request_lock(struct rbd_device *rbd_dev)
3147
{
3148 3149 3150
	struct page **reply_pages;
	size_t reply_len;
	bool lock_owner_responded = false;
3151 3152
	int ret;

3153
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3154

3155 3156 3157 3158
	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);
3159
		goto out;
3160
	}
3161

3162 3163 3164 3165
	if (reply_len > 0 && reply_len <= PAGE_SIZE) {
		void *p = page_address(reply_pages[0]);
		void *const end = p + reply_len;
		u32 n;
3166

3167 3168 3169 3170
		ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
		while (n--) {
			u8 struct_v;
			u32 len;
3171

3172 3173
			ceph_decode_need(&p, end, 8 + 8, e_inval);
			p += 8 + 8; /* skip gid and cookie */
3174

3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 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
			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;
3407
	int ret = 0;
3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422

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

	ret = rbd_request_lock(rbd_dev);
	if (ret == -ETIMEDOUT) {
		goto again; /* treat this as a dead client */
I
Ilya Dryomov 已提交
3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434
	} else if (ret == -EROFS) {
		rbd_warn(rbd_dev, "peer will not release lock");
		/*
		 * If this is rbd_add_acquire_lock(), we want to fail
		 * immediately -- reuse BLACKLISTED flag.  Otherwise we
		 * want to block.
		 */
		if (!(rbd_dev->disk->flags & GENHD_FL_UP)) {
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
			/* wake "rbd map --exclusive" process */
			wake_requests(rbd_dev, false);
		}
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
	} 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);
3463
	/*
3464
	 * Ensure that all in-flight IO is flushed.
3465
	 *
3466 3467
	 * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
	 * may be shared with other devices.
3468
	 */
3469 3470 3471 3472 3473 3474 3475 3476 3477
	ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc);
	up_read(&rbd_dev->lock_rwsem);

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

I
Ilya Dryomov 已提交
3478 3479 3480 3481 3482 3483 3484 3485 3486
	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);
3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566
	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);
}

3567 3568 3569 3570 3571 3572
/*
 * Returns result for ResponseMessage to be encoded (<= 0), or 1 if no
 * ResponseMessage is needed.
 */
static int rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
				   void **p)
3573 3574 3575
{
	struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
	struct rbd_client_id cid = { 0 };
3576
	int result = 1;
3577 3578 3579 3580 3581 3582 3583 3584 3585

	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))
3586
		return result;
3587 3588

	down_read(&rbd_dev->lock_rwsem);
3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600
	if (__rbd_is_lock_owner(rbd_dev)) {
		if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED &&
		    rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid))
			goto out_unlock;

		/*
		 * encode ResponseMessage(0) so the peer can detect
		 * a missing owner
		 */
		result = 0;

		if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
I
Ilya Dryomov 已提交
3601 3602 3603 3604 3605 3606 3607 3608 3609
			if (!rbd_dev->opts->exclusive) {
				dout("%s rbd_dev %p queueing unlock_work\n",
				     __func__, rbd_dev);
				queue_work(rbd_dev->task_wq,
					   &rbd_dev->unlock_work);
			} else {
				/* refuse to release the lock */
				result = -EROFS;
			}
3610 3611
		}
	}
3612 3613

out_unlock:
3614
	up_read(&rbd_dev->lock_rwsem);
3615
	return result;
3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635
}

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
3636

3637 3638
	ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
				   &rbd_dev->header_oloc, notify_id, cookie,
3639
				   buf, buf_size);
3640
	if (ret)
3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663
		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;
3664
	u8 struct_v = 0;
3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697
	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:
3698 3699
		ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
		if (ret <= 0)
3700
			rbd_acknowledge_notify_result(rbd_dev, notify_id,
3701
						      cookie, ret);
3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719
		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
3720 3721
}

3722 3723
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);

3724
static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3725
{
3726
	struct rbd_device *rbd_dev = arg;
3727

3728
	rbd_warn(rbd_dev, "encountered watch error: %d", err);
3729

3730 3731 3732 3733
	down_write(&rbd_dev->lock_rwsem);
	rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
	up_write(&rbd_dev->lock_rwsem);

3734 3735 3736 3737
	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;
3738

3739
		queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3740
	}
3741
	mutex_unlock(&rbd_dev->watch_mutex);
3742 3743
}

3744
/*
3745
 * watch_mutex must be locked
3746
 */
3747
static int __rbd_register_watch(struct rbd_device *rbd_dev)
3748 3749
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3750
	struct ceph_osd_linger_request *handle;
3751

3752
	rbd_assert(!rbd_dev->watch_handle);
3753
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3754

3755 3756 3757 3758 3759
	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);
3760

3761
	rbd_dev->watch_handle = handle;
3762 3763 3764
	return 0;
}

3765 3766 3767 3768
/*
 * watch_mutex must be locked
 */
static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3769
{
3770 3771
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	int ret;
3772

3773 3774
	rbd_assert(rbd_dev->watch_handle);
	dout("%s rbd_dev %p\n", __func__, rbd_dev);
3775

3776 3777 3778
	ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
	if (ret)
		rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3779

3780
	rbd_dev->watch_handle = NULL;
3781 3782
}

3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801
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)
3802
{
3803 3804 3805
	dout("%s rbd_dev %p\n", __func__, rbd_dev);

	cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3806 3807 3808 3809
	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);
3810 3811 3812 3813
}

static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
3814
	WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3815 3816 3817 3818 3819 3820 3821
	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
3822 3823

	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3824 3825
}

3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854
/*
 * lock_rwsem must be held for write
 */
static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	char cookie[32];
	int ret;

	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);

	format_lock_cookie(rbd_dev, cookie);
	ret = ceph_cls_set_cookie(osdc, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, RBD_LOCK_NAME,
				  CEPH_CLS_LOCK_EXCLUSIVE, rbd_dev->lock_cookie,
				  RBD_LOCK_TAG, cookie);
	if (ret) {
		if (ret != -EOPNOTSUPP)
			rbd_warn(rbd_dev, "failed to update lock cookie: %d",
				 ret);

		/*
		 * Lock cookie cannot be updated on older OSDs, so do
		 * a manual release and queue an acquire.
		 */
		if (rbd_release_lock(rbd_dev))
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->lock_dwork, 0);
	} else {
3855
		__rbd_lock(rbd_dev, cookie);
3856 3857 3858
	}
}

3859 3860 3861 3862 3863 3864 3865 3866 3867
static void rbd_reregister_watch(struct work_struct *work)
{
	struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
					    struct rbd_device, watch_dwork);
	int ret;

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

	mutex_lock(&rbd_dev->watch_mutex);
3868 3869
	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
		mutex_unlock(&rbd_dev->watch_mutex);
3870
		return;
3871
	}
3872 3873 3874 3875

	ret = __rbd_register_watch(rbd_dev);
	if (ret) {
		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3876
		if (ret == -EBLACKLISTED || ret == -ENOENT) {
3877
			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
3878
			wake_requests(rbd_dev, true);
3879
		} else {
3880 3881 3882
			queue_delayed_work(rbd_dev->task_wq,
					   &rbd_dev->watch_dwork,
					   RBD_RETRY_DELAY);
3883 3884
		}
		mutex_unlock(&rbd_dev->watch_mutex);
3885
		return;
3886 3887 3888 3889 3890 3891
	}

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

3892 3893 3894 3895 3896
	down_write(&rbd_dev->lock_rwsem);
	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
		rbd_reacquire_lock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);

3897 3898 3899 3900 3901
	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
		rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
}

3902
/*
3903 3904
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3905 3906
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3907 3908
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
3909
			     const char *method_name,
3910
			     const void *outbound,
3911
			     size_t outbound_size,
3912
			     void *inbound,
3913
			     size_t inbound_size)
3914
{
3915 3916 3917
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct page *req_page = NULL;
	struct page *reply_page;
3918 3919 3920
	int ret;

	/*
3921 3922 3923 3924 3925
	 * 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.
3926
	 */
3927 3928 3929
	if (outbound) {
		if (outbound_size > PAGE_SIZE)
			return -E2BIG;
3930

3931 3932 3933
		req_page = alloc_page(GFP_KERNEL);
		if (!req_page)
			return -ENOMEM;
3934

3935
		memcpy(page_address(req_page), outbound, outbound_size);
3936
	}
3937

3938 3939 3940 3941 3942 3943
	reply_page = alloc_page(GFP_KERNEL);
	if (!reply_page) {
		if (req_page)
			__free_page(req_page);
		return -ENOMEM;
	}
3944

3945 3946 3947 3948 3949 3950 3951
	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;
	}
3952

3953 3954 3955
	if (req_page)
		__free_page(req_page);
	__free_page(reply_page);
3956 3957 3958
	return ret;
}

3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977
/*
 * 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);
3978 3979 3980
	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

3981 3982 3983
	finish_wait(&rbd_dev->lock_waitq, &wait);
}

C
Christoph Hellwig 已提交
3984
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
3985
{
C
Christoph Hellwig 已提交
3986 3987
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
3988
	struct rbd_img_request *img_request;
3989
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
3990 3991
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
3992
	enum obj_operation_type op_type;
3993
	u64 mapping_size;
I
Ilya Dryomov 已提交
3994
	bool must_be_locked;
A
Alex Elder 已提交
3995 3996
	int result;

3997 3998
	switch (req_op(rq)) {
	case REQ_OP_DISCARD:
3999
	case REQ_OP_WRITE_ZEROES:
4000
		op_type = OBJ_OP_DISCARD;
4001 4002
		break;
	case REQ_OP_WRITE:
G
Guangliang Zhao 已提交
4003
		op_type = OBJ_OP_WRITE;
4004 4005
		break;
	case REQ_OP_READ:
G
Guangliang Zhao 已提交
4006
		op_type = OBJ_OP_READ;
4007 4008 4009 4010 4011 4012
		break;
	default:
		dout("%s: non-fs request type %d\n", __func__, req_op(rq));
		result = -EIO;
		goto err;
	}
G
Guangliang Zhao 已提交
4013

I
Ilya Dryomov 已提交
4014
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
4015

I
Ilya Dryomov 已提交
4016 4017 4018 4019 4020
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
4021

4022 4023
	rbd_assert(op_type == OBJ_OP_READ ||
		   rbd_dev->spec->snap_id == CEPH_NOSNAP);
A
Alex Elder 已提交
4024

I
Ilya Dryomov 已提交
4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036
	/*
	 * 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
4037

I
Ilya Dryomov 已提交
4038 4039 4040 4041 4042 4043
	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
4044

C
Christoph Hellwig 已提交
4045 4046
	blk_mq_start_request(rq);

4047 4048
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
4049
	if (op_type != OBJ_OP_READ) {
4050 4051 4052 4053 4054 4055
		snapc = rbd_dev->header.snapc;
		ceph_get_snap_context(snapc);
	}
	up_read(&rbd_dev->header_rwsem);

	if (offset + length > mapping_size) {
I
Ilya Dryomov 已提交
4056
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4057
			 length, mapping_size);
I
Ilya Dryomov 已提交
4058 4059 4060
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
4061

I
Ilya Dryomov 已提交
4062 4063 4064
	must_be_locked =
	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
4065 4066
	if (must_be_locked) {
		down_read(&rbd_dev->lock_rwsem);
4067
		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
I
Ilya Dryomov 已提交
4068 4069 4070 4071 4072 4073
		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			if (rbd_dev->opts->exclusive) {
				rbd_warn(rbd_dev, "exclusive lock required");
				result = -EROFS;
				goto err_unlock;
			}
4074
			rbd_wait_state_locked(rbd_dev);
I
Ilya Dryomov 已提交
4075
		}
4076 4077 4078 4079
		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
			result = -EBLACKLISTED;
			goto err_unlock;
		}
4080 4081
	}

G
Guangliang Zhao 已提交
4082
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4083
					     snapc);
I
Ilya Dryomov 已提交
4084 4085
	if (!img_request) {
		result = -ENOMEM;
4086
		goto err_unlock;
I
Ilya Dryomov 已提交
4087 4088
	}
	img_request->rq = rq;
4089
	snapc = NULL; /* img_request consumes a ref */
A
Alex Elder 已提交
4090

4091 4092 4093 4094 4095 4096
	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
4097 4098
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4099

I
Ilya Dryomov 已提交
4100 4101 4102
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
4103

4104 4105
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4106
	return;
A
Alex Elder 已提交
4107

I
Ilya Dryomov 已提交
4108 4109
err_img_request:
	rbd_img_request_put(img_request);
4110 4111 4112
err_unlock:
	if (must_be_locked)
		up_read(&rbd_dev->lock_rwsem);
I
Ilya Dryomov 已提交
4113 4114 4115
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
4116
			 obj_op_name(op_type), length, offset, result);
4117
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
4118
err:
4119
	blk_mq_end_request(rq, errno_to_blk_status(result));
I
Ilya Dryomov 已提交
4120
}
A
Alex Elder 已提交
4121

4122
static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
C
Christoph Hellwig 已提交
4123
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
4124
{
C
Christoph Hellwig 已提交
4125 4126
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
4127

C
Christoph Hellwig 已提交
4128
	queue_work(rbd_wq, work);
4129
	return BLK_STS_OK;
A
Alex Elder 已提交
4130 4131
}

4132 4133
static void rbd_free_disk(struct rbd_device *rbd_dev)
{
4134 4135 4136
	blk_cleanup_queue(rbd_dev->disk->queue);
	blk_mq_free_tag_set(&rbd_dev->tag_set);
	put_disk(rbd_dev->disk);
4137
	rbd_dev->disk = NULL;
4138 4139
}

4140
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4141 4142 4143
			     struct ceph_object_id *oid,
			     struct ceph_object_locator *oloc,
			     void *buf, int buf_len)
4144 4145

{
4146 4147 4148 4149
	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);
4150 4151
	int ret;

4152 4153 4154
	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
	if (!req)
		return -ENOMEM;
4155

4156 4157 4158
	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
4159

4160
	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
4161
	if (ret)
4162
		goto out_req;
4163

4164 4165 4166 4167 4168
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
	if (IS_ERR(pages)) {
		ret = PTR_ERR(pages);
		goto out_req;
	}
4169

4170 4171 4172 4173 4174 4175 4176 4177
	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);
4178

4179 4180
out_req:
	ceph_osdc_put_request(req);
4181 4182 4183
	return ret;
}

4184
/*
A
Alex Elder 已提交
4185 4186 4187
 * 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.
4188
 */
4189
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4190
{
4191
	struct rbd_image_header_ondisk *ondisk = NULL;
4192
	u32 snap_count = 0;
4193 4194 4195
	u64 names_size = 0;
	u32 want_count;
	int ret;
4196

A
Alex Elder 已提交
4197
	/*
4198 4199 4200 4201 4202
	 * 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
4203
	 */
4204 4205 4206 4207 4208 4209 4210 4211 4212 4213
	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
4214
			return -ENOMEM;
4215

4216 4217
		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
					&rbd_dev->header_oloc, ondisk, size);
4218
		if (ret < 0)
A
Alex Elder 已提交
4219
			goto out;
A
Alex Elder 已提交
4220
		if ((size_t)ret < size) {
4221
			ret = -ENXIO;
A
Alex Elder 已提交
4222 4223
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
4224
			goto out;
4225 4226 4227
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
4228
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
4229
			goto out;
4230
		}
4231

4232 4233 4234 4235
		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
4236

A
Alex Elder 已提交
4237 4238
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
4239 4240 4241
	kfree(ondisk);

	return ret;
4242 4243
}

4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262
/*
 * 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);
}

4263 4264 4265 4266 4267
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;

	/*
I
Ilya Dryomov 已提交
4268 4269 4270
	 * 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.
4271
	 */
I
Ilya Dryomov 已提交
4272 4273
	if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
	    !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4274 4275 4276 4277 4278 4279 4280
		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
4281
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4282
{
4283
	u64 mapping_size;
A
Alex Elder 已提交
4284 4285
	int ret;

4286
	down_write(&rbd_dev->header_rwsem);
4287
	mapping_size = rbd_dev->mapping.size;
4288 4289

	ret = rbd_dev_header_info(rbd_dev);
4290
	if (ret)
4291
		goto out;
4292

4293 4294 4295 4296 4297 4298 4299
	/*
	 * 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)
4300
			goto out;
4301 4302
	}

4303
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4304
		rbd_dev->mapping.size = rbd_dev->header.image_size;
4305 4306 4307 4308
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
4309

4310
out:
4311
	up_write(&rbd_dev->header_rwsem);
4312
	if (!ret && mapping_size != rbd_dev->mapping.size)
4313
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
4314

4315
	return ret;
A
Alex Elder 已提交
4316 4317
}

4318 4319
static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
		unsigned int hctx_idx, unsigned int numa_node)
C
Christoph Hellwig 已提交
4320 4321 4322 4323 4324 4325 4326
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

4327
static const struct blk_mq_ops rbd_mq_ops = {
C
Christoph Hellwig 已提交
4328 4329 4330 4331
	.queue_rq	= rbd_queue_rq,
	.init_request	= rbd_init_request,
};

4332 4333 4334 4335
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
4336
	u64 segment_size;
C
Christoph Hellwig 已提交
4337
	int err;
4338 4339

	/* create gendisk info */
4340 4341 4342
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
4343
	if (!disk)
A
Alex Elder 已提交
4344
		return -ENOMEM;
4345

A
Alex Elder 已提交
4346
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
4347
		 rbd_dev->dev_id);
4348
	disk->major = rbd_dev->major;
4349
	disk->first_minor = rbd_dev->minor;
4350 4351
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
4352 4353 4354
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
4355 4356
	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
4357
	rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
C
Christoph Hellwig 已提交
4358
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
I
Ilya Dryomov 已提交
4359
	rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
C
Christoph Hellwig 已提交
4360 4361 4362 4363 4364
	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)
4365
		goto out_disk;
4366

C
Christoph Hellwig 已提交
4367 4368 4369 4370 4371 4372
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

4373 4374
	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
4375

4376
	/* set io sizes to object size */
A
Alex Elder 已提交
4377 4378
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
4379
	q->limits.max_sectors = queue_max_hw_sectors(q);
4380
	blk_queue_max_segments(q, USHRT_MAX);
A
Alex Elder 已提交
4381 4382 4383
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
4384

4385 4386 4387
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
4388
	blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4389
	blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE);
4390

4391
	if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
4392
		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
4393

4394 4395 4396 4397 4398
	/*
	 * disk_release() expects a queue ref from add_disk() and will
	 * put it.  Hold an extra ref until add_disk() is called.
	 */
	WARN_ON(!blk_get_queue(q));
4399 4400 4401 4402 4403 4404
	disk->queue = q;
	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
4405 4406
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
4407 4408
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
4409
	return err;
4410 4411
}

4412 4413 4414 4415
/*
  sysfs
*/

A
Alex Elder 已提交
4416 4417 4418 4419 4420
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

4421 4422 4423
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4424
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4425

A
Alex Elder 已提交
4426 4427
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
4428 4429
}

A
Alex Elder 已提交
4430 4431 4432 4433 4434 4435 4436 4437 4438 4439
/*
 * 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
4440
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
4441 4442
}

4443 4444 4445
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4446
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4447

A
Alex Elder 已提交
4448 4449 4450 4451
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
4452 4453 4454 4455 4456 4457
}

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
4458

4459
	return sprintf(buf, "%d\n", rbd_dev->minor);
4460 4461
}

4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472
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));
}

4473 4474
static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
4475
{
A
Alex Elder 已提交
4476
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4477

4478
	return sprintf(buf, "client%lld\n",
4479
		       ceph_client_gid(rbd_dev->rbd_client->client));
4480 4481
}

4482 4483 4484 4485 4486 4487 4488 4489
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);
}

4490 4491 4492 4493 4494 4495
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);
4496 4497
}

4498 4499
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
4500
{
A
Alex Elder 已提交
4501
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4502

4503
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4504 4505
}

4506 4507 4508 4509 4510
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);

4511
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
4512
			(unsigned long long) rbd_dev->spec->pool_id);
4513 4514
}

4515 4516 4517
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
4518
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4519

A
Alex Elder 已提交
4520 4521 4522 4523
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
4524 4525
}

A
Alex Elder 已提交
4526 4527 4528 4529 4530
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);

4531
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
4532 4533
}

A
Alex Elder 已提交
4534 4535 4536 4537
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
4538 4539 4540 4541
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
4542
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4543

4544
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4545 4546
}

4547 4548 4549 4550 4551 4552 4553 4554
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);
}

4555
/*
4556 4557 4558
 * 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)".
4559 4560
 */
static ssize_t rbd_parent_show(struct device *dev,
4561 4562
			       struct device_attribute *attr,
			       char *buf)
4563 4564
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4565
	ssize_t count = 0;
4566

4567
	if (!rbd_dev->parent)
4568 4569
		return sprintf(buf, "(no parent image)\n");

4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585
	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;
4586 4587
}

4588 4589 4590 4591 4592
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
4593
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4594
	int ret;
4595

A
Alex Elder 已提交
4596
	ret = rbd_dev_refresh(rbd_dev);
4597
	if (ret)
4598
		return ret;
4599

4600
	return size;
4601
}
4602

4603
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
4604
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4605
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4606
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4607
static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4608
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4609
static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4610
static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4611
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4612
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4613
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
4614
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4615 4616
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4617
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4618
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4619 4620 4621

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
4622
	&dev_attr_features.attr,
4623
	&dev_attr_major.attr,
4624
	&dev_attr_minor.attr,
4625
	&dev_attr_client_addr.attr,
4626
	&dev_attr_client_id.attr,
4627
	&dev_attr_cluster_fsid.attr,
4628
	&dev_attr_config_info.attr,
4629
	&dev_attr_pool.attr,
4630
	&dev_attr_pool_id.attr,
4631
	&dev_attr_name.attr,
A
Alex Elder 已提交
4632
	&dev_attr_image_id.attr,
4633
	&dev_attr_current_snap.attr,
4634
	&dev_attr_snap_id.attr,
4635
	&dev_attr_parent.attr,
4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648
	&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
};

4649
static void rbd_dev_release(struct device *dev);
4650

4651
static const struct device_type rbd_device_type = {
4652 4653
	.name		= "rbd",
	.groups		= rbd_attr_groups,
4654
	.release	= rbd_dev_release,
4655 4656
};

4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677
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;
4678 4679 4680

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696
	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);
}

4697
static void rbd_dev_free(struct rbd_device *rbd_dev)
4698
{
4699
	WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4700
	WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4701

4702
	ceph_oid_destroy(&rbd_dev->header_oid);
4703
	ceph_oloc_destroy(&rbd_dev->header_oloc);
4704
	kfree(rbd_dev->config_info);
4705

4706 4707 4708 4709
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev->opts);
	kfree(rbd_dev);
4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722
}

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);
4723 4724 4725 4726 4727 4728 4729 4730 4731 4732

	/*
	 * 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);
}

4733 4734
static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
					   struct rbd_spec *spec)
4735 4736 4737
{
	struct rbd_device *rbd_dev;

4738
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4739 4740 4741 4742 4743 4744 4745
	if (!rbd_dev)
		return NULL;

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

4746
	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
4747
	ceph_oid_init(&rbd_dev->header_oid);
4748
	rbd_dev->header_oloc.pool = spec->pool_id;
4749

4750 4751 4752 4753
	mutex_init(&rbd_dev->watch_mutex);
	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
	INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);

4754 4755 4756 4757 4758 4759 4760 4761
	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);

4762 4763 4764 4765 4766
	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);

4767
	rbd_dev->rbd_client = rbdc;
4768
	rbd_dev->spec = spec;
4769

4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799
	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;
4800

4801 4802
	/* we have a ref from do_rbd_add() */
	__module_get(THIS_MODULE);
4803

4804
	dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4805
	return rbd_dev;
4806 4807 4808 4809 4810 4811

fail_dev_id:
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
fail_rbd_dev:
	rbd_dev_free(rbd_dev);
	return NULL;
4812 4813 4814 4815
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
4816 4817
	if (rbd_dev)
		put_device(&rbd_dev->dev);
4818 4819
}

4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834
/*
 * 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 };

4835 4836 4837 4838
	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));
4839
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4840 4841
	if (ret < 0)
		return ret;
4842 4843
	if (ret < sizeof (size_buf))
		return -ERANGE;
4844

J
Josh Durgin 已提交
4845
	if (order) {
4846
		*order = size_buf.order;
J
Josh Durgin 已提交
4847 4848
		dout("  order %u", (unsigned int)*order);
	}
4849 4850
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4851 4852
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4853
		(unsigned long long)*snap_size);
4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864

	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);
}

4865 4866 4867 4868 4869 4870 4871 4872 4873 4874
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;

4875 4876 4877
	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);
4878
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4879 4880 4881 4882 4883
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4884 4885
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898

	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;
}

4899 4900 4901 4902 4903 4904 4905
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;
4906
	} __attribute__ ((packed)) features_buf = { 0 };
4907
	u64 unsup;
4908 4909
	int ret;

4910 4911 4912 4913
	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));
4914
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4915 4916
	if (ret < 0)
		return ret;
4917 4918
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4919

4920 4921 4922 4923
	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
4924
		return -ENXIO;
4925
	}
A
Alex Elder 已提交
4926

4927 4928 4929
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4930 4931 4932
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4933 4934 4935 4936 4937 4938 4939 4940 4941 4942

	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);
}

4943 4944 4945 4946 4947 4948 4949 4950
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
4951
	u64 pool_id;
4952
	char *image_id;
4953
	u64 snap_id;
4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970
	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;
	}

4971
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4972 4973 4974
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_parent",
				  &snapid, sizeof(snapid), reply_buf, size);
4975
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4976 4977 4978 4979
	if (ret < 0)
		goto out_err;

	p = reply_buf;
4980 4981
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
4982
	ceph_decode_64_safe(&p, end, pool_id, out_err);
4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999
	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);
		}

5000
		goto out;	/* No parent?  No problem. */
5001
	}
5002

5003 5004 5005
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
5006
	if (pool_id > (u64)U32_MAX) {
5007
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
5008
			(unsigned long long)pool_id, U32_MAX);
5009
		goto out_err;
A
Alex Elder 已提交
5010
	}
5011

A
Alex Elder 已提交
5012
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5013 5014 5015 5016
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
5017
	ceph_decode_64_safe(&p, end, snap_id, out_err);
5018 5019
	ceph_decode_64_safe(&p, end, overlap, out_err);

5020 5021 5022 5023 5024 5025 5026 5027 5028
	/*
	 * 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
5029 5030
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
5031 5032
	} else {
		kfree(image_id);
5033 5034 5035
	}

	/*
5036 5037
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
5038 5039 5040
	 */
	if (!overlap) {
		if (parent_spec) {
5041 5042 5043 5044
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
5045
		} else {
5046 5047
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5048
		}
A
Alex Elder 已提交
5049
	}
5050 5051
	rbd_dev->parent_overlap = overlap;

5052 5053 5054 5055 5056 5057 5058 5059 5060
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

5061 5062 5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 5073
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;

5074 5075 5076
	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);
5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089
	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
5090
	obj_size = rbd_obj_bytes(&rbd_dev->header);
5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104
	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;
	}
5105 5106
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
5107 5108 5109 5110

	return 0;
}

5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128
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;
}

5129 5130
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
5131
	CEPH_DEFINE_OID_ONSTACK(oid);
5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143
	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
5144 5145
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
5146 5147 5148 5149 5150
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
5151
	end = image_id + image_id_size;
5152
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5153 5154 5155 5156 5157 5158

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

5159 5160 5161 5162
	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);
5163 5164 5165
	if (ret < 0)
		goto out;
	p = reply_buf;
5166 5167
	end = reply_buf + ret;

5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179
	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;
}

5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209
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);
5210 5211 5212 5213 5214 5215 5216
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234
		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);
}

5235
/*
5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262
 * 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.
5263
 *
5264 5265
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
5266
 */
5267
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5268
{
5269 5270 5271 5272 5273
	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;
5274 5275
	int ret;

5276 5277 5278
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
5279

5280
	/* Get the pool name; we have to make our own copy of this */
5281

5282 5283 5284
	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);
5285 5286
		return -EIO;
	}
5287 5288
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
5289 5290 5291 5292
		return -ENOMEM;

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

5293 5294
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
5295
		rbd_warn(rbd_dev, "unable to get image name");
5296

5297
	/* Fetch the snapshot name */
5298

5299
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5300 5301
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
5302
		goto out_err;
5303 5304 5305 5306 5307
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
5308 5309

	return 0;
5310

5311
out_err:
5312 5313
	kfree(image_name);
	kfree(pool_name);
5314 5315 5316
	return ret;
}

A
Alex Elder 已提交
5317
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5318 5319 5320 5321 5322 5323 5324 5325 5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337 5338 5339 5340
{
	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;

5341 5342 5343
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapcontext",
				  NULL, 0, reply_buf, size);
5344
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5345 5346 5347 5348
	if (ret < 0)
		goto out;

	p = reply_buf;
5349 5350
	end = reply_buf + ret;
	ret = -ERANGE;
5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366
	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;
5367
	ret = 0;
5368

5369
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5370 5371 5372 5373 5374 5375 5376 5377
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

5378
	ceph_put_snap_context(rbd_dev->header.snapc);
5379 5380 5381
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
5382
		(unsigned long long)seq, (unsigned int)snap_count);
5383 5384 5385
out:
	kfree(reply_buf);

5386
	return ret;
5387 5388
}

5389 5390
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
5391 5392 5393
{
	size_t size;
	void *reply_buf;
5394
	__le64 snapid;
A
Alex Elder 已提交
5395 5396 5397 5398 5399 5400 5401 5402 5403 5404
	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);

5405
	snapid = cpu_to_le64(snap_id);
5406 5407 5408
	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
				  &rbd_dev->header_oloc, "get_snapshot_name",
				  &snapid, sizeof(snapid), reply_buf, size);
5409
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5410 5411
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
5412
		goto out;
5413
	}
A
Alex Elder 已提交
5414 5415

	p = reply_buf;
5416
	end = reply_buf + ret;
A
Alex Elder 已提交
5417
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5418
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
5419 5420
		goto out;

5421
	dout("  snap_id 0x%016llx snap_name = %s\n",
5422
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
5423 5424 5425
out:
	kfree(reply_buf);

5426
	return snap_name;
A
Alex Elder 已提交
5427 5428
}

5429
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5430
{
5431
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
5432 5433
	int ret;

5434 5435
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
5436
		return ret;
5437

5438 5439 5440
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
5441
			return ret;
5442 5443
	}

A
Alex Elder 已提交
5444
	ret = rbd_dev_v2_snap_context(rbd_dev);
5445 5446 5447 5448
	if (ret && first_time) {
		kfree(rbd_dev->header.object_prefix);
		rbd_dev->header.object_prefix = NULL;
	}
A
Alex Elder 已提交
5449 5450 5451 5452

	return ret;
}

5453 5454 5455 5456 5457 5458 5459 5460 5461 5462
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);
}

5463 5464 5465
/*
 * 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
5466 5467
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481
 */
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
5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503
/*
 * 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
5504
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
5505 5506 5507 5508 5509 5510 5511 5512 5513 5514 5515
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

5516
/*
5517 5518 5519 5520
 * 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
5521
 *
5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555
 * 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.
5556
 */
5557
static int rbd_add_parse_args(const char *buf,
5558
				struct ceph_options **ceph_opts,
5559 5560
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
5561
{
A
Alex Elder 已提交
5562
	size_t len;
5563
	char *options;
5564
	const char *mon_addrs;
5565
	char *snap_name;
5566
	size_t mon_addrs_size;
5567
	struct rbd_spec *spec = NULL;
5568
	struct rbd_options *rbd_opts = NULL;
5569
	struct ceph_options *copts;
5570
	int ret;
5571 5572 5573

	/* The first four tokens are required */

5574
	len = next_token(&buf);
5575 5576 5577 5578
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
5579
	mon_addrs = buf;
5580
	mon_addrs_size = len + 1;
5581
	buf += len;
5582

5583
	ret = -EINVAL;
5584 5585
	options = dup_token(&buf, NULL);
	if (!options)
5586
		return -ENOMEM;
5587 5588 5589 5590
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
5591

5592 5593
	spec = rbd_spec_alloc();
	if (!spec)
5594
		goto out_mem;
5595 5596 5597 5598

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
5599 5600 5601 5602
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
5603

A
Alex Elder 已提交
5604
	spec->image_name = dup_token(&buf, NULL);
5605
	if (!spec->image_name)
5606
		goto out_mem;
5607 5608 5609 5610
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
5611

5612 5613 5614 5615
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
5616
	len = next_token(&buf);
5617
	if (!len) {
5618 5619
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5620
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
5621
		ret = -ENAMETOOLONG;
5622
		goto out_err;
5623
	}
5624 5625
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
5626
		goto out_mem;
5627 5628
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
5629

5630
	/* Initialize all rbd options to the defaults */
5631

5632 5633 5634 5635 5636
	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
5637
	rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
I
Ilya Dryomov 已提交
5638
	rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
I
Ilya Dryomov 已提交
5639
	rbd_opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
A
Alex Elder 已提交
5640

5641
	copts = ceph_parse_options(options, mon_addrs,
5642
					mon_addrs + mon_addrs_size - 1,
5643
					parse_rbd_opts_token, rbd_opts);
5644 5645
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
5646 5647
		goto out_err;
	}
5648 5649 5650
	kfree(options);

	*ceph_opts = copts;
5651
	*opts = rbd_opts;
5652
	*rbd_spec = spec;
5653

5654
	return 0;
5655
out_mem:
5656
	ret = -ENOMEM;
A
Alex Elder 已提交
5657
out_err:
5658 5659
	kfree(rbd_opts);
	rbd_spec_put(spec);
5660
	kfree(options);
A
Alex Elder 已提交
5661

5662
	return ret;
5663 5664
}

5665 5666 5667 5668 5669
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
5670
	struct ceph_options *opts = rbdc->client->options;
5671 5672 5673 5674 5675 5676 5677
	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) {
5678 5679
		ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
					    &newest_epoch);
5680 5681 5682 5683
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5684
			ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5685
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5686 5687
						     newest_epoch,
						     opts->mount_timeout);
5688 5689 5690 5691 5692 5693 5694 5695 5696 5697
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

I
Ilya Dryomov 已提交
5698 5699 5700 5701 5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724
static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
{
	down_write(&rbd_dev->lock_rwsem);
	if (__rbd_is_lock_owner(rbd_dev))
		rbd_unlock(rbd_dev);
	up_write(&rbd_dev->lock_rwsem);
}

static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
{
	if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
		rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
		return -EINVAL;
	}

	/* FIXME: "rbd map --exclusive" should be in interruptible */
	down_read(&rbd_dev->lock_rwsem);
	rbd_wait_state_locked(rbd_dev);
	up_read(&rbd_dev->lock_rwsem);
	if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
		rbd_warn(rbd_dev, "failed to acquire exclusive lock");
		return -EROFS;
	}

	return 0;
}

A
Alex Elder 已提交
5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742
/*
 * 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;
5743
	CEPH_DEFINE_OID_ONSTACK(oid);
A
Alex Elder 已提交
5744
	void *response;
5745
	char *image_id;
5746

A
Alex Elder 已提交
5747 5748 5749
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5750 5751
	 * 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
5752
	 */
5753 5754 5755
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5756
		return 0;
5757
	}
A
Alex Elder 已提交
5758

A
Alex Elder 已提交
5759 5760 5761 5762
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
5763 5764 5765 5766 5767 5768
	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
5769 5770 5771 5772 5773 5774 5775 5776 5777 5778

	/* 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;
	}

5779 5780
	/* If it doesn't exist we'll assume it's a format 1 image */

5781 5782 5783
	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
				  "get_id", NULL, 0,
				  response, RBD_IMAGE_ID_LEN_MAX);
5784
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5785 5786 5787 5788 5789
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5790
	} else if (ret >= 0) {
5791 5792 5793
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5794
						NULL, GFP_NOIO);
5795
		ret = PTR_ERR_OR_ZERO(image_id);
5796 5797 5798 5799 5800 5801 5802
		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
5803 5804 5805
	}
out:
	kfree(response);
5806
	ceph_oid_destroy(&oid);
A
Alex Elder 已提交
5807 5808 5809
	return ret;
}

A
Alex Elder 已提交
5810 5811 5812 5813
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5814 5815 5816 5817
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5818
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5819 5820 5821 5822

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

	header = &rbd_dev->header;
5823
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5824 5825 5826 5827 5828 5829
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5830
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5831 5832 5833
{
	int ret;

5834
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5835
	if (ret)
5836 5837
		goto out_err;

5838 5839 5840 5841
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5842
	ret = rbd_dev_v2_features(rbd_dev);
5843
	if (ret)
5844
		goto out_err;
5845

5846 5847 5848 5849 5850 5851 5852
	/* 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;
	}
5853

5854 5855 5856 5857 5858 5859
	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
5860
	rbd_init_layout(rbd_dev);
A
Alex Elder 已提交
5861
	return 0;
I
Ilya Dryomov 已提交
5862

5863
out_err:
A
Alex Elder 已提交
5864
	rbd_dev->header.features = 0;
5865 5866
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5867
	return ret;
5868 5869
}

5870 5871 5872 5873 5874 5875
/*
 * @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
5876
{
5877
	struct rbd_device *parent = NULL;
5878 5879 5880 5881 5882
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;

5883 5884 5885 5886 5887 5888
	if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
		pr_info("parent chain is too long (%d)\n", depth);
		ret = -EINVAL;
		goto out_err;
	}

5889
	parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5890 5891
	if (!parent) {
		ret = -ENOMEM;
5892
		goto out_err;
5893 5894 5895 5896 5897 5898 5899 5900
	}

	/*
	 * 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);
5901

5902
	ret = rbd_dev_image_probe(parent, depth);
5903 5904
	if (ret < 0)
		goto out_err;
5905

5906
	rbd_dev->parent = parent;
5907
	atomic_set(&rbd_dev->parent_ref, 1);
5908
	return 0;
5909

5910
out_err:
5911
	rbd_dev_unparent(rbd_dev);
5912
	rbd_dev_destroy(parent);
5913 5914 5915
	return ret;
}

5916 5917 5918 5919 5920 5921 5922 5923 5924
static void rbd_dev_device_release(struct rbd_device *rbd_dev)
{
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
	rbd_dev_mapping_clear(rbd_dev);
	rbd_free_disk(rbd_dev);
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
}

I
Ilya Dryomov 已提交
5925 5926 5927 5928
/*
 * rbd_dev->header_rwsem must be locked for write and will be unlocked
 * upon return.
 */
5929
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5930
{
A
Alex Elder 已提交
5931
	int ret;
A
Alex Elder 已提交
5932

5933
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5934

5935 5936 5937
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
5938
			goto err_out_unlock;
5939 5940 5941 5942 5943 5944 5945

		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
5946 5947 5948 5949 5950 5951 5952

	/* Set up the blkdev mapping. */

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

5953
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5954 5955
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5956

5957
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5958
	set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only);
5959

5960
	ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
5961
	if (ret)
5962
		goto err_out_mapping;
A
Alex Elder 已提交
5963

5964
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
I
Ilya Dryomov 已提交
5965
	up_write(&rbd_dev->header_rwsem);
5966
	return 0;
5967

5968 5969
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5970 5971 5972
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5973 5974
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
I
Ilya Dryomov 已提交
5975 5976
err_out_unlock:
	up_write(&rbd_dev->header_rwsem);
A
Alex Elder 已提交
5977 5978 5979
	return ret;
}

A
Alex Elder 已提交
5980 5981 5982
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
5983
	int ret;
A
Alex Elder 已提交
5984 5985 5986 5987 5988

	/* 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)
5989 5990
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       spec->image_name, RBD_SUFFIX);
A
Alex Elder 已提交
5991
	else
5992 5993
		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
				       RBD_HEADER_PREFIX, spec->image_id);
A
Alex Elder 已提交
5994

5995
	return ret;
A
Alex Elder 已提交
5996 5997
}

5998 5999
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6000
	rbd_dev_unprobe(rbd_dev);
6001 6002
	if (rbd_dev->opts)
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6003 6004 6005
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6006 6007
}

6008 6009
/*
 * Probe for the existence of the header object for the given rbd
6010 6011 6012
 * 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.
6013
 */
6014
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6015 6016 6017 6018
{
	int ret;

	/*
A
Alex Elder 已提交
6019 6020 6021 6022
	 * 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.
6023 6024 6025
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
6026 6027
		return ret;

A
Alex Elder 已提交
6028 6029 6030 6031
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

6032
	if (!depth) {
6033
		ret = rbd_register_watch(rbd_dev);
6034 6035 6036 6037 6038
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
6039
			goto err_out_format;
6040
		}
6041
	}
6042

6043
	ret = rbd_dev_header_info(rbd_dev);
6044
	if (ret)
6045
		goto err_out_watch;
A
Alex Elder 已提交
6046

6047 6048 6049 6050 6051 6052
	/*
	 * 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.
	 */
6053
	if (!depth)
6054 6055 6056
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
6057 6058 6059 6060 6061 6062
	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
6063
		goto err_out_probe;
6064
	}
6065

6066 6067 6068 6069 6070 6071 6072 6073 6074
	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.
		 */
6075
		if (!depth && rbd_dev->parent_spec)
6076 6077 6078 6079
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

6080
	ret = rbd_dev_probe_parent(rbd_dev, depth);
A
Alex Elder 已提交
6081 6082 6083 6084
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
6085
		rbd_dev->image_format, rbd_dev->header_oid.name);
A
Alex Elder 已提交
6086
	return 0;
6087

A
Alex Elder 已提交
6088 6089
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
6090
err_out_watch:
6091
	if (!depth)
6092
		rbd_unregister_watch(rbd_dev);
A
Alex Elder 已提交
6093 6094
err_out_format:
	rbd_dev->image_format = 0;
6095 6096
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
6097 6098 6099
	return ret;
}

6100 6101 6102
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
6103
{
6104
	struct rbd_device *rbd_dev = NULL;
6105
	struct ceph_options *ceph_opts = NULL;
6106
	struct rbd_options *rbd_opts = NULL;
6107
	struct rbd_spec *spec = NULL;
6108
	struct rbd_client *rbdc;
6109
	int rc;
6110 6111 6112 6113 6114

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

	/* parse add command */
6115
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6116
	if (rc < 0)
6117
		goto out;
6118

6119 6120 6121
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
6122
		goto err_out_args;
6123
	}
6124 6125

	/* pick the pool */
6126
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6127 6128 6129
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
6130
		goto err_out_client;
6131
	}
A
Alex Elder 已提交
6132
	spec->pool_id = (u64)rc;
6133

6134
	rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6135 6136
	if (!rbd_dev) {
		rc = -ENOMEM;
6137
		goto err_out_client;
6138
	}
6139 6140
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
6141
	rbd_opts = NULL;	/* rbd_dev now owns this */
6142

6143 6144 6145 6146 6147 6148
	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
6149
	down_write(&rbd_dev->header_rwsem);
6150
	rc = rbd_dev_image_probe(rbd_dev, 0);
6151 6152
	if (rc < 0) {
		up_write(&rbd_dev->header_rwsem);
6153
		goto err_out_rbd_dev;
6154
	}
6155

6156 6157
	/* If we are mapping a snapshot it must be marked read-only */
	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
6158
		rbd_dev->opts->read_only = true;
6159

6160
	rc = rbd_dev_device_setup(rbd_dev);
6161
	if (rc)
6162
		goto err_out_image_probe;
A
Alex Elder 已提交
6163

I
Ilya Dryomov 已提交
6164 6165 6166 6167
	if (rbd_dev->opts->exclusive) {
		rc = rbd_add_acquire_lock(rbd_dev);
		if (rc)
			goto err_out_device_setup;
A
Alex Elder 已提交
6168 6169
	}

6170 6171 6172 6173
	/* Everything's ready.  Announce the disk to the world. */

	rc = device_add(&rbd_dev->dev);
	if (rc)
I
Ilya Dryomov 已提交
6174
		goto err_out_image_lock;
6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186

	add_disk(rbd_dev->disk);
	/* see rbd_init_disk() */
	blk_put_queue(rbd_dev->disk->queue);

	spin_lock(&rbd_dev_list_lock);
	list_add_tail(&rbd_dev->node, &rbd_dev_list);
	spin_unlock(&rbd_dev_list_lock);

	pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
		(unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
		rbd_dev->header.features);
6187 6188 6189 6190
	rc = count;
out:
	module_put(THIS_MODULE);
	return rc;
6191

I
Ilya Dryomov 已提交
6192 6193
err_out_image_lock:
	rbd_dev_image_unlock(rbd_dev);
6194 6195
err_out_device_setup:
	rbd_dev_device_release(rbd_dev);
6196 6197
err_out_image_probe:
	rbd_dev_image_release(rbd_dev);
6198 6199
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
6200
err_out_client:
6201
	rbd_put_client(rbdc);
6202
err_out_args:
6203
	rbd_spec_put(spec);
6204
	kfree(rbd_opts);
6205
	goto out;
6206 6207
}

6208 6209 6210 6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224
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);
}

6225 6226
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
6227
	while (rbd_dev->parent) {
6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239
		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
6240
		rbd_assert(second);
6241
		rbd_dev_image_release(second);
6242
		rbd_dev_destroy(second);
A
Alex Elder 已提交
6243 6244 6245 6246
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
6247 6248 6249 6250 6251
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

6252 6253 6254
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
6255 6256
{
	struct rbd_device *rbd_dev = NULL;
6257 6258
	struct list_head *tmp;
	int dev_id;
M
Mike Christie 已提交
6259
	char opt_buf[6];
6260
	bool already = false;
M
Mike Christie 已提交
6261
	bool force = false;
6262
	int ret;
6263

M
Mike Christie 已提交
6264 6265 6266 6267 6268
	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");
6269
		return -EINVAL;
M
Mike Christie 已提交
6270 6271 6272 6273 6274 6275 6276 6277 6278
	}
	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;
		}
	}
6279

6280 6281 6282 6283 6284 6285 6286 6287
	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;
		}
6288
	}
6289 6290
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
M
Mike Christie 已提交
6291
		if (rbd_dev->open_count && !force)
6292 6293
			ret = -EBUSY;
		else
6294 6295
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
6296 6297 6298
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
6299
	if (ret < 0 || already)
6300
		return ret;
6301

M
Mike Christie 已提交
6302 6303 6304 6305 6306 6307 6308 6309 6310
	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);
	}

6311 6312 6313 6314 6315
	del_gendisk(rbd_dev->disk);
	spin_lock(&rbd_dev_list_lock);
	list_del_init(&rbd_dev->node);
	spin_unlock(&rbd_dev_list_lock);
	device_del(&rbd_dev->dev);
6316

I
Ilya Dryomov 已提交
6317
	rbd_dev_image_unlock(rbd_dev);
6318
	rbd_dev_device_release(rbd_dev);
6319
	rbd_dev_image_release(rbd_dev);
6320
	rbd_dev_destroy(rbd_dev);
6321
	return count;
6322 6323
}

6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339 6340
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);
}

6341 6342
/*
 * create control files in sysfs
6343
 * /sys/bus/rbd/...
6344 6345 6346
 */
static int rbd_sysfs_init(void)
{
6347
	int ret;
6348

6349
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
6350
	if (ret < 0)
6351
		return ret;
6352

6353 6354 6355
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
6356 6357 6358 6359 6360 6361

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
6362
	bus_unregister(&rbd_bus_type);
6363
	device_unregister(&rbd_root_dev);
6364 6365
}

6366 6367 6368
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
G
Geliang Tang 已提交
6369
	rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6370 6371 6372 6373
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
G
Geliang Tang 已提交
6374
	rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6375 6376 6377
	if (!rbd_obj_request_cache)
		goto out_err;

6378 6379 6380 6381 6382
	rbd_assert(!rbd_bio_clone);
	rbd_bio_clone = bioset_create(BIO_POOL_SIZE, 0, 0);
	if (!rbd_bio_clone)
		goto out_err_clone;

6383
	return 0;
6384

6385 6386 6387
out_err_clone:
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;
6388
out_err:
6389 6390
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
6391 6392 6393 6394 6395
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
6396 6397 6398 6399
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

6400 6401 6402
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
6403 6404 6405 6406

	rbd_assert(rbd_bio_clone);
	bioset_free(rbd_bio_clone);
	rbd_bio_clone = NULL;
6407 6408
}

A
Alex Elder 已提交
6409
static int __init rbd_init(void)
6410 6411 6412
{
	int rc;

6413 6414 6415 6416
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
6417

6418
	rc = rbd_slab_init();
6419 6420
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
6421

6422 6423
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
6424
	 * rbd devices * queue depth, so leave @max_active at default.
6425 6426 6427 6428 6429 6430 6431
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

6432 6433 6434 6435
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
6436
			goto err_out_wq;
6437 6438 6439
		}
	}

6440 6441
	rc = rbd_sysfs_init();
	if (rc)
6442 6443 6444 6445 6446 6447
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
6448

I
Ilya Dryomov 已提交
6449 6450
	return 0;

6451 6452 6453
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6454 6455
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
6456 6457
err_out_slab:
	rbd_slab_exit();
6458
	return rc;
6459 6460
}

A
Alex Elder 已提交
6461
static void __exit rbd_exit(void)
6462
{
I
Ilya Dryomov 已提交
6463
	ida_destroy(&rbd_dev_id_ida);
6464
	rbd_sysfs_cleanup();
6465 6466
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
6467
	destroy_workqueue(rbd_wq);
6468
	rbd_slab_exit();
6469 6470 6471 6472 6473
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
6474
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6475 6476 6477 6478 6479
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>");

6480
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6481
MODULE_LICENSE("GPL");