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;
227 u32 copyup_page_count;
229 struct ceph_osd_request *osd_req;
231 u64 xferred; /* bytes transferred */
234 rbd_obj_callback_t callback;
235 struct completion completion;
241 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
242 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
243 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
246 struct rbd_img_request {
247 struct rbd_device *rbd_dev;
248 u64 offset; /* starting image byte offset */
249 u64 length; /* byte count from offset */
252 u64 snap_id; /* for reads */
253 struct ceph_snap_context *snapc; /* for writes */
256 struct request *rq; /* block request */
257 struct rbd_obj_request *obj_request; /* obj req initiator */
259 struct page **copyup_pages;
260 u32 copyup_page_count;
261 spinlock_t completion_lock;/* protects next_completion */
263 rbd_img_callback_t callback;
264 u64 xferred;/* aggregate bytes transferred */
265 int result; /* first nonzero obj_request result */
267 u32 obj_request_count;
268 struct list_head obj_requests; /* rbd_obj_request structs */
273 #define for_each_obj_request(ireq, oreq) \
274 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
275 #define for_each_obj_request_from(ireq, oreq) \
276 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
277 #define for_each_obj_request_safe(ireq, oreq, n) \
278 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
290 int dev_id; /* blkdev unique id */
292 int major; /* blkdev assigned major */
293 struct gendisk *disk; /* blkdev's gendisk and rq */
295 u32 image_format; /* Either 1 or 2 */
296 struct rbd_client *rbd_client;
298 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
300 spinlock_t lock; /* queue, flags, open_count */
302 struct rbd_image_header header;
303 unsigned long flags; /* possibly lock protected */
304 struct rbd_spec *spec;
308 struct ceph_file_layout layout;
310 struct ceph_osd_event *watch_event;
311 struct rbd_obj_request *watch_request;
313 struct rbd_spec *parent_spec;
315 struct rbd_device *parent;
317 /* protects updating the header */
318 struct rw_semaphore header_rwsem;
320 struct rbd_mapping mapping;
322 struct list_head node;
326 unsigned long open_count; /* protected by lock */
330 * Flag bits for rbd_dev->flags. If atomicity is required,
331 * rbd_dev->lock is used to protect access.
333 * Currently, only the "removing" flag (which is coupled with the
334 * "open_count" field) requires atomic access.
337 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
338 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
341 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
343 static LIST_HEAD(rbd_dev_list); /* devices */
344 static DEFINE_SPINLOCK(rbd_dev_list_lock);
346 static LIST_HEAD(rbd_client_list); /* clients */
347 static DEFINE_SPINLOCK(rbd_client_list_lock);
349 /* Slab caches for frequently-allocated structures */
351 static struct kmem_cache *rbd_img_request_cache;
352 static struct kmem_cache *rbd_obj_request_cache;
353 static struct kmem_cache *rbd_segment_name_cache;
355 static int rbd_img_request_submit(struct rbd_img_request *img_request);
357 static void rbd_dev_device_release(struct device *dev);
359 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
361 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
363 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping);
365 static struct bus_attribute rbd_bus_attrs[] = {
366 __ATTR(add, S_IWUSR, NULL, rbd_add),
367 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
371 static struct bus_type rbd_bus_type = {
373 .bus_attrs = rbd_bus_attrs,
376 static void rbd_root_dev_release(struct device *dev)
380 static struct device rbd_root_dev = {
382 .release = rbd_root_dev_release,
385 static __printf(2, 3)
386 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
388 struct va_format vaf;
396 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
397 else if (rbd_dev->disk)
398 printk(KERN_WARNING "%s: %s: %pV\n",
399 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
400 else if (rbd_dev->spec && rbd_dev->spec->image_name)
401 printk(KERN_WARNING "%s: image %s: %pV\n",
402 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
403 else if (rbd_dev->spec && rbd_dev->spec->image_id)
404 printk(KERN_WARNING "%s: id %s: %pV\n",
405 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
407 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
408 RBD_DRV_NAME, rbd_dev, &vaf);
413 #define rbd_assert(expr) \
414 if (unlikely(!(expr))) { \
415 printk(KERN_ERR "\nAssertion failure in %s() " \
417 "\trbd_assert(%s);\n\n", \
418 __func__, __LINE__, #expr); \
421 #else /* !RBD_DEBUG */
422 # define rbd_assert(expr) ((void) 0)
423 #endif /* !RBD_DEBUG */
425 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
426 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
427 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
429 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
430 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
431 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev);
432 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
434 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
435 u8 *order, u64 *snap_size);
436 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
438 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name);
440 static int rbd_open(struct block_device *bdev, fmode_t mode)
442 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
443 bool removing = false;
445 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
448 spin_lock_irq(&rbd_dev->lock);
449 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
452 rbd_dev->open_count++;
453 spin_unlock_irq(&rbd_dev->lock);
457 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
458 (void) get_device(&rbd_dev->dev);
459 set_device_ro(bdev, rbd_dev->mapping.read_only);
460 mutex_unlock(&ctl_mutex);
465 static int rbd_release(struct gendisk *disk, fmode_t mode)
467 struct rbd_device *rbd_dev = disk->private_data;
468 unsigned long open_count_before;
470 spin_lock_irq(&rbd_dev->lock);
471 open_count_before = rbd_dev->open_count--;
472 spin_unlock_irq(&rbd_dev->lock);
473 rbd_assert(open_count_before > 0);
475 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
476 put_device(&rbd_dev->dev);
477 mutex_unlock(&ctl_mutex);
482 static const struct block_device_operations rbd_bd_ops = {
483 .owner = THIS_MODULE,
485 .release = rbd_release,
489 * Initialize an rbd client instance.
492 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
494 struct rbd_client *rbdc;
497 dout("%s:\n", __func__);
498 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
502 kref_init(&rbdc->kref);
503 INIT_LIST_HEAD(&rbdc->node);
505 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
507 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
508 if (IS_ERR(rbdc->client))
510 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
512 ret = ceph_open_session(rbdc->client);
516 spin_lock(&rbd_client_list_lock);
517 list_add_tail(&rbdc->node, &rbd_client_list);
518 spin_unlock(&rbd_client_list_lock);
520 mutex_unlock(&ctl_mutex);
521 dout("%s: rbdc %p\n", __func__, rbdc);
526 ceph_destroy_client(rbdc->client);
528 mutex_unlock(&ctl_mutex);
532 ceph_destroy_options(ceph_opts);
533 dout("%s: error %d\n", __func__, ret);
538 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
540 kref_get(&rbdc->kref);
546 * Find a ceph client with specific addr and configuration. If
547 * found, bump its reference count.
549 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
551 struct rbd_client *client_node;
554 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
557 spin_lock(&rbd_client_list_lock);
558 list_for_each_entry(client_node, &rbd_client_list, node) {
559 if (!ceph_compare_options(ceph_opts, client_node->client)) {
560 __rbd_get_client(client_node);
566 spin_unlock(&rbd_client_list_lock);
568 return found ? client_node : NULL;
578 /* string args above */
581 /* Boolean args above */
585 static match_table_t rbd_opts_tokens = {
587 /* string args above */
588 {Opt_read_only, "read_only"},
589 {Opt_read_only, "ro"}, /* Alternate spelling */
590 {Opt_read_write, "read_write"},
591 {Opt_read_write, "rw"}, /* Alternate spelling */
592 /* Boolean args above */
600 #define RBD_READ_ONLY_DEFAULT false
602 static int parse_rbd_opts_token(char *c, void *private)
604 struct rbd_options *rbd_opts = private;
605 substring_t argstr[MAX_OPT_ARGS];
606 int token, intval, ret;
608 token = match_token(c, rbd_opts_tokens, argstr);
612 if (token < Opt_last_int) {
613 ret = match_int(&argstr[0], &intval);
615 pr_err("bad mount option arg (not int) "
619 dout("got int token %d val %d\n", token, intval);
620 } else if (token > Opt_last_int && token < Opt_last_string) {
621 dout("got string token %d val %s\n", token,
623 } else if (token > Opt_last_string && token < Opt_last_bool) {
624 dout("got Boolean token %d\n", token);
626 dout("got token %d\n", token);
631 rbd_opts->read_only = true;
634 rbd_opts->read_only = false;
644 * Get a ceph client with specific addr and configuration, if one does
645 * not exist create it.
647 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
649 struct rbd_client *rbdc;
651 rbdc = rbd_client_find(ceph_opts);
652 if (rbdc) /* using an existing client */
653 ceph_destroy_options(ceph_opts);
655 rbdc = rbd_client_create(ceph_opts);
661 * Destroy ceph client
663 * Caller must hold rbd_client_list_lock.
665 static void rbd_client_release(struct kref *kref)
667 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
669 dout("%s: rbdc %p\n", __func__, rbdc);
670 spin_lock(&rbd_client_list_lock);
671 list_del(&rbdc->node);
672 spin_unlock(&rbd_client_list_lock);
674 ceph_destroy_client(rbdc->client);
679 * Drop reference to ceph client node. If it's not referenced anymore, release
682 static void rbd_put_client(struct rbd_client *rbdc)
685 kref_put(&rbdc->kref, rbd_client_release);
688 static bool rbd_image_format_valid(u32 image_format)
690 return image_format == 1 || image_format == 2;
693 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
698 /* The header has to start with the magic rbd header text */
699 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
702 /* The bio layer requires at least sector-sized I/O */
704 if (ondisk->options.order < SECTOR_SHIFT)
707 /* If we use u64 in a few spots we may be able to loosen this */
709 if (ondisk->options.order > 8 * sizeof (int) - 1)
713 * The size of a snapshot header has to fit in a size_t, and
714 * that limits the number of snapshots.
716 snap_count = le32_to_cpu(ondisk->snap_count);
717 size = SIZE_MAX - sizeof (struct ceph_snap_context);
718 if (snap_count > size / sizeof (__le64))
722 * Not only that, but the size of the entire the snapshot
723 * header must also be representable in a size_t.
725 size -= snap_count * sizeof (__le64);
726 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
733 * Fill an rbd image header with information from the given format 1
736 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
737 struct rbd_image_header_ondisk *ondisk)
739 struct rbd_image_header *header = &rbd_dev->header;
740 bool first_time = header->object_prefix == NULL;
741 struct ceph_snap_context *snapc;
742 char *object_prefix = NULL;
743 char *snap_names = NULL;
744 u64 *snap_sizes = NULL;
750 /* Allocate this now to avoid having to handle failure below */
755 len = strnlen(ondisk->object_prefix,
756 sizeof (ondisk->object_prefix));
757 object_prefix = kmalloc(len + 1, GFP_KERNEL);
760 memcpy(object_prefix, ondisk->object_prefix, len);
761 object_prefix[len] = '\0';
764 /* Allocate the snapshot context and fill it in */
766 snap_count = le32_to_cpu(ondisk->snap_count);
767 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
770 snapc->seq = le64_to_cpu(ondisk->snap_seq);
772 struct rbd_image_snap_ondisk *snaps;
773 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
775 /* We'll keep a copy of the snapshot names... */
777 if (snap_names_len > (u64)SIZE_MAX)
779 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
783 /* ...as well as the array of their sizes. */
785 size = snap_count * sizeof (*header->snap_sizes);
786 snap_sizes = kmalloc(size, GFP_KERNEL);
791 * Copy the names, and fill in each snapshot's id
794 * Note that rbd_dev_v1_header_info() guarantees the
795 * ondisk buffer we're working with has
796 * snap_names_len bytes beyond the end of the
797 * snapshot id array, this memcpy() is safe.
799 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
800 snaps = ondisk->snaps;
801 for (i = 0; i < snap_count; i++) {
802 snapc->snaps[i] = le64_to_cpu(snaps[i].id);
803 snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
807 /* We won't fail any more, fill in the header */
809 down_write(&rbd_dev->header_rwsem);
811 header->object_prefix = object_prefix;
812 header->obj_order = ondisk->options.order;
813 header->crypt_type = ondisk->options.crypt_type;
814 header->comp_type = ondisk->options.comp_type;
815 /* The rest aren't used for format 1 images */
816 header->stripe_unit = 0;
817 header->stripe_count = 0;
818 header->features = 0;
820 ceph_put_snap_context(header->snapc);
821 kfree(header->snap_names);
822 kfree(header->snap_sizes);
825 /* The remaining fields always get updated (when we refresh) */
827 header->image_size = le64_to_cpu(ondisk->image_size);
828 header->snapc = snapc;
829 header->snap_names = snap_names;
830 header->snap_sizes = snap_sizes;
832 /* Make sure mapping size is consistent with header info */
834 if (rbd_dev->spec->snap_id == CEPH_NOSNAP || first_time)
835 if (rbd_dev->mapping.size != header->image_size)
836 rbd_dev->mapping.size = header->image_size;
838 up_write(&rbd_dev->header_rwsem);
846 ceph_put_snap_context(snapc);
847 kfree(object_prefix);
852 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
854 const char *snap_name;
856 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
858 /* Skip over names until we find the one we are looking for */
860 snap_name = rbd_dev->header.snap_names;
862 snap_name += strlen(snap_name) + 1;
864 return kstrdup(snap_name, GFP_KERNEL);
868 * Snapshot id comparison function for use with qsort()/bsearch().
869 * Note that result is for snapshots in *descending* order.
871 static int snapid_compare_reverse(const void *s1, const void *s2)
873 u64 snap_id1 = *(u64 *)s1;
874 u64 snap_id2 = *(u64 *)s2;
876 if (snap_id1 < snap_id2)
878 return snap_id1 == snap_id2 ? 0 : -1;
882 * Search a snapshot context to see if the given snapshot id is
885 * Returns the position of the snapshot id in the array if it's found,
886 * or BAD_SNAP_INDEX otherwise.
888 * Note: The snapshot array is in kept sorted (by the osd) in
889 * reverse order, highest snapshot id first.
891 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
893 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
896 found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
897 sizeof (snap_id), snapid_compare_reverse);
899 return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
902 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
907 which = rbd_dev_snap_index(rbd_dev, snap_id);
908 if (which == BAD_SNAP_INDEX)
911 return _rbd_dev_v1_snap_name(rbd_dev, which);
914 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
916 if (snap_id == CEPH_NOSNAP)
917 return RBD_SNAP_HEAD_NAME;
919 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
920 if (rbd_dev->image_format == 1)
921 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
923 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
926 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
929 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
930 if (snap_id == CEPH_NOSNAP) {
931 *snap_size = rbd_dev->header.image_size;
932 } else if (rbd_dev->image_format == 1) {
935 which = rbd_dev_snap_index(rbd_dev, snap_id);
936 if (which == BAD_SNAP_INDEX)
939 *snap_size = rbd_dev->header.snap_sizes[which];
944 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
953 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
956 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
957 if (snap_id == CEPH_NOSNAP) {
958 *snap_features = rbd_dev->header.features;
959 } else if (rbd_dev->image_format == 1) {
960 *snap_features = 0; /* No features for format 1 */
965 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
969 *snap_features = features;
974 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
976 u64 snap_id = rbd_dev->spec->snap_id;
981 ret = rbd_snap_size(rbd_dev, snap_id, &size);
984 ret = rbd_snap_features(rbd_dev, snap_id, &features);
988 rbd_dev->mapping.size = size;
989 rbd_dev->mapping.features = features;
994 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
996 rbd_dev->mapping.size = 0;
997 rbd_dev->mapping.features = 0;
1000 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1006 name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
1009 segment = offset >> rbd_dev->header.obj_order;
1010 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
1011 rbd_dev->header.object_prefix, segment);
1012 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
1013 pr_err("error formatting segment name for #%llu (%d)\n",
1022 static void rbd_segment_name_free(const char *name)
1024 /* The explicit cast here is needed to drop the const qualifier */
1026 kmem_cache_free(rbd_segment_name_cache, (void *)name);
1029 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1031 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1033 return offset & (segment_size - 1);
1036 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1037 u64 offset, u64 length)
1039 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1041 offset &= segment_size - 1;
1043 rbd_assert(length <= U64_MAX - offset);
1044 if (offset + length > segment_size)
1045 length = segment_size - offset;
1051 * returns the size of an object in the image
1053 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1055 return 1 << header->obj_order;
1062 static void bio_chain_put(struct bio *chain)
1068 chain = chain->bi_next;
1074 * zeros a bio chain, starting at specific offset
1076 static void zero_bio_chain(struct bio *chain, int start_ofs)
1079 unsigned long flags;
1085 bio_for_each_segment(bv, chain, i) {
1086 if (pos + bv->bv_len > start_ofs) {
1087 int remainder = max(start_ofs - pos, 0);
1088 buf = bvec_kmap_irq(bv, &flags);
1089 memset(buf + remainder, 0,
1090 bv->bv_len - remainder);
1091 bvec_kunmap_irq(buf, &flags);
1096 chain = chain->bi_next;
1101 * similar to zero_bio_chain(), zeros data defined by a page array,
1102 * starting at the given byte offset from the start of the array and
1103 * continuing up to the given end offset. The pages array is
1104 * assumed to be big enough to hold all bytes up to the end.
1106 static void zero_pages(struct page **pages, u64 offset, u64 end)
1108 struct page **page = &pages[offset >> PAGE_SHIFT];
1110 rbd_assert(end > offset);
1111 rbd_assert(end - offset <= (u64)SIZE_MAX);
1112 while (offset < end) {
1115 unsigned long flags;
1118 page_offset = (size_t)(offset & ~PAGE_MASK);
1119 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1120 local_irq_save(flags);
1121 kaddr = kmap_atomic(*page);
1122 memset(kaddr + page_offset, 0, length);
1123 kunmap_atomic(kaddr);
1124 local_irq_restore(flags);
1132 * Clone a portion of a bio, starting at the given byte offset
1133 * and continuing for the number of bytes indicated.
1135 static struct bio *bio_clone_range(struct bio *bio_src,
1136 unsigned int offset,
1144 unsigned short end_idx;
1145 unsigned short vcnt;
1148 /* Handle the easy case for the caller */
1150 if (!offset && len == bio_src->bi_size)
1151 return bio_clone(bio_src, gfpmask);
1153 if (WARN_ON_ONCE(!len))
1155 if (WARN_ON_ONCE(len > bio_src->bi_size))
1157 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1160 /* Find first affected segment... */
1163 __bio_for_each_segment(bv, bio_src, idx, 0) {
1164 if (resid < bv->bv_len)
1166 resid -= bv->bv_len;
1170 /* ...and the last affected segment */
1173 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1174 if (resid <= bv->bv_len)
1176 resid -= bv->bv_len;
1178 vcnt = end_idx - idx + 1;
1180 /* Build the clone */
1182 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1184 return NULL; /* ENOMEM */
1186 bio->bi_bdev = bio_src->bi_bdev;
1187 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1188 bio->bi_rw = bio_src->bi_rw;
1189 bio->bi_flags |= 1 << BIO_CLONED;
1192 * Copy over our part of the bio_vec, then update the first
1193 * and last (or only) entries.
1195 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1196 vcnt * sizeof (struct bio_vec));
1197 bio->bi_io_vec[0].bv_offset += voff;
1199 bio->bi_io_vec[0].bv_len -= voff;
1200 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1202 bio->bi_io_vec[0].bv_len = len;
1205 bio->bi_vcnt = vcnt;
1213 * Clone a portion of a bio chain, starting at the given byte offset
1214 * into the first bio in the source chain and continuing for the
1215 * number of bytes indicated. The result is another bio chain of
1216 * exactly the given length, or a null pointer on error.
1218 * The bio_src and offset parameters are both in-out. On entry they
1219 * refer to the first source bio and the offset into that bio where
1220 * the start of data to be cloned is located.
1222 * On return, bio_src is updated to refer to the bio in the source
1223 * chain that contains first un-cloned byte, and *offset will
1224 * contain the offset of that byte within that bio.
1226 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1227 unsigned int *offset,
1231 struct bio *bi = *bio_src;
1232 unsigned int off = *offset;
1233 struct bio *chain = NULL;
1236 /* Build up a chain of clone bios up to the limit */
1238 if (!bi || off >= bi->bi_size || !len)
1239 return NULL; /* Nothing to clone */
1243 unsigned int bi_size;
1247 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1248 goto out_err; /* EINVAL; ran out of bio's */
1250 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1251 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1253 goto out_err; /* ENOMEM */
1256 end = &bio->bi_next;
1259 if (off == bi->bi_size) {
1270 bio_chain_put(chain);
1276 * The default/initial value for all object request flags is 0. For
1277 * each flag, once its value is set to 1 it is never reset to 0
1280 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1282 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1283 struct rbd_device *rbd_dev;
1285 rbd_dev = obj_request->img_request->rbd_dev;
1286 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1291 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1294 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1297 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1299 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1300 struct rbd_device *rbd_dev = NULL;
1302 if (obj_request_img_data_test(obj_request))
1303 rbd_dev = obj_request->img_request->rbd_dev;
1304 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1309 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1312 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1316 * This sets the KNOWN flag after (possibly) setting the EXISTS
1317 * flag. The latter is set based on the "exists" value provided.
1319 * Note that for our purposes once an object exists it never goes
1320 * away again. It's possible that the response from two existence
1321 * checks are separated by the creation of the target object, and
1322 * the first ("doesn't exist") response arrives *after* the second
1323 * ("does exist"). In that case we ignore the second one.
1325 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1329 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1330 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1334 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1337 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1340 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1343 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1346 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1348 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1349 atomic_read(&obj_request->kref.refcount));
1350 kref_get(&obj_request->kref);
1353 static void rbd_obj_request_destroy(struct kref *kref);
1354 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1356 rbd_assert(obj_request != NULL);
1357 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1358 atomic_read(&obj_request->kref.refcount));
1359 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1362 static void rbd_img_request_destroy(struct kref *kref);
1363 static void rbd_img_request_put(struct rbd_img_request *img_request)
1365 rbd_assert(img_request != NULL);
1366 dout("%s: img %p (was %d)\n", __func__, img_request,
1367 atomic_read(&img_request->kref.refcount));
1368 kref_put(&img_request->kref, rbd_img_request_destroy);
1371 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1372 struct rbd_obj_request *obj_request)
1374 rbd_assert(obj_request->img_request == NULL);
1376 /* Image request now owns object's original reference */
1377 obj_request->img_request = img_request;
1378 obj_request->which = img_request->obj_request_count;
1379 rbd_assert(!obj_request_img_data_test(obj_request));
1380 obj_request_img_data_set(obj_request);
1381 rbd_assert(obj_request->which != BAD_WHICH);
1382 img_request->obj_request_count++;
1383 list_add_tail(&obj_request->links, &img_request->obj_requests);
1384 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1385 obj_request->which);
1388 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1389 struct rbd_obj_request *obj_request)
1391 rbd_assert(obj_request->which != BAD_WHICH);
1393 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1394 obj_request->which);
1395 list_del(&obj_request->links);
1396 rbd_assert(img_request->obj_request_count > 0);
1397 img_request->obj_request_count--;
1398 rbd_assert(obj_request->which == img_request->obj_request_count);
1399 obj_request->which = BAD_WHICH;
1400 rbd_assert(obj_request_img_data_test(obj_request));
1401 rbd_assert(obj_request->img_request == img_request);
1402 obj_request->img_request = NULL;
1403 obj_request->callback = NULL;
1404 rbd_obj_request_put(obj_request);
1407 static bool obj_request_type_valid(enum obj_request_type type)
1410 case OBJ_REQUEST_NODATA:
1411 case OBJ_REQUEST_BIO:
1412 case OBJ_REQUEST_PAGES:
1419 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1420 struct rbd_obj_request *obj_request)
1422 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1424 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1427 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1430 dout("%s: img %p\n", __func__, img_request);
1433 * If no error occurred, compute the aggregate transfer
1434 * count for the image request. We could instead use
1435 * atomic64_cmpxchg() to update it as each object request
1436 * completes; not clear which way is better off hand.
1438 if (!img_request->result) {
1439 struct rbd_obj_request *obj_request;
1442 for_each_obj_request(img_request, obj_request)
1443 xferred += obj_request->xferred;
1444 img_request->xferred = xferred;
1447 if (img_request->callback)
1448 img_request->callback(img_request);
1450 rbd_img_request_put(img_request);
1453 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1455 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1457 dout("%s: obj %p\n", __func__, obj_request);
1459 return wait_for_completion_interruptible(&obj_request->completion);
1463 * The default/initial value for all image request flags is 0. Each
1464 * is conditionally set to 1 at image request initialization time
1465 * and currently never change thereafter.
1467 static void img_request_write_set(struct rbd_img_request *img_request)
1469 set_bit(IMG_REQ_WRITE, &img_request->flags);
1473 static bool img_request_write_test(struct rbd_img_request *img_request)
1476 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1479 static void img_request_child_set(struct rbd_img_request *img_request)
1481 set_bit(IMG_REQ_CHILD, &img_request->flags);
1485 static bool img_request_child_test(struct rbd_img_request *img_request)
1488 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1491 static void img_request_layered_set(struct rbd_img_request *img_request)
1493 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1497 static bool img_request_layered_test(struct rbd_img_request *img_request)
1500 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1504 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1506 u64 xferred = obj_request->xferred;
1507 u64 length = obj_request->length;
1509 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1510 obj_request, obj_request->img_request, obj_request->result,
1513 * ENOENT means a hole in the image. We zero-fill the
1514 * entire length of the request. A short read also implies
1515 * zero-fill to the end of the request. Either way we
1516 * update the xferred count to indicate the whole request
1519 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1520 if (obj_request->result == -ENOENT) {
1521 if (obj_request->type == OBJ_REQUEST_BIO)
1522 zero_bio_chain(obj_request->bio_list, 0);
1524 zero_pages(obj_request->pages, 0, length);
1525 obj_request->result = 0;
1526 obj_request->xferred = length;
1527 } else if (xferred < length && !obj_request->result) {
1528 if (obj_request->type == OBJ_REQUEST_BIO)
1529 zero_bio_chain(obj_request->bio_list, xferred);
1531 zero_pages(obj_request->pages, xferred, length);
1532 obj_request->xferred = length;
1534 obj_request_done_set(obj_request);
1537 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1539 dout("%s: obj %p cb %p\n", __func__, obj_request,
1540 obj_request->callback);
1541 if (obj_request->callback)
1542 obj_request->callback(obj_request);
1544 complete_all(&obj_request->completion);
1547 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1549 dout("%s: obj %p\n", __func__, obj_request);
1550 obj_request_done_set(obj_request);
1553 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1555 struct rbd_img_request *img_request = NULL;
1556 struct rbd_device *rbd_dev = NULL;
1557 bool layered = false;
1559 if (obj_request_img_data_test(obj_request)) {
1560 img_request = obj_request->img_request;
1561 layered = img_request && img_request_layered_test(img_request);
1562 rbd_dev = img_request->rbd_dev;
1565 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1566 obj_request, img_request, obj_request->result,
1567 obj_request->xferred, obj_request->length);
1568 if (layered && obj_request->result == -ENOENT &&
1569 obj_request->img_offset < rbd_dev->parent_overlap)
1570 rbd_img_parent_read(obj_request);
1571 else if (img_request)
1572 rbd_img_obj_request_read_callback(obj_request);
1574 obj_request_done_set(obj_request);
1577 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1579 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1580 obj_request->result, obj_request->length);
1582 * There is no such thing as a successful short write. Set
1583 * it to our originally-requested length.
1585 obj_request->xferred = obj_request->length;
1586 obj_request_done_set(obj_request);
1590 * For a simple stat call there's nothing to do. We'll do more if
1591 * this is part of a write sequence for a layered image.
1593 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1595 dout("%s: obj %p\n", __func__, obj_request);
1596 obj_request_done_set(obj_request);
1599 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1600 struct ceph_msg *msg)
1602 struct rbd_obj_request *obj_request = osd_req->r_priv;
1605 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1606 rbd_assert(osd_req == obj_request->osd_req);
1607 if (obj_request_img_data_test(obj_request)) {
1608 rbd_assert(obj_request->img_request);
1609 rbd_assert(obj_request->which != BAD_WHICH);
1611 rbd_assert(obj_request->which == BAD_WHICH);
1614 if (osd_req->r_result < 0)
1615 obj_request->result = osd_req->r_result;
1617 BUG_ON(osd_req->r_num_ops > 2);
1620 * We support a 64-bit length, but ultimately it has to be
1621 * passed to blk_end_request(), which takes an unsigned int.
1623 obj_request->xferred = osd_req->r_reply_op_len[0];
1624 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1625 opcode = osd_req->r_ops[0].op;
1627 case CEPH_OSD_OP_READ:
1628 rbd_osd_read_callback(obj_request);
1630 case CEPH_OSD_OP_WRITE:
1631 rbd_osd_write_callback(obj_request);
1633 case CEPH_OSD_OP_STAT:
1634 rbd_osd_stat_callback(obj_request);
1636 case CEPH_OSD_OP_CALL:
1637 case CEPH_OSD_OP_NOTIFY_ACK:
1638 case CEPH_OSD_OP_WATCH:
1639 rbd_osd_trivial_callback(obj_request);
1642 rbd_warn(NULL, "%s: unsupported op %hu\n",
1643 obj_request->object_name, (unsigned short) opcode);
1647 if (obj_request_done_test(obj_request))
1648 rbd_obj_request_complete(obj_request);
1651 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1653 struct rbd_img_request *img_request = obj_request->img_request;
1654 struct ceph_osd_request *osd_req = obj_request->osd_req;
1657 rbd_assert(osd_req != NULL);
1659 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1660 ceph_osdc_build_request(osd_req, obj_request->offset,
1661 NULL, snap_id, NULL);
1664 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1666 struct rbd_img_request *img_request = obj_request->img_request;
1667 struct ceph_osd_request *osd_req = obj_request->osd_req;
1668 struct ceph_snap_context *snapc;
1669 struct timespec mtime = CURRENT_TIME;
1671 rbd_assert(osd_req != NULL);
1673 snapc = img_request ? img_request->snapc : NULL;
1674 ceph_osdc_build_request(osd_req, obj_request->offset,
1675 snapc, CEPH_NOSNAP, &mtime);
1678 static struct ceph_osd_request *rbd_osd_req_create(
1679 struct rbd_device *rbd_dev,
1681 struct rbd_obj_request *obj_request)
1683 struct ceph_snap_context *snapc = NULL;
1684 struct ceph_osd_client *osdc;
1685 struct ceph_osd_request *osd_req;
1687 if (obj_request_img_data_test(obj_request)) {
1688 struct rbd_img_request *img_request = obj_request->img_request;
1690 rbd_assert(write_request ==
1691 img_request_write_test(img_request));
1693 snapc = img_request->snapc;
1696 /* Allocate and initialize the request, for the single op */
1698 osdc = &rbd_dev->rbd_client->client->osdc;
1699 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1701 return NULL; /* ENOMEM */
1704 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1706 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1708 osd_req->r_callback = rbd_osd_req_callback;
1709 osd_req->r_priv = obj_request;
1711 osd_req->r_oid_len = strlen(obj_request->object_name);
1712 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1713 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1715 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1721 * Create a copyup osd request based on the information in the
1722 * object request supplied. A copyup request has two osd ops,
1723 * a copyup method call, and a "normal" write request.
1725 static struct ceph_osd_request *
1726 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1728 struct rbd_img_request *img_request;
1729 struct ceph_snap_context *snapc;
1730 struct rbd_device *rbd_dev;
1731 struct ceph_osd_client *osdc;
1732 struct ceph_osd_request *osd_req;
1734 rbd_assert(obj_request_img_data_test(obj_request));
1735 img_request = obj_request->img_request;
1736 rbd_assert(img_request);
1737 rbd_assert(img_request_write_test(img_request));
1739 /* Allocate and initialize the request, for the two ops */
1741 snapc = img_request->snapc;
1742 rbd_dev = img_request->rbd_dev;
1743 osdc = &rbd_dev->rbd_client->client->osdc;
1744 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1746 return NULL; /* ENOMEM */
1748 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1749 osd_req->r_callback = rbd_osd_req_callback;
1750 osd_req->r_priv = obj_request;
1752 osd_req->r_oid_len = strlen(obj_request->object_name);
1753 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1754 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1756 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1762 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1764 ceph_osdc_put_request(osd_req);
1767 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1769 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1770 u64 offset, u64 length,
1771 enum obj_request_type type)
1773 struct rbd_obj_request *obj_request;
1777 rbd_assert(obj_request_type_valid(type));
1779 size = strlen(object_name) + 1;
1780 name = kmalloc(size, GFP_KERNEL);
1784 obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
1790 obj_request->object_name = memcpy(name, object_name, size);
1791 obj_request->offset = offset;
1792 obj_request->length = length;
1793 obj_request->flags = 0;
1794 obj_request->which = BAD_WHICH;
1795 obj_request->type = type;
1796 INIT_LIST_HEAD(&obj_request->links);
1797 init_completion(&obj_request->completion);
1798 kref_init(&obj_request->kref);
1800 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1801 offset, length, (int)type, obj_request);
1806 static void rbd_obj_request_destroy(struct kref *kref)
1808 struct rbd_obj_request *obj_request;
1810 obj_request = container_of(kref, struct rbd_obj_request, kref);
1812 dout("%s: obj %p\n", __func__, obj_request);
1814 rbd_assert(obj_request->img_request == NULL);
1815 rbd_assert(obj_request->which == BAD_WHICH);
1817 if (obj_request->osd_req)
1818 rbd_osd_req_destroy(obj_request->osd_req);
1820 rbd_assert(obj_request_type_valid(obj_request->type));
1821 switch (obj_request->type) {
1822 case OBJ_REQUEST_NODATA:
1823 break; /* Nothing to do */
1824 case OBJ_REQUEST_BIO:
1825 if (obj_request->bio_list)
1826 bio_chain_put(obj_request->bio_list);
1828 case OBJ_REQUEST_PAGES:
1829 if (obj_request->pages)
1830 ceph_release_page_vector(obj_request->pages,
1831 obj_request->page_count);
1835 kfree(obj_request->object_name);
1836 obj_request->object_name = NULL;
1837 kmem_cache_free(rbd_obj_request_cache, obj_request);
1841 * Caller is responsible for filling in the list of object requests
1842 * that comprises the image request, and the Linux request pointer
1843 * (if there is one).
1845 static struct rbd_img_request *rbd_img_request_create(
1846 struct rbd_device *rbd_dev,
1847 u64 offset, u64 length,
1851 struct rbd_img_request *img_request;
1853 img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_ATOMIC);
1857 if (write_request) {
1858 down_read(&rbd_dev->header_rwsem);
1859 ceph_get_snap_context(rbd_dev->header.snapc);
1860 up_read(&rbd_dev->header_rwsem);
1863 img_request->rq = NULL;
1864 img_request->rbd_dev = rbd_dev;
1865 img_request->offset = offset;
1866 img_request->length = length;
1867 img_request->flags = 0;
1868 if (write_request) {
1869 img_request_write_set(img_request);
1870 img_request->snapc = rbd_dev->header.snapc;
1872 img_request->snap_id = rbd_dev->spec->snap_id;
1875 img_request_child_set(img_request);
1876 if (rbd_dev->parent_spec)
1877 img_request_layered_set(img_request);
1878 spin_lock_init(&img_request->completion_lock);
1879 img_request->next_completion = 0;
1880 img_request->callback = NULL;
1881 img_request->result = 0;
1882 img_request->obj_request_count = 0;
1883 INIT_LIST_HEAD(&img_request->obj_requests);
1884 kref_init(&img_request->kref);
1886 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1887 write_request ? "write" : "read", offset, length,
1893 static void rbd_img_request_destroy(struct kref *kref)
1895 struct rbd_img_request *img_request;
1896 struct rbd_obj_request *obj_request;
1897 struct rbd_obj_request *next_obj_request;
1899 img_request = container_of(kref, struct rbd_img_request, kref);
1901 dout("%s: img %p\n", __func__, img_request);
1903 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1904 rbd_img_obj_request_del(img_request, obj_request);
1905 rbd_assert(img_request->obj_request_count == 0);
1907 if (img_request_write_test(img_request))
1908 ceph_put_snap_context(img_request->snapc);
1910 if (img_request_child_test(img_request))
1911 rbd_obj_request_put(img_request->obj_request);
1913 kmem_cache_free(rbd_img_request_cache, img_request);
1916 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
1918 struct rbd_img_request *img_request;
1919 unsigned int xferred;
1923 rbd_assert(obj_request_img_data_test(obj_request));
1924 img_request = obj_request->img_request;
1926 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
1927 xferred = (unsigned int)obj_request->xferred;
1928 result = obj_request->result;
1930 struct rbd_device *rbd_dev = img_request->rbd_dev;
1932 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
1933 img_request_write_test(img_request) ? "write" : "read",
1934 obj_request->length, obj_request->img_offset,
1935 obj_request->offset);
1936 rbd_warn(rbd_dev, " result %d xferred %x\n",
1938 if (!img_request->result)
1939 img_request->result = result;
1942 /* Image object requests don't own their page array */
1944 if (obj_request->type == OBJ_REQUEST_PAGES) {
1945 obj_request->pages = NULL;
1946 obj_request->page_count = 0;
1949 if (img_request_child_test(img_request)) {
1950 rbd_assert(img_request->obj_request != NULL);
1951 more = obj_request->which < img_request->obj_request_count - 1;
1953 rbd_assert(img_request->rq != NULL);
1954 more = blk_end_request(img_request->rq, result, xferred);
1960 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1962 struct rbd_img_request *img_request;
1963 u32 which = obj_request->which;
1966 rbd_assert(obj_request_img_data_test(obj_request));
1967 img_request = obj_request->img_request;
1969 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1970 rbd_assert(img_request != NULL);
1971 rbd_assert(img_request->obj_request_count > 0);
1972 rbd_assert(which != BAD_WHICH);
1973 rbd_assert(which < img_request->obj_request_count);
1974 rbd_assert(which >= img_request->next_completion);
1976 spin_lock_irq(&img_request->completion_lock);
1977 if (which != img_request->next_completion)
1980 for_each_obj_request_from(img_request, obj_request) {
1982 rbd_assert(which < img_request->obj_request_count);
1984 if (!obj_request_done_test(obj_request))
1986 more = rbd_img_obj_end_request(obj_request);
1990 rbd_assert(more ^ (which == img_request->obj_request_count));
1991 img_request->next_completion = which;
1993 spin_unlock_irq(&img_request->completion_lock);
1996 rbd_img_request_complete(img_request);
2000 * Split up an image request into one or more object requests, each
2001 * to a different object. The "type" parameter indicates whether
2002 * "data_desc" is the pointer to the head of a list of bio
2003 * structures, or the base of a page array. In either case this
2004 * function assumes data_desc describes memory sufficient to hold
2005 * all data described by the image request.
2007 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2008 enum obj_request_type type,
2011 struct rbd_device *rbd_dev = img_request->rbd_dev;
2012 struct rbd_obj_request *obj_request = NULL;
2013 struct rbd_obj_request *next_obj_request;
2014 bool write_request = img_request_write_test(img_request);
2015 struct bio *bio_list;
2016 unsigned int bio_offset = 0;
2017 struct page **pages;
2022 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2023 (int)type, data_desc);
2025 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
2026 img_offset = img_request->offset;
2027 resid = img_request->length;
2028 rbd_assert(resid > 0);
2030 if (type == OBJ_REQUEST_BIO) {
2031 bio_list = data_desc;
2032 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
2034 rbd_assert(type == OBJ_REQUEST_PAGES);
2039 struct ceph_osd_request *osd_req;
2040 const char *object_name;
2044 object_name = rbd_segment_name(rbd_dev, img_offset);
2047 offset = rbd_segment_offset(rbd_dev, img_offset);
2048 length = rbd_segment_length(rbd_dev, img_offset, resid);
2049 obj_request = rbd_obj_request_create(object_name,
2050 offset, length, type);
2051 /* object request has its own copy of the object name */
2052 rbd_segment_name_free(object_name);
2056 if (type == OBJ_REQUEST_BIO) {
2057 unsigned int clone_size;
2059 rbd_assert(length <= (u64)UINT_MAX);
2060 clone_size = (unsigned int)length;
2061 obj_request->bio_list =
2062 bio_chain_clone_range(&bio_list,
2066 if (!obj_request->bio_list)
2069 unsigned int page_count;
2071 obj_request->pages = pages;
2072 page_count = (u32)calc_pages_for(offset, length);
2073 obj_request->page_count = page_count;
2074 if ((offset + length) & ~PAGE_MASK)
2075 page_count--; /* more on last page */
2076 pages += page_count;
2079 osd_req = rbd_osd_req_create(rbd_dev, write_request,
2083 obj_request->osd_req = osd_req;
2084 obj_request->callback = rbd_img_obj_callback;
2086 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
2088 if (type == OBJ_REQUEST_BIO)
2089 osd_req_op_extent_osd_data_bio(osd_req, 0,
2090 obj_request->bio_list, length);
2092 osd_req_op_extent_osd_data_pages(osd_req, 0,
2093 obj_request->pages, length,
2094 offset & ~PAGE_MASK, false, false);
2097 rbd_osd_req_format_write(obj_request);
2099 rbd_osd_req_format_read(obj_request);
2101 obj_request->img_offset = img_offset;
2102 rbd_img_obj_request_add(img_request, obj_request);
2104 img_offset += length;
2111 rbd_obj_request_put(obj_request);
2113 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2114 rbd_obj_request_put(obj_request);
2120 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2122 struct rbd_img_request *img_request;
2123 struct rbd_device *rbd_dev;
2124 struct page **pages;
2127 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2128 rbd_assert(obj_request_img_data_test(obj_request));
2129 img_request = obj_request->img_request;
2130 rbd_assert(img_request);
2132 rbd_dev = img_request->rbd_dev;
2133 rbd_assert(rbd_dev);
2135 pages = obj_request->copyup_pages;
2136 rbd_assert(pages != NULL);
2137 obj_request->copyup_pages = NULL;
2138 page_count = obj_request->copyup_page_count;
2139 rbd_assert(page_count);
2140 obj_request->copyup_page_count = 0;
2141 ceph_release_page_vector(pages, page_count);
2144 * We want the transfer count to reflect the size of the
2145 * original write request. There is no such thing as a
2146 * successful short write, so if the request was successful
2147 * we can just set it to the originally-requested length.
2149 if (!obj_request->result)
2150 obj_request->xferred = obj_request->length;
2152 /* Finish up with the normal image object callback */
2154 rbd_img_obj_callback(obj_request);
2158 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2160 struct rbd_obj_request *orig_request;
2161 struct ceph_osd_request *osd_req;
2162 struct ceph_osd_client *osdc;
2163 struct rbd_device *rbd_dev;
2164 struct page **pages;
2171 rbd_assert(img_request_child_test(img_request));
2173 /* First get what we need from the image request */
2175 pages = img_request->copyup_pages;
2176 rbd_assert(pages != NULL);
2177 img_request->copyup_pages = NULL;
2178 page_count = img_request->copyup_page_count;
2179 rbd_assert(page_count);
2180 img_request->copyup_page_count = 0;
2182 orig_request = img_request->obj_request;
2183 rbd_assert(orig_request != NULL);
2184 rbd_assert(obj_request_type_valid(orig_request->type));
2185 result = img_request->result;
2186 parent_length = img_request->length;
2187 rbd_assert(parent_length == img_request->xferred);
2188 rbd_img_request_put(img_request);
2190 rbd_assert(orig_request->img_request);
2191 rbd_dev = orig_request->img_request->rbd_dev;
2192 rbd_assert(rbd_dev);
2197 /* Allocate the new copyup osd request for the original request */
2200 rbd_assert(!orig_request->osd_req);
2201 osd_req = rbd_osd_req_create_copyup(orig_request);
2204 orig_request->osd_req = osd_req;
2205 orig_request->copyup_pages = pages;
2206 orig_request->copyup_page_count = page_count;
2208 /* Initialize the copyup op */
2210 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2211 osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2214 /* Then the original write request op */
2216 offset = orig_request->offset;
2217 length = orig_request->length;
2218 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2219 offset, length, 0, 0);
2220 if (orig_request->type == OBJ_REQUEST_BIO)
2221 osd_req_op_extent_osd_data_bio(osd_req, 1,
2222 orig_request->bio_list, length);
2224 osd_req_op_extent_osd_data_pages(osd_req, 1,
2225 orig_request->pages, length,
2226 offset & ~PAGE_MASK, false, false);
2228 rbd_osd_req_format_write(orig_request);
2230 /* All set, send it off. */
2232 orig_request->callback = rbd_img_obj_copyup_callback;
2233 osdc = &rbd_dev->rbd_client->client->osdc;
2234 result = rbd_obj_request_submit(osdc, orig_request);
2238 /* Record the error code and complete the request */
2240 orig_request->result = result;
2241 orig_request->xferred = 0;
2242 obj_request_done_set(orig_request);
2243 rbd_obj_request_complete(orig_request);
2247 * Read from the parent image the range of data that covers the
2248 * entire target of the given object request. This is used for
2249 * satisfying a layered image write request when the target of an
2250 * object request from the image request does not exist.
2252 * A page array big enough to hold the returned data is allocated
2253 * and supplied to rbd_img_request_fill() as the "data descriptor."
2254 * When the read completes, this page array will be transferred to
2255 * the original object request for the copyup operation.
2257 * If an error occurs, record it as the result of the original
2258 * object request and mark it done so it gets completed.
2260 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2262 struct rbd_img_request *img_request = NULL;
2263 struct rbd_img_request *parent_request = NULL;
2264 struct rbd_device *rbd_dev;
2267 struct page **pages = NULL;
2271 rbd_assert(obj_request_img_data_test(obj_request));
2272 rbd_assert(obj_request_type_valid(obj_request->type));
2274 img_request = obj_request->img_request;
2275 rbd_assert(img_request != NULL);
2276 rbd_dev = img_request->rbd_dev;
2277 rbd_assert(rbd_dev->parent != NULL);
2280 * First things first. The original osd request is of no
2281 * use to use any more, we'll need a new one that can hold
2282 * the two ops in a copyup request. We'll get that later,
2283 * but for now we can release the old one.
2285 rbd_osd_req_destroy(obj_request->osd_req);
2286 obj_request->osd_req = NULL;
2289 * Determine the byte range covered by the object in the
2290 * child image to which the original request was to be sent.
2292 img_offset = obj_request->img_offset - obj_request->offset;
2293 length = (u64)1 << rbd_dev->header.obj_order;
2296 * There is no defined parent data beyond the parent
2297 * overlap, so limit what we read at that boundary if
2300 if (img_offset + length > rbd_dev->parent_overlap) {
2301 rbd_assert(img_offset < rbd_dev->parent_overlap);
2302 length = rbd_dev->parent_overlap - img_offset;
2306 * Allocate a page array big enough to receive the data read
2309 page_count = (u32)calc_pages_for(0, length);
2310 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2311 if (IS_ERR(pages)) {
2312 result = PTR_ERR(pages);
2318 parent_request = rbd_img_request_create(rbd_dev->parent,
2321 if (!parent_request)
2323 rbd_obj_request_get(obj_request);
2324 parent_request->obj_request = obj_request;
2326 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2329 parent_request->copyup_pages = pages;
2330 parent_request->copyup_page_count = page_count;
2332 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2333 result = rbd_img_request_submit(parent_request);
2337 parent_request->copyup_pages = NULL;
2338 parent_request->copyup_page_count = 0;
2339 parent_request->obj_request = NULL;
2340 rbd_obj_request_put(obj_request);
2343 ceph_release_page_vector(pages, page_count);
2345 rbd_img_request_put(parent_request);
2346 obj_request->result = result;
2347 obj_request->xferred = 0;
2348 obj_request_done_set(obj_request);
2353 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2355 struct rbd_obj_request *orig_request;
2358 rbd_assert(!obj_request_img_data_test(obj_request));
2361 * All we need from the object request is the original
2362 * request and the result of the STAT op. Grab those, then
2363 * we're done with the request.
2365 orig_request = obj_request->obj_request;
2366 obj_request->obj_request = NULL;
2367 rbd_assert(orig_request);
2368 rbd_assert(orig_request->img_request);
2370 result = obj_request->result;
2371 obj_request->result = 0;
2373 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2374 obj_request, orig_request, result,
2375 obj_request->xferred, obj_request->length);
2376 rbd_obj_request_put(obj_request);
2378 rbd_assert(orig_request);
2379 rbd_assert(orig_request->img_request);
2382 * Our only purpose here is to determine whether the object
2383 * exists, and we don't want to treat the non-existence as
2384 * an error. If something else comes back, transfer the
2385 * error to the original request and complete it now.
2388 obj_request_existence_set(orig_request, true);
2389 } else if (result == -ENOENT) {
2390 obj_request_existence_set(orig_request, false);
2391 } else if (result) {
2392 orig_request->result = result;
2397 * Resubmit the original request now that we have recorded
2398 * whether the target object exists.
2400 orig_request->result = rbd_img_obj_request_submit(orig_request);
2402 if (orig_request->result)
2403 rbd_obj_request_complete(orig_request);
2404 rbd_obj_request_put(orig_request);
2407 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2409 struct rbd_obj_request *stat_request;
2410 struct rbd_device *rbd_dev;
2411 struct ceph_osd_client *osdc;
2412 struct page **pages = NULL;
2418 * The response data for a STAT call consists of:
2425 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2426 page_count = (u32)calc_pages_for(0, size);
2427 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2429 return PTR_ERR(pages);
2432 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2437 rbd_obj_request_get(obj_request);
2438 stat_request->obj_request = obj_request;
2439 stat_request->pages = pages;
2440 stat_request->page_count = page_count;
2442 rbd_assert(obj_request->img_request);
2443 rbd_dev = obj_request->img_request->rbd_dev;
2444 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2446 if (!stat_request->osd_req)
2448 stat_request->callback = rbd_img_obj_exists_callback;
2450 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2451 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2453 rbd_osd_req_format_read(stat_request);
2455 osdc = &rbd_dev->rbd_client->client->osdc;
2456 ret = rbd_obj_request_submit(osdc, stat_request);
2459 rbd_obj_request_put(obj_request);
2464 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2466 struct rbd_img_request *img_request;
2467 struct rbd_device *rbd_dev;
2470 rbd_assert(obj_request_img_data_test(obj_request));
2472 img_request = obj_request->img_request;
2473 rbd_assert(img_request);
2474 rbd_dev = img_request->rbd_dev;
2477 * Only writes to layered images need special handling.
2478 * Reads and non-layered writes are simple object requests.
2479 * Layered writes that start beyond the end of the overlap
2480 * with the parent have no parent data, so they too are
2481 * simple object requests. Finally, if the target object is
2482 * known to already exist, its parent data has already been
2483 * copied, so a write to the object can also be handled as a
2484 * simple object request.
2486 if (!img_request_write_test(img_request) ||
2487 !img_request_layered_test(img_request) ||
2488 rbd_dev->parent_overlap <= obj_request->img_offset ||
2489 ((known = obj_request_known_test(obj_request)) &&
2490 obj_request_exists_test(obj_request))) {
2492 struct rbd_device *rbd_dev;
2493 struct ceph_osd_client *osdc;
2495 rbd_dev = obj_request->img_request->rbd_dev;
2496 osdc = &rbd_dev->rbd_client->client->osdc;
2498 return rbd_obj_request_submit(osdc, obj_request);
2502 * It's a layered write. The target object might exist but
2503 * we may not know that yet. If we know it doesn't exist,
2504 * start by reading the data for the full target object from
2505 * the parent so we can use it for a copyup to the target.
2508 return rbd_img_obj_parent_read_full(obj_request);
2510 /* We don't know whether the target exists. Go find out. */
2512 return rbd_img_obj_exists_submit(obj_request);
2515 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2517 struct rbd_obj_request *obj_request;
2518 struct rbd_obj_request *next_obj_request;
2520 dout("%s: img %p\n", __func__, img_request);
2521 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2524 ret = rbd_img_obj_request_submit(obj_request);
2532 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2534 struct rbd_obj_request *obj_request;
2535 struct rbd_device *rbd_dev;
2538 rbd_assert(img_request_child_test(img_request));
2540 obj_request = img_request->obj_request;
2541 rbd_assert(obj_request);
2542 rbd_assert(obj_request->img_request);
2544 obj_request->result = img_request->result;
2545 if (obj_request->result)
2549 * We need to zero anything beyond the parent overlap
2550 * boundary. Since rbd_img_obj_request_read_callback()
2551 * will zero anything beyond the end of a short read, an
2552 * easy way to do this is to pretend the data from the
2553 * parent came up short--ending at the overlap boundary.
2555 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2556 obj_end = obj_request->img_offset + obj_request->length;
2557 rbd_dev = obj_request->img_request->rbd_dev;
2558 if (obj_end > rbd_dev->parent_overlap) {
2561 if (obj_request->img_offset < rbd_dev->parent_overlap)
2562 xferred = rbd_dev->parent_overlap -
2563 obj_request->img_offset;
2565 obj_request->xferred = min(img_request->xferred, xferred);
2567 obj_request->xferred = img_request->xferred;
2570 rbd_img_request_put(img_request);
2571 rbd_img_obj_request_read_callback(obj_request);
2572 rbd_obj_request_complete(obj_request);
2575 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2577 struct rbd_device *rbd_dev;
2578 struct rbd_img_request *img_request;
2581 rbd_assert(obj_request_img_data_test(obj_request));
2582 rbd_assert(obj_request->img_request != NULL);
2583 rbd_assert(obj_request->result == (s32) -ENOENT);
2584 rbd_assert(obj_request_type_valid(obj_request->type));
2586 rbd_dev = obj_request->img_request->rbd_dev;
2587 rbd_assert(rbd_dev->parent != NULL);
2588 /* rbd_read_finish(obj_request, obj_request->length); */
2589 img_request = rbd_img_request_create(rbd_dev->parent,
2590 obj_request->img_offset,
2591 obj_request->length,
2597 rbd_obj_request_get(obj_request);
2598 img_request->obj_request = obj_request;
2600 if (obj_request->type == OBJ_REQUEST_BIO)
2601 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2602 obj_request->bio_list);
2604 result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
2605 obj_request->pages);
2609 img_request->callback = rbd_img_parent_read_callback;
2610 result = rbd_img_request_submit(img_request);
2617 rbd_img_request_put(img_request);
2618 obj_request->result = result;
2619 obj_request->xferred = 0;
2620 obj_request_done_set(obj_request);
2623 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
2625 struct rbd_obj_request *obj_request;
2626 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2629 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2630 OBJ_REQUEST_NODATA);
2635 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2636 if (!obj_request->osd_req)
2638 obj_request->callback = rbd_obj_request_put;
2640 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2642 rbd_osd_req_format_read(obj_request);
2644 ret = rbd_obj_request_submit(osdc, obj_request);
2647 rbd_obj_request_put(obj_request);
2652 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2654 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2660 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2661 rbd_dev->header_name, (unsigned long long)notify_id,
2662 (unsigned int)opcode);
2663 ret = rbd_dev_refresh(rbd_dev);
2665 rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);
2667 rbd_obj_notify_ack(rbd_dev, notify_id);
2671 * Request sync osd watch/unwatch. The value of "start" determines
2672 * whether a watch request is being initiated or torn down.
2674 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start)
2676 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2677 struct rbd_obj_request *obj_request;
2680 rbd_assert(start ^ !!rbd_dev->watch_event);
2681 rbd_assert(start ^ !!rbd_dev->watch_request);
2684 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2685 &rbd_dev->watch_event);
2688 rbd_assert(rbd_dev->watch_event != NULL);
2692 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2693 OBJ_REQUEST_NODATA);
2697 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2698 if (!obj_request->osd_req)
2702 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2704 ceph_osdc_unregister_linger_request(osdc,
2705 rbd_dev->watch_request->osd_req);
2707 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2708 rbd_dev->watch_event->cookie, 0, start ? 1 : 0);
2709 rbd_osd_req_format_write(obj_request);
2711 ret = rbd_obj_request_submit(osdc, obj_request);
2714 ret = rbd_obj_request_wait(obj_request);
2717 ret = obj_request->result;
2722 * A watch request is set to linger, so the underlying osd
2723 * request won't go away until we unregister it. We retain
2724 * a pointer to the object request during that time (in
2725 * rbd_dev->watch_request), so we'll keep a reference to
2726 * it. We'll drop that reference (below) after we've
2730 rbd_dev->watch_request = obj_request;
2735 /* We have successfully torn down the watch request */
2737 rbd_obj_request_put(rbd_dev->watch_request);
2738 rbd_dev->watch_request = NULL;
2740 /* Cancel the event if we're tearing down, or on error */
2741 ceph_osdc_cancel_event(rbd_dev->watch_event);
2742 rbd_dev->watch_event = NULL;
2744 rbd_obj_request_put(obj_request);
2750 * Synchronous osd object method call. Returns the number of bytes
2751 * returned in the outbound buffer, or a negative error code.
2753 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2754 const char *object_name,
2755 const char *class_name,
2756 const char *method_name,
2757 const void *outbound,
2758 size_t outbound_size,
2760 size_t inbound_size)
2762 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2763 struct rbd_obj_request *obj_request;
2764 struct page **pages;
2769 * Method calls are ultimately read operations. The result
2770 * should placed into the inbound buffer provided. They
2771 * also supply outbound data--parameters for the object
2772 * method. Currently if this is present it will be a
2775 page_count = (u32)calc_pages_for(0, inbound_size);
2776 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2778 return PTR_ERR(pages);
2781 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2786 obj_request->pages = pages;
2787 obj_request->page_count = page_count;
2789 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2790 if (!obj_request->osd_req)
2793 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2794 class_name, method_name);
2795 if (outbound_size) {
2796 struct ceph_pagelist *pagelist;
2798 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2802 ceph_pagelist_init(pagelist);
2803 ceph_pagelist_append(pagelist, outbound, outbound_size);
2804 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2807 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2808 obj_request->pages, inbound_size,
2810 rbd_osd_req_format_read(obj_request);
2812 ret = rbd_obj_request_submit(osdc, obj_request);
2815 ret = rbd_obj_request_wait(obj_request);
2819 ret = obj_request->result;
2823 rbd_assert(obj_request->xferred < (u64)INT_MAX);
2824 ret = (int)obj_request->xferred;
2825 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
2828 rbd_obj_request_put(obj_request);
2830 ceph_release_page_vector(pages, page_count);
2835 static void rbd_request_fn(struct request_queue *q)
2836 __releases(q->queue_lock) __acquires(q->queue_lock)
2838 struct rbd_device *rbd_dev = q->queuedata;
2839 bool read_only = rbd_dev->mapping.read_only;
2843 while ((rq = blk_fetch_request(q))) {
2844 bool write_request = rq_data_dir(rq) == WRITE;
2845 struct rbd_img_request *img_request;
2849 /* Ignore any non-FS requests that filter through. */
2851 if (rq->cmd_type != REQ_TYPE_FS) {
2852 dout("%s: non-fs request type %d\n", __func__,
2853 (int) rq->cmd_type);
2854 __blk_end_request_all(rq, 0);
2858 /* Ignore/skip any zero-length requests */
2860 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
2861 length = (u64) blk_rq_bytes(rq);
2864 dout("%s: zero-length request\n", __func__);
2865 __blk_end_request_all(rq, 0);
2869 spin_unlock_irq(q->queue_lock);
2871 /* Disallow writes to a read-only device */
2873 if (write_request) {
2877 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
2881 * Quit early if the mapped snapshot no longer
2882 * exists. It's still possible the snapshot will
2883 * have disappeared by the time our request arrives
2884 * at the osd, but there's no sense in sending it if
2887 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
2888 dout("request for non-existent snapshot");
2889 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
2895 if (offset && length > U64_MAX - offset + 1) {
2896 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
2898 goto end_request; /* Shouldn't happen */
2902 if (offset + length > rbd_dev->mapping.size) {
2903 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)\n",
2904 offset, length, rbd_dev->mapping.size);
2909 img_request = rbd_img_request_create(rbd_dev, offset, length,
2910 write_request, false);
2914 img_request->rq = rq;
2916 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2919 result = rbd_img_request_submit(img_request);
2921 rbd_img_request_put(img_request);
2923 spin_lock_irq(q->queue_lock);
2925 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
2926 write_request ? "write" : "read",
2927 length, offset, result);
2929 __blk_end_request_all(rq, result);
2935 * a queue callback. Makes sure that we don't create a bio that spans across
2936 * multiple osd objects. One exception would be with a single page bios,
2937 * which we handle later at bio_chain_clone_range()
2939 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2940 struct bio_vec *bvec)
2942 struct rbd_device *rbd_dev = q->queuedata;
2943 sector_t sector_offset;
2944 sector_t sectors_per_obj;
2945 sector_t obj_sector_offset;
2949 * Find how far into its rbd object the partition-relative
2950 * bio start sector is to offset relative to the enclosing
2953 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2954 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2955 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2958 * Compute the number of bytes from that offset to the end
2959 * of the object. Account for what's already used by the bio.
2961 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2962 if (ret > bmd->bi_size)
2963 ret -= bmd->bi_size;
2968 * Don't send back more than was asked for. And if the bio
2969 * was empty, let the whole thing through because: "Note
2970 * that a block device *must* allow a single page to be
2971 * added to an empty bio."
2973 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2974 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2975 ret = (int) bvec->bv_len;
2980 static void rbd_free_disk(struct rbd_device *rbd_dev)
2982 struct gendisk *disk = rbd_dev->disk;
2987 rbd_dev->disk = NULL;
2988 if (disk->flags & GENHD_FL_UP) {
2991 blk_cleanup_queue(disk->queue);
2996 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2997 const char *object_name,
2998 u64 offset, u64 length, void *buf)
3001 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3002 struct rbd_obj_request *obj_request;
3003 struct page **pages = NULL;
3008 page_count = (u32) calc_pages_for(offset, length);
3009 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
3011 ret = PTR_ERR(pages);
3014 obj_request = rbd_obj_request_create(object_name, offset, length,
3019 obj_request->pages = pages;
3020 obj_request->page_count = page_count;
3022 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
3023 if (!obj_request->osd_req)
3026 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
3027 offset, length, 0, 0);
3028 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
3030 obj_request->length,
3031 obj_request->offset & ~PAGE_MASK,
3033 rbd_osd_req_format_read(obj_request);
3035 ret = rbd_obj_request_submit(osdc, obj_request);
3038 ret = rbd_obj_request_wait(obj_request);
3042 ret = obj_request->result;
3046 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
3047 size = (size_t) obj_request->xferred;
3048 ceph_copy_from_page_vector(pages, buf, 0, size);
3049 rbd_assert(size <= (size_t)INT_MAX);
3053 rbd_obj_request_put(obj_request);
3055 ceph_release_page_vector(pages, page_count);
3061 * Read the complete header for the given rbd device. On successful
3062 * return, the rbd_dev->header field will contain up-to-date
3063 * information about the image.
3065 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3067 struct rbd_image_header_ondisk *ondisk = NULL;
3074 * The complete header will include an array of its 64-bit
3075 * snapshot ids, followed by the names of those snapshots as
3076 * a contiguous block of NUL-terminated strings. Note that
3077 * the number of snapshots could change by the time we read
3078 * it in, in which case we re-read it.
3085 size = sizeof (*ondisk);
3086 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
3088 ondisk = kmalloc(size, GFP_KERNEL);
3092 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3096 if ((size_t)ret < size) {
3098 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
3102 if (!rbd_dev_ondisk_valid(ondisk)) {
3104 rbd_warn(rbd_dev, "invalid header");
3108 names_size = le64_to_cpu(ondisk->snap_names_len);
3109 want_count = snap_count;
3110 snap_count = le32_to_cpu(ondisk->snap_count);
3111 } while (snap_count != want_count);
3113 ret = rbd_header_from_disk(rbd_dev, ondisk);
3121 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
3122 * has disappeared from the (just updated) snapshot context.
3124 static void rbd_exists_validate(struct rbd_device *rbd_dev)
3128 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
3131 snap_id = rbd_dev->spec->snap_id;
3132 if (snap_id == CEPH_NOSNAP)
3135 if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
3136 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3139 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3144 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3145 mapping_size = rbd_dev->mapping.size;
3146 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3147 if (rbd_dev->image_format == 1)
3148 ret = rbd_dev_v1_header_info(rbd_dev);
3150 ret = rbd_dev_v2_header_info(rbd_dev);
3152 /* If it's a mapped snapshot, validate its EXISTS flag */
3154 rbd_exists_validate(rbd_dev);
3155 mutex_unlock(&ctl_mutex);
3156 if (mapping_size != rbd_dev->mapping.size) {
3159 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3160 dout("setting size to %llu sectors", (unsigned long long)size);
3161 set_capacity(rbd_dev->disk, size);
3162 revalidate_disk(rbd_dev->disk);
3168 static int rbd_init_disk(struct rbd_device *rbd_dev)
3170 struct gendisk *disk;
3171 struct request_queue *q;
3174 /* create gendisk info */
3175 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3179 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3181 disk->major = rbd_dev->major;
3182 disk->first_minor = 0;
3183 disk->fops = &rbd_bd_ops;
3184 disk->private_data = rbd_dev;
3186 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3190 /* We use the default size, but let's be explicit about it. */
3191 blk_queue_physical_block_size(q, SECTOR_SIZE);
3193 /* set io sizes to object size */
3194 segment_size = rbd_obj_bytes(&rbd_dev->header);
3195 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3196 blk_queue_max_segment_size(q, segment_size);
3197 blk_queue_io_min(q, segment_size);
3198 blk_queue_io_opt(q, segment_size);
3200 blk_queue_merge_bvec(q, rbd_merge_bvec);
3203 q->queuedata = rbd_dev;
3205 rbd_dev->disk = disk;
3218 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3220 return container_of(dev, struct rbd_device, dev);
3223 static ssize_t rbd_size_show(struct device *dev,
3224 struct device_attribute *attr, char *buf)
3226 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3228 return sprintf(buf, "%llu\n",
3229 (unsigned long long)rbd_dev->mapping.size);
3233 * Note this shows the features for whatever's mapped, which is not
3234 * necessarily the base image.
3236 static ssize_t rbd_features_show(struct device *dev,
3237 struct device_attribute *attr, char *buf)
3239 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3241 return sprintf(buf, "0x%016llx\n",
3242 (unsigned long long)rbd_dev->mapping.features);
3245 static ssize_t rbd_major_show(struct device *dev,
3246 struct device_attribute *attr, char *buf)
3248 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3251 return sprintf(buf, "%d\n", rbd_dev->major);
3253 return sprintf(buf, "(none)\n");
3257 static ssize_t rbd_client_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, "client%lld\n",
3263 ceph_client_id(rbd_dev->rbd_client->client));
3266 static ssize_t rbd_pool_show(struct device *dev,
3267 struct device_attribute *attr, char *buf)
3269 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3271 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3274 static ssize_t rbd_pool_id_show(struct device *dev,
3275 struct device_attribute *attr, char *buf)
3277 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3279 return sprintf(buf, "%llu\n",
3280 (unsigned long long) rbd_dev->spec->pool_id);
3283 static ssize_t rbd_name_show(struct device *dev,
3284 struct device_attribute *attr, char *buf)
3286 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3288 if (rbd_dev->spec->image_name)
3289 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3291 return sprintf(buf, "(unknown)\n");
3294 static ssize_t rbd_image_id_show(struct device *dev,
3295 struct device_attribute *attr, char *buf)
3297 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3299 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3303 * Shows the name of the currently-mapped snapshot (or
3304 * RBD_SNAP_HEAD_NAME for the base image).
3306 static ssize_t rbd_snap_show(struct device *dev,
3307 struct device_attribute *attr,
3310 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3312 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3316 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3317 * for the parent image. If there is no parent, simply shows
3318 * "(no parent image)".
3320 static ssize_t rbd_parent_show(struct device *dev,
3321 struct device_attribute *attr,
3324 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3325 struct rbd_spec *spec = rbd_dev->parent_spec;
3330 return sprintf(buf, "(no parent image)\n");
3332 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3333 (unsigned long long) spec->pool_id, spec->pool_name);
3338 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3339 spec->image_name ? spec->image_name : "(unknown)");
3344 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3345 (unsigned long long) spec->snap_id, spec->snap_name);
3350 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3355 return (ssize_t) (bufp - buf);
3358 static ssize_t rbd_image_refresh(struct device *dev,
3359 struct device_attribute *attr,
3363 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3366 ret = rbd_dev_refresh(rbd_dev);
3368 rbd_warn(rbd_dev, ": manual header refresh error (%d)\n", ret);
3370 return ret < 0 ? ret : size;
3373 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3374 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3375 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3376 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3377 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3378 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3379 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3380 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3381 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3382 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3383 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3385 static struct attribute *rbd_attrs[] = {
3386 &dev_attr_size.attr,
3387 &dev_attr_features.attr,
3388 &dev_attr_major.attr,
3389 &dev_attr_client_id.attr,
3390 &dev_attr_pool.attr,
3391 &dev_attr_pool_id.attr,
3392 &dev_attr_name.attr,
3393 &dev_attr_image_id.attr,
3394 &dev_attr_current_snap.attr,
3395 &dev_attr_parent.attr,
3396 &dev_attr_refresh.attr,
3400 static struct attribute_group rbd_attr_group = {
3404 static const struct attribute_group *rbd_attr_groups[] = {
3409 static void rbd_sysfs_dev_release(struct device *dev)
3413 static struct device_type rbd_device_type = {
3415 .groups = rbd_attr_groups,
3416 .release = rbd_sysfs_dev_release,
3419 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3421 kref_get(&spec->kref);
3426 static void rbd_spec_free(struct kref *kref);
3427 static void rbd_spec_put(struct rbd_spec *spec)
3430 kref_put(&spec->kref, rbd_spec_free);
3433 static struct rbd_spec *rbd_spec_alloc(void)
3435 struct rbd_spec *spec;
3437 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3440 kref_init(&spec->kref);
3445 static void rbd_spec_free(struct kref *kref)
3447 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3449 kfree(spec->pool_name);
3450 kfree(spec->image_id);
3451 kfree(spec->image_name);
3452 kfree(spec->snap_name);
3456 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3457 struct rbd_spec *spec)
3459 struct rbd_device *rbd_dev;
3461 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3465 spin_lock_init(&rbd_dev->lock);
3467 INIT_LIST_HEAD(&rbd_dev->node);
3468 init_rwsem(&rbd_dev->header_rwsem);
3470 rbd_dev->spec = spec;
3471 rbd_dev->rbd_client = rbdc;
3473 /* Initialize the layout used for all rbd requests */
3475 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3476 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3477 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3478 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3483 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3485 rbd_put_client(rbd_dev->rbd_client);
3486 rbd_spec_put(rbd_dev->spec);
3491 * Get the size and object order for an image snapshot, or if
3492 * snap_id is CEPH_NOSNAP, gets this information for the base
3495 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3496 u8 *order, u64 *snap_size)
3498 __le64 snapid = cpu_to_le64(snap_id);
3503 } __attribute__ ((packed)) size_buf = { 0 };
3505 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3507 &snapid, sizeof (snapid),
3508 &size_buf, sizeof (size_buf));
3509 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3512 if (ret < sizeof (size_buf))
3516 *order = size_buf.order;
3517 *snap_size = le64_to_cpu(size_buf.size);
3519 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3520 (unsigned long long)snap_id, (unsigned int)*order,
3521 (unsigned long long)*snap_size);
3526 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3528 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3529 &rbd_dev->header.obj_order,
3530 &rbd_dev->header.image_size);
3533 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3539 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3543 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3544 "rbd", "get_object_prefix", NULL, 0,
3545 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
3546 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3551 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3552 p + ret, NULL, GFP_NOIO);
3555 if (IS_ERR(rbd_dev->header.object_prefix)) {
3556 ret = PTR_ERR(rbd_dev->header.object_prefix);
3557 rbd_dev->header.object_prefix = NULL;
3559 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3567 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3570 __le64 snapid = cpu_to_le64(snap_id);
3574 } __attribute__ ((packed)) features_buf = { 0 };
3578 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3579 "rbd", "get_features",
3580 &snapid, sizeof (snapid),
3581 &features_buf, sizeof (features_buf));
3582 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3585 if (ret < sizeof (features_buf))
3588 incompat = le64_to_cpu(features_buf.incompat);
3589 if (incompat & ~RBD_FEATURES_SUPPORTED)
3592 *snap_features = le64_to_cpu(features_buf.features);
3594 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3595 (unsigned long long)snap_id,
3596 (unsigned long long)*snap_features,
3597 (unsigned long long)le64_to_cpu(features_buf.incompat));
3602 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3604 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3605 &rbd_dev->header.features);
3608 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3610 struct rbd_spec *parent_spec;
3612 void *reply_buf = NULL;
3620 parent_spec = rbd_spec_alloc();
3624 size = sizeof (__le64) + /* pool_id */
3625 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3626 sizeof (__le64) + /* snap_id */
3627 sizeof (__le64); /* overlap */
3628 reply_buf = kmalloc(size, GFP_KERNEL);
3634 snapid = cpu_to_le64(CEPH_NOSNAP);
3635 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3636 "rbd", "get_parent",
3637 &snapid, sizeof (snapid),
3639 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3644 end = reply_buf + ret;
3646 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
3647 if (parent_spec->pool_id == CEPH_NOPOOL)
3648 goto out; /* No parent? No problem. */
3650 /* The ceph file layout needs to fit pool id in 32 bits */
3653 if (parent_spec->pool_id > (u64)U32_MAX) {
3654 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3655 (unsigned long long)parent_spec->pool_id, U32_MAX);
3659 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3660 if (IS_ERR(image_id)) {
3661 ret = PTR_ERR(image_id);
3664 parent_spec->image_id = image_id;
3665 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3666 ceph_decode_64_safe(&p, end, overlap, out_err);
3669 rbd_dev->parent_spec = parent_spec;
3670 parent_spec = NULL; /* rbd_dev now owns this */
3671 rbd_dev->parent_overlap = overlap;
3673 rbd_warn(rbd_dev, "ignoring parent of clone with overlap 0\n");
3679 rbd_spec_put(parent_spec);
3684 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3688 __le64 stripe_count;
3689 } __attribute__ ((packed)) striping_info_buf = { 0 };
3690 size_t size = sizeof (striping_info_buf);
3697 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3698 "rbd", "get_stripe_unit_count", NULL, 0,
3699 (char *)&striping_info_buf, size);
3700 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3707 * We don't actually support the "fancy striping" feature
3708 * (STRIPINGV2) yet, but if the striping sizes are the
3709 * defaults the behavior is the same as before. So find
3710 * out, and only fail if the image has non-default values.
3713 obj_size = (u64)1 << rbd_dev->header.obj_order;
3714 p = &striping_info_buf;
3715 stripe_unit = ceph_decode_64(&p);
3716 if (stripe_unit != obj_size) {
3717 rbd_warn(rbd_dev, "unsupported stripe unit "
3718 "(got %llu want %llu)",
3719 stripe_unit, obj_size);
3722 stripe_count = ceph_decode_64(&p);
3723 if (stripe_count != 1) {
3724 rbd_warn(rbd_dev, "unsupported stripe count "
3725 "(got %llu want 1)", stripe_count);
3728 rbd_dev->header.stripe_unit = stripe_unit;
3729 rbd_dev->header.stripe_count = stripe_count;
3734 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3736 size_t image_id_size;
3741 void *reply_buf = NULL;
3743 char *image_name = NULL;
3746 rbd_assert(!rbd_dev->spec->image_name);
3748 len = strlen(rbd_dev->spec->image_id);
3749 image_id_size = sizeof (__le32) + len;
3750 image_id = kmalloc(image_id_size, GFP_KERNEL);
3755 end = image_id + image_id_size;
3756 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3758 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3759 reply_buf = kmalloc(size, GFP_KERNEL);
3763 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3764 "rbd", "dir_get_name",
3765 image_id, image_id_size,
3770 end = reply_buf + ret;
3772 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3773 if (IS_ERR(image_name))
3776 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3784 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3786 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3787 const char *snap_name;
3790 /* Skip over names until we find the one we are looking for */
3792 snap_name = rbd_dev->header.snap_names;
3793 while (which < snapc->num_snaps) {
3794 if (!strcmp(name, snap_name))
3795 return snapc->snaps[which];
3796 snap_name += strlen(snap_name) + 1;
3802 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3804 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3809 for (which = 0; !found && which < snapc->num_snaps; which++) {
3810 const char *snap_name;
3812 snap_id = snapc->snaps[which];
3813 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
3814 if (IS_ERR(snap_name))
3816 found = !strcmp(name, snap_name);
3819 return found ? snap_id : CEPH_NOSNAP;
3823 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
3824 * no snapshot by that name is found, or if an error occurs.
3826 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3828 if (rbd_dev->image_format == 1)
3829 return rbd_v1_snap_id_by_name(rbd_dev, name);
3831 return rbd_v2_snap_id_by_name(rbd_dev, name);
3835 * When an rbd image has a parent image, it is identified by the
3836 * pool, image, and snapshot ids (not names). This function fills
3837 * in the names for those ids. (It's OK if we can't figure out the
3838 * name for an image id, but the pool and snapshot ids should always
3839 * exist and have names.) All names in an rbd spec are dynamically
3842 * When an image being mapped (not a parent) is probed, we have the
3843 * pool name and pool id, image name and image id, and the snapshot
3844 * name. The only thing we're missing is the snapshot id.
3846 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
3848 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3849 struct rbd_spec *spec = rbd_dev->spec;
3850 const char *pool_name;
3851 const char *image_name;
3852 const char *snap_name;
3856 * An image being mapped will have the pool name (etc.), but
3857 * we need to look up the snapshot id.
3859 if (spec->pool_name) {
3860 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
3863 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
3864 if (snap_id == CEPH_NOSNAP)
3866 spec->snap_id = snap_id;
3868 spec->snap_id = CEPH_NOSNAP;
3874 /* Get the pool name; we have to make our own copy of this */
3876 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
3878 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
3881 pool_name = kstrdup(pool_name, GFP_KERNEL);
3885 /* Fetch the image name; tolerate failure here */
3887 image_name = rbd_dev_image_name(rbd_dev);
3889 rbd_warn(rbd_dev, "unable to get image name");
3891 /* Look up the snapshot name, and make a copy */
3893 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
3899 spec->pool_name = pool_name;
3900 spec->image_name = image_name;
3901 spec->snap_name = snap_name;
3911 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
3920 struct ceph_snap_context *snapc;
3924 * We'll need room for the seq value (maximum snapshot id),
3925 * snapshot count, and array of that many snapshot ids.
3926 * For now we have a fixed upper limit on the number we're
3927 * prepared to receive.
3929 size = sizeof (__le64) + sizeof (__le32) +
3930 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3931 reply_buf = kzalloc(size, GFP_KERNEL);
3935 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3936 "rbd", "get_snapcontext", NULL, 0,
3938 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3943 end = reply_buf + ret;
3945 ceph_decode_64_safe(&p, end, seq, out);
3946 ceph_decode_32_safe(&p, end, snap_count, out);
3949 * Make sure the reported number of snapshot ids wouldn't go
3950 * beyond the end of our buffer. But before checking that,
3951 * make sure the computed size of the snapshot context we
3952 * allocate is representable in a size_t.
3954 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
3959 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
3963 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
3969 for (i = 0; i < snap_count; i++)
3970 snapc->snaps[i] = ceph_decode_64(&p);
3972 ceph_put_snap_context(rbd_dev->header.snapc);
3973 rbd_dev->header.snapc = snapc;
3975 dout(" snap context seq = %llu, snap_count = %u\n",
3976 (unsigned long long)seq, (unsigned int)snap_count);
3983 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
3994 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
3995 reply_buf = kmalloc(size, GFP_KERNEL);
3997 return ERR_PTR(-ENOMEM);
3999 snapid = cpu_to_le64(snap_id);
4000 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4001 "rbd", "get_snapshot_name",
4002 &snapid, sizeof (snapid),
4004 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4006 snap_name = ERR_PTR(ret);
4011 end = reply_buf + ret;
4012 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4013 if (IS_ERR(snap_name))
4016 dout(" snap_id 0x%016llx snap_name = %s\n",
4017 (unsigned long long)snap_id, snap_name);
4024 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
4026 bool first_time = rbd_dev->header.object_prefix == NULL;
4029 down_write(&rbd_dev->header_rwsem);
4032 ret = rbd_dev_v2_header_onetime(rbd_dev);
4037 ret = rbd_dev_v2_image_size(rbd_dev);
4040 if (rbd_dev->spec->snap_id == CEPH_NOSNAP)
4041 if (rbd_dev->mapping.size != rbd_dev->header.image_size)
4042 rbd_dev->mapping.size = rbd_dev->header.image_size;
4044 ret = rbd_dev_v2_snap_context(rbd_dev);
4045 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4049 up_write(&rbd_dev->header_rwsem);
4054 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4059 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4061 dev = &rbd_dev->dev;
4062 dev->bus = &rbd_bus_type;
4063 dev->type = &rbd_device_type;
4064 dev->parent = &rbd_root_dev;
4065 dev->release = rbd_dev_device_release;
4066 dev_set_name(dev, "%d", rbd_dev->dev_id);
4067 ret = device_register(dev);
4069 mutex_unlock(&ctl_mutex);
4074 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4076 device_unregister(&rbd_dev->dev);
4079 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4082 * Get a unique rbd identifier for the given new rbd_dev, and add
4083 * the rbd_dev to the global list. The minimum rbd id is 1.
4085 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4087 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4089 spin_lock(&rbd_dev_list_lock);
4090 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4091 spin_unlock(&rbd_dev_list_lock);
4092 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4093 (unsigned long long) rbd_dev->dev_id);
4097 * Remove an rbd_dev from the global list, and record that its
4098 * identifier is no longer in use.
4100 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4102 struct list_head *tmp;
4103 int rbd_id = rbd_dev->dev_id;
4106 rbd_assert(rbd_id > 0);
4108 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4109 (unsigned long long) rbd_dev->dev_id);
4110 spin_lock(&rbd_dev_list_lock);
4111 list_del_init(&rbd_dev->node);
4114 * If the id being "put" is not the current maximum, there
4115 * is nothing special we need to do.
4117 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4118 spin_unlock(&rbd_dev_list_lock);
4123 * We need to update the current maximum id. Search the
4124 * list to find out what it is. We're more likely to find
4125 * the maximum at the end, so search the list backward.
4128 list_for_each_prev(tmp, &rbd_dev_list) {
4129 struct rbd_device *rbd_dev;
4131 rbd_dev = list_entry(tmp, struct rbd_device, node);
4132 if (rbd_dev->dev_id > max_id)
4133 max_id = rbd_dev->dev_id;
4135 spin_unlock(&rbd_dev_list_lock);
4138 * The max id could have been updated by rbd_dev_id_get(), in
4139 * which case it now accurately reflects the new maximum.
4140 * Be careful not to overwrite the maximum value in that
4143 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4144 dout(" max dev id has been reset\n");
4148 * Skips over white space at *buf, and updates *buf to point to the
4149 * first found non-space character (if any). Returns the length of
4150 * the token (string of non-white space characters) found. Note
4151 * that *buf must be terminated with '\0'.
4153 static inline size_t next_token(const char **buf)
4156 * These are the characters that produce nonzero for
4157 * isspace() in the "C" and "POSIX" locales.
4159 const char *spaces = " \f\n\r\t\v";
4161 *buf += strspn(*buf, spaces); /* Find start of token */
4163 return strcspn(*buf, spaces); /* Return token length */
4167 * Finds the next token in *buf, and if the provided token buffer is
4168 * big enough, copies the found token into it. The result, if
4169 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4170 * must be terminated with '\0' on entry.
4172 * Returns the length of the token found (not including the '\0').
4173 * Return value will be 0 if no token is found, and it will be >=
4174 * token_size if the token would not fit.
4176 * The *buf pointer will be updated to point beyond the end of the
4177 * found token. Note that this occurs even if the token buffer is
4178 * too small to hold it.
4180 static inline size_t copy_token(const char **buf,
4186 len = next_token(buf);
4187 if (len < token_size) {
4188 memcpy(token, *buf, len);
4189 *(token + len) = '\0';
4197 * Finds the next token in *buf, dynamically allocates a buffer big
4198 * enough to hold a copy of it, and copies the token into the new
4199 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4200 * that a duplicate buffer is created even for a zero-length token.
4202 * Returns a pointer to the newly-allocated duplicate, or a null
4203 * pointer if memory for the duplicate was not available. If
4204 * the lenp argument is a non-null pointer, the length of the token
4205 * (not including the '\0') is returned in *lenp.
4207 * If successful, the *buf pointer will be updated to point beyond
4208 * the end of the found token.
4210 * Note: uses GFP_KERNEL for allocation.
4212 static inline char *dup_token(const char **buf, size_t *lenp)
4217 len = next_token(buf);
4218 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4221 *(dup + len) = '\0';
4231 * Parse the options provided for an "rbd add" (i.e., rbd image
4232 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4233 * and the data written is passed here via a NUL-terminated buffer.
4234 * Returns 0 if successful or an error code otherwise.
4236 * The information extracted from these options is recorded in
4237 * the other parameters which return dynamically-allocated
4240 * The address of a pointer that will refer to a ceph options
4241 * structure. Caller must release the returned pointer using
4242 * ceph_destroy_options() when it is no longer needed.
4244 * Address of an rbd options pointer. Fully initialized by
4245 * this function; caller must release with kfree().
4247 * Address of an rbd image specification pointer. Fully
4248 * initialized by this function based on parsed options.
4249 * Caller must release with rbd_spec_put().
4251 * The options passed take this form:
4252 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4255 * A comma-separated list of one or more monitor addresses.
4256 * A monitor address is an ip address, optionally followed
4257 * by a port number (separated by a colon).
4258 * I.e.: ip1[:port1][,ip2[:port2]...]
4260 * A comma-separated list of ceph and/or rbd options.
4262 * The name of the rados pool containing the rbd image.
4264 * The name of the image in that pool to map.
4266 * An optional snapshot id. If provided, the mapping will
4267 * present data from the image at the time that snapshot was
4268 * created. The image head is used if no snapshot id is
4269 * provided. Snapshot mappings are always read-only.
4271 static int rbd_add_parse_args(const char *buf,
4272 struct ceph_options **ceph_opts,
4273 struct rbd_options **opts,
4274 struct rbd_spec **rbd_spec)
4278 const char *mon_addrs;
4280 size_t mon_addrs_size;
4281 struct rbd_spec *spec = NULL;
4282 struct rbd_options *rbd_opts = NULL;
4283 struct ceph_options *copts;
4286 /* The first four tokens are required */
4288 len = next_token(&buf);
4290 rbd_warn(NULL, "no monitor address(es) provided");
4294 mon_addrs_size = len + 1;
4298 options = dup_token(&buf, NULL);
4302 rbd_warn(NULL, "no options provided");
4306 spec = rbd_spec_alloc();
4310 spec->pool_name = dup_token(&buf, NULL);
4311 if (!spec->pool_name)
4313 if (!*spec->pool_name) {
4314 rbd_warn(NULL, "no pool name provided");
4318 spec->image_name = dup_token(&buf, NULL);
4319 if (!spec->image_name)
4321 if (!*spec->image_name) {
4322 rbd_warn(NULL, "no image name provided");
4327 * Snapshot name is optional; default is to use "-"
4328 * (indicating the head/no snapshot).
4330 len = next_token(&buf);
4332 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4333 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4334 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4335 ret = -ENAMETOOLONG;
4338 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4341 *(snap_name + len) = '\0';
4342 spec->snap_name = snap_name;
4344 /* Initialize all rbd options to the defaults */
4346 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4350 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4352 copts = ceph_parse_options(options, mon_addrs,
4353 mon_addrs + mon_addrs_size - 1,
4354 parse_rbd_opts_token, rbd_opts);
4355 if (IS_ERR(copts)) {
4356 ret = PTR_ERR(copts);
4377 * An rbd format 2 image has a unique identifier, distinct from the
4378 * name given to it by the user. Internally, that identifier is
4379 * what's used to specify the names of objects related to the image.
4381 * A special "rbd id" object is used to map an rbd image name to its
4382 * id. If that object doesn't exist, then there is no v2 rbd image
4383 * with the supplied name.
4385 * This function will record the given rbd_dev's image_id field if
4386 * it can be determined, and in that case will return 0. If any
4387 * errors occur a negative errno will be returned and the rbd_dev's
4388 * image_id field will be unchanged (and should be NULL).
4390 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4399 * When probing a parent image, the image id is already
4400 * known (and the image name likely is not). There's no
4401 * need to fetch the image id again in this case. We
4402 * do still need to set the image format though.
4404 if (rbd_dev->spec->image_id) {
4405 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4411 * First, see if the format 2 image id file exists, and if
4412 * so, get the image's persistent id from it.
4414 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4415 object_name = kmalloc(size, GFP_NOIO);
4418 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4419 dout("rbd id object name is %s\n", object_name);
4421 /* Response will be an encoded string, which includes a length */
4423 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4424 response = kzalloc(size, GFP_NOIO);
4430 /* If it doesn't exist we'll assume it's a format 1 image */
4432 ret = rbd_obj_method_sync(rbd_dev, object_name,
4433 "rbd", "get_id", NULL, 0,
4434 response, RBD_IMAGE_ID_LEN_MAX);
4435 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4436 if (ret == -ENOENT) {
4437 image_id = kstrdup("", GFP_KERNEL);
4438 ret = image_id ? 0 : -ENOMEM;
4440 rbd_dev->image_format = 1;
4441 } else if (ret > sizeof (__le32)) {
4444 image_id = ceph_extract_encoded_string(&p, p + ret,
4446 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4448 rbd_dev->image_format = 2;
4454 rbd_dev->spec->image_id = image_id;
4455 dout("image_id is %s\n", image_id);
4464 /* Undo whatever state changes are made by v1 or v2 image probe */
4466 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
4468 struct rbd_image_header *header;
4470 rbd_dev_remove_parent(rbd_dev);
4471 rbd_spec_put(rbd_dev->parent_spec);
4472 rbd_dev->parent_spec = NULL;
4473 rbd_dev->parent_overlap = 0;
4475 /* Free dynamic fields from the header, then zero it out */
4477 header = &rbd_dev->header;
4478 ceph_put_snap_context(header->snapc);
4479 kfree(header->snap_sizes);
4480 kfree(header->snap_names);
4481 kfree(header->object_prefix);
4482 memset(header, 0, sizeof (*header));
4485 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
4489 ret = rbd_dev_v2_object_prefix(rbd_dev);
4494 * Get the and check features for the image. Currently the
4495 * features are assumed to never change.
4497 ret = rbd_dev_v2_features(rbd_dev);
4501 /* If the image supports layering, get the parent info */
4503 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
4504 ret = rbd_dev_v2_parent_info(rbd_dev);
4508 * Print a warning if this image has a parent.
4509 * Don't print it if the image now being probed
4510 * is itself a parent. We can tell at this point
4511 * because we won't know its pool name yet (just its
4514 if (rbd_dev->parent_spec && rbd_dev->spec->pool_name)
4515 rbd_warn(rbd_dev, "WARNING: kernel layering "
4516 "is EXPERIMENTAL!");
4519 /* If the image supports fancy striping, get its parameters */
4521 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4522 ret = rbd_dev_v2_striping_info(rbd_dev);
4526 /* No support for crypto and compression type format 2 images */
4530 rbd_dev->parent_overlap = 0;
4531 rbd_spec_put(rbd_dev->parent_spec);
4532 rbd_dev->parent_spec = NULL;
4533 kfree(rbd_dev->header_name);
4534 rbd_dev->header_name = NULL;
4535 kfree(rbd_dev->header.object_prefix);
4536 rbd_dev->header.object_prefix = NULL;
4541 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4543 struct rbd_device *parent = NULL;
4544 struct rbd_spec *parent_spec;
4545 struct rbd_client *rbdc;
4548 if (!rbd_dev->parent_spec)
4551 * We need to pass a reference to the client and the parent
4552 * spec when creating the parent rbd_dev. Images related by
4553 * parent/child relationships always share both.
4555 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4556 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4559 parent = rbd_dev_create(rbdc, parent_spec);
4563 ret = rbd_dev_image_probe(parent, false);
4566 rbd_dev->parent = parent;
4571 rbd_spec_put(rbd_dev->parent_spec);
4572 kfree(rbd_dev->header_name);
4573 rbd_dev_destroy(parent);
4575 rbd_put_client(rbdc);
4576 rbd_spec_put(parent_spec);
4582 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
4586 /* generate unique id: find highest unique id, add one */
4587 rbd_dev_id_get(rbd_dev);
4589 /* Fill in the device name, now that we have its id. */
4590 BUILD_BUG_ON(DEV_NAME_LEN
4591 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4592 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4594 /* Get our block major device number. */
4596 ret = register_blkdev(0, rbd_dev->name);
4599 rbd_dev->major = ret;
4601 /* Set up the blkdev mapping. */
4603 ret = rbd_init_disk(rbd_dev);
4605 goto err_out_blkdev;
4607 ret = rbd_dev_mapping_set(rbd_dev);
4610 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4612 ret = rbd_bus_add_dev(rbd_dev);
4614 goto err_out_mapping;
4616 /* Everything's ready. Announce the disk to the world. */
4618 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4619 add_disk(rbd_dev->disk);
4621 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4622 (unsigned long long) rbd_dev->mapping.size);
4627 rbd_dev_mapping_clear(rbd_dev);
4629 rbd_free_disk(rbd_dev);
4631 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4633 rbd_dev_id_put(rbd_dev);
4634 rbd_dev_mapping_clear(rbd_dev);
4639 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
4641 struct rbd_spec *spec = rbd_dev->spec;
4644 /* Record the header object name for this rbd image. */
4646 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4648 if (rbd_dev->image_format == 1)
4649 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
4651 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
4653 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4654 if (!rbd_dev->header_name)
4657 if (rbd_dev->image_format == 1)
4658 sprintf(rbd_dev->header_name, "%s%s",
4659 spec->image_name, RBD_SUFFIX);
4661 sprintf(rbd_dev->header_name, "%s%s",
4662 RBD_HEADER_PREFIX, spec->image_id);
4666 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
4668 rbd_dev_unprobe(rbd_dev);
4669 kfree(rbd_dev->header_name);
4670 rbd_dev->header_name = NULL;
4671 rbd_dev->image_format = 0;
4672 kfree(rbd_dev->spec->image_id);
4673 rbd_dev->spec->image_id = NULL;
4675 rbd_dev_destroy(rbd_dev);
4679 * Probe for the existence of the header object for the given rbd
4680 * device. If this image is the one being mapped (i.e., not a
4681 * parent), initiate a watch on its header object before using that
4682 * object to get detailed information about the rbd image.
4684 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping)
4690 * Get the id from the image id object. If it's not a
4691 * format 2 image, we'll get ENOENT back, and we'll assume
4692 * it's a format 1 image.
4694 ret = rbd_dev_image_id(rbd_dev);
4697 rbd_assert(rbd_dev->spec->image_id);
4698 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4700 ret = rbd_dev_header_name(rbd_dev);
4702 goto err_out_format;
4705 ret = rbd_dev_header_watch_sync(rbd_dev, true);
4707 goto out_header_name;
4710 if (rbd_dev->image_format == 1)
4711 ret = rbd_dev_v1_header_info(rbd_dev);
4713 ret = rbd_dev_v2_header_info(rbd_dev);
4717 ret = rbd_dev_spec_update(rbd_dev);
4721 ret = rbd_dev_probe_parent(rbd_dev);
4725 dout("discovered format %u image, header name is %s\n",
4726 rbd_dev->image_format, rbd_dev->header_name);
4730 rbd_dev_unprobe(rbd_dev);
4733 tmp = rbd_dev_header_watch_sync(rbd_dev, false);
4735 rbd_warn(rbd_dev, "unable to tear down "
4736 "watch request (%d)\n", tmp);
4739 kfree(rbd_dev->header_name);
4740 rbd_dev->header_name = NULL;
4742 rbd_dev->image_format = 0;
4743 kfree(rbd_dev->spec->image_id);
4744 rbd_dev->spec->image_id = NULL;
4746 dout("probe failed, returning %d\n", ret);
4751 static ssize_t rbd_add(struct bus_type *bus,
4755 struct rbd_device *rbd_dev = NULL;
4756 struct ceph_options *ceph_opts = NULL;
4757 struct rbd_options *rbd_opts = NULL;
4758 struct rbd_spec *spec = NULL;
4759 struct rbd_client *rbdc;
4760 struct ceph_osd_client *osdc;
4764 if (!try_module_get(THIS_MODULE))
4767 /* parse add command */
4768 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4770 goto err_out_module;
4771 read_only = rbd_opts->read_only;
4773 rbd_opts = NULL; /* done with this */
4775 rbdc = rbd_get_client(ceph_opts);
4780 ceph_opts = NULL; /* rbd_dev client now owns this */
4783 osdc = &rbdc->client->osdc;
4784 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4786 goto err_out_client;
4787 spec->pool_id = (u64)rc;
4789 /* The ceph file layout needs to fit pool id in 32 bits */
4791 if (spec->pool_id > (u64)U32_MAX) {
4792 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4793 (unsigned long long)spec->pool_id, U32_MAX);
4795 goto err_out_client;
4798 rbd_dev = rbd_dev_create(rbdc, spec);
4800 goto err_out_client;
4801 rbdc = NULL; /* rbd_dev now owns this */
4802 spec = NULL; /* rbd_dev now owns this */
4804 rc = rbd_dev_image_probe(rbd_dev, true);
4806 goto err_out_rbd_dev;
4808 /* If we are mapping a snapshot it must be marked read-only */
4810 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
4812 rbd_dev->mapping.read_only = read_only;
4814 rc = rbd_dev_device_setup(rbd_dev);
4818 rbd_dev_image_release(rbd_dev);
4820 rbd_dev_destroy(rbd_dev);
4822 rbd_put_client(rbdc);
4825 ceph_destroy_options(ceph_opts);
4829 module_put(THIS_MODULE);
4831 dout("Error adding device %s\n", buf);
4836 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4838 struct list_head *tmp;
4839 struct rbd_device *rbd_dev;
4841 spin_lock(&rbd_dev_list_lock);
4842 list_for_each(tmp, &rbd_dev_list) {
4843 rbd_dev = list_entry(tmp, struct rbd_device, node);
4844 if (rbd_dev->dev_id == dev_id) {
4845 spin_unlock(&rbd_dev_list_lock);
4849 spin_unlock(&rbd_dev_list_lock);
4853 static void rbd_dev_device_release(struct device *dev)
4855 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4857 rbd_free_disk(rbd_dev);
4858 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4859 rbd_dev_mapping_clear(rbd_dev);
4860 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4862 rbd_dev_id_put(rbd_dev);
4863 rbd_dev_mapping_clear(rbd_dev);
4866 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
4868 while (rbd_dev->parent) {
4869 struct rbd_device *first = rbd_dev;
4870 struct rbd_device *second = first->parent;
4871 struct rbd_device *third;
4874 * Follow to the parent with no grandparent and
4877 while (second && (third = second->parent)) {
4882 rbd_dev_image_release(second);
4883 first->parent = NULL;
4884 first->parent_overlap = 0;
4886 rbd_assert(first->parent_spec);
4887 rbd_spec_put(first->parent_spec);
4888 first->parent_spec = NULL;
4892 static ssize_t rbd_remove(struct bus_type *bus,
4896 struct rbd_device *rbd_dev = NULL;
4901 ret = strict_strtoul(buf, 10, &ul);
4905 /* convert to int; abort if we lost anything in the conversion */
4906 target_id = (int) ul;
4907 if (target_id != ul)
4910 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4912 rbd_dev = __rbd_get_dev(target_id);
4918 spin_lock_irq(&rbd_dev->lock);
4919 if (rbd_dev->open_count)
4922 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
4923 spin_unlock_irq(&rbd_dev->lock);
4926 rbd_bus_del_dev(rbd_dev);
4927 ret = rbd_dev_header_watch_sync(rbd_dev, false);
4929 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
4930 rbd_dev_image_release(rbd_dev);
4931 module_put(THIS_MODULE);
4934 mutex_unlock(&ctl_mutex);
4940 * create control files in sysfs
4943 static int rbd_sysfs_init(void)
4947 ret = device_register(&rbd_root_dev);
4951 ret = bus_register(&rbd_bus_type);
4953 device_unregister(&rbd_root_dev);
4958 static void rbd_sysfs_cleanup(void)
4960 bus_unregister(&rbd_bus_type);
4961 device_unregister(&rbd_root_dev);
4964 static int rbd_slab_init(void)
4966 rbd_assert(!rbd_img_request_cache);
4967 rbd_img_request_cache = kmem_cache_create("rbd_img_request",
4968 sizeof (struct rbd_img_request),
4969 __alignof__(struct rbd_img_request),
4971 if (!rbd_img_request_cache)
4974 rbd_assert(!rbd_obj_request_cache);
4975 rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
4976 sizeof (struct rbd_obj_request),
4977 __alignof__(struct rbd_obj_request),
4979 if (!rbd_obj_request_cache)
4982 rbd_assert(!rbd_segment_name_cache);
4983 rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
4984 MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL);
4985 if (rbd_segment_name_cache)
4988 if (rbd_obj_request_cache) {
4989 kmem_cache_destroy(rbd_obj_request_cache);
4990 rbd_obj_request_cache = NULL;
4993 kmem_cache_destroy(rbd_img_request_cache);
4994 rbd_img_request_cache = NULL;
4999 static void rbd_slab_exit(void)
5001 rbd_assert(rbd_segment_name_cache);
5002 kmem_cache_destroy(rbd_segment_name_cache);
5003 rbd_segment_name_cache = NULL;
5005 rbd_assert(rbd_obj_request_cache);
5006 kmem_cache_destroy(rbd_obj_request_cache);
5007 rbd_obj_request_cache = NULL;
5009 rbd_assert(rbd_img_request_cache);
5010 kmem_cache_destroy(rbd_img_request_cache);
5011 rbd_img_request_cache = NULL;
5014 static int __init rbd_init(void)
5018 if (!libceph_compatible(NULL)) {
5019 rbd_warn(NULL, "libceph incompatibility (quitting)");
5023 rc = rbd_slab_init();
5026 rc = rbd_sysfs_init();
5030 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5035 static void __exit rbd_exit(void)
5037 rbd_sysfs_cleanup();
5041 module_init(rbd_init);
5042 module_exit(rbd_exit);
5044 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5045 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5046 MODULE_DESCRIPTION("rados block device");
5048 /* following authorship retained from original osdblk.c */
5049 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5051 MODULE_LICENSE("GPL");