3 rbd.c -- Export ceph rados objects as a Linux block device
6 based on drivers/block/osdblk.c:
8 Copyright 2009 Red Hat, Inc.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; see the file COPYING. If not, write to
21 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25 For usage instructions, please refer to:
27 Documentation/ABI/testing/sysfs-bus-rbd
31 #include <linux/ceph/libceph.h>
32 #include <linux/ceph/osd_client.h>
33 #include <linux/ceph/mon_client.h>
34 #include <linux/ceph/decode.h>
35 #include <linux/parser.h>
36 #include <linux/bsearch.h>
38 #include <linux/kernel.h>
39 #include <linux/device.h>
40 #include <linux/module.h>
42 #include <linux/blkdev.h>
43 #include <linux/slab.h>
45 #include "rbd_types.h"
47 #define RBD_DEBUG /* Activate rbd_assert() calls */
50 * The basic unit of block I/O is a sector. It is interpreted in a
51 * number of contexts in Linux (blk, bio, genhd), but the default is
52 * universally 512 bytes. These symbols are just slightly more
53 * meaningful than the bare numbers they represent.
55 #define SECTOR_SHIFT 9
56 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT)
59 * Increment the given counter and return its updated value.
60 * If the counter is already 0 it will not be incremented.
61 * If the counter is already at its maximum value returns
62 * -EINVAL without updating it.
64 static int atomic_inc_return_safe(atomic_t *v)
68 counter = (unsigned int)__atomic_add_unless(v, 1, 0);
69 if (counter <= (unsigned int)INT_MAX)
77 /* Decrement the counter. Return the resulting value, or -EINVAL */
78 static int atomic_dec_return_safe(atomic_t *v)
82 counter = atomic_dec_return(v);
91 #define RBD_DRV_NAME "rbd"
92 #define RBD_DRV_NAME_LONG "rbd (rados block device)"
94 #define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
96 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
97 #define RBD_MAX_SNAP_NAME_LEN \
98 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
100 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
102 #define RBD_SNAP_HEAD_NAME "-"
104 #define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
106 /* This allows a single page to hold an image name sent by OSD */
107 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
108 #define RBD_IMAGE_ID_LEN_MAX 64
110 #define RBD_OBJ_PREFIX_LEN_MAX 64
114 #define RBD_FEATURE_LAYERING (1<<0)
115 #define RBD_FEATURE_STRIPINGV2 (1<<1)
116 #define RBD_FEATURES_ALL \
117 (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
119 /* Features supported by this (client software) implementation. */
121 #define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
124 * An RBD device name will be "rbd#", where the "rbd" comes from
125 * RBD_DRV_NAME above, and # is a unique integer identifier.
126 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
127 * enough to hold all possible device names.
129 #define DEV_NAME_LEN 32
130 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
133 * block device image metadata (in-memory version)
135 struct rbd_image_header {
136 /* These six fields never change for a given rbd image */
143 u64 features; /* Might be changeable someday? */
145 /* The remaining fields need to be updated occasionally */
147 struct ceph_snap_context *snapc;
148 char *snap_names; /* format 1 only */
149 u64 *snap_sizes; /* format 1 only */
153 * An rbd image specification.
155 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
156 * identify an image. Each rbd_dev structure includes a pointer to
157 * an rbd_spec structure that encapsulates this identity.
159 * Each of the id's in an rbd_spec has an associated name. For a
160 * user-mapped image, the names are supplied and the id's associated
161 * with them are looked up. For a layered image, a parent image is
162 * defined by the tuple, and the names are looked up.
164 * An rbd_dev structure contains a parent_spec pointer which is
165 * non-null if the image it represents is a child in a layered
166 * image. This pointer will refer to the rbd_spec structure used
167 * by the parent rbd_dev for its own identity (i.e., the structure
168 * is shared between the parent and child).
170 * Since these structures are populated once, during the discovery
171 * phase of image construction, they are effectively immutable so
172 * we make no effort to synchronize access to them.
174 * Note that code herein does not assume the image name is known (it
175 * could be a null pointer).
179 const char *pool_name;
181 const char *image_id;
182 const char *image_name;
185 const char *snap_name;
191 * an instance of the client. multiple devices may share an rbd client.
194 struct ceph_client *client;
196 struct list_head node;
199 struct rbd_img_request;
200 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
202 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
204 struct rbd_obj_request;
205 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
207 enum obj_request_type {
208 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
212 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
213 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
214 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
215 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
218 struct rbd_obj_request {
219 const char *object_name;
220 u64 offset; /* object start byte */
221 u64 length; /* bytes from offset */
225 * An object request associated with an image will have its
226 * img_data flag set; a standalone object request will not.
228 * A standalone object request will have which == BAD_WHICH
229 * and a null obj_request pointer.
231 * An object request initiated in support of a layered image
232 * object (to check for its existence before a write) will
233 * have which == BAD_WHICH and a non-null obj_request pointer.
235 * Finally, an object request for rbd image data will have
236 * which != BAD_WHICH, and will have a non-null img_request
237 * pointer. The value of which will be in the range
238 * 0..(img_request->obj_request_count-1).
241 struct rbd_obj_request *obj_request; /* STAT op */
243 struct rbd_img_request *img_request;
245 /* links for img_request->obj_requests list */
246 struct list_head links;
249 u32 which; /* posn image request list */
251 enum obj_request_type type;
253 struct bio *bio_list;
259 struct page **copyup_pages;
260 u32 copyup_page_count;
262 struct ceph_osd_request *osd_req;
264 u64 xferred; /* bytes transferred */
267 rbd_obj_callback_t callback;
268 struct completion completion;
274 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
275 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
276 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
279 struct rbd_img_request {
280 struct rbd_device *rbd_dev;
281 u64 offset; /* starting image byte offset */
282 u64 length; /* byte count from offset */
285 u64 snap_id; /* for reads */
286 struct ceph_snap_context *snapc; /* for writes */
289 struct request *rq; /* block request */
290 struct rbd_obj_request *obj_request; /* obj req initiator */
292 struct page **copyup_pages;
293 u32 copyup_page_count;
294 spinlock_t completion_lock;/* protects next_completion */
296 rbd_img_callback_t callback;
297 u64 xferred;/* aggregate bytes transferred */
298 int result; /* first nonzero obj_request result */
300 u32 obj_request_count;
301 struct list_head obj_requests; /* rbd_obj_request structs */
306 #define for_each_obj_request(ireq, oreq) \
307 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
308 #define for_each_obj_request_from(ireq, oreq) \
309 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
310 #define for_each_obj_request_safe(ireq, oreq, n) \
311 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
323 int dev_id; /* blkdev unique id */
325 int major; /* blkdev assigned major */
326 struct gendisk *disk; /* blkdev's gendisk and rq */
328 u32 image_format; /* Either 1 or 2 */
329 struct rbd_client *rbd_client;
331 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
333 spinlock_t lock; /* queue, flags, open_count */
335 struct rbd_image_header header;
336 unsigned long flags; /* possibly lock protected */
337 struct rbd_spec *spec;
341 struct ceph_file_layout layout;
343 struct ceph_osd_event *watch_event;
344 struct rbd_obj_request *watch_request;
346 struct rbd_spec *parent_spec;
349 struct rbd_device *parent;
351 /* protects updating the header */
352 struct rw_semaphore header_rwsem;
354 struct rbd_mapping mapping;
356 struct list_head node;
360 unsigned long open_count; /* protected by lock */
364 * Flag bits for rbd_dev->flags. If atomicity is required,
365 * rbd_dev->lock is used to protect access.
367 * Currently, only the "removing" flag (which is coupled with the
368 * "open_count" field) requires atomic access.
371 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
372 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
375 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
377 static LIST_HEAD(rbd_dev_list); /* devices */
378 static DEFINE_SPINLOCK(rbd_dev_list_lock);
380 static LIST_HEAD(rbd_client_list); /* clients */
381 static DEFINE_SPINLOCK(rbd_client_list_lock);
383 /* Slab caches for frequently-allocated structures */
385 static struct kmem_cache *rbd_img_request_cache;
386 static struct kmem_cache *rbd_obj_request_cache;
387 static struct kmem_cache *rbd_segment_name_cache;
389 static int rbd_img_request_submit(struct rbd_img_request *img_request);
391 static void rbd_dev_device_release(struct device *dev);
393 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
395 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
397 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping);
398 static void rbd_spec_put(struct rbd_spec *spec);
400 static struct bus_attribute rbd_bus_attrs[] = {
401 __ATTR(add, S_IWUSR, NULL, rbd_add),
402 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
406 static struct bus_type rbd_bus_type = {
408 .bus_attrs = rbd_bus_attrs,
411 static void rbd_root_dev_release(struct device *dev)
415 static struct device rbd_root_dev = {
417 .release = rbd_root_dev_release,
420 static __printf(2, 3)
421 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
423 struct va_format vaf;
431 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
432 else if (rbd_dev->disk)
433 printk(KERN_WARNING "%s: %s: %pV\n",
434 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
435 else if (rbd_dev->spec && rbd_dev->spec->image_name)
436 printk(KERN_WARNING "%s: image %s: %pV\n",
437 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
438 else if (rbd_dev->spec && rbd_dev->spec->image_id)
439 printk(KERN_WARNING "%s: id %s: %pV\n",
440 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
442 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
443 RBD_DRV_NAME, rbd_dev, &vaf);
448 #define rbd_assert(expr) \
449 if (unlikely(!(expr))) { \
450 printk(KERN_ERR "\nAssertion failure in %s() " \
452 "\trbd_assert(%s);\n\n", \
453 __func__, __LINE__, #expr); \
456 #else /* !RBD_DEBUG */
457 # define rbd_assert(expr) ((void) 0)
458 #endif /* !RBD_DEBUG */
460 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
461 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
462 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
464 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
465 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
466 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev);
467 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
469 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
470 u8 *order, u64 *snap_size);
471 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
473 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name);
475 static int rbd_open(struct block_device *bdev, fmode_t mode)
477 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
478 bool removing = false;
480 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
483 spin_lock_irq(&rbd_dev->lock);
484 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
487 rbd_dev->open_count++;
488 spin_unlock_irq(&rbd_dev->lock);
492 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
493 (void) get_device(&rbd_dev->dev);
494 set_device_ro(bdev, rbd_dev->mapping.read_only);
495 mutex_unlock(&ctl_mutex);
500 static int rbd_release(struct gendisk *disk, fmode_t mode)
502 struct rbd_device *rbd_dev = disk->private_data;
503 unsigned long open_count_before;
505 spin_lock_irq(&rbd_dev->lock);
506 open_count_before = rbd_dev->open_count--;
507 spin_unlock_irq(&rbd_dev->lock);
508 rbd_assert(open_count_before > 0);
510 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
511 put_device(&rbd_dev->dev);
512 mutex_unlock(&ctl_mutex);
517 static const struct block_device_operations rbd_bd_ops = {
518 .owner = THIS_MODULE,
520 .release = rbd_release,
524 * Initialize an rbd client instance.
527 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
529 struct rbd_client *rbdc;
532 dout("%s:\n", __func__);
533 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
537 kref_init(&rbdc->kref);
538 INIT_LIST_HEAD(&rbdc->node);
540 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
542 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
543 if (IS_ERR(rbdc->client))
545 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
547 ret = ceph_open_session(rbdc->client);
551 spin_lock(&rbd_client_list_lock);
552 list_add_tail(&rbdc->node, &rbd_client_list);
553 spin_unlock(&rbd_client_list_lock);
555 mutex_unlock(&ctl_mutex);
556 dout("%s: rbdc %p\n", __func__, rbdc);
561 ceph_destroy_client(rbdc->client);
563 mutex_unlock(&ctl_mutex);
567 ceph_destroy_options(ceph_opts);
568 dout("%s: error %d\n", __func__, ret);
573 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
575 kref_get(&rbdc->kref);
581 * Find a ceph client with specific addr and configuration. If
582 * found, bump its reference count.
584 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
586 struct rbd_client *client_node;
589 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
592 spin_lock(&rbd_client_list_lock);
593 list_for_each_entry(client_node, &rbd_client_list, node) {
594 if (!ceph_compare_options(ceph_opts, client_node->client)) {
595 __rbd_get_client(client_node);
601 spin_unlock(&rbd_client_list_lock);
603 return found ? client_node : NULL;
613 /* string args above */
616 /* Boolean args above */
620 static match_table_t rbd_opts_tokens = {
622 /* string args above */
623 {Opt_read_only, "read_only"},
624 {Opt_read_only, "ro"}, /* Alternate spelling */
625 {Opt_read_write, "read_write"},
626 {Opt_read_write, "rw"}, /* Alternate spelling */
627 /* Boolean args above */
635 #define RBD_READ_ONLY_DEFAULT false
637 static int parse_rbd_opts_token(char *c, void *private)
639 struct rbd_options *rbd_opts = private;
640 substring_t argstr[MAX_OPT_ARGS];
641 int token, intval, ret;
643 token = match_token(c, rbd_opts_tokens, argstr);
647 if (token < Opt_last_int) {
648 ret = match_int(&argstr[0], &intval);
650 pr_err("bad mount option arg (not int) "
654 dout("got int token %d val %d\n", token, intval);
655 } else if (token > Opt_last_int && token < Opt_last_string) {
656 dout("got string token %d val %s\n", token,
658 } else if (token > Opt_last_string && token < Opt_last_bool) {
659 dout("got Boolean token %d\n", token);
661 dout("got token %d\n", token);
666 rbd_opts->read_only = true;
669 rbd_opts->read_only = false;
679 * Get a ceph client with specific addr and configuration, if one does
680 * not exist create it.
682 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
684 struct rbd_client *rbdc;
686 rbdc = rbd_client_find(ceph_opts);
687 if (rbdc) /* using an existing client */
688 ceph_destroy_options(ceph_opts);
690 rbdc = rbd_client_create(ceph_opts);
696 * Destroy ceph client
698 * Caller must hold rbd_client_list_lock.
700 static void rbd_client_release(struct kref *kref)
702 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
704 dout("%s: rbdc %p\n", __func__, rbdc);
705 spin_lock(&rbd_client_list_lock);
706 list_del(&rbdc->node);
707 spin_unlock(&rbd_client_list_lock);
709 ceph_destroy_client(rbdc->client);
714 * Drop reference to ceph client node. If it's not referenced anymore, release
717 static void rbd_put_client(struct rbd_client *rbdc)
720 kref_put(&rbdc->kref, rbd_client_release);
723 static bool rbd_image_format_valid(u32 image_format)
725 return image_format == 1 || image_format == 2;
728 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
733 /* The header has to start with the magic rbd header text */
734 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
737 /* The bio layer requires at least sector-sized I/O */
739 if (ondisk->options.order < SECTOR_SHIFT)
742 /* If we use u64 in a few spots we may be able to loosen this */
744 if (ondisk->options.order > 8 * sizeof (int) - 1)
748 * The size of a snapshot header has to fit in a size_t, and
749 * that limits the number of snapshots.
751 snap_count = le32_to_cpu(ondisk->snap_count);
752 size = SIZE_MAX - sizeof (struct ceph_snap_context);
753 if (snap_count > size / sizeof (__le64))
757 * Not only that, but the size of the entire the snapshot
758 * header must also be representable in a size_t.
760 size -= snap_count * sizeof (__le64);
761 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
768 * Fill an rbd image header with information from the given format 1
771 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
772 struct rbd_image_header_ondisk *ondisk)
774 struct rbd_image_header *header = &rbd_dev->header;
775 bool first_time = header->object_prefix == NULL;
776 struct ceph_snap_context *snapc;
777 char *object_prefix = NULL;
778 char *snap_names = NULL;
779 u64 *snap_sizes = NULL;
785 /* Allocate this now to avoid having to handle failure below */
790 len = strnlen(ondisk->object_prefix,
791 sizeof (ondisk->object_prefix));
792 object_prefix = kmalloc(len + 1, GFP_KERNEL);
795 memcpy(object_prefix, ondisk->object_prefix, len);
796 object_prefix[len] = '\0';
799 /* Allocate the snapshot context and fill it in */
801 snap_count = le32_to_cpu(ondisk->snap_count);
802 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
805 snapc->seq = le64_to_cpu(ondisk->snap_seq);
807 struct rbd_image_snap_ondisk *snaps;
808 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
810 /* We'll keep a copy of the snapshot names... */
812 if (snap_names_len > (u64)SIZE_MAX)
814 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
818 /* ...as well as the array of their sizes. */
820 size = snap_count * sizeof (*header->snap_sizes);
821 snap_sizes = kmalloc(size, GFP_KERNEL);
826 * Copy the names, and fill in each snapshot's id
829 * Note that rbd_dev_v1_header_info() guarantees the
830 * ondisk buffer we're working with has
831 * snap_names_len bytes beyond the end of the
832 * snapshot id array, this memcpy() is safe.
834 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
835 snaps = ondisk->snaps;
836 for (i = 0; i < snap_count; i++) {
837 snapc->snaps[i] = le64_to_cpu(snaps[i].id);
838 snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
842 /* We won't fail any more, fill in the header */
844 down_write(&rbd_dev->header_rwsem);
846 header->object_prefix = object_prefix;
847 header->obj_order = ondisk->options.order;
848 header->crypt_type = ondisk->options.crypt_type;
849 header->comp_type = ondisk->options.comp_type;
850 /* The rest aren't used for format 1 images */
851 header->stripe_unit = 0;
852 header->stripe_count = 0;
853 header->features = 0;
855 ceph_put_snap_context(header->snapc);
856 kfree(header->snap_names);
857 kfree(header->snap_sizes);
860 /* The remaining fields always get updated (when we refresh) */
862 header->image_size = le64_to_cpu(ondisk->image_size);
863 header->snapc = snapc;
864 header->snap_names = snap_names;
865 header->snap_sizes = snap_sizes;
867 /* Make sure mapping size is consistent with header info */
869 if (rbd_dev->spec->snap_id == CEPH_NOSNAP || first_time)
870 if (rbd_dev->mapping.size != header->image_size)
871 rbd_dev->mapping.size = header->image_size;
873 up_write(&rbd_dev->header_rwsem);
881 ceph_put_snap_context(snapc);
882 kfree(object_prefix);
887 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
889 const char *snap_name;
891 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
893 /* Skip over names until we find the one we are looking for */
895 snap_name = rbd_dev->header.snap_names;
897 snap_name += strlen(snap_name) + 1;
899 return kstrdup(snap_name, GFP_KERNEL);
903 * Snapshot id comparison function for use with qsort()/bsearch().
904 * Note that result is for snapshots in *descending* order.
906 static int snapid_compare_reverse(const void *s1, const void *s2)
908 u64 snap_id1 = *(u64 *)s1;
909 u64 snap_id2 = *(u64 *)s2;
911 if (snap_id1 < snap_id2)
913 return snap_id1 == snap_id2 ? 0 : -1;
917 * Search a snapshot context to see if the given snapshot id is
920 * Returns the position of the snapshot id in the array if it's found,
921 * or BAD_SNAP_INDEX otherwise.
923 * Note: The snapshot array is in kept sorted (by the osd) in
924 * reverse order, highest snapshot id first.
926 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
928 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
931 found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
932 sizeof (snap_id), snapid_compare_reverse);
934 return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
937 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
942 which = rbd_dev_snap_index(rbd_dev, snap_id);
943 if (which == BAD_SNAP_INDEX)
946 return _rbd_dev_v1_snap_name(rbd_dev, which);
949 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
951 if (snap_id == CEPH_NOSNAP)
952 return RBD_SNAP_HEAD_NAME;
954 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
955 if (rbd_dev->image_format == 1)
956 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
958 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
961 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
964 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
965 if (snap_id == CEPH_NOSNAP) {
966 *snap_size = rbd_dev->header.image_size;
967 } else if (rbd_dev->image_format == 1) {
970 which = rbd_dev_snap_index(rbd_dev, snap_id);
971 if (which == BAD_SNAP_INDEX)
974 *snap_size = rbd_dev->header.snap_sizes[which];
979 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
988 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
991 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
992 if (snap_id == CEPH_NOSNAP) {
993 *snap_features = rbd_dev->header.features;
994 } else if (rbd_dev->image_format == 1) {
995 *snap_features = 0; /* No features for format 1 */
1000 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
1004 *snap_features = features;
1009 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
1011 u64 snap_id = rbd_dev->spec->snap_id;
1016 ret = rbd_snap_size(rbd_dev, snap_id, &size);
1019 ret = rbd_snap_features(rbd_dev, snap_id, &features);
1023 rbd_dev->mapping.size = size;
1024 rbd_dev->mapping.features = features;
1029 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
1031 rbd_dev->mapping.size = 0;
1032 rbd_dev->mapping.features = 0;
1035 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1041 name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
1044 segment = offset >> rbd_dev->header.obj_order;
1045 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
1046 rbd_dev->header.object_prefix, segment);
1047 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
1048 pr_err("error formatting segment name for #%llu (%d)\n",
1057 static void rbd_segment_name_free(const char *name)
1059 /* The explicit cast here is needed to drop the const qualifier */
1061 kmem_cache_free(rbd_segment_name_cache, (void *)name);
1064 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1066 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1068 return offset & (segment_size - 1);
1071 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1072 u64 offset, u64 length)
1074 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1076 offset &= segment_size - 1;
1078 rbd_assert(length <= U64_MAX - offset);
1079 if (offset + length > segment_size)
1080 length = segment_size - offset;
1086 * returns the size of an object in the image
1088 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1090 return 1 << header->obj_order;
1097 static void bio_chain_put(struct bio *chain)
1103 chain = chain->bi_next;
1109 * zeros a bio chain, starting at specific offset
1111 static void zero_bio_chain(struct bio *chain, int start_ofs)
1114 unsigned long flags;
1120 bio_for_each_segment(bv, chain, i) {
1121 if (pos + bv->bv_len > start_ofs) {
1122 int remainder = max(start_ofs - pos, 0);
1123 buf = bvec_kmap_irq(bv, &flags);
1124 memset(buf + remainder, 0,
1125 bv->bv_len - remainder);
1126 bvec_kunmap_irq(buf, &flags);
1131 chain = chain->bi_next;
1136 * similar to zero_bio_chain(), zeros data defined by a page array,
1137 * starting at the given byte offset from the start of the array and
1138 * continuing up to the given end offset. The pages array is
1139 * assumed to be big enough to hold all bytes up to the end.
1141 static void zero_pages(struct page **pages, u64 offset, u64 end)
1143 struct page **page = &pages[offset >> PAGE_SHIFT];
1145 rbd_assert(end > offset);
1146 rbd_assert(end - offset <= (u64)SIZE_MAX);
1147 while (offset < end) {
1150 unsigned long flags;
1153 page_offset = (size_t)(offset & ~PAGE_MASK);
1154 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1155 local_irq_save(flags);
1156 kaddr = kmap_atomic(*page);
1157 memset(kaddr + page_offset, 0, length);
1158 kunmap_atomic(kaddr);
1159 local_irq_restore(flags);
1167 * Clone a portion of a bio, starting at the given byte offset
1168 * and continuing for the number of bytes indicated.
1170 static struct bio *bio_clone_range(struct bio *bio_src,
1171 unsigned int offset,
1179 unsigned short end_idx;
1180 unsigned short vcnt;
1183 /* Handle the easy case for the caller */
1185 if (!offset && len == bio_src->bi_size)
1186 return bio_clone(bio_src, gfpmask);
1188 if (WARN_ON_ONCE(!len))
1190 if (WARN_ON_ONCE(len > bio_src->bi_size))
1192 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1195 /* Find first affected segment... */
1198 __bio_for_each_segment(bv, bio_src, idx, 0) {
1199 if (resid < bv->bv_len)
1201 resid -= bv->bv_len;
1205 /* ...and the last affected segment */
1208 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1209 if (resid <= bv->bv_len)
1211 resid -= bv->bv_len;
1213 vcnt = end_idx - idx + 1;
1215 /* Build the clone */
1217 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1219 return NULL; /* ENOMEM */
1221 bio->bi_bdev = bio_src->bi_bdev;
1222 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1223 bio->bi_rw = bio_src->bi_rw;
1224 bio->bi_flags |= 1 << BIO_CLONED;
1227 * Copy over our part of the bio_vec, then update the first
1228 * and last (or only) entries.
1230 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1231 vcnt * sizeof (struct bio_vec));
1232 bio->bi_io_vec[0].bv_offset += voff;
1234 bio->bi_io_vec[0].bv_len -= voff;
1235 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1237 bio->bi_io_vec[0].bv_len = len;
1240 bio->bi_vcnt = vcnt;
1248 * Clone a portion of a bio chain, starting at the given byte offset
1249 * into the first bio in the source chain and continuing for the
1250 * number of bytes indicated. The result is another bio chain of
1251 * exactly the given length, or a null pointer on error.
1253 * The bio_src and offset parameters are both in-out. On entry they
1254 * refer to the first source bio and the offset into that bio where
1255 * the start of data to be cloned is located.
1257 * On return, bio_src is updated to refer to the bio in the source
1258 * chain that contains first un-cloned byte, and *offset will
1259 * contain the offset of that byte within that bio.
1261 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1262 unsigned int *offset,
1266 struct bio *bi = *bio_src;
1267 unsigned int off = *offset;
1268 struct bio *chain = NULL;
1271 /* Build up a chain of clone bios up to the limit */
1273 if (!bi || off >= bi->bi_size || !len)
1274 return NULL; /* Nothing to clone */
1278 unsigned int bi_size;
1282 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1283 goto out_err; /* EINVAL; ran out of bio's */
1285 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1286 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1288 goto out_err; /* ENOMEM */
1291 end = &bio->bi_next;
1294 if (off == bi->bi_size) {
1305 bio_chain_put(chain);
1311 * The default/initial value for all object request flags is 0. For
1312 * each flag, once its value is set to 1 it is never reset to 0
1315 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1317 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1318 struct rbd_device *rbd_dev;
1320 rbd_dev = obj_request->img_request->rbd_dev;
1321 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1326 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1329 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1332 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1334 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1335 struct rbd_device *rbd_dev = NULL;
1337 if (obj_request_img_data_test(obj_request))
1338 rbd_dev = obj_request->img_request->rbd_dev;
1339 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1344 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1347 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1351 * This sets the KNOWN flag after (possibly) setting the EXISTS
1352 * flag. The latter is set based on the "exists" value provided.
1354 * Note that for our purposes once an object exists it never goes
1355 * away again. It's possible that the response from two existence
1356 * checks are separated by the creation of the target object, and
1357 * the first ("doesn't exist") response arrives *after* the second
1358 * ("does exist"). In that case we ignore the second one.
1360 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1364 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1365 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1369 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1372 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1375 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1378 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1381 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1383 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1384 atomic_read(&obj_request->kref.refcount));
1385 kref_get(&obj_request->kref);
1388 static void rbd_obj_request_destroy(struct kref *kref);
1389 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1391 rbd_assert(obj_request != NULL);
1392 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1393 atomic_read(&obj_request->kref.refcount));
1394 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1397 static bool img_request_child_test(struct rbd_img_request *img_request);
1398 static void rbd_parent_request_destroy(struct kref *kref);
1399 static void rbd_img_request_destroy(struct kref *kref);
1400 static void rbd_img_request_put(struct rbd_img_request *img_request)
1402 rbd_assert(img_request != NULL);
1403 dout("%s: img %p (was %d)\n", __func__, img_request,
1404 atomic_read(&img_request->kref.refcount));
1405 if (img_request_child_test(img_request))
1406 kref_put(&img_request->kref, rbd_parent_request_destroy);
1408 kref_put(&img_request->kref, rbd_img_request_destroy);
1411 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1412 struct rbd_obj_request *obj_request)
1414 rbd_assert(obj_request->img_request == NULL);
1416 /* Image request now owns object's original reference */
1417 obj_request->img_request = img_request;
1418 obj_request->which = img_request->obj_request_count;
1419 rbd_assert(!obj_request_img_data_test(obj_request));
1420 obj_request_img_data_set(obj_request);
1421 rbd_assert(obj_request->which != BAD_WHICH);
1422 img_request->obj_request_count++;
1423 list_add_tail(&obj_request->links, &img_request->obj_requests);
1424 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1425 obj_request->which);
1428 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1429 struct rbd_obj_request *obj_request)
1431 rbd_assert(obj_request->which != BAD_WHICH);
1433 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1434 obj_request->which);
1435 list_del(&obj_request->links);
1436 rbd_assert(img_request->obj_request_count > 0);
1437 img_request->obj_request_count--;
1438 rbd_assert(obj_request->which == img_request->obj_request_count);
1439 obj_request->which = BAD_WHICH;
1440 rbd_assert(obj_request_img_data_test(obj_request));
1441 rbd_assert(obj_request->img_request == img_request);
1442 obj_request->img_request = NULL;
1443 obj_request->callback = NULL;
1444 rbd_obj_request_put(obj_request);
1447 static bool obj_request_type_valid(enum obj_request_type type)
1450 case OBJ_REQUEST_NODATA:
1451 case OBJ_REQUEST_BIO:
1452 case OBJ_REQUEST_PAGES:
1459 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1460 struct rbd_obj_request *obj_request)
1462 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1464 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1467 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1470 dout("%s: img %p\n", __func__, img_request);
1473 * If no error occurred, compute the aggregate transfer
1474 * count for the image request. We could instead use
1475 * atomic64_cmpxchg() to update it as each object request
1476 * completes; not clear which way is better off hand.
1478 if (!img_request->result) {
1479 struct rbd_obj_request *obj_request;
1482 for_each_obj_request(img_request, obj_request)
1483 xferred += obj_request->xferred;
1484 img_request->xferred = xferred;
1487 if (img_request->callback)
1488 img_request->callback(img_request);
1490 rbd_img_request_put(img_request);
1493 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1495 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1497 dout("%s: obj %p\n", __func__, obj_request);
1499 return wait_for_completion_interruptible(&obj_request->completion);
1503 * The default/initial value for all image request flags is 0. Each
1504 * is conditionally set to 1 at image request initialization time
1505 * and currently never change thereafter.
1507 static void img_request_write_set(struct rbd_img_request *img_request)
1509 set_bit(IMG_REQ_WRITE, &img_request->flags);
1513 static bool img_request_write_test(struct rbd_img_request *img_request)
1516 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1519 static void img_request_child_set(struct rbd_img_request *img_request)
1521 set_bit(IMG_REQ_CHILD, &img_request->flags);
1525 static void img_request_child_clear(struct rbd_img_request *img_request)
1527 clear_bit(IMG_REQ_CHILD, &img_request->flags);
1531 static bool img_request_child_test(struct rbd_img_request *img_request)
1534 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1537 static void img_request_layered_set(struct rbd_img_request *img_request)
1539 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1543 static void img_request_layered_clear(struct rbd_img_request *img_request)
1545 clear_bit(IMG_REQ_LAYERED, &img_request->flags);
1549 static bool img_request_layered_test(struct rbd_img_request *img_request)
1552 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1556 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1558 u64 xferred = obj_request->xferred;
1559 u64 length = obj_request->length;
1561 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1562 obj_request, obj_request->img_request, obj_request->result,
1565 * ENOENT means a hole in the image. We zero-fill the
1566 * entire length of the request. A short read also implies
1567 * zero-fill to the end of the request. Either way we
1568 * update the xferred count to indicate the whole request
1571 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1572 if (obj_request->result == -ENOENT) {
1573 if (obj_request->type == OBJ_REQUEST_BIO)
1574 zero_bio_chain(obj_request->bio_list, 0);
1576 zero_pages(obj_request->pages, 0, length);
1577 obj_request->result = 0;
1578 obj_request->xferred = length;
1579 } else if (xferred < length && !obj_request->result) {
1580 if (obj_request->type == OBJ_REQUEST_BIO)
1581 zero_bio_chain(obj_request->bio_list, xferred);
1583 zero_pages(obj_request->pages, xferred, length);
1584 obj_request->xferred = length;
1586 obj_request_done_set(obj_request);
1589 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1591 dout("%s: obj %p cb %p\n", __func__, obj_request,
1592 obj_request->callback);
1593 if (obj_request->callback)
1594 obj_request->callback(obj_request);
1596 complete_all(&obj_request->completion);
1599 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1601 dout("%s: obj %p\n", __func__, obj_request);
1602 obj_request_done_set(obj_request);
1605 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1607 struct rbd_img_request *img_request = NULL;
1608 struct rbd_device *rbd_dev = NULL;
1609 bool layered = false;
1611 if (obj_request_img_data_test(obj_request)) {
1612 img_request = obj_request->img_request;
1613 layered = img_request && img_request_layered_test(img_request);
1614 rbd_dev = img_request->rbd_dev;
1617 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1618 obj_request, img_request, obj_request->result,
1619 obj_request->xferred, obj_request->length);
1620 if (layered && obj_request->result == -ENOENT &&
1621 obj_request->img_offset < rbd_dev->parent_overlap)
1622 rbd_img_parent_read(obj_request);
1623 else if (img_request)
1624 rbd_img_obj_request_read_callback(obj_request);
1626 obj_request_done_set(obj_request);
1629 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1631 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1632 obj_request->result, obj_request->length);
1634 * There is no such thing as a successful short write. Set
1635 * it to our originally-requested length.
1637 obj_request->xferred = obj_request->length;
1638 obj_request_done_set(obj_request);
1642 * For a simple stat call there's nothing to do. We'll do more if
1643 * this is part of a write sequence for a layered image.
1645 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1647 dout("%s: obj %p\n", __func__, obj_request);
1648 obj_request_done_set(obj_request);
1651 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1652 struct ceph_msg *msg)
1654 struct rbd_obj_request *obj_request = osd_req->r_priv;
1657 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1658 rbd_assert(osd_req == obj_request->osd_req);
1659 if (obj_request_img_data_test(obj_request)) {
1660 rbd_assert(obj_request->img_request);
1661 rbd_assert(obj_request->which != BAD_WHICH);
1663 rbd_assert(obj_request->which == BAD_WHICH);
1666 if (osd_req->r_result < 0)
1667 obj_request->result = osd_req->r_result;
1669 BUG_ON(osd_req->r_num_ops > 2);
1672 * We support a 64-bit length, but ultimately it has to be
1673 * passed to blk_end_request(), which takes an unsigned int.
1675 obj_request->xferred = osd_req->r_reply_op_len[0];
1676 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1677 opcode = osd_req->r_ops[0].op;
1679 case CEPH_OSD_OP_READ:
1680 rbd_osd_read_callback(obj_request);
1682 case CEPH_OSD_OP_WRITE:
1683 rbd_osd_write_callback(obj_request);
1685 case CEPH_OSD_OP_STAT:
1686 rbd_osd_stat_callback(obj_request);
1688 case CEPH_OSD_OP_CALL:
1689 case CEPH_OSD_OP_NOTIFY_ACK:
1690 case CEPH_OSD_OP_WATCH:
1691 rbd_osd_trivial_callback(obj_request);
1694 rbd_warn(NULL, "%s: unsupported op %hu\n",
1695 obj_request->object_name, (unsigned short) opcode);
1699 if (obj_request_done_test(obj_request))
1700 rbd_obj_request_complete(obj_request);
1703 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1705 struct rbd_img_request *img_request = obj_request->img_request;
1706 struct ceph_osd_request *osd_req = obj_request->osd_req;
1709 rbd_assert(osd_req != NULL);
1711 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1712 ceph_osdc_build_request(osd_req, obj_request->offset,
1713 NULL, snap_id, NULL);
1716 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1718 struct rbd_img_request *img_request = obj_request->img_request;
1719 struct ceph_osd_request *osd_req = obj_request->osd_req;
1720 struct ceph_snap_context *snapc;
1721 struct timespec mtime = CURRENT_TIME;
1723 rbd_assert(osd_req != NULL);
1725 snapc = img_request ? img_request->snapc : NULL;
1726 ceph_osdc_build_request(osd_req, obj_request->offset,
1727 snapc, CEPH_NOSNAP, &mtime);
1730 static struct ceph_osd_request *rbd_osd_req_create(
1731 struct rbd_device *rbd_dev,
1733 struct rbd_obj_request *obj_request)
1735 struct ceph_snap_context *snapc = NULL;
1736 struct ceph_osd_client *osdc;
1737 struct ceph_osd_request *osd_req;
1739 if (obj_request_img_data_test(obj_request)) {
1740 struct rbd_img_request *img_request = obj_request->img_request;
1742 rbd_assert(write_request ==
1743 img_request_write_test(img_request));
1745 snapc = img_request->snapc;
1748 /* Allocate and initialize the request, for the single op */
1750 osdc = &rbd_dev->rbd_client->client->osdc;
1751 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1753 return NULL; /* ENOMEM */
1756 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1758 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1760 osd_req->r_callback = rbd_osd_req_callback;
1761 osd_req->r_priv = obj_request;
1763 osd_req->r_oid_len = strlen(obj_request->object_name);
1764 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1765 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1767 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1773 * Create a copyup osd request based on the information in the
1774 * object request supplied. A copyup request has two osd ops,
1775 * a copyup method call, and a "normal" write request.
1777 static struct ceph_osd_request *
1778 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1780 struct rbd_img_request *img_request;
1781 struct ceph_snap_context *snapc;
1782 struct rbd_device *rbd_dev;
1783 struct ceph_osd_client *osdc;
1784 struct ceph_osd_request *osd_req;
1786 rbd_assert(obj_request_img_data_test(obj_request));
1787 img_request = obj_request->img_request;
1788 rbd_assert(img_request);
1789 rbd_assert(img_request_write_test(img_request));
1791 /* Allocate and initialize the request, for the two ops */
1793 snapc = img_request->snapc;
1794 rbd_dev = img_request->rbd_dev;
1795 osdc = &rbd_dev->rbd_client->client->osdc;
1796 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1798 return NULL; /* ENOMEM */
1800 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1801 osd_req->r_callback = rbd_osd_req_callback;
1802 osd_req->r_priv = obj_request;
1804 osd_req->r_oid_len = strlen(obj_request->object_name);
1805 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1806 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1808 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1814 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1816 ceph_osdc_put_request(osd_req);
1819 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1821 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1822 u64 offset, u64 length,
1823 enum obj_request_type type)
1825 struct rbd_obj_request *obj_request;
1829 rbd_assert(obj_request_type_valid(type));
1831 size = strlen(object_name) + 1;
1832 name = kmalloc(size, GFP_KERNEL);
1836 obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
1842 obj_request->object_name = memcpy(name, object_name, size);
1843 obj_request->offset = offset;
1844 obj_request->length = length;
1845 obj_request->flags = 0;
1846 obj_request->which = BAD_WHICH;
1847 obj_request->type = type;
1848 INIT_LIST_HEAD(&obj_request->links);
1849 init_completion(&obj_request->completion);
1850 kref_init(&obj_request->kref);
1852 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1853 offset, length, (int)type, obj_request);
1858 static void rbd_obj_request_destroy(struct kref *kref)
1860 struct rbd_obj_request *obj_request;
1862 obj_request = container_of(kref, struct rbd_obj_request, kref);
1864 dout("%s: obj %p\n", __func__, obj_request);
1866 rbd_assert(obj_request->img_request == NULL);
1867 rbd_assert(obj_request->which == BAD_WHICH);
1869 if (obj_request->osd_req)
1870 rbd_osd_req_destroy(obj_request->osd_req);
1872 rbd_assert(obj_request_type_valid(obj_request->type));
1873 switch (obj_request->type) {
1874 case OBJ_REQUEST_NODATA:
1875 break; /* Nothing to do */
1876 case OBJ_REQUEST_BIO:
1877 if (obj_request->bio_list)
1878 bio_chain_put(obj_request->bio_list);
1880 case OBJ_REQUEST_PAGES:
1881 if (obj_request->pages)
1882 ceph_release_page_vector(obj_request->pages,
1883 obj_request->page_count);
1887 kfree(obj_request->object_name);
1888 obj_request->object_name = NULL;
1889 kmem_cache_free(rbd_obj_request_cache, obj_request);
1892 /* It's OK to call this for a device with no parent */
1894 static void rbd_spec_put(struct rbd_spec *spec);
1895 static void rbd_dev_unparent(struct rbd_device *rbd_dev)
1897 rbd_dev_remove_parent(rbd_dev);
1898 rbd_spec_put(rbd_dev->parent_spec);
1899 rbd_dev->parent_spec = NULL;
1900 rbd_dev->parent_overlap = 0;
1904 * Parent image reference counting is used to determine when an
1905 * image's parent fields can be safely torn down--after there are no
1906 * more in-flight requests to the parent image. When the last
1907 * reference is dropped, cleaning them up is safe.
1909 static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
1913 if (!rbd_dev->parent_spec)
1916 counter = atomic_dec_return_safe(&rbd_dev->parent_ref);
1920 /* Last reference; clean up parent data structures */
1923 rbd_dev_unparent(rbd_dev);
1925 rbd_warn(rbd_dev, "parent reference underflow\n");
1929 * If an image has a non-zero parent overlap, get a reference to its
1932 * We must get the reference before checking for the overlap to
1933 * coordinate properly with zeroing the parent overlap in
1934 * rbd_dev_v2_parent_info() when an image gets flattened. We
1935 * drop it again if there is no overlap.
1937 * Returns true if the rbd device has a parent with a non-zero
1938 * overlap and a reference for it was successfully taken, or
1941 static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
1945 if (!rbd_dev->parent_spec)
1948 counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
1949 if (counter > 0 && rbd_dev->parent_overlap)
1952 /* Image was flattened, but parent is not yet torn down */
1955 rbd_warn(rbd_dev, "parent reference overflow\n");
1961 * Caller is responsible for filling in the list of object requests
1962 * that comprises the image request, and the Linux request pointer
1963 * (if there is one).
1965 static struct rbd_img_request *rbd_img_request_create(
1966 struct rbd_device *rbd_dev,
1967 u64 offset, u64 length,
1970 struct rbd_img_request *img_request;
1972 img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_ATOMIC);
1976 if (write_request) {
1977 down_read(&rbd_dev->header_rwsem);
1978 ceph_get_snap_context(rbd_dev->header.snapc);
1979 up_read(&rbd_dev->header_rwsem);
1982 img_request->rq = NULL;
1983 img_request->rbd_dev = rbd_dev;
1984 img_request->offset = offset;
1985 img_request->length = length;
1986 img_request->flags = 0;
1987 if (write_request) {
1988 img_request_write_set(img_request);
1989 img_request->snapc = rbd_dev->header.snapc;
1991 img_request->snap_id = rbd_dev->spec->snap_id;
1993 if (rbd_dev_parent_get(rbd_dev))
1994 img_request_layered_set(img_request);
1995 spin_lock_init(&img_request->completion_lock);
1996 img_request->next_completion = 0;
1997 img_request->callback = NULL;
1998 img_request->result = 0;
1999 img_request->obj_request_count = 0;
2000 INIT_LIST_HEAD(&img_request->obj_requests);
2001 kref_init(&img_request->kref);
2003 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
2004 write_request ? "write" : "read", offset, length,
2010 static void rbd_img_request_destroy(struct kref *kref)
2012 struct rbd_img_request *img_request;
2013 struct rbd_obj_request *obj_request;
2014 struct rbd_obj_request *next_obj_request;
2016 img_request = container_of(kref, struct rbd_img_request, kref);
2018 dout("%s: img %p\n", __func__, img_request);
2020 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2021 rbd_img_obj_request_del(img_request, obj_request);
2022 rbd_assert(img_request->obj_request_count == 0);
2024 if (img_request_layered_test(img_request)) {
2025 img_request_layered_clear(img_request);
2026 rbd_dev_parent_put(img_request->rbd_dev);
2029 if (img_request_write_test(img_request))
2030 ceph_put_snap_context(img_request->snapc);
2032 kmem_cache_free(rbd_img_request_cache, img_request);
2035 static struct rbd_img_request *rbd_parent_request_create(
2036 struct rbd_obj_request *obj_request,
2037 u64 img_offset, u64 length)
2039 struct rbd_img_request *parent_request;
2040 struct rbd_device *rbd_dev;
2042 rbd_assert(obj_request->img_request);
2043 rbd_dev = obj_request->img_request->rbd_dev;
2045 parent_request = rbd_img_request_create(rbd_dev->parent,
2046 img_offset, length, false);
2047 if (!parent_request)
2050 img_request_child_set(parent_request);
2051 rbd_obj_request_get(obj_request);
2052 parent_request->obj_request = obj_request;
2054 return parent_request;
2057 static void rbd_parent_request_destroy(struct kref *kref)
2059 struct rbd_img_request *parent_request;
2060 struct rbd_obj_request *orig_request;
2062 parent_request = container_of(kref, struct rbd_img_request, kref);
2063 orig_request = parent_request->obj_request;
2065 parent_request->obj_request = NULL;
2066 rbd_obj_request_put(orig_request);
2067 img_request_child_clear(parent_request);
2069 rbd_img_request_destroy(kref);
2072 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
2074 struct rbd_img_request *img_request;
2075 unsigned int xferred;
2079 rbd_assert(obj_request_img_data_test(obj_request));
2080 img_request = obj_request->img_request;
2082 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
2083 xferred = (unsigned int)obj_request->xferred;
2084 result = obj_request->result;
2086 struct rbd_device *rbd_dev = img_request->rbd_dev;
2088 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
2089 img_request_write_test(img_request) ? "write" : "read",
2090 obj_request->length, obj_request->img_offset,
2091 obj_request->offset);
2092 rbd_warn(rbd_dev, " result %d xferred %x\n",
2094 if (!img_request->result)
2095 img_request->result = result;
2098 /* Image object requests don't own their page array */
2100 if (obj_request->type == OBJ_REQUEST_PAGES) {
2101 obj_request->pages = NULL;
2102 obj_request->page_count = 0;
2105 if (img_request_child_test(img_request)) {
2106 rbd_assert(img_request->obj_request != NULL);
2107 more = obj_request->which < img_request->obj_request_count - 1;
2109 rbd_assert(img_request->rq != NULL);
2110 more = blk_end_request(img_request->rq, result, xferred);
2116 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
2118 struct rbd_img_request *img_request;
2119 u32 which = obj_request->which;
2122 rbd_assert(obj_request_img_data_test(obj_request));
2123 img_request = obj_request->img_request;
2125 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
2126 rbd_assert(img_request != NULL);
2127 rbd_assert(img_request->obj_request_count > 0);
2128 rbd_assert(which != BAD_WHICH);
2129 rbd_assert(which < img_request->obj_request_count);
2130 rbd_assert(which >= img_request->next_completion);
2132 spin_lock_irq(&img_request->completion_lock);
2133 if (which != img_request->next_completion)
2136 for_each_obj_request_from(img_request, obj_request) {
2138 rbd_assert(which < img_request->obj_request_count);
2140 if (!obj_request_done_test(obj_request))
2142 more = rbd_img_obj_end_request(obj_request);
2146 rbd_assert(more ^ (which == img_request->obj_request_count));
2147 img_request->next_completion = which;
2149 spin_unlock_irq(&img_request->completion_lock);
2152 rbd_img_request_complete(img_request);
2156 * Split up an image request into one or more object requests, each
2157 * to a different object. The "type" parameter indicates whether
2158 * "data_desc" is the pointer to the head of a list of bio
2159 * structures, or the base of a page array. In either case this
2160 * function assumes data_desc describes memory sufficient to hold
2161 * all data described by the image request.
2163 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2164 enum obj_request_type type,
2167 struct rbd_device *rbd_dev = img_request->rbd_dev;
2168 struct rbd_obj_request *obj_request = NULL;
2169 struct rbd_obj_request *next_obj_request;
2170 bool write_request = img_request_write_test(img_request);
2171 struct bio *bio_list;
2172 unsigned int bio_offset = 0;
2173 struct page **pages;
2178 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2179 (int)type, data_desc);
2181 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
2182 img_offset = img_request->offset;
2183 resid = img_request->length;
2184 rbd_assert(resid > 0);
2186 if (type == OBJ_REQUEST_BIO) {
2187 bio_list = data_desc;
2188 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
2190 rbd_assert(type == OBJ_REQUEST_PAGES);
2195 struct ceph_osd_request *osd_req;
2196 const char *object_name;
2200 object_name = rbd_segment_name(rbd_dev, img_offset);
2203 offset = rbd_segment_offset(rbd_dev, img_offset);
2204 length = rbd_segment_length(rbd_dev, img_offset, resid);
2205 obj_request = rbd_obj_request_create(object_name,
2206 offset, length, type);
2207 /* object request has its own copy of the object name */
2208 rbd_segment_name_free(object_name);
2212 if (type == OBJ_REQUEST_BIO) {
2213 unsigned int clone_size;
2215 rbd_assert(length <= (u64)UINT_MAX);
2216 clone_size = (unsigned int)length;
2217 obj_request->bio_list =
2218 bio_chain_clone_range(&bio_list,
2222 if (!obj_request->bio_list)
2225 unsigned int page_count;
2227 obj_request->pages = pages;
2228 page_count = (u32)calc_pages_for(offset, length);
2229 obj_request->page_count = page_count;
2230 if ((offset + length) & ~PAGE_MASK)
2231 page_count--; /* more on last page */
2232 pages += page_count;
2235 osd_req = rbd_osd_req_create(rbd_dev, write_request,
2239 obj_request->osd_req = osd_req;
2240 obj_request->callback = rbd_img_obj_callback;
2242 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
2244 if (type == OBJ_REQUEST_BIO)
2245 osd_req_op_extent_osd_data_bio(osd_req, 0,
2246 obj_request->bio_list, length);
2248 osd_req_op_extent_osd_data_pages(osd_req, 0,
2249 obj_request->pages, length,
2250 offset & ~PAGE_MASK, false, false);
2253 rbd_osd_req_format_write(obj_request);
2255 rbd_osd_req_format_read(obj_request);
2257 obj_request->img_offset = img_offset;
2258 rbd_img_obj_request_add(img_request, obj_request);
2260 img_offset += length;
2267 rbd_obj_request_put(obj_request);
2269 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2270 rbd_obj_request_put(obj_request);
2276 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2278 struct rbd_img_request *img_request;
2279 struct rbd_device *rbd_dev;
2280 struct page **pages;
2283 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2284 rbd_assert(obj_request_img_data_test(obj_request));
2285 img_request = obj_request->img_request;
2286 rbd_assert(img_request);
2288 rbd_dev = img_request->rbd_dev;
2289 rbd_assert(rbd_dev);
2291 pages = obj_request->copyup_pages;
2292 rbd_assert(pages != NULL);
2293 obj_request->copyup_pages = NULL;
2294 page_count = obj_request->copyup_page_count;
2295 rbd_assert(page_count);
2296 obj_request->copyup_page_count = 0;
2297 ceph_release_page_vector(pages, page_count);
2300 * We want the transfer count to reflect the size of the
2301 * original write request. There is no such thing as a
2302 * successful short write, so if the request was successful
2303 * we can just set it to the originally-requested length.
2305 if (!obj_request->result)
2306 obj_request->xferred = obj_request->length;
2308 /* Finish up with the normal image object callback */
2310 rbd_img_obj_callback(obj_request);
2314 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2316 struct rbd_obj_request *orig_request;
2317 struct ceph_osd_request *osd_req;
2318 struct ceph_osd_client *osdc;
2319 struct rbd_device *rbd_dev;
2320 struct page **pages;
2327 rbd_assert(img_request_child_test(img_request));
2329 /* First get what we need from the image request */
2331 pages = img_request->copyup_pages;
2332 rbd_assert(pages != NULL);
2333 img_request->copyup_pages = NULL;
2334 page_count = img_request->copyup_page_count;
2335 rbd_assert(page_count);
2336 img_request->copyup_page_count = 0;
2338 orig_request = img_request->obj_request;
2339 rbd_assert(orig_request != NULL);
2340 rbd_assert(obj_request_type_valid(orig_request->type));
2341 img_result = img_request->result;
2342 parent_length = img_request->length;
2343 rbd_assert(parent_length == img_request->xferred);
2344 rbd_img_request_put(img_request);
2346 rbd_assert(orig_request->img_request);
2347 rbd_dev = orig_request->img_request->rbd_dev;
2348 rbd_assert(rbd_dev);
2351 * If the overlap has become 0 (most likely because the
2352 * image has been flattened) we need to free the pages
2353 * and re-submit the original write request.
2355 if (!rbd_dev->parent_overlap) {
2356 struct ceph_osd_client *osdc;
2358 ceph_release_page_vector(pages, page_count);
2359 osdc = &rbd_dev->rbd_client->client->osdc;
2360 img_result = rbd_obj_request_submit(osdc, orig_request);
2369 * The original osd request is of no use to use any more.
2370 * We need a new one that can hold the two ops in a copyup
2371 * request. Allocate the new copyup osd request for the
2372 * original request, and release the old one.
2374 img_result = -ENOMEM;
2375 osd_req = rbd_osd_req_create_copyup(orig_request);
2378 rbd_osd_req_destroy(orig_request->osd_req);
2379 orig_request->osd_req = osd_req;
2380 orig_request->copyup_pages = pages;
2381 orig_request->copyup_page_count = page_count;
2383 /* Initialize the copyup op */
2385 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2386 osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2389 /* Then the original write request op */
2391 offset = orig_request->offset;
2392 length = orig_request->length;
2393 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2394 offset, length, 0, 0);
2395 if (orig_request->type == OBJ_REQUEST_BIO)
2396 osd_req_op_extent_osd_data_bio(osd_req, 1,
2397 orig_request->bio_list, length);
2399 osd_req_op_extent_osd_data_pages(osd_req, 1,
2400 orig_request->pages, length,
2401 offset & ~PAGE_MASK, false, false);
2403 rbd_osd_req_format_write(orig_request);
2405 /* All set, send it off. */
2407 orig_request->callback = rbd_img_obj_copyup_callback;
2408 osdc = &rbd_dev->rbd_client->client->osdc;
2409 img_result = rbd_obj_request_submit(osdc, orig_request);
2413 /* Record the error code and complete the request */
2415 orig_request->result = img_result;
2416 orig_request->xferred = 0;
2417 obj_request_done_set(orig_request);
2418 rbd_obj_request_complete(orig_request);
2422 * Read from the parent image the range of data that covers the
2423 * entire target of the given object request. This is used for
2424 * satisfying a layered image write request when the target of an
2425 * object request from the image request does not exist.
2427 * A page array big enough to hold the returned data is allocated
2428 * and supplied to rbd_img_request_fill() as the "data descriptor."
2429 * When the read completes, this page array will be transferred to
2430 * the original object request for the copyup operation.
2432 * If an error occurs, record it as the result of the original
2433 * object request and mark it done so it gets completed.
2435 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2437 struct rbd_img_request *img_request = NULL;
2438 struct rbd_img_request *parent_request = NULL;
2439 struct rbd_device *rbd_dev;
2442 struct page **pages = NULL;
2446 rbd_assert(obj_request_img_data_test(obj_request));
2447 rbd_assert(obj_request_type_valid(obj_request->type));
2449 img_request = obj_request->img_request;
2450 rbd_assert(img_request != NULL);
2451 rbd_dev = img_request->rbd_dev;
2452 rbd_assert(rbd_dev->parent != NULL);
2455 * Determine the byte range covered by the object in the
2456 * child image to which the original request was to be sent.
2458 img_offset = obj_request->img_offset - obj_request->offset;
2459 length = (u64)1 << rbd_dev->header.obj_order;
2462 * There is no defined parent data beyond the parent
2463 * overlap, so limit what we read at that boundary if
2466 if (img_offset + length > rbd_dev->parent_overlap) {
2467 rbd_assert(img_offset < rbd_dev->parent_overlap);
2468 length = rbd_dev->parent_overlap - img_offset;
2472 * Allocate a page array big enough to receive the data read
2475 page_count = (u32)calc_pages_for(0, length);
2476 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2477 if (IS_ERR(pages)) {
2478 result = PTR_ERR(pages);
2484 parent_request = rbd_parent_request_create(obj_request,
2485 img_offset, length);
2486 if (!parent_request)
2489 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2492 parent_request->copyup_pages = pages;
2493 parent_request->copyup_page_count = page_count;
2495 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2496 result = rbd_img_request_submit(parent_request);
2500 parent_request->copyup_pages = NULL;
2501 parent_request->copyup_page_count = 0;
2502 parent_request->obj_request = NULL;
2503 rbd_obj_request_put(obj_request);
2506 ceph_release_page_vector(pages, page_count);
2508 rbd_img_request_put(parent_request);
2509 obj_request->result = result;
2510 obj_request->xferred = 0;
2511 obj_request_done_set(obj_request);
2516 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2518 struct rbd_obj_request *orig_request;
2521 rbd_assert(!obj_request_img_data_test(obj_request));
2524 * All we need from the object request is the original
2525 * request and the result of the STAT op. Grab those, then
2526 * we're done with the request.
2528 orig_request = obj_request->obj_request;
2529 obj_request->obj_request = NULL;
2530 rbd_assert(orig_request);
2531 rbd_assert(orig_request->img_request);
2533 result = obj_request->result;
2534 obj_request->result = 0;
2536 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2537 obj_request, orig_request, result,
2538 obj_request->xferred, obj_request->length);
2539 rbd_obj_request_put(obj_request);
2541 rbd_assert(orig_request);
2542 rbd_assert(orig_request->img_request);
2545 * Our only purpose here is to determine whether the object
2546 * exists, and we don't want to treat the non-existence as
2547 * an error. If something else comes back, transfer the
2548 * error to the original request and complete it now.
2551 obj_request_existence_set(orig_request, true);
2552 } else if (result == -ENOENT) {
2553 obj_request_existence_set(orig_request, false);
2554 } else if (result) {
2555 orig_request->result = result;
2560 * Resubmit the original request now that we have recorded
2561 * whether the target object exists.
2563 orig_request->result = rbd_img_obj_request_submit(orig_request);
2565 if (orig_request->result)
2566 rbd_obj_request_complete(orig_request);
2567 rbd_obj_request_put(orig_request);
2570 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2572 struct rbd_obj_request *stat_request;
2573 struct rbd_device *rbd_dev;
2574 struct ceph_osd_client *osdc;
2575 struct page **pages = NULL;
2581 * The response data for a STAT call consists of:
2588 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2589 page_count = (u32)calc_pages_for(0, size);
2590 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2592 return PTR_ERR(pages);
2595 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2600 rbd_obj_request_get(obj_request);
2601 stat_request->obj_request = obj_request;
2602 stat_request->pages = pages;
2603 stat_request->page_count = page_count;
2605 rbd_assert(obj_request->img_request);
2606 rbd_dev = obj_request->img_request->rbd_dev;
2607 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2609 if (!stat_request->osd_req)
2611 stat_request->callback = rbd_img_obj_exists_callback;
2613 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2614 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2616 rbd_osd_req_format_read(stat_request);
2618 osdc = &rbd_dev->rbd_client->client->osdc;
2619 ret = rbd_obj_request_submit(osdc, stat_request);
2622 rbd_obj_request_put(obj_request);
2627 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2629 struct rbd_img_request *img_request;
2630 struct rbd_device *rbd_dev;
2633 rbd_assert(obj_request_img_data_test(obj_request));
2635 img_request = obj_request->img_request;
2636 rbd_assert(img_request);
2637 rbd_dev = img_request->rbd_dev;
2640 * Only writes to layered images need special handling.
2641 * Reads and non-layered writes are simple object requests.
2642 * Layered writes that start beyond the end of the overlap
2643 * with the parent have no parent data, so they too are
2644 * simple object requests. Finally, if the target object is
2645 * known to already exist, its parent data has already been
2646 * copied, so a write to the object can also be handled as a
2647 * simple object request.
2649 if (!img_request_write_test(img_request) ||
2650 !img_request_layered_test(img_request) ||
2651 rbd_dev->parent_overlap <= obj_request->img_offset ||
2652 ((known = obj_request_known_test(obj_request)) &&
2653 obj_request_exists_test(obj_request))) {
2655 struct rbd_device *rbd_dev;
2656 struct ceph_osd_client *osdc;
2658 rbd_dev = obj_request->img_request->rbd_dev;
2659 osdc = &rbd_dev->rbd_client->client->osdc;
2661 return rbd_obj_request_submit(osdc, obj_request);
2665 * It's a layered write. The target object might exist but
2666 * we may not know that yet. If we know it doesn't exist,
2667 * start by reading the data for the full target object from
2668 * the parent so we can use it for a copyup to the target.
2671 return rbd_img_obj_parent_read_full(obj_request);
2673 /* We don't know whether the target exists. Go find out. */
2675 return rbd_img_obj_exists_submit(obj_request);
2678 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2680 struct rbd_obj_request *obj_request;
2681 struct rbd_obj_request *next_obj_request;
2683 dout("%s: img %p\n", __func__, img_request);
2684 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2687 ret = rbd_img_obj_request_submit(obj_request);
2695 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2697 struct rbd_obj_request *obj_request;
2698 struct rbd_device *rbd_dev;
2703 rbd_assert(img_request_child_test(img_request));
2705 /* First get what we need from the image request and release it */
2707 obj_request = img_request->obj_request;
2708 img_xferred = img_request->xferred;
2709 img_result = img_request->result;
2710 rbd_img_request_put(img_request);
2713 * If the overlap has become 0 (most likely because the
2714 * image has been flattened) we need to re-submit the
2717 rbd_assert(obj_request);
2718 rbd_assert(obj_request->img_request);
2719 rbd_dev = obj_request->img_request->rbd_dev;
2720 if (!rbd_dev->parent_overlap) {
2721 struct ceph_osd_client *osdc;
2723 osdc = &rbd_dev->rbd_client->client->osdc;
2724 img_result = rbd_obj_request_submit(osdc, obj_request);
2729 obj_request->result = img_result;
2730 if (obj_request->result)
2734 * We need to zero anything beyond the parent overlap
2735 * boundary. Since rbd_img_obj_request_read_callback()
2736 * will zero anything beyond the end of a short read, an
2737 * easy way to do this is to pretend the data from the
2738 * parent came up short--ending at the overlap boundary.
2740 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2741 obj_end = obj_request->img_offset + obj_request->length;
2742 if (obj_end > rbd_dev->parent_overlap) {
2745 if (obj_request->img_offset < rbd_dev->parent_overlap)
2746 xferred = rbd_dev->parent_overlap -
2747 obj_request->img_offset;
2749 obj_request->xferred = min(img_xferred, xferred);
2751 obj_request->xferred = img_xferred;
2754 rbd_img_obj_request_read_callback(obj_request);
2755 rbd_obj_request_complete(obj_request);
2758 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2760 struct rbd_img_request *img_request;
2763 rbd_assert(obj_request_img_data_test(obj_request));
2764 rbd_assert(obj_request->img_request != NULL);
2765 rbd_assert(obj_request->result == (s32) -ENOENT);
2766 rbd_assert(obj_request_type_valid(obj_request->type));
2768 /* rbd_read_finish(obj_request, obj_request->length); */
2769 img_request = rbd_parent_request_create(obj_request,
2770 obj_request->img_offset,
2771 obj_request->length);
2776 if (obj_request->type == OBJ_REQUEST_BIO)
2777 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2778 obj_request->bio_list);
2780 result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
2781 obj_request->pages);
2785 img_request->callback = rbd_img_parent_read_callback;
2786 result = rbd_img_request_submit(img_request);
2793 rbd_img_request_put(img_request);
2794 obj_request->result = result;
2795 obj_request->xferred = 0;
2796 obj_request_done_set(obj_request);
2799 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
2801 struct rbd_obj_request *obj_request;
2802 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2805 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2806 OBJ_REQUEST_NODATA);
2811 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2812 if (!obj_request->osd_req)
2814 obj_request->callback = rbd_obj_request_put;
2816 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2818 rbd_osd_req_format_read(obj_request);
2820 ret = rbd_obj_request_submit(osdc, obj_request);
2823 rbd_obj_request_put(obj_request);
2828 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2830 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2836 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2837 rbd_dev->header_name, (unsigned long long)notify_id,
2838 (unsigned int)opcode);
2839 ret = rbd_dev_refresh(rbd_dev);
2841 rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);
2843 rbd_obj_notify_ack(rbd_dev, notify_id);
2847 * Request sync osd watch/unwatch. The value of "start" determines
2848 * whether a watch request is being initiated or torn down.
2850 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start)
2852 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2853 struct rbd_obj_request *obj_request;
2856 rbd_assert(start ^ !!rbd_dev->watch_event);
2857 rbd_assert(start ^ !!rbd_dev->watch_request);
2860 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2861 &rbd_dev->watch_event);
2864 rbd_assert(rbd_dev->watch_event != NULL);
2868 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2869 OBJ_REQUEST_NODATA);
2873 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2874 if (!obj_request->osd_req)
2878 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2880 ceph_osdc_unregister_linger_request(osdc,
2881 rbd_dev->watch_request->osd_req);
2883 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2884 rbd_dev->watch_event->cookie, 0, start ? 1 : 0);
2885 rbd_osd_req_format_write(obj_request);
2887 ret = rbd_obj_request_submit(osdc, obj_request);
2890 ret = rbd_obj_request_wait(obj_request);
2893 ret = obj_request->result;
2898 * A watch request is set to linger, so the underlying osd
2899 * request won't go away until we unregister it. We retain
2900 * a pointer to the object request during that time (in
2901 * rbd_dev->watch_request), so we'll keep a reference to
2902 * it. We'll drop that reference (below) after we've
2906 rbd_dev->watch_request = obj_request;
2911 /* We have successfully torn down the watch request */
2913 rbd_obj_request_put(rbd_dev->watch_request);
2914 rbd_dev->watch_request = NULL;
2916 /* Cancel the event if we're tearing down, or on error */
2917 ceph_osdc_cancel_event(rbd_dev->watch_event);
2918 rbd_dev->watch_event = NULL;
2920 rbd_obj_request_put(obj_request);
2926 * Synchronous osd object method call. Returns the number of bytes
2927 * returned in the outbound buffer, or a negative error code.
2929 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2930 const char *object_name,
2931 const char *class_name,
2932 const char *method_name,
2933 const void *outbound,
2934 size_t outbound_size,
2936 size_t inbound_size)
2938 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2939 struct rbd_obj_request *obj_request;
2940 struct page **pages;
2945 * Method calls are ultimately read operations. The result
2946 * should placed into the inbound buffer provided. They
2947 * also supply outbound data--parameters for the object
2948 * method. Currently if this is present it will be a
2951 page_count = (u32)calc_pages_for(0, inbound_size);
2952 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2954 return PTR_ERR(pages);
2957 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2962 obj_request->pages = pages;
2963 obj_request->page_count = page_count;
2965 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2966 if (!obj_request->osd_req)
2969 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2970 class_name, method_name);
2971 if (outbound_size) {
2972 struct ceph_pagelist *pagelist;
2974 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2978 ceph_pagelist_init(pagelist);
2979 ceph_pagelist_append(pagelist, outbound, outbound_size);
2980 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2983 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2984 obj_request->pages, inbound_size,
2986 rbd_osd_req_format_read(obj_request);
2988 ret = rbd_obj_request_submit(osdc, obj_request);
2991 ret = rbd_obj_request_wait(obj_request);
2995 ret = obj_request->result;
2999 rbd_assert(obj_request->xferred < (u64)INT_MAX);
3000 ret = (int)obj_request->xferred;
3001 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
3004 rbd_obj_request_put(obj_request);
3006 ceph_release_page_vector(pages, page_count);
3011 static void rbd_request_fn(struct request_queue *q)
3012 __releases(q->queue_lock) __acquires(q->queue_lock)
3014 struct rbd_device *rbd_dev = q->queuedata;
3015 bool read_only = rbd_dev->mapping.read_only;
3019 while ((rq = blk_fetch_request(q))) {
3020 bool write_request = rq_data_dir(rq) == WRITE;
3021 struct rbd_img_request *img_request;
3025 /* Ignore any non-FS requests that filter through. */
3027 if (rq->cmd_type != REQ_TYPE_FS) {
3028 dout("%s: non-fs request type %d\n", __func__,
3029 (int) rq->cmd_type);
3030 __blk_end_request_all(rq, 0);
3034 /* Ignore/skip any zero-length requests */
3036 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
3037 length = (u64) blk_rq_bytes(rq);
3040 dout("%s: zero-length request\n", __func__);
3041 __blk_end_request_all(rq, 0);
3045 spin_unlock_irq(q->queue_lock);
3047 /* Disallow writes to a read-only device */
3049 if (write_request) {
3053 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
3057 * Quit early if the mapped snapshot no longer
3058 * exists. It's still possible the snapshot will
3059 * have disappeared by the time our request arrives
3060 * at the osd, but there's no sense in sending it if
3063 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
3064 dout("request for non-existent snapshot");
3065 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
3071 if (offset && length > U64_MAX - offset + 1) {
3072 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
3074 goto end_request; /* Shouldn't happen */
3078 if (offset + length > rbd_dev->mapping.size) {
3079 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)\n",
3080 offset, length, rbd_dev->mapping.size);
3085 img_request = rbd_img_request_create(rbd_dev, offset, length,
3090 img_request->rq = rq;
3092 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3095 result = rbd_img_request_submit(img_request);
3097 rbd_img_request_put(img_request);
3099 spin_lock_irq(q->queue_lock);
3101 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
3102 write_request ? "write" : "read",
3103 length, offset, result);
3105 __blk_end_request_all(rq, result);
3111 * a queue callback. Makes sure that we don't create a bio that spans across
3112 * multiple osd objects. One exception would be with a single page bios,
3113 * which we handle later at bio_chain_clone_range()
3115 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
3116 struct bio_vec *bvec)
3118 struct rbd_device *rbd_dev = q->queuedata;
3119 sector_t sector_offset;
3120 sector_t sectors_per_obj;
3121 sector_t obj_sector_offset;
3125 * Find how far into its rbd object the partition-relative
3126 * bio start sector is to offset relative to the enclosing
3129 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
3130 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
3131 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
3134 * Compute the number of bytes from that offset to the end
3135 * of the object. Account for what's already used by the bio.
3137 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
3138 if (ret > bmd->bi_size)
3139 ret -= bmd->bi_size;
3144 * Don't send back more than was asked for. And if the bio
3145 * was empty, let the whole thing through because: "Note
3146 * that a block device *must* allow a single page to be
3147 * added to an empty bio."
3149 rbd_assert(bvec->bv_len <= PAGE_SIZE);
3150 if (ret > (int) bvec->bv_len || !bmd->bi_size)
3151 ret = (int) bvec->bv_len;
3156 static void rbd_free_disk(struct rbd_device *rbd_dev)
3158 struct gendisk *disk = rbd_dev->disk;
3163 rbd_dev->disk = NULL;
3164 if (disk->flags & GENHD_FL_UP) {
3167 blk_cleanup_queue(disk->queue);
3172 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
3173 const char *object_name,
3174 u64 offset, u64 length, void *buf)
3177 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3178 struct rbd_obj_request *obj_request;
3179 struct page **pages = NULL;
3184 page_count = (u32) calc_pages_for(offset, length);
3185 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
3187 ret = PTR_ERR(pages);
3190 obj_request = rbd_obj_request_create(object_name, offset, length,
3195 obj_request->pages = pages;
3196 obj_request->page_count = page_count;
3198 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
3199 if (!obj_request->osd_req)
3202 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
3203 offset, length, 0, 0);
3204 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
3206 obj_request->length,
3207 obj_request->offset & ~PAGE_MASK,
3209 rbd_osd_req_format_read(obj_request);
3211 ret = rbd_obj_request_submit(osdc, obj_request);
3214 ret = rbd_obj_request_wait(obj_request);
3218 ret = obj_request->result;
3222 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
3223 size = (size_t) obj_request->xferred;
3224 ceph_copy_from_page_vector(pages, buf, 0, size);
3225 rbd_assert(size <= (size_t)INT_MAX);
3229 rbd_obj_request_put(obj_request);
3231 ceph_release_page_vector(pages, page_count);
3237 * Read the complete header for the given rbd device. On successful
3238 * return, the rbd_dev->header field will contain up-to-date
3239 * information about the image.
3241 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3243 struct rbd_image_header_ondisk *ondisk = NULL;
3250 * The complete header will include an array of its 64-bit
3251 * snapshot ids, followed by the names of those snapshots as
3252 * a contiguous block of NUL-terminated strings. Note that
3253 * the number of snapshots could change by the time we read
3254 * it in, in which case we re-read it.
3261 size = sizeof (*ondisk);
3262 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
3264 ondisk = kmalloc(size, GFP_KERNEL);
3268 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3272 if ((size_t)ret < size) {
3274 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
3278 if (!rbd_dev_ondisk_valid(ondisk)) {
3280 rbd_warn(rbd_dev, "invalid header");
3284 names_size = le64_to_cpu(ondisk->snap_names_len);
3285 want_count = snap_count;
3286 snap_count = le32_to_cpu(ondisk->snap_count);
3287 } while (snap_count != want_count);
3289 ret = rbd_header_from_disk(rbd_dev, ondisk);
3297 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
3298 * has disappeared from the (just updated) snapshot context.
3300 static void rbd_exists_validate(struct rbd_device *rbd_dev)
3304 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
3307 snap_id = rbd_dev->spec->snap_id;
3308 if (snap_id == CEPH_NOSNAP)
3311 if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
3312 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3315 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3320 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3321 mapping_size = rbd_dev->mapping.size;
3322 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3323 if (rbd_dev->image_format == 1)
3324 ret = rbd_dev_v1_header_info(rbd_dev);
3326 ret = rbd_dev_v2_header_info(rbd_dev);
3328 /* If it's a mapped snapshot, validate its EXISTS flag */
3330 rbd_exists_validate(rbd_dev);
3331 mutex_unlock(&ctl_mutex);
3332 if (mapping_size != rbd_dev->mapping.size) {
3335 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3336 dout("setting size to %llu sectors", (unsigned long long)size);
3337 set_capacity(rbd_dev->disk, size);
3338 revalidate_disk(rbd_dev->disk);
3344 static int rbd_init_disk(struct rbd_device *rbd_dev)
3346 struct gendisk *disk;
3347 struct request_queue *q;
3350 /* create gendisk info */
3351 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3355 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3357 disk->major = rbd_dev->major;
3358 disk->first_minor = 0;
3359 disk->fops = &rbd_bd_ops;
3360 disk->private_data = rbd_dev;
3362 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3366 /* We use the default size, but let's be explicit about it. */
3367 blk_queue_physical_block_size(q, SECTOR_SIZE);
3369 /* set io sizes to object size */
3370 segment_size = rbd_obj_bytes(&rbd_dev->header);
3371 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3372 blk_queue_max_segment_size(q, segment_size);
3373 blk_queue_io_min(q, segment_size);
3374 blk_queue_io_opt(q, segment_size);
3376 blk_queue_merge_bvec(q, rbd_merge_bvec);
3379 q->queuedata = rbd_dev;
3381 rbd_dev->disk = disk;
3394 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3396 return container_of(dev, struct rbd_device, dev);
3399 static ssize_t rbd_size_show(struct device *dev,
3400 struct device_attribute *attr, char *buf)
3402 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3404 return sprintf(buf, "%llu\n",
3405 (unsigned long long)rbd_dev->mapping.size);
3409 * Note this shows the features for whatever's mapped, which is not
3410 * necessarily the base image.
3412 static ssize_t rbd_features_show(struct device *dev,
3413 struct device_attribute *attr, char *buf)
3415 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3417 return sprintf(buf, "0x%016llx\n",
3418 (unsigned long long)rbd_dev->mapping.features);
3421 static ssize_t rbd_major_show(struct device *dev,
3422 struct device_attribute *attr, char *buf)
3424 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3427 return sprintf(buf, "%d\n", rbd_dev->major);
3429 return sprintf(buf, "(none)\n");
3433 static ssize_t rbd_client_id_show(struct device *dev,
3434 struct device_attribute *attr, char *buf)
3436 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3438 return sprintf(buf, "client%lld\n",
3439 ceph_client_id(rbd_dev->rbd_client->client));
3442 static ssize_t rbd_pool_show(struct device *dev,
3443 struct device_attribute *attr, char *buf)
3445 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3447 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3450 static ssize_t rbd_pool_id_show(struct device *dev,
3451 struct device_attribute *attr, char *buf)
3453 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3455 return sprintf(buf, "%llu\n",
3456 (unsigned long long) rbd_dev->spec->pool_id);
3459 static ssize_t rbd_name_show(struct device *dev,
3460 struct device_attribute *attr, char *buf)
3462 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3464 if (rbd_dev->spec->image_name)
3465 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3467 return sprintf(buf, "(unknown)\n");
3470 static ssize_t rbd_image_id_show(struct device *dev,
3471 struct device_attribute *attr, char *buf)
3473 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3475 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3479 * Shows the name of the currently-mapped snapshot (or
3480 * RBD_SNAP_HEAD_NAME for the base image).
3482 static ssize_t rbd_snap_show(struct device *dev,
3483 struct device_attribute *attr,
3486 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3488 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3492 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3493 * for the parent image. If there is no parent, simply shows
3494 * "(no parent image)".
3496 static ssize_t rbd_parent_show(struct device *dev,
3497 struct device_attribute *attr,
3500 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3501 struct rbd_spec *spec = rbd_dev->parent_spec;
3506 return sprintf(buf, "(no parent image)\n");
3508 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3509 (unsigned long long) spec->pool_id, spec->pool_name);
3514 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3515 spec->image_name ? spec->image_name : "(unknown)");
3520 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3521 (unsigned long long) spec->snap_id, spec->snap_name);
3526 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3531 return (ssize_t) (bufp - buf);
3534 static ssize_t rbd_image_refresh(struct device *dev,
3535 struct device_attribute *attr,
3539 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3542 ret = rbd_dev_refresh(rbd_dev);
3544 rbd_warn(rbd_dev, ": manual header refresh error (%d)\n", ret);
3546 return ret < 0 ? ret : size;
3549 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3550 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3551 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3552 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3553 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3554 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3555 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3556 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3557 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3558 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3559 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3561 static struct attribute *rbd_attrs[] = {
3562 &dev_attr_size.attr,
3563 &dev_attr_features.attr,
3564 &dev_attr_major.attr,
3565 &dev_attr_client_id.attr,
3566 &dev_attr_pool.attr,
3567 &dev_attr_pool_id.attr,
3568 &dev_attr_name.attr,
3569 &dev_attr_image_id.attr,
3570 &dev_attr_current_snap.attr,
3571 &dev_attr_parent.attr,
3572 &dev_attr_refresh.attr,
3576 static struct attribute_group rbd_attr_group = {
3580 static const struct attribute_group *rbd_attr_groups[] = {
3585 static void rbd_sysfs_dev_release(struct device *dev)
3589 static struct device_type rbd_device_type = {
3591 .groups = rbd_attr_groups,
3592 .release = rbd_sysfs_dev_release,
3595 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3597 kref_get(&spec->kref);
3602 static void rbd_spec_free(struct kref *kref);
3603 static void rbd_spec_put(struct rbd_spec *spec)
3606 kref_put(&spec->kref, rbd_spec_free);
3609 static struct rbd_spec *rbd_spec_alloc(void)
3611 struct rbd_spec *spec;
3613 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3616 kref_init(&spec->kref);
3621 static void rbd_spec_free(struct kref *kref)
3623 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3625 kfree(spec->pool_name);
3626 kfree(spec->image_id);
3627 kfree(spec->image_name);
3628 kfree(spec->snap_name);
3632 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3633 struct rbd_spec *spec)
3635 struct rbd_device *rbd_dev;
3637 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3641 spin_lock_init(&rbd_dev->lock);
3643 atomic_set(&rbd_dev->parent_ref, 0);
3644 INIT_LIST_HEAD(&rbd_dev->node);
3645 init_rwsem(&rbd_dev->header_rwsem);
3647 rbd_dev->spec = spec;
3648 rbd_dev->rbd_client = rbdc;
3650 /* Initialize the layout used for all rbd requests */
3652 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3653 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3654 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3655 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3660 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3662 rbd_put_client(rbd_dev->rbd_client);
3663 rbd_spec_put(rbd_dev->spec);
3668 * Get the size and object order for an image snapshot, or if
3669 * snap_id is CEPH_NOSNAP, gets this information for the base
3672 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3673 u8 *order, u64 *snap_size)
3675 __le64 snapid = cpu_to_le64(snap_id);
3680 } __attribute__ ((packed)) size_buf = { 0 };
3682 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3684 &snapid, sizeof (snapid),
3685 &size_buf, sizeof (size_buf));
3686 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3689 if (ret < sizeof (size_buf))
3693 *order = size_buf.order;
3694 *snap_size = le64_to_cpu(size_buf.size);
3696 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3697 (unsigned long long)snap_id, (unsigned int)*order,
3698 (unsigned long long)*snap_size);
3703 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3705 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3706 &rbd_dev->header.obj_order,
3707 &rbd_dev->header.image_size);
3710 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3716 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3720 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3721 "rbd", "get_object_prefix", NULL, 0,
3722 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
3723 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3728 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3729 p + ret, NULL, GFP_NOIO);
3732 if (IS_ERR(rbd_dev->header.object_prefix)) {
3733 ret = PTR_ERR(rbd_dev->header.object_prefix);
3734 rbd_dev->header.object_prefix = NULL;
3736 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3744 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3747 __le64 snapid = cpu_to_le64(snap_id);
3751 } __attribute__ ((packed)) features_buf = { 0 };
3755 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3756 "rbd", "get_features",
3757 &snapid, sizeof (snapid),
3758 &features_buf, sizeof (features_buf));
3759 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3762 if (ret < sizeof (features_buf))
3765 incompat = le64_to_cpu(features_buf.incompat);
3766 if (incompat & ~RBD_FEATURES_SUPPORTED)
3769 *snap_features = le64_to_cpu(features_buf.features);
3771 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3772 (unsigned long long)snap_id,
3773 (unsigned long long)*snap_features,
3774 (unsigned long long)le64_to_cpu(features_buf.incompat));
3779 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3781 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3782 &rbd_dev->header.features);
3785 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3787 struct rbd_spec *parent_spec;
3789 void *reply_buf = NULL;
3798 parent_spec = rbd_spec_alloc();
3802 size = sizeof (__le64) + /* pool_id */
3803 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3804 sizeof (__le64) + /* snap_id */
3805 sizeof (__le64); /* overlap */
3806 reply_buf = kmalloc(size, GFP_KERNEL);
3812 snapid = cpu_to_le64(CEPH_NOSNAP);
3813 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3814 "rbd", "get_parent",
3815 &snapid, sizeof (snapid),
3817 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3822 end = reply_buf + ret;
3824 ceph_decode_64_safe(&p, end, pool_id, out_err);
3825 if (pool_id == CEPH_NOPOOL) {
3827 * Either the parent never existed, or we have
3828 * record of it but the image got flattened so it no
3829 * longer has a parent. When the parent of a
3830 * layered image disappears we immediately set the
3831 * overlap to 0. The effect of this is that all new
3832 * requests will be treated as if the image had no
3835 if (rbd_dev->parent_overlap) {
3836 rbd_dev->parent_overlap = 0;
3838 rbd_dev_parent_put(rbd_dev);
3839 pr_info("%s: clone image has been flattened\n",
3840 rbd_dev->disk->disk_name);
3843 goto out; /* No parent? No problem. */
3846 /* The ceph file layout needs to fit pool id in 32 bits */
3849 if (pool_id > (u64)U32_MAX) {
3850 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3851 (unsigned long long)pool_id, U32_MAX);
3854 parent_spec->pool_id = pool_id;
3856 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3857 if (IS_ERR(image_id)) {
3858 ret = PTR_ERR(image_id);
3861 parent_spec->image_id = image_id;
3862 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3863 ceph_decode_64_safe(&p, end, overlap, out_err);
3866 rbd_spec_put(rbd_dev->parent_spec);
3867 rbd_dev->parent_spec = parent_spec;
3868 parent_spec = NULL; /* rbd_dev now owns this */
3869 rbd_dev->parent_overlap = overlap;
3871 rbd_warn(rbd_dev, "ignoring parent of clone with overlap 0\n");
3877 rbd_spec_put(parent_spec);
3882 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3886 __le64 stripe_count;
3887 } __attribute__ ((packed)) striping_info_buf = { 0 };
3888 size_t size = sizeof (striping_info_buf);
3895 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3896 "rbd", "get_stripe_unit_count", NULL, 0,
3897 (char *)&striping_info_buf, size);
3898 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3905 * We don't actually support the "fancy striping" feature
3906 * (STRIPINGV2) yet, but if the striping sizes are the
3907 * defaults the behavior is the same as before. So find
3908 * out, and only fail if the image has non-default values.
3911 obj_size = (u64)1 << rbd_dev->header.obj_order;
3912 p = &striping_info_buf;
3913 stripe_unit = ceph_decode_64(&p);
3914 if (stripe_unit != obj_size) {
3915 rbd_warn(rbd_dev, "unsupported stripe unit "
3916 "(got %llu want %llu)",
3917 stripe_unit, obj_size);
3920 stripe_count = ceph_decode_64(&p);
3921 if (stripe_count != 1) {
3922 rbd_warn(rbd_dev, "unsupported stripe count "
3923 "(got %llu want 1)", stripe_count);
3926 rbd_dev->header.stripe_unit = stripe_unit;
3927 rbd_dev->header.stripe_count = stripe_count;
3932 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3934 size_t image_id_size;
3939 void *reply_buf = NULL;
3941 char *image_name = NULL;
3944 rbd_assert(!rbd_dev->spec->image_name);
3946 len = strlen(rbd_dev->spec->image_id);
3947 image_id_size = sizeof (__le32) + len;
3948 image_id = kmalloc(image_id_size, GFP_KERNEL);
3953 end = image_id + image_id_size;
3954 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3956 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3957 reply_buf = kmalloc(size, GFP_KERNEL);
3961 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3962 "rbd", "dir_get_name",
3963 image_id, image_id_size,
3968 end = reply_buf + ret;
3970 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3971 if (IS_ERR(image_name))
3974 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3982 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3984 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3985 const char *snap_name;
3988 /* Skip over names until we find the one we are looking for */
3990 snap_name = rbd_dev->header.snap_names;
3991 while (which < snapc->num_snaps) {
3992 if (!strcmp(name, snap_name))
3993 return snapc->snaps[which];
3994 snap_name += strlen(snap_name) + 1;
4000 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
4002 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
4007 for (which = 0; !found && which < snapc->num_snaps; which++) {
4008 const char *snap_name;
4010 snap_id = snapc->snaps[which];
4011 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
4012 if (IS_ERR(snap_name))
4014 found = !strcmp(name, snap_name);
4017 return found ? snap_id : CEPH_NOSNAP;
4021 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
4022 * no snapshot by that name is found, or if an error occurs.
4024 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
4026 if (rbd_dev->image_format == 1)
4027 return rbd_v1_snap_id_by_name(rbd_dev, name);
4029 return rbd_v2_snap_id_by_name(rbd_dev, name);
4033 * When an rbd image has a parent image, it is identified by the
4034 * pool, image, and snapshot ids (not names). This function fills
4035 * in the names for those ids. (It's OK if we can't figure out the
4036 * name for an image id, but the pool and snapshot ids should always
4037 * exist and have names.) All names in an rbd spec are dynamically
4040 * When an image being mapped (not a parent) is probed, we have the
4041 * pool name and pool id, image name and image id, and the snapshot
4042 * name. The only thing we're missing is the snapshot id.
4044 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
4046 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4047 struct rbd_spec *spec = rbd_dev->spec;
4048 const char *pool_name;
4049 const char *image_name;
4050 const char *snap_name;
4054 * An image being mapped will have the pool name (etc.), but
4055 * we need to look up the snapshot id.
4057 if (spec->pool_name) {
4058 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
4061 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
4062 if (snap_id == CEPH_NOSNAP)
4064 spec->snap_id = snap_id;
4066 spec->snap_id = CEPH_NOSNAP;
4072 /* Get the pool name; we have to make our own copy of this */
4074 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
4076 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
4079 pool_name = kstrdup(pool_name, GFP_KERNEL);
4083 /* Fetch the image name; tolerate failure here */
4085 image_name = rbd_dev_image_name(rbd_dev);
4087 rbd_warn(rbd_dev, "unable to get image name");
4089 /* Look up the snapshot name, and make a copy */
4091 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4097 spec->pool_name = pool_name;
4098 spec->image_name = image_name;
4099 spec->snap_name = snap_name;
4109 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4118 struct ceph_snap_context *snapc;
4122 * We'll need room for the seq value (maximum snapshot id),
4123 * snapshot count, and array of that many snapshot ids.
4124 * For now we have a fixed upper limit on the number we're
4125 * prepared to receive.
4127 size = sizeof (__le64) + sizeof (__le32) +
4128 RBD_MAX_SNAP_COUNT * sizeof (__le64);
4129 reply_buf = kzalloc(size, GFP_KERNEL);
4133 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4134 "rbd", "get_snapcontext", NULL, 0,
4136 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4141 end = reply_buf + ret;
4143 ceph_decode_64_safe(&p, end, seq, out);
4144 ceph_decode_32_safe(&p, end, snap_count, out);
4147 * Make sure the reported number of snapshot ids wouldn't go
4148 * beyond the end of our buffer. But before checking that,
4149 * make sure the computed size of the snapshot context we
4150 * allocate is representable in a size_t.
4152 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
4157 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
4161 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4167 for (i = 0; i < snap_count; i++)
4168 snapc->snaps[i] = ceph_decode_64(&p);
4170 ceph_put_snap_context(rbd_dev->header.snapc);
4171 rbd_dev->header.snapc = snapc;
4173 dout(" snap context seq = %llu, snap_count = %u\n",
4174 (unsigned long long)seq, (unsigned int)snap_count);
4181 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
4192 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
4193 reply_buf = kmalloc(size, GFP_KERNEL);
4195 return ERR_PTR(-ENOMEM);
4197 snapid = cpu_to_le64(snap_id);
4198 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4199 "rbd", "get_snapshot_name",
4200 &snapid, sizeof (snapid),
4202 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4204 snap_name = ERR_PTR(ret);
4209 end = reply_buf + ret;
4210 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4211 if (IS_ERR(snap_name))
4214 dout(" snap_id 0x%016llx snap_name = %s\n",
4215 (unsigned long long)snap_id, snap_name);
4222 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
4224 bool first_time = rbd_dev->header.object_prefix == NULL;
4227 down_write(&rbd_dev->header_rwsem);
4230 ret = rbd_dev_v2_header_onetime(rbd_dev);
4236 * If the image supports layering, get the parent info. We
4237 * need to probe the first time regardless. Thereafter we
4238 * only need to if there's a parent, to see if it has
4239 * disappeared due to the mapped image getting flattened.
4241 if (rbd_dev->header.features & RBD_FEATURE_LAYERING &&
4242 (first_time || rbd_dev->parent_spec)) {
4245 ret = rbd_dev_v2_parent_info(rbd_dev);
4250 * Print a warning if this is the initial probe and
4251 * the image has a parent. Don't print it if the
4252 * image now being probed is itself a parent. We
4253 * can tell at this point because we won't know its
4254 * pool name yet (just its pool id).
4256 warn = rbd_dev->parent_spec && rbd_dev->spec->pool_name;
4257 if (first_time && warn)
4258 rbd_warn(rbd_dev, "WARNING: kernel layering "
4259 "is EXPERIMENTAL!");
4262 ret = rbd_dev_v2_image_size(rbd_dev);
4266 if (rbd_dev->spec->snap_id == CEPH_NOSNAP)
4267 if (rbd_dev->mapping.size != rbd_dev->header.image_size)
4268 rbd_dev->mapping.size = rbd_dev->header.image_size;
4270 ret = rbd_dev_v2_snap_context(rbd_dev);
4271 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4273 up_write(&rbd_dev->header_rwsem);
4278 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4283 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4285 dev = &rbd_dev->dev;
4286 dev->bus = &rbd_bus_type;
4287 dev->type = &rbd_device_type;
4288 dev->parent = &rbd_root_dev;
4289 dev->release = rbd_dev_device_release;
4290 dev_set_name(dev, "%d", rbd_dev->dev_id);
4291 ret = device_register(dev);
4293 mutex_unlock(&ctl_mutex);
4298 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4300 device_unregister(&rbd_dev->dev);
4303 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4306 * Get a unique rbd identifier for the given new rbd_dev, and add
4307 * the rbd_dev to the global list. The minimum rbd id is 1.
4309 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4311 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4313 spin_lock(&rbd_dev_list_lock);
4314 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4315 spin_unlock(&rbd_dev_list_lock);
4316 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4317 (unsigned long long) rbd_dev->dev_id);
4321 * Remove an rbd_dev from the global list, and record that its
4322 * identifier is no longer in use.
4324 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4326 struct list_head *tmp;
4327 int rbd_id = rbd_dev->dev_id;
4330 rbd_assert(rbd_id > 0);
4332 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4333 (unsigned long long) rbd_dev->dev_id);
4334 spin_lock(&rbd_dev_list_lock);
4335 list_del_init(&rbd_dev->node);
4338 * If the id being "put" is not the current maximum, there
4339 * is nothing special we need to do.
4341 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4342 spin_unlock(&rbd_dev_list_lock);
4347 * We need to update the current maximum id. Search the
4348 * list to find out what it is. We're more likely to find
4349 * the maximum at the end, so search the list backward.
4352 list_for_each_prev(tmp, &rbd_dev_list) {
4353 struct rbd_device *rbd_dev;
4355 rbd_dev = list_entry(tmp, struct rbd_device, node);
4356 if (rbd_dev->dev_id > max_id)
4357 max_id = rbd_dev->dev_id;
4359 spin_unlock(&rbd_dev_list_lock);
4362 * The max id could have been updated by rbd_dev_id_get(), in
4363 * which case it now accurately reflects the new maximum.
4364 * Be careful not to overwrite the maximum value in that
4367 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4368 dout(" max dev id has been reset\n");
4372 * Skips over white space at *buf, and updates *buf to point to the
4373 * first found non-space character (if any). Returns the length of
4374 * the token (string of non-white space characters) found. Note
4375 * that *buf must be terminated with '\0'.
4377 static inline size_t next_token(const char **buf)
4380 * These are the characters that produce nonzero for
4381 * isspace() in the "C" and "POSIX" locales.
4383 const char *spaces = " \f\n\r\t\v";
4385 *buf += strspn(*buf, spaces); /* Find start of token */
4387 return strcspn(*buf, spaces); /* Return token length */
4391 * Finds the next token in *buf, and if the provided token buffer is
4392 * big enough, copies the found token into it. The result, if
4393 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4394 * must be terminated with '\0' on entry.
4396 * Returns the length of the token found (not including the '\0').
4397 * Return value will be 0 if no token is found, and it will be >=
4398 * token_size if the token would not fit.
4400 * The *buf pointer will be updated to point beyond the end of the
4401 * found token. Note that this occurs even if the token buffer is
4402 * too small to hold it.
4404 static inline size_t copy_token(const char **buf,
4410 len = next_token(buf);
4411 if (len < token_size) {
4412 memcpy(token, *buf, len);
4413 *(token + len) = '\0';
4421 * Finds the next token in *buf, dynamically allocates a buffer big
4422 * enough to hold a copy of it, and copies the token into the new
4423 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4424 * that a duplicate buffer is created even for a zero-length token.
4426 * Returns a pointer to the newly-allocated duplicate, or a null
4427 * pointer if memory for the duplicate was not available. If
4428 * the lenp argument is a non-null pointer, the length of the token
4429 * (not including the '\0') is returned in *lenp.
4431 * If successful, the *buf pointer will be updated to point beyond
4432 * the end of the found token.
4434 * Note: uses GFP_KERNEL for allocation.
4436 static inline char *dup_token(const char **buf, size_t *lenp)
4441 len = next_token(buf);
4442 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4445 *(dup + len) = '\0';
4455 * Parse the options provided for an "rbd add" (i.e., rbd image
4456 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4457 * and the data written is passed here via a NUL-terminated buffer.
4458 * Returns 0 if successful or an error code otherwise.
4460 * The information extracted from these options is recorded in
4461 * the other parameters which return dynamically-allocated
4464 * The address of a pointer that will refer to a ceph options
4465 * structure. Caller must release the returned pointer using
4466 * ceph_destroy_options() when it is no longer needed.
4468 * Address of an rbd options pointer. Fully initialized by
4469 * this function; caller must release with kfree().
4471 * Address of an rbd image specification pointer. Fully
4472 * initialized by this function based on parsed options.
4473 * Caller must release with rbd_spec_put().
4475 * The options passed take this form:
4476 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4479 * A comma-separated list of one or more monitor addresses.
4480 * A monitor address is an ip address, optionally followed
4481 * by a port number (separated by a colon).
4482 * I.e.: ip1[:port1][,ip2[:port2]...]
4484 * A comma-separated list of ceph and/or rbd options.
4486 * The name of the rados pool containing the rbd image.
4488 * The name of the image in that pool to map.
4490 * An optional snapshot id. If provided, the mapping will
4491 * present data from the image at the time that snapshot was
4492 * created. The image head is used if no snapshot id is
4493 * provided. Snapshot mappings are always read-only.
4495 static int rbd_add_parse_args(const char *buf,
4496 struct ceph_options **ceph_opts,
4497 struct rbd_options **opts,
4498 struct rbd_spec **rbd_spec)
4502 const char *mon_addrs;
4504 size_t mon_addrs_size;
4505 struct rbd_spec *spec = NULL;
4506 struct rbd_options *rbd_opts = NULL;
4507 struct ceph_options *copts;
4510 /* The first four tokens are required */
4512 len = next_token(&buf);
4514 rbd_warn(NULL, "no monitor address(es) provided");
4518 mon_addrs_size = len + 1;
4522 options = dup_token(&buf, NULL);
4526 rbd_warn(NULL, "no options provided");
4530 spec = rbd_spec_alloc();
4534 spec->pool_name = dup_token(&buf, NULL);
4535 if (!spec->pool_name)
4537 if (!*spec->pool_name) {
4538 rbd_warn(NULL, "no pool name provided");
4542 spec->image_name = dup_token(&buf, NULL);
4543 if (!spec->image_name)
4545 if (!*spec->image_name) {
4546 rbd_warn(NULL, "no image name provided");
4551 * Snapshot name is optional; default is to use "-"
4552 * (indicating the head/no snapshot).
4554 len = next_token(&buf);
4556 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4557 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4558 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4559 ret = -ENAMETOOLONG;
4562 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4565 *(snap_name + len) = '\0';
4566 spec->snap_name = snap_name;
4568 /* Initialize all rbd options to the defaults */
4570 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4574 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4576 copts = ceph_parse_options(options, mon_addrs,
4577 mon_addrs + mon_addrs_size - 1,
4578 parse_rbd_opts_token, rbd_opts);
4579 if (IS_ERR(copts)) {
4580 ret = PTR_ERR(copts);
4601 * An rbd format 2 image has a unique identifier, distinct from the
4602 * name given to it by the user. Internally, that identifier is
4603 * what's used to specify the names of objects related to the image.
4605 * A special "rbd id" object is used to map an rbd image name to its
4606 * id. If that object doesn't exist, then there is no v2 rbd image
4607 * with the supplied name.
4609 * This function will record the given rbd_dev's image_id field if
4610 * it can be determined, and in that case will return 0. If any
4611 * errors occur a negative errno will be returned and the rbd_dev's
4612 * image_id field will be unchanged (and should be NULL).
4614 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4623 * When probing a parent image, the image id is already
4624 * known (and the image name likely is not). There's no
4625 * need to fetch the image id again in this case. We
4626 * do still need to set the image format though.
4628 if (rbd_dev->spec->image_id) {
4629 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4635 * First, see if the format 2 image id file exists, and if
4636 * so, get the image's persistent id from it.
4638 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4639 object_name = kmalloc(size, GFP_NOIO);
4642 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4643 dout("rbd id object name is %s\n", object_name);
4645 /* Response will be an encoded string, which includes a length */
4647 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4648 response = kzalloc(size, GFP_NOIO);
4654 /* If it doesn't exist we'll assume it's a format 1 image */
4656 ret = rbd_obj_method_sync(rbd_dev, object_name,
4657 "rbd", "get_id", NULL, 0,
4658 response, RBD_IMAGE_ID_LEN_MAX);
4659 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4660 if (ret == -ENOENT) {
4661 image_id = kstrdup("", GFP_KERNEL);
4662 ret = image_id ? 0 : -ENOMEM;
4664 rbd_dev->image_format = 1;
4665 } else if (ret > sizeof (__le32)) {
4668 image_id = ceph_extract_encoded_string(&p, p + ret,
4670 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4672 rbd_dev->image_format = 2;
4678 rbd_dev->spec->image_id = image_id;
4679 dout("image_id is %s\n", image_id);
4688 /* Undo whatever state changes are made by v1 or v2 image probe */
4690 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
4692 struct rbd_image_header *header;
4694 /* Drop parent reference unless it's already been done (or none) */
4696 if (rbd_dev->parent_overlap)
4697 rbd_dev_parent_put(rbd_dev);
4699 /* Free dynamic fields from the header, then zero it out */
4701 header = &rbd_dev->header;
4702 ceph_put_snap_context(header->snapc);
4703 kfree(header->snap_sizes);
4704 kfree(header->snap_names);
4705 kfree(header->object_prefix);
4706 memset(header, 0, sizeof (*header));
4709 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
4713 ret = rbd_dev_v2_object_prefix(rbd_dev);
4718 * Get the and check features for the image. Currently the
4719 * features are assumed to never change.
4721 ret = rbd_dev_v2_features(rbd_dev);
4725 /* If the image supports fancy striping, get its parameters */
4727 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4728 ret = rbd_dev_v2_striping_info(rbd_dev);
4732 /* No support for crypto and compression type format 2 images */
4736 rbd_dev->header.features = 0;
4737 kfree(rbd_dev->header.object_prefix);
4738 rbd_dev->header.object_prefix = NULL;
4743 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4745 struct rbd_device *parent = NULL;
4746 struct rbd_spec *parent_spec;
4747 struct rbd_client *rbdc;
4750 if (!rbd_dev->parent_spec)
4753 * We need to pass a reference to the client and the parent
4754 * spec when creating the parent rbd_dev. Images related by
4755 * parent/child relationships always share both.
4757 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4758 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4761 parent = rbd_dev_create(rbdc, parent_spec);
4765 ret = rbd_dev_image_probe(parent, false);
4768 rbd_dev->parent = parent;
4769 atomic_set(&rbd_dev->parent_ref, 1);
4774 rbd_dev_unparent(rbd_dev);
4775 kfree(rbd_dev->header_name);
4776 rbd_dev_destroy(parent);
4778 rbd_put_client(rbdc);
4779 rbd_spec_put(parent_spec);
4785 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
4789 /* generate unique id: find highest unique id, add one */
4790 rbd_dev_id_get(rbd_dev);
4792 /* Fill in the device name, now that we have its id. */
4793 BUILD_BUG_ON(DEV_NAME_LEN
4794 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4795 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4797 /* Get our block major device number. */
4799 ret = register_blkdev(0, rbd_dev->name);
4802 rbd_dev->major = ret;
4804 /* Set up the blkdev mapping. */
4806 ret = rbd_init_disk(rbd_dev);
4808 goto err_out_blkdev;
4810 ret = rbd_dev_mapping_set(rbd_dev);
4813 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4815 ret = rbd_bus_add_dev(rbd_dev);
4817 goto err_out_mapping;
4819 /* Everything's ready. Announce the disk to the world. */
4821 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4822 add_disk(rbd_dev->disk);
4824 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4825 (unsigned long long) rbd_dev->mapping.size);
4830 rbd_dev_mapping_clear(rbd_dev);
4832 rbd_free_disk(rbd_dev);
4834 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4836 rbd_dev_id_put(rbd_dev);
4837 rbd_dev_mapping_clear(rbd_dev);
4842 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
4844 struct rbd_spec *spec = rbd_dev->spec;
4847 /* Record the header object name for this rbd image. */
4849 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4851 if (rbd_dev->image_format == 1)
4852 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
4854 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
4856 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4857 if (!rbd_dev->header_name)
4860 if (rbd_dev->image_format == 1)
4861 sprintf(rbd_dev->header_name, "%s%s",
4862 spec->image_name, RBD_SUFFIX);
4864 sprintf(rbd_dev->header_name, "%s%s",
4865 RBD_HEADER_PREFIX, spec->image_id);
4869 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
4871 rbd_dev_unprobe(rbd_dev);
4872 kfree(rbd_dev->header_name);
4873 rbd_dev->header_name = NULL;
4874 rbd_dev->image_format = 0;
4875 kfree(rbd_dev->spec->image_id);
4876 rbd_dev->spec->image_id = NULL;
4878 rbd_dev_destroy(rbd_dev);
4882 * Probe for the existence of the header object for the given rbd
4883 * device. If this image is the one being mapped (i.e., not a
4884 * parent), initiate a watch on its header object before using that
4885 * object to get detailed information about the rbd image.
4887 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping)
4893 * Get the id from the image id object. If it's not a
4894 * format 2 image, we'll get ENOENT back, and we'll assume
4895 * it's a format 1 image.
4897 ret = rbd_dev_image_id(rbd_dev);
4900 rbd_assert(rbd_dev->spec->image_id);
4901 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4903 ret = rbd_dev_header_name(rbd_dev);
4905 goto err_out_format;
4908 ret = rbd_dev_header_watch_sync(rbd_dev, true);
4910 goto out_header_name;
4913 if (rbd_dev->image_format == 1)
4914 ret = rbd_dev_v1_header_info(rbd_dev);
4916 ret = rbd_dev_v2_header_info(rbd_dev);
4920 ret = rbd_dev_spec_update(rbd_dev);
4924 ret = rbd_dev_probe_parent(rbd_dev);
4928 dout("discovered format %u image, header name is %s\n",
4929 rbd_dev->image_format, rbd_dev->header_name);
4933 rbd_dev_unprobe(rbd_dev);
4936 tmp = rbd_dev_header_watch_sync(rbd_dev, false);
4938 rbd_warn(rbd_dev, "unable to tear down "
4939 "watch request (%d)\n", tmp);
4942 kfree(rbd_dev->header_name);
4943 rbd_dev->header_name = NULL;
4945 rbd_dev->image_format = 0;
4946 kfree(rbd_dev->spec->image_id);
4947 rbd_dev->spec->image_id = NULL;
4949 dout("probe failed, returning %d\n", ret);
4954 static ssize_t rbd_add(struct bus_type *bus,
4958 struct rbd_device *rbd_dev = NULL;
4959 struct ceph_options *ceph_opts = NULL;
4960 struct rbd_options *rbd_opts = NULL;
4961 struct rbd_spec *spec = NULL;
4962 struct rbd_client *rbdc;
4963 struct ceph_osd_client *osdc;
4967 if (!try_module_get(THIS_MODULE))
4970 /* parse add command */
4971 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4973 goto err_out_module;
4974 read_only = rbd_opts->read_only;
4976 rbd_opts = NULL; /* done with this */
4978 rbdc = rbd_get_client(ceph_opts);
4983 ceph_opts = NULL; /* rbd_dev client now owns this */
4986 osdc = &rbdc->client->osdc;
4987 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4989 goto err_out_client;
4990 spec->pool_id = (u64)rc;
4992 /* The ceph file layout needs to fit pool id in 32 bits */
4994 if (spec->pool_id > (u64)U32_MAX) {
4995 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4996 (unsigned long long)spec->pool_id, U32_MAX);
4998 goto err_out_client;
5001 rbd_dev = rbd_dev_create(rbdc, spec);
5003 goto err_out_client;
5004 rbdc = NULL; /* rbd_dev now owns this */
5005 spec = NULL; /* rbd_dev now owns this */
5007 rc = rbd_dev_image_probe(rbd_dev, true);
5009 goto err_out_rbd_dev;
5011 /* If we are mapping a snapshot it must be marked read-only */
5013 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
5015 rbd_dev->mapping.read_only = read_only;
5017 rc = rbd_dev_device_setup(rbd_dev);
5021 rbd_dev_image_release(rbd_dev);
5023 rbd_dev_destroy(rbd_dev);
5025 rbd_put_client(rbdc);
5028 ceph_destroy_options(ceph_opts);
5032 module_put(THIS_MODULE);
5034 dout("Error adding device %s\n", buf);
5039 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
5041 struct list_head *tmp;
5042 struct rbd_device *rbd_dev;
5044 spin_lock(&rbd_dev_list_lock);
5045 list_for_each(tmp, &rbd_dev_list) {
5046 rbd_dev = list_entry(tmp, struct rbd_device, node);
5047 if (rbd_dev->dev_id == dev_id) {
5048 spin_unlock(&rbd_dev_list_lock);
5052 spin_unlock(&rbd_dev_list_lock);
5056 static void rbd_dev_device_release(struct device *dev)
5058 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5060 rbd_free_disk(rbd_dev);
5061 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
5062 rbd_dev_mapping_clear(rbd_dev);
5063 unregister_blkdev(rbd_dev->major, rbd_dev->name);
5065 rbd_dev_id_put(rbd_dev);
5066 rbd_dev_mapping_clear(rbd_dev);
5069 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
5071 while (rbd_dev->parent) {
5072 struct rbd_device *first = rbd_dev;
5073 struct rbd_device *second = first->parent;
5074 struct rbd_device *third;
5077 * Follow to the parent with no grandparent and
5080 while (second && (third = second->parent)) {
5085 rbd_dev_image_release(second);
5086 first->parent = NULL;
5087 first->parent_overlap = 0;
5089 rbd_assert(first->parent_spec);
5090 rbd_spec_put(first->parent_spec);
5091 first->parent_spec = NULL;
5095 static ssize_t rbd_remove(struct bus_type *bus,
5099 struct rbd_device *rbd_dev = NULL;
5104 ret = strict_strtoul(buf, 10, &ul);
5108 /* convert to int; abort if we lost anything in the conversion */
5109 target_id = (int) ul;
5110 if (target_id != ul)
5113 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
5115 rbd_dev = __rbd_get_dev(target_id);
5121 spin_lock_irq(&rbd_dev->lock);
5122 if (rbd_dev->open_count)
5125 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
5126 spin_unlock_irq(&rbd_dev->lock);
5129 rbd_bus_del_dev(rbd_dev);
5130 ret = rbd_dev_header_watch_sync(rbd_dev, false);
5132 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
5133 rbd_dev_image_release(rbd_dev);
5134 module_put(THIS_MODULE);
5137 mutex_unlock(&ctl_mutex);
5143 * create control files in sysfs
5146 static int rbd_sysfs_init(void)
5150 ret = device_register(&rbd_root_dev);
5154 ret = bus_register(&rbd_bus_type);
5156 device_unregister(&rbd_root_dev);
5161 static void rbd_sysfs_cleanup(void)
5163 bus_unregister(&rbd_bus_type);
5164 device_unregister(&rbd_root_dev);
5167 static int rbd_slab_init(void)
5169 rbd_assert(!rbd_img_request_cache);
5170 rbd_img_request_cache = kmem_cache_create("rbd_img_request",
5171 sizeof (struct rbd_img_request),
5172 __alignof__(struct rbd_img_request),
5174 if (!rbd_img_request_cache)
5177 rbd_assert(!rbd_obj_request_cache);
5178 rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
5179 sizeof (struct rbd_obj_request),
5180 __alignof__(struct rbd_obj_request),
5182 if (!rbd_obj_request_cache)
5185 rbd_assert(!rbd_segment_name_cache);
5186 rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
5187 MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
5188 if (rbd_segment_name_cache)
5191 if (rbd_obj_request_cache) {
5192 kmem_cache_destroy(rbd_obj_request_cache);
5193 rbd_obj_request_cache = NULL;
5196 kmem_cache_destroy(rbd_img_request_cache);
5197 rbd_img_request_cache = NULL;
5202 static void rbd_slab_exit(void)
5204 rbd_assert(rbd_segment_name_cache);
5205 kmem_cache_destroy(rbd_segment_name_cache);
5206 rbd_segment_name_cache = NULL;
5208 rbd_assert(rbd_obj_request_cache);
5209 kmem_cache_destroy(rbd_obj_request_cache);
5210 rbd_obj_request_cache = NULL;
5212 rbd_assert(rbd_img_request_cache);
5213 kmem_cache_destroy(rbd_img_request_cache);
5214 rbd_img_request_cache = NULL;
5217 static int __init rbd_init(void)
5221 if (!libceph_compatible(NULL)) {
5222 rbd_warn(NULL, "libceph incompatibility (quitting)");
5226 rc = rbd_slab_init();
5229 rc = rbd_sysfs_init();
5233 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5238 static void __exit rbd_exit(void)
5240 rbd_sysfs_cleanup();
5244 module_init(rbd_init);
5245 module_exit(rbd_exit);
5247 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5248 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5249 MODULE_DESCRIPTION("rados block device");
5251 /* following authorship retained from original osdblk.c */
5252 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5254 MODULE_LICENSE("GPL");