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 six fields never change for a given rbd image */
110 u64 features; /* Might be changeable someday? */
112 /* The remaining fields need to be updated occasionally */
114 struct ceph_snap_context *snapc;
115 char *snap_names; /* format 1 only */
116 u64 *snap_sizes; /* format 1 only */
120 * An rbd image specification.
122 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
123 * identify an image. Each rbd_dev structure includes a pointer to
124 * an rbd_spec structure that encapsulates this identity.
126 * Each of the id's in an rbd_spec has an associated name. For a
127 * user-mapped image, the names are supplied and the id's associated
128 * with them are looked up. For a layered image, a parent image is
129 * defined by the tuple, and the names are looked up.
131 * An rbd_dev structure contains a parent_spec pointer which is
132 * non-null if the image it represents is a child in a layered
133 * image. This pointer will refer to the rbd_spec structure used
134 * by the parent rbd_dev for its own identity (i.e., the structure
135 * is shared between the parent and child).
137 * Since these structures are populated once, during the discovery
138 * phase of image construction, they are effectively immutable so
139 * we make no effort to synchronize access to them.
141 * Note that code herein does not assume the image name is known (it
142 * could be a null pointer).
146 const char *pool_name;
148 const char *image_id;
149 const char *image_name;
152 const char *snap_name;
158 * an instance of the client. multiple devices may share an rbd client.
161 struct ceph_client *client;
163 struct list_head node;
166 struct rbd_img_request;
167 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
169 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
171 struct rbd_obj_request;
172 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
174 enum obj_request_type {
175 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
179 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
180 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
181 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
182 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
185 struct rbd_obj_request {
186 const char *object_name;
187 u64 offset; /* object start byte */
188 u64 length; /* bytes from offset */
192 * An object request associated with an image will have its
193 * img_data flag set; a standalone object request will not.
195 * A standalone object request will have which == BAD_WHICH
196 * and a null obj_request pointer.
198 * An object request initiated in support of a layered image
199 * object (to check for its existence before a write) will
200 * have which == BAD_WHICH and a non-null obj_request pointer.
202 * Finally, an object request for rbd image data will have
203 * which != BAD_WHICH, and will have a non-null img_request
204 * pointer. The value of which will be in the range
205 * 0..(img_request->obj_request_count-1).
208 struct rbd_obj_request *obj_request; /* STAT op */
210 struct rbd_img_request *img_request;
212 /* links for img_request->obj_requests list */
213 struct list_head links;
216 u32 which; /* posn image request list */
218 enum obj_request_type type;
220 struct bio *bio_list;
226 struct page **copyup_pages;
228 struct ceph_osd_request *osd_req;
230 u64 xferred; /* bytes transferred */
233 rbd_obj_callback_t callback;
234 struct completion completion;
240 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
241 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
242 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
245 struct rbd_img_request {
246 struct rbd_device *rbd_dev;
247 u64 offset; /* starting image byte offset */
248 u64 length; /* byte count from offset */
251 u64 snap_id; /* for reads */
252 struct ceph_snap_context *snapc; /* for writes */
255 struct request *rq; /* block request */
256 struct rbd_obj_request *obj_request; /* obj req initiator */
258 struct page **copyup_pages;
259 spinlock_t completion_lock;/* protects next_completion */
261 rbd_img_callback_t callback;
262 u64 xferred;/* aggregate bytes transferred */
263 int result; /* first nonzero obj_request result */
265 u32 obj_request_count;
266 struct list_head obj_requests; /* rbd_obj_request structs */
271 #define for_each_obj_request(ireq, oreq) \
272 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
273 #define for_each_obj_request_from(ireq, oreq) \
274 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
275 #define for_each_obj_request_safe(ireq, oreq, n) \
276 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
288 int dev_id; /* blkdev unique id */
290 int major; /* blkdev assigned major */
291 struct gendisk *disk; /* blkdev's gendisk and rq */
293 u32 image_format; /* Either 1 or 2 */
294 struct rbd_client *rbd_client;
296 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
298 spinlock_t lock; /* queue, flags, open_count */
300 struct rbd_image_header header;
301 unsigned long flags; /* possibly lock protected */
302 struct rbd_spec *spec;
306 struct ceph_file_layout layout;
308 struct ceph_osd_event *watch_event;
309 struct rbd_obj_request *watch_request;
311 struct rbd_spec *parent_spec;
313 struct rbd_device *parent;
315 /* protects updating the header */
316 struct rw_semaphore header_rwsem;
318 struct rbd_mapping mapping;
320 struct list_head node;
324 unsigned long open_count; /* protected by lock */
328 * Flag bits for rbd_dev->flags. If atomicity is required,
329 * rbd_dev->lock is used to protect access.
331 * Currently, only the "removing" flag (which is coupled with the
332 * "open_count" field) requires atomic access.
335 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
336 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
339 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
341 static LIST_HEAD(rbd_dev_list); /* devices */
342 static DEFINE_SPINLOCK(rbd_dev_list_lock);
344 static LIST_HEAD(rbd_client_list); /* clients */
345 static DEFINE_SPINLOCK(rbd_client_list_lock);
347 /* Slab caches for frequently-allocated structures */
349 static struct kmem_cache *rbd_img_request_cache;
350 static struct kmem_cache *rbd_obj_request_cache;
351 static struct kmem_cache *rbd_segment_name_cache;
353 static int rbd_img_request_submit(struct rbd_img_request *img_request);
355 static void rbd_dev_device_release(struct device *dev);
357 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
359 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
361 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping);
363 static struct bus_attribute rbd_bus_attrs[] = {
364 __ATTR(add, S_IWUSR, NULL, rbd_add),
365 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
369 static struct bus_type rbd_bus_type = {
371 .bus_attrs = rbd_bus_attrs,
374 static void rbd_root_dev_release(struct device *dev)
378 static struct device rbd_root_dev = {
380 .release = rbd_root_dev_release,
383 static __printf(2, 3)
384 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
386 struct va_format vaf;
394 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
395 else if (rbd_dev->disk)
396 printk(KERN_WARNING "%s: %s: %pV\n",
397 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
398 else if (rbd_dev->spec && rbd_dev->spec->image_name)
399 printk(KERN_WARNING "%s: image %s: %pV\n",
400 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
401 else if (rbd_dev->spec && rbd_dev->spec->image_id)
402 printk(KERN_WARNING "%s: id %s: %pV\n",
403 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
405 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
406 RBD_DRV_NAME, rbd_dev, &vaf);
411 #define rbd_assert(expr) \
412 if (unlikely(!(expr))) { \
413 printk(KERN_ERR "\nAssertion failure in %s() " \
415 "\trbd_assert(%s);\n\n", \
416 __func__, __LINE__, #expr); \
419 #else /* !RBD_DEBUG */
420 # define rbd_assert(expr) ((void) 0)
421 #endif /* !RBD_DEBUG */
423 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
424 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
425 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
427 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
428 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
429 static int rbd_dev_v2_header_info(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 * Fill an rbd image header with information from the given format 1
734 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
735 struct rbd_image_header_ondisk *ondisk)
737 struct rbd_image_header *header = &rbd_dev->header;
738 bool first_time = header->object_prefix == NULL;
739 struct ceph_snap_context *snapc;
740 char *object_prefix = NULL;
741 char *snap_names = NULL;
742 u64 *snap_sizes = NULL;
748 /* Allocate this now to avoid having to handle failure below */
753 len = strnlen(ondisk->object_prefix,
754 sizeof (ondisk->object_prefix));
755 object_prefix = kmalloc(len + 1, GFP_KERNEL);
758 memcpy(object_prefix, ondisk->object_prefix, len);
759 object_prefix[len] = '\0';
762 /* Allocate the snapshot context and fill it in */
764 snap_count = le32_to_cpu(ondisk->snap_count);
765 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
768 snapc->seq = le64_to_cpu(ondisk->snap_seq);
770 struct rbd_image_snap_ondisk *snaps;
771 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
773 /* We'll keep a copy of the snapshot names... */
775 if (snap_names_len > (u64)SIZE_MAX)
777 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
781 /* ...as well as the array of their sizes. */
783 size = snap_count * sizeof (*header->snap_sizes);
784 snap_sizes = kmalloc(size, GFP_KERNEL);
789 * Copy the names, and fill in each snapshot's id
792 * Note that rbd_dev_v1_header_info() guarantees the
793 * ondisk buffer we're working with has
794 * snap_names_len bytes beyond the end of the
795 * snapshot id array, this memcpy() is safe.
797 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
798 snaps = ondisk->snaps;
799 for (i = 0; i < snap_count; i++) {
800 snapc->snaps[i] = le64_to_cpu(snaps[i].id);
801 snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
805 /* We won't fail any more, fill in the header */
807 down_write(&rbd_dev->header_rwsem);
809 header->object_prefix = object_prefix;
810 header->obj_order = ondisk->options.order;
811 header->crypt_type = ondisk->options.crypt_type;
812 header->comp_type = ondisk->options.comp_type;
813 /* The rest aren't used for format 1 images */
814 header->stripe_unit = 0;
815 header->stripe_count = 0;
816 header->features = 0;
818 ceph_put_snap_context(header->snapc);
819 kfree(header->snap_names);
820 kfree(header->snap_sizes);
823 /* The remaining fields always get updated (when we refresh) */
825 header->image_size = le64_to_cpu(ondisk->image_size);
826 header->snapc = snapc;
827 header->snap_names = snap_names;
828 header->snap_sizes = snap_sizes;
830 /* Make sure mapping size is consistent with header info */
832 if (rbd_dev->spec->snap_id == CEPH_NOSNAP || first_time)
833 if (rbd_dev->mapping.size != header->image_size)
834 rbd_dev->mapping.size = header->image_size;
836 up_write(&rbd_dev->header_rwsem);
844 ceph_put_snap_context(snapc);
845 kfree(object_prefix);
850 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
852 const char *snap_name;
854 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
856 /* Skip over names until we find the one we are looking for */
858 snap_name = rbd_dev->header.snap_names;
860 snap_name += strlen(snap_name) + 1;
862 return kstrdup(snap_name, GFP_KERNEL);
866 * Snapshot id comparison function for use with qsort()/bsearch().
867 * Note that result is for snapshots in *descending* order.
869 static int snapid_compare_reverse(const void *s1, const void *s2)
871 u64 snap_id1 = *(u64 *)s1;
872 u64 snap_id2 = *(u64 *)s2;
874 if (snap_id1 < snap_id2)
876 return snap_id1 == snap_id2 ? 0 : -1;
880 * Search a snapshot context to see if the given snapshot id is
883 * Returns the position of the snapshot id in the array if it's found,
884 * or BAD_SNAP_INDEX otherwise.
886 * Note: The snapshot array is in kept sorted (by the osd) in
887 * reverse order, highest snapshot id first.
889 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
891 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
894 found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
895 sizeof (snap_id), snapid_compare_reverse);
897 return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
900 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
905 which = rbd_dev_snap_index(rbd_dev, snap_id);
906 if (which == BAD_SNAP_INDEX)
909 return _rbd_dev_v1_snap_name(rbd_dev, which);
912 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
914 if (snap_id == CEPH_NOSNAP)
915 return RBD_SNAP_HEAD_NAME;
917 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
918 if (rbd_dev->image_format == 1)
919 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
921 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
924 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
927 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
928 if (snap_id == CEPH_NOSNAP) {
929 *snap_size = rbd_dev->header.image_size;
930 } else if (rbd_dev->image_format == 1) {
933 which = rbd_dev_snap_index(rbd_dev, snap_id);
934 if (which == BAD_SNAP_INDEX)
937 *snap_size = rbd_dev->header.snap_sizes[which];
942 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
951 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
954 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
955 if (snap_id == CEPH_NOSNAP) {
956 *snap_features = rbd_dev->header.features;
957 } else if (rbd_dev->image_format == 1) {
958 *snap_features = 0; /* No features for format 1 */
963 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
967 *snap_features = features;
972 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
974 u64 snap_id = rbd_dev->spec->snap_id;
979 ret = rbd_snap_size(rbd_dev, snap_id, &size);
982 ret = rbd_snap_features(rbd_dev, snap_id, &features);
986 rbd_dev->mapping.size = size;
987 rbd_dev->mapping.features = features;
992 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
994 rbd_dev->mapping.size = 0;
995 rbd_dev->mapping.features = 0;
998 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1004 name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
1007 segment = offset >> rbd_dev->header.obj_order;
1008 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
1009 rbd_dev->header.object_prefix, segment);
1010 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
1011 pr_err("error formatting segment name for #%llu (%d)\n",
1020 static void rbd_segment_name_free(const char *name)
1022 /* The explicit cast here is needed to drop the const qualifier */
1024 kmem_cache_free(rbd_segment_name_cache, (void *)name);
1027 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1029 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1031 return offset & (segment_size - 1);
1034 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1035 u64 offset, u64 length)
1037 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1039 offset &= segment_size - 1;
1041 rbd_assert(length <= U64_MAX - offset);
1042 if (offset + length > segment_size)
1043 length = segment_size - offset;
1049 * returns the size of an object in the image
1051 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1053 return 1 << header->obj_order;
1060 static void bio_chain_put(struct bio *chain)
1066 chain = chain->bi_next;
1072 * zeros a bio chain, starting at specific offset
1074 static void zero_bio_chain(struct bio *chain, int start_ofs)
1077 unsigned long flags;
1083 bio_for_each_segment(bv, chain, i) {
1084 if (pos + bv->bv_len > start_ofs) {
1085 int remainder = max(start_ofs - pos, 0);
1086 buf = bvec_kmap_irq(bv, &flags);
1087 memset(buf + remainder, 0,
1088 bv->bv_len - remainder);
1089 bvec_kunmap_irq(buf, &flags);
1094 chain = chain->bi_next;
1099 * similar to zero_bio_chain(), zeros data defined by a page array,
1100 * starting at the given byte offset from the start of the array and
1101 * continuing up to the given end offset. The pages array is
1102 * assumed to be big enough to hold all bytes up to the end.
1104 static void zero_pages(struct page **pages, u64 offset, u64 end)
1106 struct page **page = &pages[offset >> PAGE_SHIFT];
1108 rbd_assert(end > offset);
1109 rbd_assert(end - offset <= (u64)SIZE_MAX);
1110 while (offset < end) {
1113 unsigned long flags;
1116 page_offset = (size_t)(offset & ~PAGE_MASK);
1117 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1118 local_irq_save(flags);
1119 kaddr = kmap_atomic(*page);
1120 memset(kaddr + page_offset, 0, length);
1121 kunmap_atomic(kaddr);
1122 local_irq_restore(flags);
1130 * Clone a portion of a bio, starting at the given byte offset
1131 * and continuing for the number of bytes indicated.
1133 static struct bio *bio_clone_range(struct bio *bio_src,
1134 unsigned int offset,
1142 unsigned short end_idx;
1143 unsigned short vcnt;
1146 /* Handle the easy case for the caller */
1148 if (!offset && len == bio_src->bi_size)
1149 return bio_clone(bio_src, gfpmask);
1151 if (WARN_ON_ONCE(!len))
1153 if (WARN_ON_ONCE(len > bio_src->bi_size))
1155 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1158 /* Find first affected segment... */
1161 __bio_for_each_segment(bv, bio_src, idx, 0) {
1162 if (resid < bv->bv_len)
1164 resid -= bv->bv_len;
1168 /* ...and the last affected segment */
1171 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1172 if (resid <= bv->bv_len)
1174 resid -= bv->bv_len;
1176 vcnt = end_idx - idx + 1;
1178 /* Build the clone */
1180 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1182 return NULL; /* ENOMEM */
1184 bio->bi_bdev = bio_src->bi_bdev;
1185 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1186 bio->bi_rw = bio_src->bi_rw;
1187 bio->bi_flags |= 1 << BIO_CLONED;
1190 * Copy over our part of the bio_vec, then update the first
1191 * and last (or only) entries.
1193 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1194 vcnt * sizeof (struct bio_vec));
1195 bio->bi_io_vec[0].bv_offset += voff;
1197 bio->bi_io_vec[0].bv_len -= voff;
1198 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1200 bio->bi_io_vec[0].bv_len = len;
1203 bio->bi_vcnt = vcnt;
1211 * Clone a portion of a bio chain, starting at the given byte offset
1212 * into the first bio in the source chain and continuing for the
1213 * number of bytes indicated. The result is another bio chain of
1214 * exactly the given length, or a null pointer on error.
1216 * The bio_src and offset parameters are both in-out. On entry they
1217 * refer to the first source bio and the offset into that bio where
1218 * the start of data to be cloned is located.
1220 * On return, bio_src is updated to refer to the bio in the source
1221 * chain that contains first un-cloned byte, and *offset will
1222 * contain the offset of that byte within that bio.
1224 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1225 unsigned int *offset,
1229 struct bio *bi = *bio_src;
1230 unsigned int off = *offset;
1231 struct bio *chain = NULL;
1234 /* Build up a chain of clone bios up to the limit */
1236 if (!bi || off >= bi->bi_size || !len)
1237 return NULL; /* Nothing to clone */
1241 unsigned int bi_size;
1245 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1246 goto out_err; /* EINVAL; ran out of bio's */
1248 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1249 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1251 goto out_err; /* ENOMEM */
1254 end = &bio->bi_next;
1257 if (off == bi->bi_size) {
1268 bio_chain_put(chain);
1274 * The default/initial value for all object request flags is 0. For
1275 * each flag, once its value is set to 1 it is never reset to 0
1278 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1280 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1281 struct rbd_device *rbd_dev;
1283 rbd_dev = obj_request->img_request->rbd_dev;
1284 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1289 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1292 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1295 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1297 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1298 struct rbd_device *rbd_dev = NULL;
1300 if (obj_request_img_data_test(obj_request))
1301 rbd_dev = obj_request->img_request->rbd_dev;
1302 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1307 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1310 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1314 * This sets the KNOWN flag after (possibly) setting the EXISTS
1315 * flag. The latter is set based on the "exists" value provided.
1317 * Note that for our purposes once an object exists it never goes
1318 * away again. It's possible that the response from two existence
1319 * checks are separated by the creation of the target object, and
1320 * the first ("doesn't exist") response arrives *after* the second
1321 * ("does exist"). In that case we ignore the second one.
1323 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1327 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1328 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1332 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1335 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1338 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1341 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1344 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1346 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1347 atomic_read(&obj_request->kref.refcount));
1348 kref_get(&obj_request->kref);
1351 static void rbd_obj_request_destroy(struct kref *kref);
1352 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1354 rbd_assert(obj_request != NULL);
1355 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1356 atomic_read(&obj_request->kref.refcount));
1357 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1360 static void rbd_img_request_destroy(struct kref *kref);
1361 static void rbd_img_request_put(struct rbd_img_request *img_request)
1363 rbd_assert(img_request != NULL);
1364 dout("%s: img %p (was %d)\n", __func__, img_request,
1365 atomic_read(&img_request->kref.refcount));
1366 kref_put(&img_request->kref, rbd_img_request_destroy);
1369 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1370 struct rbd_obj_request *obj_request)
1372 rbd_assert(obj_request->img_request == NULL);
1374 /* Image request now owns object's original reference */
1375 obj_request->img_request = img_request;
1376 obj_request->which = img_request->obj_request_count;
1377 rbd_assert(!obj_request_img_data_test(obj_request));
1378 obj_request_img_data_set(obj_request);
1379 rbd_assert(obj_request->which != BAD_WHICH);
1380 img_request->obj_request_count++;
1381 list_add_tail(&obj_request->links, &img_request->obj_requests);
1382 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1383 obj_request->which);
1386 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1387 struct rbd_obj_request *obj_request)
1389 rbd_assert(obj_request->which != BAD_WHICH);
1391 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1392 obj_request->which);
1393 list_del(&obj_request->links);
1394 rbd_assert(img_request->obj_request_count > 0);
1395 img_request->obj_request_count--;
1396 rbd_assert(obj_request->which == img_request->obj_request_count);
1397 obj_request->which = BAD_WHICH;
1398 rbd_assert(obj_request_img_data_test(obj_request));
1399 rbd_assert(obj_request->img_request == img_request);
1400 obj_request->img_request = NULL;
1401 obj_request->callback = NULL;
1402 rbd_obj_request_put(obj_request);
1405 static bool obj_request_type_valid(enum obj_request_type type)
1408 case OBJ_REQUEST_NODATA:
1409 case OBJ_REQUEST_BIO:
1410 case OBJ_REQUEST_PAGES:
1417 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1418 struct rbd_obj_request *obj_request)
1420 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1422 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1425 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1428 dout("%s: img %p\n", __func__, img_request);
1431 * If no error occurred, compute the aggregate transfer
1432 * count for the image request. We could instead use
1433 * atomic64_cmpxchg() to update it as each object request
1434 * completes; not clear which way is better off hand.
1436 if (!img_request->result) {
1437 struct rbd_obj_request *obj_request;
1440 for_each_obj_request(img_request, obj_request)
1441 xferred += obj_request->xferred;
1442 img_request->xferred = xferred;
1445 if (img_request->callback)
1446 img_request->callback(img_request);
1448 rbd_img_request_put(img_request);
1451 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1453 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1455 dout("%s: obj %p\n", __func__, obj_request);
1457 return wait_for_completion_interruptible(&obj_request->completion);
1461 * The default/initial value for all image request flags is 0. Each
1462 * is conditionally set to 1 at image request initialization time
1463 * and currently never change thereafter.
1465 static void img_request_write_set(struct rbd_img_request *img_request)
1467 set_bit(IMG_REQ_WRITE, &img_request->flags);
1471 static bool img_request_write_test(struct rbd_img_request *img_request)
1474 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1477 static void img_request_child_set(struct rbd_img_request *img_request)
1479 set_bit(IMG_REQ_CHILD, &img_request->flags);
1483 static bool img_request_child_test(struct rbd_img_request *img_request)
1486 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1489 static void img_request_layered_set(struct rbd_img_request *img_request)
1491 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1495 static bool img_request_layered_test(struct rbd_img_request *img_request)
1498 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1502 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1504 u64 xferred = obj_request->xferred;
1505 u64 length = obj_request->length;
1507 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1508 obj_request, obj_request->img_request, obj_request->result,
1511 * ENOENT means a hole in the image. We zero-fill the
1512 * entire length of the request. A short read also implies
1513 * zero-fill to the end of the request. Either way we
1514 * update the xferred count to indicate the whole request
1517 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1518 if (obj_request->result == -ENOENT) {
1519 if (obj_request->type == OBJ_REQUEST_BIO)
1520 zero_bio_chain(obj_request->bio_list, 0);
1522 zero_pages(obj_request->pages, 0, length);
1523 obj_request->result = 0;
1524 obj_request->xferred = length;
1525 } else if (xferred < length && !obj_request->result) {
1526 if (obj_request->type == OBJ_REQUEST_BIO)
1527 zero_bio_chain(obj_request->bio_list, xferred);
1529 zero_pages(obj_request->pages, xferred, length);
1530 obj_request->xferred = length;
1532 obj_request_done_set(obj_request);
1535 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1537 dout("%s: obj %p cb %p\n", __func__, obj_request,
1538 obj_request->callback);
1539 if (obj_request->callback)
1540 obj_request->callback(obj_request);
1542 complete_all(&obj_request->completion);
1545 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1547 dout("%s: obj %p\n", __func__, obj_request);
1548 obj_request_done_set(obj_request);
1551 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1553 struct rbd_img_request *img_request = NULL;
1554 struct rbd_device *rbd_dev = NULL;
1555 bool layered = false;
1557 if (obj_request_img_data_test(obj_request)) {
1558 img_request = obj_request->img_request;
1559 layered = img_request && img_request_layered_test(img_request);
1560 rbd_dev = img_request->rbd_dev;
1563 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1564 obj_request, img_request, obj_request->result,
1565 obj_request->xferred, obj_request->length);
1566 if (layered && obj_request->result == -ENOENT &&
1567 obj_request->img_offset < rbd_dev->parent_overlap)
1568 rbd_img_parent_read(obj_request);
1569 else if (img_request)
1570 rbd_img_obj_request_read_callback(obj_request);
1572 obj_request_done_set(obj_request);
1575 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1577 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1578 obj_request->result, obj_request->length);
1580 * There is no such thing as a successful short write. Set
1581 * it to our originally-requested length.
1583 obj_request->xferred = obj_request->length;
1584 obj_request_done_set(obj_request);
1588 * For a simple stat call there's nothing to do. We'll do more if
1589 * this is part of a write sequence for a layered image.
1591 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1593 dout("%s: obj %p\n", __func__, obj_request);
1594 obj_request_done_set(obj_request);
1597 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1598 struct ceph_msg *msg)
1600 struct rbd_obj_request *obj_request = osd_req->r_priv;
1603 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1604 rbd_assert(osd_req == obj_request->osd_req);
1605 if (obj_request_img_data_test(obj_request)) {
1606 rbd_assert(obj_request->img_request);
1607 rbd_assert(obj_request->which != BAD_WHICH);
1609 rbd_assert(obj_request->which == BAD_WHICH);
1612 if (osd_req->r_result < 0)
1613 obj_request->result = osd_req->r_result;
1615 BUG_ON(osd_req->r_num_ops > 2);
1618 * We support a 64-bit length, but ultimately it has to be
1619 * passed to blk_end_request(), which takes an unsigned int.
1621 obj_request->xferred = osd_req->r_reply_op_len[0];
1622 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1623 opcode = osd_req->r_ops[0].op;
1625 case CEPH_OSD_OP_READ:
1626 rbd_osd_read_callback(obj_request);
1628 case CEPH_OSD_OP_WRITE:
1629 rbd_osd_write_callback(obj_request);
1631 case CEPH_OSD_OP_STAT:
1632 rbd_osd_stat_callback(obj_request);
1634 case CEPH_OSD_OP_CALL:
1635 case CEPH_OSD_OP_NOTIFY_ACK:
1636 case CEPH_OSD_OP_WATCH:
1637 rbd_osd_trivial_callback(obj_request);
1640 rbd_warn(NULL, "%s: unsupported op %hu\n",
1641 obj_request->object_name, (unsigned short) opcode);
1645 if (obj_request_done_test(obj_request))
1646 rbd_obj_request_complete(obj_request);
1649 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1651 struct rbd_img_request *img_request = obj_request->img_request;
1652 struct ceph_osd_request *osd_req = obj_request->osd_req;
1655 rbd_assert(osd_req != NULL);
1657 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1658 ceph_osdc_build_request(osd_req, obj_request->offset,
1659 NULL, snap_id, NULL);
1662 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1664 struct rbd_img_request *img_request = obj_request->img_request;
1665 struct ceph_osd_request *osd_req = obj_request->osd_req;
1666 struct ceph_snap_context *snapc;
1667 struct timespec mtime = CURRENT_TIME;
1669 rbd_assert(osd_req != NULL);
1671 snapc = img_request ? img_request->snapc : NULL;
1672 ceph_osdc_build_request(osd_req, obj_request->offset,
1673 snapc, CEPH_NOSNAP, &mtime);
1676 static struct ceph_osd_request *rbd_osd_req_create(
1677 struct rbd_device *rbd_dev,
1679 struct rbd_obj_request *obj_request)
1681 struct ceph_snap_context *snapc = NULL;
1682 struct ceph_osd_client *osdc;
1683 struct ceph_osd_request *osd_req;
1685 if (obj_request_img_data_test(obj_request)) {
1686 struct rbd_img_request *img_request = obj_request->img_request;
1688 rbd_assert(write_request ==
1689 img_request_write_test(img_request));
1691 snapc = img_request->snapc;
1694 /* Allocate and initialize the request, for the single op */
1696 osdc = &rbd_dev->rbd_client->client->osdc;
1697 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1699 return NULL; /* ENOMEM */
1702 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1704 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1706 osd_req->r_callback = rbd_osd_req_callback;
1707 osd_req->r_priv = obj_request;
1709 osd_req->r_oid_len = strlen(obj_request->object_name);
1710 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1711 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1713 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1719 * Create a copyup osd request based on the information in the
1720 * object request supplied. A copyup request has two osd ops,
1721 * a copyup method call, and a "normal" write request.
1723 static struct ceph_osd_request *
1724 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1726 struct rbd_img_request *img_request;
1727 struct ceph_snap_context *snapc;
1728 struct rbd_device *rbd_dev;
1729 struct ceph_osd_client *osdc;
1730 struct ceph_osd_request *osd_req;
1732 rbd_assert(obj_request_img_data_test(obj_request));
1733 img_request = obj_request->img_request;
1734 rbd_assert(img_request);
1735 rbd_assert(img_request_write_test(img_request));
1737 /* Allocate and initialize the request, for the two ops */
1739 snapc = img_request->snapc;
1740 rbd_dev = img_request->rbd_dev;
1741 osdc = &rbd_dev->rbd_client->client->osdc;
1742 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1744 return NULL; /* ENOMEM */
1746 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1747 osd_req->r_callback = rbd_osd_req_callback;
1748 osd_req->r_priv = obj_request;
1750 osd_req->r_oid_len = strlen(obj_request->object_name);
1751 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1752 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1754 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1760 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1762 ceph_osdc_put_request(osd_req);
1765 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1767 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1768 u64 offset, u64 length,
1769 enum obj_request_type type)
1771 struct rbd_obj_request *obj_request;
1775 rbd_assert(obj_request_type_valid(type));
1777 size = strlen(object_name) + 1;
1778 name = kmalloc(size, GFP_KERNEL);
1782 obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
1788 obj_request->object_name = memcpy(name, object_name, size);
1789 obj_request->offset = offset;
1790 obj_request->length = length;
1791 obj_request->flags = 0;
1792 obj_request->which = BAD_WHICH;
1793 obj_request->type = type;
1794 INIT_LIST_HEAD(&obj_request->links);
1795 init_completion(&obj_request->completion);
1796 kref_init(&obj_request->kref);
1798 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1799 offset, length, (int)type, obj_request);
1804 static void rbd_obj_request_destroy(struct kref *kref)
1806 struct rbd_obj_request *obj_request;
1808 obj_request = container_of(kref, struct rbd_obj_request, kref);
1810 dout("%s: obj %p\n", __func__, obj_request);
1812 rbd_assert(obj_request->img_request == NULL);
1813 rbd_assert(obj_request->which == BAD_WHICH);
1815 if (obj_request->osd_req)
1816 rbd_osd_req_destroy(obj_request->osd_req);
1818 rbd_assert(obj_request_type_valid(obj_request->type));
1819 switch (obj_request->type) {
1820 case OBJ_REQUEST_NODATA:
1821 break; /* Nothing to do */
1822 case OBJ_REQUEST_BIO:
1823 if (obj_request->bio_list)
1824 bio_chain_put(obj_request->bio_list);
1826 case OBJ_REQUEST_PAGES:
1827 if (obj_request->pages)
1828 ceph_release_page_vector(obj_request->pages,
1829 obj_request->page_count);
1833 kfree(obj_request->object_name);
1834 obj_request->object_name = NULL;
1835 kmem_cache_free(rbd_obj_request_cache, obj_request);
1839 * Caller is responsible for filling in the list of object requests
1840 * that comprises the image request, and the Linux request pointer
1841 * (if there is one).
1843 static struct rbd_img_request *rbd_img_request_create(
1844 struct rbd_device *rbd_dev,
1845 u64 offset, u64 length,
1849 struct rbd_img_request *img_request;
1851 img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_ATOMIC);
1855 if (write_request) {
1856 down_read(&rbd_dev->header_rwsem);
1857 ceph_get_snap_context(rbd_dev->header.snapc);
1858 up_read(&rbd_dev->header_rwsem);
1861 img_request->rq = NULL;
1862 img_request->rbd_dev = rbd_dev;
1863 img_request->offset = offset;
1864 img_request->length = length;
1865 img_request->flags = 0;
1866 if (write_request) {
1867 img_request_write_set(img_request);
1868 img_request->snapc = rbd_dev->header.snapc;
1870 img_request->snap_id = rbd_dev->spec->snap_id;
1873 img_request_child_set(img_request);
1874 if (rbd_dev->parent_spec)
1875 img_request_layered_set(img_request);
1876 spin_lock_init(&img_request->completion_lock);
1877 img_request->next_completion = 0;
1878 img_request->callback = NULL;
1879 img_request->result = 0;
1880 img_request->obj_request_count = 0;
1881 INIT_LIST_HEAD(&img_request->obj_requests);
1882 kref_init(&img_request->kref);
1884 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1885 write_request ? "write" : "read", offset, length,
1891 static void rbd_img_request_destroy(struct kref *kref)
1893 struct rbd_img_request *img_request;
1894 struct rbd_obj_request *obj_request;
1895 struct rbd_obj_request *next_obj_request;
1897 img_request = container_of(kref, struct rbd_img_request, kref);
1899 dout("%s: img %p\n", __func__, img_request);
1901 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1902 rbd_img_obj_request_del(img_request, obj_request);
1903 rbd_assert(img_request->obj_request_count == 0);
1905 if (img_request_write_test(img_request))
1906 ceph_put_snap_context(img_request->snapc);
1908 if (img_request_child_test(img_request))
1909 rbd_obj_request_put(img_request->obj_request);
1911 kmem_cache_free(rbd_img_request_cache, img_request);
1914 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
1916 struct rbd_img_request *img_request;
1917 unsigned int xferred;
1921 rbd_assert(obj_request_img_data_test(obj_request));
1922 img_request = obj_request->img_request;
1924 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
1925 xferred = (unsigned int)obj_request->xferred;
1926 result = obj_request->result;
1928 struct rbd_device *rbd_dev = img_request->rbd_dev;
1930 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
1931 img_request_write_test(img_request) ? "write" : "read",
1932 obj_request->length, obj_request->img_offset,
1933 obj_request->offset);
1934 rbd_warn(rbd_dev, " result %d xferred %x\n",
1936 if (!img_request->result)
1937 img_request->result = result;
1940 /* Image object requests don't own their page array */
1942 if (obj_request->type == OBJ_REQUEST_PAGES) {
1943 obj_request->pages = NULL;
1944 obj_request->page_count = 0;
1947 if (img_request_child_test(img_request)) {
1948 rbd_assert(img_request->obj_request != NULL);
1949 more = obj_request->which < img_request->obj_request_count - 1;
1951 rbd_assert(img_request->rq != NULL);
1952 more = blk_end_request(img_request->rq, result, xferred);
1958 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1960 struct rbd_img_request *img_request;
1961 u32 which = obj_request->which;
1964 rbd_assert(obj_request_img_data_test(obj_request));
1965 img_request = obj_request->img_request;
1967 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1968 rbd_assert(img_request != NULL);
1969 rbd_assert(img_request->obj_request_count > 0);
1970 rbd_assert(which != BAD_WHICH);
1971 rbd_assert(which < img_request->obj_request_count);
1972 rbd_assert(which >= img_request->next_completion);
1974 spin_lock_irq(&img_request->completion_lock);
1975 if (which != img_request->next_completion)
1978 for_each_obj_request_from(img_request, obj_request) {
1980 rbd_assert(which < img_request->obj_request_count);
1982 if (!obj_request_done_test(obj_request))
1984 more = rbd_img_obj_end_request(obj_request);
1988 rbd_assert(more ^ (which == img_request->obj_request_count));
1989 img_request->next_completion = which;
1991 spin_unlock_irq(&img_request->completion_lock);
1994 rbd_img_request_complete(img_request);
1998 * Split up an image request into one or more object requests, each
1999 * to a different object. The "type" parameter indicates whether
2000 * "data_desc" is the pointer to the head of a list of bio
2001 * structures, or the base of a page array. In either case this
2002 * function assumes data_desc describes memory sufficient to hold
2003 * all data described by the image request.
2005 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2006 enum obj_request_type type,
2009 struct rbd_device *rbd_dev = img_request->rbd_dev;
2010 struct rbd_obj_request *obj_request = NULL;
2011 struct rbd_obj_request *next_obj_request;
2012 bool write_request = img_request_write_test(img_request);
2013 struct bio *bio_list;
2014 unsigned int bio_offset = 0;
2015 struct page **pages;
2020 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2021 (int)type, data_desc);
2023 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
2024 img_offset = img_request->offset;
2025 resid = img_request->length;
2026 rbd_assert(resid > 0);
2028 if (type == OBJ_REQUEST_BIO) {
2029 bio_list = data_desc;
2030 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
2032 rbd_assert(type == OBJ_REQUEST_PAGES);
2037 struct ceph_osd_request *osd_req;
2038 const char *object_name;
2042 object_name = rbd_segment_name(rbd_dev, img_offset);
2045 offset = rbd_segment_offset(rbd_dev, img_offset);
2046 length = rbd_segment_length(rbd_dev, img_offset, resid);
2047 obj_request = rbd_obj_request_create(object_name,
2048 offset, length, type);
2049 /* object request has its own copy of the object name */
2050 rbd_segment_name_free(object_name);
2054 if (type == OBJ_REQUEST_BIO) {
2055 unsigned int clone_size;
2057 rbd_assert(length <= (u64)UINT_MAX);
2058 clone_size = (unsigned int)length;
2059 obj_request->bio_list =
2060 bio_chain_clone_range(&bio_list,
2064 if (!obj_request->bio_list)
2067 unsigned int page_count;
2069 obj_request->pages = pages;
2070 page_count = (u32)calc_pages_for(offset, length);
2071 obj_request->page_count = page_count;
2072 if ((offset + length) & ~PAGE_MASK)
2073 page_count--; /* more on last page */
2074 pages += page_count;
2077 osd_req = rbd_osd_req_create(rbd_dev, write_request,
2081 obj_request->osd_req = osd_req;
2082 obj_request->callback = rbd_img_obj_callback;
2084 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
2086 if (type == OBJ_REQUEST_BIO)
2087 osd_req_op_extent_osd_data_bio(osd_req, 0,
2088 obj_request->bio_list, length);
2090 osd_req_op_extent_osd_data_pages(osd_req, 0,
2091 obj_request->pages, length,
2092 offset & ~PAGE_MASK, false, false);
2095 rbd_osd_req_format_write(obj_request);
2097 rbd_osd_req_format_read(obj_request);
2099 obj_request->img_offset = img_offset;
2100 rbd_img_obj_request_add(img_request, obj_request);
2102 img_offset += length;
2109 rbd_obj_request_put(obj_request);
2111 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2112 rbd_obj_request_put(obj_request);
2118 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2120 struct rbd_img_request *img_request;
2121 struct rbd_device *rbd_dev;
2125 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2126 rbd_assert(obj_request_img_data_test(obj_request));
2127 img_request = obj_request->img_request;
2128 rbd_assert(img_request);
2130 rbd_dev = img_request->rbd_dev;
2131 rbd_assert(rbd_dev);
2132 length = (u64)1 << rbd_dev->header.obj_order;
2133 page_count = (u32)calc_pages_for(0, length);
2135 rbd_assert(obj_request->copyup_pages);
2136 ceph_release_page_vector(obj_request->copyup_pages, page_count);
2137 obj_request->copyup_pages = NULL;
2140 * We want the transfer count to reflect the size of the
2141 * original write request. There is no such thing as a
2142 * successful short write, so if the request was successful
2143 * we can just set it to the originally-requested length.
2145 if (!obj_request->result)
2146 obj_request->xferred = obj_request->length;
2148 /* Finish up with the normal image object callback */
2150 rbd_img_obj_callback(obj_request);
2154 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2156 struct rbd_obj_request *orig_request;
2157 struct ceph_osd_request *osd_req;
2158 struct ceph_osd_client *osdc;
2159 struct rbd_device *rbd_dev;
2160 struct page **pages;
2165 rbd_assert(img_request_child_test(img_request));
2167 /* First get what we need from the image request */
2169 pages = img_request->copyup_pages;
2170 rbd_assert(pages != NULL);
2171 img_request->copyup_pages = NULL;
2173 orig_request = img_request->obj_request;
2174 rbd_assert(orig_request != NULL);
2175 rbd_assert(orig_request->type == OBJ_REQUEST_BIO);
2176 result = img_request->result;
2177 obj_size = img_request->length;
2178 xferred = img_request->xferred;
2179 rbd_img_request_put(img_request);
2181 rbd_assert(orig_request->img_request);
2182 rbd_dev = orig_request->img_request->rbd_dev;
2183 rbd_assert(rbd_dev);
2184 rbd_assert(obj_size == (u64)1 << rbd_dev->header.obj_order);
2189 /* Allocate the new copyup osd request for the original request */
2192 rbd_assert(!orig_request->osd_req);
2193 osd_req = rbd_osd_req_create_copyup(orig_request);
2196 orig_request->osd_req = osd_req;
2197 orig_request->copyup_pages = pages;
2199 /* Initialize the copyup op */
2201 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2202 osd_req_op_cls_request_data_pages(osd_req, 0, pages, obj_size, 0,
2205 /* Then the original write request op */
2207 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2208 orig_request->offset,
2209 orig_request->length, 0, 0);
2210 osd_req_op_extent_osd_data_bio(osd_req, 1, orig_request->bio_list,
2211 orig_request->length);
2213 rbd_osd_req_format_write(orig_request);
2215 /* All set, send it off. */
2217 orig_request->callback = rbd_img_obj_copyup_callback;
2218 osdc = &rbd_dev->rbd_client->client->osdc;
2219 result = rbd_obj_request_submit(osdc, orig_request);
2223 /* Record the error code and complete the request */
2225 orig_request->result = result;
2226 orig_request->xferred = 0;
2227 obj_request_done_set(orig_request);
2228 rbd_obj_request_complete(orig_request);
2232 * Read from the parent image the range of data that covers the
2233 * entire target of the given object request. This is used for
2234 * satisfying a layered image write request when the target of an
2235 * object request from the image request does not exist.
2237 * A page array big enough to hold the returned data is allocated
2238 * and supplied to rbd_img_request_fill() as the "data descriptor."
2239 * When the read completes, this page array will be transferred to
2240 * the original object request for the copyup operation.
2242 * If an error occurs, record it as the result of the original
2243 * object request and mark it done so it gets completed.
2245 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2247 struct rbd_img_request *img_request = NULL;
2248 struct rbd_img_request *parent_request = NULL;
2249 struct rbd_device *rbd_dev;
2252 struct page **pages = NULL;
2256 rbd_assert(obj_request_img_data_test(obj_request));
2257 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2259 img_request = obj_request->img_request;
2260 rbd_assert(img_request != NULL);
2261 rbd_dev = img_request->rbd_dev;
2262 rbd_assert(rbd_dev->parent != NULL);
2265 * First things first. The original osd request is of no
2266 * use to use any more, we'll need a new one that can hold
2267 * the two ops in a copyup request. We'll get that later,
2268 * but for now we can release the old one.
2270 rbd_osd_req_destroy(obj_request->osd_req);
2271 obj_request->osd_req = NULL;
2274 * Determine the byte range covered by the object in the
2275 * child image to which the original request was to be sent.
2277 img_offset = obj_request->img_offset - obj_request->offset;
2278 length = (u64)1 << rbd_dev->header.obj_order;
2281 * There is no defined parent data beyond the parent
2282 * overlap, so limit what we read at that boundary if
2285 if (img_offset + length > rbd_dev->parent_overlap) {
2286 rbd_assert(img_offset < rbd_dev->parent_overlap);
2287 length = rbd_dev->parent_overlap - img_offset;
2291 * Allocate a page array big enough to receive the data read
2294 page_count = (u32)calc_pages_for(0, length);
2295 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2296 if (IS_ERR(pages)) {
2297 result = PTR_ERR(pages);
2303 parent_request = rbd_img_request_create(rbd_dev->parent,
2306 if (!parent_request)
2308 rbd_obj_request_get(obj_request);
2309 parent_request->obj_request = obj_request;
2311 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2314 parent_request->copyup_pages = pages;
2316 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2317 result = rbd_img_request_submit(parent_request);
2321 parent_request->copyup_pages = NULL;
2322 parent_request->obj_request = NULL;
2323 rbd_obj_request_put(obj_request);
2326 ceph_release_page_vector(pages, page_count);
2328 rbd_img_request_put(parent_request);
2329 obj_request->result = result;
2330 obj_request->xferred = 0;
2331 obj_request_done_set(obj_request);
2336 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2338 struct rbd_obj_request *orig_request;
2341 rbd_assert(!obj_request_img_data_test(obj_request));
2344 * All we need from the object request is the original
2345 * request and the result of the STAT op. Grab those, then
2346 * we're done with the request.
2348 orig_request = obj_request->obj_request;
2349 obj_request->obj_request = NULL;
2350 rbd_assert(orig_request);
2351 rbd_assert(orig_request->img_request);
2353 result = obj_request->result;
2354 obj_request->result = 0;
2356 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2357 obj_request, orig_request, result,
2358 obj_request->xferred, obj_request->length);
2359 rbd_obj_request_put(obj_request);
2361 rbd_assert(orig_request);
2362 rbd_assert(orig_request->img_request);
2365 * Our only purpose here is to determine whether the object
2366 * exists, and we don't want to treat the non-existence as
2367 * an error. If something else comes back, transfer the
2368 * error to the original request and complete it now.
2371 obj_request_existence_set(orig_request, true);
2372 } else if (result == -ENOENT) {
2373 obj_request_existence_set(orig_request, false);
2374 } else if (result) {
2375 orig_request->result = result;
2380 * Resubmit the original request now that we have recorded
2381 * whether the target object exists.
2383 orig_request->result = rbd_img_obj_request_submit(orig_request);
2385 if (orig_request->result)
2386 rbd_obj_request_complete(orig_request);
2387 rbd_obj_request_put(orig_request);
2390 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2392 struct rbd_obj_request *stat_request;
2393 struct rbd_device *rbd_dev;
2394 struct ceph_osd_client *osdc;
2395 struct page **pages = NULL;
2401 * The response data for a STAT call consists of:
2408 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2409 page_count = (u32)calc_pages_for(0, size);
2410 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2412 return PTR_ERR(pages);
2415 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2420 rbd_obj_request_get(obj_request);
2421 stat_request->obj_request = obj_request;
2422 stat_request->pages = pages;
2423 stat_request->page_count = page_count;
2425 rbd_assert(obj_request->img_request);
2426 rbd_dev = obj_request->img_request->rbd_dev;
2427 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2429 if (!stat_request->osd_req)
2431 stat_request->callback = rbd_img_obj_exists_callback;
2433 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2434 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2436 rbd_osd_req_format_read(stat_request);
2438 osdc = &rbd_dev->rbd_client->client->osdc;
2439 ret = rbd_obj_request_submit(osdc, stat_request);
2442 rbd_obj_request_put(obj_request);
2447 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2449 struct rbd_img_request *img_request;
2450 struct rbd_device *rbd_dev;
2453 rbd_assert(obj_request_img_data_test(obj_request));
2455 img_request = obj_request->img_request;
2456 rbd_assert(img_request);
2457 rbd_dev = img_request->rbd_dev;
2460 * Only writes to layered images need special handling.
2461 * Reads and non-layered writes are simple object requests.
2462 * Layered writes that start beyond the end of the overlap
2463 * with the parent have no parent data, so they too are
2464 * simple object requests. Finally, if the target object is
2465 * known to already exist, its parent data has already been
2466 * copied, so a write to the object can also be handled as a
2467 * simple object request.
2469 if (!img_request_write_test(img_request) ||
2470 !img_request_layered_test(img_request) ||
2471 rbd_dev->parent_overlap <= obj_request->img_offset ||
2472 ((known = obj_request_known_test(obj_request)) &&
2473 obj_request_exists_test(obj_request))) {
2475 struct rbd_device *rbd_dev;
2476 struct ceph_osd_client *osdc;
2478 rbd_dev = obj_request->img_request->rbd_dev;
2479 osdc = &rbd_dev->rbd_client->client->osdc;
2481 return rbd_obj_request_submit(osdc, obj_request);
2485 * It's a layered write. The target object might exist but
2486 * we may not know that yet. If we know it doesn't exist,
2487 * start by reading the data for the full target object from
2488 * the parent so we can use it for a copyup to the target.
2491 return rbd_img_obj_parent_read_full(obj_request);
2493 /* We don't know whether the target exists. Go find out. */
2495 return rbd_img_obj_exists_submit(obj_request);
2498 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2500 struct rbd_obj_request *obj_request;
2501 struct rbd_obj_request *next_obj_request;
2503 dout("%s: img %p\n", __func__, img_request);
2504 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2507 ret = rbd_img_obj_request_submit(obj_request);
2515 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2517 struct rbd_obj_request *obj_request;
2518 struct rbd_device *rbd_dev;
2521 rbd_assert(img_request_child_test(img_request));
2523 obj_request = img_request->obj_request;
2524 rbd_assert(obj_request);
2525 rbd_assert(obj_request->img_request);
2527 obj_request->result = img_request->result;
2528 if (obj_request->result)
2532 * We need to zero anything beyond the parent overlap
2533 * boundary. Since rbd_img_obj_request_read_callback()
2534 * will zero anything beyond the end of a short read, an
2535 * easy way to do this is to pretend the data from the
2536 * parent came up short--ending at the overlap boundary.
2538 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2539 obj_end = obj_request->img_offset + obj_request->length;
2540 rbd_dev = obj_request->img_request->rbd_dev;
2541 if (obj_end > rbd_dev->parent_overlap) {
2544 if (obj_request->img_offset < rbd_dev->parent_overlap)
2545 xferred = rbd_dev->parent_overlap -
2546 obj_request->img_offset;
2548 obj_request->xferred = min(img_request->xferred, xferred);
2550 obj_request->xferred = img_request->xferred;
2553 rbd_img_request_put(img_request);
2554 rbd_img_obj_request_read_callback(obj_request);
2555 rbd_obj_request_complete(obj_request);
2558 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2560 struct rbd_device *rbd_dev;
2561 struct rbd_img_request *img_request;
2564 rbd_assert(obj_request_img_data_test(obj_request));
2565 rbd_assert(obj_request->img_request != NULL);
2566 rbd_assert(obj_request->result == (s32) -ENOENT);
2567 rbd_assert(obj_request_type_valid(obj_request->type));
2569 rbd_dev = obj_request->img_request->rbd_dev;
2570 rbd_assert(rbd_dev->parent != NULL);
2571 /* rbd_read_finish(obj_request, obj_request->length); */
2572 img_request = rbd_img_request_create(rbd_dev->parent,
2573 obj_request->img_offset,
2574 obj_request->length,
2580 rbd_obj_request_get(obj_request);
2581 img_request->obj_request = obj_request;
2583 if (obj_request->type == OBJ_REQUEST_BIO)
2584 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2585 obj_request->bio_list);
2587 result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
2588 obj_request->pages);
2592 img_request->callback = rbd_img_parent_read_callback;
2593 result = rbd_img_request_submit(img_request);
2600 rbd_img_request_put(img_request);
2601 obj_request->result = result;
2602 obj_request->xferred = 0;
2603 obj_request_done_set(obj_request);
2606 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
2608 struct rbd_obj_request *obj_request;
2609 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2612 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2613 OBJ_REQUEST_NODATA);
2618 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2619 if (!obj_request->osd_req)
2621 obj_request->callback = rbd_obj_request_put;
2623 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2625 rbd_osd_req_format_read(obj_request);
2627 ret = rbd_obj_request_submit(osdc, obj_request);
2630 rbd_obj_request_put(obj_request);
2635 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2637 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2643 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2644 rbd_dev->header_name, (unsigned long long)notify_id,
2645 (unsigned int)opcode);
2646 ret = rbd_dev_refresh(rbd_dev);
2648 rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);
2650 rbd_obj_notify_ack(rbd_dev, notify_id);
2654 * Request sync osd watch/unwatch. The value of "start" determines
2655 * whether a watch request is being initiated or torn down.
2657 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start)
2659 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2660 struct rbd_obj_request *obj_request;
2663 rbd_assert(start ^ !!rbd_dev->watch_event);
2664 rbd_assert(start ^ !!rbd_dev->watch_request);
2667 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2668 &rbd_dev->watch_event);
2671 rbd_assert(rbd_dev->watch_event != NULL);
2675 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2676 OBJ_REQUEST_NODATA);
2680 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2681 if (!obj_request->osd_req)
2685 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2687 ceph_osdc_unregister_linger_request(osdc,
2688 rbd_dev->watch_request->osd_req);
2690 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2691 rbd_dev->watch_event->cookie, 0, start ? 1 : 0);
2692 rbd_osd_req_format_write(obj_request);
2694 ret = rbd_obj_request_submit(osdc, obj_request);
2697 ret = rbd_obj_request_wait(obj_request);
2700 ret = obj_request->result;
2705 * A watch request is set to linger, so the underlying osd
2706 * request won't go away until we unregister it. We retain
2707 * a pointer to the object request during that time (in
2708 * rbd_dev->watch_request), so we'll keep a reference to
2709 * it. We'll drop that reference (below) after we've
2713 rbd_dev->watch_request = obj_request;
2718 /* We have successfully torn down the watch request */
2720 rbd_obj_request_put(rbd_dev->watch_request);
2721 rbd_dev->watch_request = NULL;
2723 /* Cancel the event if we're tearing down, or on error */
2724 ceph_osdc_cancel_event(rbd_dev->watch_event);
2725 rbd_dev->watch_event = NULL;
2727 rbd_obj_request_put(obj_request);
2733 * Synchronous osd object method call. Returns the number of bytes
2734 * returned in the outbound buffer, or a negative error code.
2736 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2737 const char *object_name,
2738 const char *class_name,
2739 const char *method_name,
2740 const void *outbound,
2741 size_t outbound_size,
2743 size_t inbound_size)
2745 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2746 struct rbd_obj_request *obj_request;
2747 struct page **pages;
2752 * Method calls are ultimately read operations. The result
2753 * should placed into the inbound buffer provided. They
2754 * also supply outbound data--parameters for the object
2755 * method. Currently if this is present it will be a
2758 page_count = (u32)calc_pages_for(0, inbound_size);
2759 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2761 return PTR_ERR(pages);
2764 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2769 obj_request->pages = pages;
2770 obj_request->page_count = page_count;
2772 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2773 if (!obj_request->osd_req)
2776 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2777 class_name, method_name);
2778 if (outbound_size) {
2779 struct ceph_pagelist *pagelist;
2781 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2785 ceph_pagelist_init(pagelist);
2786 ceph_pagelist_append(pagelist, outbound, outbound_size);
2787 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2790 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2791 obj_request->pages, inbound_size,
2793 rbd_osd_req_format_read(obj_request);
2795 ret = rbd_obj_request_submit(osdc, obj_request);
2798 ret = rbd_obj_request_wait(obj_request);
2802 ret = obj_request->result;
2806 rbd_assert(obj_request->xferred < (u64)INT_MAX);
2807 ret = (int)obj_request->xferred;
2808 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
2811 rbd_obj_request_put(obj_request);
2813 ceph_release_page_vector(pages, page_count);
2818 static void rbd_request_fn(struct request_queue *q)
2819 __releases(q->queue_lock) __acquires(q->queue_lock)
2821 struct rbd_device *rbd_dev = q->queuedata;
2822 bool read_only = rbd_dev->mapping.read_only;
2826 while ((rq = blk_fetch_request(q))) {
2827 bool write_request = rq_data_dir(rq) == WRITE;
2828 struct rbd_img_request *img_request;
2832 /* Ignore any non-FS requests that filter through. */
2834 if (rq->cmd_type != REQ_TYPE_FS) {
2835 dout("%s: non-fs request type %d\n", __func__,
2836 (int) rq->cmd_type);
2837 __blk_end_request_all(rq, 0);
2841 /* Ignore/skip any zero-length requests */
2843 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
2844 length = (u64) blk_rq_bytes(rq);
2847 dout("%s: zero-length request\n", __func__);
2848 __blk_end_request_all(rq, 0);
2852 spin_unlock_irq(q->queue_lock);
2854 /* Disallow writes to a read-only device */
2856 if (write_request) {
2860 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
2864 * Quit early if the mapped snapshot no longer
2865 * exists. It's still possible the snapshot will
2866 * have disappeared by the time our request arrives
2867 * at the osd, but there's no sense in sending it if
2870 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
2871 dout("request for non-existent snapshot");
2872 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
2878 if (offset && length > U64_MAX - offset + 1) {
2879 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
2881 goto end_request; /* Shouldn't happen */
2885 if (offset + length > rbd_dev->mapping.size) {
2886 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)\n",
2887 offset, length, rbd_dev->mapping.size);
2892 img_request = rbd_img_request_create(rbd_dev, offset, length,
2893 write_request, false);
2897 img_request->rq = rq;
2899 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2902 result = rbd_img_request_submit(img_request);
2904 rbd_img_request_put(img_request);
2906 spin_lock_irq(q->queue_lock);
2908 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
2909 write_request ? "write" : "read",
2910 length, offset, result);
2912 __blk_end_request_all(rq, result);
2918 * a queue callback. Makes sure that we don't create a bio that spans across
2919 * multiple osd objects. One exception would be with a single page bios,
2920 * which we handle later at bio_chain_clone_range()
2922 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2923 struct bio_vec *bvec)
2925 struct rbd_device *rbd_dev = q->queuedata;
2926 sector_t sector_offset;
2927 sector_t sectors_per_obj;
2928 sector_t obj_sector_offset;
2932 * Find how far into its rbd object the partition-relative
2933 * bio start sector is to offset relative to the enclosing
2936 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2937 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2938 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2941 * Compute the number of bytes from that offset to the end
2942 * of the object. Account for what's already used by the bio.
2944 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2945 if (ret > bmd->bi_size)
2946 ret -= bmd->bi_size;
2951 * Don't send back more than was asked for. And if the bio
2952 * was empty, let the whole thing through because: "Note
2953 * that a block device *must* allow a single page to be
2954 * added to an empty bio."
2956 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2957 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2958 ret = (int) bvec->bv_len;
2963 static void rbd_free_disk(struct rbd_device *rbd_dev)
2965 struct gendisk *disk = rbd_dev->disk;
2970 rbd_dev->disk = NULL;
2971 if (disk->flags & GENHD_FL_UP) {
2974 blk_cleanup_queue(disk->queue);
2979 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2980 const char *object_name,
2981 u64 offset, u64 length, void *buf)
2984 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2985 struct rbd_obj_request *obj_request;
2986 struct page **pages = NULL;
2991 page_count = (u32) calc_pages_for(offset, length);
2992 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2994 ret = PTR_ERR(pages);
2997 obj_request = rbd_obj_request_create(object_name, offset, length,
3002 obj_request->pages = pages;
3003 obj_request->page_count = page_count;
3005 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
3006 if (!obj_request->osd_req)
3009 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
3010 offset, length, 0, 0);
3011 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
3013 obj_request->length,
3014 obj_request->offset & ~PAGE_MASK,
3016 rbd_osd_req_format_read(obj_request);
3018 ret = rbd_obj_request_submit(osdc, obj_request);
3021 ret = rbd_obj_request_wait(obj_request);
3025 ret = obj_request->result;
3029 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
3030 size = (size_t) obj_request->xferred;
3031 ceph_copy_from_page_vector(pages, buf, 0, size);
3032 rbd_assert(size <= (size_t)INT_MAX);
3036 rbd_obj_request_put(obj_request);
3038 ceph_release_page_vector(pages, page_count);
3044 * Read the complete header for the given rbd device. On successful
3045 * return, the rbd_dev->header field will contain up-to-date
3046 * information about the image.
3048 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3050 struct rbd_image_header_ondisk *ondisk = NULL;
3057 * The complete header will include an array of its 64-bit
3058 * snapshot ids, followed by the names of those snapshots as
3059 * a contiguous block of NUL-terminated strings. Note that
3060 * the number of snapshots could change by the time we read
3061 * it in, in which case we re-read it.
3068 size = sizeof (*ondisk);
3069 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
3071 ondisk = kmalloc(size, GFP_KERNEL);
3075 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3079 if ((size_t)ret < size) {
3081 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
3085 if (!rbd_dev_ondisk_valid(ondisk)) {
3087 rbd_warn(rbd_dev, "invalid header");
3091 names_size = le64_to_cpu(ondisk->snap_names_len);
3092 want_count = snap_count;
3093 snap_count = le32_to_cpu(ondisk->snap_count);
3094 } while (snap_count != want_count);
3096 ret = rbd_header_from_disk(rbd_dev, ondisk);
3104 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
3105 * has disappeared from the (just updated) snapshot context.
3107 static void rbd_exists_validate(struct rbd_device *rbd_dev)
3111 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
3114 snap_id = rbd_dev->spec->snap_id;
3115 if (snap_id == CEPH_NOSNAP)
3118 if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
3119 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3122 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3127 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3128 mapping_size = rbd_dev->mapping.size;
3129 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3130 if (rbd_dev->image_format == 1)
3131 ret = rbd_dev_v1_header_info(rbd_dev);
3133 ret = rbd_dev_v2_header_info(rbd_dev);
3135 /* If it's a mapped snapshot, validate its EXISTS flag */
3137 rbd_exists_validate(rbd_dev);
3138 mutex_unlock(&ctl_mutex);
3139 if (mapping_size != rbd_dev->mapping.size) {
3142 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3143 dout("setting size to %llu sectors", (unsigned long long)size);
3144 set_capacity(rbd_dev->disk, size);
3145 revalidate_disk(rbd_dev->disk);
3151 static int rbd_init_disk(struct rbd_device *rbd_dev)
3153 struct gendisk *disk;
3154 struct request_queue *q;
3157 /* create gendisk info */
3158 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3162 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3164 disk->major = rbd_dev->major;
3165 disk->first_minor = 0;
3166 disk->fops = &rbd_bd_ops;
3167 disk->private_data = rbd_dev;
3169 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3173 /* We use the default size, but let's be explicit about it. */
3174 blk_queue_physical_block_size(q, SECTOR_SIZE);
3176 /* set io sizes to object size */
3177 segment_size = rbd_obj_bytes(&rbd_dev->header);
3178 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3179 blk_queue_max_segment_size(q, segment_size);
3180 blk_queue_io_min(q, segment_size);
3181 blk_queue_io_opt(q, segment_size);
3183 blk_queue_merge_bvec(q, rbd_merge_bvec);
3186 q->queuedata = rbd_dev;
3188 rbd_dev->disk = disk;
3201 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3203 return container_of(dev, struct rbd_device, dev);
3206 static ssize_t rbd_size_show(struct device *dev,
3207 struct device_attribute *attr, char *buf)
3209 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3211 return sprintf(buf, "%llu\n",
3212 (unsigned long long)rbd_dev->mapping.size);
3216 * Note this shows the features for whatever's mapped, which is not
3217 * necessarily the base image.
3219 static ssize_t rbd_features_show(struct device *dev,
3220 struct device_attribute *attr, char *buf)
3222 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3224 return sprintf(buf, "0x%016llx\n",
3225 (unsigned long long)rbd_dev->mapping.features);
3228 static ssize_t rbd_major_show(struct device *dev,
3229 struct device_attribute *attr, char *buf)
3231 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3234 return sprintf(buf, "%d\n", rbd_dev->major);
3236 return sprintf(buf, "(none)\n");
3240 static ssize_t rbd_client_id_show(struct device *dev,
3241 struct device_attribute *attr, char *buf)
3243 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3245 return sprintf(buf, "client%lld\n",
3246 ceph_client_id(rbd_dev->rbd_client->client));
3249 static ssize_t rbd_pool_show(struct device *dev,
3250 struct device_attribute *attr, char *buf)
3252 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3254 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3257 static ssize_t rbd_pool_id_show(struct device *dev,
3258 struct device_attribute *attr, char *buf)
3260 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3262 return sprintf(buf, "%llu\n",
3263 (unsigned long long) rbd_dev->spec->pool_id);
3266 static ssize_t rbd_name_show(struct device *dev,
3267 struct device_attribute *attr, char *buf)
3269 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3271 if (rbd_dev->spec->image_name)
3272 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3274 return sprintf(buf, "(unknown)\n");
3277 static ssize_t rbd_image_id_show(struct device *dev,
3278 struct device_attribute *attr, char *buf)
3280 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3282 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3286 * Shows the name of the currently-mapped snapshot (or
3287 * RBD_SNAP_HEAD_NAME for the base image).
3289 static ssize_t rbd_snap_show(struct device *dev,
3290 struct device_attribute *attr,
3293 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3295 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3299 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3300 * for the parent image. If there is no parent, simply shows
3301 * "(no parent image)".
3303 static ssize_t rbd_parent_show(struct device *dev,
3304 struct device_attribute *attr,
3307 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3308 struct rbd_spec *spec = rbd_dev->parent_spec;
3313 return sprintf(buf, "(no parent image)\n");
3315 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3316 (unsigned long long) spec->pool_id, spec->pool_name);
3321 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3322 spec->image_name ? spec->image_name : "(unknown)");
3327 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3328 (unsigned long long) spec->snap_id, spec->snap_name);
3333 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3338 return (ssize_t) (bufp - buf);
3341 static ssize_t rbd_image_refresh(struct device *dev,
3342 struct device_attribute *attr,
3346 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3349 ret = rbd_dev_refresh(rbd_dev);
3351 rbd_warn(rbd_dev, ": manual header refresh error (%d)\n", ret);
3353 return ret < 0 ? ret : size;
3356 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3357 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3358 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3359 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3360 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3361 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3362 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3363 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3364 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3365 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3366 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3368 static struct attribute *rbd_attrs[] = {
3369 &dev_attr_size.attr,
3370 &dev_attr_features.attr,
3371 &dev_attr_major.attr,
3372 &dev_attr_client_id.attr,
3373 &dev_attr_pool.attr,
3374 &dev_attr_pool_id.attr,
3375 &dev_attr_name.attr,
3376 &dev_attr_image_id.attr,
3377 &dev_attr_current_snap.attr,
3378 &dev_attr_parent.attr,
3379 &dev_attr_refresh.attr,
3383 static struct attribute_group rbd_attr_group = {
3387 static const struct attribute_group *rbd_attr_groups[] = {
3392 static void rbd_sysfs_dev_release(struct device *dev)
3396 static struct device_type rbd_device_type = {
3398 .groups = rbd_attr_groups,
3399 .release = rbd_sysfs_dev_release,
3402 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3404 kref_get(&spec->kref);
3409 static void rbd_spec_free(struct kref *kref);
3410 static void rbd_spec_put(struct rbd_spec *spec)
3413 kref_put(&spec->kref, rbd_spec_free);
3416 static struct rbd_spec *rbd_spec_alloc(void)
3418 struct rbd_spec *spec;
3420 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3423 kref_init(&spec->kref);
3428 static void rbd_spec_free(struct kref *kref)
3430 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3432 kfree(spec->pool_name);
3433 kfree(spec->image_id);
3434 kfree(spec->image_name);
3435 kfree(spec->snap_name);
3439 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3440 struct rbd_spec *spec)
3442 struct rbd_device *rbd_dev;
3444 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3448 spin_lock_init(&rbd_dev->lock);
3450 INIT_LIST_HEAD(&rbd_dev->node);
3451 init_rwsem(&rbd_dev->header_rwsem);
3453 rbd_dev->spec = spec;
3454 rbd_dev->rbd_client = rbdc;
3456 /* Initialize the layout used for all rbd requests */
3458 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3459 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3460 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3461 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3466 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3468 rbd_put_client(rbd_dev->rbd_client);
3469 rbd_spec_put(rbd_dev->spec);
3474 * Get the size and object order for an image snapshot, or if
3475 * snap_id is CEPH_NOSNAP, gets this information for the base
3478 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3479 u8 *order, u64 *snap_size)
3481 __le64 snapid = cpu_to_le64(snap_id);
3486 } __attribute__ ((packed)) size_buf = { 0 };
3488 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3490 &snapid, sizeof (snapid),
3491 &size_buf, sizeof (size_buf));
3492 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3495 if (ret < sizeof (size_buf))
3499 *order = size_buf.order;
3500 *snap_size = le64_to_cpu(size_buf.size);
3502 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3503 (unsigned long long)snap_id, (unsigned int)*order,
3504 (unsigned long long)*snap_size);
3509 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3511 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3512 &rbd_dev->header.obj_order,
3513 &rbd_dev->header.image_size);
3516 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3522 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3526 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3527 "rbd", "get_object_prefix", NULL, 0,
3528 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
3529 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3534 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3535 p + ret, NULL, GFP_NOIO);
3538 if (IS_ERR(rbd_dev->header.object_prefix)) {
3539 ret = PTR_ERR(rbd_dev->header.object_prefix);
3540 rbd_dev->header.object_prefix = NULL;
3542 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3550 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3553 __le64 snapid = cpu_to_le64(snap_id);
3557 } __attribute__ ((packed)) features_buf = { 0 };
3561 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3562 "rbd", "get_features",
3563 &snapid, sizeof (snapid),
3564 &features_buf, sizeof (features_buf));
3565 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3568 if (ret < sizeof (features_buf))
3571 incompat = le64_to_cpu(features_buf.incompat);
3572 if (incompat & ~RBD_FEATURES_SUPPORTED)
3575 *snap_features = le64_to_cpu(features_buf.features);
3577 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3578 (unsigned long long)snap_id,
3579 (unsigned long long)*snap_features,
3580 (unsigned long long)le64_to_cpu(features_buf.incompat));
3585 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3587 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3588 &rbd_dev->header.features);
3591 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3593 struct rbd_spec *parent_spec;
3595 void *reply_buf = NULL;
3603 parent_spec = rbd_spec_alloc();
3607 size = sizeof (__le64) + /* pool_id */
3608 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3609 sizeof (__le64) + /* snap_id */
3610 sizeof (__le64); /* overlap */
3611 reply_buf = kmalloc(size, GFP_KERNEL);
3617 snapid = cpu_to_le64(CEPH_NOSNAP);
3618 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3619 "rbd", "get_parent",
3620 &snapid, sizeof (snapid),
3622 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3627 end = reply_buf + ret;
3629 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
3630 if (parent_spec->pool_id == CEPH_NOPOOL)
3631 goto out; /* No parent? No problem. */
3633 /* The ceph file layout needs to fit pool id in 32 bits */
3636 if (parent_spec->pool_id > (u64)U32_MAX) {
3637 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3638 (unsigned long long)parent_spec->pool_id, U32_MAX);
3642 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3643 if (IS_ERR(image_id)) {
3644 ret = PTR_ERR(image_id);
3647 parent_spec->image_id = image_id;
3648 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3649 ceph_decode_64_safe(&p, end, overlap, out_err);
3651 rbd_dev->parent_overlap = overlap;
3652 rbd_dev->parent_spec = parent_spec;
3653 parent_spec = NULL; /* rbd_dev now owns this */
3658 rbd_spec_put(parent_spec);
3663 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3667 __le64 stripe_count;
3668 } __attribute__ ((packed)) striping_info_buf = { 0 };
3669 size_t size = sizeof (striping_info_buf);
3676 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3677 "rbd", "get_stripe_unit_count", NULL, 0,
3678 (char *)&striping_info_buf, size);
3679 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3686 * We don't actually support the "fancy striping" feature
3687 * (STRIPINGV2) yet, but if the striping sizes are the
3688 * defaults the behavior is the same as before. So find
3689 * out, and only fail if the image has non-default values.
3692 obj_size = (u64)1 << rbd_dev->header.obj_order;
3693 p = &striping_info_buf;
3694 stripe_unit = ceph_decode_64(&p);
3695 if (stripe_unit != obj_size) {
3696 rbd_warn(rbd_dev, "unsupported stripe unit "
3697 "(got %llu want %llu)",
3698 stripe_unit, obj_size);
3701 stripe_count = ceph_decode_64(&p);
3702 if (stripe_count != 1) {
3703 rbd_warn(rbd_dev, "unsupported stripe count "
3704 "(got %llu want 1)", stripe_count);
3707 rbd_dev->header.stripe_unit = stripe_unit;
3708 rbd_dev->header.stripe_count = stripe_count;
3713 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3715 size_t image_id_size;
3720 void *reply_buf = NULL;
3722 char *image_name = NULL;
3725 rbd_assert(!rbd_dev->spec->image_name);
3727 len = strlen(rbd_dev->spec->image_id);
3728 image_id_size = sizeof (__le32) + len;
3729 image_id = kmalloc(image_id_size, GFP_KERNEL);
3734 end = image_id + image_id_size;
3735 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3737 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3738 reply_buf = kmalloc(size, GFP_KERNEL);
3742 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3743 "rbd", "dir_get_name",
3744 image_id, image_id_size,
3749 end = reply_buf + ret;
3751 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3752 if (IS_ERR(image_name))
3755 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3763 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3765 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3766 const char *snap_name;
3769 /* Skip over names until we find the one we are looking for */
3771 snap_name = rbd_dev->header.snap_names;
3772 while (which < snapc->num_snaps) {
3773 if (!strcmp(name, snap_name))
3774 return snapc->snaps[which];
3775 snap_name += strlen(snap_name) + 1;
3781 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3783 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3788 for (which = 0; !found && which < snapc->num_snaps; which++) {
3789 const char *snap_name;
3791 snap_id = snapc->snaps[which];
3792 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
3793 if (IS_ERR(snap_name))
3795 found = !strcmp(name, snap_name);
3798 return found ? snap_id : CEPH_NOSNAP;
3802 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
3803 * no snapshot by that name is found, or if an error occurs.
3805 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3807 if (rbd_dev->image_format == 1)
3808 return rbd_v1_snap_id_by_name(rbd_dev, name);
3810 return rbd_v2_snap_id_by_name(rbd_dev, name);
3814 * When an rbd image has a parent image, it is identified by the
3815 * pool, image, and snapshot ids (not names). This function fills
3816 * in the names for those ids. (It's OK if we can't figure out the
3817 * name for an image id, but the pool and snapshot ids should always
3818 * exist and have names.) All names in an rbd spec are dynamically
3821 * When an image being mapped (not a parent) is probed, we have the
3822 * pool name and pool id, image name and image id, and the snapshot
3823 * name. The only thing we're missing is the snapshot id.
3825 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
3827 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3828 struct rbd_spec *spec = rbd_dev->spec;
3829 const char *pool_name;
3830 const char *image_name;
3831 const char *snap_name;
3835 * An image being mapped will have the pool name (etc.), but
3836 * we need to look up the snapshot id.
3838 if (spec->pool_name) {
3839 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
3842 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
3843 if (snap_id == CEPH_NOSNAP)
3845 spec->snap_id = snap_id;
3847 spec->snap_id = CEPH_NOSNAP;
3853 /* Get the pool name; we have to make our own copy of this */
3855 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
3857 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
3860 pool_name = kstrdup(pool_name, GFP_KERNEL);
3864 /* Fetch the image name; tolerate failure here */
3866 image_name = rbd_dev_image_name(rbd_dev);
3868 rbd_warn(rbd_dev, "unable to get image name");
3870 /* Look up the snapshot name, and make a copy */
3872 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
3878 spec->pool_name = pool_name;
3879 spec->image_name = image_name;
3880 spec->snap_name = snap_name;
3890 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
3899 struct ceph_snap_context *snapc;
3903 * We'll need room for the seq value (maximum snapshot id),
3904 * snapshot count, and array of that many snapshot ids.
3905 * For now we have a fixed upper limit on the number we're
3906 * prepared to receive.
3908 size = sizeof (__le64) + sizeof (__le32) +
3909 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3910 reply_buf = kzalloc(size, GFP_KERNEL);
3914 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3915 "rbd", "get_snapcontext", NULL, 0,
3917 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3922 end = reply_buf + ret;
3924 ceph_decode_64_safe(&p, end, seq, out);
3925 ceph_decode_32_safe(&p, end, snap_count, out);
3928 * Make sure the reported number of snapshot ids wouldn't go
3929 * beyond the end of our buffer. But before checking that,
3930 * make sure the computed size of the snapshot context we
3931 * allocate is representable in a size_t.
3933 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
3938 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
3942 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
3948 for (i = 0; i < snap_count; i++)
3949 snapc->snaps[i] = ceph_decode_64(&p);
3951 ceph_put_snap_context(rbd_dev->header.snapc);
3952 rbd_dev->header.snapc = snapc;
3954 dout(" snap context seq = %llu, snap_count = %u\n",
3955 (unsigned long long)seq, (unsigned int)snap_count);
3962 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
3973 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
3974 reply_buf = kmalloc(size, GFP_KERNEL);
3976 return ERR_PTR(-ENOMEM);
3978 snapid = cpu_to_le64(snap_id);
3979 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3980 "rbd", "get_snapshot_name",
3981 &snapid, sizeof (snapid),
3983 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3985 snap_name = ERR_PTR(ret);
3990 end = reply_buf + ret;
3991 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3992 if (IS_ERR(snap_name))
3995 dout(" snap_id 0x%016llx snap_name = %s\n",
3996 (unsigned long long)snap_id, snap_name);
4003 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
4005 bool first_time = rbd_dev->header.object_prefix == NULL;
4008 down_write(&rbd_dev->header_rwsem);
4011 ret = rbd_dev_v2_header_onetime(rbd_dev);
4016 ret = rbd_dev_v2_image_size(rbd_dev);
4019 if (rbd_dev->spec->snap_id == CEPH_NOSNAP)
4020 if (rbd_dev->mapping.size != rbd_dev->header.image_size)
4021 rbd_dev->mapping.size = rbd_dev->header.image_size;
4023 ret = rbd_dev_v2_snap_context(rbd_dev);
4024 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4028 up_write(&rbd_dev->header_rwsem);
4033 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4038 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4040 dev = &rbd_dev->dev;
4041 dev->bus = &rbd_bus_type;
4042 dev->type = &rbd_device_type;
4043 dev->parent = &rbd_root_dev;
4044 dev->release = rbd_dev_device_release;
4045 dev_set_name(dev, "%d", rbd_dev->dev_id);
4046 ret = device_register(dev);
4048 mutex_unlock(&ctl_mutex);
4053 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4055 device_unregister(&rbd_dev->dev);
4058 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4061 * Get a unique rbd identifier for the given new rbd_dev, and add
4062 * the rbd_dev to the global list. The minimum rbd id is 1.
4064 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4066 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4068 spin_lock(&rbd_dev_list_lock);
4069 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4070 spin_unlock(&rbd_dev_list_lock);
4071 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4072 (unsigned long long) rbd_dev->dev_id);
4076 * Remove an rbd_dev from the global list, and record that its
4077 * identifier is no longer in use.
4079 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4081 struct list_head *tmp;
4082 int rbd_id = rbd_dev->dev_id;
4085 rbd_assert(rbd_id > 0);
4087 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4088 (unsigned long long) rbd_dev->dev_id);
4089 spin_lock(&rbd_dev_list_lock);
4090 list_del_init(&rbd_dev->node);
4093 * If the id being "put" is not the current maximum, there
4094 * is nothing special we need to do.
4096 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4097 spin_unlock(&rbd_dev_list_lock);
4102 * We need to update the current maximum id. Search the
4103 * list to find out what it is. We're more likely to find
4104 * the maximum at the end, so search the list backward.
4107 list_for_each_prev(tmp, &rbd_dev_list) {
4108 struct rbd_device *rbd_dev;
4110 rbd_dev = list_entry(tmp, struct rbd_device, node);
4111 if (rbd_dev->dev_id > max_id)
4112 max_id = rbd_dev->dev_id;
4114 spin_unlock(&rbd_dev_list_lock);
4117 * The max id could have been updated by rbd_dev_id_get(), in
4118 * which case it now accurately reflects the new maximum.
4119 * Be careful not to overwrite the maximum value in that
4122 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4123 dout(" max dev id has been reset\n");
4127 * Skips over white space at *buf, and updates *buf to point to the
4128 * first found non-space character (if any). Returns the length of
4129 * the token (string of non-white space characters) found. Note
4130 * that *buf must be terminated with '\0'.
4132 static inline size_t next_token(const char **buf)
4135 * These are the characters that produce nonzero for
4136 * isspace() in the "C" and "POSIX" locales.
4138 const char *spaces = " \f\n\r\t\v";
4140 *buf += strspn(*buf, spaces); /* Find start of token */
4142 return strcspn(*buf, spaces); /* Return token length */
4146 * Finds the next token in *buf, and if the provided token buffer is
4147 * big enough, copies the found token into it. The result, if
4148 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4149 * must be terminated with '\0' on entry.
4151 * Returns the length of the token found (not including the '\0').
4152 * Return value will be 0 if no token is found, and it will be >=
4153 * token_size if the token would not fit.
4155 * The *buf pointer will be updated to point beyond the end of the
4156 * found token. Note that this occurs even if the token buffer is
4157 * too small to hold it.
4159 static inline size_t copy_token(const char **buf,
4165 len = next_token(buf);
4166 if (len < token_size) {
4167 memcpy(token, *buf, len);
4168 *(token + len) = '\0';
4176 * Finds the next token in *buf, dynamically allocates a buffer big
4177 * enough to hold a copy of it, and copies the token into the new
4178 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4179 * that a duplicate buffer is created even for a zero-length token.
4181 * Returns a pointer to the newly-allocated duplicate, or a null
4182 * pointer if memory for the duplicate was not available. If
4183 * the lenp argument is a non-null pointer, the length of the token
4184 * (not including the '\0') is returned in *lenp.
4186 * If successful, the *buf pointer will be updated to point beyond
4187 * the end of the found token.
4189 * Note: uses GFP_KERNEL for allocation.
4191 static inline char *dup_token(const char **buf, size_t *lenp)
4196 len = next_token(buf);
4197 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4200 *(dup + len) = '\0';
4210 * Parse the options provided for an "rbd add" (i.e., rbd image
4211 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4212 * and the data written is passed here via a NUL-terminated buffer.
4213 * Returns 0 if successful or an error code otherwise.
4215 * The information extracted from these options is recorded in
4216 * the other parameters which return dynamically-allocated
4219 * The address of a pointer that will refer to a ceph options
4220 * structure. Caller must release the returned pointer using
4221 * ceph_destroy_options() when it is no longer needed.
4223 * Address of an rbd options pointer. Fully initialized by
4224 * this function; caller must release with kfree().
4226 * Address of an rbd image specification pointer. Fully
4227 * initialized by this function based on parsed options.
4228 * Caller must release with rbd_spec_put().
4230 * The options passed take this form:
4231 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4234 * A comma-separated list of one or more monitor addresses.
4235 * A monitor address is an ip address, optionally followed
4236 * by a port number (separated by a colon).
4237 * I.e.: ip1[:port1][,ip2[:port2]...]
4239 * A comma-separated list of ceph and/or rbd options.
4241 * The name of the rados pool containing the rbd image.
4243 * The name of the image in that pool to map.
4245 * An optional snapshot id. If provided, the mapping will
4246 * present data from the image at the time that snapshot was
4247 * created. The image head is used if no snapshot id is
4248 * provided. Snapshot mappings are always read-only.
4250 static int rbd_add_parse_args(const char *buf,
4251 struct ceph_options **ceph_opts,
4252 struct rbd_options **opts,
4253 struct rbd_spec **rbd_spec)
4257 const char *mon_addrs;
4259 size_t mon_addrs_size;
4260 struct rbd_spec *spec = NULL;
4261 struct rbd_options *rbd_opts = NULL;
4262 struct ceph_options *copts;
4265 /* The first four tokens are required */
4267 len = next_token(&buf);
4269 rbd_warn(NULL, "no monitor address(es) provided");
4273 mon_addrs_size = len + 1;
4277 options = dup_token(&buf, NULL);
4281 rbd_warn(NULL, "no options provided");
4285 spec = rbd_spec_alloc();
4289 spec->pool_name = dup_token(&buf, NULL);
4290 if (!spec->pool_name)
4292 if (!*spec->pool_name) {
4293 rbd_warn(NULL, "no pool name provided");
4297 spec->image_name = dup_token(&buf, NULL);
4298 if (!spec->image_name)
4300 if (!*spec->image_name) {
4301 rbd_warn(NULL, "no image name provided");
4306 * Snapshot name is optional; default is to use "-"
4307 * (indicating the head/no snapshot).
4309 len = next_token(&buf);
4311 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4312 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4313 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4314 ret = -ENAMETOOLONG;
4317 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4320 *(snap_name + len) = '\0';
4321 spec->snap_name = snap_name;
4323 /* Initialize all rbd options to the defaults */
4325 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4329 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4331 copts = ceph_parse_options(options, mon_addrs,
4332 mon_addrs + mon_addrs_size - 1,
4333 parse_rbd_opts_token, rbd_opts);
4334 if (IS_ERR(copts)) {
4335 ret = PTR_ERR(copts);
4356 * An rbd format 2 image has a unique identifier, distinct from the
4357 * name given to it by the user. Internally, that identifier is
4358 * what's used to specify the names of objects related to the image.
4360 * A special "rbd id" object is used to map an rbd image name to its
4361 * id. If that object doesn't exist, then there is no v2 rbd image
4362 * with the supplied name.
4364 * This function will record the given rbd_dev's image_id field if
4365 * it can be determined, and in that case will return 0. If any
4366 * errors occur a negative errno will be returned and the rbd_dev's
4367 * image_id field will be unchanged (and should be NULL).
4369 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4378 * When probing a parent image, the image id is already
4379 * known (and the image name likely is not). There's no
4380 * need to fetch the image id again in this case. We
4381 * do still need to set the image format though.
4383 if (rbd_dev->spec->image_id) {
4384 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4390 * First, see if the format 2 image id file exists, and if
4391 * so, get the image's persistent id from it.
4393 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4394 object_name = kmalloc(size, GFP_NOIO);
4397 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4398 dout("rbd id object name is %s\n", object_name);
4400 /* Response will be an encoded string, which includes a length */
4402 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4403 response = kzalloc(size, GFP_NOIO);
4409 /* If it doesn't exist we'll assume it's a format 1 image */
4411 ret = rbd_obj_method_sync(rbd_dev, object_name,
4412 "rbd", "get_id", NULL, 0,
4413 response, RBD_IMAGE_ID_LEN_MAX);
4414 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4415 if (ret == -ENOENT) {
4416 image_id = kstrdup("", GFP_KERNEL);
4417 ret = image_id ? 0 : -ENOMEM;
4419 rbd_dev->image_format = 1;
4420 } else if (ret > sizeof (__le32)) {
4423 image_id = ceph_extract_encoded_string(&p, p + ret,
4425 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4427 rbd_dev->image_format = 2;
4433 rbd_dev->spec->image_id = image_id;
4434 dout("image_id is %s\n", image_id);
4443 /* Undo whatever state changes are made by v1 or v2 image probe */
4445 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
4447 struct rbd_image_header *header;
4449 rbd_dev_remove_parent(rbd_dev);
4450 rbd_spec_put(rbd_dev->parent_spec);
4451 rbd_dev->parent_spec = NULL;
4452 rbd_dev->parent_overlap = 0;
4454 /* Free dynamic fields from the header, then zero it out */
4456 header = &rbd_dev->header;
4457 ceph_put_snap_context(header->snapc);
4458 kfree(header->snap_sizes);
4459 kfree(header->snap_names);
4460 kfree(header->object_prefix);
4461 memset(header, 0, sizeof (*header));
4464 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
4468 ret = rbd_dev_v2_object_prefix(rbd_dev);
4473 * Get the and check features for the image. Currently the
4474 * features are assumed to never change.
4476 ret = rbd_dev_v2_features(rbd_dev);
4480 /* If the image supports layering, get the parent info */
4482 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
4483 ret = rbd_dev_v2_parent_info(rbd_dev);
4487 * Print a warning if this image has a parent.
4488 * Don't print it if the image now being probed
4489 * is itself a parent. We can tell at this point
4490 * because we won't know its pool name yet (just its
4493 if (rbd_dev->parent_spec && rbd_dev->spec->pool_name)
4494 rbd_warn(rbd_dev, "WARNING: kernel layering "
4495 "is EXPERIMENTAL!");
4498 /* If the image supports fancy striping, get its parameters */
4500 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4501 ret = rbd_dev_v2_striping_info(rbd_dev);
4505 /* No support for crypto and compression type format 2 images */
4509 rbd_dev->parent_overlap = 0;
4510 rbd_spec_put(rbd_dev->parent_spec);
4511 rbd_dev->parent_spec = NULL;
4512 kfree(rbd_dev->header_name);
4513 rbd_dev->header_name = NULL;
4514 kfree(rbd_dev->header.object_prefix);
4515 rbd_dev->header.object_prefix = NULL;
4520 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4522 struct rbd_device *parent = NULL;
4523 struct rbd_spec *parent_spec;
4524 struct rbd_client *rbdc;
4527 if (!rbd_dev->parent_spec)
4530 * We need to pass a reference to the client and the parent
4531 * spec when creating the parent rbd_dev. Images related by
4532 * parent/child relationships always share both.
4534 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4535 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4538 parent = rbd_dev_create(rbdc, parent_spec);
4542 ret = rbd_dev_image_probe(parent, false);
4545 rbd_dev->parent = parent;
4550 rbd_spec_put(rbd_dev->parent_spec);
4551 kfree(rbd_dev->header_name);
4552 rbd_dev_destroy(parent);
4554 rbd_put_client(rbdc);
4555 rbd_spec_put(parent_spec);
4561 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
4565 /* generate unique id: find highest unique id, add one */
4566 rbd_dev_id_get(rbd_dev);
4568 /* Fill in the device name, now that we have its id. */
4569 BUILD_BUG_ON(DEV_NAME_LEN
4570 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4571 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4573 /* Get our block major device number. */
4575 ret = register_blkdev(0, rbd_dev->name);
4578 rbd_dev->major = ret;
4580 /* Set up the blkdev mapping. */
4582 ret = rbd_init_disk(rbd_dev);
4584 goto err_out_blkdev;
4586 ret = rbd_dev_mapping_set(rbd_dev);
4589 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4591 ret = rbd_bus_add_dev(rbd_dev);
4593 goto err_out_mapping;
4595 /* Everything's ready. Announce the disk to the world. */
4597 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4598 add_disk(rbd_dev->disk);
4600 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4601 (unsigned long long) rbd_dev->mapping.size);
4606 rbd_dev_mapping_clear(rbd_dev);
4608 rbd_free_disk(rbd_dev);
4610 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4612 rbd_dev_id_put(rbd_dev);
4613 rbd_dev_mapping_clear(rbd_dev);
4618 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
4620 struct rbd_spec *spec = rbd_dev->spec;
4623 /* Record the header object name for this rbd image. */
4625 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4627 if (rbd_dev->image_format == 1)
4628 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
4630 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
4632 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4633 if (!rbd_dev->header_name)
4636 if (rbd_dev->image_format == 1)
4637 sprintf(rbd_dev->header_name, "%s%s",
4638 spec->image_name, RBD_SUFFIX);
4640 sprintf(rbd_dev->header_name, "%s%s",
4641 RBD_HEADER_PREFIX, spec->image_id);
4645 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
4647 rbd_dev_unprobe(rbd_dev);
4648 kfree(rbd_dev->header_name);
4649 rbd_dev->header_name = NULL;
4650 rbd_dev->image_format = 0;
4651 kfree(rbd_dev->spec->image_id);
4652 rbd_dev->spec->image_id = NULL;
4654 rbd_dev_destroy(rbd_dev);
4658 * Probe for the existence of the header object for the given rbd
4659 * device. If this image is the one being mapped (i.e., not a
4660 * parent), initiate a watch on its header object before using that
4661 * object to get detailed information about the rbd image.
4663 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping)
4669 * Get the id from the image id object. If it's not a
4670 * format 2 image, we'll get ENOENT back, and we'll assume
4671 * it's a format 1 image.
4673 ret = rbd_dev_image_id(rbd_dev);
4676 rbd_assert(rbd_dev->spec->image_id);
4677 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4679 ret = rbd_dev_header_name(rbd_dev);
4681 goto err_out_format;
4684 ret = rbd_dev_header_watch_sync(rbd_dev, true);
4686 goto out_header_name;
4689 if (rbd_dev->image_format == 1)
4690 ret = rbd_dev_v1_header_info(rbd_dev);
4692 ret = rbd_dev_v2_header_info(rbd_dev);
4696 ret = rbd_dev_spec_update(rbd_dev);
4700 ret = rbd_dev_probe_parent(rbd_dev);
4704 dout("discovered format %u image, header name is %s\n",
4705 rbd_dev->image_format, rbd_dev->header_name);
4709 rbd_dev_unprobe(rbd_dev);
4712 tmp = rbd_dev_header_watch_sync(rbd_dev, false);
4714 rbd_warn(rbd_dev, "unable to tear down "
4715 "watch request (%d)\n", tmp);
4718 kfree(rbd_dev->header_name);
4719 rbd_dev->header_name = NULL;
4721 rbd_dev->image_format = 0;
4722 kfree(rbd_dev->spec->image_id);
4723 rbd_dev->spec->image_id = NULL;
4725 dout("probe failed, returning %d\n", ret);
4730 static ssize_t rbd_add(struct bus_type *bus,
4734 struct rbd_device *rbd_dev = NULL;
4735 struct ceph_options *ceph_opts = NULL;
4736 struct rbd_options *rbd_opts = NULL;
4737 struct rbd_spec *spec = NULL;
4738 struct rbd_client *rbdc;
4739 struct ceph_osd_client *osdc;
4743 if (!try_module_get(THIS_MODULE))
4746 /* parse add command */
4747 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4749 goto err_out_module;
4750 read_only = rbd_opts->read_only;
4752 rbd_opts = NULL; /* done with this */
4754 rbdc = rbd_get_client(ceph_opts);
4759 ceph_opts = NULL; /* rbd_dev client now owns this */
4762 osdc = &rbdc->client->osdc;
4763 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4765 goto err_out_client;
4766 spec->pool_id = (u64)rc;
4768 /* The ceph file layout needs to fit pool id in 32 bits */
4770 if (spec->pool_id > (u64)U32_MAX) {
4771 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4772 (unsigned long long)spec->pool_id, U32_MAX);
4774 goto err_out_client;
4777 rbd_dev = rbd_dev_create(rbdc, spec);
4779 goto err_out_client;
4780 rbdc = NULL; /* rbd_dev now owns this */
4781 spec = NULL; /* rbd_dev now owns this */
4783 rc = rbd_dev_image_probe(rbd_dev, true);
4785 goto err_out_rbd_dev;
4787 /* If we are mapping a snapshot it must be marked read-only */
4789 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
4791 rbd_dev->mapping.read_only = read_only;
4793 rc = rbd_dev_device_setup(rbd_dev);
4797 rbd_dev_image_release(rbd_dev);
4799 rbd_dev_destroy(rbd_dev);
4801 rbd_put_client(rbdc);
4804 ceph_destroy_options(ceph_opts);
4808 module_put(THIS_MODULE);
4810 dout("Error adding device %s\n", buf);
4815 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4817 struct list_head *tmp;
4818 struct rbd_device *rbd_dev;
4820 spin_lock(&rbd_dev_list_lock);
4821 list_for_each(tmp, &rbd_dev_list) {
4822 rbd_dev = list_entry(tmp, struct rbd_device, node);
4823 if (rbd_dev->dev_id == dev_id) {
4824 spin_unlock(&rbd_dev_list_lock);
4828 spin_unlock(&rbd_dev_list_lock);
4832 static void rbd_dev_device_release(struct device *dev)
4834 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4836 rbd_free_disk(rbd_dev);
4837 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4838 rbd_dev_mapping_clear(rbd_dev);
4839 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4841 rbd_dev_id_put(rbd_dev);
4842 rbd_dev_mapping_clear(rbd_dev);
4845 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
4847 while (rbd_dev->parent) {
4848 struct rbd_device *first = rbd_dev;
4849 struct rbd_device *second = first->parent;
4850 struct rbd_device *third;
4853 * Follow to the parent with no grandparent and
4856 while (second && (third = second->parent)) {
4861 rbd_dev_image_release(second);
4862 first->parent = NULL;
4863 first->parent_overlap = 0;
4865 rbd_assert(first->parent_spec);
4866 rbd_spec_put(first->parent_spec);
4867 first->parent_spec = NULL;
4871 static ssize_t rbd_remove(struct bus_type *bus,
4875 struct rbd_device *rbd_dev = NULL;
4880 ret = strict_strtoul(buf, 10, &ul);
4884 /* convert to int; abort if we lost anything in the conversion */
4885 target_id = (int) ul;
4886 if (target_id != ul)
4889 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4891 rbd_dev = __rbd_get_dev(target_id);
4897 spin_lock_irq(&rbd_dev->lock);
4898 if (rbd_dev->open_count)
4901 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
4902 spin_unlock_irq(&rbd_dev->lock);
4905 rbd_bus_del_dev(rbd_dev);
4906 ret = rbd_dev_header_watch_sync(rbd_dev, false);
4908 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
4909 rbd_dev_image_release(rbd_dev);
4910 module_put(THIS_MODULE);
4913 mutex_unlock(&ctl_mutex);
4919 * create control files in sysfs
4922 static int rbd_sysfs_init(void)
4926 ret = device_register(&rbd_root_dev);
4930 ret = bus_register(&rbd_bus_type);
4932 device_unregister(&rbd_root_dev);
4937 static void rbd_sysfs_cleanup(void)
4939 bus_unregister(&rbd_bus_type);
4940 device_unregister(&rbd_root_dev);
4943 static int rbd_slab_init(void)
4945 rbd_assert(!rbd_img_request_cache);
4946 rbd_img_request_cache = kmem_cache_create("rbd_img_request",
4947 sizeof (struct rbd_img_request),
4948 __alignof__(struct rbd_img_request),
4950 if (!rbd_img_request_cache)
4953 rbd_assert(!rbd_obj_request_cache);
4954 rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
4955 sizeof (struct rbd_obj_request),
4956 __alignof__(struct rbd_obj_request),
4958 if (!rbd_obj_request_cache)
4961 rbd_assert(!rbd_segment_name_cache);
4962 rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
4963 MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
4964 if (rbd_segment_name_cache)
4967 if (rbd_obj_request_cache) {
4968 kmem_cache_destroy(rbd_obj_request_cache);
4969 rbd_obj_request_cache = NULL;
4972 kmem_cache_destroy(rbd_img_request_cache);
4973 rbd_img_request_cache = NULL;
4978 static void rbd_slab_exit(void)
4980 rbd_assert(rbd_segment_name_cache);
4981 kmem_cache_destroy(rbd_segment_name_cache);
4982 rbd_segment_name_cache = NULL;
4984 rbd_assert(rbd_obj_request_cache);
4985 kmem_cache_destroy(rbd_obj_request_cache);
4986 rbd_obj_request_cache = NULL;
4988 rbd_assert(rbd_img_request_cache);
4989 kmem_cache_destroy(rbd_img_request_cache);
4990 rbd_img_request_cache = NULL;
4993 static int __init rbd_init(void)
4997 if (!libceph_compatible(NULL)) {
4998 rbd_warn(NULL, "libceph incompatibility (quitting)");
5002 rc = rbd_slab_init();
5005 rc = rbd_sysfs_init();
5009 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5014 static void __exit rbd_exit(void)
5016 rbd_sysfs_cleanup();
5020 module_init(rbd_init);
5021 module_exit(rbd_exit);
5023 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5024 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5025 MODULE_DESCRIPTION("rados block device");
5027 /* following authorship retained from original osdblk.c */
5028 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5030 MODULE_LICENSE("GPL");