Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

Pull Ceph updates for 3.4-rc1 from Sage Weil:
 "Alex has been busy.  There are a range of rbd and libceph cleanups,
  especially surrounding device setup and teardown, and a few critical
  fixes in that code.  There are more cleanups in the messenger code,
  virtual xattrs, a fix for CRC calculation/checks, and lots of other
  miscellaneous stuff.

  There's a patch from Amon Ott to make inos behave a bit better on
  32-bit boxes, some decode check fixes from Xi Wang, and network
  throttling fix from Jim Schutt, and a couple RBD fixes from Josh
  Durgin.

  No new functionality, just a lot of cleanup and bug fixing."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (65 commits)
  rbd: move snap_rwsem to the device, rename to header_rwsem
  ceph: fix three bugs, two in ceph_vxattrcb_file_layout()
  libceph: isolate kmap() call in write_partial_msg_pages()
  libceph: rename "page_shift" variable to something sensible
  libceph: get rid of zero_page_address
  libceph: only call kernel_sendpage() via helper
  libceph: use kernel_sendpage() for sending zeroes
  libceph: fix inverted crc option logic
  libceph: some simple changes
  libceph: small refactor in write_partial_kvec()
  libceph: do crc calculations outside loop
  libceph: separate CRC calculation from byte swapping
  libceph: use "do" in CRC-related Boolean variables
  ceph: ensure Boolean options support both senses
  libceph: a few small changes
  libceph: make ceph_tcp_connect() return int
  libceph: encapsulate some messenger cleanup code
  libceph: make ceph_msgr_wq private
  libceph: encapsulate connection kvec operations
  libceph: move prepare_write_banner()
  ...

2 files changed, 448 insertions, 286 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index a6278e7e61a0..013c7a549fb6 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -41,19 +41,35 @@
 
 #include "rbd_types.h"
 
-#define DRV_NAME "rbd"
-#define DRV_NAME_LONG "rbd (rados block device)"
+/*
+ * 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)
+
+#define RBD_DRV_NAME "rbd"
+#define RBD_DRV_NAME_LONG "rbd (rados block device)"
 
 #define RBD_MINORS_PER_MAJOR	256		/* max minors per blkdev */
 
-#define RBD_MAX_MD_NAME_LEN	(96 + sizeof(RBD_SUFFIX))
+#define RBD_MAX_MD_NAME_LEN	(RBD_MAX_OBJ_NAME_LEN + sizeof(RBD_SUFFIX))
 #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	"-"
 
+/*
+ * 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.
+ */
 #define DEV_NAME_LEN		32
+#define MAX_INT_FORMAT_WIDTH	((5 * sizeof (int)) / 2 + 1)
 
 #define RBD_NOTIFY_TIMEOUT_DEFAULT 10
 
@@ -66,7 +82,6 @@ struct rbd_image_header {
 	__u8 obj_order;
 	__u8 crypt_type;
 	__u8 comp_type;
-	struct rw_semaphore snap_rwsem;
 	struct ceph_snap_context *snapc;
 	size_t snap_names_len;
 	u64 snap_seq;
@@ -83,7 +98,7 @@ struct rbd_options {
 };
 
 /*
- * an instance of the client.  multiple devices may share a client.
+ * an instance of the client.  multiple devices may share an rbd client.
  */
 struct rbd_client {
 	struct ceph_client	*client;
@@ -92,20 +107,9 @@ struct rbd_client {
 	struct list_head	node;
 };
 
-struct rbd_req_coll;
-
 /*
- * a single io request
+ * a request completion status
  */
-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;
-};
-
 struct rbd_req_status {
 	int done;
 	int rc;
@@ -122,6 +126,18 @@ struct rbd_req_coll {
 	struct rbd_req_status	status[0];
 };
 
+/*
+ * 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;
+};
+
 struct rbd_snap {
 	struct	device		dev;
 	const char		*name;
@@ -140,7 +156,6 @@ struct rbd_device {
 	struct gendisk		*disk;		/* blkdev's gendisk and rq */
 	struct request_queue	*q;
 
-	struct ceph_client	*client;
 	struct rbd_client	*rbd_client;
 
 	char			name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
@@ -157,6 +172,8 @@ struct rbd_device {
 	struct ceph_osd_event   *watch_event;
 	struct ceph_osd_request *watch_request;
 
+	/* protects updating the header */
+	struct rw_semaphore     header_rwsem;
 	char                    snap_name[RBD_MAX_SNAP_NAME_LEN];
 	u32 cur_snap;	/* index+1 of current snapshot within snap context
 			   0 - for the head */
@@ -171,15 +188,13 @@ struct rbd_device {
 	struct device		dev;
 };
 
-static struct bus_type rbd_bus_type = {
-	.name		= "rbd",
-};
-
-static spinlock_t node_lock;      /* protects client get/put */
-
 static DEFINE_MUTEX(ctl_mutex);	  /* Serialize open/close/setup/teardown */
+
 static LIST_HEAD(rbd_dev_list);    /* devices */
-static LIST_HEAD(rbd_client_list);      /* clients */
+static DEFINE_SPINLOCK(rbd_dev_list_lock);
+
+static LIST_HEAD(rbd_client_list);		/* clients */
+static DEFINE_SPINLOCK(rbd_client_list_lock);
 
 static int __rbd_init_snaps_header(struct rbd_device *rbd_dev);
 static void rbd_dev_release(struct device *dev);
@@ -190,12 +205,32 @@ static ssize_t rbd_snap_add(struct device *dev,
 static void __rbd_remove_snap_dev(struct rbd_device *rbd_dev,
 				  struct rbd_snap *snap);
 
+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 rbd_device *dev_to_rbd(struct device *dev)
+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)
 {
-	return container_of(dev, struct rbd_device, dev);
 }
 
+static struct device rbd_root_dev = {
+	.init_name =    "rbd",
+	.release =      rbd_root_dev_release,
+};
+
+
 static struct device *rbd_get_dev(struct rbd_device *rbd_dev)
 {
 	return get_device(&rbd_dev->dev);
@@ -210,8 +245,7 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev);
 
 static int rbd_open(struct block_device *bdev, fmode_t mode)
 {
-	struct gendisk *disk = bdev->bd_disk;
-	struct rbd_device *rbd_dev = disk->private_data;
+	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 
 	rbd_get_dev(rbd_dev);
 
@@ -256,9 +290,11 @@ static struct rbd_client *rbd_client_create(struct ceph_options *opt,
 	kref_init(&rbdc->kref);
 	INIT_LIST_HEAD(&rbdc->node);
 
+	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
 	rbdc->client = ceph_create_client(opt, rbdc, 0, 0);
 	if (IS_ERR(rbdc->client))
-		goto out_rbdc;
+		goto out_mutex;
 	opt = NULL; /* Now rbdc->client is responsible for opt */
 
 	ret = ceph_open_session(rbdc->client);
@@ -267,16 +303,19 @@ static struct rbd_client *rbd_client_create(struct ceph_options *opt,
 
 	rbdc->rbd_opts = rbd_opts;
 
-	spin_lock(&node_lock);
+	spin_lock(&rbd_client_list_lock);
 	list_add_tail(&rbdc->node, &rbd_client_list);
-	spin_unlock(&node_lock);
+	spin_unlock(&rbd_client_list_lock);
+
+	mutex_unlock(&ctl_mutex);
 
 	dout("rbd_client_create created %p\n", rbdc);
 	return rbdc;
 
 out_err:
 	ceph_destroy_client(rbdc->client);
-out_rbdc:
+out_mutex:
+	mutex_unlock(&ctl_mutex);
 	kfree(rbdc);
 out_opt:
 	if (opt)
@@ -324,7 +363,7 @@ static int parse_rbd_opts_token(char *c, void *private)
 	substring_t argstr[MAX_OPT_ARGS];
 	int token, intval, ret;
 
-	token = match_token((char *)c, rbdopt_tokens, argstr);
+	token = match_token(c, rbdopt_tokens, argstr);
 	if (token < 0)
 		return -EINVAL;
 
@@ -357,58 +396,54 @@ static int parse_rbd_opts_token(char *c, void *private)
  * Get a ceph client with specific addr and configuration, if one does
  * not exist create it.
  */
-static int rbd_get_client(struct rbd_device *rbd_dev, const char *mon_addr,
-			  char *options)
+static struct rbd_client *rbd_get_client(const char *mon_addr,
+					 size_t mon_addr_len,
+					 char *options)
 {
 	struct rbd_client *rbdc;
 	struct ceph_options *opt;
-	int ret;
 	struct rbd_options *rbd_opts;
 
 	rbd_opts = kzalloc(sizeof(*rbd_opts), GFP_KERNEL);
 	if (!rbd_opts)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	rbd_opts->notify_timeout = RBD_NOTIFY_TIMEOUT_DEFAULT;
 
-	ret = ceph_parse_options(&opt, options, mon_addr,
-				 mon_addr + strlen(mon_addr), parse_rbd_opts_token, rbd_opts);
-	if (ret < 0)
-		goto done_err;
+	opt = ceph_parse_options(options, mon_addr,
+				mon_addr + mon_addr_len,
+				parse_rbd_opts_token, rbd_opts);
+	if (IS_ERR(opt)) {
+		kfree(rbd_opts);
+		return ERR_CAST(opt);
+	}
 
-	spin_lock(&node_lock);
+	spin_lock(&rbd_client_list_lock);
 	rbdc = __rbd_client_find(opt);
 	if (rbdc) {
+		/* using an existing client */
+		kref_get(&rbdc->kref);
+		spin_unlock(&rbd_client_list_lock);
+
 		ceph_destroy_options(opt);
 		kfree(rbd_opts);
 
-		/* using an existing client */
-		kref_get(&rbdc->kref);
-		rbd_dev->rbd_client = rbdc;
-		rbd_dev->client = rbdc->client;
-		spin_unlock(&node_lock);
-		return 0;
+		return rbdc;
 	}
-	spin_unlock(&node_lock);
+	spin_unlock(&rbd_client_list_lock);
 
 	rbdc = rbd_client_create(opt, rbd_opts);
-	if (IS_ERR(rbdc)) {
-		ret = PTR_ERR(rbdc);
-		goto done_err;
-	}
 
-	rbd_dev->rbd_client = rbdc;
-	rbd_dev->client = rbdc->client;
-	return 0;
-done_err:
-	kfree(rbd_opts);
-	return ret;
+	if (IS_ERR(rbdc))
+		kfree(rbd_opts);
+
+	return rbdc;
 }
 
 /*
  * Destroy ceph client
  *
- * Caller must hold node_lock.
+ * Caller must hold rbd_client_list_lock.
  */
 static void rbd_client_release(struct kref *kref)
 {
@@ -428,11 +463,10 @@ static void rbd_client_release(struct kref *kref)
  */
 static void rbd_put_client(struct rbd_device *rbd_dev)
 {
-	spin_lock(&node_lock);
+	spin_lock(&rbd_client_list_lock);
 	kref_put(&rbd_dev->rbd_client->kref, rbd_client_release);
-	spin_unlock(&node_lock);
+	spin_unlock(&rbd_client_list_lock);
 	rbd_dev->rbd_client = NULL;
-	rbd_dev->client = NULL;
 }
 
 /*
@@ -457,21 +491,19 @@ static int rbd_header_from_disk(struct rbd_image_header *header,
 				 gfp_t gfp_flags)
 {
 	int i;
-	u32 snap_count = le32_to_cpu(ondisk->snap_count);
-	int ret = -ENOMEM;
+	u32 snap_count;
 
-	if (memcmp(ondisk, RBD_HEADER_TEXT, sizeof(RBD_HEADER_TEXT))) {
+	if (memcmp(ondisk, RBD_HEADER_TEXT, sizeof(RBD_HEADER_TEXT)))
 		return -ENXIO;
-	}
 
-	init_rwsem(&header->snap_rwsem);
-	header->snap_names_len = le64_to_cpu(ondisk->snap_names_len);
+	snap_count = le32_to_cpu(ondisk->snap_count);
 	header->snapc = kmalloc(sizeof(struct ceph_snap_context) +
-				snap_count *
-				 sizeof(struct rbd_image_snap_ondisk),
+				snap_count * sizeof (*ondisk),
 				gfp_flags);
 	if (!header->snapc)
 		return -ENOMEM;
+
+	header->snap_names_len = le64_to_cpu(ondisk->snap_names_len);
 	if (snap_count) {
 		header->snap_names = kmalloc(header->snap_names_len,
 					     GFP_KERNEL);
@@ -498,8 +530,7 @@ static int rbd_header_from_disk(struct rbd_image_header *header,
 	header->snapc->num_snaps = snap_count;
 	header->total_snaps = snap_count;
 
-	if (snap_count &&
-	    allocated_snaps == snap_count) {
+	if (snap_count && allocated_snaps == snap_count) {
 		for (i = 0; i < snap_count; i++) {
 			header->snapc->snaps[i] =
 				le64_to_cpu(ondisk->snaps[i].id);
@@ -518,7 +549,7 @@ err_names:
 	kfree(header->snap_names);
 err_snapc:
 	kfree(header->snapc);
-	return ret;
+	return -ENOMEM;
 }
 
 static int snap_index(struct rbd_image_header *header, int snap_num)
@@ -542,35 +573,34 @@ static int snap_by_name(struct rbd_image_header *header, const char *snap_name,
 	int i;
 	char *p = header->snap_names;
 
-	for (i = 0; i < header->total_snaps; i++, p += strlen(p) + 1) {
-		if (strcmp(snap_name, p) == 0)
-			break;
-	}
-	if (i == header->total_snaps)
-		return -ENOENT;
-	if (seq)
-		*seq = header->snapc->snaps[i];
+	for (i = 0; i < header->total_snaps; i++) {
+		if (!strcmp(snap_name, p)) {
 
-	if (size)
-		*size = header->snap_sizes[i];
+			/* Found it.  Pass back its id and/or size */
 
-	return i;
+			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;
 }
 
-static int rbd_header_set_snap(struct rbd_device *dev,
-			       const char *snap_name,
-			       u64 *size)
+static int rbd_header_set_snap(struct rbd_device *dev, u64 *size)
 {
 	struct rbd_image_header *header = &dev->header;
 	struct ceph_snap_context *snapc = header->snapc;
 	int ret = -ENOENT;
 
-	down_write(&header->snap_rwsem);
+	BUILD_BUG_ON(sizeof (dev->snap_name) < sizeof (RBD_SNAP_HEAD_NAME));
 
-	if (!snap_name ||
-	    !*snap_name ||
-	    strcmp(snap_name, "-") == 0 ||
-	    strcmp(snap_name, RBD_SNAP_HEAD_NAME) == 0) {
+	down_write(&dev->header_rwsem);
+
+	if (!memcmp(dev->snap_name, RBD_SNAP_HEAD_NAME,
+		    sizeof (RBD_SNAP_HEAD_NAME))) {
 		if (header->total_snaps)
 			snapc->seq = header->snap_seq;
 		else
@@ -580,7 +610,7 @@ static int rbd_header_set_snap(struct rbd_device *dev,
 		if (size)
 			*size = header->image_size;
 	} else {
-		ret = snap_by_name(header, snap_name, &snapc->seq, size);
+		ret = snap_by_name(header, dev->snap_name, &snapc->seq, size);
 		if (ret < 0)
 			goto done;
 
@@ -590,7 +620,7 @@ static int rbd_header_set_snap(struct rbd_device *dev,
 
 	ret = 0;
 done:
-	up_write(&header->snap_rwsem);
+	up_write(&dev->header_rwsem);
 	return ret;
 }
 
@@ -717,7 +747,7 @@ static struct bio *bio_chain_clone(struct bio **old, struct bio **next,
 
 			/* split the bio. We'll release it either in the next
 			   call, or it will have to be released outside */
-			bp = bio_split(old_chain, (len - total) / 512ULL);
+			bp = bio_split(old_chain, (len - total) / SECTOR_SIZE);
 			if (!bp)
 				goto err_out;
 
@@ -857,7 +887,7 @@ static int rbd_do_request(struct request *rq,
 	struct timespec mtime = CURRENT_TIME;
 	struct rbd_request *req_data;
 	struct ceph_osd_request_head *reqhead;
-	struct rbd_image_header *header = &dev->header;
+	struct ceph_osd_client *osdc;
 
 	req_data = kzalloc(sizeof(*req_data), GFP_NOIO);
 	if (!req_data) {
@@ -874,15 +904,13 @@ static int rbd_do_request(struct request *rq,
 
 	dout("rbd_do_request obj=%s ofs=%lld len=%lld\n", obj, len, ofs);
 
-	down_read(&header->snap_rwsem);
+	down_read(&dev->header_rwsem);
 
-	req = ceph_osdc_alloc_request(&dev->client->osdc, flags,
-				      snapc,
-				      ops,
-				      false,
-				      GFP_NOIO, pages, bio);
+	osdc = &dev->rbd_client->client->osdc;
+	req = ceph_osdc_alloc_request(osdc, flags, snapc, ops,
+					false, GFP_NOIO, pages, bio);
 	if (!req) {
-		up_read(&header->snap_rwsem);
+		up_read(&dev->header_rwsem);
 		ret = -ENOMEM;
 		goto done_pages;
 	}
@@ -909,27 +937,27 @@ static int rbd_do_request(struct request *rq,
 	layout->fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
 	layout->fl_pg_preferred = cpu_to_le32(-1);
 	layout->fl_pg_pool = cpu_to_le32(dev->poolid);
-	ceph_calc_raw_layout(&dev->client->osdc, layout, snapid,
-			     ofs, &len, &bno, req, ops);
+	ceph_calc_raw_layout(osdc, layout, snapid, ofs, &len, &bno,
+				req, ops);
 
 	ceph_osdc_build_request(req, ofs, &len,
 				ops,
 				snapc,
 				&mtime,
 				req->r_oid, req->r_oid_len);
-	up_read(&header->snap_rwsem);
+	up_read(&dev->header_rwsem);
 
 	if (linger_req) {
-		ceph_osdc_set_request_linger(&dev->client->osdc, req);
+		ceph_osdc_set_request_linger(osdc, req);
 		*linger_req = req;
 	}
 
-	ret = ceph_osdc_start_request(&dev->client->osdc, req, false);
+	ret = ceph_osdc_start_request(osdc, req, false);
 	if (ret < 0)
 		goto done_err;
 
 	if (!rbd_cb) {
-		ret = ceph_osdc_wait_request(&dev->client->osdc, req);
+		ret = ceph_osdc_wait_request(osdc, req);
 		if (ver)
 			*ver = le64_to_cpu(req->r_reassert_version.version);
 		dout("reassert_ver=%lld\n",
@@ -1213,8 +1241,8 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
 	rc = __rbd_update_snaps(dev);
 	mutex_unlock(&ctl_mutex);
 	if (rc)
-		pr_warning(DRV_NAME "%d got notification but failed to update"
-			   " snaps: %d\n", dev->major, rc);
+		pr_warning(RBD_DRV_NAME "%d got notification but failed to "
+			   " update snaps: %d\n", dev->major, rc);
 
 	rbd_req_sync_notify_ack(dev, ver, notify_id, dev->obj_md_name);
 }
@@ -1227,7 +1255,7 @@ static int rbd_req_sync_watch(struct rbd_device *dev,
 			      u64 ver)
 {
 	struct ceph_osd_req_op *ops;
-	struct ceph_osd_client *osdc = &dev->client->osdc;
+	struct ceph_osd_client *osdc = &dev->rbd_client->client->osdc;
 
 	int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_WATCH, 0);
 	if (ret < 0)
@@ -1314,7 +1342,7 @@ static int rbd_req_sync_notify(struct rbd_device *dev,
 		          const char *obj)
 {
 	struct ceph_osd_req_op *ops;
-	struct ceph_osd_client *osdc = &dev->client->osdc;
+	struct ceph_osd_client *osdc = &dev->rbd_client->client->osdc;
 	struct ceph_osd_event *event;
 	struct rbd_notify_info info;
 	int payload_len = sizeof(u32) + sizeof(u32);
@@ -1421,9 +1449,7 @@ static void rbd_rq_fn(struct request_queue *q)
 	struct request *rq;
 	struct bio_pair *bp = NULL;
 
-	rq = blk_fetch_request(q);
-
-	while (1) {
+	while ((rq = blk_fetch_request(q))) {
 		struct bio *bio;
 		struct bio *rq_bio, *next_bio = NULL;
 		bool do_write;
@@ -1441,32 +1467,32 @@ static void rbd_rq_fn(struct request_queue *q)
 		/* filter out block requests we don't understand */
 		if ((rq->cmd_type != REQ_TYPE_FS)) {
 			__blk_end_request_all(rq, 0);
-			goto next;
+			continue;
 		}
 
 		/* deduce our operation (read, write) */
 		do_write = (rq_data_dir(rq) == WRITE);
 
 		size = blk_rq_bytes(rq);
-		ofs = blk_rq_pos(rq) * 512ULL;
+		ofs = blk_rq_pos(rq) * SECTOR_SIZE;
 		rq_bio = rq->bio;
 		if (do_write && rbd_dev->read_only) {
 			__blk_end_request_all(rq, -EROFS);
-			goto next;
+			continue;
 		}
 
 		spin_unlock_irq(q->queue_lock);
 
 		dout("%s 0x%x bytes at 0x%llx\n",
 		     do_write ? "write" : "read",
-		     size, blk_rq_pos(rq) * 512ULL);
+		     size, blk_rq_pos(rq) * SECTOR_SIZE);
 
 		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);
-			goto next;
+			continue;
 		}
 
 		do {
@@ -1512,8 +1538,6 @@ next_seg:
 		if (bp)
 			bio_pair_release(bp);
 		spin_lock_irq(q->queue_lock);
-next:
-		rq = blk_fetch_request(q);
 	}
 }
 
@@ -1526,13 +1550,17 @@ 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;
-	unsigned int chunk_sectors = 1 << (rbd_dev->header.obj_order - 9);
-	sector_t sector = bmd->bi_sector + get_start_sect(bmd->bi_bdev);
-	unsigned int bio_sectors = bmd->bi_size >> 9;
+	unsigned int chunk_sectors;
+	sector_t sector;
+	unsigned int bio_sectors;
 	int max;
 
+	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;
+
 	max =  (chunk_sectors - ((sector & (chunk_sectors - 1))
-				 + bio_sectors)) << 9;
+				 + bio_sectors)) << SECTOR_SHIFT;
 	if (max < 0)
 		max = 0; /* bio_add cannot handle a negative return */
 	if (max <= bvec->bv_len && bio_sectors == 0)
@@ -1565,15 +1593,16 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
 	ssize_t rc;
 	struct rbd_image_header_ondisk *dh;
 	int snap_count = 0;
-	u64 snap_names_len = 0;
 	u64 ver;
+	size_t len;
 
+	/*
+	 * 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);
 	while (1) {
-		int len = sizeof(*dh) +
-			  snap_count * sizeof(struct rbd_image_snap_ondisk) +
-			  snap_names_len;
-
-		rc = -ENOMEM;
 		dh = kmalloc(len, GFP_KERNEL);
 		if (!dh)
 			return -ENOMEM;
@@ -1588,21 +1617,22 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
 
 		rc = rbd_header_from_disk(header, dh, snap_count, GFP_KERNEL);
 		if (rc < 0) {
-			if (rc == -ENXIO) {
+			if (rc == -ENXIO)
 				pr_warning("unrecognized header format"
 					   " for image %s", rbd_dev->obj);
-			}
 			goto out_dh;
 		}
 
-		if (snap_count != header->total_snaps) {
-			snap_count = header->total_snaps;
-			snap_names_len = header->snap_names_len;
-			rbd_header_free(header);
-			kfree(dh);
-			continue;
-		}
-		break;
+		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);
 	}
 	header->obj_version = ver;
 
@@ -1623,13 +1653,14 @@ static int rbd_header_add_snap(struct rbd_device *dev,
 	int ret;
 	void *data, *p, *e;
 	u64 ver;
+	struct ceph_mon_client *monc;
 
 	/* we should create a snapshot only if we're pointing at the head */
 	if (dev->cur_snap)
 		return -EINVAL;
 
-	ret = ceph_monc_create_snapid(&dev->client->monc, dev->poolid,
-				      &new_snapid);
+	monc = &dev->rbd_client->client->monc;
+	ret = ceph_monc_create_snapid(monc, dev->poolid, &new_snapid);
 	dout("created snapid=%lld\n", new_snapid);
 	if (ret < 0)
 		return ret;
@@ -1684,9 +1715,9 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev)
 		return ret;
 
 	/* resized? */
-	set_capacity(rbd_dev->disk, h.image_size / 512ULL);
+	set_capacity(rbd_dev->disk, h.image_size / SECTOR_SIZE);
 
-	down_write(&rbd_dev->header.snap_rwsem);
+	down_write(&rbd_dev->header_rwsem);
 
 	snap_seq = rbd_dev->header.snapc->seq;
 	if (rbd_dev->header.total_snaps &&
@@ -1711,7 +1742,7 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev)
 
 	ret = __rbd_init_snaps_header(rbd_dev);
 
-	up_write(&rbd_dev->header.snap_rwsem);
+	up_write(&rbd_dev->header_rwsem);
 
 	return ret;
 }
@@ -1721,6 +1752,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
 	struct gendisk *disk;
 	struct request_queue *q;
 	int rc;
+	u64 segment_size;
 	u64 total_size = 0;
 
 	/* contact OSD, request size info about the object being mapped */
@@ -1733,7 +1765,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
 	if (rc)
 		return rc;
 
-	rc = rbd_header_set_snap(rbd_dev, rbd_dev->snap_name, &total_size);
+	rc = rbd_header_set_snap(rbd_dev, &total_size);
 	if (rc)
 		return rc;
 
@@ -1743,7 +1775,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
 	if (!disk)
 		goto out;
 
-	snprintf(disk->disk_name, sizeof(disk->disk_name), DRV_NAME "%d",
+	snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
 		 rbd_dev->id);
 	disk->major = rbd_dev->major;
 	disk->first_minor = 0;
@@ -1756,11 +1788,15 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
 	if (!q)
 		goto out_disk;
 
+	/* We use the default size, but let's be explicit about it. */
+	blk_queue_physical_block_size(q, SECTOR_SIZE);
+
 	/* set io sizes to object size */
-	blk_queue_max_hw_sectors(q, rbd_obj_bytes(&rbd_dev->header) / 512ULL);
-	blk_queue_max_segment_size(q, rbd_obj_bytes(&rbd_dev->header));
-	blk_queue_io_min(q, rbd_obj_bytes(&rbd_dev->header));
-	blk_queue_io_opt(q, rbd_obj_bytes(&rbd_dev->header));
+	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);
 
 	blk_queue_merge_bvec(q, rbd_merge_bvec);
 	disk->queue = q;
@@ -1771,7 +1807,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
 	rbd_dev->q = q;
 
 	/* finally, announce the disk to the world */
-	set_capacity(disk, total_size / 512ULL);
+	set_capacity(disk, total_size / SECTOR_SIZE);
 	add_disk(disk);
 
 	pr_info("%s: added with size 0x%llx\n",
@@ -1788,10 +1824,15 @@ out:
   sysfs
 */
 
+static struct rbd_device *dev_to_rbd_dev(struct device *dev)
+{
+	return container_of(dev, struct rbd_device, dev);
+}
+
 static ssize_t rbd_size_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
 	return sprintf(buf, "%llu\n", (unsigned long long)rbd_dev->header.image_size);
 }
@@ -1799,7 +1840,7 @@ static ssize_t rbd_size_show(struct device *dev,
 static ssize_t rbd_major_show(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
 	return sprintf(buf, "%d\n", rbd_dev->major);
 }
@@ -1807,15 +1848,16 @@ static ssize_t rbd_major_show(struct device *dev,
 static ssize_t rbd_client_id_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
-	return sprintf(buf, "client%lld\n", ceph_client_id(rbd_dev->client));
+	return sprintf(buf, "client%lld\n",
+			ceph_client_id(rbd_dev->rbd_client->client));
 }
 
 static ssize_t rbd_pool_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
 	return sprintf(buf, "%s\n", rbd_dev->pool_name);
 }
@@ -1823,7 +1865,7 @@ static ssize_t rbd_pool_show(struct device *dev,
 static ssize_t rbd_name_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
 	return sprintf(buf, "%s\n", rbd_dev->obj);
 }
@@ -1832,7 +1874,7 @@ static ssize_t rbd_snap_show(struct device *dev,
 			     struct device_attribute *attr,
 			     char *buf)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
 	return sprintf(buf, "%s\n", rbd_dev->snap_name);
 }
@@ -1842,7 +1884,7 @@ static ssize_t rbd_image_refresh(struct device *dev,
 				 const char *buf,
 				 size_t size)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 	int rc;
 	int ret = size;
 
@@ -1907,7 +1949,7 @@ static ssize_t rbd_snap_size_show(struct device *dev,
 {
 	struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
 
-	return sprintf(buf, "%lld\n", (long long)snap->size);
+	return sprintf(buf, "%zd\n", snap->size);
 }
 
 static ssize_t rbd_snap_id_show(struct device *dev,
@@ -1916,7 +1958,7 @@ static ssize_t rbd_snap_id_show(struct device *dev,
 {
 	struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
 
-	return sprintf(buf, "%lld\n", (long long)snap->id);
+	return sprintf(buf, "%llu\n", (unsigned long long) snap->id);
 }
 
 static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL);
@@ -2088,19 +2130,9 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
 	return 0;
 }
 
-
-static void rbd_root_dev_release(struct device *dev)
-{
-}
-
-static struct device rbd_root_dev = {
-	.init_name =    "rbd",
-	.release =      rbd_root_dev_release,
-};
-
 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
 {
-	int ret = -ENOMEM;
+	int ret;
 	struct device *dev;
 	struct rbd_snap *snap;
 
@@ -2114,7 +2146,7 @@ static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
 	dev_set_name(dev, "%d", rbd_dev->id);
 	ret = device_register(dev);
 	if (ret < 0)
-		goto done_free;
+		goto out;
 
 	list_for_each_entry(snap, &rbd_dev->snaps, node) {
 		ret = rbd_register_snap_dev(rbd_dev, snap,
@@ -2122,10 +2154,7 @@ static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
 		if (ret < 0)
 			break;
 	}
-
-	mutex_unlock(&ctl_mutex);
-	return 0;
-done_free:
+out:
 	mutex_unlock(&ctl_mutex);
 	return ret;
 }
@@ -2154,104 +2183,250 @@ static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
 	return ret;
 }
 
+static atomic64_t rbd_id_max = ATOMIC64_INIT(0);
+
+/*
+ * 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.
+ */
+static void rbd_id_get(struct rbd_device *rbd_dev)
+{
+	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);
+}
+
+/*
+ * Remove an rbd_dev from the global list, and record that its
+ * identifier is no longer in use.
+ */
+static void rbd_id_put(struct rbd_device *rbd_dev)
+{
+	struct list_head *tmp;
+	int rbd_id = rbd_dev->id;
+	int max_id;
+
+	BUG_ON(rbd_id < 1);
+
+	spin_lock(&rbd_dev_list_lock);
+	list_del_init(&rbd_dev->node);
+
+	/*
+	 * 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;
+	}
+	spin_unlock(&rbd_dev_list_lock);
+
+	/*
+	 * 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.
+	 */
+	atomic64_cmpxchg(&rbd_id_max, rbd_id, max_id);
+}
+
+/*
+ * Skips over white space at *buf, and updates *buf to point to the
+ * first found non-space character (if any). Returns the length of
+ * the token (string of non-white space characters) found.  Note
+ * that *buf must be terminated with '\0'.
+ */
+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
+ * copied, is guaranteed to be terminated with '\0'.  Note that *buf
+ * must be terminated with '\0' on entry.
+ *
+ * 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.
+ *
+ * The *buf pointer will be updated to point beyond the end of the
+ * 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;
+}
+
+/*
+ * 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,
+			      const char **mon_addrs,
+			      size_t *mon_addrs_size,
+			      char *options,
+			      size_t options_size)
+{
+	size_t	len;
+
+	/* The first four tokens are required */
+
+	len = next_token(&buf);
+	if (!len)
+		return -EINVAL;
+	*mon_addrs_size = len + 1;
+	*mon_addrs = buf;
+
+	buf += len;
+
+	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;
+
+	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);
+
+	/*
+	 * 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;
+
+	return 0;
+}
+
 static ssize_t rbd_add(struct bus_type *bus,
 		       const char *buf,
 		       size_t count)
 {
-	struct ceph_osd_client *osdc;
 	struct rbd_device *rbd_dev;
-	ssize_t rc = -ENOMEM;
-	int irc, new_id = 0;
-	struct list_head *tmp;
-	char *mon_dev_name;
-	char *options;
+	const char *mon_addrs = NULL;
+	size_t mon_addrs_size = 0;
+	char *options = NULL;
+	struct ceph_osd_client *osdc;
+	int rc = -ENOMEM;
 
 	if (!try_module_get(THIS_MODULE))
 		return -ENODEV;
 
-	mon_dev_name = kmalloc(RBD_MAX_OPT_LEN, GFP_KERNEL);
-	if (!mon_dev_name)
-		goto err_out_mod;
-
-	options = kmalloc(RBD_MAX_OPT_LEN, GFP_KERNEL);
-	if (!options)
-		goto err_mon_dev;
-
-	/* new rbd_device object */
 	rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
 	if (!rbd_dev)
-		goto err_out_opt;
+		goto err_nomem;
+	options = kmalloc(count, GFP_KERNEL);
+	if (!options)
+		goto err_nomem;
 
 	/* static rbd_device initialization */
 	spin_lock_init(&rbd_dev->lock);
 	INIT_LIST_HEAD(&rbd_dev->node);
 	INIT_LIST_HEAD(&rbd_dev->snaps);
+	init_rwsem(&rbd_dev->header_rwsem);
 
-	init_rwsem(&rbd_dev->header.snap_rwsem);
+	init_rwsem(&rbd_dev->header_rwsem);
 
 	/* generate unique id: find highest unique id, add one */
-	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-
-	list_for_each(tmp, &rbd_dev_list) {
-		struct rbd_device *rbd_dev;
+	rbd_id_get(rbd_dev);
 
-		rbd_dev = list_entry(tmp, struct rbd_device, node);
-		if (rbd_dev->id >= new_id)
-			new_id = rbd_dev->id + 1;
-	}
-
-	rbd_dev->id = new_id;
-
-	/* add to global list */
-	list_add_tail(&rbd_dev->node, &rbd_dev_list);
+	/* Fill in the device name, now that we have its id. */
+	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);
 
 	/* parse add command */
-	if (sscanf(buf, "%" __stringify(RBD_MAX_OPT_LEN) "s "
-		   "%" __stringify(RBD_MAX_OPT_LEN) "s "
-		   "%" __stringify(RBD_MAX_POOL_NAME_LEN) "s "
-		   "%" __stringify(RBD_MAX_OBJ_NAME_LEN) "s"
-		   "%" __stringify(RBD_MAX_SNAP_NAME_LEN) "s",
-		   mon_dev_name, options, rbd_dev->pool_name,
-		   rbd_dev->obj, rbd_dev->snap_name) < 4) {
-		rc = -EINVAL;
-		goto err_out_slot;
-	}
-
-	if (rbd_dev->snap_name[0] == 0)
-		rbd_dev->snap_name[0] = '-';
-
-	rbd_dev->obj_len = strlen(rbd_dev->obj);
-	snprintf(rbd_dev->obj_md_name, sizeof(rbd_dev->obj_md_name), "%s%s",
-		 rbd_dev->obj, RBD_SUFFIX);
-
-	/* initialize rest of new object */
-	snprintf(rbd_dev->name, DEV_NAME_LEN, DRV_NAME "%d", rbd_dev->id);
-	rc = rbd_get_client(rbd_dev, mon_dev_name, options);
-	if (rc < 0)
-		goto err_out_slot;
+	rc = rbd_add_parse_args(rbd_dev, buf, &mon_addrs, &mon_addrs_size,
+				options, count);
+	if (rc)
+		goto err_put_id;
 
-	mutex_unlock(&ctl_mutex);
+	rbd_dev->rbd_client = rbd_get_client(mon_addrs, mon_addrs_size - 1,
+						options);
+	if (IS_ERR(rbd_dev->rbd_client)) {
+		rc = PTR_ERR(rbd_dev->rbd_client);
+		goto err_put_id;
+	}
 
 	/* pick the pool */
-	osdc = &rbd_dev->client->osdc;
+	osdc = &rbd_dev->rbd_client->client->osdc;
 	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 */
-	irc = register_blkdev(0, rbd_dev->name);
-	if (irc < 0) {
-		rc = irc;
+	rc = register_blkdev(0, rbd_dev->name);
+	if (rc < 0)
 		goto err_out_client;
-	}
-	rbd_dev->major = irc;
+	rbd_dev->major = rc;
 
 	rc = rbd_bus_add_dev(rbd_dev);
 	if (rc)
 		goto err_out_blkdev;
 
-	/* set up and announce blkdev mapping */
+	/*
+	 * 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.
+	 */
 	rc = rbd_init_disk(rbd_dev);
 	if (rc)
 		goto err_out_bus;
@@ -2263,35 +2438,26 @@ static ssize_t rbd_add(struct bus_type *bus,
 	return count;
 
 err_out_bus:
-	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-	list_del_init(&rbd_dev->node);
-	mutex_unlock(&ctl_mutex);
-
 	/* this will also clean up rest of rbd_dev stuff */
 
 	rbd_bus_del_dev(rbd_dev);
 	kfree(options);
-	kfree(mon_dev_name);
 	return rc;
 
 err_out_blkdev:
 	unregister_blkdev(rbd_dev->major, rbd_dev->name);
 err_out_client:
 	rbd_put_client(rbd_dev);
-	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-err_out_slot:
-	list_del_init(&rbd_dev->node);
-	mutex_unlock(&ctl_mutex);
-
-	kfree(rbd_dev);
-err_out_opt:
+err_put_id:
+	rbd_id_put(rbd_dev);
+err_nomem:
 	kfree(options);
-err_mon_dev:
-	kfree(mon_dev_name);
-err_out_mod:
+	kfree(rbd_dev);
+
 	dout("Error adding device %s\n", buf);
 	module_put(THIS_MODULE);
-	return rc;
+
+	return (ssize_t) rc;
 }
 
 static struct rbd_device *__rbd_get_dev(unsigned long id)
@@ -2299,22 +2465,28 @@ static struct rbd_device *__rbd_get_dev(unsigned long id)
 	struct list_head *tmp;
 	struct rbd_device *rbd_dev;
 
+	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->id == id)
+		if (rbd_dev->id == id) {
+			spin_unlock(&rbd_dev_list_lock);
 			return rbd_dev;
+		}
 	}
+	spin_unlock(&rbd_dev_list_lock);
 	return NULL;
 }
 
 static void rbd_dev_release(struct device *dev)
 {
-	struct rbd_device *rbd_dev =
-			container_of(dev, struct rbd_device, dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 
-	if (rbd_dev->watch_request)
-		ceph_osdc_unregister_linger_request(&rbd_dev->client->osdc,
+	if (rbd_dev->watch_request) {
+		struct ceph_client *client = rbd_dev->rbd_client->client;
+
+		ceph_osdc_unregister_linger_request(&client->osdc,
 						    rbd_dev->watch_request);
+	}
 	if (rbd_dev->watch_event)
 		rbd_req_sync_unwatch(rbd_dev, rbd_dev->obj_md_name);
 
@@ -2323,6 +2495,9 @@ static void rbd_dev_release(struct device *dev)
 	/* clean up and free blkdev */
 	rbd_free_disk(rbd_dev);
 	unregister_blkdev(rbd_dev->major, rbd_dev->name);
+
+	/* done with the id, and with the rbd_dev */
+	rbd_id_put(rbd_dev);
 	kfree(rbd_dev);
 
 	/* release module ref */
@@ -2355,8 +2530,6 @@ static ssize_t rbd_remove(struct bus_type *bus,
 		goto done;
 	}
 
-	list_del_init(&rbd_dev->node);
-
 	__rbd_remove_all_snaps(rbd_dev);
 	rbd_bus_del_dev(rbd_dev);
 
@@ -2370,7 +2543,7 @@ static ssize_t rbd_snap_add(struct device *dev,
 			    const char *buf,
 			    size_t count)
 {
-	struct rbd_device *rbd_dev = dev_to_rbd(dev);
+	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
 	int ret;
 	char *name = kmalloc(count + 1, GFP_KERNEL);
 	if (!name)
@@ -2406,12 +2579,6 @@ err_unlock:
 	return ret;
 }
 
-static struct bus_attribute rbd_bus_attrs[] = {
-	__ATTR(add, S_IWUSR, NULL, rbd_add),
-	__ATTR(remove, S_IWUSR, NULL, rbd_remove),
-	__ATTR_NULL
-};
-
 /*
  * create control files in sysfs
  * /sys/bus/rbd/...
@@ -2420,21 +2587,21 @@ static int rbd_sysfs_init(void)
 {
 	int ret;
 
-	rbd_bus_type.bus_attrs = rbd_bus_attrs;
-
-	ret = bus_register(&rbd_bus_type);
-	 if (ret < 0)
+	ret = device_register(&rbd_root_dev);
+	if (ret < 0)
 		return ret;
 
-	ret = device_register(&rbd_root_dev);
+	ret = bus_register(&rbd_bus_type);
+	if (ret < 0)
+		device_unregister(&rbd_root_dev);
 
 	return ret;
 }
 
 static void rbd_sysfs_cleanup(void)
 {
-	device_unregister(&rbd_root_dev);
 	bus_unregister(&rbd_bus_type);
+	device_unregister(&rbd_root_dev);
 }
 
 int __init rbd_init(void)
@@ -2444,8 +2611,7 @@ int __init rbd_init(void)
 	rc = rbd_sysfs_init();
 	if (rc)
 		return rc;
-	spin_lock_init(&node_lock);
-	pr_info("loaded " DRV_NAME_LONG "\n");
+	pr_info("loaded " RBD_DRV_NAME_LONG "\n");
 	return 0;
 }
 
diff --git a/drivers/block/rbd_types.h b/drivers/block/rbd_types.h
index fc6c678aa2cb..950708688f17 100644
--- a/drivers/block/rbd_types.h
+++ b/drivers/block/rbd_types.h
@@ -41,10 +41,6 @@
 #define RBD_HEADER_SIGNATURE	"RBD"
 #define RBD_HEADER_VERSION	"001.005"
 
-struct rbd_info {
-	__le64 max_id;
-} __attribute__ ((packed));
-
 struct rbd_image_snap_ondisk {
 	__le64 id;
 	__le64 image_size;