rbd.c 146.3 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>
#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_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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/* Feature bits */

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#define RBD_FEATURE_LAYERING	(1<<0)
#define RBD_FEATURE_STRIPINGV2	(1<<1)
#define RBD_FEATURES_ALL \
	    (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
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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.
 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
 * enough to hold all possible device names.
 */
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#define DEV_NAME_LEN		32
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#define MAX_INT_FORMAT_WIDTH	((5 * sizeof (int)) / 2 + 1)
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/*
 * 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;
	__u8 crypt_type;
	__u8 comp_type;
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	u64 stripe_unit;
	u64 stripe_count;
	u64 features;		/* Might be changeable someday? */
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	/* The remaining fields need to be updated occasionally */
	u64 image_size;
	struct ceph_snap_context *snapc;
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	char *snap_names;	/* format 1 only */
	u64 *snap_sizes;	/* format 1 only */
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};

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

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

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

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

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

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

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

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

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

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

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

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

	struct kref		kref;
};

#define for_each_obj_request(ireq, oreq) \
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	list_for_each_entry(oreq, &(ireq)->obj_requests, links)
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#define for_each_obj_request_from(ireq, oreq) \
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	list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
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#define for_each_obj_request_safe(ireq, oreq, n) \
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	list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
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struct rbd_mapping {
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	u64                     size;
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	u64                     features;
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	bool			read_only;
};

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

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

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

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	spinlock_t		lock;		/* queue, flags, open_count */
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	struct rbd_image_header	header;
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	unsigned long		flags;		/* possibly lock protected */
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	struct rbd_spec		*spec;
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	char			*header_name;
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	struct ceph_file_layout	layout;

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	struct ceph_osd_event   *watch_event;
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	struct rbd_obj_request	*watch_request;
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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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/*
 * Flag bits for rbd_dev->flags.  If atomicity is required,
 * rbd_dev->lock is used to protect access.
 *
 * Currently, only the "removing" flag (which is coupled with the
 * "open_count" field) requires atomic access.
 */
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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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};

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

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

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

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static struct workqueue_struct *rbd_wq;

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

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static int rbd_img_request_submit(struct rbd_img_request *img_request);

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

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	return attr->mode;
}

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

static void rbd_root_dev_release(struct device *dev)
{
}

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

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

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

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

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#ifdef RBD_DEBUG
#define rbd_assert(expr)						\
		if (unlikely(!(expr))) {				\
			printk(KERN_ERR "\nAssertion failure in %s() "	\
						"at line %d:\n\n"	\
					"\trbd_assert(%s);\n\n",	\
					__func__, __LINE__, #expr);	\
			BUG();						\
		}
#else /* !RBD_DEBUG */
#  define rbd_assert(expr)	((void) 0)
#endif /* !RBD_DEBUG */
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static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
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static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
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static int rbd_dev_refresh(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
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static int rbd_dev_header_info(struct rbd_device *rbd_dev);
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static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
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static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id);
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static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u8 *order, u64 *snap_size);
static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
		u64 *snap_features);
static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name);
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static int rbd_open(struct block_device *bdev, fmode_t mode)
{
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	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
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	bool removing = false;
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	if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
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		return -EROFS;

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	spin_lock_irq(&rbd_dev->lock);
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	if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
		removing = true;
	else
		rbd_dev->open_count++;
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	spin_unlock_irq(&rbd_dev->lock);
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	if (removing)
		return -ENOENT;

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	(void) get_device(&rbd_dev->dev);
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	return 0;
}

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

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	spin_lock_irq(&rbd_dev->lock);
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	open_count_before = rbd_dev->open_count--;
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	spin_unlock_irq(&rbd_dev->lock);
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	rbd_assert(open_count_before > 0);
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	put_device(&rbd_dev->dev);
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}

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static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
{
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	int ret = 0;
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	int val;
	bool ro;
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	bool ro_changed = false;
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	/* get_user() may sleep, so call it before taking rbd_dev->lock */
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	if (get_user(val, (int __user *)(arg)))
		return -EFAULT;

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

592 593 594 595 596 597 598
	spin_lock_irq(&rbd_dev->lock);
	/* prevent others open this device */
	if (rbd_dev->open_count > 1) {
		ret = -EBUSY;
		goto out;
	}

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599 600
	if (rbd_dev->mapping.read_only != ro) {
		rbd_dev->mapping.read_only = ro;
601
		ro_changed = true;
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	}

604 605 606 607 608 609 610
out:
	spin_unlock_irq(&rbd_dev->lock);
	/* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
	if (ret == 0 && ro_changed)
		set_disk_ro(rbd_dev->disk, ro ? 1 : 0);

	return ret;
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}

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

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

	return ret;
}

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

638 639 640
static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
641
	.release		= rbd_release,
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642 643 644 645
	.ioctl			= rbd_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= rbd_compat_ioctl,
#endif
646 647 648
};

/*
649
 * Initialize an rbd client instance.  Success or not, this function
650
 * consumes ceph_opts.  Caller holds client_mutex.
651
 */
652
static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
653 654 655 656
{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

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657
	dout("%s:\n", __func__);
658 659 660 661 662 663 664
	rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
	if (!rbdc)
		goto out_opt;

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

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665
	rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
666
	if (IS_ERR(rbdc->client))
667
		goto out_rbdc;
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668
	ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
669 670 671

	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
672
		goto out_client;
673

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674
	spin_lock(&rbd_client_list_lock);
675
	list_add_tail(&rbdc->node, &rbd_client_list);
A
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676
	spin_unlock(&rbd_client_list_lock);
677

A
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678
	dout("%s: rbdc %p\n", __func__, rbdc);
679

680
	return rbdc;
681
out_client:
682
	ceph_destroy_client(rbdc->client);
683
out_rbdc:
684 685
	kfree(rbdc);
out_opt:
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686 687
	if (ceph_opts)
		ceph_destroy_options(ceph_opts);
A
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688 689
	dout("%s: error %d\n", __func__, ret);

V
Vasiliy Kulikov 已提交
690
	return ERR_PTR(ret);
691 692
}

693 694 695 696 697 698 699
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
	kref_get(&rbdc->kref);

	return rbdc;
}

700
/*
701 702
 * Find a ceph client with specific addr and configuration.  If
 * found, bump its reference count.
703
 */
704
static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
705 706
{
	struct rbd_client *client_node;
707
	bool found = false;
708

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709
	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
710 711
		return NULL;

712 713 714
	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)) {
715 716
			__rbd_get_client(client_node);

717 718 719 720 721 722 723
			found = true;
			break;
		}
	}
	spin_unlock(&rbd_client_list_lock);

	return found ? client_node : NULL;
724 725
}

726 727 728 729 730 731 732 733
/*
 * mount options
 */
enum {
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
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734 735 736 737
	Opt_read_only,
	Opt_read_write,
	/* Boolean args above */
	Opt_last_bool,
738 739
};

A
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740
static match_table_t rbd_opts_tokens = {
741 742
	/* int args above */
	/* string args above */
A
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743
	{Opt_read_only, "read_only"},
A
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744 745 746 747
	{Opt_read_only, "ro"},		/* Alternate spelling */
	{Opt_read_write, "read_write"},
	{Opt_read_write, "rw"},		/* Alternate spelling */
	/* Boolean args above */
748 749 750
	{-1, NULL}
};

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751 752 753 754 755 756
struct rbd_options {
	bool	read_only;
};

#define RBD_READ_ONLY_DEFAULT	false

757 758
static int parse_rbd_opts_token(char *c, void *private)
{
A
Alex Elder 已提交
759
	struct rbd_options *rbd_opts = private;
760 761 762
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

A
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763
	token = match_token(c, rbd_opts_tokens, argstr);
764 765 766 767 768 769 770 771 772 773 774 775 776 777
	if (token < 0)
		return -EINVAL;

	if (token < Opt_last_int) {
		ret = match_int(&argstr[0], &intval);
		if (ret < 0) {
			pr_err("bad mount option arg (not int) "
			       "at '%s'\n", c);
			return ret;
		}
		dout("got int token %d val %d\n", token, intval);
	} else if (token > Opt_last_int && token < Opt_last_string) {
		dout("got string token %d val %s\n", token,
		     argstr[0].from);
A
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778 779
	} else if (token > Opt_last_string && token < Opt_last_bool) {
		dout("got Boolean token %d\n", token);
780 781 782 783 784
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
A
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785 786 787 788 789 790
	case Opt_read_only:
		rbd_opts->read_only = true;
		break;
	case Opt_read_write:
		rbd_opts->read_only = false;
		break;
791
	default:
A
Alex Elder 已提交
792 793
		rbd_assert(false);
		break;
794 795 796 797
	}
	return 0;
}

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Guangliang Zhao 已提交
798 799 800 801 802 803 804
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";
805 806
	case OBJ_OP_DISCARD:
		return "discard";
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Guangliang Zhao 已提交
807 808 809 810 811
	default:
		return "???";
	}
}

812 813
/*
 * Get a ceph client with specific addr and configuration, if one does
814 815
 * not exist create it.  Either way, ceph_opts is consumed by this
 * function.
816
 */
817
static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
818
{
819
	struct rbd_client *rbdc;
820

821
	mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
822
	rbdc = rbd_client_find(ceph_opts);
823
	if (rbdc)	/* using an existing client */
A
Alex Elder 已提交
824
		ceph_destroy_options(ceph_opts);
825
	else
826
		rbdc = rbd_client_create(ceph_opts);
827
	mutex_unlock(&client_mutex);
828

829
	return rbdc;
830 831 832 833
}

/*
 * Destroy ceph client
A
Alex Elder 已提交
834
 *
A
Alex Elder 已提交
835
 * Caller must hold rbd_client_list_lock.
836 837 838 839 840
 */
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
841
	dout("%s: rbdc %p\n", __func__, rbdc);
842
	spin_lock(&rbd_client_list_lock);
843
	list_del(&rbdc->node);
844
	spin_unlock(&rbd_client_list_lock);
845 846 847 848 849 850 851 852 853

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

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
854
static void rbd_put_client(struct rbd_client *rbdc)
855
{
856 857
	if (rbdc)
		kref_put(&rbdc->kref, rbd_client_release);
858 859
}

860 861 862 863 864
static bool rbd_image_format_valid(u32 image_format)
{
	return image_format == 1 || image_format == 2;
}

865 866
static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
{
867 868 869 870 871 872 873
	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
874 875 876 877 878 879 880 881 882 883
	/* 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;

884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
	/*
	 * 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;
902 903
}

904
/*
905 906
 * Fill an rbd image header with information from the given format 1
 * on-disk header.
907
 */
A
Alex Elder 已提交
908
static int rbd_header_from_disk(struct rbd_device *rbd_dev,
909
				 struct rbd_image_header_ondisk *ondisk)
910
{
A
Alex Elder 已提交
911
	struct rbd_image_header *header = &rbd_dev->header;
912 913 914 915 916
	bool first_time = header->object_prefix == NULL;
	struct ceph_snap_context *snapc;
	char *object_prefix = NULL;
	char *snap_names = NULL;
	u64 *snap_sizes = NULL;
917
	u32 snap_count;
918
	size_t size;
919
	int ret = -ENOMEM;
920
	u32 i;
921

922
	/* Allocate this now to avoid having to handle failure below */
A
Alex Elder 已提交
923

924 925
	if (first_time) {
		size_t len;
926

927 928 929 930 931 932 933 934
		len = strnlen(ondisk->object_prefix,
				sizeof (ondisk->object_prefix));
		object_prefix = kmalloc(len + 1, GFP_KERNEL);
		if (!object_prefix)
			return -ENOMEM;
		memcpy(object_prefix, ondisk->object_prefix, len);
		object_prefix[len] = '\0';
	}
A
Alex Elder 已提交
935

936
	/* Allocate the snapshot context and fill it in */
A
Alex Elder 已提交
937

938 939 940 941 942
	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);
943
	if (snap_count) {
944
		struct rbd_image_snap_ondisk *snaps;
A
Alex Elder 已提交
945 946
		u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);

947
		/* We'll keep a copy of the snapshot names... */
948

949 950 951 952
		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
953 954
			goto out_err;

955
		/* ...as well as the array of their sizes. */
956

957
		size = snap_count * sizeof (*header->snap_sizes);
958 959
		snap_sizes = kmalloc(size, GFP_KERNEL);
		if (!snap_sizes)
A
Alex Elder 已提交
960
			goto out_err;
961

A
Alex Elder 已提交
962
		/*
963 964 965
		 * Copy the names, and fill in each snapshot's id
		 * and size.
		 *
966
		 * Note that rbd_dev_v1_header_info() guarantees the
967
		 * ondisk buffer we're working with has
A
Alex Elder 已提交
968 969 970
		 * snap_names_len bytes beyond the end of the
		 * snapshot id array, this memcpy() is safe.
		 */
971 972 973 974 975 976
		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);
		}
977
	}
A
Alex Elder 已提交
978

979
	/* We won't fail any more, fill in the header */
980

981 982 983 984 985 986 987 988 989
	if (first_time) {
		header->object_prefix = object_prefix;
		header->obj_order = ondisk->options.order;
		header->crypt_type = ondisk->options.crypt_type;
		header->comp_type = ondisk->options.comp_type;
		/* The rest aren't used for format 1 images */
		header->stripe_unit = 0;
		header->stripe_count = 0;
		header->features = 0;
990
	} else {
A
Alex Elder 已提交
991 992 993
		ceph_put_snap_context(header->snapc);
		kfree(header->snap_names);
		kfree(header->snap_sizes);
994
	}
995

996
	/* The remaining fields always get updated (when we refresh) */
997

A
Alex Elder 已提交
998
	header->image_size = le64_to_cpu(ondisk->image_size);
999 1000 1001
	header->snapc = snapc;
	header->snap_names = snap_names;
	header->snap_sizes = snap_sizes;
1002

1003
	return 0;
1004 1005
out_2big:
	ret = -EIO;
A
Alex Elder 已提交
1006
out_err:
1007 1008 1009 1010
	kfree(snap_sizes);
	kfree(snap_names);
	ceph_put_snap_context(snapc);
	kfree(object_prefix);
1011

1012
	return ret;
1013 1014
}

1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029
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);
}

1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053
/*
 * 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.
 */
1054 1055 1056
static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
{
	struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1057
	u64 *found;
1058

1059 1060
	found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
				sizeof (snap_id), snapid_compare_reverse);
1061

1062
	return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1063 1064
}

1065 1066
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
1067
{
1068
	u32 which;
1069
	const char *snap_name;
1070

1071 1072
	which = rbd_dev_snap_index(rbd_dev, snap_id);
	if (which == BAD_SNAP_INDEX)
1073
		return ERR_PTR(-ENOENT);
1074

1075 1076
	snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
	return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1077 1078 1079 1080
}

static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
1081 1082 1083
	if (snap_id == CEPH_NOSNAP)
		return RBD_SNAP_HEAD_NAME;

1084 1085 1086
	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);
1087

1088
	return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1089 1090
}

1091 1092
static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
				u64 *snap_size)
1093
{
1094 1095 1096 1097 1098
	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;
1099

1100 1101 1102
		which = rbd_dev_snap_index(rbd_dev, snap_id);
		if (which == BAD_SNAP_INDEX)
			return -ENOENT;
1103

1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
		*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;
1116 1117
}

1118 1119
static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
			u64 *snap_features)
1120
{
1121 1122 1123 1124 1125
	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 */
1126
	} else {
1127 1128
		u64 features = 0;
		int ret;
1129

1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140
		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)
{
1141
	u64 snap_id = rbd_dev->spec->snap_id;
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155
	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;

1156
	return 0;
1157 1158
}

A
Alex Elder 已提交
1159 1160 1161 1162
static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
{
	rbd_dev->mapping.size = 0;
	rbd_dev->mapping.features = 0;
1163 1164
}

1165 1166 1167 1168 1169 1170 1171
static void rbd_segment_name_free(const char *name)
{
	/* The explicit cast here is needed to drop the const qualifier */

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

A
Alex Elder 已提交
1172
static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1173
{
A
Alex Elder 已提交
1174 1175 1176
	char *name;
	u64 segment;
	int ret;
1177
	char *name_format;
1178

1179
	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
A
Alex Elder 已提交
1180 1181 1182
	if (!name)
		return NULL;
	segment = offset >> rbd_dev->header.obj_order;
1183 1184 1185
	name_format = "%s.%012llx";
	if (rbd_dev->image_format == 2)
		name_format = "%s.%016llx";
1186
	ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
A
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1187
			rbd_dev->header.object_prefix, segment);
1188
	if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
A
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1189 1190
		pr_err("error formatting segment name for #%llu (%d)\n",
			segment, ret);
1191
		rbd_segment_name_free(name);
A
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1192 1193
		name = NULL;
	}
1194

A
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1195 1196
	return name;
}
1197

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static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
{
	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1201

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1202 1203 1204 1205 1206 1207 1208 1209 1210 1211
	return offset & (segment_size - 1);
}

static u64 rbd_segment_length(struct rbd_device *rbd_dev,
				u64 offset, u64 length)
{
	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;

	offset &= segment_size - 1;

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1212
	rbd_assert(length <= U64_MAX - offset);
A
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1213 1214 1215 1216
	if (offset + length > segment_size)
		length = segment_size - offset;

	return length;
1217 1218
}

1219 1220 1221 1222 1223 1224 1225 1226
/*
 * returns the size of an object in the image
 */
static u64 rbd_obj_bytes(struct rbd_image_header *header)
{
	return 1 << header->obj_order;
}

1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
/*
 * 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)
{
1247 1248
	struct bio_vec bv;
	struct bvec_iter iter;
1249 1250 1251 1252 1253
	unsigned long flags;
	void *buf;
	int pos = 0;

	while (chain) {
1254 1255
		bio_for_each_segment(bv, chain, iter) {
			if (pos + bv.bv_len > start_ofs) {
1256
				int remainder = max(start_ofs - pos, 0);
1257
				buf = bvec_kmap_irq(&bv, &flags);
1258
				memset(buf + remainder, 0,
1259 1260
				       bv.bv_len - remainder);
				flush_dcache_page(bv.bv_page);
1261
				bvec_kunmap_irq(buf, &flags);
1262
			}
1263
			pos += bv.bv_len;
1264 1265 1266 1267 1268 1269
		}

		chain = chain->bi_next;
	}
}

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1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287
/*
 * 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;

1288 1289
		page_offset = offset & ~PAGE_MASK;
		length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
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		local_irq_save(flags);
		kaddr = kmap_atomic(*page);
		memset(kaddr + page_offset, 0, length);
1293
		flush_dcache_page(*page);
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		kunmap_atomic(kaddr);
		local_irq_restore(flags);

		offset += length;
		page++;
	}
}

1302
/*
A
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1303 1304
 * Clone a portion of a bio, starting at the given byte offset
 * and continuing for the number of bytes indicated.
1305
 */
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static struct bio *bio_clone_range(struct bio *bio_src,
					unsigned int offset,
					unsigned int len,
					gfp_t gfpmask)
1310
{
A
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1311 1312
	struct bio *bio;

K
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1313
	bio = bio_clone(bio_src, gfpmask);
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1314 1315
	if (!bio)
		return NULL;	/* ENOMEM */
1316

K
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1317
	bio_advance(bio, offset);
1318
	bio->bi_iter.bi_size = len;
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	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 */

1349
	if (!bi || off >= bi->bi_iter.bi_size || !len)
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1350
		return NULL;		/* Nothing to clone */
1351

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1352 1353 1354 1355 1356
	end = &chain;
	while (len) {
		unsigned int bi_size;
		struct bio *bio;

1357 1358
		if (!bi) {
			rbd_warn(NULL, "bio_chain exhausted with %u left", len);
A
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1359
			goto out_err;	/* EINVAL; ran out of bio's */
1360
		}
1361
		bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
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1362 1363 1364 1365 1366 1367
		bio = bio_clone_range(bi, off, bi_size, gfpmask);
		if (!bio)
			goto out_err;	/* ENOMEM */

		*end = bio;
		end = &bio->bi_next;
1368

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1369
		off += bi_size;
1370
		if (off == bi->bi_iter.bi_size) {
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1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381
			bi = bi->bi_next;
			off = 0;
		}
		len -= bi_size;
	}
	*bio_src = bi;
	*offset = off;

	return chain;
out_err:
	bio_chain_put(chain);
1382 1383 1384 1385

	return NULL;
}

1386 1387 1388 1389 1390
/*
 * 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.
 */
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1391
static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1392
{
A
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1393
	if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1394 1395
		struct rbd_device *rbd_dev;

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		rbd_dev = obj_request->img_request->rbd_dev;
1397
		rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1398 1399 1400 1401
			obj_request);
	}
}

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static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1403 1404
{
	smp_mb();
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1405
	return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1406 1407
}

A
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static void obj_request_done_set(struct rbd_obj_request *obj_request)
1409
{
A
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	if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
		struct rbd_device *rbd_dev = NULL;
1412

A
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1413 1414
		if (obj_request_img_data_test(obj_request))
			rbd_dev = obj_request->img_request->rbd_dev;
1415
		rbd_warn(rbd_dev, "obj_request %p already marked done",
1416 1417 1418 1419
			obj_request);
	}
}

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static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1421 1422
{
	smp_mb();
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1423
	return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1424 1425
}

1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
/*
 * 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;
}

1457 1458 1459 1460 1461 1462 1463 1464
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));
}

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static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
A
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	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
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	kref_get(&obj_request->kref);
}

static void rbd_obj_request_destroy(struct kref *kref);
static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
{
	rbd_assert(obj_request != NULL);
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	dout("%s: obj %p (was %d)\n", __func__, obj_request,
		atomic_read(&obj_request->kref.refcount));
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	kref_put(&obj_request->kref, rbd_obj_request_destroy);
}

1481 1482 1483 1484 1485 1486 1487
static void rbd_img_request_get(struct rbd_img_request *img_request)
{
	dout("%s: img %p (was %d)\n", __func__, img_request,
	     atomic_read(&img_request->kref.refcount));
	kref_get(&img_request->kref);
}

1488 1489
static bool img_request_child_test(struct rbd_img_request *img_request);
static void rbd_parent_request_destroy(struct kref *kref);
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static void rbd_img_request_destroy(struct kref *kref);
static void rbd_img_request_put(struct rbd_img_request *img_request)
{
	rbd_assert(img_request != NULL);
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	dout("%s: img %p (was %d)\n", __func__, img_request,
		atomic_read(&img_request->kref.refcount));
1496 1497 1498 1499
	if (img_request_child_test(img_request))
		kref_put(&img_request->kref, rbd_parent_request_destroy);
	else
		kref_put(&img_request->kref, rbd_img_request_destroy);
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}

static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
					struct rbd_obj_request *obj_request)
{
1505 1506
	rbd_assert(obj_request->img_request == NULL);

1507
	/* Image request now owns object's original reference */
A
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1508
	obj_request->img_request = img_request;
1509
	obj_request->which = img_request->obj_request_count;
1510 1511
	rbd_assert(!obj_request_img_data_test(obj_request));
	obj_request_img_data_set(obj_request);
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1512
	rbd_assert(obj_request->which != BAD_WHICH);
1513 1514
	img_request->obj_request_count++;
	list_add_tail(&obj_request->links, &img_request->obj_requests);
A
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1515 1516
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
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1517 1518 1519 1520 1521 1522
}

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);
1523

A
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1524 1525
	dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
		obj_request->which);
A
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1526
	list_del(&obj_request->links);
1527 1528 1529 1530
	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;
1531
	rbd_assert(obj_request_img_data_test(obj_request));
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	rbd_assert(obj_request->img_request == img_request);
	obj_request->img_request = NULL;
1534
	obj_request->callback = NULL;
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	rbd_obj_request_put(obj_request);
}

static bool obj_request_type_valid(enum obj_request_type type)
{
	switch (type) {
1541
	case OBJ_REQUEST_NODATA:
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1542
	case OBJ_REQUEST_BIO:
1543
	case OBJ_REQUEST_PAGES:
A
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1544 1545 1546 1547 1548 1549 1550 1551 1552
		return true;
	default:
		return false;
	}
}

static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
				struct rbd_obj_request *obj_request)
{
1553
	dout("%s %p\n", __func__, obj_request);
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	return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
}

1557 1558 1559 1560 1561 1562 1563 1564 1565
static void rbd_obj_request_end(struct rbd_obj_request *obj_request)
{
	dout("%s %p\n", __func__, obj_request);
	ceph_osdc_cancel_request(obj_request->osd_req);
}

/*
 * Wait for an object request to complete.  If interrupted, cancel the
 * underlying osd request.
1566 1567
 *
 * @timeout: in jiffies, 0 means "wait forever"
1568
 */
1569 1570
static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
				  unsigned long timeout)
1571
{
1572
	long ret;
1573 1574

	dout("%s %p\n", __func__, obj_request);
1575 1576 1577 1578 1579 1580
	ret = wait_for_completion_interruptible_timeout(
					&obj_request->completion,
					ceph_timeout_jiffies(timeout));
	if (ret <= 0) {
		if (ret == 0)
			ret = -ETIMEDOUT;
1581
		rbd_obj_request_end(obj_request);
1582 1583
	} else {
		ret = 0;
1584 1585
	}

1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598
	dout("%s %p ret %d\n", __func__, obj_request, (int)ret);
	return ret;
}

static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
{
	return __rbd_obj_request_wait(obj_request, 0);
}

static int rbd_obj_request_wait_timeout(struct rbd_obj_request *obj_request,
					unsigned long timeout)
{
	return __rbd_obj_request_wait(obj_request, timeout);
1599 1600
}

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1601 1602
static void rbd_img_request_complete(struct rbd_img_request *img_request)
{
1603

A
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1604
	dout("%s: img %p\n", __func__, img_request);
1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620

	/*
	 * 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;
	}

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	if (img_request->callback)
		img_request->callback(img_request);
	else
		rbd_img_request_put(img_request);
}

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1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
/*
 * 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;
}

1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658
/*
 * 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;
}

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

1665 1666 1667 1668 1669 1670
static void img_request_child_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_CHILD, &img_request->flags);
	smp_mb();
}

1671 1672 1673 1674 1675 1676
static bool img_request_child_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
}

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

1683 1684 1685 1686 1687 1688
static void img_request_layered_clear(struct rbd_img_request *img_request)
{
	clear_bit(IMG_REQ_LAYERED, &img_request->flags);
	smp_mb();
}

1689 1690 1691 1692 1693 1694
static bool img_request_layered_test(struct rbd_img_request *img_request)
{
	smp_mb();
	return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
}

1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705
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;
}

1706 1707 1708
static void
rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
{
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	u64 xferred = obj_request->xferred;
	u64 length = obj_request->length;

1712 1713
	dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
		obj_request, obj_request->img_request, obj_request->result,
A
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1714
		xferred, length);
1715
	/*
1716 1717 1718 1719 1720 1721
	 * 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.
1722
	 */
A
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1723
	rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1724
	if (obj_request->result == -ENOENT) {
A
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1725 1726 1727 1728
		if (obj_request->type == OBJ_REQUEST_BIO)
			zero_bio_chain(obj_request->bio_list, 0);
		else
			zero_pages(obj_request->pages, 0, length);
1729
		obj_request->result = 0;
A
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1730 1731 1732 1733 1734
	} 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);
1735
	}
1736
	obj_request->xferred = length;
1737 1738 1739
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1740 1741
static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
{
A
Alex Elder 已提交
1742 1743
	dout("%s: obj %p cb %p\n", __func__, obj_request,
		obj_request->callback);
A
Alex Elder 已提交
1744 1745
	if (obj_request->callback)
		obj_request->callback(obj_request);
1746 1747
	else
		complete_all(&obj_request->completion);
A
Alex Elder 已提交
1748 1749
}

1750
static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1751 1752 1753 1754 1755
{
	dout("%s: obj %p\n", __func__, obj_request);
	obj_request_done_set(obj_request);
}

1756
static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1757
{
A
Alex Elder 已提交
1758
	struct rbd_img_request *img_request = NULL;
A
Alex Elder 已提交
1759
	struct rbd_device *rbd_dev = NULL;
A
Alex Elder 已提交
1760 1761 1762 1763 1764
	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
1765
		rbd_dev = img_request->rbd_dev;
A
Alex Elder 已提交
1766
	}
A
Alex Elder 已提交
1767 1768 1769 1770

	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
1771 1772
	if (layered && obj_request->result == -ENOENT &&
			obj_request->img_offset < rbd_dev->parent_overlap)
A
Alex Elder 已提交
1773 1774
		rbd_img_parent_read(obj_request);
	else if (img_request)
1775 1776 1777
		rbd_img_obj_request_read_callback(obj_request);
	else
		obj_request_done_set(obj_request);
A
Alex Elder 已提交
1778 1779
}

1780
static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1781
{
1782 1783 1784
	dout("%s: obj %p result %d %llu\n", __func__, obj_request,
		obj_request->result, obj_request->length);
	/*
A
Alex Elder 已提交
1785 1786
	 * There is no such thing as a successful short write.  Set
	 * it to our originally-requested length.
1787 1788
	 */
	obj_request->xferred = obj_request->length;
1789
	obj_request_done_set(obj_request);
A
Alex Elder 已提交
1790 1791
}

1792 1793 1794 1795 1796 1797 1798 1799 1800
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;
1801 1802 1803
	/* discarding a non-existent object is not a problem */
	if (obj_request->result == -ENOENT)
		obj_request->result = 0;
1804 1805 1806
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1807 1808 1809 1810
/*
 * 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.
 */
1811
static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1812
{
A
Alex Elder 已提交
1813
	dout("%s: obj %p\n", __func__, obj_request);
A
Alex Elder 已提交
1814 1815 1816
	obj_request_done_set(obj_request);
}

A
Alex Elder 已提交
1817 1818 1819 1820 1821 1822
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
				struct ceph_msg *msg)
{
	struct rbd_obj_request *obj_request = osd_req->r_priv;
	u16 opcode;

A
Alex Elder 已提交
1823
	dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
A
Alex Elder 已提交
1824
	rbd_assert(osd_req == obj_request->osd_req);
A
Alex Elder 已提交
1825 1826 1827 1828 1829 1830
	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
1831

1832 1833
	if (osd_req->r_result < 0)
		obj_request->result = osd_req->r_result;
A
Alex Elder 已提交
1834

1835
	rbd_assert(osd_req->r_num_ops <= CEPH_OSD_MAX_OP);
A
Alex Elder 已提交
1836

1837 1838
	/*
	 * We support a 64-bit length, but ultimately it has to be
C
Christoph Hellwig 已提交
1839 1840
	 * passed to the block layer, which just supports a 32-bit
	 * length field.
1841
	 */
1842
	obj_request->xferred = osd_req->r_reply_op_len[0];
A
Alex Elder 已提交
1843
	rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1844

1845
	opcode = osd_req->r_ops[0].op;
A
Alex Elder 已提交
1846 1847
	switch (opcode) {
	case CEPH_OSD_OP_READ:
1848
		rbd_osd_read_callback(obj_request);
A
Alex Elder 已提交
1849
		break;
1850 1851 1852
	case CEPH_OSD_OP_SETALLOCHINT:
		rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE);
		/* fall through */
A
Alex Elder 已提交
1853
	case CEPH_OSD_OP_WRITE:
1854
		rbd_osd_write_callback(obj_request);
A
Alex Elder 已提交
1855
		break;
A
Alex Elder 已提交
1856
	case CEPH_OSD_OP_STAT:
1857
		rbd_osd_stat_callback(obj_request);
A
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1858
		break;
1859 1860 1861 1862 1863
	case CEPH_OSD_OP_DELETE:
	case CEPH_OSD_OP_TRUNCATE:
	case CEPH_OSD_OP_ZERO:
		rbd_osd_discard_callback(obj_request);
		break;
1864
	case CEPH_OSD_OP_CALL:
A
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1865
	case CEPH_OSD_OP_NOTIFY_ACK:
1866
	case CEPH_OSD_OP_WATCH:
1867
		rbd_osd_trivial_callback(obj_request);
1868
		break;
A
Alex Elder 已提交
1869
	default:
1870
		rbd_warn(NULL, "%s: unsupported op %hu",
A
Alex Elder 已提交
1871 1872 1873 1874
			obj_request->object_name, (unsigned short) opcode);
		break;
	}

1875
	if (obj_request_done_test(obj_request))
A
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1876 1877 1878
		rbd_obj_request_complete(obj_request);
}

1879
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1880 1881
{
	struct rbd_img_request *img_request = obj_request->img_request;
1882
	struct ceph_osd_request *osd_req = obj_request->osd_req;
1883
	u64 snap_id;
A
Alex Elder 已提交
1884

1885
	rbd_assert(osd_req != NULL);
A
Alex Elder 已提交
1886

1887
	snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1888
	ceph_osdc_build_request(osd_req, obj_request->offset,
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903
			NULL, snap_id, NULL);
}

static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request = obj_request->img_request;
	struct ceph_osd_request *osd_req = obj_request->osd_req;
	struct ceph_snap_context *snapc;
	struct timespec mtime = CURRENT_TIME;

	rbd_assert(osd_req != NULL);

	snapc = img_request ? img_request->snapc : NULL;
	ceph_osdc_build_request(osd_req, obj_request->offset,
			snapc, CEPH_NOSNAP, &mtime);
A
Alex Elder 已提交
1904 1905
}

1906 1907 1908 1909 1910 1911
/*
 * 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
1912 1913
static struct ceph_osd_request *rbd_osd_req_create(
					struct rbd_device *rbd_dev,
G
Guangliang Zhao 已提交
1914
					enum obj_operation_type op_type,
1915
					unsigned int num_ops,
A
Alex Elder 已提交
1916
					struct rbd_obj_request *obj_request)
A
Alex Elder 已提交
1917 1918 1919 1920 1921
{
	struct ceph_snap_context *snapc = NULL;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;

1922 1923
	if (obj_request_img_data_test(obj_request) &&
		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1924
		struct rbd_img_request *img_request = obj_request->img_request;
1925 1926 1927 1928 1929
		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
1930
		snapc = img_request->snapc;
A
Alex Elder 已提交
1931 1932
	}

G
Guangliang Zhao 已提交
1933
	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1934 1935

	/* Allocate and initialize the request, for the num_ops ops */
A
Alex Elder 已提交
1936 1937

	osdc = &rbd_dev->rbd_client->client->osdc;
1938 1939
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
					  GFP_ATOMIC);
A
Alex Elder 已提交
1940 1941 1942
	if (!osd_req)
		return NULL;	/* ENOMEM */

1943
	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
A
Alex Elder 已提交
1944
		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
A
Alex Elder 已提交
1945
	else
A
Alex Elder 已提交
1946 1947 1948 1949 1950
		osd_req->r_flags = CEPH_OSD_FLAG_READ;

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

1951 1952
	osd_req->r_base_oloc.pool = ceph_file_layout_pg_pool(rbd_dev->layout);
	ceph_oid_set_name(&osd_req->r_base_oid, obj_request->object_name);
A
Alex Elder 已提交
1953 1954 1955 1956

	return osd_req;
}

1957
/*
1958 1959 1960 1961
 * 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.
1962 1963 1964 1965 1966 1967 1968 1969 1970
 */
static struct ceph_osd_request *
rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	struct ceph_snap_context *snapc;
	struct rbd_device *rbd_dev;
	struct ceph_osd_client *osdc;
	struct ceph_osd_request *osd_req;
1971
	int num_osd_ops = 3;
1972 1973 1974 1975

	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;
	rbd_assert(img_request);
1976 1977
	rbd_assert(img_request_write_test(img_request) ||
			img_request_discard_test(img_request));
1978

1979 1980 1981 1982
	if (img_request_discard_test(img_request))
		num_osd_ops = 2;

	/* Allocate and initialize the request, for all the ops */
1983 1984 1985 1986

	snapc = img_request->snapc;
	rbd_dev = img_request->rbd_dev;
	osdc = &rbd_dev->rbd_client->client->osdc;
1987 1988
	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
						false, GFP_ATOMIC);
1989 1990 1991 1992 1993 1994 1995
	if (!osd_req)
		return NULL;	/* ENOMEM */

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

1996 1997
	osd_req->r_base_oloc.pool = ceph_file_layout_pg_pool(rbd_dev->layout);
	ceph_oid_set_name(&osd_req->r_base_oid, obj_request->object_name);
1998 1999 2000 2001 2002

	return osd_req;
}


A
Alex Elder 已提交
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
{
	ceph_osdc_put_request(osd_req);
}

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

static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
						u64 offset, u64 length,
						enum obj_request_type type)
{
	struct rbd_obj_request *obj_request;
	size_t size;
	char *name;

	rbd_assert(obj_request_type_valid(type));

	size = strlen(object_name) + 1;
2021 2022
	name = kmalloc(size, GFP_KERNEL);
	if (!name)
A
Alex Elder 已提交
2023 2024
		return NULL;

2025
	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
2026 2027 2028 2029 2030
	if (!obj_request) {
		kfree(name);
		return NULL;
	}

A
Alex Elder 已提交
2031 2032 2033
	obj_request->object_name = memcpy(name, object_name, size);
	obj_request->offset = offset;
	obj_request->length = length;
2034
	obj_request->flags = 0;
A
Alex Elder 已提交
2035 2036 2037
	obj_request->which = BAD_WHICH;
	obj_request->type = type;
	INIT_LIST_HEAD(&obj_request->links);
2038
	init_completion(&obj_request->completion);
A
Alex Elder 已提交
2039 2040
	kref_init(&obj_request->kref);

A
Alex Elder 已提交
2041 2042 2043
	dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
		offset, length, (int)type, obj_request);

A
Alex Elder 已提交
2044 2045 2046 2047 2048 2049 2050 2051 2052
	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
2053 2054
	dout("%s: obj %p\n", __func__, obj_request);

A
Alex Elder 已提交
2055 2056 2057 2058 2059 2060 2061 2062
	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) {
2063 2064
	case OBJ_REQUEST_NODATA:
		break;		/* Nothing to do */
A
Alex Elder 已提交
2065 2066 2067 2068
	case OBJ_REQUEST_BIO:
		if (obj_request->bio_list)
			bio_chain_put(obj_request->bio_list);
		break;
2069 2070 2071 2072 2073
	case OBJ_REQUEST_PAGES:
		if (obj_request->pages)
			ceph_release_page_vector(obj_request->pages,
						obj_request->page_count);
		break;
A
Alex Elder 已提交
2074 2075
	}

2076
	kfree(obj_request->object_name);
2077 2078
	obj_request->object_name = NULL;
	kmem_cache_free(rbd_obj_request_cache, obj_request);
A
Alex Elder 已提交
2079 2080
}

A
Alex Elder 已提交
2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091
/* 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;
}

2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113
/*
 * 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
2114
		rbd_warn(rbd_dev, "parent reference underflow");
2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126
}

/*
 * 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)
{
2127
	int counter = 0;
2128 2129 2130 2131

	if (!rbd_dev->parent_spec)
		return false;

2132 2133 2134 2135
	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);
2136 2137

	if (counter < 0)
2138
		rbd_warn(rbd_dev, "parent reference overflow");
2139

2140
	return counter > 0;
2141 2142
}

A
Alex Elder 已提交
2143 2144 2145 2146 2147
/*
 * 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
2148 2149
static struct rbd_img_request *rbd_img_request_create(
					struct rbd_device *rbd_dev,
A
Alex Elder 已提交
2150
					u64 offset, u64 length,
G
Guangliang Zhao 已提交
2151
					enum obj_operation_type op_type,
2152
					struct ceph_snap_context *snapc)
A
Alex Elder 已提交
2153 2154 2155
{
	struct rbd_img_request *img_request;

2156
	img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
A
Alex Elder 已提交
2157 2158 2159 2160 2161 2162 2163
	if (!img_request)
		return NULL;

	img_request->rq = NULL;
	img_request->rbd_dev = rbd_dev;
	img_request->offset = offset;
	img_request->length = length;
A
Alex Elder 已提交
2164
	img_request->flags = 0;
2165 2166 2167 2168
	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
2169
		img_request_write_set(img_request);
2170
		img_request->snapc = snapc;
A
Alex Elder 已提交
2171
	} else {
A
Alex Elder 已提交
2172
		img_request->snap_id = rbd_dev->spec->snap_id;
A
Alex Elder 已提交
2173
	}
2174
	if (rbd_dev_parent_get(rbd_dev))
2175
		img_request_layered_set(img_request);
A
Alex Elder 已提交
2176 2177 2178
	spin_lock_init(&img_request->completion_lock);
	img_request->next_completion = 0;
	img_request->callback = NULL;
2179
	img_request->result = 0;
A
Alex Elder 已提交
2180 2181 2182 2183
	img_request->obj_request_count = 0;
	INIT_LIST_HEAD(&img_request->obj_requests);
	kref_init(&img_request->kref);

A
Alex Elder 已提交
2184
	dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
G
Guangliang Zhao 已提交
2185
		obj_op_name(op_type), offset, length, img_request);
A
Alex Elder 已提交
2186

A
Alex Elder 已提交
2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197
	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
2198 2199
	dout("%s: img %p\n", __func__, img_request);

A
Alex Elder 已提交
2200 2201
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
		rbd_img_obj_request_del(img_request, obj_request);
2202
	rbd_assert(img_request->obj_request_count == 0);
A
Alex Elder 已提交
2203

2204 2205 2206 2207 2208
	if (img_request_layered_test(img_request)) {
		img_request_layered_clear(img_request);
		rbd_dev_parent_put(img_request->rbd_dev);
	}

2209 2210
	if (img_request_write_test(img_request) ||
		img_request_discard_test(img_request))
2211
		ceph_put_snap_context(img_request->snapc);
A
Alex Elder 已提交
2212

2213
	kmem_cache_free(rbd_img_request_cache, img_request);
A
Alex Elder 已提交
2214 2215
}

2216 2217 2218 2219 2220 2221 2222 2223 2224 2225
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;

2226
	parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
G
Guangliang Zhao 已提交
2227
						length, OBJ_OP_READ, NULL);
2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252
	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);
}

2253 2254
static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
{
2255
	struct rbd_img_request *img_request;
2256 2257
	unsigned int xferred;
	int result;
A
Alex Elder 已提交
2258
	bool more;
2259

2260 2261 2262
	rbd_assert(obj_request_img_data_test(obj_request));
	img_request = obj_request->img_request;

2263 2264 2265 2266 2267
	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
2268 2269
		enum obj_operation_type op_type;

2270 2271 2272 2273 2274 2275
		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;
2276

2277
		rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
G
Guangliang Zhao 已提交
2278 2279
			obj_op_name(op_type), obj_request->length,
			obj_request->img_offset, obj_request->offset);
2280
		rbd_warn(rbd_dev, "  result %d xferred %x",
2281 2282 2283
			result, xferred);
		if (!img_request->result)
			img_request->result = result;
2284 2285 2286 2287 2288
		/*
		 * Need to end I/O on the entire obj_request worth of
		 * bytes in case of error.
		 */
		xferred = obj_request->length;
2289 2290
	}

2291 2292 2293 2294 2295 2296 2297
	/* Image object requests don't own their page array */

	if (obj_request->type == OBJ_REQUEST_PAGES) {
		obj_request->pages = NULL;
		obj_request->page_count = 0;
	}

A
Alex Elder 已提交
2298 2299 2300 2301 2302
	if (img_request_child_test(img_request)) {
		rbd_assert(img_request->obj_request != NULL);
		more = obj_request->which < img_request->obj_request_count - 1;
	} else {
		rbd_assert(img_request->rq != NULL);
C
Christoph Hellwig 已提交
2303 2304 2305 2306

		more = blk_update_request(img_request->rq, result, xferred);
		if (!more)
			__blk_mq_end_request(img_request->rq, result);
A
Alex Elder 已提交
2307 2308 2309
	}

	return more;
2310 2311
}

2312 2313 2314 2315 2316 2317
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;

2318
	rbd_assert(obj_request_img_data_test(obj_request));
2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336
	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;
2337
		more = rbd_img_obj_end_request(obj_request);
2338 2339 2340 2341 2342 2343 2344
		which++;
	}

	rbd_assert(more ^ (which == img_request->obj_request_count));
	img_request->next_completion = which;
out:
	spin_unlock_irq(&img_request->completion_lock);
2345
	rbd_img_request_put(img_request);
2346 2347 2348 2349 2350

	if (!more)
		rbd_img_request_complete(img_request);
}

2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369
/*
 * 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) {
2370 2371 2372
		if (!offset && length == object_size &&
		    (!img_request_layered_test(img_request) ||
		     !obj_request_overlaps_parent(obj_request))) {
2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394
			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) {
		opcode = CEPH_OSD_OP_WRITE;
		osd_req_op_alloc_hint_init(osd_request, num_ops,
					object_size, object_size);
		num_ops++;
	} else {
		opcode = CEPH_OSD_OP_READ;
	}

2395
	if (opcode == CEPH_OSD_OP_DELETE)
2396
		osd_req_op_init(osd_request, num_ops, opcode, 0);
2397 2398 2399 2400
	else
		osd_req_op_extent_init(osd_request, num_ops, opcode,
				       offset, length, 0, 0);

2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415
	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);
}

2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426
/*
 * 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
2427 2428 2429 2430
{
	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
2431
	struct bio *bio_list = NULL;
2432
	unsigned int bio_offset = 0;
J
Jingoo Han 已提交
2433
	struct page **pages = NULL;
G
Guangliang Zhao 已提交
2434
	enum obj_operation_type op_type;
2435
	u64 img_offset;
A
Alex Elder 已提交
2436 2437
	u64 resid;

2438 2439
	dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
		(int)type, data_desc);
A
Alex Elder 已提交
2440

2441
	img_offset = img_request->offset;
A
Alex Elder 已提交
2442
	resid = img_request->length;
A
Alex Elder 已提交
2443
	rbd_assert(resid > 0);
2444
	op_type = rbd_img_request_op_type(img_request);
2445 2446 2447

	if (type == OBJ_REQUEST_BIO) {
		bio_list = data_desc;
2448 2449
		rbd_assert(img_offset ==
			   bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2450
	} else if (type == OBJ_REQUEST_PAGES) {
2451 2452 2453
		pages = data_desc;
	}

A
Alex Elder 已提交
2454
	while (resid) {
2455
		struct ceph_osd_request *osd_req;
A
Alex Elder 已提交
2456 2457 2458 2459
		const char *object_name;
		u64 offset;
		u64 length;

2460
		object_name = rbd_segment_name(rbd_dev, img_offset);
A
Alex Elder 已提交
2461 2462
		if (!object_name)
			goto out_unwind;
2463 2464
		offset = rbd_segment_offset(rbd_dev, img_offset);
		length = rbd_segment_length(rbd_dev, img_offset, resid);
A
Alex Elder 已提交
2465
		obj_request = rbd_obj_request_create(object_name,
2466
						offset, length, type);
2467 2468
		/* object request has its own copy of the object name */
		rbd_segment_name_free(object_name);
A
Alex Elder 已提交
2469 2470
		if (!obj_request)
			goto out_unwind;
2471

2472 2473 2474 2475 2476
		/*
		 * 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
2477

2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488
		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,
								GFP_ATOMIC);
			if (!obj_request->bio_list)
2489
				goto out_unwind;
2490
		} else if (type == OBJ_REQUEST_PAGES) {
2491 2492 2493 2494 2495 2496 2497 2498 2499
			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
2500

G
Guangliang Zhao 已提交
2501 2502 2503
		osd_req = rbd_osd_req_create(rbd_dev, op_type,
					(op_type == OBJ_OP_WRITE) ? 2 : 1,
					obj_request);
2504
		if (!osd_req)
2505
			goto out_unwind;
2506

2507
		obj_request->osd_req = osd_req;
2508
		obj_request->callback = rbd_img_obj_callback;
2509
		obj_request->img_offset = img_offset;
2510

2511
		rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
A
Alex Elder 已提交
2512

2513
		rbd_img_request_get(img_request);
A
Alex Elder 已提交
2514

2515
		img_offset += length;
A
Alex Elder 已提交
2516 2517 2518 2519 2520 2521 2522
		resid -= length;
	}

	return 0;

out_unwind:
	for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2523
		rbd_img_obj_request_del(img_request, obj_request);
A
Alex Elder 已提交
2524 2525 2526 2527

	return -ENOMEM;
}

2528 2529 2530 2531 2532
static void
rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request;
	struct rbd_device *rbd_dev;
2533
	struct page **pages;
2534 2535
	u32 page_count;

2536 2537
	rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
		obj_request->type == OBJ_REQUEST_NODATA);
2538 2539 2540 2541 2542 2543 2544
	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);

2545 2546
	pages = obj_request->copyup_pages;
	rbd_assert(pages != NULL);
2547
	obj_request->copyup_pages = NULL;
2548 2549 2550 2551
	page_count = obj_request->copyup_page_count;
	rbd_assert(page_count);
	obj_request->copyup_page_count = 0;
	ceph_release_page_vector(pages, page_count);
2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566

	/*
	 * 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;

	/* Finish up with the normal image object callback */

	rbd_img_obj_callback(obj_request);
}

2567 2568 2569 2570
static void
rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *orig_request;
2571 2572 2573
	struct ceph_osd_request *osd_req;
	struct ceph_osd_client *osdc;
	struct rbd_device *rbd_dev;
2574
	struct page **pages;
2575
	enum obj_operation_type op_type;
2576
	u32 page_count;
2577
	int img_result;
2578
	u64 parent_length;
2579 2580 2581 2582 2583 2584 2585 2586

	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;
2587 2588 2589
	page_count = img_request->copyup_page_count;
	rbd_assert(page_count);
	img_request->copyup_page_count = 0;
2590 2591 2592

	orig_request = img_request->obj_request;
	rbd_assert(orig_request != NULL);
2593
	rbd_assert(obj_request_type_valid(orig_request->type));
2594
	img_result = img_request->result;
2595 2596
	parent_length = img_request->length;
	rbd_assert(parent_length == img_request->xferred);
2597
	rbd_img_request_put(img_request);
2598

2599 2600
	rbd_assert(orig_request->img_request);
	rbd_dev = orig_request->img_request->rbd_dev;
2601 2602
	rbd_assert(rbd_dev);

2603 2604 2605 2606 2607 2608 2609
	/*
	 * 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) {
		struct ceph_osd_client *osdc;
2610

2611 2612 2613 2614 2615 2616
		ceph_release_page_vector(pages, page_count);
		osdc = &rbd_dev->rbd_client->client->osdc;
		img_result = rbd_obj_request_submit(osdc, orig_request);
		if (!img_result)
			return;
	}
2617

2618
	if (img_result)
2619 2620
		goto out_err;

2621 2622
	/*
	 * The original osd request is of no use to use any more.
2623
	 * We need a new one that can hold the three ops in a copyup
2624 2625 2626
	 * request.  Allocate the new copyup osd request for the
	 * original request, and release the old one.
	 */
2627
	img_result = -ENOMEM;
2628 2629 2630
	osd_req = rbd_osd_req_create_copyup(orig_request);
	if (!osd_req)
		goto out_err;
2631
	rbd_osd_req_destroy(orig_request->osd_req);
2632 2633
	orig_request->osd_req = osd_req;
	orig_request->copyup_pages = pages;
2634
	orig_request->copyup_page_count = page_count;
2635

2636
	/* Initialize the copyup op */
2637

2638
	osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2639
	osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2640
						false, false);
2641

2642
	/* Add the other op(s) */
2643

2644 2645
	op_type = rbd_img_request_op_type(orig_request->img_request);
	rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2646 2647 2648 2649 2650

	/* All set, send it off. */

	orig_request->callback = rbd_img_obj_copyup_callback;
	osdc = &rbd_dev->rbd_client->client->osdc;
2651 2652
	img_result = rbd_obj_request_submit(osdc, orig_request);
	if (!img_result)
2653 2654 2655 2656
		return;
out_err:
	/* Record the error code and complete the request */

2657
	orig_request->result = img_result;
2658 2659 2660
	orig_request->xferred = 0;
	obj_request_done_set(orig_request);
	rbd_obj_request_complete(orig_request);
2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688
}

/*
 * 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.
 *
 * If an error occurs, record it as the result of the original
 * object request and mark it done so it gets completed.
 */
static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
{
	struct rbd_img_request *img_request = NULL;
	struct rbd_img_request *parent_request = NULL;
	struct rbd_device *rbd_dev;
	u64 img_offset;
	u64 length;
	struct page **pages = NULL;
	u32 page_count;
	int result;

	rbd_assert(obj_request_img_data_test(obj_request));
2689
	rbd_assert(obj_request_type_valid(obj_request->type));
2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702

	img_request = obj_request->img_request;
	rbd_assert(img_request != NULL);
	rbd_dev = img_request->rbd_dev;
	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;
	length = (u64)1 << rbd_dev->header.obj_order;

A
Alex Elder 已提交
2703 2704 2705 2706 2707 2708 2709 2710 2711 2712
	/*
	 * 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;
	}

2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725
	/*
	 * Allocate a page array big enough to receive the data read
	 * from the parent.
	 */
	page_count = (u32)calc_pages_for(0, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages)) {
		result = PTR_ERR(pages);
		pages = NULL;
		goto out_err;
	}

	result = -ENOMEM;
2726 2727
	parent_request = rbd_parent_request_create(obj_request,
						img_offset, length);
2728 2729 2730 2731 2732 2733 2734
	if (!parent_request)
		goto out_err;

	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
	if (result)
		goto out_err;
	parent_request->copyup_pages = pages;
2735
	parent_request->copyup_page_count = page_count;
2736 2737 2738 2739 2740 2741 2742

	parent_request->callback = rbd_img_obj_parent_read_full_callback;
	result = rbd_img_request_submit(parent_request);
	if (!result)
		return 0;

	parent_request->copyup_pages = NULL;
2743
	parent_request->copyup_page_count = 0;
2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757
	parent_request->obj_request = NULL;
	rbd_obj_request_put(obj_request);
out_err:
	if (pages)
		ceph_release_page_vector(pages, page_count);
	if (parent_request)
		rbd_img_request_put(parent_request);
	obj_request->result = result;
	obj_request->xferred = 0;
	obj_request_done_set(obj_request);

	return result;
}

2758 2759 2760
static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *orig_request;
2761
	struct rbd_device *rbd_dev;
2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
	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;
2773
	rbd_obj_request_put(orig_request);
2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784
	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);

2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798
	/*
	 * 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.
	 */
	rbd_dev = orig_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
		struct ceph_osd_client *osdc;

		osdc = &rbd_dev->rbd_client->client->osdc;
		result = rbd_obj_request_submit(osdc, orig_request);
		if (!result)
			return;
	}
2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811

	/*
	 * 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);
	} else if (result) {
		orig_request->result = result;
2812
		goto out;
2813 2814 2815 2816 2817 2818
	}

	/*
	 * Resubmit the original request now that we have recorded
	 * whether the target object exists.
	 */
2819
	orig_request->result = rbd_img_obj_request_submit(orig_request);
2820
out:
2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861
	if (orig_request->result)
		rbd_obj_request_complete(orig_request);
}

static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
{
	struct rbd_obj_request *stat_request;
	struct rbd_device *rbd_dev;
	struct ceph_osd_client *osdc;
	struct page **pages = NULL;
	u32 page_count;
	size_t size;
	int ret;

	/*
	 * The response data for a STAT call consists of:
	 *     le64 length;
	 *     struct {
	 *         le32 tv_sec;
	 *         le32 tv_nsec;
	 *     } mtime;
	 */
	size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
	page_count = (u32)calc_pages_for(0, size);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	ret = -ENOMEM;
	stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
							OBJ_REQUEST_PAGES);
	if (!stat_request)
		goto out;

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

	rbd_assert(obj_request->img_request);
	rbd_dev = obj_request->img_request->rbd_dev;
G
Guangliang Zhao 已提交
2862
	stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
2863
						   stat_request);
2864 2865 2866 2867
	if (!stat_request->osd_req)
		goto out;
	stat_request->callback = rbd_img_obj_exists_callback;

2868
	osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
2869 2870
	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
					false, false);
2871
	rbd_osd_req_format_read(stat_request);
2872 2873 2874 2875 2876 2877 2878 2879 2880 2881

	osdc = &rbd_dev->rbd_client->client->osdc;
	ret = rbd_obj_request_submit(osdc, stat_request);
out:
	if (ret)
		rbd_obj_request_put(obj_request);

	return ret;
}

2882
static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2883 2884
{
	struct rbd_img_request *img_request;
A
Alex Elder 已提交
2885
	struct rbd_device *rbd_dev;
2886 2887 2888 2889 2890

	rbd_assert(obj_request_img_data_test(obj_request));

	img_request = obj_request->img_request;
	rbd_assert(img_request);
A
Alex Elder 已提交
2891
	rbd_dev = img_request->rbd_dev;
2892

2893
	/* Reads */
2894 2895
	if (!img_request_write_test(img_request) &&
	    !img_request_discard_test(img_request))
2896 2897 2898 2899 2900 2901
		return true;

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

2902
	/*
2903 2904
	 * Layered writes outside of the parent overlap range don't
	 * share any data with the parent.
2905
	 */
2906 2907
	if (!obj_request_overlaps_parent(obj_request))
		return true;
2908

2909 2910 2911 2912 2913 2914 2915 2916
	/*
	 * 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;

2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930
	/*
	 * 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)
{
	if (img_obj_request_simple(obj_request)) {
2931 2932 2933 2934 2935 2936 2937 2938 2939 2940
		struct rbd_device *rbd_dev;
		struct ceph_osd_client *osdc;

		rbd_dev = obj_request->img_request->rbd_dev;
		osdc = &rbd_dev->rbd_client->client->osdc;

		return rbd_obj_request_submit(osdc, obj_request);
	}

	/*
2941 2942 2943 2944
	 * 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.
2945
	 */
2946
	if (obj_request_known_test(obj_request))
2947 2948 2949
		return rbd_img_obj_parent_read_full(obj_request);

	/* We don't know whether the target exists.  Go find out. */
2950 2951 2952 2953

	return rbd_img_obj_exists_submit(obj_request);
}

A
Alex Elder 已提交
2954 2955 2956
static int rbd_img_request_submit(struct rbd_img_request *img_request)
{
	struct rbd_obj_request *obj_request;
2957
	struct rbd_obj_request *next_obj_request;
A
Alex Elder 已提交
2958

A
Alex Elder 已提交
2959
	dout("%s: img %p\n", __func__, img_request);
2960
	for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
A
Alex Elder 已提交
2961 2962
		int ret;

2963
		ret = rbd_img_obj_request_submit(obj_request);
A
Alex Elder 已提交
2964 2965 2966 2967 2968 2969
		if (ret)
			return ret;
	}

	return 0;
}
A
Alex Elder 已提交
2970 2971 2972 2973

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
2974 2975
	struct rbd_device *rbd_dev;
	u64 obj_end;
2976 2977
	u64 img_xferred;
	int img_result;
A
Alex Elder 已提交
2978 2979 2980

	rbd_assert(img_request_child_test(img_request));

2981 2982
	/* First get what we need from the image request and release it */

A
Alex Elder 已提交
2983
	obj_request = img_request->obj_request;
2984 2985 2986 2987 2988 2989 2990 2991 2992
	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
2993 2994
	rbd_assert(obj_request);
	rbd_assert(obj_request->img_request);
2995 2996 2997 2998 2999 3000 3001 3002 3003
	rbd_dev = obj_request->img_request->rbd_dev;
	if (!rbd_dev->parent_overlap) {
		struct ceph_osd_client *osdc;

		osdc = &rbd_dev->rbd_client->client->osdc;
		img_result = rbd_obj_request_submit(osdc, obj_request);
		if (!img_result)
			return;
	}
A
Alex Elder 已提交
3004

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

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

		if (obj_request->img_offset < rbd_dev->parent_overlap)
			xferred = rbd_dev->parent_overlap -
					obj_request->img_offset;
A
Alex Elder 已提交
3024

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

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

	rbd_assert(obj_request_img_data_test(obj_request));
	rbd_assert(obj_request->img_request != NULL);
	rbd_assert(obj_request->result == (s32) -ENOENT);
3042
	rbd_assert(obj_request_type_valid(obj_request->type));
A
Alex Elder 已提交
3043 3044

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

3052 3053 3054 3055 3056 3057
	if (obj_request->type == OBJ_REQUEST_BIO)
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
						obj_request->bio_list);
	else
		result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
						obj_request->pages);
A
Alex Elder 已提交
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073
	if (result)
		goto out_err;

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

	return;
out_err:
	if (img_request)
		rbd_img_request_put(img_request);
	obj_request->result = result;
	obj_request->xferred = 0;
	obj_request_done_set(obj_request);
}
A
Alex Elder 已提交
3074

3075
static int rbd_obj_notify_ack_sync(struct rbd_device *rbd_dev, u64 notify_id)
A
Alex Elder 已提交
3076 3077
{
	struct rbd_obj_request *obj_request;
3078
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
A
Alex Elder 已提交
3079 3080 3081 3082 3083 3084 3085 3086
	int ret;

	obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
							OBJ_REQUEST_NODATA);
	if (!obj_request)
		return -ENOMEM;

	ret = -ENOMEM;
G
Guangliang Zhao 已提交
3087
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
3088
						  obj_request);
A
Alex Elder 已提交
3089 3090 3091
	if (!obj_request->osd_req)
		goto out;

3092
	osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
A
Alex Elder 已提交
3093
					notify_id, 0, 0);
3094
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
3095

A
Alex Elder 已提交
3096
	ret = rbd_obj_request_submit(osdc, obj_request);
A
Alex Elder 已提交
3097
	if (ret)
3098 3099 3100 3101
		goto out;
	ret = rbd_obj_request_wait(obj_request);
out:
	rbd_obj_request_put(obj_request);
A
Alex Elder 已提交
3102 3103 3104 3105 3106 3107 3108

	return ret;
}

static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
{
	struct rbd_device *rbd_dev = (struct rbd_device *)data;
3109
	int ret;
A
Alex Elder 已提交
3110 3111 3112 3113

	if (!rbd_dev)
		return;

A
Alex Elder 已提交
3114
	dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
A
Alex Elder 已提交
3115 3116
		rbd_dev->header_name, (unsigned long long)notify_id,
		(unsigned int)opcode);
3117 3118 3119 3120 3121 3122 3123

	/*
	 * Until adequate refresh error handling is in place, there is
	 * not much we can do here, except warn.
	 *
	 * See http://tracker.ceph.com/issues/5040
	 */
3124 3125
	ret = rbd_dev_refresh(rbd_dev);
	if (ret)
3126
		rbd_warn(rbd_dev, "refresh failed: %d", ret);
A
Alex Elder 已提交
3127

3128 3129
	ret = rbd_obj_notify_ack_sync(rbd_dev, notify_id);
	if (ret)
3130
		rbd_warn(rbd_dev, "notify_ack ret %d", ret);
A
Alex Elder 已提交
3131 3132
}

3133 3134 3135 3136 3137 3138 3139 3140 3141
/*
 * Send a (un)watch request and wait for the ack.  Return a request
 * with a ref held on success or error.
 */
static struct rbd_obj_request *rbd_obj_watch_request_helper(
						struct rbd_device *rbd_dev,
						bool watch)
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3142
	struct ceph_options *opts = osdc->client->options;
3143 3144 3145 3146 3147 3148 3149 3150
	struct rbd_obj_request *obj_request;
	int ret;

	obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
					     OBJ_REQUEST_NODATA);
	if (!obj_request)
		return ERR_PTR(-ENOMEM);

G
Guangliang Zhao 已提交
3151
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_WRITE, 1,
3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168
						  obj_request);
	if (!obj_request->osd_req) {
		ret = -ENOMEM;
		goto out;
	}

	osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
			      rbd_dev->watch_event->cookie, 0, watch);
	rbd_osd_req_format_write(obj_request);

	if (watch)
		ceph_osdc_set_request_linger(osdc, obj_request->osd_req);

	ret = rbd_obj_request_submit(osdc, obj_request);
	if (ret)
		goto out;

3169
	ret = rbd_obj_request_wait_timeout(obj_request, opts->mount_timeout);
3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret) {
		if (watch)
			rbd_obj_request_end(obj_request);
		goto out;
	}

	return obj_request;

out:
	rbd_obj_request_put(obj_request);
	return ERR_PTR(ret);
}

3187
/*
3188
 * Initiate a watch request, synchronously.
3189
 */
3190
static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev)
3191 3192 3193 3194 3195
{
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
	struct rbd_obj_request *obj_request;
	int ret;

3196 3197
	rbd_assert(!rbd_dev->watch_event);
	rbd_assert(!rbd_dev->watch_request);
3198

3199 3200 3201 3202 3203
	ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
				     &rbd_dev->watch_event);
	if (ret < 0)
		return ret;

3204 3205 3206 3207 3208
	obj_request = rbd_obj_watch_request_helper(rbd_dev, true);
	if (IS_ERR(obj_request)) {
		ceph_osdc_cancel_event(rbd_dev->watch_event);
		rbd_dev->watch_event = NULL;
		return PTR_ERR(obj_request);
3209
	}
3210

3211 3212 3213 3214
	/*
	 * A watch request is set to linger, so the underlying osd
	 * request won't go away until we unregister it.  We retain
	 * a pointer to the object request during that time (in
3215 3216 3217
	 * rbd_dev->watch_request), so we'll keep a reference to it.
	 * We'll drop that reference after we've unregistered it in
	 * rbd_dev_header_unwatch_sync().
3218
	 */
3219
	rbd_dev->watch_request = obj_request;
3220

3221 3222 3223 3224 3225 3226
	return 0;
}

/*
 * Tear down a watch request, synchronously.
 */
3227
static void rbd_dev_header_unwatch_sync(struct rbd_device *rbd_dev)
3228 3229 3230 3231 3232 3233
{
	struct rbd_obj_request *obj_request;

	rbd_assert(rbd_dev->watch_event);
	rbd_assert(rbd_dev->watch_request);

3234
	rbd_obj_request_end(rbd_dev->watch_request);
3235 3236
	rbd_obj_request_put(rbd_dev->watch_request);
	rbd_dev->watch_request = NULL;
3237

3238 3239 3240 3241 3242 3243 3244
	obj_request = rbd_obj_watch_request_helper(rbd_dev, false);
	if (!IS_ERR(obj_request))
		rbd_obj_request_put(obj_request);
	else
		rbd_warn(rbd_dev, "unable to tear down watch request (%ld)",
			 PTR_ERR(obj_request));

3245 3246
	ceph_osdc_cancel_event(rbd_dev->watch_event);
	rbd_dev->watch_event = NULL;
3247 3248
}

3249
/*
3250 3251
 * Synchronous osd object method call.  Returns the number of bytes
 * returned in the outbound buffer, or a negative error code.
3252 3253 3254 3255 3256
 */
static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
			     const char *object_name,
			     const char *class_name,
			     const char *method_name,
3257
			     const void *outbound,
3258
			     size_t outbound_size,
3259
			     void *inbound,
3260
			     size_t inbound_size)
3261
{
3262
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3263 3264 3265 3266 3267 3268
	struct rbd_obj_request *obj_request;
	struct page **pages;
	u32 page_count;
	int ret;

	/*
3269 3270 3271 3272 3273
	 * 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.
3274
	 */
3275
	page_count = (u32)calc_pages_for(0, inbound_size);
3276 3277 3278 3279 3280
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	ret = -ENOMEM;
3281
	obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
3282 3283 3284 3285 3286 3287 3288
							OBJ_REQUEST_PAGES);
	if (!obj_request)
		goto out;

	obj_request->pages = pages;
	obj_request->page_count = page_count;

G
Guangliang Zhao 已提交
3289
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
3290
						  obj_request);
3291 3292 3293
	if (!obj_request->osd_req)
		goto out;

3294
	osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307
					class_name, method_name);
	if (outbound_size) {
		struct ceph_pagelist *pagelist;

		pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
		if (!pagelist)
			goto out;

		ceph_pagelist_init(pagelist);
		ceph_pagelist_append(pagelist, outbound, outbound_size);
		osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
						pagelist);
	}
3308 3309
	osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
					obj_request->pages, inbound_size,
3310
					0, false, false);
3311
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
3312

3313 3314 3315 3316 3317 3318 3319 3320 3321 3322
	ret = rbd_obj_request_submit(osdc, obj_request);
	if (ret)
		goto out;
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
3323 3324 3325

	rbd_assert(obj_request->xferred < (u64)INT_MAX);
	ret = (int)obj_request->xferred;
3326
	ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
3327 3328 3329 3330 3331 3332 3333 3334 3335
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

C
Christoph Hellwig 已提交
3336
static void rbd_queue_workfn(struct work_struct *work)
A
Alex Elder 已提交
3337
{
C
Christoph Hellwig 已提交
3338 3339
	struct request *rq = blk_mq_rq_from_pdu(work);
	struct rbd_device *rbd_dev = rq->q->queuedata;
I
Ilya Dryomov 已提交
3340
	struct rbd_img_request *img_request;
3341
	struct ceph_snap_context *snapc = NULL;
I
Ilya Dryomov 已提交
3342 3343
	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
	u64 length = blk_rq_bytes(rq);
G
Guangliang Zhao 已提交
3344
	enum obj_operation_type op_type;
3345
	u64 mapping_size;
A
Alex Elder 已提交
3346 3347
	int result;

C
Christoph Hellwig 已提交
3348 3349 3350 3351 3352 3353 3354
	if (rq->cmd_type != REQ_TYPE_FS) {
		dout("%s: non-fs request type %d\n", __func__,
			(int) rq->cmd_type);
		result = -EIO;
		goto err;
	}

3355 3356 3357
	if (rq->cmd_flags & REQ_DISCARD)
		op_type = OBJ_OP_DISCARD;
	else if (rq->cmd_flags & REQ_WRITE)
G
Guangliang Zhao 已提交
3358 3359 3360 3361
		op_type = OBJ_OP_WRITE;
	else
		op_type = OBJ_OP_READ;

I
Ilya Dryomov 已提交
3362
	/* Ignore/skip any zero-length requests */
A
Alex Elder 已提交
3363

I
Ilya Dryomov 已提交
3364 3365 3366 3367 3368
	if (!length) {
		dout("%s: zero-length request\n", __func__);
		result = 0;
		goto err_rq;
	}
A
Alex Elder 已提交
3369

G
Guangliang Zhao 已提交
3370
	/* Only reads are allowed to a read-only device */
I
Ilya Dryomov 已提交
3371

G
Guangliang Zhao 已提交
3372
	if (op_type != OBJ_OP_READ) {
I
Ilya Dryomov 已提交
3373 3374 3375
		if (rbd_dev->mapping.read_only) {
			result = -EROFS;
			goto err_rq;
A
Alex Elder 已提交
3376
		}
I
Ilya Dryomov 已提交
3377 3378
		rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
	}
A
Alex Elder 已提交
3379

I
Ilya Dryomov 已提交
3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391
	/*
	 * 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
3392

I
Ilya Dryomov 已提交
3393 3394 3395 3396 3397 3398
	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
3399

C
Christoph Hellwig 已提交
3400 3401
	blk_mq_start_request(rq);

3402 3403
	down_read(&rbd_dev->header_rwsem);
	mapping_size = rbd_dev->mapping.size;
G
Guangliang Zhao 已提交
3404
	if (op_type != OBJ_OP_READ) {
3405 3406 3407 3408 3409 3410
		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
3411
		rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
3412
			 length, mapping_size);
I
Ilya Dryomov 已提交
3413 3414 3415
		result = -EIO;
		goto err_rq;
	}
A
Alex Elder 已提交
3416

G
Guangliang Zhao 已提交
3417
	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
3418
					     snapc);
I
Ilya Dryomov 已提交
3419 3420 3421 3422 3423
	if (!img_request) {
		result = -ENOMEM;
		goto err_rq;
	}
	img_request->rq = rq;
A
Alex Elder 已提交
3424

3425 3426 3427 3428 3429 3430
	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
3431 3432
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3433

I
Ilya Dryomov 已提交
3434 3435 3436
	result = rbd_img_request_submit(img_request);
	if (result)
		goto err_img_request;
A
Alex Elder 已提交
3437

I
Ilya Dryomov 已提交
3438
	return;
A
Alex Elder 已提交
3439

I
Ilya Dryomov 已提交
3440 3441 3442 3443 3444
err_img_request:
	rbd_img_request_put(img_request);
err_rq:
	if (result)
		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
G
Guangliang Zhao 已提交
3445
			 obj_op_name(op_type), length, offset, result);
3446
	ceph_put_snap_context(snapc);
C
Christoph Hellwig 已提交
3447 3448
err:
	blk_mq_end_request(rq, result);
I
Ilya Dryomov 已提交
3449
}
A
Alex Elder 已提交
3450

C
Christoph Hellwig 已提交
3451 3452
static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
		const struct blk_mq_queue_data *bd)
I
Ilya Dryomov 已提交
3453
{
C
Christoph Hellwig 已提交
3454 3455
	struct request *rq = bd->rq;
	struct work_struct *work = blk_mq_rq_to_pdu(rq);
A
Alex Elder 已提交
3456

C
Christoph Hellwig 已提交
3457 3458
	queue_work(rbd_wq, work);
	return BLK_MQ_RQ_QUEUE_OK;
A
Alex Elder 已提交
3459 3460
}

3461 3462 3463
/*
 * a queue callback. Makes sure that we don't create a bio that spans across
 * multiple osd objects. One exception would be with a single page bios,
A
Alex Elder 已提交
3464
 * which we handle later at bio_chain_clone_range()
3465 3466 3467 3468 3469
 */
static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
			  struct bio_vec *bvec)
{
	struct rbd_device *rbd_dev = q->queuedata;
A
Alex Elder 已提交
3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504
	sector_t sector_offset;
	sector_t sectors_per_obj;
	sector_t obj_sector_offset;
	int ret;

	/*
	 * Find how far into its rbd object the partition-relative
	 * bio start sector is to offset relative to the enclosing
	 * device.
	 */
	sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
	sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
	obj_sector_offset = sector_offset & (sectors_per_obj - 1);

	/*
	 * Compute the number of bytes from that offset to the end
	 * of the object.  Account for what's already used by the bio.
	 */
	ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
	if (ret > bmd->bi_size)
		ret -= bmd->bi_size;
	else
		ret = 0;

	/*
	 * Don't send back more than was asked for.  And if the bio
	 * was empty, let the whole thing through because:  "Note
	 * that a block device *must* allow a single page to be
	 * added to an empty bio."
	 */
	rbd_assert(bvec->bv_len <= PAGE_SIZE);
	if (ret > (int) bvec->bv_len || !bmd->bi_size)
		ret = (int) bvec->bv_len;

	return ret;
3505 3506 3507 3508 3509 3510 3511 3512 3513
}

static void rbd_free_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk = rbd_dev->disk;

	if (!disk)
		return;

3514 3515
	rbd_dev->disk = NULL;
	if (disk->flags & GENHD_FL_UP) {
3516
		del_gendisk(disk);
3517 3518
		if (disk->queue)
			blk_cleanup_queue(disk->queue);
C
Christoph Hellwig 已提交
3519
		blk_mq_free_tag_set(&rbd_dev->tag_set);
3520
	}
3521 3522 3523
	put_disk(disk);
}

3524 3525
static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
				const char *object_name,
3526
				u64 offset, u64 length, void *buf)
3527 3528

{
3529
	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3530 3531 3532
	struct rbd_obj_request *obj_request;
	struct page **pages = NULL;
	u32 page_count;
3533
	size_t size;
3534 3535 3536 3537 3538
	int ret;

	page_count = (u32) calc_pages_for(offset, length);
	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
	if (IS_ERR(pages))
3539
		return PTR_ERR(pages);
3540 3541 3542

	ret = -ENOMEM;
	obj_request = rbd_obj_request_create(object_name, offset, length,
3543
							OBJ_REQUEST_PAGES);
3544 3545 3546 3547 3548 3549
	if (!obj_request)
		goto out;

	obj_request->pages = pages;
	obj_request->page_count = page_count;

G
Guangliang Zhao 已提交
3550
	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
3551
						  obj_request);
3552 3553 3554
	if (!obj_request->osd_req)
		goto out;

3555 3556
	osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
					offset, length, 0, 0);
3557
	osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
3558
					obj_request->pages,
3559 3560 3561
					obj_request->length,
					obj_request->offset & ~PAGE_MASK,
					false, false);
3562
	rbd_osd_req_format_read(obj_request);
A
Alex Elder 已提交
3563

3564 3565 3566 3567 3568 3569 3570 3571 3572 3573
	ret = rbd_obj_request_submit(osdc, obj_request);
	if (ret)
		goto out;
	ret = rbd_obj_request_wait(obj_request);
	if (ret)
		goto out;

	ret = obj_request->result;
	if (ret < 0)
		goto out;
3574 3575 3576

	rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
	size = (size_t) obj_request->xferred;
3577
	ceph_copy_from_page_vector(pages, buf, 0, size);
3578 3579
	rbd_assert(size <= (size_t)INT_MAX);
	ret = (int)size;
3580 3581 3582 3583 3584 3585 3586 3587 3588
out:
	if (obj_request)
		rbd_obj_request_put(obj_request);
	else
		ceph_release_page_vector(pages, page_count);

	return ret;
}

3589
/*
A
Alex Elder 已提交
3590 3591 3592
 * 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.
3593
 */
3594
static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3595
{
3596
	struct rbd_image_header_ondisk *ondisk = NULL;
3597
	u32 snap_count = 0;
3598 3599 3600
	u64 names_size = 0;
	u32 want_count;
	int ret;
3601

A
Alex Elder 已提交
3602
	/*
3603 3604 3605 3606 3607
	 * 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
3608
	 */
3609 3610 3611 3612 3613 3614 3615 3616 3617 3618
	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
3619
			return -ENOMEM;
3620

3621
		ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3622
				       0, size, ondisk);
3623
		if (ret < 0)
A
Alex Elder 已提交
3624
			goto out;
A
Alex Elder 已提交
3625
		if ((size_t)ret < size) {
3626
			ret = -ENXIO;
A
Alex Elder 已提交
3627 3628
			rbd_warn(rbd_dev, "short header read (want %zd got %d)",
				size, ret);
A
Alex Elder 已提交
3629
			goto out;
3630 3631 3632
		}
		if (!rbd_dev_ondisk_valid(ondisk)) {
			ret = -ENXIO;
A
Alex Elder 已提交
3633
			rbd_warn(rbd_dev, "invalid header");
A
Alex Elder 已提交
3634
			goto out;
3635
		}
3636

3637 3638 3639 3640
		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
3641

A
Alex Elder 已提交
3642 3643
	ret = rbd_header_from_disk(rbd_dev, ondisk);
out:
3644 3645 3646
	kfree(ondisk);

	return ret;
3647 3648
}

3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667
/*
 * 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);
}

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
static void rbd_dev_update_size(struct rbd_device *rbd_dev)
{
	sector_t size;
	bool removing;

	/*
	 * Don't hold the lock while doing disk operations,
	 * or lock ordering will conflict with the bdev mutex via:
	 * rbd_add() -> blkdev_get() -> rbd_open()
	 */
	spin_lock_irq(&rbd_dev->lock);
	removing = test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
	spin_unlock_irq(&rbd_dev->lock);
	/*
	 * If the device is being removed, rbd_dev->disk has
	 * been destroyed, so don't try to update its size
	 */
	if (!removing) {
		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
3693
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
3694
{
3695
	u64 mapping_size;
A
Alex Elder 已提交
3696 3697
	int ret;

3698
	down_write(&rbd_dev->header_rwsem);
3699
	mapping_size = rbd_dev->mapping.size;
3700 3701

	ret = rbd_dev_header_info(rbd_dev);
3702
	if (ret)
3703
		goto out;
3704

3705 3706 3707 3708 3709 3710 3711
	/*
	 * 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)
3712
			goto out;
3713 3714
	}

3715
	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
3716
		rbd_dev->mapping.size = rbd_dev->header.image_size;
3717 3718 3719 3720
	} else {
		/* validate mapped snapshot's EXISTS flag */
		rbd_exists_validate(rbd_dev);
	}
3721

3722
out:
3723
	up_write(&rbd_dev->header_rwsem);
3724
	if (!ret && mapping_size != rbd_dev->mapping.size)
3725
		rbd_dev_update_size(rbd_dev);
A
Alex Elder 已提交
3726

3727
	return ret;
A
Alex Elder 已提交
3728 3729
}

C
Christoph Hellwig 已提交
3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745
static int rbd_init_request(void *data, struct request *rq,
		unsigned int hctx_idx, unsigned int request_idx,
		unsigned int numa_node)
{
	struct work_struct *work = blk_mq_rq_to_pdu(rq);

	INIT_WORK(work, rbd_queue_workfn);
	return 0;
}

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

3746 3747 3748 3749
static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
A
Alex Elder 已提交
3750
	u64 segment_size;
C
Christoph Hellwig 已提交
3751
	int err;
3752 3753

	/* create gendisk info */
3754 3755 3756
	disk = alloc_disk(single_major ?
			  (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
			  RBD_MINORS_PER_MAJOR);
3757
	if (!disk)
A
Alex Elder 已提交
3758
		return -ENOMEM;
3759

A
Alex Elder 已提交
3760
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
A
Alex Elder 已提交
3761
		 rbd_dev->dev_id);
3762
	disk->major = rbd_dev->major;
3763
	disk->first_minor = rbd_dev->minor;
3764 3765
	if (single_major)
		disk->flags |= GENHD_FL_EXT_DEVT;
3766 3767 3768
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

C
Christoph Hellwig 已提交
3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779
	memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
	rbd_dev->tag_set.ops = &rbd_mq_ops;
	rbd_dev->tag_set.queue_depth = BLKDEV_MAX_RQ;
	rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
	rbd_dev->tag_set.flags =
		BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
	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)
3780
		goto out_disk;
3781

C
Christoph Hellwig 已提交
3782 3783 3784 3785 3786 3787
	q = blk_mq_init_queue(&rbd_dev->tag_set);
	if (IS_ERR(q)) {
		err = PTR_ERR(q);
		goto out_tag_set;
	}

3788 3789
	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
3790

3791
	/* set io sizes to object size */
A
Alex Elder 已提交
3792 3793
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
I
Ilya Dryomov 已提交
3794
	blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
A
Alex Elder 已提交
3795 3796 3797
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
3798

3799 3800 3801 3802
	/* enable the discard support */
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.discard_granularity = segment_size;
	q->limits.discard_alignment = segment_size;
3803 3804
	q->limits.max_discard_sectors = segment_size / SECTOR_SIZE;
	q->limits.discard_zeroes_data = 1;
3805

3806 3807 3808 3809 3810 3811 3812 3813
	blk_queue_merge_bvec(q, rbd_merge_bvec);
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;

	return 0;
C
Christoph Hellwig 已提交
3814 3815
out_tag_set:
	blk_mq_free_tag_set(&rbd_dev->tag_set);
3816 3817
out_disk:
	put_disk(disk);
C
Christoph Hellwig 已提交
3818
	return err;
3819 3820
}

3821 3822 3823 3824
/*
  sysfs
*/

A
Alex Elder 已提交
3825 3826 3827 3828 3829
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

3830 3831 3832
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3833
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3834

A
Alex Elder 已提交
3835 3836
	return sprintf(buf, "%llu\n",
		(unsigned long long)rbd_dev->mapping.size);
3837 3838
}

A
Alex Elder 已提交
3839 3840 3841 3842 3843 3844 3845 3846 3847 3848
/*
 * 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
3849
			(unsigned long long)rbd_dev->mapping.features);
A
Alex Elder 已提交
3850 3851
}

3852 3853 3854
static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3855
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3856

A
Alex Elder 已提交
3857 3858 3859 3860
	if (rbd_dev->major)
		return sprintf(buf, "%d\n", rbd_dev->major);

	return sprintf(buf, "(none)\n");
3861 3862 3863 3864 3865 3866
}

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
3867

3868
	return sprintf(buf, "%d\n", rbd_dev->minor);
3869 3870 3871 3872
}

static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
3873
{
A
Alex Elder 已提交
3874
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3875

3876 3877
	return sprintf(buf, "client%lld\n",
			ceph_client_id(rbd_dev->rbd_client->client));
3878 3879
}

3880 3881
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
3882
{
A
Alex Elder 已提交
3883
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3884

3885
	return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3886 3887
}

3888 3889 3890 3891 3892
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);

3893
	return sprintf(buf, "%llu\n",
A
Alex Elder 已提交
3894
			(unsigned long long) rbd_dev->spec->pool_id);
3895 3896
}

3897 3898 3899
static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
3900
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3901

A
Alex Elder 已提交
3902 3903 3904 3905
	if (rbd_dev->spec->image_name)
		return sprintf(buf, "%s\n", rbd_dev->spec->image_name);

	return sprintf(buf, "(unknown)\n");
3906 3907
}

A
Alex Elder 已提交
3908 3909 3910 3911 3912
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);

3913
	return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
A
Alex Elder 已提交
3914 3915
}

A
Alex Elder 已提交
3916 3917 3918 3919
/*
 * Shows the name of the currently-mapped snapshot (or
 * RBD_SNAP_HEAD_NAME for the base image).
 */
3920 3921 3922 3923
static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
3924
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3925

3926
	return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3927 3928
}

3929
/*
3930 3931 3932
 * 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)".
3933 3934
 */
static ssize_t rbd_parent_show(struct device *dev,
3935 3936
			       struct device_attribute *attr,
			       char *buf)
3937 3938
{
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3939
	ssize_t count = 0;
3940

3941
	if (!rbd_dev->parent)
3942 3943
		return sprintf(buf, "(no parent image)\n");

3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959
	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;
3960 3961
}

3962 3963 3964 3965 3966
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
3967
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3968
	int ret;
3969

A
Alex Elder 已提交
3970
	ret = rbd_dev_refresh(rbd_dev);
3971
	if (ret)
3972
		return ret;
3973

3974
	return size;
3975
}
3976

3977
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
A
Alex Elder 已提交
3978
static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3979
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3980
static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
3981 3982
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3983
static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3984
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
A
Alex Elder 已提交
3985
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3986 3987
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3988
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3989 3990 3991

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
A
Alex Elder 已提交
3992
	&dev_attr_features.attr,
3993
	&dev_attr_major.attr,
3994
	&dev_attr_minor.attr,
3995 3996
	&dev_attr_client_id.attr,
	&dev_attr_pool.attr,
3997
	&dev_attr_pool_id.attr,
3998
	&dev_attr_name.attr,
A
Alex Elder 已提交
3999
	&dev_attr_image_id.attr,
4000
	&dev_attr_current_snap.attr,
4001
	&dev_attr_parent.attr,
4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024
	&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
};

static void rbd_sysfs_dev_release(struct device *dev)
{
}

static struct device_type rbd_device_type = {
	.name		= "rbd",
	.groups		= rbd_attr_groups,
	.release	= rbd_sysfs_dev_release,
};

4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045
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;
4046 4047 4048

	spec->pool_id = CEPH_NOPOOL;
	spec->snap_id = CEPH_NOSNAP;
4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064
	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);
}

A
Alex Elder 已提交
4065
static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
4066 4067 4068 4069 4070 4071 4072 4073 4074
				struct rbd_spec *spec)
{
	struct rbd_device *rbd_dev;

	rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
	if (!rbd_dev)
		return NULL;

	spin_lock_init(&rbd_dev->lock);
4075
	rbd_dev->flags = 0;
4076
	atomic_set(&rbd_dev->parent_ref, 0);
4077 4078 4079 4080 4081 4082
	INIT_LIST_HEAD(&rbd_dev->node);
	init_rwsem(&rbd_dev->header_rwsem);

	rbd_dev->spec = spec;
	rbd_dev->rbd_client = rbdc;

4083 4084 4085 4086 4087 4088 4089
	/* Initialize the layout used for all rbd requests */

	rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
	rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
	rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
	rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);

4090 4091 4092 4093 4094 4095 4096 4097 4098 4099
	return rbd_dev;
}

static void rbd_dev_destroy(struct rbd_device *rbd_dev)
{
	rbd_put_client(rbd_dev->rbd_client);
	rbd_spec_put(rbd_dev->spec);
	kfree(rbd_dev);
}

4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114
/*
 * 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 };

4115
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4116
				"rbd", "get_size",
4117
				&snapid, sizeof (snapid),
4118
				&size_buf, sizeof (size_buf));
4119
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4120 4121
	if (ret < 0)
		return ret;
4122 4123
	if (ret < sizeof (size_buf))
		return -ERANGE;
4124

J
Josh Durgin 已提交
4125
	if (order) {
4126
		*order = size_buf.order;
J
Josh Durgin 已提交
4127 4128
		dout("  order %u", (unsigned int)*order);
	}
4129 4130
	*snap_size = le64_to_cpu(size_buf.size);

J
Josh Durgin 已提交
4131 4132
	dout("  snap_id 0x%016llx snap_size = %llu\n",
		(unsigned long long)snap_id,
4133
		(unsigned long long)*snap_size);
4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144

	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);
}

4145 4146 4147 4148 4149 4150 4151 4152 4153 4154
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;

4155
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4156
				"rbd", "get_object_prefix", NULL, 0,
4157
				reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
4158
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4159 4160 4161 4162 4163
	if (ret < 0)
		goto out;

	p = reply_buf;
	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4164 4165
						p + ret, NULL, GFP_NOIO);
	ret = 0;
4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178

	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;
}

4179 4180 4181 4182 4183 4184 4185
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;
4186
	} __attribute__ ((packed)) features_buf = { 0 };
A
Alex Elder 已提交
4187
	u64 incompat;
4188 4189
	int ret;

4190
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4191
				"rbd", "get_features",
4192
				&snapid, sizeof (snapid),
4193
				&features_buf, sizeof (features_buf));
4194
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4195 4196
	if (ret < 0)
		return ret;
4197 4198
	if (ret < sizeof (features_buf))
		return -ERANGE;
A
Alex Elder 已提交
4199 4200

	incompat = le64_to_cpu(features_buf.incompat);
A
Alex Elder 已提交
4201
	if (incompat & ~RBD_FEATURES_SUPPORTED)
A
Alex Elder 已提交
4202
		return -ENXIO;
A
Alex Elder 已提交
4203

4204 4205 4206
	*snap_features = le64_to_cpu(features_buf.features);

	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4207 4208 4209
		(unsigned long long)snap_id,
		(unsigned long long)*snap_features,
		(unsigned long long)le64_to_cpu(features_buf.incompat));
4210 4211 4212 4213 4214 4215 4216 4217 4218 4219

	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);
}

4220 4221 4222 4223 4224 4225 4226 4227
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
4228
	u64 pool_id;
4229
	char *image_id;
4230
	u64 snap_id;
4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247
	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;
	}

4248
	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4249
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4250
				"rbd", "get_parent",
4251
				&snapid, sizeof (snapid),
4252
				reply_buf, size);
4253
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4254 4255 4256 4257
	if (ret < 0)
		goto out_err;

	p = reply_buf;
4258 4259
	end = reply_buf + ret;
	ret = -ERANGE;
A
Alex Elder 已提交
4260
	ceph_decode_64_safe(&p, end, pool_id, out_err);
4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277
	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);
		}

4278
		goto out;	/* No parent?  No problem. */
4279
	}
4280

4281 4282 4283
	/* The ceph file layout needs to fit pool id in 32 bits */

	ret = -EIO;
A
Alex Elder 已提交
4284
	if (pool_id > (u64)U32_MAX) {
4285
		rbd_warn(NULL, "parent pool id too large (%llu > %u)",
A
Alex Elder 已提交
4286
			(unsigned long long)pool_id, U32_MAX);
4287
		goto out_err;
A
Alex Elder 已提交
4288
	}
4289

A
Alex Elder 已提交
4290
	image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4291 4292 4293 4294
	if (IS_ERR(image_id)) {
		ret = PTR_ERR(image_id);
		goto out_err;
	}
4295
	ceph_decode_64_safe(&p, end, snap_id, out_err);
4296 4297
	ceph_decode_64_safe(&p, end, overlap, out_err);

4298 4299 4300 4301 4302 4303 4304 4305 4306
	/*
	 * 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
4307 4308
		rbd_dev->parent_spec = parent_spec;
		parent_spec = NULL;	/* rbd_dev now owns this */
4309 4310
	} else {
		kfree(image_id);
4311 4312 4313
	}

	/*
4314 4315
	 * We always update the parent overlap.  If it's zero we issue
	 * a warning, as we will proceed as if there was no parent.
4316 4317 4318
	 */
	if (!overlap) {
		if (parent_spec) {
4319 4320 4321 4322
			/* refresh, careful to warn just once */
			if (rbd_dev->parent_overlap)
				rbd_warn(rbd_dev,
				    "clone now standalone (overlap became 0)");
4323
		} else {
4324 4325
			/* initial probe */
			rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
4326
		}
A
Alex Elder 已提交
4327
	}
4328 4329
	rbd_dev->parent_overlap = overlap;

4330 4331 4332 4333 4334 4335 4336 4337 4338
out:
	ret = 0;
out_err:
	kfree(reply_buf);
	rbd_spec_put(parent_spec);

	return ret;
}

4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353
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;

	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
				"rbd", "get_stripe_unit_count", NULL, 0,
4354
				(char *)&striping_info_buf, size);
4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382
	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;
	obj_size = (u64)1 << rbd_dev->header.obj_order;
	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;
	}
4383 4384
	rbd_dev->header.stripe_unit = stripe_unit;
	rbd_dev->header.stripe_count = stripe_count;
4385 4386 4387 4388

	return 0;
}

4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402
static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
{
	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
4403 4404
	len = strlen(rbd_dev->spec->image_id);
	image_id_size = sizeof (__le32) + len;
4405 4406 4407 4408 4409
	image_id = kmalloc(image_id_size, GFP_KERNEL);
	if (!image_id)
		return NULL;

	p = image_id;
4410
	end = image_id + image_id_size;
4411
	ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
4412 4413 4414 4415 4416 4417

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

4418
	ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
4419 4420
				"rbd", "dir_get_name",
				image_id, image_id_size,
4421
				reply_buf, size);
4422 4423 4424
	if (ret < 0)
		goto out;
	p = reply_buf;
4425 4426
	end = reply_buf + ret;

4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438
	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;
}

4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468
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);
4469 4470 4471 4472 4473 4474 4475
		if (IS_ERR(snap_name)) {
			/* ignore no-longer existing snapshots */
			if (PTR_ERR(snap_name) == -ENOENT)
				continue;
			else
				break;
		}
4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493
		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);
}

4494
/*
4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521
 * 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.
4522
 *
4523 4524
 * All names in an rbd spec are dynamically allocated.  It's OK if we
 * can't figure out the name for an image id.
4525
 */
4526
static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
4527
{
4528 4529 4530 4531 4532
	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;
4533 4534
	int ret;

4535 4536 4537
	rbd_assert(spec->pool_id != CEPH_NOPOOL);
	rbd_assert(spec->image_id);
	rbd_assert(spec->snap_id != CEPH_NOSNAP);
4538

4539
	/* Get the pool name; we have to make our own copy of this */
4540

4541 4542 4543
	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);
4544 4545
		return -EIO;
	}
4546 4547
	pool_name = kstrdup(pool_name, GFP_KERNEL);
	if (!pool_name)
4548 4549 4550 4551
		return -ENOMEM;

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

4552 4553
	image_name = rbd_dev_image_name(rbd_dev);
	if (!image_name)
A
Alex Elder 已提交
4554
		rbd_warn(rbd_dev, "unable to get image name");
4555

4556
	/* Fetch the snapshot name */
4557

4558
	snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4559 4560
	if (IS_ERR(snap_name)) {
		ret = PTR_ERR(snap_name);
4561
		goto out_err;
4562 4563 4564 4565 4566
	}

	spec->pool_name = pool_name;
	spec->image_name = image_name;
	spec->snap_name = snap_name;
4567 4568

	return 0;
4569

4570
out_err:
4571 4572
	kfree(image_name);
	kfree(pool_name);
4573 4574 4575
	return ret;
}

A
Alex Elder 已提交
4576
static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599
{
	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;

4600
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4601
				"rbd", "get_snapcontext", NULL, 0,
4602
				reply_buf, size);
4603
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4604 4605 4606 4607
	if (ret < 0)
		goto out;

	p = reply_buf;
4608 4609
	end = reply_buf + ret;
	ret = -ERANGE;
4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625
	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;
4626
	ret = 0;
4627

4628
	snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4629 4630 4631 4632 4633 4634 4635 4636
	if (!snapc) {
		ret = -ENOMEM;
		goto out;
	}
	snapc->seq = seq;
	for (i = 0; i < snap_count; i++)
		snapc->snaps[i] = ceph_decode_64(&p);

4637
	ceph_put_snap_context(rbd_dev->header.snapc);
4638 4639 4640
	rbd_dev->header.snapc = snapc;

	dout("  snap context seq = %llu, snap_count = %u\n",
4641
		(unsigned long long)seq, (unsigned int)snap_count);
4642 4643 4644
out:
	kfree(reply_buf);

4645
	return ret;
4646 4647
}

4648 4649
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
					u64 snap_id)
A
Alex Elder 已提交
4650 4651 4652
{
	size_t size;
	void *reply_buf;
4653
	__le64 snapid;
A
Alex Elder 已提交
4654 4655 4656 4657 4658 4659 4660 4661 4662 4663
	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);

4664
	snapid = cpu_to_le64(snap_id);
4665
	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
A
Alex Elder 已提交
4666
				"rbd", "get_snapshot_name",
4667
				&snapid, sizeof (snapid),
4668
				reply_buf, size);
4669
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4670 4671
	if (ret < 0) {
		snap_name = ERR_PTR(ret);
A
Alex Elder 已提交
4672
		goto out;
4673
	}
A
Alex Elder 已提交
4674 4675

	p = reply_buf;
4676
	end = reply_buf + ret;
A
Alex Elder 已提交
4677
	snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4678
	if (IS_ERR(snap_name))
A
Alex Elder 已提交
4679 4680
		goto out;

4681
	dout("  snap_id 0x%016llx snap_name = %s\n",
4682
		(unsigned long long)snap_id, snap_name);
A
Alex Elder 已提交
4683 4684 4685
out:
	kfree(reply_buf);

4686
	return snap_name;
A
Alex Elder 已提交
4687 4688
}

4689
static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
4690
{
4691
	bool first_time = rbd_dev->header.object_prefix == NULL;
A
Alex Elder 已提交
4692 4693
	int ret;

4694 4695
	ret = rbd_dev_v2_image_size(rbd_dev);
	if (ret)
4696
		return ret;
4697

4698 4699 4700
	if (first_time) {
		ret = rbd_dev_v2_header_onetime(rbd_dev);
		if (ret)
4701
			return ret;
4702 4703
	}

A
Alex Elder 已提交
4704
	ret = rbd_dev_v2_snap_context(rbd_dev);
A
Alex Elder 已提交
4705 4706 4707 4708 4709
	dout("rbd_dev_v2_snap_context returned %d\n", ret);

	return ret;
}

4710 4711 4712 4713 4714 4715 4716 4717 4718 4719
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);
}

4720 4721 4722
static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
{
	struct device *dev;
4723
	int ret;
4724

4725
	dev = &rbd_dev->dev;
4726 4727 4728
	dev->bus = &rbd_bus_type;
	dev->type = &rbd_device_type;
	dev->parent = &rbd_root_dev;
4729
	dev->release = rbd_dev_device_release;
A
Alex Elder 已提交
4730
	dev_set_name(dev, "%d", rbd_dev->dev_id);
4731 4732 4733
	ret = device_register(dev);

	return ret;
4734 4735
}

4736 4737 4738 4739 4740
static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
{
	device_unregister(&rbd_dev->dev);
}

4741
/*
4742
 * Get a unique rbd identifier for the given new rbd_dev, and add
4743
 * the rbd_dev to the global list.
4744
 */
4745
static int rbd_dev_id_get(struct rbd_device *rbd_dev)
4746
{
4747 4748
	int new_dev_id;

4749 4750 4751
	new_dev_id = ida_simple_get(&rbd_dev_id_ida,
				    0, minor_to_rbd_dev_id(1 << MINORBITS),
				    GFP_KERNEL);
4752 4753 4754 4755
	if (new_dev_id < 0)
		return new_dev_id;

	rbd_dev->dev_id = new_dev_id;
4756 4757 4758 4759

	spin_lock(&rbd_dev_list_lock);
	list_add_tail(&rbd_dev->node, &rbd_dev_list);
	spin_unlock(&rbd_dev_list_lock);
4760

4761
	dout("rbd_dev %p given dev id %d\n", rbd_dev, rbd_dev->dev_id);
4762 4763

	return 0;
4764
}
4765

4766
/*
4767 4768
 * Remove an rbd_dev from the global list, and record that its
 * identifier is no longer in use.
4769
 */
A
Alex Elder 已提交
4770
static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4771
{
4772 4773 4774
	spin_lock(&rbd_dev_list_lock);
	list_del_init(&rbd_dev->node);
	spin_unlock(&rbd_dev_list_lock);
4775

4776 4777 4778
	ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);

	dout("rbd_dev %p released dev id %d\n", rbd_dev, rbd_dev->dev_id);
4779 4780
}

4781 4782 4783
/*
 * 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
4784 4785
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799
 */
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
4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821
/*
 * 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
4822
	dup = kmemdup(*buf, len + 1, GFP_KERNEL);
A
Alex Elder 已提交
4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833
	if (!dup)
		return NULL;
	*(dup + len) = '\0';
	*buf += len;

	if (lenp)
		*lenp = len;

	return dup;
}

4834
/*
4835 4836 4837 4838
 * 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
4839
 *
4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866 4867 4868 4869 4870 4871 4872 4873
 * 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.
4874
 */
4875
static int rbd_add_parse_args(const char *buf,
4876
				struct ceph_options **ceph_opts,
4877 4878
				struct rbd_options **opts,
				struct rbd_spec **rbd_spec)
4879
{
A
Alex Elder 已提交
4880
	size_t len;
4881
	char *options;
4882
	const char *mon_addrs;
4883
	char *snap_name;
4884
	size_t mon_addrs_size;
4885
	struct rbd_spec *spec = NULL;
4886
	struct rbd_options *rbd_opts = NULL;
4887
	struct ceph_options *copts;
4888
	int ret;
4889 4890 4891

	/* The first four tokens are required */

4892
	len = next_token(&buf);
4893 4894 4895 4896
	if (!len) {
		rbd_warn(NULL, "no monitor address(es) provided");
		return -EINVAL;
	}
4897
	mon_addrs = buf;
4898
	mon_addrs_size = len + 1;
4899
	buf += len;
4900

4901
	ret = -EINVAL;
4902 4903
	options = dup_token(&buf, NULL);
	if (!options)
4904
		return -ENOMEM;
4905 4906 4907 4908
	if (!*options) {
		rbd_warn(NULL, "no options provided");
		goto out_err;
	}
4909

4910 4911
	spec = rbd_spec_alloc();
	if (!spec)
4912
		goto out_mem;
4913 4914 4915 4916

	spec->pool_name = dup_token(&buf, NULL);
	if (!spec->pool_name)
		goto out_mem;
4917 4918 4919 4920
	if (!*spec->pool_name) {
		rbd_warn(NULL, "no pool name provided");
		goto out_err;
	}
4921

A
Alex Elder 已提交
4922
	spec->image_name = dup_token(&buf, NULL);
4923
	if (!spec->image_name)
4924
		goto out_mem;
4925 4926 4927 4928
	if (!*spec->image_name) {
		rbd_warn(NULL, "no image name provided");
		goto out_err;
	}
4929

4930 4931 4932 4933
	/*
	 * Snapshot name is optional; default is to use "-"
	 * (indicating the head/no snapshot).
	 */
4934
	len = next_token(&buf);
4935
	if (!len) {
4936 4937
		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4938
	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
4939
		ret = -ENAMETOOLONG;
4940
		goto out_err;
4941
	}
4942 4943
	snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
	if (!snap_name)
4944
		goto out_mem;
4945 4946
	*(snap_name + len) = '\0';
	spec->snap_name = snap_name;
A
Alex Elder 已提交
4947

4948
	/* Initialize all rbd options to the defaults */
4949

4950 4951 4952 4953 4954
	rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
	if (!rbd_opts)
		goto out_mem;

	rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
A
Alex Elder 已提交
4955

4956
	copts = ceph_parse_options(options, mon_addrs,
4957
					mon_addrs + mon_addrs_size - 1,
4958
					parse_rbd_opts_token, rbd_opts);
4959 4960
	if (IS_ERR(copts)) {
		ret = PTR_ERR(copts);
4961 4962
		goto out_err;
	}
4963 4964 4965
	kfree(options);

	*ceph_opts = copts;
4966
	*opts = rbd_opts;
4967
	*rbd_spec = spec;
4968

4969
	return 0;
4970
out_mem:
4971
	ret = -ENOMEM;
A
Alex Elder 已提交
4972
out_err:
4973 4974
	kfree(rbd_opts);
	rbd_spec_put(spec);
4975
	kfree(options);
A
Alex Elder 已提交
4976

4977
	return ret;
4978 4979
}

4980 4981 4982 4983 4984
/*
 * Return pool id (>= 0) or a negative error code.
 */
static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
{
4985
	struct ceph_options *opts = rbdc->client->options;
4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 5000
	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) {
		ret = ceph_monc_do_get_version(&rbdc->client->monc, "osdmap",
					       &newest_epoch);
		if (ret < 0)
			return ret;

		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
			ceph_monc_request_next_osdmap(&rbdc->client->monc);
			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5001 5002
						     newest_epoch,
						     opts->mount_timeout);
5003 5004 5005 5006 5007 5008 5009 5010 5011 5012
			goto again;
		} else {
			/* the osdmap we have is new enough */
			return -ENOENT;
		}
	}

	return ret;
}

A
Alex Elder 已提交
5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032
/*
 * 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;
	char *object_name;
	void *response;
5033
	char *image_id;
5034

A
Alex Elder 已提交
5035 5036 5037
	/*
	 * When probing a parent image, the image id is already
	 * known (and the image name likely is not).  There's no
5038 5039
	 * 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
5040
	 */
5041 5042 5043
	if (rbd_dev->spec->image_id) {
		rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;

A
Alex Elder 已提交
5044
		return 0;
5045
	}
A
Alex Elder 已提交
5046

A
Alex Elder 已提交
5047 5048 5049 5050
	/*
	 * First, see if the format 2 image id file exists, and if
	 * so, get the image's persistent id from it.
	 */
A
Alex Elder 已提交
5051
	size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
A
Alex Elder 已提交
5052 5053 5054
	object_name = kmalloc(size, GFP_NOIO);
	if (!object_name)
		return -ENOMEM;
5055
	sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
A
Alex Elder 已提交
5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066
	dout("rbd id object name is %s\n", object_name);

	/* 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;
	}

5067 5068
	/* If it doesn't exist we'll assume it's a format 1 image */

5069
	ret = rbd_obj_method_sync(rbd_dev, object_name,
5070
				"rbd", "get_id", NULL, 0,
5071
				response, RBD_IMAGE_ID_LEN_MAX);
5072
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5073 5074 5075 5076 5077
	if (ret == -ENOENT) {
		image_id = kstrdup("", GFP_KERNEL);
		ret = image_id ? 0 : -ENOMEM;
		if (!ret)
			rbd_dev->image_format = 1;
5078
	} else if (ret >= 0) {
5079 5080 5081
		void *p = response;

		image_id = ceph_extract_encoded_string(&p, p + ret,
A
Alex Elder 已提交
5082
						NULL, GFP_NOIO);
5083
		ret = PTR_ERR_OR_ZERO(image_id);
5084 5085 5086 5087 5088 5089 5090
		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
5091 5092 5093 5094 5095 5096 5097 5098
	}
out:
	kfree(response);
	kfree(object_name);

	return ret;
}

A
Alex Elder 已提交
5099 5100 5101 5102
/*
 * Undo whatever state changes are made by v1 or v2 header info
 * call.
 */
A
Alex Elder 已提交
5103 5104 5105 5106
static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
{
	struct rbd_image_header	*header;

5107
	rbd_dev_parent_put(rbd_dev);
A
Alex Elder 已提交
5108 5109 5110 5111

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

	header = &rbd_dev->header;
5112
	ceph_put_snap_context(header->snapc);
A
Alex Elder 已提交
5113 5114 5115 5116 5117 5118
	kfree(header->snap_sizes);
	kfree(header->snap_names);
	kfree(header->object_prefix);
	memset(header, 0, sizeof (*header));
}

5119
static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5120 5121 5122
{
	int ret;

5123
	ret = rbd_dev_v2_object_prefix(rbd_dev);
5124
	if (ret)
5125 5126
		goto out_err;

5127 5128 5129 5130
	/*
	 * Get the and check features for the image.  Currently the
	 * features are assumed to never change.
	 */
5131
	ret = rbd_dev_v2_features(rbd_dev);
5132
	if (ret)
5133
		goto out_err;
5134

5135 5136 5137 5138 5139 5140 5141
	/* 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;
	}
5142
	/* No support for crypto and compression type format 2 images */
5143

A
Alex Elder 已提交
5144
	return 0;
5145
out_err:
A
Alex Elder 已提交
5146
	rbd_dev->header.features = 0;
5147 5148
	kfree(rbd_dev->header.object_prefix);
	rbd_dev->header.object_prefix = NULL;
5149 5150

	return ret;
5151 5152
}

5153
static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
A
Alex Elder 已提交
5154
{
5155
	struct rbd_device *parent = NULL;
5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174
	struct rbd_spec *parent_spec;
	struct rbd_client *rbdc;
	int ret;

	if (!rbd_dev->parent_spec)
		return 0;
	/*
	 * We need to pass a reference to the client and the parent
	 * spec when creating the parent rbd_dev.  Images related by
	 * parent/child relationships always share both.
	 */
	parent_spec = rbd_spec_get(rbd_dev->parent_spec);
	rbdc = __rbd_get_client(rbd_dev->rbd_client);

	ret = -ENOMEM;
	parent = rbd_dev_create(rbdc, parent_spec);
	if (!parent)
		goto out_err;

5175
	ret = rbd_dev_image_probe(parent, false);
5176 5177 5178
	if (ret < 0)
		goto out_err;
	rbd_dev->parent = parent;
5179
	atomic_set(&rbd_dev->parent_ref, 1);
5180 5181 5182 5183

	return 0;
out_err:
	if (parent) {
A
Alex Elder 已提交
5184
		rbd_dev_unparent(rbd_dev);
5185 5186 5187 5188 5189 5190 5191 5192 5193 5194
		kfree(rbd_dev->header_name);
		rbd_dev_destroy(parent);
	} else {
		rbd_put_client(rbdc);
		rbd_spec_put(parent_spec);
	}

	return ret;
}

5195
static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5196
{
A
Alex Elder 已提交
5197
	int ret;
A
Alex Elder 已提交
5198

5199 5200 5201 5202 5203
	/* Get an id and fill in device name. */

	ret = rbd_dev_id_get(rbd_dev);
	if (ret)
		return ret;
A
Alex Elder 已提交
5204 5205 5206 5207 5208

	BUILD_BUG_ON(DEV_NAME_LEN
			< sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
	sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);

5209
	/* Record our major and minor device numbers. */
A
Alex Elder 已提交
5210

5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221
	if (!single_major) {
		ret = register_blkdev(0, rbd_dev->name);
		if (ret < 0)
			goto err_out_id;

		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
5222 5223 5224 5225 5226 5227 5228

	/* Set up the blkdev mapping. */

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

5229
	ret = rbd_dev_mapping_set(rbd_dev);
A
Alex Elder 已提交
5230 5231
	if (ret)
		goto err_out_disk;
I
Ilya Dryomov 已提交
5232

5233
	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5234
	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
5235 5236 5237

	ret = rbd_bus_add_dev(rbd_dev);
	if (ret)
5238
		goto err_out_mapping;
A
Alex Elder 已提交
5239 5240 5241

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

5242
	set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
A
Alex Elder 已提交
5243 5244 5245 5246 5247 5248
	add_disk(rbd_dev->disk);

	pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
		(unsigned long long) rbd_dev->mapping.size);

	return ret;
5249

5250 5251
err_out_mapping:
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5252 5253 5254
err_out_disk:
	rbd_free_disk(rbd_dev);
err_out_blkdev:
5255 5256
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
A
Alex Elder 已提交
5257 5258
err_out_id:
	rbd_dev_id_put(rbd_dev);
A
Alex Elder 已提交
5259
	rbd_dev_mapping_clear(rbd_dev);
A
Alex Elder 已提交
5260 5261 5262 5263

	return ret;
}

A
Alex Elder 已提交
5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290
static int rbd_dev_header_name(struct rbd_device *rbd_dev)
{
	struct rbd_spec *spec = rbd_dev->spec;
	size_t size;

	/* 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)
		size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
	else
		size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);

	rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
	if (!rbd_dev->header_name)
		return -ENOMEM;

	if (rbd_dev->image_format == 1)
		sprintf(rbd_dev->header_name, "%s%s",
			spec->image_name, RBD_SUFFIX);
	else
		sprintf(rbd_dev->header_name, "%s%s",
			RBD_HEADER_PREFIX, spec->image_id);
	return 0;
}

5291 5292
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5293
	rbd_dev_unprobe(rbd_dev);
5294
	kfree(rbd_dev->header_name);
A
Alex Elder 已提交
5295 5296 5297 5298 5299
	rbd_dev->header_name = NULL;
	rbd_dev->image_format = 0;
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;

5300 5301 5302
	rbd_dev_destroy(rbd_dev);
}

5303 5304
/*
 * Probe for the existence of the header object for the given rbd
5305 5306 5307
 * 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.
5308
 */
5309
static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping)
5310 5311 5312 5313
{
	int ret;

	/*
A
Alex Elder 已提交
5314 5315 5316 5317
	 * 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.
5318 5319 5320
	 */
	ret = rbd_dev_image_id(rbd_dev);
	if (ret)
5321 5322
		return ret;

A
Alex Elder 已提交
5323 5324 5325 5326
	ret = rbd_dev_header_name(rbd_dev);
	if (ret)
		goto err_out_format;

5327
	if (mapping) {
5328
		ret = rbd_dev_header_watch_sync(rbd_dev);
5329 5330 5331 5332 5333
		if (ret) {
			if (ret == -ENOENT)
				pr_info("image %s/%s does not exist\n",
					rbd_dev->spec->pool_name,
					rbd_dev->spec->image_name);
5334
			goto out_header_name;
5335
		}
5336
	}
5337

5338
	ret = rbd_dev_header_info(rbd_dev);
5339
	if (ret)
5340
		goto err_out_watch;
A
Alex Elder 已提交
5341

5342 5343 5344 5345 5346 5347 5348 5349 5350 5351
	/*
	 * 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.
	 */
	if (mapping)
		ret = rbd_spec_fill_snap_id(rbd_dev);
	else
		ret = rbd_spec_fill_names(rbd_dev);
5352 5353 5354 5355 5356 5357
	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
5358
		goto err_out_probe;
5359
	}
5360

5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374
	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.
		 */
		if (mapping && rbd_dev->parent_spec)
			rbd_warn(rbd_dev,
				 "WARNING: kernel layering is EXPERIMENTAL!");
	}

5375
	ret = rbd_dev_probe_parent(rbd_dev);
A
Alex Elder 已提交
5376 5377 5378 5379 5380 5381
	if (ret)
		goto err_out_probe;

	dout("discovered format %u image, header name is %s\n",
		rbd_dev->image_format, rbd_dev->header_name);
	return 0;
5382

A
Alex Elder 已提交
5383 5384
err_out_probe:
	rbd_dev_unprobe(rbd_dev);
5385
err_out_watch:
5386 5387
	if (mapping)
		rbd_dev_header_unwatch_sync(rbd_dev);
A
Alex Elder 已提交
5388 5389 5390 5391 5392
out_header_name:
	kfree(rbd_dev->header_name);
	rbd_dev->header_name = NULL;
err_out_format:
	rbd_dev->image_format = 0;
5393 5394
	kfree(rbd_dev->spec->image_id);
	rbd_dev->spec->image_id = NULL;
5395 5396 5397
	return ret;
}

5398 5399 5400
static ssize_t do_rbd_add(struct bus_type *bus,
			  const char *buf,
			  size_t count)
5401
{
5402
	struct rbd_device *rbd_dev = NULL;
5403
	struct ceph_options *ceph_opts = NULL;
5404
	struct rbd_options *rbd_opts = NULL;
5405
	struct rbd_spec *spec = NULL;
5406
	struct rbd_client *rbdc;
5407
	bool read_only;
5408
	int rc = -ENOMEM;
5409 5410 5411 5412 5413

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

	/* parse add command */
5414
	rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
5415
	if (rc < 0)
5416
		goto err_out_module;
5417 5418 5419
	read_only = rbd_opts->read_only;
	kfree(rbd_opts);
	rbd_opts = NULL;	/* done with this */
5420

5421 5422 5423
	rbdc = rbd_get_client(ceph_opts);
	if (IS_ERR(rbdc)) {
		rc = PTR_ERR(rbdc);
5424
		goto err_out_args;
5425
	}
5426 5427

	/* pick the pool */
5428
	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
5429 5430 5431
	if (rc < 0) {
		if (rc == -ENOENT)
			pr_info("pool %s does not exist\n", spec->pool_name);
5432
		goto err_out_client;
5433
	}
A
Alex Elder 已提交
5434
	spec->pool_id = (u64)rc;
5435

5436 5437
	/* The ceph file layout needs to fit pool id in 32 bits */

A
Alex Elder 已提交
5438
	if (spec->pool_id > (u64)U32_MAX) {
5439
		rbd_warn(NULL, "pool id too large (%llu > %u)",
A
Alex Elder 已提交
5440
				(unsigned long long)spec->pool_id, U32_MAX);
5441 5442 5443 5444
		rc = -EIO;
		goto err_out_client;
	}

5445
	rbd_dev = rbd_dev_create(rbdc, spec);
5446 5447
	if (!rbd_dev)
		goto err_out_client;
5448 5449
	rbdc = NULL;		/* rbd_dev now owns this */
	spec = NULL;		/* rbd_dev now owns this */
5450

5451
	rc = rbd_dev_image_probe(rbd_dev, true);
5452
	if (rc < 0)
5453
		goto err_out_rbd_dev;
5454

5455 5456 5457 5458 5459 5460
	/* If we are mapping a snapshot it must be marked read-only */

	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
		read_only = true;
	rbd_dev->mapping.read_only = read_only;

5461
	rc = rbd_dev_device_setup(rbd_dev);
A
Alex Elder 已提交
5462
	if (rc) {
5463 5464 5465 5466 5467 5468
		/*
		 * rbd_dev_header_unwatch_sync() can't be moved into
		 * rbd_dev_image_release() without refactoring, see
		 * commit 1f3ef78861ac.
		 */
		rbd_dev_header_unwatch_sync(rbd_dev);
A
Alex Elder 已提交
5469 5470 5471 5472 5473
		rbd_dev_image_release(rbd_dev);
		goto err_out_module;
	}

	return count;
5474

5475 5476
err_out_rbd_dev:
	rbd_dev_destroy(rbd_dev);
5477
err_out_client:
5478
	rbd_put_client(rbdc);
5479
err_out_args:
5480
	rbd_spec_put(spec);
5481 5482
err_out_module:
	module_put(THIS_MODULE);
5483

5484
	dout("Error adding device %s\n", buf);
5485

A
Alex Elder 已提交
5486
	return (ssize_t)rc;
5487 5488
}

5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505
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);
}

5506
static void rbd_dev_device_release(struct device *dev)
5507
{
A
Alex Elder 已提交
5508
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5509 5510

	rbd_free_disk(rbd_dev);
5511
	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
A
Alex Elder 已提交
5512
	rbd_dev_mapping_clear(rbd_dev);
5513 5514
	if (!single_major)
		unregister_blkdev(rbd_dev->major, rbd_dev->name);
A
Alex Elder 已提交
5515
	rbd_dev_id_put(rbd_dev);
A
Alex Elder 已提交
5516
	rbd_dev_mapping_clear(rbd_dev);
5517 5518
}

5519 5520
static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
5521
	while (rbd_dev->parent) {
5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533
		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
5534
		rbd_assert(second);
5535
		rbd_dev_image_release(second);
A
Alex Elder 已提交
5536 5537 5538 5539
		first->parent = NULL;
		first->parent_overlap = 0;

		rbd_assert(first->parent_spec);
5540 5541 5542 5543 5544
		rbd_spec_put(first->parent_spec);
		first->parent_spec = NULL;
	}
}

5545 5546 5547
static ssize_t do_rbd_remove(struct bus_type *bus,
			     const char *buf,
			     size_t count)
5548 5549
{
	struct rbd_device *rbd_dev = NULL;
5550 5551
	struct list_head *tmp;
	int dev_id;
5552
	unsigned long ul;
5553
	bool already = false;
5554
	int ret;
5555

5556
	ret = kstrtoul(buf, 10, &ul);
5557 5558
	if (ret)
		return ret;
5559 5560

	/* convert to int; abort if we lost anything in the conversion */
5561 5562
	dev_id = (int)ul;
	if (dev_id != ul)
5563 5564
		return -EINVAL;

5565 5566 5567 5568 5569 5570 5571 5572
	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;
		}
5573
	}
5574 5575 5576 5577 5578
	if (!ret) {
		spin_lock_irq(&rbd_dev->lock);
		if (rbd_dev->open_count)
			ret = -EBUSY;
		else
5579 5580
			already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
							&rbd_dev->flags);
5581 5582 5583
		spin_unlock_irq(&rbd_dev->lock);
	}
	spin_unlock(&rbd_dev_list_lock);
5584
	if (ret < 0 || already)
5585
		return ret;
5586

5587
	rbd_dev_header_unwatch_sync(rbd_dev);
5588 5589 5590 5591 5592 5593
	/*
	 * flush remaining watch callbacks - these must be complete
	 * before the osd_client is shutdown
	 */
	dout("%s: flushing notifies", __func__);
	ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
5594

5595 5596 5597 5598 5599 5600 5601
	/*
	 * Don't free anything from rbd_dev->disk until after all
	 * notifies are completely processed. Otherwise
	 * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
	 * in a potential use after free of rbd_dev->disk or rbd_dev.
	 */
	rbd_bus_del_dev(rbd_dev);
5602
	rbd_dev_image_release(rbd_dev);
A
Alex Elder 已提交
5603
	module_put(THIS_MODULE);
A
Alex Elder 已提交
5604

5605
	return count;
5606 5607
}

5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624
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);
}

5625 5626
/*
 * create control files in sysfs
5627
 * /sys/bus/rbd/...
5628 5629 5630
 */
static int rbd_sysfs_init(void)
{
5631
	int ret;
5632

5633
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
5634
	if (ret < 0)
5635
		return ret;
5636

5637 5638 5639
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
5640 5641 5642 5643 5644 5645

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
5646
	bus_unregister(&rbd_bus_type);
5647
	device_unregister(&rbd_root_dev);
5648 5649
}

5650 5651 5652 5653 5654 5655 5656
static int rbd_slab_init(void)
{
	rbd_assert(!rbd_img_request_cache);
	rbd_img_request_cache = kmem_cache_create("rbd_img_request",
					sizeof (struct rbd_img_request),
					__alignof__(struct rbd_img_request),
					0, NULL);
5657 5658 5659 5660 5661 5662 5663 5664
	if (!rbd_img_request_cache)
		return -ENOMEM;

	rbd_assert(!rbd_obj_request_cache);
	rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
					sizeof (struct rbd_obj_request),
					__alignof__(struct rbd_obj_request),
					0, NULL);
5665 5666 5667 5668 5669
	if (!rbd_obj_request_cache)
		goto out_err;

	rbd_assert(!rbd_segment_name_cache);
	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
5670
					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
5671
	if (rbd_segment_name_cache)
5672
		return 0;
5673 5674 5675 5676 5677
out_err:
	if (rbd_obj_request_cache) {
		kmem_cache_destroy(rbd_obj_request_cache);
		rbd_obj_request_cache = NULL;
	}
5678

5679 5680 5681
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;

5682 5683 5684 5685 5686
	return -ENOMEM;
}

static void rbd_slab_exit(void)
{
5687 5688 5689 5690
	rbd_assert(rbd_segment_name_cache);
	kmem_cache_destroy(rbd_segment_name_cache);
	rbd_segment_name_cache = NULL;

5691 5692 5693 5694
	rbd_assert(rbd_obj_request_cache);
	kmem_cache_destroy(rbd_obj_request_cache);
	rbd_obj_request_cache = NULL;

5695 5696 5697 5698 5699
	rbd_assert(rbd_img_request_cache);
	kmem_cache_destroy(rbd_img_request_cache);
	rbd_img_request_cache = NULL;
}

A
Alex Elder 已提交
5700
static int __init rbd_init(void)
5701 5702 5703
{
	int rc;

5704 5705 5706 5707
	if (!libceph_compatible(NULL)) {
		rbd_warn(NULL, "libceph incompatibility (quitting)");
		return -EINVAL;
	}
I
Ilya Dryomov 已提交
5708

5709
	rc = rbd_slab_init();
5710 5711
	if (rc)
		return rc;
I
Ilya Dryomov 已提交
5712

5713 5714
	/*
	 * The number of active work items is limited by the number of
I
Ilya Dryomov 已提交
5715
	 * rbd devices * queue depth, so leave @max_active at default.
5716 5717 5718 5719 5720 5721 5722
	 */
	rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
	if (!rbd_wq) {
		rc = -ENOMEM;
		goto err_out_slab;
	}

5723 5724 5725 5726
	if (single_major) {
		rbd_major = register_blkdev(0, RBD_DRV_NAME);
		if (rbd_major < 0) {
			rc = rbd_major;
5727
			goto err_out_wq;
5728 5729 5730
		}
	}

5731 5732
	rc = rbd_sysfs_init();
	if (rc)
5733 5734 5735 5736 5737 5738
		goto err_out_blkdev;

	if (single_major)
		pr_info("loaded (major %d)\n", rbd_major);
	else
		pr_info("loaded\n");
5739

I
Ilya Dryomov 已提交
5740 5741
	return 0;

5742 5743 5744
err_out_blkdev:
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
5745 5746
err_out_wq:
	destroy_workqueue(rbd_wq);
I
Ilya Dryomov 已提交
5747 5748
err_out_slab:
	rbd_slab_exit();
5749
	return rc;
5750 5751
}

A
Alex Elder 已提交
5752
static void __exit rbd_exit(void)
5753
{
I
Ilya Dryomov 已提交
5754
	ida_destroy(&rbd_dev_id_ida);
5755
	rbd_sysfs_cleanup();
5756 5757
	if (single_major)
		unregister_blkdev(rbd_major, RBD_DRV_NAME);
5758
	destroy_workqueue(rbd_wq);
5759
	rbd_slab_exit();
5760 5761 5762 5763 5764
}

module_init(rbd_init);
module_exit(rbd_exit);

A
Alex Elder 已提交
5765
MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
5766 5767 5768 5769 5770
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>");

5771
MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
5772
MODULE_LICENSE("GPL");