rbd.c 58.2 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/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>

#include "rbd_types.h"

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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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#define RBD_DRV_NAME "rbd"
#define RBD_DRV_NAME_LONG "rbd (rados block device)"
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#define RBD_MINORS_PER_MAJOR	256		/* max minors per blkdev */

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#define RBD_MAX_MD_NAME_LEN	(RBD_MAX_OBJ_NAME_LEN + sizeof(RBD_SUFFIX))
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#define RBD_MAX_POOL_NAME_LEN	64
#define RBD_MAX_SNAP_NAME_LEN	32
#define RBD_MAX_OPT_LEN		1024

#define RBD_SNAP_HEAD_NAME	"-"

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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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#define RBD_NOTIFY_TIMEOUT_DEFAULT 10

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/*
 * block device image metadata (in-memory version)
 */
struct rbd_image_header {
	u64 image_size;
	char block_name[32];
	__u8 obj_order;
	__u8 crypt_type;
	__u8 comp_type;
	struct ceph_snap_context *snapc;
	size_t snap_names_len;
	u64 snap_seq;
	u32 total_snaps;

	char *snap_names;
	u64 *snap_sizes;
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	u64 obj_version;
};

struct rbd_options {
	int	notify_timeout;
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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;
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	struct rbd_options	*rbd_opts;
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	struct kref		kref;
	struct list_head	node;
};

/*
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 * a request completion status
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 */
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struct rbd_req_status {
	int done;
	int rc;
	u64 bytes;
};

/*
 * a collection of requests
 */
struct rbd_req_coll {
	int			total;
	int			num_done;
	struct kref		kref;
	struct rbd_req_status	status[0];
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};

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/*
 * a single io request
 */
struct rbd_request {
	struct request		*rq;		/* blk layer request */
	struct bio		*bio;		/* cloned bio */
	struct page		**pages;	/* list of used pages */
	u64			len;
	int			coll_index;
	struct rbd_req_coll	*coll;
};

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struct rbd_snap {
	struct	device		dev;
	const char		*name;
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	u64			size;
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	struct list_head	node;
	u64			id;
};

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/*
 * a single device
 */
struct rbd_device {
	int			id;		/* blkdev unique id */

	int			major;		/* blkdev assigned major */
	struct gendisk		*disk;		/* blkdev's gendisk and rq */
	struct request_queue	*q;

	struct rbd_client	*rbd_client;

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

	spinlock_t		lock;		/* queue lock */

	struct rbd_image_header	header;
	char			obj[RBD_MAX_OBJ_NAME_LEN]; /* rbd image name */
	int			obj_len;
	char			obj_md_name[RBD_MAX_MD_NAME_LEN]; /* hdr nm. */
	char			pool_name[RBD_MAX_POOL_NAME_LEN];
	int			poolid;

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	struct ceph_osd_event   *watch_event;
	struct ceph_osd_request *watch_request;

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	/* protects updating the header */
	struct rw_semaphore     header_rwsem;
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	char                    snap_name[RBD_MAX_SNAP_NAME_LEN];
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	u64                     snap_id;	/* current snapshot id */
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	int read_only;

	struct list_head	node;
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	/* list of snapshots */
	struct list_head	snaps;

	/* sysfs related */
	struct device		dev;
};

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static DEFINE_MUTEX(ctl_mutex);	  /* Serialize open/close/setup/teardown */
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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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static int __rbd_init_snaps_header(struct rbd_device *rbd_dev);
static void rbd_dev_release(struct device *dev);
static ssize_t rbd_snap_add(struct device *dev,
			    struct device_attribute *attr,
			    const char *buf,
			    size_t count);
static void __rbd_remove_snap_dev(struct rbd_device *rbd_dev,
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				  struct rbd_snap *snap);
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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);

static struct bus_attribute rbd_bus_attrs[] = {
	__ATTR(add, S_IWUSR, NULL, rbd_add),
	__ATTR(remove, S_IWUSR, NULL, rbd_remove),
	__ATTR_NULL
};

static struct bus_type rbd_bus_type = {
	.name		= "rbd",
	.bus_attrs	= rbd_bus_attrs,
};

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 struct device *rbd_get_dev(struct rbd_device *rbd_dev)
{
	return get_device(&rbd_dev->dev);
}

static void rbd_put_dev(struct rbd_device *rbd_dev)
{
	put_device(&rbd_dev->dev);
}
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static int __rbd_refresh_header(struct rbd_device *rbd_dev);
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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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	rbd_get_dev(rbd_dev);

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	set_device_ro(bdev, rbd_dev->read_only);

	if ((mode & FMODE_WRITE) && rbd_dev->read_only)
		return -EROFS;

	return 0;
}

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static int rbd_release(struct gendisk *disk, fmode_t mode)
{
	struct rbd_device *rbd_dev = disk->private_data;

	rbd_put_dev(rbd_dev);

	return 0;
}

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static const struct block_device_operations rbd_bd_ops = {
	.owner			= THIS_MODULE,
	.open			= rbd_open,
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	.release		= rbd_release,
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};

/*
 * Initialize an rbd client instance.
 * We own *opt.
 */
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static struct rbd_client *rbd_client_create(struct ceph_options *opt,
					    struct rbd_options *rbd_opts)
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{
	struct rbd_client *rbdc;
	int ret = -ENOMEM;

	dout("rbd_client_create\n");
	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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	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);

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	rbdc->client = ceph_create_client(opt, rbdc, 0, 0);
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	if (IS_ERR(rbdc->client))
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		goto out_mutex;
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	opt = NULL; /* Now rbdc->client is responsible for opt */
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	ret = ceph_open_session(rbdc->client);
	if (ret < 0)
		goto out_err;

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	rbdc->rbd_opts = rbd_opts;

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	spin_lock(&rbd_client_list_lock);
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	list_add_tail(&rbdc->node, &rbd_client_list);
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	spin_unlock(&rbd_client_list_lock);
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	mutex_unlock(&ctl_mutex);

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	dout("rbd_client_create created %p\n", rbdc);
	return rbdc;

out_err:
	ceph_destroy_client(rbdc->client);
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out_mutex:
	mutex_unlock(&ctl_mutex);
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	kfree(rbdc);
out_opt:
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	if (opt)
		ceph_destroy_options(opt);
	return ERR_PTR(ret);
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}

/*
 * Find a ceph client with specific addr and configuration.
 */
static struct rbd_client *__rbd_client_find(struct ceph_options *opt)
{
	struct rbd_client *client_node;

	if (opt->flags & CEPH_OPT_NOSHARE)
		return NULL;

	list_for_each_entry(client_node, &rbd_client_list, node)
		if (ceph_compare_options(opt, client_node->client) == 0)
			return client_node;
	return NULL;
}

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/*
 * mount options
 */
enum {
	Opt_notify_timeout,
	Opt_last_int,
	/* int args above */
	Opt_last_string,
	/* string args above */
};

static match_table_t rbdopt_tokens = {
	{Opt_notify_timeout, "notify_timeout=%d"},
	/* int args above */
	/* string args above */
	{-1, NULL}
};

static int parse_rbd_opts_token(char *c, void *private)
{
	struct rbd_options *rbdopt = private;
	substring_t argstr[MAX_OPT_ARGS];
	int token, intval, ret;

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	token = match_token(c, rbdopt_tokens, argstr);
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	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);
	} else {
		dout("got token %d\n", token);
	}

	switch (token) {
	case Opt_notify_timeout:
		rbdopt->notify_timeout = intval;
		break;
	default:
		BUG_ON(token);
	}
	return 0;
}

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/*
 * Get a ceph client with specific addr and configuration, if one does
 * not exist create it.
 */
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static struct rbd_client *rbd_get_client(const char *mon_addr,
					 size_t mon_addr_len,
					 char *options)
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{
	struct rbd_client *rbdc;
	struct ceph_options *opt;
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	struct rbd_options *rbd_opts;

	rbd_opts = kzalloc(sizeof(*rbd_opts), GFP_KERNEL);
	if (!rbd_opts)
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		return ERR_PTR(-ENOMEM);
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	rbd_opts->notify_timeout = RBD_NOTIFY_TIMEOUT_DEFAULT;
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	opt = ceph_parse_options(options, mon_addr,
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				mon_addr + mon_addr_len,
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				parse_rbd_opts_token, rbd_opts);
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	if (IS_ERR(opt)) {
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		kfree(rbd_opts);
		return ERR_CAST(opt);
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	}
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	spin_lock(&rbd_client_list_lock);
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	rbdc = __rbd_client_find(opt);
	if (rbdc) {
		/* using an existing client */
		kref_get(&rbdc->kref);
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		spin_unlock(&rbd_client_list_lock);
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		ceph_destroy_options(opt);
		kfree(rbd_opts);

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		return rbdc;
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	}
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	spin_unlock(&rbd_client_list_lock);
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	rbdc = rbd_client_create(opt, rbd_opts);
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	if (IS_ERR(rbdc))
		kfree(rbd_opts);
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	return rbdc;
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}

/*
 * Destroy ceph client
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 *
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 * Caller must hold rbd_client_list_lock.
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 */
static void rbd_client_release(struct kref *kref)
{
	struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);

	dout("rbd_release_client %p\n", rbdc);
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	spin_lock(&rbd_client_list_lock);
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	list_del(&rbdc->node);
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	spin_unlock(&rbd_client_list_lock);
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	ceph_destroy_client(rbdc->client);
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	kfree(rbdc->rbd_opts);
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	kfree(rbdc);
}

/*
 * Drop reference to ceph client node. If it's not referenced anymore, release
 * it.
 */
static void rbd_put_client(struct rbd_device *rbd_dev)
{
	kref_put(&rbd_dev->rbd_client->kref, rbd_client_release);
	rbd_dev->rbd_client = NULL;
}

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/*
 * Destroy requests collection
 */
static void rbd_coll_release(struct kref *kref)
{
	struct rbd_req_coll *coll =
		container_of(kref, struct rbd_req_coll, kref);

	dout("rbd_coll_release %p\n", coll);
	kfree(coll);
}
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/*
 * Create a new header structure, translate header format from the on-disk
 * header.
 */
static int rbd_header_from_disk(struct rbd_image_header *header,
				 struct rbd_image_header_ondisk *ondisk,
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				 u32 allocated_snaps,
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				 gfp_t gfp_flags)
{
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	u32 i, snap_count;
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	if (memcmp(ondisk, RBD_HEADER_TEXT, sizeof(RBD_HEADER_TEXT)))
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		return -ENXIO;

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	snap_count = le32_to_cpu(ondisk->snap_count);
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	if (snap_count > (UINT_MAX - sizeof(struct ceph_snap_context))
			 / sizeof (*ondisk))
		return -EINVAL;
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	header->snapc = kmalloc(sizeof(struct ceph_snap_context) +
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				snap_count * sizeof (*ondisk),
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				gfp_flags);
	if (!header->snapc)
		return -ENOMEM;
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	header->snap_names_len = le64_to_cpu(ondisk->snap_names_len);
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	if (snap_count) {
		header->snap_names = kmalloc(header->snap_names_len,
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					     gfp_flags);
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		if (!header->snap_names)
			goto err_snapc;
		header->snap_sizes = kmalloc(snap_count * sizeof(u64),
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					     gfp_flags);
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		if (!header->snap_sizes)
			goto err_names;
	} else {
		header->snap_names = NULL;
		header->snap_sizes = NULL;
	}
	memcpy(header->block_name, ondisk->block_name,
	       sizeof(ondisk->block_name));

	header->image_size = le64_to_cpu(ondisk->image_size);
	header->obj_order = ondisk->options.order;
	header->crypt_type = ondisk->options.crypt_type;
	header->comp_type = ondisk->options.comp_type;

	atomic_set(&header->snapc->nref, 1);
	header->snap_seq = le64_to_cpu(ondisk->snap_seq);
	header->snapc->num_snaps = snap_count;
	header->total_snaps = snap_count;

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	if (snap_count && allocated_snaps == snap_count) {
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		for (i = 0; i < snap_count; i++) {
			header->snapc->snaps[i] =
				le64_to_cpu(ondisk->snaps[i].id);
			header->snap_sizes[i] =
				le64_to_cpu(ondisk->snaps[i].image_size);
		}

		/* copy snapshot names */
		memcpy(header->snap_names, &ondisk->snaps[i],
			header->snap_names_len);
	}

	return 0;

err_names:
	kfree(header->snap_names);
err_snapc:
	kfree(header->snapc);
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	return -ENOMEM;
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}

static int snap_by_name(struct rbd_image_header *header, const char *snap_name,
			u64 *seq, u64 *size)
{
	int i;
	char *p = header->snap_names;

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	for (i = 0; i < header->total_snaps; i++) {
		if (!strcmp(snap_name, p)) {
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			/* Found it.  Pass back its id and/or size */
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			if (seq)
				*seq = header->snapc->snaps[i];
			if (size)
				*size = header->snap_sizes[i];
			return i;
		}
		p += strlen(p) + 1;	/* Skip ahead to the next name */
	}
	return -ENOENT;
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}

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static int rbd_header_set_snap(struct rbd_device *dev, u64 *size)
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{
	struct rbd_image_header *header = &dev->header;
	struct ceph_snap_context *snapc = header->snapc;
	int ret = -ENOENT;

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	BUILD_BUG_ON(sizeof (dev->snap_name) < sizeof (RBD_SNAP_HEAD_NAME));

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	down_write(&dev->header_rwsem);
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	if (!memcmp(dev->snap_name, RBD_SNAP_HEAD_NAME,
		    sizeof (RBD_SNAP_HEAD_NAME))) {
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		if (header->total_snaps)
			snapc->seq = header->snap_seq;
		else
			snapc->seq = 0;
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		dev->snap_id = CEPH_NOSNAP;
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		dev->read_only = 0;
		if (size)
			*size = header->image_size;
	} else {
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		ret = snap_by_name(header, dev->snap_name, &snapc->seq, size);
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		if (ret < 0)
			goto done;
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		dev->snap_id = snapc->seq;
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		dev->read_only = 1;
	}

	ret = 0;
done:
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	up_write(&dev->header_rwsem);
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	return ret;
}

static void rbd_header_free(struct rbd_image_header *header)
{
	kfree(header->snapc);
	kfree(header->snap_names);
	kfree(header->snap_sizes);
}

/*
 * get the actual striped segment name, offset and length
 */
static u64 rbd_get_segment(struct rbd_image_header *header,
			   const char *block_name,
			   u64 ofs, u64 len,
			   char *seg_name, u64 *segofs)
{
	u64 seg = ofs >> header->obj_order;

	if (seg_name)
		snprintf(seg_name, RBD_MAX_SEG_NAME_LEN,
			 "%s.%012llx", block_name, seg);

	ofs = ofs & ((1 << header->obj_order) - 1);
	len = min_t(u64, len, (1 << header->obj_order) - ofs);

	if (segofs)
		*segofs = ofs;

	return len;
}

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static int rbd_get_num_segments(struct rbd_image_header *header,
				u64 ofs, u64 len)
{
	u64 start_seg = ofs >> header->obj_order;
	u64 end_seg = (ofs + len - 1) >> header->obj_order;
	return end_seg - start_seg + 1;
}

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/*
 * returns the size of an object in the image
 */
static u64 rbd_obj_bytes(struct rbd_image_header *header)
{
	return 1 << header->obj_order;
}

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/*
 * 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)
{
	struct bio_vec *bv;
	unsigned long flags;
	void *buf;
	int i;
	int pos = 0;

	while (chain) {
		bio_for_each_segment(bv, chain, i) {
			if (pos + bv->bv_len > start_ofs) {
				int remainder = max(start_ofs - pos, 0);
				buf = bvec_kmap_irq(bv, &flags);
				memset(buf + remainder, 0,
				       bv->bv_len - remainder);
691
				bvec_kunmap_irq(buf, &flags);
692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
			}
			pos += bv->bv_len;
		}

		chain = chain->bi_next;
	}
}

/*
 * bio_chain_clone - clone a chain of bios up to a certain length.
 * might return a bio_pair that will need to be released.
 */
static struct bio *bio_chain_clone(struct bio **old, struct bio **next,
				   struct bio_pair **bp,
				   int len, gfp_t gfpmask)
{
	struct bio *tmp, *old_chain = *old, *new_chain = NULL, *tail = NULL;
	int total = 0;

	if (*bp) {
		bio_pair_release(*bp);
		*bp = NULL;
	}

	while (old_chain && (total < len)) {
		tmp = bio_kmalloc(gfpmask, old_chain->bi_max_vecs);
		if (!tmp)
			goto err_out;

		if (total + old_chain->bi_size > len) {
			struct bio_pair *bp;

			/*
			 * this split can only happen with a single paged bio,
			 * split_bio will BUG_ON if this is not the case
			 */
			dout("bio_chain_clone split! total=%d remaining=%d"
			     "bi_size=%d\n",
			     (int)total, (int)len-total,
			     (int)old_chain->bi_size);

			/* split the bio. We'll release it either in the next
			   call, or it will have to be released outside */
A
Alex Elder 已提交
735
			bp = bio_split(old_chain, (len - total) / SECTOR_SIZE);
736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
			if (!bp)
				goto err_out;

			__bio_clone(tmp, &bp->bio1);

			*next = &bp->bio2;
		} else {
			__bio_clone(tmp, old_chain);
			*next = old_chain->bi_next;
		}

		tmp->bi_bdev = NULL;
		gfpmask &= ~__GFP_WAIT;
		tmp->bi_next = NULL;

		if (!new_chain) {
			new_chain = tail = tmp;
		} else {
			tail->bi_next = tmp;
			tail = tmp;
		}
		old_chain = old_chain->bi_next;

		total += tmp->bi_size;
	}

	BUG_ON(total < len);

	if (tail)
		tail->bi_next = NULL;

	*old = old_chain;

	return new_chain;

err_out:
	dout("bio_chain_clone with err\n");
	bio_chain_put(new_chain);
	return NULL;
}

/*
 * helpers for osd request op vectors.
 */
static int rbd_create_rw_ops(struct ceph_osd_req_op **ops,
			    int num_ops,
			    int opcode,
			    u32 payload_len)
{
	*ops = kzalloc(sizeof(struct ceph_osd_req_op) * (num_ops + 1),
		       GFP_NOIO);
	if (!*ops)
		return -ENOMEM;
	(*ops)[0].op = opcode;
	/*
	 * op extent offset and length will be set later on
	 * in calc_raw_layout()
	 */
	(*ops)[0].payload_len = payload_len;
	return 0;
}

static void rbd_destroy_ops(struct ceph_osd_req_op *ops)
{
	kfree(ops);
}

Y
Yehuda Sadeh 已提交
803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846
static void rbd_coll_end_req_index(struct request *rq,
				   struct rbd_req_coll *coll,
				   int index,
				   int ret, u64 len)
{
	struct request_queue *q;
	int min, max, i;

	dout("rbd_coll_end_req_index %p index %d ret %d len %lld\n",
	     coll, index, ret, len);

	if (!rq)
		return;

	if (!coll) {
		blk_end_request(rq, ret, len);
		return;
	}

	q = rq->q;

	spin_lock_irq(q->queue_lock);
	coll->status[index].done = 1;
	coll->status[index].rc = ret;
	coll->status[index].bytes = len;
	max = min = coll->num_done;
	while (max < coll->total && coll->status[max].done)
		max++;

	for (i = min; i<max; i++) {
		__blk_end_request(rq, coll->status[i].rc,
				  coll->status[i].bytes);
		coll->num_done++;
		kref_put(&coll->kref, rbd_coll_release);
	}
	spin_unlock_irq(q->queue_lock);
}

static void rbd_coll_end_req(struct rbd_request *req,
			     int ret, u64 len)
{
	rbd_coll_end_req_index(req->rq, req->coll, req->coll_index, ret, len);
}

847 848 849 850 851 852 853 854 855 856 857 858 859 860
/*
 * Send ceph osd request
 */
static int rbd_do_request(struct request *rq,
			  struct rbd_device *dev,
			  struct ceph_snap_context *snapc,
			  u64 snapid,
			  const char *obj, u64 ofs, u64 len,
			  struct bio *bio,
			  struct page **pages,
			  int num_pages,
			  int flags,
			  struct ceph_osd_req_op *ops,
			  int num_reply,
Y
Yehuda Sadeh 已提交
861 862
			  struct rbd_req_coll *coll,
			  int coll_index,
863
			  void (*rbd_cb)(struct ceph_osd_request *req,
864 865 866
					 struct ceph_msg *msg),
			  struct ceph_osd_request **linger_req,
			  u64 *ver)
867 868 869 870 871 872 873 874
{
	struct ceph_osd_request *req;
	struct ceph_file_layout *layout;
	int ret;
	u64 bno;
	struct timespec mtime = CURRENT_TIME;
	struct rbd_request *req_data;
	struct ceph_osd_request_head *reqhead;
875
	struct ceph_osd_client *osdc;
876 877

	req_data = kzalloc(sizeof(*req_data), GFP_NOIO);
Y
Yehuda Sadeh 已提交
878 879 880 881 882 883 884 885 886 887 888
	if (!req_data) {
		if (coll)
			rbd_coll_end_req_index(rq, coll, coll_index,
					       -ENOMEM, len);
		return -ENOMEM;
	}

	if (coll) {
		req_data->coll = coll;
		req_data->coll_index = coll_index;
	}
889

Y
Yehuda Sadeh 已提交
890
	dout("rbd_do_request obj=%s ofs=%lld len=%lld\n", obj, len, ofs);
891

892
	down_read(&dev->header_rwsem);
893

894 895 896
	osdc = &dev->rbd_client->client->osdc;
	req = ceph_osdc_alloc_request(osdc, flags, snapc, ops,
					false, GFP_NOIO, pages, bio);
897
	if (!req) {
898
		up_read(&dev->header_rwsem);
899
		ret = -ENOMEM;
900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
		goto done_pages;
	}

	req->r_callback = rbd_cb;

	req_data->rq = rq;
	req_data->bio = bio;
	req_data->pages = pages;
	req_data->len = len;

	req->r_priv = req_data;

	reqhead = req->r_request->front.iov_base;
	reqhead->snapid = cpu_to_le64(CEPH_NOSNAP);

	strncpy(req->r_oid, obj, sizeof(req->r_oid));
	req->r_oid_len = strlen(req->r_oid);

	layout = &req->r_file_layout;
	memset(layout, 0, sizeof(*layout));
	layout->fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
	layout->fl_stripe_count = cpu_to_le32(1);
	layout->fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
	layout->fl_pg_pool = cpu_to_le32(dev->poolid);
924 925
	ceph_calc_raw_layout(osdc, layout, snapid, ofs, &len, &bno,
				req, ops);
926 927 928 929 930 931

	ceph_osdc_build_request(req, ofs, &len,
				ops,
				snapc,
				&mtime,
				req->r_oid, req->r_oid_len);
932
	up_read(&dev->header_rwsem);
933

934
	if (linger_req) {
935
		ceph_osdc_set_request_linger(osdc, req);
936 937 938
		*linger_req = req;
	}

939
	ret = ceph_osdc_start_request(osdc, req, false);
940 941 942 943
	if (ret < 0)
		goto done_err;

	if (!rbd_cb) {
944
		ret = ceph_osdc_wait_request(osdc, req);
945 946
		if (ver)
			*ver = le64_to_cpu(req->r_reassert_version.version);
Y
Yehuda Sadeh 已提交
947 948
		dout("reassert_ver=%lld\n",
		     le64_to_cpu(req->r_reassert_version.version));
949 950 951 952 953 954 955 956
		ceph_osdc_put_request(req);
	}
	return ret;

done_err:
	bio_chain_put(req_data->bio);
	ceph_osdc_put_request(req);
done_pages:
Y
Yehuda Sadeh 已提交
957
	rbd_coll_end_req(req_data, ret, len);
958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991
	kfree(req_data);
	return ret;
}

/*
 * Ceph osd op callback
 */
static void rbd_req_cb(struct ceph_osd_request *req, struct ceph_msg *msg)
{
	struct rbd_request *req_data = req->r_priv;
	struct ceph_osd_reply_head *replyhead;
	struct ceph_osd_op *op;
	__s32 rc;
	u64 bytes;
	int read_op;

	/* parse reply */
	replyhead = msg->front.iov_base;
	WARN_ON(le32_to_cpu(replyhead->num_ops) == 0);
	op = (void *)(replyhead + 1);
	rc = le32_to_cpu(replyhead->result);
	bytes = le64_to_cpu(op->extent.length);
	read_op = (le32_to_cpu(op->op) == CEPH_OSD_OP_READ);

	dout("rbd_req_cb bytes=%lld readop=%d rc=%d\n", bytes, read_op, rc);

	if (rc == -ENOENT && read_op) {
		zero_bio_chain(req_data->bio, 0);
		rc = 0;
	} else if (rc == 0 && read_op && bytes < req_data->len) {
		zero_bio_chain(req_data->bio, bytes);
		bytes = req_data->len;
	}

Y
Yehuda Sadeh 已提交
992
	rbd_coll_end_req(req_data, rc, bytes);
993 994 995 996 997 998 999 1000

	if (req_data->bio)
		bio_chain_put(req_data->bio);

	ceph_osdc_put_request(req);
	kfree(req_data);
}

1001 1002 1003 1004 1005
static void rbd_simple_req_cb(struct ceph_osd_request *req, struct ceph_msg *msg)
{
	ceph_osdc_put_request(req);
}

1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017
/*
 * Do a synchronous ceph osd operation
 */
static int rbd_req_sync_op(struct rbd_device *dev,
			   struct ceph_snap_context *snapc,
			   u64 snapid,
			   int opcode,
			   int flags,
			   struct ceph_osd_req_op *orig_ops,
			   int num_reply,
			   const char *obj,
			   u64 ofs, u64 len,
1018 1019 1020
			   char *buf,
			   struct ceph_osd_request **linger_req,
			   u64 *ver)
1021 1022 1023 1024 1025 1026 1027 1028 1029
{
	int ret;
	struct page **pages;
	int num_pages;
	struct ceph_osd_req_op *ops = orig_ops;
	u32 payload_len;

	num_pages = calc_pages_for(ofs , len);
	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
D
Dan Carpenter 已提交
1030 1031
	if (IS_ERR(pages))
		return PTR_ERR(pages);
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051

	if (!orig_ops) {
		payload_len = (flags & CEPH_OSD_FLAG_WRITE ? len : 0);
		ret = rbd_create_rw_ops(&ops, 1, opcode, payload_len);
		if (ret < 0)
			goto done;

		if ((flags & CEPH_OSD_FLAG_WRITE) && buf) {
			ret = ceph_copy_to_page_vector(pages, buf, ofs, len);
			if (ret < 0)
				goto done_ops;
		}
	}

	ret = rbd_do_request(NULL, dev, snapc, snapid,
			  obj, ofs, len, NULL,
			  pages, num_pages,
			  flags,
			  ops,
			  2,
Y
Yehuda Sadeh 已提交
1052
			  NULL, 0,
1053 1054
			  NULL,
			  linger_req, ver);
1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077
	if (ret < 0)
		goto done_ops;

	if ((flags & CEPH_OSD_FLAG_READ) && buf)
		ret = ceph_copy_from_page_vector(pages, buf, ofs, ret);

done_ops:
	if (!orig_ops)
		rbd_destroy_ops(ops);
done:
	ceph_release_page_vector(pages, num_pages);
	return ret;
}

/*
 * Do an asynchronous ceph osd operation
 */
static int rbd_do_op(struct request *rq,
		     struct rbd_device *rbd_dev ,
		     struct ceph_snap_context *snapc,
		     u64 snapid,
		     int opcode, int flags, int num_reply,
		     u64 ofs, u64 len,
Y
Yehuda Sadeh 已提交
1078 1079 1080
		     struct bio *bio,
		     struct rbd_req_coll *coll,
		     int coll_index)
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
{
	char *seg_name;
	u64 seg_ofs;
	u64 seg_len;
	int ret;
	struct ceph_osd_req_op *ops;
	u32 payload_len;

	seg_name = kmalloc(RBD_MAX_SEG_NAME_LEN + 1, GFP_NOIO);
	if (!seg_name)
		return -ENOMEM;

	seg_len = rbd_get_segment(&rbd_dev->header,
				  rbd_dev->header.block_name,
				  ofs, len,
				  seg_name, &seg_ofs);

	payload_len = (flags & CEPH_OSD_FLAG_WRITE ? seg_len : 0);

	ret = rbd_create_rw_ops(&ops, 1, opcode, payload_len);
	if (ret < 0)
		goto done;

	/* we've taken care of segment sizes earlier when we
	   cloned the bios. We should never have a segment
	   truncated at this point */
	BUG_ON(seg_len < len);

	ret = rbd_do_request(rq, rbd_dev, snapc, snapid,
			     seg_name, seg_ofs, seg_len,
			     bio,
			     NULL, 0,
			     flags,
			     ops,
			     num_reply,
Y
Yehuda Sadeh 已提交
1116
			     coll, coll_index,
1117
			     rbd_req_cb, 0, NULL);
S
Sage Weil 已提交
1118 1119

	rbd_destroy_ops(ops);
1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131
done:
	kfree(seg_name);
	return ret;
}

/*
 * Request async osd write
 */
static int rbd_req_write(struct request *rq,
			 struct rbd_device *rbd_dev,
			 struct ceph_snap_context *snapc,
			 u64 ofs, u64 len,
Y
Yehuda Sadeh 已提交
1132 1133 1134
			 struct bio *bio,
			 struct rbd_req_coll *coll,
			 int coll_index)
1135 1136 1137 1138 1139
{
	return rbd_do_op(rq, rbd_dev, snapc, CEPH_NOSNAP,
			 CEPH_OSD_OP_WRITE,
			 CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
			 2,
Y
Yehuda Sadeh 已提交
1140
			 ofs, len, bio, coll, coll_index);
1141 1142 1143 1144 1145 1146 1147 1148 1149
}

/*
 * Request async osd read
 */
static int rbd_req_read(struct request *rq,
			 struct rbd_device *rbd_dev,
			 u64 snapid,
			 u64 ofs, u64 len,
Y
Yehuda Sadeh 已提交
1150 1151 1152
			 struct bio *bio,
			 struct rbd_req_coll *coll,
			 int coll_index)
1153 1154
{
	return rbd_do_op(rq, rbd_dev, NULL,
1155
			 snapid,
1156 1157 1158
			 CEPH_OSD_OP_READ,
			 CEPH_OSD_FLAG_READ,
			 2,
Y
Yehuda Sadeh 已提交
1159
			 ofs, len, bio, coll, coll_index);
1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
}

/*
 * Request sync osd read
 */
static int rbd_req_sync_read(struct rbd_device *dev,
			  struct ceph_snap_context *snapc,
			  u64 snapid,
			  const char *obj,
			  u64 ofs, u64 len,
1170 1171
			  char *buf,
			  u64 *ver)
1172 1173
{
	return rbd_req_sync_op(dev, NULL,
1174
			       snapid,
1175 1176 1177
			       CEPH_OSD_OP_READ,
			       CEPH_OSD_FLAG_READ,
			       NULL,
1178
			       1, obj, ofs, len, buf, NULL, ver);
1179 1180 1181
}

/*
1182 1183 1184 1185 1186 1187 1188 1189 1190
 * Request sync osd watch
 */
static int rbd_req_sync_notify_ack(struct rbd_device *dev,
				   u64 ver,
				   u64 notify_id,
				   const char *obj)
{
	struct ceph_osd_req_op *ops;
	struct page **pages = NULL;
S
Sage Weil 已提交
1191 1192 1193
	int ret;

	ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_NOTIFY_ACK, 0);
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206
	if (ret < 0)
		return ret;

	ops[0].watch.ver = cpu_to_le64(dev->header.obj_version);
	ops[0].watch.cookie = notify_id;
	ops[0].watch.flag = 0;

	ret = rbd_do_request(NULL, dev, NULL, CEPH_NOSNAP,
			  obj, 0, 0, NULL,
			  pages, 0,
			  CEPH_OSD_FLAG_READ,
			  ops,
			  1,
Y
Yehuda Sadeh 已提交
1207
			  NULL, 0,
1208 1209 1210 1211 1212 1213 1214 1215 1216
			  rbd_simple_req_cb, 0, NULL);

	rbd_destroy_ops(ops);
	return ret;
}

static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
{
	struct rbd_device *dev = (struct rbd_device *)data;
1217 1218
	int rc;

1219 1220 1221 1222 1223 1224
	if (!dev)
		return;

	dout("rbd_watch_cb %s notify_id=%lld opcode=%d\n", dev->obj_md_name,
		notify_id, (int)opcode);
	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
1225
	rc = __rbd_refresh_header(dev);
1226
	mutex_unlock(&ctl_mutex);
1227
	if (rc)
A
Alex Elder 已提交
1228 1229
		pr_warning(RBD_DRV_NAME "%d got notification but failed to "
			   " update snaps: %d\n", dev->major, rc);
1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241

	rbd_req_sync_notify_ack(dev, ver, notify_id, dev->obj_md_name);
}

/*
 * Request sync osd watch
 */
static int rbd_req_sync_watch(struct rbd_device *dev,
			      const char *obj,
			      u64 ver)
{
	struct ceph_osd_req_op *ops;
1242
	struct ceph_osd_client *osdc = &dev->rbd_client->client->osdc;
1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278

	int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_WATCH, 0);
	if (ret < 0)
		return ret;

	ret = ceph_osdc_create_event(osdc, rbd_watch_cb, 0,
				     (void *)dev, &dev->watch_event);
	if (ret < 0)
		goto fail;

	ops[0].watch.ver = cpu_to_le64(ver);
	ops[0].watch.cookie = cpu_to_le64(dev->watch_event->cookie);
	ops[0].watch.flag = 1;

	ret = rbd_req_sync_op(dev, NULL,
			      CEPH_NOSNAP,
			      0,
			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
			      ops,
			      1, obj, 0, 0, NULL,
			      &dev->watch_request, NULL);

	if (ret < 0)
		goto fail_event;

	rbd_destroy_ops(ops);
	return 0;

fail_event:
	ceph_osdc_cancel_event(dev->watch_event);
	dev->watch_event = NULL;
fail:
	rbd_destroy_ops(ops);
	return ret;
}

1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307
/*
 * Request sync osd unwatch
 */
static int rbd_req_sync_unwatch(struct rbd_device *dev,
				const char *obj)
{
	struct ceph_osd_req_op *ops;

	int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_WATCH, 0);
	if (ret < 0)
		return ret;

	ops[0].watch.ver = 0;
	ops[0].watch.cookie = cpu_to_le64(dev->watch_event->cookie);
	ops[0].watch.flag = 0;

	ret = rbd_req_sync_op(dev, NULL,
			      CEPH_NOSNAP,
			      0,
			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
			      ops,
			      1, obj, 0, 0, NULL, NULL, NULL);

	rbd_destroy_ops(ops);
	ceph_osdc_cancel_event(dev->watch_event);
	dev->watch_event = NULL;
	return ret;
}

1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
struct rbd_notify_info {
	struct rbd_device *dev;
};

static void rbd_notify_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
{
	struct rbd_device *dev = (struct rbd_device *)data;
	if (!dev)
		return;

	dout("rbd_notify_cb %s notify_id=%lld opcode=%d\n", dev->obj_md_name,
		notify_id, (int)opcode);
}

/*
 * Request sync osd notify
 */
static int rbd_req_sync_notify(struct rbd_device *dev,
		          const char *obj)
{
	struct ceph_osd_req_op *ops;
1329
	struct ceph_osd_client *osdc = &dev->rbd_client->client->osdc;
1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372
	struct ceph_osd_event *event;
	struct rbd_notify_info info;
	int payload_len = sizeof(u32) + sizeof(u32);
	int ret;

	ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_NOTIFY, payload_len);
	if (ret < 0)
		return ret;

	info.dev = dev;

	ret = ceph_osdc_create_event(osdc, rbd_notify_cb, 1,
				     (void *)&info, &event);
	if (ret < 0)
		goto fail;

	ops[0].watch.ver = 1;
	ops[0].watch.flag = 1;
	ops[0].watch.cookie = event->cookie;
	ops[0].watch.prot_ver = RADOS_NOTIFY_VER;
	ops[0].watch.timeout = 12;

	ret = rbd_req_sync_op(dev, NULL,
			       CEPH_NOSNAP,
			       0,
			       CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
			       ops,
			       1, obj, 0, 0, NULL, NULL, NULL);
	if (ret < 0)
		goto fail_event;

	ret = ceph_osdc_wait_event(event, CEPH_OSD_TIMEOUT_DEFAULT);
	dout("ceph_osdc_wait_event returned %d\n", ret);
	rbd_destroy_ops(ops);
	return 0;

fail_event:
	ceph_osdc_cancel_event(event);
fail:
	rbd_destroy_ops(ops);
	return ret;
}

1373 1374 1375 1376 1377 1378 1379 1380
/*
 * Request sync osd read
 */
static int rbd_req_sync_exec(struct rbd_device *dev,
			     const char *obj,
			     const char *cls,
			     const char *method,
			     const char *data,
1381 1382
			     int len,
			     u64 *ver)
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404
{
	struct ceph_osd_req_op *ops;
	int cls_len = strlen(cls);
	int method_len = strlen(method);
	int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_CALL,
				    cls_len + method_len + len);
	if (ret < 0)
		return ret;

	ops[0].cls.class_name = cls;
	ops[0].cls.class_len = (__u8)cls_len;
	ops[0].cls.method_name = method;
	ops[0].cls.method_len = (__u8)method_len;
	ops[0].cls.argc = 0;
	ops[0].cls.indata = data;
	ops[0].cls.indata_len = len;

	ret = rbd_req_sync_op(dev, NULL,
			       CEPH_NOSNAP,
			       0,
			       CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
			       ops,
1405
			       1, obj, 0, 0, NULL, NULL, ver);
1406 1407 1408 1409 1410 1411 1412

	rbd_destroy_ops(ops);

	dout("cls_exec returned %d\n", ret);
	return ret;
}

Y
Yehuda Sadeh 已提交
1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426
static struct rbd_req_coll *rbd_alloc_coll(int num_reqs)
{
	struct rbd_req_coll *coll =
			kzalloc(sizeof(struct rbd_req_coll) +
			        sizeof(struct rbd_req_status) * num_reqs,
				GFP_ATOMIC);

	if (!coll)
		return NULL;
	coll->total = num_reqs;
	kref_init(&coll->kref);
	return coll;
}

1427 1428 1429 1430 1431 1432 1433 1434 1435
/*
 * block device queue callback
 */
static void rbd_rq_fn(struct request_queue *q)
{
	struct rbd_device *rbd_dev = q->queuedata;
	struct request *rq;
	struct bio_pair *bp = NULL;

A
Alex Elder 已提交
1436
	while ((rq = blk_fetch_request(q))) {
1437 1438 1439 1440 1441
		struct bio *bio;
		struct bio *rq_bio, *next_bio = NULL;
		bool do_write;
		int size, op_size = 0;
		u64 ofs;
Y
Yehuda Sadeh 已提交
1442 1443
		int num_segs, cur_seg = 0;
		struct rbd_req_coll *coll;
1444 1445 1446 1447 1448 1449 1450 1451 1452 1453

		/* peek at request from block layer */
		if (!rq)
			break;

		dout("fetched request\n");

		/* filter out block requests we don't understand */
		if ((rq->cmd_type != REQ_TYPE_FS)) {
			__blk_end_request_all(rq, 0);
A
Alex Elder 已提交
1454
			continue;
1455 1456 1457 1458 1459 1460
		}

		/* deduce our operation (read, write) */
		do_write = (rq_data_dir(rq) == WRITE);

		size = blk_rq_bytes(rq);
A
Alex Elder 已提交
1461
		ofs = blk_rq_pos(rq) * SECTOR_SIZE;
1462 1463 1464
		rq_bio = rq->bio;
		if (do_write && rbd_dev->read_only) {
			__blk_end_request_all(rq, -EROFS);
A
Alex Elder 已提交
1465
			continue;
1466 1467 1468 1469 1470 1471
		}

		spin_unlock_irq(q->queue_lock);

		dout("%s 0x%x bytes at 0x%llx\n",
		     do_write ? "write" : "read",
A
Alex Elder 已提交
1472
		     size, blk_rq_pos(rq) * SECTOR_SIZE);
1473

Y
Yehuda Sadeh 已提交
1474 1475 1476 1477 1478
		num_segs = rbd_get_num_segments(&rbd_dev->header, ofs, size);
		coll = rbd_alloc_coll(num_segs);
		if (!coll) {
			spin_lock_irq(q->queue_lock);
			__blk_end_request_all(rq, -ENOMEM);
A
Alex Elder 已提交
1479
			continue;
Y
Yehuda Sadeh 已提交
1480 1481
		}

1482 1483 1484 1485 1486 1487 1488
		do {
			/* a bio clone to be passed down to OSD req */
			dout("rq->bio->bi_vcnt=%d\n", rq->bio->bi_vcnt);
			op_size = rbd_get_segment(&rbd_dev->header,
						  rbd_dev->header.block_name,
						  ofs, size,
						  NULL, NULL);
Y
Yehuda Sadeh 已提交
1489
			kref_get(&coll->kref);
1490 1491 1492
			bio = bio_chain_clone(&rq_bio, &next_bio, &bp,
					      op_size, GFP_ATOMIC);
			if (!bio) {
Y
Yehuda Sadeh 已提交
1493 1494 1495
				rbd_coll_end_req_index(rq, coll, cur_seg,
						       -ENOMEM, op_size);
				goto next_seg;
1496 1497
			}

Y
Yehuda Sadeh 已提交
1498

1499 1500 1501 1502 1503
			/* init OSD command: write or read */
			if (do_write)
				rbd_req_write(rq, rbd_dev,
					      rbd_dev->header.snapc,
					      ofs,
Y
Yehuda Sadeh 已提交
1504 1505
					      op_size, bio,
					      coll, cur_seg);
1506 1507
			else
				rbd_req_read(rq, rbd_dev,
1508
					     rbd_dev->snap_id,
1509
					     ofs,
Y
Yehuda Sadeh 已提交
1510 1511
					     op_size, bio,
					     coll, cur_seg);
1512

Y
Yehuda Sadeh 已提交
1513
next_seg:
1514 1515 1516
			size -= op_size;
			ofs += op_size;

Y
Yehuda Sadeh 已提交
1517
			cur_seg++;
1518 1519
			rq_bio = next_bio;
		} while (size > 0);
Y
Yehuda Sadeh 已提交
1520
		kref_put(&coll->kref, rbd_coll_release);
1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536

		if (bp)
			bio_pair_release(bp);
		spin_lock_irq(q->queue_lock);
	}
}

/*
 * 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,
 * which we handle later at bio_chain_clone
 */
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
1537 1538 1539
	unsigned int chunk_sectors;
	sector_t sector;
	unsigned int bio_sectors;
1540 1541
	int max;

A
Alex Elder 已提交
1542 1543 1544 1545
	chunk_sectors = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
	sector = bmd->bi_sector + get_start_sect(bmd->bi_bdev);
	bio_sectors = bmd->bi_size >> SECTOR_SHIFT;

1546
	max =  (chunk_sectors - ((sector & (chunk_sectors - 1))
A
Alex Elder 已提交
1547
				 + bio_sectors)) << SECTOR_SHIFT;
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578
	if (max < 0)
		max = 0; /* bio_add cannot handle a negative return */
	if (max <= bvec->bv_len && bio_sectors == 0)
		return bvec->bv_len;
	return max;
}

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

	if (!disk)
		return;

	rbd_header_free(&rbd_dev->header);

	if (disk->flags & GENHD_FL_UP)
		del_gendisk(disk);
	if (disk->queue)
		blk_cleanup_queue(disk->queue);
	put_disk(disk);
}

/*
 * reload the ondisk the header 
 */
static int rbd_read_header(struct rbd_device *rbd_dev,
			   struct rbd_image_header *header)
{
	ssize_t rc;
	struct rbd_image_header_ondisk *dh;
1579
	u32 snap_count = 0;
1580
	u64 ver;
A
Alex Elder 已提交
1581
	size_t len;
1582

A
Alex Elder 已提交
1583 1584 1585 1586 1587 1588
	/*
	 * First reads the fixed-size header to determine the number
	 * of snapshots, then re-reads it, along with all snapshot
	 * records as well as their stored names.
	 */
	len = sizeof (*dh);
1589 1590 1591 1592 1593 1594 1595 1596 1597
	while (1) {
		dh = kmalloc(len, GFP_KERNEL);
		if (!dh)
			return -ENOMEM;

		rc = rbd_req_sync_read(rbd_dev,
				       NULL, CEPH_NOSNAP,
				       rbd_dev->obj_md_name,
				       0, len,
1598
				       (char *)dh, &ver);
1599 1600 1601 1602
		if (rc < 0)
			goto out_dh;

		rc = rbd_header_from_disk(header, dh, snap_count, GFP_KERNEL);
1603
		if (rc < 0) {
A
Alex Elder 已提交
1604
			if (rc == -ENXIO)
1605 1606
				pr_warning("unrecognized header format"
					   " for image %s", rbd_dev->obj);
1607
			goto out_dh;
1608
		}
1609

A
Alex Elder 已提交
1610 1611 1612 1613 1614 1615 1616 1617 1618 1619
		if (snap_count == header->total_snaps)
			break;

		snap_count = header->total_snaps;
		len = sizeof (*dh) +
			snap_count * sizeof(struct rbd_image_snap_ondisk) +
			header->snap_names_len;

		rbd_header_free(header);
		kfree(dh);
1620
	}
1621
	header->obj_version = ver;
1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637

out_dh:
	kfree(dh);
	return rc;
}

/*
 * create a snapshot
 */
static int rbd_header_add_snap(struct rbd_device *dev,
			       const char *snap_name,
			       gfp_t gfp_flags)
{
	int name_len = strlen(snap_name);
	u64 new_snapid;
	int ret;
1638
	void *data, *p, *e;
1639
	u64 ver;
1640
	struct ceph_mon_client *monc;
1641 1642

	/* we should create a snapshot only if we're pointing at the head */
1643
	if (dev->snap_id != CEPH_NOSNAP)
1644 1645
		return -EINVAL;

1646 1647
	monc = &dev->rbd_client->client->monc;
	ret = ceph_monc_create_snapid(monc, dev->poolid, &new_snapid);
1648 1649 1650 1651 1652 1653 1654 1655
	dout("created snapid=%lld\n", new_snapid);
	if (ret < 0)
		return ret;

	data = kmalloc(name_len + 16, gfp_flags);
	if (!data)
		return -ENOMEM;

1656 1657
	p = data;
	e = data + name_len + 16;
1658

1659 1660
	ceph_encode_string_safe(&p, e, snap_name, name_len, bad);
	ceph_encode_64_safe(&p, e, new_snapid, bad);
1661 1662

	ret = rbd_req_sync_exec(dev, dev->obj_md_name, "rbd", "snap_add",
1663
				data, p - data, &ver);
1664

1665
	kfree(data);
1666 1667 1668 1669

	if (ret < 0)
		return ret;

1670 1671 1672
	down_write(&dev->header_rwsem);
	dev->header.snapc->seq = new_snapid;
	up_write(&dev->header_rwsem);
1673 1674 1675 1676 1677 1678

	return 0;
bad:
	return -ERANGE;
}

1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
static void __rbd_remove_all_snaps(struct rbd_device *rbd_dev)
{
	struct rbd_snap *snap;

	while (!list_empty(&rbd_dev->snaps)) {
		snap = list_first_entry(&rbd_dev->snaps, struct rbd_snap, node);
		__rbd_remove_snap_dev(rbd_dev, snap);
	}
}

1689 1690 1691
/*
 * only read the first part of the ondisk header, without the snaps info
 */
1692
static int __rbd_refresh_header(struct rbd_device *rbd_dev)
1693 1694 1695 1696
{
	int ret;
	struct rbd_image_header h;
	u64 snap_seq;
1697
	int follow_seq = 0;
1698 1699 1700 1701 1702

	ret = rbd_read_header(rbd_dev, &h);
	if (ret < 0)
		return ret;

1703
	/* resized? */
A
Alex Elder 已提交
1704
	set_capacity(rbd_dev->disk, h.image_size / SECTOR_SIZE);
1705

1706
	down_write(&rbd_dev->header_rwsem);
1707 1708

	snap_seq = rbd_dev->header.snapc->seq;
1709 1710 1711 1712 1713
	if (rbd_dev->header.total_snaps &&
	    rbd_dev->header.snapc->snaps[0] == snap_seq)
		/* pointing at the head, will need to follow that
		   if head moves */
		follow_seq = 1;
1714 1715 1716 1717 1718 1719 1720 1721

	kfree(rbd_dev->header.snapc);
	kfree(rbd_dev->header.snap_names);
	kfree(rbd_dev->header.snap_sizes);

	rbd_dev->header.total_snaps = h.total_snaps;
	rbd_dev->header.snapc = h.snapc;
	rbd_dev->header.snap_names = h.snap_names;
1722
	rbd_dev->header.snap_names_len = h.snap_names_len;
1723
	rbd_dev->header.snap_sizes = h.snap_sizes;
1724 1725 1726 1727
	if (follow_seq)
		rbd_dev->header.snapc->seq = rbd_dev->header.snapc->snaps[0];
	else
		rbd_dev->header.snapc->seq = snap_seq;
1728

1729 1730
	ret = __rbd_init_snaps_header(rbd_dev);

1731
	up_write(&rbd_dev->header_rwsem);
1732

1733
	return ret;
1734 1735 1736 1737 1738 1739 1740
}

static int rbd_init_disk(struct rbd_device *rbd_dev)
{
	struct gendisk *disk;
	struct request_queue *q;
	int rc;
A
Alex Elder 已提交
1741
	u64 segment_size;
1742 1743 1744 1745 1746 1747 1748
	u64 total_size = 0;

	/* contact OSD, request size info about the object being mapped */
	rc = rbd_read_header(rbd_dev, &rbd_dev->header);
	if (rc)
		return rc;

1749 1750 1751 1752 1753
	/* no need to lock here, as rbd_dev is not registered yet */
	rc = __rbd_init_snaps_header(rbd_dev);
	if (rc)
		return rc;

1754
	rc = rbd_header_set_snap(rbd_dev, &total_size);
1755 1756 1757 1758 1759 1760 1761 1762 1763
	if (rc)
		return rc;

	/* create gendisk info */
	rc = -ENOMEM;
	disk = alloc_disk(RBD_MINORS_PER_MAJOR);
	if (!disk)
		goto out;

A
Alex Elder 已提交
1764
	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
1765
		 rbd_dev->id);
1766 1767 1768 1769 1770 1771 1772 1773 1774 1775
	disk->major = rbd_dev->major;
	disk->first_minor = 0;
	disk->fops = &rbd_bd_ops;
	disk->private_data = rbd_dev;

	/* init rq */
	rc = -ENOMEM;
	q = blk_init_queue(rbd_rq_fn, &rbd_dev->lock);
	if (!q)
		goto out_disk;
1776

A
Alex Elder 已提交
1777 1778 1779
	/* We use the default size, but let's be explicit about it. */
	blk_queue_physical_block_size(q, SECTOR_SIZE);

1780
	/* set io sizes to object size */
A
Alex Elder 已提交
1781 1782 1783 1784 1785
	segment_size = rbd_obj_bytes(&rbd_dev->header);
	blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
	blk_queue_max_segment_size(q, segment_size);
	blk_queue_io_min(q, segment_size);
	blk_queue_io_opt(q, segment_size);
1786

1787 1788 1789 1790 1791 1792 1793 1794 1795
	blk_queue_merge_bvec(q, rbd_merge_bvec);
	disk->queue = q;

	q->queuedata = rbd_dev;

	rbd_dev->disk = disk;
	rbd_dev->q = q;

	/* finally, announce the disk to the world */
A
Alex Elder 已提交
1796
	set_capacity(disk, total_size / SECTOR_SIZE);
1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
	add_disk(disk);

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

out_disk:
	put_disk(disk);
out:
	return rc;
}

1809 1810 1811 1812
/*
  sysfs
*/

A
Alex Elder 已提交
1813 1814 1815 1816 1817
static struct rbd_device *dev_to_rbd_dev(struct device *dev)
{
	return container_of(dev, struct rbd_device, dev);
}

1818 1819 1820
static ssize_t rbd_size_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
1821
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1822 1823 1824 1825 1826 1827 1828

	return sprintf(buf, "%llu\n", (unsigned long long)rbd_dev->header.image_size);
}

static ssize_t rbd_major_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
1829
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1830

1831 1832 1833 1834 1835
	return sprintf(buf, "%d\n", rbd_dev->major);
}

static ssize_t rbd_client_id_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
1836
{
A
Alex Elder 已提交
1837
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1838

1839 1840
	return sprintf(buf, "client%lld\n",
			ceph_client_id(rbd_dev->rbd_client->client));
1841 1842
}

1843 1844
static ssize_t rbd_pool_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
1845
{
A
Alex Elder 已提交
1846
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1847 1848 1849 1850 1851 1852 1853

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

static ssize_t rbd_name_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
A
Alex Elder 已提交
1854
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1855 1856 1857 1858 1859 1860 1861 1862

	return sprintf(buf, "%s\n", rbd_dev->obj);
}

static ssize_t rbd_snap_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
A
Alex Elder 已提交
1863
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1864 1865 1866 1867 1868 1869 1870 1871 1872

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

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
1873
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
1874 1875
	int rc;
	int ret = size;
1876 1877 1878

	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);

1879
	rc = __rbd_refresh_header(rbd_dev);
1880 1881
	if (rc < 0)
		ret = rc;
1882

1883 1884 1885
	mutex_unlock(&ctl_mutex);
	return ret;
}
1886

1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
static DEVICE_ATTR(create_snap, S_IWUSR, NULL, rbd_snap_add);

static struct attribute *rbd_attrs[] = {
	&dev_attr_size.attr,
	&dev_attr_major.attr,
	&dev_attr_client_id.attr,
	&dev_attr_pool.attr,
	&dev_attr_name.attr,
	&dev_attr_current_snap.attr,
	&dev_attr_refresh.attr,
	&dev_attr_create_snap.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,
};


/*
  sysfs - snapshots
*/

static ssize_t rbd_snap_size_show(struct device *dev,
				  struct device_attribute *attr,
				  char *buf)
{
	struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);

J
Josh Durgin 已提交
1938
	return sprintf(buf, "%llu\n", (unsigned long long)snap->size);
1939 1940 1941 1942 1943 1944 1945 1946
}

static ssize_t rbd_snap_id_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);

J
Josh Durgin 已提交
1947
	return sprintf(buf, "%llu\n", (unsigned long long)snap->id);
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120
}

static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL);
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);

static struct attribute *rbd_snap_attrs[] = {
	&dev_attr_snap_size.attr,
	&dev_attr_snap_id.attr,
	NULL,
};

static struct attribute_group rbd_snap_attr_group = {
	.attrs = rbd_snap_attrs,
};

static void rbd_snap_dev_release(struct device *dev)
{
	struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
	kfree(snap->name);
	kfree(snap);
}

static const struct attribute_group *rbd_snap_attr_groups[] = {
	&rbd_snap_attr_group,
	NULL
};

static struct device_type rbd_snap_device_type = {
	.groups		= rbd_snap_attr_groups,
	.release	= rbd_snap_dev_release,
};

static void __rbd_remove_snap_dev(struct rbd_device *rbd_dev,
				  struct rbd_snap *snap)
{
	list_del(&snap->node);
	device_unregister(&snap->dev);
}

static int rbd_register_snap_dev(struct rbd_device *rbd_dev,
				  struct rbd_snap *snap,
				  struct device *parent)
{
	struct device *dev = &snap->dev;
	int ret;

	dev->type = &rbd_snap_device_type;
	dev->parent = parent;
	dev->release = rbd_snap_dev_release;
	dev_set_name(dev, "snap_%s", snap->name);
	ret = device_register(dev);

	return ret;
}

static int __rbd_add_snap_dev(struct rbd_device *rbd_dev,
			      int i, const char *name,
			      struct rbd_snap **snapp)
{
	int ret;
	struct rbd_snap *snap = kzalloc(sizeof(*snap), GFP_KERNEL);
	if (!snap)
		return -ENOMEM;
	snap->name = kstrdup(name, GFP_KERNEL);
	snap->size = rbd_dev->header.snap_sizes[i];
	snap->id = rbd_dev->header.snapc->snaps[i];
	if (device_is_registered(&rbd_dev->dev)) {
		ret = rbd_register_snap_dev(rbd_dev, snap,
					     &rbd_dev->dev);
		if (ret < 0)
			goto err;
	}
	*snapp = snap;
	return 0;
err:
	kfree(snap->name);
	kfree(snap);
	return ret;
}

/*
 * search for the previous snap in a null delimited string list
 */
const char *rbd_prev_snap_name(const char *name, const char *start)
{
	if (name < start + 2)
		return NULL;

	name -= 2;
	while (*name) {
		if (name == start)
			return start;
		name--;
	}
	return name + 1;
}

/*
 * compare the old list of snapshots that we have to what's in the header
 * and update it accordingly. Note that the header holds the snapshots
 * in a reverse order (from newest to oldest) and we need to go from
 * older to new so that we don't get a duplicate snap name when
 * doing the process (e.g., removed snapshot and recreated a new
 * one with the same name.
 */
static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
{
	const char *name, *first_name;
	int i = rbd_dev->header.total_snaps;
	struct rbd_snap *snap, *old_snap = NULL;
	int ret;
	struct list_head *p, *n;

	first_name = rbd_dev->header.snap_names;
	name = first_name + rbd_dev->header.snap_names_len;

	list_for_each_prev_safe(p, n, &rbd_dev->snaps) {
		u64 cur_id;

		old_snap = list_entry(p, struct rbd_snap, node);

		if (i)
			cur_id = rbd_dev->header.snapc->snaps[i - 1];

		if (!i || old_snap->id < cur_id) {
			/* old_snap->id was skipped, thus was removed */
			__rbd_remove_snap_dev(rbd_dev, old_snap);
			continue;
		}
		if (old_snap->id == cur_id) {
			/* we have this snapshot already */
			i--;
			name = rbd_prev_snap_name(name, first_name);
			continue;
		}
		for (; i > 0;
		     i--, name = rbd_prev_snap_name(name, first_name)) {
			if (!name) {
				WARN_ON(1);
				return -EINVAL;
			}
			cur_id = rbd_dev->header.snapc->snaps[i];
			/* snapshot removal? handle it above */
			if (cur_id >= old_snap->id)
				break;
			/* a new snapshot */
			ret = __rbd_add_snap_dev(rbd_dev, i - 1, name, &snap);
			if (ret < 0)
				return ret;

			/* note that we add it backward so using n and not p */
			list_add(&snap->node, n);
			p = &snap->node;
		}
	}
	/* we're done going over the old snap list, just add what's left */
	for (; i > 0; i--) {
		name = rbd_prev_snap_name(name, first_name);
		if (!name) {
			WARN_ON(1);
			return -EINVAL;
		}
		ret = __rbd_add_snap_dev(rbd_dev, i - 1, name, &snap);
		if (ret < 0)
			return ret;
		list_add(&snap->node, &rbd_dev->snaps);
	}

	return 0;
}

static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
{
A
Alex Elder 已提交
2121
	int ret;
2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134
	struct device *dev;
	struct rbd_snap *snap;

	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
	dev = &rbd_dev->dev;

	dev->bus = &rbd_bus_type;
	dev->type = &rbd_device_type;
	dev->parent = &rbd_root_dev;
	dev->release = rbd_dev_release;
	dev_set_name(dev, "%d", rbd_dev->id);
	ret = device_register(dev);
	if (ret < 0)
A
Alex Elder 已提交
2135
		goto out;
2136 2137 2138 2139 2140

	list_for_each_entry(snap, &rbd_dev->snaps, node) {
		ret = rbd_register_snap_dev(rbd_dev, snap,
					     &rbd_dev->dev);
		if (ret < 0)
2141 2142
			break;
	}
A
Alex Elder 已提交
2143
out:
2144 2145
	mutex_unlock(&ctl_mutex);
	return ret;
2146 2147
}

2148 2149 2150 2151 2152
static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
{
	device_unregister(&rbd_dev->dev);
}

2153 2154 2155 2156 2157 2158 2159 2160 2161
static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
{
	int ret, rc;

	do {
		ret = rbd_req_sync_watch(rbd_dev, rbd_dev->obj_md_name,
					 rbd_dev->header.obj_version);
		if (ret == -ERANGE) {
			mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2162
			rc = __rbd_refresh_header(rbd_dev);
2163 2164 2165 2166 2167 2168 2169 2170 2171
			mutex_unlock(&ctl_mutex);
			if (rc < 0)
				return rc;
		}
	} while (ret == -ERANGE);

	return ret;
}

2172 2173 2174
static atomic64_t rbd_id_max = ATOMIC64_INIT(0);

/*
2175 2176
 * Get a unique rbd identifier for the given new rbd_dev, and add
 * the rbd_dev to the global list.  The minimum rbd id is 1.
2177
 */
2178
static void rbd_id_get(struct rbd_device *rbd_dev)
2179
{
2180 2181 2182 2183 2184
	rbd_dev->id = atomic64_inc_return(&rbd_id_max);

	spin_lock(&rbd_dev_list_lock);
	list_add_tail(&rbd_dev->node, &rbd_dev_list);
	spin_unlock(&rbd_dev_list_lock);
2185
}
2186

2187
/*
2188 2189
 * Remove an rbd_dev from the global list, and record that its
 * identifier is no longer in use.
2190
 */
2191
static void rbd_id_put(struct rbd_device *rbd_dev)
2192
{
2193 2194 2195 2196 2197
	struct list_head *tmp;
	int rbd_id = rbd_dev->id;
	int max_id;

	BUG_ON(rbd_id < 1);
2198 2199 2200

	spin_lock(&rbd_dev_list_lock);
	list_del_init(&rbd_dev->node);
2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223

	/*
	 * If the id being "put" is not the current maximum, there
	 * is nothing special we need to do.
	 */
	if (rbd_id != atomic64_read(&rbd_id_max)) {
		spin_unlock(&rbd_dev_list_lock);
		return;
	}

	/*
	 * We need to update the current maximum id.  Search the
	 * list to find out what it is.  We're more likely to find
	 * the maximum at the end, so search the list backward.
	 */
	max_id = 0;
	list_for_each_prev(tmp, &rbd_dev_list) {
		struct rbd_device *rbd_dev;

		rbd_dev = list_entry(tmp, struct rbd_device, node);
		if (rbd_id > max_id)
			max_id = rbd_id;
	}
2224
	spin_unlock(&rbd_dev_list_lock);
2225

2226
	/*
2227 2228 2229 2230
	 * The max id could have been updated by rbd_id_get(), in
	 * which case it now accurately reflects the new maximum.
	 * Be careful not to overwrite the maximum value in that
	 * case.
2231
	 */
2232
	atomic64_cmpxchg(&rbd_id_max, rbd_id, max_id);
2233 2234
}

2235 2236 2237
/*
 * 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
2238 2239
 * the token (string of non-white space characters) found.  Note
 * that *buf must be terminated with '\0'.
2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256
 */
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 */
}

/*
 * Finds the next token in *buf, and if the provided token buffer is
 * big enough, copies the found token into it.  The result, if
A
Alex Elder 已提交
2257 2258
 * copied, is guaranteed to be terminated with '\0'.  Note that *buf
 * must be terminated with '\0' on entry.
2259 2260 2261 2262 2263
 *
 * Returns the length of the token found (not including the '\0').
 * Return value will be 0 if no token is found, and it will be >=
 * token_size if the token would not fit.
 *
A
Alex Elder 已提交
2264
 * The *buf pointer will be updated to point beyond the end of the
2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283
 * found token.  Note that this occurs even if the token buffer is
 * too small to hold it.
 */
static inline size_t copy_token(const char **buf,
				char *token,
				size_t token_size)
{
        size_t len;

	len = next_token(buf);
	if (len < token_size) {
		memcpy(token, *buf, len);
		*(token + len) = '\0';
	}
	*buf += len;

        return len;
}

2284 2285 2286 2287 2288 2289 2290 2291
/*
 * This fills in the pool_name, obj, obj_len, snap_name, obj_len,
 * rbd_dev, rbd_md_name, and name fields of the given rbd_dev, based
 * on the list of monitor addresses and other options provided via
 * /sys/bus/rbd/add.
 */
static int rbd_add_parse_args(struct rbd_device *rbd_dev,
			      const char *buf,
2292
			      const char **mon_addrs,
2293
			      size_t *mon_addrs_size,
2294 2295 2296 2297 2298 2299 2300
			      char *options,
			      size_t options_size)
{
	size_t	len;

	/* The first four tokens are required */

2301 2302
	len = next_token(&buf);
	if (!len)
2303
		return -EINVAL;
2304
	*mon_addrs_size = len + 1;
2305 2306 2307
	*mon_addrs = buf;

	buf += len;
2308

2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323
	len = copy_token(&buf, options, options_size);
	if (!len || len >= options_size)
		return -EINVAL;

	len = copy_token(&buf, rbd_dev->pool_name, sizeof (rbd_dev->pool_name));
	if (!len || len >= sizeof (rbd_dev->pool_name))
		return -EINVAL;

	len = copy_token(&buf, rbd_dev->obj, sizeof (rbd_dev->obj));
	if (!len || len >= sizeof (rbd_dev->obj))
		return -EINVAL;

	/* We have the object length in hand, save it. */

	rbd_dev->obj_len = len;
2324

A
Alex Elder 已提交
2325 2326 2327
	BUILD_BUG_ON(RBD_MAX_MD_NAME_LEN
				< RBD_MAX_OBJ_NAME_LEN + sizeof (RBD_SUFFIX));
	sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX);
2328

2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339
	/*
	 * The snapshot name is optional, but it's an error if it's
	 * too long.  If no snapshot is supplied, fill in the default.
	 */
	len = copy_token(&buf, rbd_dev->snap_name, sizeof (rbd_dev->snap_name));
	if (!len)
		memcpy(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME,
			sizeof (RBD_SNAP_HEAD_NAME));
	else if (len >= sizeof (rbd_dev->snap_name))
		return -EINVAL;

2340 2341 2342
	return 0;
}

2343 2344 2345
static ssize_t rbd_add(struct bus_type *bus,
		       const char *buf,
		       size_t count)
2346 2347
{
	struct rbd_device *rbd_dev;
2348 2349
	const char *mon_addrs = NULL;
	size_t mon_addrs_size = 0;
2350 2351 2352
	char *options = NULL;
	struct ceph_osd_client *osdc;
	int rc = -ENOMEM;
2353 2354 2355 2356

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

2357 2358 2359
	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
	if (!rbd_dev)
		goto err_nomem;
2360
	options = kmalloc(count, GFP_KERNEL);
2361
	if (!options)
2362
		goto err_nomem;
2363 2364 2365 2366

	/* static rbd_device initialization */
	spin_lock_init(&rbd_dev->lock);
	INIT_LIST_HEAD(&rbd_dev->node);
2367
	INIT_LIST_HEAD(&rbd_dev->snaps);
2368
	init_rwsem(&rbd_dev->header_rwsem);
2369

2370
	init_rwsem(&rbd_dev->header_rwsem);
2371

2372
	/* generate unique id: find highest unique id, add one */
2373
	rbd_id_get(rbd_dev);
2374

2375
	/* Fill in the device name, now that we have its id. */
A
Alex Elder 已提交
2376 2377 2378
	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->id);
2379

2380
	/* parse add command */
2381
	rc = rbd_add_parse_args(rbd_dev, buf, &mon_addrs, &mon_addrs_size,
2382
				options, count);
2383
	if (rc)
A
Alex Elder 已提交
2384
		goto err_put_id;
2385

2386 2387
	rbd_dev->rbd_client = rbd_get_client(mon_addrs, mon_addrs_size - 1,
						options);
2388 2389
	if (IS_ERR(rbd_dev->rbd_client)) {
		rc = PTR_ERR(rbd_dev->rbd_client);
A
Alex Elder 已提交
2390
		goto err_put_id;
2391
	}
2392 2393

	/* pick the pool */
2394
	osdc = &rbd_dev->rbd_client->client->osdc;
2395 2396 2397 2398 2399 2400
	rc = ceph_pg_poolid_by_name(osdc->osdmap, rbd_dev->pool_name);
	if (rc < 0)
		goto err_out_client;
	rbd_dev->poolid = rc;

	/* register our block device */
2401 2402
	rc = register_blkdev(0, rbd_dev->name);
	if (rc < 0)
2403
		goto err_out_client;
2404
	rbd_dev->major = rc;
2405

2406 2407
	rc = rbd_bus_add_dev(rbd_dev);
	if (rc)
2408 2409
		goto err_out_blkdev;

2410 2411 2412 2413 2414 2415
	/*
	 * At this point cleanup in the event of an error is the job
	 * of the sysfs code (initiated by rbd_bus_del_dev()).
	 *
	 * Set up and announce blkdev mapping.
	 */
2416 2417
	rc = rbd_init_disk(rbd_dev);
	if (rc)
2418
		goto err_out_bus;
2419

2420 2421 2422 2423
	rc = rbd_init_watch_dev(rbd_dev);
	if (rc)
		goto err_out_bus;

2424 2425
	return count;

2426 2427 2428 2429 2430 2431 2432
err_out_bus:
	/* this will also clean up rest of rbd_dev stuff */

	rbd_bus_del_dev(rbd_dev);
	kfree(options);
	return rc;

2433 2434 2435 2436
err_out_blkdev:
	unregister_blkdev(rbd_dev->major, rbd_dev->name);
err_out_client:
	rbd_put_client(rbd_dev);
A
Alex Elder 已提交
2437
err_put_id:
2438
	rbd_id_put(rbd_dev);
2439
err_nomem:
2440
	kfree(options);
2441 2442
	kfree(rbd_dev);

2443 2444
	dout("Error adding device %s\n", buf);
	module_put(THIS_MODULE);
2445 2446

	return (ssize_t) rc;
2447 2448 2449 2450 2451 2452 2453
}

static struct rbd_device *__rbd_get_dev(unsigned long id)
{
	struct list_head *tmp;
	struct rbd_device *rbd_dev;

2454
	spin_lock(&rbd_dev_list_lock);
2455 2456
	list_for_each(tmp, &rbd_dev_list) {
		rbd_dev = list_entry(tmp, struct rbd_device, node);
2457 2458
		if (rbd_dev->id == id) {
			spin_unlock(&rbd_dev_list_lock);
2459
			return rbd_dev;
2460
		}
2461
	}
2462
	spin_unlock(&rbd_dev_list_lock);
2463 2464 2465
	return NULL;
}

2466
static void rbd_dev_release(struct device *dev)
2467
{
A
Alex Elder 已提交
2468
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2469

2470 2471 2472 2473
	if (rbd_dev->watch_request) {
		struct ceph_client *client = rbd_dev->rbd_client->client;

		ceph_osdc_unregister_linger_request(&client->osdc,
2474
						    rbd_dev->watch_request);
2475
	}
2476
	if (rbd_dev->watch_event)
2477
		rbd_req_sync_unwatch(rbd_dev, rbd_dev->obj_md_name);
2478

2479 2480 2481 2482 2483
	rbd_put_client(rbd_dev);

	/* clean up and free blkdev */
	rbd_free_disk(rbd_dev);
	unregister_blkdev(rbd_dev->major, rbd_dev->name);
2484 2485 2486

	/* done with the id, and with the rbd_dev */
	rbd_id_put(rbd_dev);
2487 2488 2489 2490 2491 2492
	kfree(rbd_dev);

	/* release module ref */
	module_put(THIS_MODULE);
}

2493 2494 2495
static ssize_t rbd_remove(struct bus_type *bus,
			  const char *buf,
			  size_t count)
2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518
{
	struct rbd_device *rbd_dev = NULL;
	int target_id, rc;
	unsigned long ul;
	int ret = count;

	rc = strict_strtoul(buf, 10, &ul);
	if (rc)
		return rc;

	/* convert to int; abort if we lost anything in the conversion */
	target_id = (int) ul;
	if (target_id != ul)
		return -EINVAL;

	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);

	rbd_dev = __rbd_get_dev(target_id);
	if (!rbd_dev) {
		ret = -ENOENT;
		goto done;
	}

2519 2520
	__rbd_remove_all_snaps(rbd_dev);
	rbd_bus_del_dev(rbd_dev);
2521 2522 2523 2524 2525 2526

done:
	mutex_unlock(&ctl_mutex);
	return ret;
}

2527 2528 2529 2530
static ssize_t rbd_snap_add(struct device *dev,
			    struct device_attribute *attr,
			    const char *buf,
			    size_t count)
2531
{
A
Alex Elder 已提交
2532
	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2533 2534
	int ret;
	char *name = kmalloc(count + 1, GFP_KERNEL);
2535 2536 2537
	if (!name)
		return -ENOMEM;

2538
	snprintf(name, count, "%s", buf);
2539 2540 2541 2542 2543 2544

	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);

	ret = rbd_header_add_snap(rbd_dev,
				  name, GFP_KERNEL);
	if (ret < 0)
2545
		goto err_unlock;
2546

2547
	ret = __rbd_refresh_header(rbd_dev);
2548
	if (ret < 0)
2549 2550 2551 2552 2553 2554 2555 2556
		goto err_unlock;

	/* shouldn't hold ctl_mutex when notifying.. notify might
	   trigger a watch callback that would need to get that mutex */
	mutex_unlock(&ctl_mutex);

	/* make a best effort, don't error if failed */
	rbd_req_sync_notify(rbd_dev, rbd_dev->obj_md_name);
2557 2558

	ret = count;
2559 2560 2561 2562
	kfree(name);
	return ret;

err_unlock:
2563 2564 2565 2566 2567 2568 2569
	mutex_unlock(&ctl_mutex);
	kfree(name);
	return ret;
}

/*
 * create control files in sysfs
2570
 * /sys/bus/rbd/...
2571 2572 2573
 */
static int rbd_sysfs_init(void)
{
2574
	int ret;
2575

2576
	ret = device_register(&rbd_root_dev);
A
Alex Elder 已提交
2577
	if (ret < 0)
2578
		return ret;
2579

2580 2581 2582
	ret = bus_register(&rbd_bus_type);
	if (ret < 0)
		device_unregister(&rbd_root_dev);
2583 2584 2585 2586 2587 2588

	return ret;
}

static void rbd_sysfs_cleanup(void)
{
2589
	bus_unregister(&rbd_bus_type);
2590
	device_unregister(&rbd_root_dev);
2591 2592 2593 2594 2595 2596 2597 2598 2599
}

int __init rbd_init(void)
{
	int rc;

	rc = rbd_sysfs_init();
	if (rc)
		return rc;
A
Alex Elder 已提交
2600
	pr_info("loaded " RBD_DRV_NAME_LONG "\n");
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	return 0;
}

void __exit rbd_exit(void)
{
	rbd_sysfs_cleanup();
}

module_init(rbd_init);
module_exit(rbd_exit);

MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
MODULE_DESCRIPTION("rados block device");

/* following authorship retained from original osdblk.c */
MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");

MODULE_LICENSE("GPL");