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)
58 #define RBD_DRV_NAME "rbd"
59 #define RBD_DRV_NAME_LONG "rbd (rados block device)"
61 #define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
63 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
64 #define RBD_MAX_SNAP_NAME_LEN \
65 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
67 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
69 #define RBD_SNAP_HEAD_NAME "-"
71 #define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
73 /* This allows a single page to hold an image name sent by OSD */
74 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
75 #define RBD_IMAGE_ID_LEN_MAX 64
77 #define RBD_OBJ_PREFIX_LEN_MAX 64
81 #define RBD_FEATURE_LAYERING (1<<0)
82 #define RBD_FEATURE_STRIPINGV2 (1<<1)
83 #define RBD_FEATURES_ALL \
84 (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
86 /* Features supported by this (client software) implementation. */
88 #define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
91 * An RBD device name will be "rbd#", where the "rbd" comes from
92 * RBD_DRV_NAME above, and # is a unique integer identifier.
93 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
94 * enough to hold all possible device names.
96 #define DEV_NAME_LEN 32
97 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
100 * block device image metadata (in-memory version)
102 struct rbd_image_header {
103 /* These four fields never change for a given rbd image */
110 /* The remaining fields need to be updated occasionally */
112 struct ceph_snap_context *snapc;
121 * An rbd image specification.
123 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
124 * identify an image. Each rbd_dev structure includes a pointer to
125 * an rbd_spec structure that encapsulates this identity.
127 * Each of the id's in an rbd_spec has an associated name. For a
128 * user-mapped image, the names are supplied and the id's associated
129 * with them are looked up. For a layered image, a parent image is
130 * defined by the tuple, and the names are looked up.
132 * An rbd_dev structure contains a parent_spec pointer which is
133 * non-null if the image it represents is a child in a layered
134 * image. This pointer will refer to the rbd_spec structure used
135 * by the parent rbd_dev for its own identity (i.e., the structure
136 * is shared between the parent and child).
138 * Since these structures are populated once, during the discovery
139 * phase of image construction, they are effectively immutable so
140 * we make no effort to synchronize access to them.
142 * Note that code herein does not assume the image name is known (it
143 * could be a null pointer).
147 const char *pool_name;
149 const char *image_id;
150 const char *image_name;
153 const char *snap_name;
159 * an instance of the client. multiple devices may share an rbd client.
162 struct ceph_client *client;
164 struct list_head node;
167 struct rbd_img_request;
168 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
170 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
172 struct rbd_obj_request;
173 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
175 enum obj_request_type {
176 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
180 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
181 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
182 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
183 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
186 struct rbd_obj_request {
187 const char *object_name;
188 u64 offset; /* object start byte */
189 u64 length; /* bytes from offset */
193 * An object request associated with an image will have its
194 * img_data flag set; a standalone object request will not.
196 * A standalone object request will have which == BAD_WHICH
197 * and a null obj_request pointer.
199 * An object request initiated in support of a layered image
200 * object (to check for its existence before a write) will
201 * have which == BAD_WHICH and a non-null obj_request pointer.
203 * Finally, an object request for rbd image data will have
204 * which != BAD_WHICH, and will have a non-null img_request
205 * pointer. The value of which will be in the range
206 * 0..(img_request->obj_request_count-1).
209 struct rbd_obj_request *obj_request; /* STAT op */
211 struct rbd_img_request *img_request;
213 /* links for img_request->obj_requests list */
214 struct list_head links;
217 u32 which; /* posn image request list */
219 enum obj_request_type type;
221 struct bio *bio_list;
227 struct page **copyup_pages;
229 struct ceph_osd_request *osd_req;
231 u64 xferred; /* bytes transferred */
234 rbd_obj_callback_t callback;
235 struct completion completion;
241 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
242 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
243 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
246 struct rbd_img_request {
247 struct rbd_device *rbd_dev;
248 u64 offset; /* starting image byte offset */
249 u64 length; /* byte count from offset */
252 u64 snap_id; /* for reads */
253 struct ceph_snap_context *snapc; /* for writes */
256 struct request *rq; /* block request */
257 struct rbd_obj_request *obj_request; /* obj req initiator */
259 struct page **copyup_pages;
260 spinlock_t completion_lock;/* protects next_completion */
262 rbd_img_callback_t callback;
263 u64 xferred;/* aggregate bytes transferred */
264 int result; /* first nonzero obj_request result */
266 u32 obj_request_count;
267 struct list_head obj_requests; /* rbd_obj_request structs */
272 #define for_each_obj_request(ireq, oreq) \
273 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
274 #define for_each_obj_request_from(ireq, oreq) \
275 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
276 #define for_each_obj_request_safe(ireq, oreq, n) \
277 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
289 int dev_id; /* blkdev unique id */
291 int major; /* blkdev assigned major */
292 struct gendisk *disk; /* blkdev's gendisk and rq */
294 u32 image_format; /* Either 1 or 2 */
295 struct rbd_client *rbd_client;
297 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
299 spinlock_t lock; /* queue, flags, open_count */
301 struct rbd_image_header header;
302 unsigned long flags; /* possibly lock protected */
303 struct rbd_spec *spec;
307 struct ceph_file_layout layout;
309 struct ceph_osd_event *watch_event;
310 struct rbd_obj_request *watch_request;
312 struct rbd_spec *parent_spec;
314 struct rbd_device *parent;
316 /* protects updating the header */
317 struct rw_semaphore header_rwsem;
319 struct rbd_mapping mapping;
321 struct list_head node;
325 unsigned long open_count; /* protected by lock */
329 * Flag bits for rbd_dev->flags. If atomicity is required,
330 * rbd_dev->lock is used to protect access.
332 * Currently, only the "removing" flag (which is coupled with the
333 * "open_count" field) requires atomic access.
336 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
337 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
340 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
342 static LIST_HEAD(rbd_dev_list); /* devices */
343 static DEFINE_SPINLOCK(rbd_dev_list_lock);
345 static LIST_HEAD(rbd_client_list); /* clients */
346 static DEFINE_SPINLOCK(rbd_client_list_lock);
348 /* Slab caches for frequently-allocated structures */
350 static struct kmem_cache *rbd_img_request_cache;
351 static struct kmem_cache *rbd_obj_request_cache;
352 static struct kmem_cache *rbd_segment_name_cache;
354 static int rbd_img_request_submit(struct rbd_img_request *img_request);
356 static void rbd_dev_device_release(struct device *dev);
358 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
360 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
362 static int rbd_dev_image_probe(struct rbd_device *rbd_dev);
364 static struct bus_attribute rbd_bus_attrs[] = {
365 __ATTR(add, S_IWUSR, NULL, rbd_add),
366 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
370 static struct bus_type rbd_bus_type = {
372 .bus_attrs = rbd_bus_attrs,
375 static void rbd_root_dev_release(struct device *dev)
379 static struct device rbd_root_dev = {
381 .release = rbd_root_dev_release,
384 static __printf(2, 3)
385 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
387 struct va_format vaf;
395 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
396 else if (rbd_dev->disk)
397 printk(KERN_WARNING "%s: %s: %pV\n",
398 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
399 else if (rbd_dev->spec && rbd_dev->spec->image_name)
400 printk(KERN_WARNING "%s: image %s: %pV\n",
401 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
402 else if (rbd_dev->spec && rbd_dev->spec->image_id)
403 printk(KERN_WARNING "%s: id %s: %pV\n",
404 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
406 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
407 RBD_DRV_NAME, rbd_dev, &vaf);
412 #define rbd_assert(expr) \
413 if (unlikely(!(expr))) { \
414 printk(KERN_ERR "\nAssertion failure in %s() " \
416 "\trbd_assert(%s);\n\n", \
417 __func__, __LINE__, #expr); \
420 #else /* !RBD_DEBUG */
421 # define rbd_assert(expr) ((void) 0)
422 #endif /* !RBD_DEBUG */
424 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
425 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
426 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
428 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
429 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev);
430 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
432 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
433 u8 *order, u64 *snap_size);
434 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
436 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name);
438 static int rbd_open(struct block_device *bdev, fmode_t mode)
440 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
441 bool removing = false;
443 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
446 spin_lock_irq(&rbd_dev->lock);
447 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
450 rbd_dev->open_count++;
451 spin_unlock_irq(&rbd_dev->lock);
455 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
456 (void) get_device(&rbd_dev->dev);
457 set_device_ro(bdev, rbd_dev->mapping.read_only);
458 mutex_unlock(&ctl_mutex);
463 static int rbd_release(struct gendisk *disk, fmode_t mode)
465 struct rbd_device *rbd_dev = disk->private_data;
466 unsigned long open_count_before;
468 spin_lock_irq(&rbd_dev->lock);
469 open_count_before = rbd_dev->open_count--;
470 spin_unlock_irq(&rbd_dev->lock);
471 rbd_assert(open_count_before > 0);
473 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
474 put_device(&rbd_dev->dev);
475 mutex_unlock(&ctl_mutex);
480 static const struct block_device_operations rbd_bd_ops = {
481 .owner = THIS_MODULE,
483 .release = rbd_release,
487 * Initialize an rbd client instance.
490 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
492 struct rbd_client *rbdc;
495 dout("%s:\n", __func__);
496 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
500 kref_init(&rbdc->kref);
501 INIT_LIST_HEAD(&rbdc->node);
503 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
505 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
506 if (IS_ERR(rbdc->client))
508 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
510 ret = ceph_open_session(rbdc->client);
514 spin_lock(&rbd_client_list_lock);
515 list_add_tail(&rbdc->node, &rbd_client_list);
516 spin_unlock(&rbd_client_list_lock);
518 mutex_unlock(&ctl_mutex);
519 dout("%s: rbdc %p\n", __func__, rbdc);
524 ceph_destroy_client(rbdc->client);
526 mutex_unlock(&ctl_mutex);
530 ceph_destroy_options(ceph_opts);
531 dout("%s: error %d\n", __func__, ret);
536 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
538 kref_get(&rbdc->kref);
544 * Find a ceph client with specific addr and configuration. If
545 * found, bump its reference count.
547 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
549 struct rbd_client *client_node;
552 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
555 spin_lock(&rbd_client_list_lock);
556 list_for_each_entry(client_node, &rbd_client_list, node) {
557 if (!ceph_compare_options(ceph_opts, client_node->client)) {
558 __rbd_get_client(client_node);
564 spin_unlock(&rbd_client_list_lock);
566 return found ? client_node : NULL;
576 /* string args above */
579 /* Boolean args above */
583 static match_table_t rbd_opts_tokens = {
585 /* string args above */
586 {Opt_read_only, "read_only"},
587 {Opt_read_only, "ro"}, /* Alternate spelling */
588 {Opt_read_write, "read_write"},
589 {Opt_read_write, "rw"}, /* Alternate spelling */
590 /* Boolean args above */
598 #define RBD_READ_ONLY_DEFAULT false
600 static int parse_rbd_opts_token(char *c, void *private)
602 struct rbd_options *rbd_opts = private;
603 substring_t argstr[MAX_OPT_ARGS];
604 int token, intval, ret;
606 token = match_token(c, rbd_opts_tokens, argstr);
610 if (token < Opt_last_int) {
611 ret = match_int(&argstr[0], &intval);
613 pr_err("bad mount option arg (not int) "
617 dout("got int token %d val %d\n", token, intval);
618 } else if (token > Opt_last_int && token < Opt_last_string) {
619 dout("got string token %d val %s\n", token,
621 } else if (token > Opt_last_string && token < Opt_last_bool) {
622 dout("got Boolean token %d\n", token);
624 dout("got token %d\n", token);
629 rbd_opts->read_only = true;
632 rbd_opts->read_only = false;
642 * Get a ceph client with specific addr and configuration, if one does
643 * not exist create it.
645 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
647 struct rbd_client *rbdc;
649 rbdc = rbd_client_find(ceph_opts);
650 if (rbdc) /* using an existing client */
651 ceph_destroy_options(ceph_opts);
653 rbdc = rbd_client_create(ceph_opts);
659 * Destroy ceph client
661 * Caller must hold rbd_client_list_lock.
663 static void rbd_client_release(struct kref *kref)
665 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
667 dout("%s: rbdc %p\n", __func__, rbdc);
668 spin_lock(&rbd_client_list_lock);
669 list_del(&rbdc->node);
670 spin_unlock(&rbd_client_list_lock);
672 ceph_destroy_client(rbdc->client);
677 * Drop reference to ceph client node. If it's not referenced anymore, release
680 static void rbd_put_client(struct rbd_client *rbdc)
683 kref_put(&rbdc->kref, rbd_client_release);
686 static bool rbd_image_format_valid(u32 image_format)
688 return image_format == 1 || image_format == 2;
691 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
696 /* The header has to start with the magic rbd header text */
697 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
700 /* The bio layer requires at least sector-sized I/O */
702 if (ondisk->options.order < SECTOR_SHIFT)
705 /* If we use u64 in a few spots we may be able to loosen this */
707 if (ondisk->options.order > 8 * sizeof (int) - 1)
711 * The size of a snapshot header has to fit in a size_t, and
712 * that limits the number of snapshots.
714 snap_count = le32_to_cpu(ondisk->snap_count);
715 size = SIZE_MAX - sizeof (struct ceph_snap_context);
716 if (snap_count > size / sizeof (__le64))
720 * Not only that, but the size of the entire the snapshot
721 * header must also be representable in a size_t.
723 size -= snap_count * sizeof (__le64);
724 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
731 * Create a new header structure, translate header format from the on-disk
734 static int rbd_header_from_disk(struct rbd_image_header *header,
735 struct rbd_image_header_ondisk *ondisk)
742 memset(header, 0, sizeof (*header));
744 snap_count = le32_to_cpu(ondisk->snap_count);
746 len = strnlen(ondisk->object_prefix, sizeof (ondisk->object_prefix));
747 header->object_prefix = kmalloc(len + 1, GFP_KERNEL);
748 if (!header->object_prefix)
750 memcpy(header->object_prefix, ondisk->object_prefix, len);
751 header->object_prefix[len] = '\0';
754 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
756 /* Save a copy of the snapshot names */
758 if (snap_names_len > (u64) SIZE_MAX)
760 header->snap_names = kmalloc(snap_names_len, GFP_KERNEL);
761 if (!header->snap_names)
764 * Note that rbd_dev_v1_header_read() guarantees
765 * the ondisk buffer we're working with has
766 * snap_names_len bytes beyond the end of the
767 * snapshot id array, this memcpy() is safe.
769 memcpy(header->snap_names, &ondisk->snaps[snap_count],
772 /* Record each snapshot's size */
774 size = snap_count * sizeof (*header->snap_sizes);
775 header->snap_sizes = kmalloc(size, GFP_KERNEL);
776 if (!header->snap_sizes)
778 for (i = 0; i < snap_count; i++)
779 header->snap_sizes[i] =
780 le64_to_cpu(ondisk->snaps[i].image_size);
782 header->snap_names = NULL;
783 header->snap_sizes = NULL;
786 header->features = 0; /* No features support in v1 images */
787 header->obj_order = ondisk->options.order;
788 header->crypt_type = ondisk->options.crypt_type;
789 header->comp_type = ondisk->options.comp_type;
791 /* Allocate and fill in the snapshot context */
793 header->image_size = le64_to_cpu(ondisk->image_size);
795 header->snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
798 header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
799 for (i = 0; i < snap_count; i++)
800 header->snapc->snaps[i] = le64_to_cpu(ondisk->snaps[i].id);
805 kfree(header->snap_sizes);
806 header->snap_sizes = NULL;
807 kfree(header->snap_names);
808 header->snap_names = NULL;
809 kfree(header->object_prefix);
810 header->object_prefix = NULL;
815 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
817 const char *snap_name;
819 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
821 /* Skip over names until we find the one we are looking for */
823 snap_name = rbd_dev->header.snap_names;
825 snap_name += strlen(snap_name) + 1;
827 return kstrdup(snap_name, GFP_KERNEL);
831 * Snapshot id comparison function for use with qsort()/bsearch().
832 * Note that result is for snapshots in *descending* order.
834 static int snapid_compare_reverse(const void *s1, const void *s2)
836 u64 snap_id1 = *(u64 *)s1;
837 u64 snap_id2 = *(u64 *)s2;
839 if (snap_id1 < snap_id2)
841 return snap_id1 == snap_id2 ? 0 : -1;
845 * Search a snapshot context to see if the given snapshot id is
848 * Returns the position of the snapshot id in the array if it's found,
849 * or BAD_SNAP_INDEX otherwise.
851 * Note: The snapshot array is in kept sorted (by the osd) in
852 * reverse order, highest snapshot id first.
854 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
856 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
859 found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
860 sizeof (snap_id), snapid_compare_reverse);
862 return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
865 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
870 which = rbd_dev_snap_index(rbd_dev, snap_id);
871 if (which == BAD_SNAP_INDEX)
874 return _rbd_dev_v1_snap_name(rbd_dev, which);
877 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
879 if (snap_id == CEPH_NOSNAP)
880 return RBD_SNAP_HEAD_NAME;
882 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
883 if (rbd_dev->image_format == 1)
884 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
886 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
889 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
892 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
893 if (snap_id == CEPH_NOSNAP) {
894 *snap_size = rbd_dev->header.image_size;
895 } else if (rbd_dev->image_format == 1) {
898 which = rbd_dev_snap_index(rbd_dev, snap_id);
899 if (which == BAD_SNAP_INDEX)
902 *snap_size = rbd_dev->header.snap_sizes[which];
907 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
916 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
919 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
920 if (snap_id == CEPH_NOSNAP) {
921 *snap_features = rbd_dev->header.features;
922 } else if (rbd_dev->image_format == 1) {
923 *snap_features = 0; /* No features for format 1 */
928 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
932 *snap_features = features;
937 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
939 const char *snap_name = rbd_dev->spec->snap_name;
945 if (strcmp(snap_name, RBD_SNAP_HEAD_NAME)) {
946 snap_id = rbd_snap_id_by_name(rbd_dev, snap_name);
947 if (snap_id == CEPH_NOSNAP)
950 snap_id = CEPH_NOSNAP;
953 ret = rbd_snap_size(rbd_dev, snap_id, &size);
956 ret = rbd_snap_features(rbd_dev, snap_id, &features);
960 rbd_dev->mapping.size = size;
961 rbd_dev->mapping.features = features;
963 /* If we are mapping a snapshot it must be marked read-only */
965 if (snap_id != CEPH_NOSNAP)
966 rbd_dev->mapping.read_only = true;
971 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
973 rbd_dev->mapping.size = 0;
974 rbd_dev->mapping.features = 0;
975 rbd_dev->mapping.read_only = true;
978 static void rbd_dev_clear_mapping(struct rbd_device *rbd_dev)
980 rbd_dev->mapping.size = 0;
981 rbd_dev->mapping.features = 0;
982 rbd_dev->mapping.read_only = true;
985 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
991 name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
994 segment = offset >> rbd_dev->header.obj_order;
995 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
996 rbd_dev->header.object_prefix, segment);
997 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
998 pr_err("error formatting segment name for #%llu (%d)\n",
1007 static void rbd_segment_name_free(const char *name)
1009 /* The explicit cast here is needed to drop the const qualifier */
1011 kmem_cache_free(rbd_segment_name_cache, (void *)name);
1014 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1016 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1018 return offset & (segment_size - 1);
1021 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1022 u64 offset, u64 length)
1024 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1026 offset &= segment_size - 1;
1028 rbd_assert(length <= U64_MAX - offset);
1029 if (offset + length > segment_size)
1030 length = segment_size - offset;
1036 * returns the size of an object in the image
1038 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1040 return 1 << header->obj_order;
1047 static void bio_chain_put(struct bio *chain)
1053 chain = chain->bi_next;
1059 * zeros a bio chain, starting at specific offset
1061 static void zero_bio_chain(struct bio *chain, int start_ofs)
1064 unsigned long flags;
1070 bio_for_each_segment(bv, chain, i) {
1071 if (pos + bv->bv_len > start_ofs) {
1072 int remainder = max(start_ofs - pos, 0);
1073 buf = bvec_kmap_irq(bv, &flags);
1074 memset(buf + remainder, 0,
1075 bv->bv_len - remainder);
1076 bvec_kunmap_irq(buf, &flags);
1081 chain = chain->bi_next;
1086 * similar to zero_bio_chain(), zeros data defined by a page array,
1087 * starting at the given byte offset from the start of the array and
1088 * continuing up to the given end offset. The pages array is
1089 * assumed to be big enough to hold all bytes up to the end.
1091 static void zero_pages(struct page **pages, u64 offset, u64 end)
1093 struct page **page = &pages[offset >> PAGE_SHIFT];
1095 rbd_assert(end > offset);
1096 rbd_assert(end - offset <= (u64)SIZE_MAX);
1097 while (offset < end) {
1100 unsigned long flags;
1103 page_offset = (size_t)(offset & ~PAGE_MASK);
1104 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1105 local_irq_save(flags);
1106 kaddr = kmap_atomic(*page);
1107 memset(kaddr + page_offset, 0, length);
1108 kunmap_atomic(kaddr);
1109 local_irq_restore(flags);
1117 * Clone a portion of a bio, starting at the given byte offset
1118 * and continuing for the number of bytes indicated.
1120 static struct bio *bio_clone_range(struct bio *bio_src,
1121 unsigned int offset,
1129 unsigned short end_idx;
1130 unsigned short vcnt;
1133 /* Handle the easy case for the caller */
1135 if (!offset && len == bio_src->bi_size)
1136 return bio_clone(bio_src, gfpmask);
1138 if (WARN_ON_ONCE(!len))
1140 if (WARN_ON_ONCE(len > bio_src->bi_size))
1142 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1145 /* Find first affected segment... */
1148 __bio_for_each_segment(bv, bio_src, idx, 0) {
1149 if (resid < bv->bv_len)
1151 resid -= bv->bv_len;
1155 /* ...and the last affected segment */
1158 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1159 if (resid <= bv->bv_len)
1161 resid -= bv->bv_len;
1163 vcnt = end_idx - idx + 1;
1165 /* Build the clone */
1167 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1169 return NULL; /* ENOMEM */
1171 bio->bi_bdev = bio_src->bi_bdev;
1172 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1173 bio->bi_rw = bio_src->bi_rw;
1174 bio->bi_flags |= 1 << BIO_CLONED;
1177 * Copy over our part of the bio_vec, then update the first
1178 * and last (or only) entries.
1180 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1181 vcnt * sizeof (struct bio_vec));
1182 bio->bi_io_vec[0].bv_offset += voff;
1184 bio->bi_io_vec[0].bv_len -= voff;
1185 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1187 bio->bi_io_vec[0].bv_len = len;
1190 bio->bi_vcnt = vcnt;
1198 * Clone a portion of a bio chain, starting at the given byte offset
1199 * into the first bio in the source chain and continuing for the
1200 * number of bytes indicated. The result is another bio chain of
1201 * exactly the given length, or a null pointer on error.
1203 * The bio_src and offset parameters are both in-out. On entry they
1204 * refer to the first source bio and the offset into that bio where
1205 * the start of data to be cloned is located.
1207 * On return, bio_src is updated to refer to the bio in the source
1208 * chain that contains first un-cloned byte, and *offset will
1209 * contain the offset of that byte within that bio.
1211 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1212 unsigned int *offset,
1216 struct bio *bi = *bio_src;
1217 unsigned int off = *offset;
1218 struct bio *chain = NULL;
1221 /* Build up a chain of clone bios up to the limit */
1223 if (!bi || off >= bi->bi_size || !len)
1224 return NULL; /* Nothing to clone */
1228 unsigned int bi_size;
1232 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1233 goto out_err; /* EINVAL; ran out of bio's */
1235 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1236 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1238 goto out_err; /* ENOMEM */
1241 end = &bio->bi_next;
1244 if (off == bi->bi_size) {
1255 bio_chain_put(chain);
1261 * The default/initial value for all object request flags is 0. For
1262 * each flag, once its value is set to 1 it is never reset to 0
1265 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1267 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1268 struct rbd_device *rbd_dev;
1270 rbd_dev = obj_request->img_request->rbd_dev;
1271 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1276 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1279 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1282 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1284 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1285 struct rbd_device *rbd_dev = NULL;
1287 if (obj_request_img_data_test(obj_request))
1288 rbd_dev = obj_request->img_request->rbd_dev;
1289 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1294 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1297 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1301 * This sets the KNOWN flag after (possibly) setting the EXISTS
1302 * flag. The latter is set based on the "exists" value provided.
1304 * Note that for our purposes once an object exists it never goes
1305 * away again. It's possible that the response from two existence
1306 * checks are separated by the creation of the target object, and
1307 * the first ("doesn't exist") response arrives *after* the second
1308 * ("does exist"). In that case we ignore the second one.
1310 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1314 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1315 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1319 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1322 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1325 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1328 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1331 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1333 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1334 atomic_read(&obj_request->kref.refcount));
1335 kref_get(&obj_request->kref);
1338 static void rbd_obj_request_destroy(struct kref *kref);
1339 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1341 rbd_assert(obj_request != NULL);
1342 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1343 atomic_read(&obj_request->kref.refcount));
1344 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1347 static void rbd_img_request_get(struct rbd_img_request *img_request)
1349 dout("%s: img %p (was %d)\n", __func__, img_request,
1350 atomic_read(&img_request->kref.refcount));
1351 kref_get(&img_request->kref);
1354 static void rbd_img_request_destroy(struct kref *kref);
1355 static void rbd_img_request_put(struct rbd_img_request *img_request)
1357 rbd_assert(img_request != NULL);
1358 dout("%s: img %p (was %d)\n", __func__, img_request,
1359 atomic_read(&img_request->kref.refcount));
1360 kref_put(&img_request->kref, rbd_img_request_destroy);
1363 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1364 struct rbd_obj_request *obj_request)
1366 rbd_assert(obj_request->img_request == NULL);
1368 /* Image request now owns object's original reference */
1369 obj_request->img_request = img_request;
1370 obj_request->which = img_request->obj_request_count;
1371 rbd_assert(!obj_request_img_data_test(obj_request));
1372 obj_request_img_data_set(obj_request);
1373 rbd_assert(obj_request->which != BAD_WHICH);
1374 img_request->obj_request_count++;
1375 list_add_tail(&obj_request->links, &img_request->obj_requests);
1376 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1377 obj_request->which);
1380 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1381 struct rbd_obj_request *obj_request)
1383 rbd_assert(obj_request->which != BAD_WHICH);
1385 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1386 obj_request->which);
1387 list_del(&obj_request->links);
1388 rbd_assert(img_request->obj_request_count > 0);
1389 img_request->obj_request_count--;
1390 rbd_assert(obj_request->which == img_request->obj_request_count);
1391 obj_request->which = BAD_WHICH;
1392 rbd_assert(obj_request_img_data_test(obj_request));
1393 rbd_assert(obj_request->img_request == img_request);
1394 obj_request->img_request = NULL;
1395 obj_request->callback = NULL;
1396 rbd_obj_request_put(obj_request);
1399 static bool obj_request_type_valid(enum obj_request_type type)
1402 case OBJ_REQUEST_NODATA:
1403 case OBJ_REQUEST_BIO:
1404 case OBJ_REQUEST_PAGES:
1411 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1412 struct rbd_obj_request *obj_request)
1414 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1416 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1419 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1422 dout("%s: img %p\n", __func__, img_request);
1425 * If no error occurred, compute the aggregate transfer
1426 * count for the image request. We could instead use
1427 * atomic64_cmpxchg() to update it as each object request
1428 * completes; not clear which way is better off hand.
1430 if (!img_request->result) {
1431 struct rbd_obj_request *obj_request;
1434 for_each_obj_request(img_request, obj_request)
1435 xferred += obj_request->xferred;
1436 img_request->xferred = xferred;
1439 if (img_request->callback)
1440 img_request->callback(img_request);
1442 rbd_img_request_put(img_request);
1445 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1447 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1449 dout("%s: obj %p\n", __func__, obj_request);
1451 return wait_for_completion_interruptible(&obj_request->completion);
1455 * The default/initial value for all image request flags is 0. Each
1456 * is conditionally set to 1 at image request initialization time
1457 * and currently never change thereafter.
1459 static void img_request_write_set(struct rbd_img_request *img_request)
1461 set_bit(IMG_REQ_WRITE, &img_request->flags);
1465 static bool img_request_write_test(struct rbd_img_request *img_request)
1468 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1471 static void img_request_child_set(struct rbd_img_request *img_request)
1473 set_bit(IMG_REQ_CHILD, &img_request->flags);
1477 static bool img_request_child_test(struct rbd_img_request *img_request)
1480 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1483 static void img_request_layered_set(struct rbd_img_request *img_request)
1485 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1489 static bool img_request_layered_test(struct rbd_img_request *img_request)
1492 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1496 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1498 u64 xferred = obj_request->xferred;
1499 u64 length = obj_request->length;
1501 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1502 obj_request, obj_request->img_request, obj_request->result,
1505 * ENOENT means a hole in the image. We zero-fill the
1506 * entire length of the request. A short read also implies
1507 * zero-fill to the end of the request. Either way we
1508 * update the xferred count to indicate the whole request
1511 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1512 if (obj_request->result == -ENOENT) {
1513 if (obj_request->type == OBJ_REQUEST_BIO)
1514 zero_bio_chain(obj_request->bio_list, 0);
1516 zero_pages(obj_request->pages, 0, length);
1517 obj_request->result = 0;
1518 obj_request->xferred = length;
1519 } else if (xferred < length && !obj_request->result) {
1520 if (obj_request->type == OBJ_REQUEST_BIO)
1521 zero_bio_chain(obj_request->bio_list, xferred);
1523 zero_pages(obj_request->pages, xferred, length);
1524 obj_request->xferred = length;
1526 obj_request_done_set(obj_request);
1529 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1531 dout("%s: obj %p cb %p\n", __func__, obj_request,
1532 obj_request->callback);
1533 if (obj_request->callback)
1534 obj_request->callback(obj_request);
1536 complete_all(&obj_request->completion);
1539 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1541 dout("%s: obj %p\n", __func__, obj_request);
1542 obj_request_done_set(obj_request);
1545 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1547 struct rbd_img_request *img_request = NULL;
1548 struct rbd_device *rbd_dev = NULL;
1549 bool layered = false;
1551 if (obj_request_img_data_test(obj_request)) {
1552 img_request = obj_request->img_request;
1553 layered = img_request && img_request_layered_test(img_request);
1554 rbd_dev = img_request->rbd_dev;
1557 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1558 obj_request, img_request, obj_request->result,
1559 obj_request->xferred, obj_request->length);
1560 if (layered && obj_request->result == -ENOENT &&
1561 obj_request->img_offset < rbd_dev->parent_overlap)
1562 rbd_img_parent_read(obj_request);
1563 else if (img_request)
1564 rbd_img_obj_request_read_callback(obj_request);
1566 obj_request_done_set(obj_request);
1569 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1571 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1572 obj_request->result, obj_request->length);
1574 * There is no such thing as a successful short write. Set
1575 * it to our originally-requested length.
1577 obj_request->xferred = obj_request->length;
1578 obj_request_done_set(obj_request);
1582 * For a simple stat call there's nothing to do. We'll do more if
1583 * this is part of a write sequence for a layered image.
1585 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1587 dout("%s: obj %p\n", __func__, obj_request);
1588 obj_request_done_set(obj_request);
1591 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1592 struct ceph_msg *msg)
1594 struct rbd_obj_request *obj_request = osd_req->r_priv;
1597 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1598 rbd_assert(osd_req == obj_request->osd_req);
1599 if (obj_request_img_data_test(obj_request)) {
1600 rbd_assert(obj_request->img_request);
1601 rbd_assert(obj_request->which != BAD_WHICH);
1603 rbd_assert(obj_request->which == BAD_WHICH);
1606 if (osd_req->r_result < 0)
1607 obj_request->result = osd_req->r_result;
1609 BUG_ON(osd_req->r_num_ops > 2);
1612 * We support a 64-bit length, but ultimately it has to be
1613 * passed to blk_end_request(), which takes an unsigned int.
1615 obj_request->xferred = osd_req->r_reply_op_len[0];
1616 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1617 opcode = osd_req->r_ops[0].op;
1619 case CEPH_OSD_OP_READ:
1620 rbd_osd_read_callback(obj_request);
1622 case CEPH_OSD_OP_WRITE:
1623 rbd_osd_write_callback(obj_request);
1625 case CEPH_OSD_OP_STAT:
1626 rbd_osd_stat_callback(obj_request);
1628 case CEPH_OSD_OP_CALL:
1629 case CEPH_OSD_OP_NOTIFY_ACK:
1630 case CEPH_OSD_OP_WATCH:
1631 rbd_osd_trivial_callback(obj_request);
1634 rbd_warn(NULL, "%s: unsupported op %hu\n",
1635 obj_request->object_name, (unsigned short) opcode);
1639 if (obj_request_done_test(obj_request))
1640 rbd_obj_request_complete(obj_request);
1643 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1645 struct rbd_img_request *img_request = obj_request->img_request;
1646 struct ceph_osd_request *osd_req = obj_request->osd_req;
1649 rbd_assert(osd_req != NULL);
1651 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1652 ceph_osdc_build_request(osd_req, obj_request->offset,
1653 NULL, snap_id, NULL);
1656 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1658 struct rbd_img_request *img_request = obj_request->img_request;
1659 struct ceph_osd_request *osd_req = obj_request->osd_req;
1660 struct ceph_snap_context *snapc;
1661 struct timespec mtime = CURRENT_TIME;
1663 rbd_assert(osd_req != NULL);
1665 snapc = img_request ? img_request->snapc : NULL;
1666 ceph_osdc_build_request(osd_req, obj_request->offset,
1667 snapc, CEPH_NOSNAP, &mtime);
1670 static struct ceph_osd_request *rbd_osd_req_create(
1671 struct rbd_device *rbd_dev,
1673 struct rbd_obj_request *obj_request)
1675 struct ceph_snap_context *snapc = NULL;
1676 struct ceph_osd_client *osdc;
1677 struct ceph_osd_request *osd_req;
1679 if (obj_request_img_data_test(obj_request)) {
1680 struct rbd_img_request *img_request = obj_request->img_request;
1682 rbd_assert(write_request ==
1683 img_request_write_test(img_request));
1685 snapc = img_request->snapc;
1688 /* Allocate and initialize the request, for the single op */
1690 osdc = &rbd_dev->rbd_client->client->osdc;
1691 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1693 return NULL; /* ENOMEM */
1696 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1698 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1700 osd_req->r_callback = rbd_osd_req_callback;
1701 osd_req->r_priv = obj_request;
1703 osd_req->r_oid_len = strlen(obj_request->object_name);
1704 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1705 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1707 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1713 * Create a copyup osd request based on the information in the
1714 * object request supplied. A copyup request has two osd ops,
1715 * a copyup method call, and a "normal" write request.
1717 static struct ceph_osd_request *
1718 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1720 struct rbd_img_request *img_request;
1721 struct ceph_snap_context *snapc;
1722 struct rbd_device *rbd_dev;
1723 struct ceph_osd_client *osdc;
1724 struct ceph_osd_request *osd_req;
1726 rbd_assert(obj_request_img_data_test(obj_request));
1727 img_request = obj_request->img_request;
1728 rbd_assert(img_request);
1729 rbd_assert(img_request_write_test(img_request));
1731 /* Allocate and initialize the request, for the two ops */
1733 snapc = img_request->snapc;
1734 rbd_dev = img_request->rbd_dev;
1735 osdc = &rbd_dev->rbd_client->client->osdc;
1736 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1738 return NULL; /* ENOMEM */
1740 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1741 osd_req->r_callback = rbd_osd_req_callback;
1742 osd_req->r_priv = obj_request;
1744 osd_req->r_oid_len = strlen(obj_request->object_name);
1745 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1746 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1748 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1754 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1756 ceph_osdc_put_request(osd_req);
1759 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1761 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1762 u64 offset, u64 length,
1763 enum obj_request_type type)
1765 struct rbd_obj_request *obj_request;
1769 rbd_assert(obj_request_type_valid(type));
1771 size = strlen(object_name) + 1;
1772 name = kmalloc(size, GFP_KERNEL);
1776 obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
1782 obj_request->object_name = memcpy(name, object_name, size);
1783 obj_request->offset = offset;
1784 obj_request->length = length;
1785 obj_request->flags = 0;
1786 obj_request->which = BAD_WHICH;
1787 obj_request->type = type;
1788 INIT_LIST_HEAD(&obj_request->links);
1789 init_completion(&obj_request->completion);
1790 kref_init(&obj_request->kref);
1792 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1793 offset, length, (int)type, obj_request);
1798 static void rbd_obj_request_destroy(struct kref *kref)
1800 struct rbd_obj_request *obj_request;
1802 obj_request = container_of(kref, struct rbd_obj_request, kref);
1804 dout("%s: obj %p\n", __func__, obj_request);
1806 rbd_assert(obj_request->img_request == NULL);
1807 rbd_assert(obj_request->which == BAD_WHICH);
1809 if (obj_request->osd_req)
1810 rbd_osd_req_destroy(obj_request->osd_req);
1812 rbd_assert(obj_request_type_valid(obj_request->type));
1813 switch (obj_request->type) {
1814 case OBJ_REQUEST_NODATA:
1815 break; /* Nothing to do */
1816 case OBJ_REQUEST_BIO:
1817 if (obj_request->bio_list)
1818 bio_chain_put(obj_request->bio_list);
1820 case OBJ_REQUEST_PAGES:
1821 if (obj_request->pages)
1822 ceph_release_page_vector(obj_request->pages,
1823 obj_request->page_count);
1827 kfree(obj_request->object_name);
1828 obj_request->object_name = NULL;
1829 kmem_cache_free(rbd_obj_request_cache, obj_request);
1833 * Caller is responsible for filling in the list of object requests
1834 * that comprises the image request, and the Linux request pointer
1835 * (if there is one).
1837 static struct rbd_img_request *rbd_img_request_create(
1838 struct rbd_device *rbd_dev,
1839 u64 offset, u64 length,
1843 struct rbd_img_request *img_request;
1845 img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_ATOMIC);
1849 if (write_request) {
1850 down_read(&rbd_dev->header_rwsem);
1851 ceph_get_snap_context(rbd_dev->header.snapc);
1852 up_read(&rbd_dev->header_rwsem);
1855 img_request->rq = NULL;
1856 img_request->rbd_dev = rbd_dev;
1857 img_request->offset = offset;
1858 img_request->length = length;
1859 img_request->flags = 0;
1860 if (write_request) {
1861 img_request_write_set(img_request);
1862 img_request->snapc = rbd_dev->header.snapc;
1864 img_request->snap_id = rbd_dev->spec->snap_id;
1867 img_request_child_set(img_request);
1868 if (rbd_dev->parent_spec)
1869 img_request_layered_set(img_request);
1870 spin_lock_init(&img_request->completion_lock);
1871 img_request->next_completion = 0;
1872 img_request->callback = NULL;
1873 img_request->result = 0;
1874 img_request->obj_request_count = 0;
1875 INIT_LIST_HEAD(&img_request->obj_requests);
1876 kref_init(&img_request->kref);
1878 rbd_img_request_get(img_request); /* Avoid a warning */
1879 rbd_img_request_put(img_request); /* TEMPORARY */
1881 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1882 write_request ? "write" : "read", offset, length,
1888 static void rbd_img_request_destroy(struct kref *kref)
1890 struct rbd_img_request *img_request;
1891 struct rbd_obj_request *obj_request;
1892 struct rbd_obj_request *next_obj_request;
1894 img_request = container_of(kref, struct rbd_img_request, kref);
1896 dout("%s: img %p\n", __func__, img_request);
1898 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1899 rbd_img_obj_request_del(img_request, obj_request);
1900 rbd_assert(img_request->obj_request_count == 0);
1902 if (img_request_write_test(img_request))
1903 ceph_put_snap_context(img_request->snapc);
1905 if (img_request_child_test(img_request))
1906 rbd_obj_request_put(img_request->obj_request);
1908 kmem_cache_free(rbd_img_request_cache, img_request);
1911 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
1913 struct rbd_img_request *img_request;
1914 unsigned int xferred;
1918 rbd_assert(obj_request_img_data_test(obj_request));
1919 img_request = obj_request->img_request;
1921 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
1922 xferred = (unsigned int)obj_request->xferred;
1923 result = obj_request->result;
1925 struct rbd_device *rbd_dev = img_request->rbd_dev;
1927 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
1928 img_request_write_test(img_request) ? "write" : "read",
1929 obj_request->length, obj_request->img_offset,
1930 obj_request->offset);
1931 rbd_warn(rbd_dev, " result %d xferred %x\n",
1933 if (!img_request->result)
1934 img_request->result = result;
1937 /* Image object requests don't own their page array */
1939 if (obj_request->type == OBJ_REQUEST_PAGES) {
1940 obj_request->pages = NULL;
1941 obj_request->page_count = 0;
1944 if (img_request_child_test(img_request)) {
1945 rbd_assert(img_request->obj_request != NULL);
1946 more = obj_request->which < img_request->obj_request_count - 1;
1948 rbd_assert(img_request->rq != NULL);
1949 more = blk_end_request(img_request->rq, result, xferred);
1955 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1957 struct rbd_img_request *img_request;
1958 u32 which = obj_request->which;
1961 rbd_assert(obj_request_img_data_test(obj_request));
1962 img_request = obj_request->img_request;
1964 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1965 rbd_assert(img_request != NULL);
1966 rbd_assert(img_request->obj_request_count > 0);
1967 rbd_assert(which != BAD_WHICH);
1968 rbd_assert(which < img_request->obj_request_count);
1969 rbd_assert(which >= img_request->next_completion);
1971 spin_lock_irq(&img_request->completion_lock);
1972 if (which != img_request->next_completion)
1975 for_each_obj_request_from(img_request, obj_request) {
1977 rbd_assert(which < img_request->obj_request_count);
1979 if (!obj_request_done_test(obj_request))
1981 more = rbd_img_obj_end_request(obj_request);
1985 rbd_assert(more ^ (which == img_request->obj_request_count));
1986 img_request->next_completion = which;
1988 spin_unlock_irq(&img_request->completion_lock);
1991 rbd_img_request_complete(img_request);
1995 * Split up an image request into one or more object requests, each
1996 * to a different object. The "type" parameter indicates whether
1997 * "data_desc" is the pointer to the head of a list of bio
1998 * structures, or the base of a page array. In either case this
1999 * function assumes data_desc describes memory sufficient to hold
2000 * all data described by the image request.
2002 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2003 enum obj_request_type type,
2006 struct rbd_device *rbd_dev = img_request->rbd_dev;
2007 struct rbd_obj_request *obj_request = NULL;
2008 struct rbd_obj_request *next_obj_request;
2009 bool write_request = img_request_write_test(img_request);
2010 struct bio *bio_list;
2011 unsigned int bio_offset = 0;
2012 struct page **pages;
2017 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2018 (int)type, data_desc);
2020 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
2021 img_offset = img_request->offset;
2022 resid = img_request->length;
2023 rbd_assert(resid > 0);
2025 if (type == OBJ_REQUEST_BIO) {
2026 bio_list = data_desc;
2027 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
2029 rbd_assert(type == OBJ_REQUEST_PAGES);
2034 struct ceph_osd_request *osd_req;
2035 const char *object_name;
2039 object_name = rbd_segment_name(rbd_dev, img_offset);
2042 offset = rbd_segment_offset(rbd_dev, img_offset);
2043 length = rbd_segment_length(rbd_dev, img_offset, resid);
2044 obj_request = rbd_obj_request_create(object_name,
2045 offset, length, type);
2046 /* object request has its own copy of the object name */
2047 rbd_segment_name_free(object_name);
2051 if (type == OBJ_REQUEST_BIO) {
2052 unsigned int clone_size;
2054 rbd_assert(length <= (u64)UINT_MAX);
2055 clone_size = (unsigned int)length;
2056 obj_request->bio_list =
2057 bio_chain_clone_range(&bio_list,
2061 if (!obj_request->bio_list)
2064 unsigned int page_count;
2066 obj_request->pages = pages;
2067 page_count = (u32)calc_pages_for(offset, length);
2068 obj_request->page_count = page_count;
2069 if ((offset + length) & ~PAGE_MASK)
2070 page_count--; /* more on last page */
2071 pages += page_count;
2074 osd_req = rbd_osd_req_create(rbd_dev, write_request,
2078 obj_request->osd_req = osd_req;
2079 obj_request->callback = rbd_img_obj_callback;
2081 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
2083 if (type == OBJ_REQUEST_BIO)
2084 osd_req_op_extent_osd_data_bio(osd_req, 0,
2085 obj_request->bio_list, length);
2087 osd_req_op_extent_osd_data_pages(osd_req, 0,
2088 obj_request->pages, length,
2089 offset & ~PAGE_MASK, false, false);
2092 rbd_osd_req_format_write(obj_request);
2094 rbd_osd_req_format_read(obj_request);
2096 obj_request->img_offset = img_offset;
2097 rbd_img_obj_request_add(img_request, obj_request);
2099 img_offset += length;
2106 rbd_obj_request_put(obj_request);
2108 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2109 rbd_obj_request_put(obj_request);
2115 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2117 struct rbd_img_request *img_request;
2118 struct rbd_device *rbd_dev;
2122 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2123 rbd_assert(obj_request_img_data_test(obj_request));
2124 img_request = obj_request->img_request;
2125 rbd_assert(img_request);
2127 rbd_dev = img_request->rbd_dev;
2128 rbd_assert(rbd_dev);
2129 length = (u64)1 << rbd_dev->header.obj_order;
2130 page_count = (u32)calc_pages_for(0, length);
2132 rbd_assert(obj_request->copyup_pages);
2133 ceph_release_page_vector(obj_request->copyup_pages, page_count);
2134 obj_request->copyup_pages = NULL;
2137 * We want the transfer count to reflect the size of the
2138 * original write request. There is no such thing as a
2139 * successful short write, so if the request was successful
2140 * we can just set it to the originally-requested length.
2142 if (!obj_request->result)
2143 obj_request->xferred = obj_request->length;
2145 /* Finish up with the normal image object callback */
2147 rbd_img_obj_callback(obj_request);
2151 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2153 struct rbd_obj_request *orig_request;
2154 struct ceph_osd_request *osd_req;
2155 struct ceph_osd_client *osdc;
2156 struct rbd_device *rbd_dev;
2157 struct page **pages;
2162 rbd_assert(img_request_child_test(img_request));
2164 /* First get what we need from the image request */
2166 pages = img_request->copyup_pages;
2167 rbd_assert(pages != NULL);
2168 img_request->copyup_pages = NULL;
2170 orig_request = img_request->obj_request;
2171 rbd_assert(orig_request != NULL);
2172 rbd_assert(orig_request->type == OBJ_REQUEST_BIO);
2173 result = img_request->result;
2174 obj_size = img_request->length;
2175 xferred = img_request->xferred;
2177 rbd_dev = img_request->rbd_dev;
2178 rbd_assert(rbd_dev);
2179 rbd_assert(obj_size == (u64)1 << rbd_dev->header.obj_order);
2181 rbd_img_request_put(img_request);
2186 /* Allocate the new copyup osd request for the original request */
2189 rbd_assert(!orig_request->osd_req);
2190 osd_req = rbd_osd_req_create_copyup(orig_request);
2193 orig_request->osd_req = osd_req;
2194 orig_request->copyup_pages = pages;
2196 /* Initialize the copyup op */
2198 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2199 osd_req_op_cls_request_data_pages(osd_req, 0, pages, obj_size, 0,
2202 /* Then the original write request op */
2204 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2205 orig_request->offset,
2206 orig_request->length, 0, 0);
2207 osd_req_op_extent_osd_data_bio(osd_req, 1, orig_request->bio_list,
2208 orig_request->length);
2210 rbd_osd_req_format_write(orig_request);
2212 /* All set, send it off. */
2214 orig_request->callback = rbd_img_obj_copyup_callback;
2215 osdc = &rbd_dev->rbd_client->client->osdc;
2216 result = rbd_obj_request_submit(osdc, orig_request);
2220 /* Record the error code and complete the request */
2222 orig_request->result = result;
2223 orig_request->xferred = 0;
2224 obj_request_done_set(orig_request);
2225 rbd_obj_request_complete(orig_request);
2229 * Read from the parent image the range of data that covers the
2230 * entire target of the given object request. This is used for
2231 * satisfying a layered image write request when the target of an
2232 * object request from the image request does not exist.
2234 * A page array big enough to hold the returned data is allocated
2235 * and supplied to rbd_img_request_fill() as the "data descriptor."
2236 * When the read completes, this page array will be transferred to
2237 * the original object request for the copyup operation.
2239 * If an error occurs, record it as the result of the original
2240 * object request and mark it done so it gets completed.
2242 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2244 struct rbd_img_request *img_request = NULL;
2245 struct rbd_img_request *parent_request = NULL;
2246 struct rbd_device *rbd_dev;
2249 struct page **pages = NULL;
2253 rbd_assert(obj_request_img_data_test(obj_request));
2254 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2256 img_request = obj_request->img_request;
2257 rbd_assert(img_request != NULL);
2258 rbd_dev = img_request->rbd_dev;
2259 rbd_assert(rbd_dev->parent != NULL);
2262 * First things first. The original osd request is of no
2263 * use to use any more, we'll need a new one that can hold
2264 * the two ops in a copyup request. We'll get that later,
2265 * but for now we can release the old one.
2267 rbd_osd_req_destroy(obj_request->osd_req);
2268 obj_request->osd_req = NULL;
2271 * Determine the byte range covered by the object in the
2272 * child image to which the original request was to be sent.
2274 img_offset = obj_request->img_offset - obj_request->offset;
2275 length = (u64)1 << rbd_dev->header.obj_order;
2278 * There is no defined parent data beyond the parent
2279 * overlap, so limit what we read at that boundary if
2282 if (img_offset + length > rbd_dev->parent_overlap) {
2283 rbd_assert(img_offset < rbd_dev->parent_overlap);
2284 length = rbd_dev->parent_overlap - img_offset;
2288 * Allocate a page array big enough to receive the data read
2291 page_count = (u32)calc_pages_for(0, length);
2292 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2293 if (IS_ERR(pages)) {
2294 result = PTR_ERR(pages);
2300 parent_request = rbd_img_request_create(rbd_dev->parent,
2303 if (!parent_request)
2305 rbd_obj_request_get(obj_request);
2306 parent_request->obj_request = obj_request;
2308 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2311 parent_request->copyup_pages = pages;
2313 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2314 result = rbd_img_request_submit(parent_request);
2318 parent_request->copyup_pages = NULL;
2319 parent_request->obj_request = NULL;
2320 rbd_obj_request_put(obj_request);
2323 ceph_release_page_vector(pages, page_count);
2325 rbd_img_request_put(parent_request);
2326 obj_request->result = result;
2327 obj_request->xferred = 0;
2328 obj_request_done_set(obj_request);
2333 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2335 struct rbd_obj_request *orig_request;
2338 rbd_assert(!obj_request_img_data_test(obj_request));
2341 * All we need from the object request is the original
2342 * request and the result of the STAT op. Grab those, then
2343 * we're done with the request.
2345 orig_request = obj_request->obj_request;
2346 obj_request->obj_request = NULL;
2347 rbd_assert(orig_request);
2348 rbd_assert(orig_request->img_request);
2350 result = obj_request->result;
2351 obj_request->result = 0;
2353 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2354 obj_request, orig_request, result,
2355 obj_request->xferred, obj_request->length);
2356 rbd_obj_request_put(obj_request);
2358 rbd_assert(orig_request);
2359 rbd_assert(orig_request->img_request);
2362 * Our only purpose here is to determine whether the object
2363 * exists, and we don't want to treat the non-existence as
2364 * an error. If something else comes back, transfer the
2365 * error to the original request and complete it now.
2368 obj_request_existence_set(orig_request, true);
2369 } else if (result == -ENOENT) {
2370 obj_request_existence_set(orig_request, false);
2371 } else if (result) {
2372 orig_request->result = result;
2377 * Resubmit the original request now that we have recorded
2378 * whether the target object exists.
2380 orig_request->result = rbd_img_obj_request_submit(orig_request);
2382 if (orig_request->result)
2383 rbd_obj_request_complete(orig_request);
2384 rbd_obj_request_put(orig_request);
2387 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2389 struct rbd_obj_request *stat_request;
2390 struct rbd_device *rbd_dev;
2391 struct ceph_osd_client *osdc;
2392 struct page **pages = NULL;
2398 * The response data for a STAT call consists of:
2405 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2406 page_count = (u32)calc_pages_for(0, size);
2407 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2409 return PTR_ERR(pages);
2412 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2417 rbd_obj_request_get(obj_request);
2418 stat_request->obj_request = obj_request;
2419 stat_request->pages = pages;
2420 stat_request->page_count = page_count;
2422 rbd_assert(obj_request->img_request);
2423 rbd_dev = obj_request->img_request->rbd_dev;
2424 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2426 if (!stat_request->osd_req)
2428 stat_request->callback = rbd_img_obj_exists_callback;
2430 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2431 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2433 rbd_osd_req_format_read(stat_request);
2435 osdc = &rbd_dev->rbd_client->client->osdc;
2436 ret = rbd_obj_request_submit(osdc, stat_request);
2439 rbd_obj_request_put(obj_request);
2444 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2446 struct rbd_img_request *img_request;
2447 struct rbd_device *rbd_dev;
2450 rbd_assert(obj_request_img_data_test(obj_request));
2452 img_request = obj_request->img_request;
2453 rbd_assert(img_request);
2454 rbd_dev = img_request->rbd_dev;
2457 * Only writes to layered images need special handling.
2458 * Reads and non-layered writes are simple object requests.
2459 * Layered writes that start beyond the end of the overlap
2460 * with the parent have no parent data, so they too are
2461 * simple object requests. Finally, if the target object is
2462 * known to already exist, its parent data has already been
2463 * copied, so a write to the object can also be handled as a
2464 * simple object request.
2466 if (!img_request_write_test(img_request) ||
2467 !img_request_layered_test(img_request) ||
2468 rbd_dev->parent_overlap <= obj_request->img_offset ||
2469 ((known = obj_request_known_test(obj_request)) &&
2470 obj_request_exists_test(obj_request))) {
2472 struct rbd_device *rbd_dev;
2473 struct ceph_osd_client *osdc;
2475 rbd_dev = obj_request->img_request->rbd_dev;
2476 osdc = &rbd_dev->rbd_client->client->osdc;
2478 return rbd_obj_request_submit(osdc, obj_request);
2482 * It's a layered write. The target object might exist but
2483 * we may not know that yet. If we know it doesn't exist,
2484 * start by reading the data for the full target object from
2485 * the parent so we can use it for a copyup to the target.
2488 return rbd_img_obj_parent_read_full(obj_request);
2490 /* We don't know whether the target exists. Go find out. */
2492 return rbd_img_obj_exists_submit(obj_request);
2495 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2497 struct rbd_obj_request *obj_request;
2498 struct rbd_obj_request *next_obj_request;
2500 dout("%s: img %p\n", __func__, img_request);
2501 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2504 ret = rbd_img_obj_request_submit(obj_request);
2512 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2514 struct rbd_obj_request *obj_request;
2515 struct rbd_device *rbd_dev;
2518 rbd_assert(img_request_child_test(img_request));
2520 obj_request = img_request->obj_request;
2521 rbd_assert(obj_request);
2522 rbd_assert(obj_request->img_request);
2524 obj_request->result = img_request->result;
2525 if (obj_request->result)
2529 * We need to zero anything beyond the parent overlap
2530 * boundary. Since rbd_img_obj_request_read_callback()
2531 * will zero anything beyond the end of a short read, an
2532 * easy way to do this is to pretend the data from the
2533 * parent came up short--ending at the overlap boundary.
2535 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2536 obj_end = obj_request->img_offset + obj_request->length;
2537 rbd_dev = obj_request->img_request->rbd_dev;
2538 if (obj_end > rbd_dev->parent_overlap) {
2541 if (obj_request->img_offset < rbd_dev->parent_overlap)
2542 xferred = rbd_dev->parent_overlap -
2543 obj_request->img_offset;
2545 obj_request->xferred = min(img_request->xferred, xferred);
2547 obj_request->xferred = img_request->xferred;
2550 rbd_img_request_put(img_request);
2551 rbd_img_obj_request_read_callback(obj_request);
2552 rbd_obj_request_complete(obj_request);
2555 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2557 struct rbd_device *rbd_dev;
2558 struct rbd_img_request *img_request;
2561 rbd_assert(obj_request_img_data_test(obj_request));
2562 rbd_assert(obj_request->img_request != NULL);
2563 rbd_assert(obj_request->result == (s32) -ENOENT);
2564 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2566 rbd_dev = obj_request->img_request->rbd_dev;
2567 rbd_assert(rbd_dev->parent != NULL);
2568 /* rbd_read_finish(obj_request, obj_request->length); */
2569 img_request = rbd_img_request_create(rbd_dev->parent,
2570 obj_request->img_offset,
2571 obj_request->length,
2577 rbd_obj_request_get(obj_request);
2578 img_request->obj_request = obj_request;
2580 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2581 obj_request->bio_list);
2585 img_request->callback = rbd_img_parent_read_callback;
2586 result = rbd_img_request_submit(img_request);
2593 rbd_img_request_put(img_request);
2594 obj_request->result = result;
2595 obj_request->xferred = 0;
2596 obj_request_done_set(obj_request);
2599 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
2601 struct rbd_obj_request *obj_request;
2602 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2605 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2606 OBJ_REQUEST_NODATA);
2611 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2612 if (!obj_request->osd_req)
2614 obj_request->callback = rbd_obj_request_put;
2616 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2618 rbd_osd_req_format_read(obj_request);
2620 ret = rbd_obj_request_submit(osdc, obj_request);
2623 rbd_obj_request_put(obj_request);
2628 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2630 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2636 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2637 rbd_dev->header_name, (unsigned long long)notify_id,
2638 (unsigned int)opcode);
2639 ret = rbd_dev_refresh(rbd_dev);
2641 rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);
2643 rbd_obj_notify_ack(rbd_dev, notify_id);
2647 * Request sync osd watch/unwatch. The value of "start" determines
2648 * whether a watch request is being initiated or torn down.
2650 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start)
2652 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2653 struct rbd_obj_request *obj_request;
2656 rbd_assert(start ^ !!rbd_dev->watch_event);
2657 rbd_assert(start ^ !!rbd_dev->watch_request);
2660 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2661 &rbd_dev->watch_event);
2664 rbd_assert(rbd_dev->watch_event != NULL);
2668 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2669 OBJ_REQUEST_NODATA);
2673 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2674 if (!obj_request->osd_req)
2678 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2680 ceph_osdc_unregister_linger_request(osdc,
2681 rbd_dev->watch_request->osd_req);
2683 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2684 rbd_dev->watch_event->cookie, 0, start);
2685 rbd_osd_req_format_write(obj_request);
2687 ret = rbd_obj_request_submit(osdc, obj_request);
2690 ret = rbd_obj_request_wait(obj_request);
2693 ret = obj_request->result;
2698 * A watch request is set to linger, so the underlying osd
2699 * request won't go away until we unregister it. We retain
2700 * a pointer to the object request during that time (in
2701 * rbd_dev->watch_request), so we'll keep a reference to
2702 * it. We'll drop that reference (below) after we've
2706 rbd_dev->watch_request = obj_request;
2711 /* We have successfully torn down the watch request */
2713 rbd_obj_request_put(rbd_dev->watch_request);
2714 rbd_dev->watch_request = NULL;
2716 /* Cancel the event if we're tearing down, or on error */
2717 ceph_osdc_cancel_event(rbd_dev->watch_event);
2718 rbd_dev->watch_event = NULL;
2720 rbd_obj_request_put(obj_request);
2726 * Synchronous osd object method call. Returns the number of bytes
2727 * returned in the outbound buffer, or a negative error code.
2729 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2730 const char *object_name,
2731 const char *class_name,
2732 const char *method_name,
2733 const void *outbound,
2734 size_t outbound_size,
2736 size_t inbound_size)
2738 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2739 struct rbd_obj_request *obj_request;
2740 struct page **pages;
2745 * Method calls are ultimately read operations. The result
2746 * should placed into the inbound buffer provided. They
2747 * also supply outbound data--parameters for the object
2748 * method. Currently if this is present it will be a
2751 page_count = (u32)calc_pages_for(0, inbound_size);
2752 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2754 return PTR_ERR(pages);
2757 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2762 obj_request->pages = pages;
2763 obj_request->page_count = page_count;
2765 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2766 if (!obj_request->osd_req)
2769 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2770 class_name, method_name);
2771 if (outbound_size) {
2772 struct ceph_pagelist *pagelist;
2774 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2778 ceph_pagelist_init(pagelist);
2779 ceph_pagelist_append(pagelist, outbound, outbound_size);
2780 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2783 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2784 obj_request->pages, inbound_size,
2786 rbd_osd_req_format_read(obj_request);
2788 ret = rbd_obj_request_submit(osdc, obj_request);
2791 ret = rbd_obj_request_wait(obj_request);
2795 ret = obj_request->result;
2799 rbd_assert(obj_request->xferred < (u64)INT_MAX);
2800 ret = (int)obj_request->xferred;
2801 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
2804 rbd_obj_request_put(obj_request);
2806 ceph_release_page_vector(pages, page_count);
2811 static void rbd_request_fn(struct request_queue *q)
2812 __releases(q->queue_lock) __acquires(q->queue_lock)
2814 struct rbd_device *rbd_dev = q->queuedata;
2815 bool read_only = rbd_dev->mapping.read_only;
2819 while ((rq = blk_fetch_request(q))) {
2820 bool write_request = rq_data_dir(rq) == WRITE;
2821 struct rbd_img_request *img_request;
2825 /* Ignore any non-FS requests that filter through. */
2827 if (rq->cmd_type != REQ_TYPE_FS) {
2828 dout("%s: non-fs request type %d\n", __func__,
2829 (int) rq->cmd_type);
2830 __blk_end_request_all(rq, 0);
2834 /* Ignore/skip any zero-length requests */
2836 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
2837 length = (u64) blk_rq_bytes(rq);
2840 dout("%s: zero-length request\n", __func__);
2841 __blk_end_request_all(rq, 0);
2845 spin_unlock_irq(q->queue_lock);
2847 /* Disallow writes to a read-only device */
2849 if (write_request) {
2853 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
2857 * Quit early if the mapped snapshot no longer
2858 * exists. It's still possible the snapshot will
2859 * have disappeared by the time our request arrives
2860 * at the osd, but there's no sense in sending it if
2863 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
2864 dout("request for non-existent snapshot");
2865 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
2871 if (offset && length > U64_MAX - offset + 1) {
2872 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
2874 goto end_request; /* Shouldn't happen */
2878 if (offset + length > rbd_dev->mapping.size) {
2879 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)\n",
2880 offset, length, rbd_dev->mapping.size);
2885 img_request = rbd_img_request_create(rbd_dev, offset, length,
2886 write_request, false);
2890 img_request->rq = rq;
2892 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2895 result = rbd_img_request_submit(img_request);
2897 rbd_img_request_put(img_request);
2899 spin_lock_irq(q->queue_lock);
2901 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
2902 write_request ? "write" : "read",
2903 length, offset, result);
2905 __blk_end_request_all(rq, result);
2911 * a queue callback. Makes sure that we don't create a bio that spans across
2912 * multiple osd objects. One exception would be with a single page bios,
2913 * which we handle later at bio_chain_clone_range()
2915 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2916 struct bio_vec *bvec)
2918 struct rbd_device *rbd_dev = q->queuedata;
2919 sector_t sector_offset;
2920 sector_t sectors_per_obj;
2921 sector_t obj_sector_offset;
2925 * Find how far into its rbd object the partition-relative
2926 * bio start sector is to offset relative to the enclosing
2929 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2930 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2931 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2934 * Compute the number of bytes from that offset to the end
2935 * of the object. Account for what's already used by the bio.
2937 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2938 if (ret > bmd->bi_size)
2939 ret -= bmd->bi_size;
2944 * Don't send back more than was asked for. And if the bio
2945 * was empty, let the whole thing through because: "Note
2946 * that a block device *must* allow a single page to be
2947 * added to an empty bio."
2949 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2950 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2951 ret = (int) bvec->bv_len;
2956 static void rbd_free_disk(struct rbd_device *rbd_dev)
2958 struct gendisk *disk = rbd_dev->disk;
2963 rbd_dev->disk = NULL;
2964 if (disk->flags & GENHD_FL_UP) {
2967 blk_cleanup_queue(disk->queue);
2972 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2973 const char *object_name,
2974 u64 offset, u64 length, void *buf)
2977 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2978 struct rbd_obj_request *obj_request;
2979 struct page **pages = NULL;
2984 page_count = (u32) calc_pages_for(offset, length);
2985 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2987 ret = PTR_ERR(pages);
2990 obj_request = rbd_obj_request_create(object_name, offset, length,
2995 obj_request->pages = pages;
2996 obj_request->page_count = page_count;
2998 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2999 if (!obj_request->osd_req)
3002 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
3003 offset, length, 0, 0);
3004 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
3006 obj_request->length,
3007 obj_request->offset & ~PAGE_MASK,
3009 rbd_osd_req_format_read(obj_request);
3011 ret = rbd_obj_request_submit(osdc, obj_request);
3014 ret = rbd_obj_request_wait(obj_request);
3018 ret = obj_request->result;
3022 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
3023 size = (size_t) obj_request->xferred;
3024 ceph_copy_from_page_vector(pages, buf, 0, size);
3025 rbd_assert(size <= (size_t)INT_MAX);
3029 rbd_obj_request_put(obj_request);
3031 ceph_release_page_vector(pages, page_count);
3037 * Read the complete header for the given rbd device.
3039 * Returns a pointer to a dynamically-allocated buffer containing
3040 * the complete and validated header. Caller can pass the address
3041 * of a variable that will be filled in with the version of the
3042 * header object at the time it was read.
3044 * Returns a pointer-coded errno if a failure occurs.
3046 static struct rbd_image_header_ondisk *
3047 rbd_dev_v1_header_read(struct rbd_device *rbd_dev)
3049 struct rbd_image_header_ondisk *ondisk = NULL;
3056 * The complete header will include an array of its 64-bit
3057 * snapshot ids, followed by the names of those snapshots as
3058 * a contiguous block of NUL-terminated strings. Note that
3059 * the number of snapshots could change by the time we read
3060 * it in, in which case we re-read it.
3067 size = sizeof (*ondisk);
3068 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
3070 ondisk = kmalloc(size, GFP_KERNEL);
3072 return ERR_PTR(-ENOMEM);
3074 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3078 if ((size_t)ret < size) {
3080 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
3084 if (!rbd_dev_ondisk_valid(ondisk)) {
3086 rbd_warn(rbd_dev, "invalid header");
3090 names_size = le64_to_cpu(ondisk->snap_names_len);
3091 want_count = snap_count;
3092 snap_count = le32_to_cpu(ondisk->snap_count);
3093 } while (snap_count != want_count);
3100 return ERR_PTR(ret);
3104 * reload the ondisk the header
3106 static int rbd_read_header(struct rbd_device *rbd_dev,
3107 struct rbd_image_header *header)
3109 struct rbd_image_header_ondisk *ondisk;
3112 ondisk = rbd_dev_v1_header_read(rbd_dev);
3114 return PTR_ERR(ondisk);
3115 ret = rbd_header_from_disk(header, ondisk);
3121 static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
3123 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
3126 if (rbd_dev->mapping.size != rbd_dev->header.image_size)
3127 rbd_dev->mapping.size = rbd_dev->header.image_size;
3131 * only read the first part of the ondisk header, without the snaps info
3133 static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev)
3136 struct rbd_image_header h;
3138 ret = rbd_read_header(rbd_dev, &h);
3142 down_write(&rbd_dev->header_rwsem);
3144 /* Update image size, and check for resize of mapped image */
3145 rbd_dev->header.image_size = h.image_size;
3146 rbd_update_mapping_size(rbd_dev);
3148 /* rbd_dev->header.object_prefix shouldn't change */
3149 kfree(rbd_dev->header.snap_sizes);
3150 kfree(rbd_dev->header.snap_names);
3151 /* osd requests may still refer to snapc */
3152 ceph_put_snap_context(rbd_dev->header.snapc);
3154 rbd_dev->header.image_size = h.image_size;
3155 rbd_dev->header.snapc = h.snapc;
3156 rbd_dev->header.snap_names = h.snap_names;
3157 rbd_dev->header.snap_sizes = h.snap_sizes;
3158 /* Free the extra copy of the object prefix */
3159 if (strcmp(rbd_dev->header.object_prefix, h.object_prefix))
3160 rbd_warn(rbd_dev, "object prefix changed (ignoring)");
3161 kfree(h.object_prefix);
3163 up_write(&rbd_dev->header_rwsem);
3169 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
3170 * has disappeared from the (just updated) snapshot context.
3172 static void rbd_exists_validate(struct rbd_device *rbd_dev)
3176 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
3179 snap_id = rbd_dev->spec->snap_id;
3180 if (snap_id == CEPH_NOSNAP)
3183 if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
3184 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3187 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3192 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3193 mapping_size = rbd_dev->mapping.size;
3194 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3195 if (rbd_dev->image_format == 1)
3196 ret = rbd_dev_v1_refresh(rbd_dev);
3198 ret = rbd_dev_v2_refresh(rbd_dev);
3200 /* If it's a mapped snapshot, validate its EXISTS flag */
3202 rbd_exists_validate(rbd_dev);
3203 mutex_unlock(&ctl_mutex);
3204 if (mapping_size != rbd_dev->mapping.size) {
3207 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3208 dout("setting size to %llu sectors", (unsigned long long)size);
3209 set_capacity(rbd_dev->disk, size);
3210 revalidate_disk(rbd_dev->disk);
3216 static int rbd_init_disk(struct rbd_device *rbd_dev)
3218 struct gendisk *disk;
3219 struct request_queue *q;
3222 /* create gendisk info */
3223 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3227 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3229 disk->major = rbd_dev->major;
3230 disk->first_minor = 0;
3231 disk->fops = &rbd_bd_ops;
3232 disk->private_data = rbd_dev;
3234 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3238 /* We use the default size, but let's be explicit about it. */
3239 blk_queue_physical_block_size(q, SECTOR_SIZE);
3241 /* set io sizes to object size */
3242 segment_size = rbd_obj_bytes(&rbd_dev->header);
3243 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3244 blk_queue_max_segment_size(q, segment_size);
3245 blk_queue_io_min(q, segment_size);
3246 blk_queue_io_opt(q, segment_size);
3248 blk_queue_merge_bvec(q, rbd_merge_bvec);
3251 q->queuedata = rbd_dev;
3253 rbd_dev->disk = disk;
3266 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3268 return container_of(dev, struct rbd_device, dev);
3271 static ssize_t rbd_size_show(struct device *dev,
3272 struct device_attribute *attr, char *buf)
3274 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3276 return sprintf(buf, "%llu\n",
3277 (unsigned long long)rbd_dev->mapping.size);
3281 * Note this shows the features for whatever's mapped, which is not
3282 * necessarily the base image.
3284 static ssize_t rbd_features_show(struct device *dev,
3285 struct device_attribute *attr, char *buf)
3287 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3289 return sprintf(buf, "0x%016llx\n",
3290 (unsigned long long)rbd_dev->mapping.features);
3293 static ssize_t rbd_major_show(struct device *dev,
3294 struct device_attribute *attr, char *buf)
3296 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3299 return sprintf(buf, "%d\n", rbd_dev->major);
3301 return sprintf(buf, "(none)\n");
3305 static ssize_t rbd_client_id_show(struct device *dev,
3306 struct device_attribute *attr, char *buf)
3308 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3310 return sprintf(buf, "client%lld\n",
3311 ceph_client_id(rbd_dev->rbd_client->client));
3314 static ssize_t rbd_pool_show(struct device *dev,
3315 struct device_attribute *attr, char *buf)
3317 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3319 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3322 static ssize_t rbd_pool_id_show(struct device *dev,
3323 struct device_attribute *attr, char *buf)
3325 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3327 return sprintf(buf, "%llu\n",
3328 (unsigned long long) rbd_dev->spec->pool_id);
3331 static ssize_t rbd_name_show(struct device *dev,
3332 struct device_attribute *attr, char *buf)
3334 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3336 if (rbd_dev->spec->image_name)
3337 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3339 return sprintf(buf, "(unknown)\n");
3342 static ssize_t rbd_image_id_show(struct device *dev,
3343 struct device_attribute *attr, char *buf)
3345 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3347 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3351 * Shows the name of the currently-mapped snapshot (or
3352 * RBD_SNAP_HEAD_NAME for the base image).
3354 static ssize_t rbd_snap_show(struct device *dev,
3355 struct device_attribute *attr,
3358 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3360 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3364 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3365 * for the parent image. If there is no parent, simply shows
3366 * "(no parent image)".
3368 static ssize_t rbd_parent_show(struct device *dev,
3369 struct device_attribute *attr,
3372 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3373 struct rbd_spec *spec = rbd_dev->parent_spec;
3378 return sprintf(buf, "(no parent image)\n");
3380 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3381 (unsigned long long) spec->pool_id, spec->pool_name);
3386 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3387 spec->image_name ? spec->image_name : "(unknown)");
3392 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3393 (unsigned long long) spec->snap_id, spec->snap_name);
3398 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3403 return (ssize_t) (bufp - buf);
3406 static ssize_t rbd_image_refresh(struct device *dev,
3407 struct device_attribute *attr,
3411 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3414 ret = rbd_dev_refresh(rbd_dev);
3416 rbd_warn(rbd_dev, ": manual header refresh error (%d)\n", ret);
3418 return ret < 0 ? ret : size;
3421 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3422 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3423 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3424 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3425 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3426 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3427 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3428 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3429 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3430 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3431 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3433 static struct attribute *rbd_attrs[] = {
3434 &dev_attr_size.attr,
3435 &dev_attr_features.attr,
3436 &dev_attr_major.attr,
3437 &dev_attr_client_id.attr,
3438 &dev_attr_pool.attr,
3439 &dev_attr_pool_id.attr,
3440 &dev_attr_name.attr,
3441 &dev_attr_image_id.attr,
3442 &dev_attr_current_snap.attr,
3443 &dev_attr_parent.attr,
3444 &dev_attr_refresh.attr,
3448 static struct attribute_group rbd_attr_group = {
3452 static const struct attribute_group *rbd_attr_groups[] = {
3457 static void rbd_sysfs_dev_release(struct device *dev)
3461 static struct device_type rbd_device_type = {
3463 .groups = rbd_attr_groups,
3464 .release = rbd_sysfs_dev_release,
3467 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3469 kref_get(&spec->kref);
3474 static void rbd_spec_free(struct kref *kref);
3475 static void rbd_spec_put(struct rbd_spec *spec)
3478 kref_put(&spec->kref, rbd_spec_free);
3481 static struct rbd_spec *rbd_spec_alloc(void)
3483 struct rbd_spec *spec;
3485 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3488 kref_init(&spec->kref);
3493 static void rbd_spec_free(struct kref *kref)
3495 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3497 kfree(spec->pool_name);
3498 kfree(spec->image_id);
3499 kfree(spec->image_name);
3500 kfree(spec->snap_name);
3504 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3505 struct rbd_spec *spec)
3507 struct rbd_device *rbd_dev;
3509 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3513 spin_lock_init(&rbd_dev->lock);
3515 INIT_LIST_HEAD(&rbd_dev->node);
3516 init_rwsem(&rbd_dev->header_rwsem);
3518 rbd_dev->spec = spec;
3519 rbd_dev->rbd_client = rbdc;
3521 /* Initialize the layout used for all rbd requests */
3523 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3524 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3525 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3526 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3531 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3533 rbd_put_client(rbd_dev->rbd_client);
3534 rbd_spec_put(rbd_dev->spec);
3539 * Get the size and object order for an image snapshot, or if
3540 * snap_id is CEPH_NOSNAP, gets this information for the base
3543 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3544 u8 *order, u64 *snap_size)
3546 __le64 snapid = cpu_to_le64(snap_id);
3551 } __attribute__ ((packed)) size_buf = { 0 };
3553 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3555 &snapid, sizeof (snapid),
3556 &size_buf, sizeof (size_buf));
3557 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3560 if (ret < sizeof (size_buf))
3564 *order = size_buf.order;
3565 *snap_size = le64_to_cpu(size_buf.size);
3567 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3568 (unsigned long long)snap_id, (unsigned int)*order,
3569 (unsigned long long)*snap_size);
3574 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3576 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3577 &rbd_dev->header.obj_order,
3578 &rbd_dev->header.image_size);
3581 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3587 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3591 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3592 "rbd", "get_object_prefix", NULL, 0,
3593 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
3594 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3599 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3600 p + ret, NULL, GFP_NOIO);
3603 if (IS_ERR(rbd_dev->header.object_prefix)) {
3604 ret = PTR_ERR(rbd_dev->header.object_prefix);
3605 rbd_dev->header.object_prefix = NULL;
3607 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3615 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3618 __le64 snapid = cpu_to_le64(snap_id);
3622 } __attribute__ ((packed)) features_buf = { 0 };
3626 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3627 "rbd", "get_features",
3628 &snapid, sizeof (snapid),
3629 &features_buf, sizeof (features_buf));
3630 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3633 if (ret < sizeof (features_buf))
3636 incompat = le64_to_cpu(features_buf.incompat);
3637 if (incompat & ~RBD_FEATURES_SUPPORTED)
3640 *snap_features = le64_to_cpu(features_buf.features);
3642 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3643 (unsigned long long)snap_id,
3644 (unsigned long long)*snap_features,
3645 (unsigned long long)le64_to_cpu(features_buf.incompat));
3650 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3652 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3653 &rbd_dev->header.features);
3656 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3658 struct rbd_spec *parent_spec;
3660 void *reply_buf = NULL;
3668 parent_spec = rbd_spec_alloc();
3672 size = sizeof (__le64) + /* pool_id */
3673 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3674 sizeof (__le64) + /* snap_id */
3675 sizeof (__le64); /* overlap */
3676 reply_buf = kmalloc(size, GFP_KERNEL);
3682 snapid = cpu_to_le64(CEPH_NOSNAP);
3683 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3684 "rbd", "get_parent",
3685 &snapid, sizeof (snapid),
3687 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3692 end = reply_buf + ret;
3694 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
3695 if (parent_spec->pool_id == CEPH_NOPOOL)
3696 goto out; /* No parent? No problem. */
3698 /* The ceph file layout needs to fit pool id in 32 bits */
3701 if (parent_spec->pool_id > (u64)U32_MAX) {
3702 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3703 (unsigned long long)parent_spec->pool_id, U32_MAX);
3707 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3708 if (IS_ERR(image_id)) {
3709 ret = PTR_ERR(image_id);
3712 parent_spec->image_id = image_id;
3713 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3714 ceph_decode_64_safe(&p, end, overlap, out_err);
3716 rbd_dev->parent_overlap = overlap;
3717 rbd_dev->parent_spec = parent_spec;
3718 parent_spec = NULL; /* rbd_dev now owns this */
3723 rbd_spec_put(parent_spec);
3728 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3732 __le64 stripe_count;
3733 } __attribute__ ((packed)) striping_info_buf = { 0 };
3734 size_t size = sizeof (striping_info_buf);
3741 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3742 "rbd", "get_stripe_unit_count", NULL, 0,
3743 (char *)&striping_info_buf, size);
3744 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3751 * We don't actually support the "fancy striping" feature
3752 * (STRIPINGV2) yet, but if the striping sizes are the
3753 * defaults the behavior is the same as before. So find
3754 * out, and only fail if the image has non-default values.
3757 obj_size = (u64)1 << rbd_dev->header.obj_order;
3758 p = &striping_info_buf;
3759 stripe_unit = ceph_decode_64(&p);
3760 if (stripe_unit != obj_size) {
3761 rbd_warn(rbd_dev, "unsupported stripe unit "
3762 "(got %llu want %llu)",
3763 stripe_unit, obj_size);
3766 stripe_count = ceph_decode_64(&p);
3767 if (stripe_count != 1) {
3768 rbd_warn(rbd_dev, "unsupported stripe count "
3769 "(got %llu want 1)", stripe_count);
3772 rbd_dev->header.stripe_unit = stripe_unit;
3773 rbd_dev->header.stripe_count = stripe_count;
3778 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3780 size_t image_id_size;
3785 void *reply_buf = NULL;
3787 char *image_name = NULL;
3790 rbd_assert(!rbd_dev->spec->image_name);
3792 len = strlen(rbd_dev->spec->image_id);
3793 image_id_size = sizeof (__le32) + len;
3794 image_id = kmalloc(image_id_size, GFP_KERNEL);
3799 end = image_id + image_id_size;
3800 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3802 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3803 reply_buf = kmalloc(size, GFP_KERNEL);
3807 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3808 "rbd", "dir_get_name",
3809 image_id, image_id_size,
3814 end = reply_buf + ret;
3816 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3817 if (IS_ERR(image_name))
3820 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3828 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3830 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3831 const char *snap_name;
3834 /* Skip over names until we find the one we are looking for */
3836 snap_name = rbd_dev->header.snap_names;
3837 while (which < snapc->num_snaps) {
3838 if (!strcmp(name, snap_name))
3839 return snapc->snaps[which];
3840 snap_name += strlen(snap_name) + 1;
3846 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3848 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3853 for (which = 0; !found && which < snapc->num_snaps; which++) {
3854 const char *snap_name;
3856 snap_id = snapc->snaps[which];
3857 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
3858 if (IS_ERR(snap_name))
3860 found = !strcmp(name, snap_name);
3863 return found ? snap_id : CEPH_NOSNAP;
3867 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
3868 * no snapshot by that name is found, or if an error occurs.
3870 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3872 if (rbd_dev->image_format == 1)
3873 return rbd_v1_snap_id_by_name(rbd_dev, name);
3875 return rbd_v2_snap_id_by_name(rbd_dev, name);
3879 * When an rbd image has a parent image, it is identified by the
3880 * pool, image, and snapshot ids (not names). This function fills
3881 * in the names for those ids. (It's OK if we can't figure out the
3882 * name for an image id, but the pool and snapshot ids should always
3883 * exist and have names.) All names in an rbd spec are dynamically
3886 * When an image being mapped (not a parent) is probed, we have the
3887 * pool name and pool id, image name and image id, and the snapshot
3888 * name. The only thing we're missing is the snapshot id.
3890 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
3892 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3893 struct rbd_spec *spec = rbd_dev->spec;
3894 const char *pool_name;
3895 const char *image_name;
3896 const char *snap_name;
3900 * An image being mapped will have the pool name (etc.), but
3901 * we need to look up the snapshot id.
3903 if (spec->pool_name) {
3904 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
3907 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
3908 if (snap_id == CEPH_NOSNAP)
3910 spec->snap_id = snap_id;
3912 spec->snap_id = CEPH_NOSNAP;
3918 /* Get the pool name; we have to make our own copy of this */
3920 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
3922 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
3925 pool_name = kstrdup(pool_name, GFP_KERNEL);
3929 /* Fetch the image name; tolerate failure here */
3931 image_name = rbd_dev_image_name(rbd_dev);
3933 rbd_warn(rbd_dev, "unable to get image name");
3935 /* Look up the snapshot name, and make a copy */
3937 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
3943 spec->pool_name = pool_name;
3944 spec->image_name = image_name;
3945 spec->snap_name = snap_name;
3955 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
3964 struct ceph_snap_context *snapc;
3968 * We'll need room for the seq value (maximum snapshot id),
3969 * snapshot count, and array of that many snapshot ids.
3970 * For now we have a fixed upper limit on the number we're
3971 * prepared to receive.
3973 size = sizeof (__le64) + sizeof (__le32) +
3974 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3975 reply_buf = kzalloc(size, GFP_KERNEL);
3979 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3980 "rbd", "get_snapcontext", NULL, 0,
3982 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3987 end = reply_buf + ret;
3989 ceph_decode_64_safe(&p, end, seq, out);
3990 ceph_decode_32_safe(&p, end, snap_count, out);
3993 * Make sure the reported number of snapshot ids wouldn't go
3994 * beyond the end of our buffer. But before checking that,
3995 * make sure the computed size of the snapshot context we
3996 * allocate is representable in a size_t.
3998 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
4003 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
4007 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4013 for (i = 0; i < snap_count; i++)
4014 snapc->snaps[i] = ceph_decode_64(&p);
4016 ceph_put_snap_context(rbd_dev->header.snapc);
4017 rbd_dev->header.snapc = snapc;
4019 dout(" snap context seq = %llu, snap_count = %u\n",
4020 (unsigned long long)seq, (unsigned int)snap_count);
4027 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
4038 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
4039 reply_buf = kmalloc(size, GFP_KERNEL);
4041 return ERR_PTR(-ENOMEM);
4043 snapid = cpu_to_le64(snap_id);
4044 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4045 "rbd", "get_snapshot_name",
4046 &snapid, sizeof (snapid),
4048 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4050 snap_name = ERR_PTR(ret);
4055 end = reply_buf + ret;
4056 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4057 if (IS_ERR(snap_name))
4060 dout(" snap_id 0x%016llx snap_name = %s\n",
4061 (unsigned long long)snap_id, snap_name);
4068 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev)
4072 down_write(&rbd_dev->header_rwsem);
4074 ret = rbd_dev_v2_image_size(rbd_dev);
4077 rbd_update_mapping_size(rbd_dev);
4079 ret = rbd_dev_v2_snap_context(rbd_dev);
4080 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4084 up_write(&rbd_dev->header_rwsem);
4089 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4094 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4096 dev = &rbd_dev->dev;
4097 dev->bus = &rbd_bus_type;
4098 dev->type = &rbd_device_type;
4099 dev->parent = &rbd_root_dev;
4100 dev->release = rbd_dev_device_release;
4101 dev_set_name(dev, "%d", rbd_dev->dev_id);
4102 ret = device_register(dev);
4104 mutex_unlock(&ctl_mutex);
4109 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4111 device_unregister(&rbd_dev->dev);
4114 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4117 * Get a unique rbd identifier for the given new rbd_dev, and add
4118 * the rbd_dev to the global list. The minimum rbd id is 1.
4120 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4122 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4124 spin_lock(&rbd_dev_list_lock);
4125 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4126 spin_unlock(&rbd_dev_list_lock);
4127 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4128 (unsigned long long) rbd_dev->dev_id);
4132 * Remove an rbd_dev from the global list, and record that its
4133 * identifier is no longer in use.
4135 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4137 struct list_head *tmp;
4138 int rbd_id = rbd_dev->dev_id;
4141 rbd_assert(rbd_id > 0);
4143 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4144 (unsigned long long) rbd_dev->dev_id);
4145 spin_lock(&rbd_dev_list_lock);
4146 list_del_init(&rbd_dev->node);
4149 * If the id being "put" is not the current maximum, there
4150 * is nothing special we need to do.
4152 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4153 spin_unlock(&rbd_dev_list_lock);
4158 * We need to update the current maximum id. Search the
4159 * list to find out what it is. We're more likely to find
4160 * the maximum at the end, so search the list backward.
4163 list_for_each_prev(tmp, &rbd_dev_list) {
4164 struct rbd_device *rbd_dev;
4166 rbd_dev = list_entry(tmp, struct rbd_device, node);
4167 if (rbd_dev->dev_id > max_id)
4168 max_id = rbd_dev->dev_id;
4170 spin_unlock(&rbd_dev_list_lock);
4173 * The max id could have been updated by rbd_dev_id_get(), in
4174 * which case it now accurately reflects the new maximum.
4175 * Be careful not to overwrite the maximum value in that
4178 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4179 dout(" max dev id has been reset\n");
4183 * Skips over white space at *buf, and updates *buf to point to the
4184 * first found non-space character (if any). Returns the length of
4185 * the token (string of non-white space characters) found. Note
4186 * that *buf must be terminated with '\0'.
4188 static inline size_t next_token(const char **buf)
4191 * These are the characters that produce nonzero for
4192 * isspace() in the "C" and "POSIX" locales.
4194 const char *spaces = " \f\n\r\t\v";
4196 *buf += strspn(*buf, spaces); /* Find start of token */
4198 return strcspn(*buf, spaces); /* Return token length */
4202 * Finds the next token in *buf, and if the provided token buffer is
4203 * big enough, copies the found token into it. The result, if
4204 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4205 * must be terminated with '\0' on entry.
4207 * Returns the length of the token found (not including the '\0').
4208 * Return value will be 0 if no token is found, and it will be >=
4209 * token_size if the token would not fit.
4211 * The *buf pointer will be updated to point beyond the end of the
4212 * found token. Note that this occurs even if the token buffer is
4213 * too small to hold it.
4215 static inline size_t copy_token(const char **buf,
4221 len = next_token(buf);
4222 if (len < token_size) {
4223 memcpy(token, *buf, len);
4224 *(token + len) = '\0';
4232 * Finds the next token in *buf, dynamically allocates a buffer big
4233 * enough to hold a copy of it, and copies the token into the new
4234 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4235 * that a duplicate buffer is created even for a zero-length token.
4237 * Returns a pointer to the newly-allocated duplicate, or a null
4238 * pointer if memory for the duplicate was not available. If
4239 * the lenp argument is a non-null pointer, the length of the token
4240 * (not including the '\0') is returned in *lenp.
4242 * If successful, the *buf pointer will be updated to point beyond
4243 * the end of the found token.
4245 * Note: uses GFP_KERNEL for allocation.
4247 static inline char *dup_token(const char **buf, size_t *lenp)
4252 len = next_token(buf);
4253 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4256 *(dup + len) = '\0';
4266 * Parse the options provided for an "rbd add" (i.e., rbd image
4267 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4268 * and the data written is passed here via a NUL-terminated buffer.
4269 * Returns 0 if successful or an error code otherwise.
4271 * The information extracted from these options is recorded in
4272 * the other parameters which return dynamically-allocated
4275 * The address of a pointer that will refer to a ceph options
4276 * structure. Caller must release the returned pointer using
4277 * ceph_destroy_options() when it is no longer needed.
4279 * Address of an rbd options pointer. Fully initialized by
4280 * this function; caller must release with kfree().
4282 * Address of an rbd image specification pointer. Fully
4283 * initialized by this function based on parsed options.
4284 * Caller must release with rbd_spec_put().
4286 * The options passed take this form:
4287 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4290 * A comma-separated list of one or more monitor addresses.
4291 * A monitor address is an ip address, optionally followed
4292 * by a port number (separated by a colon).
4293 * I.e.: ip1[:port1][,ip2[:port2]...]
4295 * A comma-separated list of ceph and/or rbd options.
4297 * The name of the rados pool containing the rbd image.
4299 * The name of the image in that pool to map.
4301 * An optional snapshot id. If provided, the mapping will
4302 * present data from the image at the time that snapshot was
4303 * created. The image head is used if no snapshot id is
4304 * provided. Snapshot mappings are always read-only.
4306 static int rbd_add_parse_args(const char *buf,
4307 struct ceph_options **ceph_opts,
4308 struct rbd_options **opts,
4309 struct rbd_spec **rbd_spec)
4313 const char *mon_addrs;
4315 size_t mon_addrs_size;
4316 struct rbd_spec *spec = NULL;
4317 struct rbd_options *rbd_opts = NULL;
4318 struct ceph_options *copts;
4321 /* The first four tokens are required */
4323 len = next_token(&buf);
4325 rbd_warn(NULL, "no monitor address(es) provided");
4329 mon_addrs_size = len + 1;
4333 options = dup_token(&buf, NULL);
4337 rbd_warn(NULL, "no options provided");
4341 spec = rbd_spec_alloc();
4345 spec->pool_name = dup_token(&buf, NULL);
4346 if (!spec->pool_name)
4348 if (!*spec->pool_name) {
4349 rbd_warn(NULL, "no pool name provided");
4353 spec->image_name = dup_token(&buf, NULL);
4354 if (!spec->image_name)
4356 if (!*spec->image_name) {
4357 rbd_warn(NULL, "no image name provided");
4362 * Snapshot name is optional; default is to use "-"
4363 * (indicating the head/no snapshot).
4365 len = next_token(&buf);
4367 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4368 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4369 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4370 ret = -ENAMETOOLONG;
4373 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4376 *(snap_name + len) = '\0';
4377 spec->snap_name = snap_name;
4379 /* Initialize all rbd options to the defaults */
4381 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4385 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4387 copts = ceph_parse_options(options, mon_addrs,
4388 mon_addrs + mon_addrs_size - 1,
4389 parse_rbd_opts_token, rbd_opts);
4390 if (IS_ERR(copts)) {
4391 ret = PTR_ERR(copts);
4412 * An rbd format 2 image has a unique identifier, distinct from the
4413 * name given to it by the user. Internally, that identifier is
4414 * what's used to specify the names of objects related to the image.
4416 * A special "rbd id" object is used to map an rbd image name to its
4417 * id. If that object doesn't exist, then there is no v2 rbd image
4418 * with the supplied name.
4420 * This function will record the given rbd_dev's image_id field if
4421 * it can be determined, and in that case will return 0. If any
4422 * errors occur a negative errno will be returned and the rbd_dev's
4423 * image_id field will be unchanged (and should be NULL).
4425 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4434 * When probing a parent image, the image id is already
4435 * known (and the image name likely is not). There's no
4436 * need to fetch the image id again in this case. We
4437 * do still need to set the image format though.
4439 if (rbd_dev->spec->image_id) {
4440 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4446 * First, see if the format 2 image id file exists, and if
4447 * so, get the image's persistent id from it.
4449 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4450 object_name = kmalloc(size, GFP_NOIO);
4453 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4454 dout("rbd id object name is %s\n", object_name);
4456 /* Response will be an encoded string, which includes a length */
4458 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4459 response = kzalloc(size, GFP_NOIO);
4465 /* If it doesn't exist we'll assume it's a format 1 image */
4467 ret = rbd_obj_method_sync(rbd_dev, object_name,
4468 "rbd", "get_id", NULL, 0,
4469 response, RBD_IMAGE_ID_LEN_MAX);
4470 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4471 if (ret == -ENOENT) {
4472 image_id = kstrdup("", GFP_KERNEL);
4473 ret = image_id ? 0 : -ENOMEM;
4475 rbd_dev->image_format = 1;
4476 } else if (ret > sizeof (__le32)) {
4479 image_id = ceph_extract_encoded_string(&p, p + ret,
4481 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4483 rbd_dev->image_format = 2;
4489 rbd_dev->spec->image_id = image_id;
4490 dout("image_id is %s\n", image_id);
4499 /* Undo whatever state changes are made by v1 or v2 image probe */
4501 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
4503 struct rbd_image_header *header;
4505 rbd_dev_remove_parent(rbd_dev);
4506 rbd_spec_put(rbd_dev->parent_spec);
4507 rbd_dev->parent_spec = NULL;
4508 rbd_dev->parent_overlap = 0;
4510 /* Free dynamic fields from the header, then zero it out */
4512 header = &rbd_dev->header;
4513 ceph_put_snap_context(header->snapc);
4514 kfree(header->snap_sizes);
4515 kfree(header->snap_names);
4516 kfree(header->object_prefix);
4517 memset(header, 0, sizeof (*header));
4520 static int rbd_dev_v1_probe(struct rbd_device *rbd_dev)
4524 /* Populate rbd image metadata */
4526 ret = rbd_read_header(rbd_dev, &rbd_dev->header);
4530 /* Version 1 images have no parent (no layering) */
4532 rbd_dev->parent_spec = NULL;
4533 rbd_dev->parent_overlap = 0;
4535 dout("discovered version 1 image, header name is %s\n",
4536 rbd_dev->header_name);
4541 kfree(rbd_dev->header_name);
4542 rbd_dev->header_name = NULL;
4543 kfree(rbd_dev->spec->image_id);
4544 rbd_dev->spec->image_id = NULL;
4549 static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
4553 ret = rbd_dev_v2_image_size(rbd_dev);
4557 /* Get the object prefix (a.k.a. block_name) for the image */
4559 ret = rbd_dev_v2_object_prefix(rbd_dev);
4563 /* Get the and check features for the image */
4565 ret = rbd_dev_v2_features(rbd_dev);
4569 /* If the image supports layering, get the parent info */
4571 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
4572 ret = rbd_dev_v2_parent_info(rbd_dev);
4577 * Don't print a warning for parent images. We can
4578 * tell this point because we won't know its pool
4579 * name yet (just its pool id).
4581 if (rbd_dev->spec->pool_name)
4582 rbd_warn(rbd_dev, "WARNING: kernel layering "
4583 "is EXPERIMENTAL!");
4586 /* If the image supports fancy striping, get its parameters */
4588 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4589 ret = rbd_dev_v2_striping_info(rbd_dev);
4594 /* crypto and compression type aren't (yet) supported for v2 images */
4596 rbd_dev->header.crypt_type = 0;
4597 rbd_dev->header.comp_type = 0;
4599 /* Get the snapshot context, plus the header version */
4601 ret = rbd_dev_v2_snap_context(rbd_dev);
4605 dout("discovered version 2 image, header name is %s\n",
4606 rbd_dev->header_name);
4610 rbd_dev->parent_overlap = 0;
4611 rbd_spec_put(rbd_dev->parent_spec);
4612 rbd_dev->parent_spec = NULL;
4613 kfree(rbd_dev->header_name);
4614 rbd_dev->header_name = NULL;
4615 kfree(rbd_dev->header.object_prefix);
4616 rbd_dev->header.object_prefix = NULL;
4621 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4623 struct rbd_device *parent = NULL;
4624 struct rbd_spec *parent_spec;
4625 struct rbd_client *rbdc;
4628 if (!rbd_dev->parent_spec)
4631 * We need to pass a reference to the client and the parent
4632 * spec when creating the parent rbd_dev. Images related by
4633 * parent/child relationships always share both.
4635 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4636 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4639 parent = rbd_dev_create(rbdc, parent_spec);
4643 ret = rbd_dev_image_probe(parent);
4646 rbd_dev->parent = parent;
4651 rbd_spec_put(rbd_dev->parent_spec);
4652 kfree(rbd_dev->header_name);
4653 rbd_dev_destroy(parent);
4655 rbd_put_client(rbdc);
4656 rbd_spec_put(parent_spec);
4662 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
4666 ret = rbd_dev_mapping_set(rbd_dev);
4670 /* generate unique id: find highest unique id, add one */
4671 rbd_dev_id_get(rbd_dev);
4673 /* Fill in the device name, now that we have its id. */
4674 BUILD_BUG_ON(DEV_NAME_LEN
4675 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4676 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4678 /* Get our block major device number. */
4680 ret = register_blkdev(0, rbd_dev->name);
4683 rbd_dev->major = ret;
4685 /* Set up the blkdev mapping. */
4687 ret = rbd_init_disk(rbd_dev);
4689 goto err_out_blkdev;
4691 ret = rbd_bus_add_dev(rbd_dev);
4695 /* Everything's ready. Announce the disk to the world. */
4697 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4698 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4699 add_disk(rbd_dev->disk);
4701 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4702 (unsigned long long) rbd_dev->mapping.size);
4707 rbd_free_disk(rbd_dev);
4709 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4711 rbd_dev_id_put(rbd_dev);
4712 rbd_dev_mapping_clear(rbd_dev);
4717 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
4719 struct rbd_spec *spec = rbd_dev->spec;
4722 /* Record the header object name for this rbd image. */
4724 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4726 if (rbd_dev->image_format == 1)
4727 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
4729 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
4731 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4732 if (!rbd_dev->header_name)
4735 if (rbd_dev->image_format == 1)
4736 sprintf(rbd_dev->header_name, "%s%s",
4737 spec->image_name, RBD_SUFFIX);
4739 sprintf(rbd_dev->header_name, "%s%s",
4740 RBD_HEADER_PREFIX, spec->image_id);
4744 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
4748 rbd_dev_unprobe(rbd_dev);
4749 ret = rbd_dev_header_watch_sync(rbd_dev, 0);
4751 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
4752 kfree(rbd_dev->header_name);
4753 rbd_dev->header_name = NULL;
4754 rbd_dev->image_format = 0;
4755 kfree(rbd_dev->spec->image_id);
4756 rbd_dev->spec->image_id = NULL;
4758 rbd_dev_destroy(rbd_dev);
4762 * Probe for the existence of the header object for the given rbd
4763 * device. For format 2 images this includes determining the image
4766 static int rbd_dev_image_probe(struct rbd_device *rbd_dev)
4772 * Get the id from the image id object. If it's not a
4773 * format 2 image, we'll get ENOENT back, and we'll assume
4774 * it's a format 1 image.
4776 ret = rbd_dev_image_id(rbd_dev);
4779 rbd_assert(rbd_dev->spec->image_id);
4780 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4782 ret = rbd_dev_header_name(rbd_dev);
4784 goto err_out_format;
4786 ret = rbd_dev_header_watch_sync(rbd_dev, 1);
4788 goto out_header_name;
4790 if (rbd_dev->image_format == 1)
4791 ret = rbd_dev_v1_probe(rbd_dev);
4793 ret = rbd_dev_v2_probe(rbd_dev);
4797 ret = rbd_dev_spec_update(rbd_dev);
4801 ret = rbd_dev_probe_parent(rbd_dev);
4806 rbd_dev_unprobe(rbd_dev);
4808 tmp = rbd_dev_header_watch_sync(rbd_dev, 0);
4810 rbd_warn(rbd_dev, "unable to tear down watch request\n");
4812 kfree(rbd_dev->header_name);
4813 rbd_dev->header_name = NULL;
4815 rbd_dev->image_format = 0;
4816 kfree(rbd_dev->spec->image_id);
4817 rbd_dev->spec->image_id = NULL;
4819 dout("probe failed, returning %d\n", ret);
4824 static ssize_t rbd_add(struct bus_type *bus,
4828 struct rbd_device *rbd_dev = NULL;
4829 struct ceph_options *ceph_opts = NULL;
4830 struct rbd_options *rbd_opts = NULL;
4831 struct rbd_spec *spec = NULL;
4832 struct rbd_client *rbdc;
4833 struct ceph_osd_client *osdc;
4836 if (!try_module_get(THIS_MODULE))
4839 /* parse add command */
4840 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4842 goto err_out_module;
4844 rbdc = rbd_get_client(ceph_opts);
4849 ceph_opts = NULL; /* rbd_dev client now owns this */
4852 osdc = &rbdc->client->osdc;
4853 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4855 goto err_out_client;
4856 spec->pool_id = (u64)rc;
4858 /* The ceph file layout needs to fit pool id in 32 bits */
4860 if (spec->pool_id > (u64)U32_MAX) {
4861 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4862 (unsigned long long)spec->pool_id, U32_MAX);
4864 goto err_out_client;
4867 rbd_dev = rbd_dev_create(rbdc, spec);
4869 goto err_out_client;
4870 rbdc = NULL; /* rbd_dev now owns this */
4871 spec = NULL; /* rbd_dev now owns this */
4873 rbd_dev->mapping.read_only = rbd_opts->read_only;
4875 rbd_opts = NULL; /* done with this */
4877 rc = rbd_dev_image_probe(rbd_dev);
4879 goto err_out_rbd_dev;
4881 rc = rbd_dev_device_setup(rbd_dev);
4885 rbd_dev_image_release(rbd_dev);
4887 rbd_dev_destroy(rbd_dev);
4889 rbd_put_client(rbdc);
4892 ceph_destroy_options(ceph_opts);
4896 module_put(THIS_MODULE);
4898 dout("Error adding device %s\n", buf);
4903 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4905 struct list_head *tmp;
4906 struct rbd_device *rbd_dev;
4908 spin_lock(&rbd_dev_list_lock);
4909 list_for_each(tmp, &rbd_dev_list) {
4910 rbd_dev = list_entry(tmp, struct rbd_device, node);
4911 if (rbd_dev->dev_id == dev_id) {
4912 spin_unlock(&rbd_dev_list_lock);
4916 spin_unlock(&rbd_dev_list_lock);
4920 static void rbd_dev_device_release(struct device *dev)
4922 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4924 rbd_free_disk(rbd_dev);
4925 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4926 rbd_dev_clear_mapping(rbd_dev);
4927 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4929 rbd_dev_id_put(rbd_dev);
4930 rbd_dev_mapping_clear(rbd_dev);
4933 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
4935 while (rbd_dev->parent) {
4936 struct rbd_device *first = rbd_dev;
4937 struct rbd_device *second = first->parent;
4938 struct rbd_device *third;
4941 * Follow to the parent with no grandparent and
4944 while (second && (third = second->parent)) {
4949 rbd_dev_image_release(second);
4950 first->parent = NULL;
4951 first->parent_overlap = 0;
4953 rbd_assert(first->parent_spec);
4954 rbd_spec_put(first->parent_spec);
4955 first->parent_spec = NULL;
4959 static ssize_t rbd_remove(struct bus_type *bus,
4963 struct rbd_device *rbd_dev = NULL;
4968 ret = strict_strtoul(buf, 10, &ul);
4972 /* convert to int; abort if we lost anything in the conversion */
4973 target_id = (int) ul;
4974 if (target_id != ul)
4977 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4979 rbd_dev = __rbd_get_dev(target_id);
4985 spin_lock_irq(&rbd_dev->lock);
4986 if (rbd_dev->open_count)
4989 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
4990 spin_unlock_irq(&rbd_dev->lock);
4994 rbd_bus_del_dev(rbd_dev);
4995 rbd_dev_image_release(rbd_dev);
4996 module_put(THIS_MODULE);
4998 mutex_unlock(&ctl_mutex);
5004 * create control files in sysfs
5007 static int rbd_sysfs_init(void)
5011 ret = device_register(&rbd_root_dev);
5015 ret = bus_register(&rbd_bus_type);
5017 device_unregister(&rbd_root_dev);
5022 static void rbd_sysfs_cleanup(void)
5024 bus_unregister(&rbd_bus_type);
5025 device_unregister(&rbd_root_dev);
5028 static int rbd_slab_init(void)
5030 rbd_assert(!rbd_img_request_cache);
5031 rbd_img_request_cache = kmem_cache_create("rbd_img_request",
5032 sizeof (struct rbd_img_request),
5033 __alignof__(struct rbd_img_request),
5035 if (!rbd_img_request_cache)
5038 rbd_assert(!rbd_obj_request_cache);
5039 rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
5040 sizeof (struct rbd_obj_request),
5041 __alignof__(struct rbd_obj_request),
5043 if (!rbd_obj_request_cache)
5046 rbd_assert(!rbd_segment_name_cache);
5047 rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
5048 MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
5049 if (rbd_segment_name_cache)
5052 if (rbd_obj_request_cache) {
5053 kmem_cache_destroy(rbd_obj_request_cache);
5054 rbd_obj_request_cache = NULL;
5057 kmem_cache_destroy(rbd_img_request_cache);
5058 rbd_img_request_cache = NULL;
5063 static void rbd_slab_exit(void)
5065 rbd_assert(rbd_segment_name_cache);
5066 kmem_cache_destroy(rbd_segment_name_cache);
5067 rbd_segment_name_cache = NULL;
5069 rbd_assert(rbd_obj_request_cache);
5070 kmem_cache_destroy(rbd_obj_request_cache);
5071 rbd_obj_request_cache = NULL;
5073 rbd_assert(rbd_img_request_cache);
5074 kmem_cache_destroy(rbd_img_request_cache);
5075 rbd_img_request_cache = NULL;
5078 static int __init rbd_init(void)
5082 if (!libceph_compatible(NULL)) {
5083 rbd_warn(NULL, "libceph incompatibility (quitting)");
5087 rc = rbd_slab_init();
5090 rc = rbd_sysfs_init();
5094 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5099 static void __exit rbd_exit(void)
5101 rbd_sysfs_cleanup();
5105 module_init(rbd_init);
5106 module_exit(rbd_exit);
5108 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5109 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5110 MODULE_DESCRIPTION("rados block device");
5112 /* following authorship retained from original osdblk.c */
5113 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5115 MODULE_LICENSE("GPL");