2 rbd.c -- Export ceph rados objects as a Linux block device
5 based on drivers/block/osdblk.c:
7 Copyright 2009 Red Hat, Inc.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; see the file COPYING. If not, write to
20 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
24 For usage instructions, please refer to:
26 Documentation/ABI/testing/sysfs-bus-rbd
30 #include <linux/ceph/libceph.h>
31 #include <linux/ceph/osd_client.h>
32 #include <linux/ceph/mon_client.h>
33 #include <linux/ceph/decode.h>
34 #include <linux/parser.h>
36 #include <linux/kernel.h>
37 #include <linux/device.h>
38 #include <linux/module.h>
40 #include <linux/blkdev.h>
42 #include "rbd_types.h"
44 #define RBD_DEBUG /* Activate rbd_assert() calls */
47 * The basic unit of block I/O is a sector. It is interpreted in a
48 * number of contexts in Linux (blk, bio, genhd), but the default is
49 * universally 512 bytes. These symbols are just slightly more
50 * meaningful than the bare numbers they represent.
52 #define SECTOR_SHIFT 9
53 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT)
55 #define RBD_DRV_NAME "rbd"
56 #define RBD_DRV_NAME_LONG "rbd (rados block device)"
58 #define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
60 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
61 #define RBD_MAX_SNAP_NAME_LEN \
62 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
64 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
66 #define RBD_SNAP_HEAD_NAME "-"
68 /* This allows a single page to hold an image name sent by OSD */
69 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
70 #define RBD_IMAGE_ID_LEN_MAX 64
72 #define RBD_OBJ_PREFIX_LEN_MAX 64
76 #define RBD_FEATURE_LAYERING 1
78 /* Features supported by this (client software) implementation. */
80 #define RBD_FEATURES_ALL (0)
83 * An RBD device name will be "rbd#", where the "rbd" comes from
84 * RBD_DRV_NAME above, and # is a unique integer identifier.
85 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
86 * enough to hold all possible device names.
88 #define DEV_NAME_LEN 32
89 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
92 * block device image metadata (in-memory version)
94 struct rbd_image_header {
95 /* These four fields never change for a given rbd image */
102 /* The remaining fields need to be updated occasionally */
104 struct ceph_snap_context *snapc;
112 * An rbd image specification.
114 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
115 * identify an image. Each rbd_dev structure includes a pointer to
116 * an rbd_spec structure that encapsulates this identity.
118 * Each of the id's in an rbd_spec has an associated name. For a
119 * user-mapped image, the names are supplied and the id's associated
120 * with them are looked up. For a layered image, a parent image is
121 * defined by the tuple, and the names are looked up.
123 * An rbd_dev structure contains a parent_spec pointer which is
124 * non-null if the image it represents is a child in a layered
125 * image. This pointer will refer to the rbd_spec structure used
126 * by the parent rbd_dev for its own identity (i.e., the structure
127 * is shared between the parent and child).
129 * Since these structures are populated once, during the discovery
130 * phase of image construction, they are effectively immutable so
131 * we make no effort to synchronize access to them.
133 * Note that code herein does not assume the image name is known (it
134 * could be a null pointer).
150 * an instance of the client. multiple devices may share an rbd client.
153 struct ceph_client *client;
155 struct list_head node;
158 struct rbd_img_request;
159 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
161 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
163 struct rbd_obj_request;
164 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
166 enum obj_request_type {
167 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
170 struct rbd_obj_request {
171 const char *object_name;
172 u64 offset; /* object start byte */
173 u64 length; /* bytes from offset */
175 struct rbd_img_request *img_request;
176 struct list_head links; /* img_request->obj_requests */
177 u32 which; /* posn image request list */
179 enum obj_request_type type;
181 struct bio *bio_list;
188 struct ceph_osd_request *osd_req;
190 u64 xferred; /* bytes transferred */
195 rbd_obj_callback_t callback;
196 struct completion completion;
201 struct rbd_img_request {
203 struct rbd_device *rbd_dev;
204 u64 offset; /* starting image byte offset */
205 u64 length; /* byte count from offset */
206 bool write_request; /* false for read */
208 struct ceph_snap_context *snapc; /* for writes */
209 u64 snap_id; /* for reads */
211 spinlock_t completion_lock;/* protects next_completion */
213 rbd_img_callback_t callback;
215 u32 obj_request_count;
216 struct list_head obj_requests; /* rbd_obj_request structs */
221 #define for_each_obj_request(ireq, oreq) \
222 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
223 #define for_each_obj_request_from(ireq, oreq) \
224 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
225 #define for_each_obj_request_safe(ireq, oreq, n) \
226 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
232 struct list_head node;
247 int dev_id; /* blkdev unique id */
249 int major; /* blkdev assigned major */
250 struct gendisk *disk; /* blkdev's gendisk and rq */
252 u32 image_format; /* Either 1 or 2 */
253 struct rbd_client *rbd_client;
255 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
257 spinlock_t lock; /* queue, flags, open_count */
259 struct rbd_image_header header;
260 unsigned long flags; /* possibly lock protected */
261 struct rbd_spec *spec;
265 struct ceph_file_layout layout;
267 struct ceph_osd_event *watch_event;
268 struct rbd_obj_request *watch_request;
270 struct rbd_spec *parent_spec;
273 /* protects updating the header */
274 struct rw_semaphore header_rwsem;
276 struct rbd_mapping mapping;
278 struct list_head node;
280 /* list of snapshots */
281 struct list_head snaps;
285 unsigned long open_count; /* protected by lock */
289 * Flag bits for rbd_dev->flags. If atomicity is required,
290 * rbd_dev->lock is used to protect access.
292 * Currently, only the "removing" flag (which is coupled with the
293 * "open_count" field) requires atomic access.
296 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
297 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
300 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
302 static LIST_HEAD(rbd_dev_list); /* devices */
303 static DEFINE_SPINLOCK(rbd_dev_list_lock);
305 static LIST_HEAD(rbd_client_list); /* clients */
306 static DEFINE_SPINLOCK(rbd_client_list_lock);
308 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev);
309 static int rbd_dev_snaps_register(struct rbd_device *rbd_dev);
311 static void rbd_dev_release(struct device *dev);
312 static void rbd_remove_snap_dev(struct rbd_snap *snap);
314 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
316 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
319 static struct bus_attribute rbd_bus_attrs[] = {
320 __ATTR(add, S_IWUSR, NULL, rbd_add),
321 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
325 static struct bus_type rbd_bus_type = {
327 .bus_attrs = rbd_bus_attrs,
330 static void rbd_root_dev_release(struct device *dev)
334 static struct device rbd_root_dev = {
336 .release = rbd_root_dev_release,
339 static __printf(2, 3)
340 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
342 struct va_format vaf;
350 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
351 else if (rbd_dev->disk)
352 printk(KERN_WARNING "%s: %s: %pV\n",
353 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
354 else if (rbd_dev->spec && rbd_dev->spec->image_name)
355 printk(KERN_WARNING "%s: image %s: %pV\n",
356 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
357 else if (rbd_dev->spec && rbd_dev->spec->image_id)
358 printk(KERN_WARNING "%s: id %s: %pV\n",
359 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
361 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
362 RBD_DRV_NAME, rbd_dev, &vaf);
367 #define rbd_assert(expr) \
368 if (unlikely(!(expr))) { \
369 printk(KERN_ERR "\nAssertion failure in %s() " \
371 "\trbd_assert(%s);\n\n", \
372 __func__, __LINE__, #expr); \
375 #else /* !RBD_DEBUG */
376 # define rbd_assert(expr) ((void) 0)
377 #endif /* !RBD_DEBUG */
379 static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver);
380 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver);
382 static int rbd_open(struct block_device *bdev, fmode_t mode)
384 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
385 bool removing = false;
387 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
390 spin_lock_irq(&rbd_dev->lock);
391 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
394 rbd_dev->open_count++;
395 spin_unlock_irq(&rbd_dev->lock);
399 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
400 (void) get_device(&rbd_dev->dev);
401 set_device_ro(bdev, rbd_dev->mapping.read_only);
402 mutex_unlock(&ctl_mutex);
407 static int rbd_release(struct gendisk *disk, fmode_t mode)
409 struct rbd_device *rbd_dev = disk->private_data;
410 unsigned long open_count_before;
412 spin_lock_irq(&rbd_dev->lock);
413 open_count_before = rbd_dev->open_count--;
414 spin_unlock_irq(&rbd_dev->lock);
415 rbd_assert(open_count_before > 0);
417 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
418 put_device(&rbd_dev->dev);
419 mutex_unlock(&ctl_mutex);
424 static const struct block_device_operations rbd_bd_ops = {
425 .owner = THIS_MODULE,
427 .release = rbd_release,
431 * Initialize an rbd client instance.
434 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
436 struct rbd_client *rbdc;
439 dout("%s:\n", __func__);
440 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
444 kref_init(&rbdc->kref);
445 INIT_LIST_HEAD(&rbdc->node);
447 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
449 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
450 if (IS_ERR(rbdc->client))
452 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
454 ret = ceph_open_session(rbdc->client);
458 spin_lock(&rbd_client_list_lock);
459 list_add_tail(&rbdc->node, &rbd_client_list);
460 spin_unlock(&rbd_client_list_lock);
462 mutex_unlock(&ctl_mutex);
463 dout("%s: rbdc %p\n", __func__, rbdc);
468 ceph_destroy_client(rbdc->client);
470 mutex_unlock(&ctl_mutex);
474 ceph_destroy_options(ceph_opts);
475 dout("%s: error %d\n", __func__, ret);
481 * Find a ceph client with specific addr and configuration. If
482 * found, bump its reference count.
484 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
486 struct rbd_client *client_node;
489 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
492 spin_lock(&rbd_client_list_lock);
493 list_for_each_entry(client_node, &rbd_client_list, node) {
494 if (!ceph_compare_options(ceph_opts, client_node->client)) {
495 kref_get(&client_node->kref);
500 spin_unlock(&rbd_client_list_lock);
502 return found ? client_node : NULL;
512 /* string args above */
515 /* Boolean args above */
519 static match_table_t rbd_opts_tokens = {
521 /* string args above */
522 {Opt_read_only, "read_only"},
523 {Opt_read_only, "ro"}, /* Alternate spelling */
524 {Opt_read_write, "read_write"},
525 {Opt_read_write, "rw"}, /* Alternate spelling */
526 /* Boolean args above */
534 #define RBD_READ_ONLY_DEFAULT false
536 static int parse_rbd_opts_token(char *c, void *private)
538 struct rbd_options *rbd_opts = private;
539 substring_t argstr[MAX_OPT_ARGS];
540 int token, intval, ret;
542 token = match_token(c, rbd_opts_tokens, argstr);
546 if (token < Opt_last_int) {
547 ret = match_int(&argstr[0], &intval);
549 pr_err("bad mount option arg (not int) "
553 dout("got int token %d val %d\n", token, intval);
554 } else if (token > Opt_last_int && token < Opt_last_string) {
555 dout("got string token %d val %s\n", token,
557 } else if (token > Opt_last_string && token < Opt_last_bool) {
558 dout("got Boolean token %d\n", token);
560 dout("got token %d\n", token);
565 rbd_opts->read_only = true;
568 rbd_opts->read_only = false;
578 * Get a ceph client with specific addr and configuration, if one does
579 * not exist create it.
581 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
583 struct rbd_client *rbdc;
585 rbdc = rbd_client_find(ceph_opts);
586 if (rbdc) /* using an existing client */
587 ceph_destroy_options(ceph_opts);
589 rbdc = rbd_client_create(ceph_opts);
595 * Destroy ceph client
597 * Caller must hold rbd_client_list_lock.
599 static void rbd_client_release(struct kref *kref)
601 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
603 dout("%s: rbdc %p\n", __func__, rbdc);
604 spin_lock(&rbd_client_list_lock);
605 list_del(&rbdc->node);
606 spin_unlock(&rbd_client_list_lock);
608 ceph_destroy_client(rbdc->client);
613 * Drop reference to ceph client node. If it's not referenced anymore, release
616 static void rbd_put_client(struct rbd_client *rbdc)
619 kref_put(&rbdc->kref, rbd_client_release);
622 static bool rbd_image_format_valid(u32 image_format)
624 return image_format == 1 || image_format == 2;
627 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
632 /* The header has to start with the magic rbd header text */
633 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
636 /* The bio layer requires at least sector-sized I/O */
638 if (ondisk->options.order < SECTOR_SHIFT)
641 /* If we use u64 in a few spots we may be able to loosen this */
643 if (ondisk->options.order > 8 * sizeof (int) - 1)
647 * The size of a snapshot header has to fit in a size_t, and
648 * that limits the number of snapshots.
650 snap_count = le32_to_cpu(ondisk->snap_count);
651 size = SIZE_MAX - sizeof (struct ceph_snap_context);
652 if (snap_count > size / sizeof (__le64))
656 * Not only that, but the size of the entire the snapshot
657 * header must also be representable in a size_t.
659 size -= snap_count * sizeof (__le64);
660 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
667 * Create a new header structure, translate header format from the on-disk
670 static int rbd_header_from_disk(struct rbd_image_header *header,
671 struct rbd_image_header_ondisk *ondisk)
678 memset(header, 0, sizeof (*header));
680 snap_count = le32_to_cpu(ondisk->snap_count);
682 len = strnlen(ondisk->object_prefix, sizeof (ondisk->object_prefix));
683 header->object_prefix = kmalloc(len + 1, GFP_KERNEL);
684 if (!header->object_prefix)
686 memcpy(header->object_prefix, ondisk->object_prefix, len);
687 header->object_prefix[len] = '\0';
690 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
692 /* Save a copy of the snapshot names */
694 if (snap_names_len > (u64) SIZE_MAX)
696 header->snap_names = kmalloc(snap_names_len, GFP_KERNEL);
697 if (!header->snap_names)
700 * Note that rbd_dev_v1_header_read() guarantees
701 * the ondisk buffer we're working with has
702 * snap_names_len bytes beyond the end of the
703 * snapshot id array, this memcpy() is safe.
705 memcpy(header->snap_names, &ondisk->snaps[snap_count],
708 /* Record each snapshot's size */
710 size = snap_count * sizeof (*header->snap_sizes);
711 header->snap_sizes = kmalloc(size, GFP_KERNEL);
712 if (!header->snap_sizes)
714 for (i = 0; i < snap_count; i++)
715 header->snap_sizes[i] =
716 le64_to_cpu(ondisk->snaps[i].image_size);
718 WARN_ON(ondisk->snap_names_len);
719 header->snap_names = NULL;
720 header->snap_sizes = NULL;
723 header->features = 0; /* No features support in v1 images */
724 header->obj_order = ondisk->options.order;
725 header->crypt_type = ondisk->options.crypt_type;
726 header->comp_type = ondisk->options.comp_type;
728 /* Allocate and fill in the snapshot context */
730 header->image_size = le64_to_cpu(ondisk->image_size);
731 size = sizeof (struct ceph_snap_context);
732 size += snap_count * sizeof (header->snapc->snaps[0]);
733 header->snapc = kzalloc(size, GFP_KERNEL);
737 atomic_set(&header->snapc->nref, 1);
738 header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
739 header->snapc->num_snaps = snap_count;
740 for (i = 0; i < snap_count; i++)
741 header->snapc->snaps[i] =
742 le64_to_cpu(ondisk->snaps[i].id);
747 kfree(header->snap_sizes);
748 header->snap_sizes = NULL;
749 kfree(header->snap_names);
750 header->snap_names = NULL;
751 kfree(header->object_prefix);
752 header->object_prefix = NULL;
757 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
759 struct rbd_snap *snap;
761 if (snap_id == CEPH_NOSNAP)
762 return RBD_SNAP_HEAD_NAME;
764 list_for_each_entry(snap, &rbd_dev->snaps, node)
765 if (snap_id == snap->id)
771 static int snap_by_name(struct rbd_device *rbd_dev, const char *snap_name)
774 struct rbd_snap *snap;
776 list_for_each_entry(snap, &rbd_dev->snaps, node) {
777 if (!strcmp(snap_name, snap->name)) {
778 rbd_dev->spec->snap_id = snap->id;
779 rbd_dev->mapping.size = snap->size;
780 rbd_dev->mapping.features = snap->features;
789 static int rbd_dev_set_mapping(struct rbd_device *rbd_dev)
793 if (!memcmp(rbd_dev->spec->snap_name, RBD_SNAP_HEAD_NAME,
794 sizeof (RBD_SNAP_HEAD_NAME))) {
795 rbd_dev->spec->snap_id = CEPH_NOSNAP;
796 rbd_dev->mapping.size = rbd_dev->header.image_size;
797 rbd_dev->mapping.features = rbd_dev->header.features;
800 ret = snap_by_name(rbd_dev, rbd_dev->spec->snap_name);
803 rbd_dev->mapping.read_only = true;
805 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
811 static void rbd_header_free(struct rbd_image_header *header)
813 kfree(header->object_prefix);
814 header->object_prefix = NULL;
815 kfree(header->snap_sizes);
816 header->snap_sizes = NULL;
817 kfree(header->snap_names);
818 header->snap_names = NULL;
819 ceph_put_snap_context(header->snapc);
820 header->snapc = NULL;
823 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
829 name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
832 segment = offset >> rbd_dev->header.obj_order;
833 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
834 rbd_dev->header.object_prefix, segment);
835 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
836 pr_err("error formatting segment name for #%llu (%d)\n",
845 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
847 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
849 return offset & (segment_size - 1);
852 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
853 u64 offset, u64 length)
855 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
857 offset &= segment_size - 1;
859 rbd_assert(length <= U64_MAX - offset);
860 if (offset + length > segment_size)
861 length = segment_size - offset;
867 * returns the size of an object in the image
869 static u64 rbd_obj_bytes(struct rbd_image_header *header)
871 return 1 << header->obj_order;
878 static void bio_chain_put(struct bio *chain)
884 chain = chain->bi_next;
890 * zeros a bio chain, starting at specific offset
892 static void zero_bio_chain(struct bio *chain, int start_ofs)
901 bio_for_each_segment(bv, chain, i) {
902 if (pos + bv->bv_len > start_ofs) {
903 int remainder = max(start_ofs - pos, 0);
904 buf = bvec_kmap_irq(bv, &flags);
905 memset(buf + remainder, 0,
906 bv->bv_len - remainder);
907 bvec_kunmap_irq(buf, &flags);
912 chain = chain->bi_next;
917 * Clone a portion of a bio, starting at the given byte offset
918 * and continuing for the number of bytes indicated.
920 static struct bio *bio_clone_range(struct bio *bio_src,
929 unsigned short end_idx;
933 /* Handle the easy case for the caller */
935 if (!offset && len == bio_src->bi_size)
936 return bio_clone(bio_src, gfpmask);
938 if (WARN_ON_ONCE(!len))
940 if (WARN_ON_ONCE(len > bio_src->bi_size))
942 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
945 /* Find first affected segment... */
948 __bio_for_each_segment(bv, bio_src, idx, 0) {
949 if (resid < bv->bv_len)
955 /* ...and the last affected segment */
958 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
959 if (resid <= bv->bv_len)
963 vcnt = end_idx - idx + 1;
965 /* Build the clone */
967 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
969 return NULL; /* ENOMEM */
971 bio->bi_bdev = bio_src->bi_bdev;
972 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
973 bio->bi_rw = bio_src->bi_rw;
974 bio->bi_flags |= 1 << BIO_CLONED;
977 * Copy over our part of the bio_vec, then update the first
978 * and last (or only) entries.
980 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
981 vcnt * sizeof (struct bio_vec));
982 bio->bi_io_vec[0].bv_offset += voff;
984 bio->bi_io_vec[0].bv_len -= voff;
985 bio->bi_io_vec[vcnt - 1].bv_len = resid;
987 bio->bi_io_vec[0].bv_len = len;
998 * Clone a portion of a bio chain, starting at the given byte offset
999 * into the first bio in the source chain and continuing for the
1000 * number of bytes indicated. The result is another bio chain of
1001 * exactly the given length, or a null pointer on error.
1003 * The bio_src and offset parameters are both in-out. On entry they
1004 * refer to the first source bio and the offset into that bio where
1005 * the start of data to be cloned is located.
1007 * On return, bio_src is updated to refer to the bio in the source
1008 * chain that contains first un-cloned byte, and *offset will
1009 * contain the offset of that byte within that bio.
1011 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1012 unsigned int *offset,
1016 struct bio *bi = *bio_src;
1017 unsigned int off = *offset;
1018 struct bio *chain = NULL;
1021 /* Build up a chain of clone bios up to the limit */
1023 if (!bi || off >= bi->bi_size || !len)
1024 return NULL; /* Nothing to clone */
1028 unsigned int bi_size;
1032 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1033 goto out_err; /* EINVAL; ran out of bio's */
1035 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1036 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1038 goto out_err; /* ENOMEM */
1041 end = &bio->bi_next;
1044 if (off == bi->bi_size) {
1055 bio_chain_put(chain);
1060 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1062 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1063 atomic_read(&obj_request->kref.refcount));
1064 kref_get(&obj_request->kref);
1067 static void rbd_obj_request_destroy(struct kref *kref);
1068 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1070 rbd_assert(obj_request != NULL);
1071 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1072 atomic_read(&obj_request->kref.refcount));
1073 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1076 static void rbd_img_request_get(struct rbd_img_request *img_request)
1078 dout("%s: img %p (was %d)\n", __func__, img_request,
1079 atomic_read(&img_request->kref.refcount));
1080 kref_get(&img_request->kref);
1083 static void rbd_img_request_destroy(struct kref *kref);
1084 static void rbd_img_request_put(struct rbd_img_request *img_request)
1086 rbd_assert(img_request != NULL);
1087 dout("%s: img %p (was %d)\n", __func__, img_request,
1088 atomic_read(&img_request->kref.refcount));
1089 kref_put(&img_request->kref, rbd_img_request_destroy);
1092 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1093 struct rbd_obj_request *obj_request)
1095 rbd_assert(obj_request->img_request == NULL);
1097 rbd_obj_request_get(obj_request);
1098 obj_request->img_request = img_request;
1099 obj_request->which = img_request->obj_request_count;
1100 rbd_assert(obj_request->which != BAD_WHICH);
1101 img_request->obj_request_count++;
1102 list_add_tail(&obj_request->links, &img_request->obj_requests);
1103 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1104 obj_request->which);
1107 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1108 struct rbd_obj_request *obj_request)
1110 rbd_assert(obj_request->which != BAD_WHICH);
1112 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1113 obj_request->which);
1114 list_del(&obj_request->links);
1115 rbd_assert(img_request->obj_request_count > 0);
1116 img_request->obj_request_count--;
1117 rbd_assert(obj_request->which == img_request->obj_request_count);
1118 obj_request->which = BAD_WHICH;
1119 rbd_assert(obj_request->img_request == img_request);
1120 obj_request->img_request = NULL;
1121 obj_request->callback = NULL;
1122 rbd_obj_request_put(obj_request);
1125 static bool obj_request_type_valid(enum obj_request_type type)
1128 case OBJ_REQUEST_NODATA:
1129 case OBJ_REQUEST_BIO:
1130 case OBJ_REQUEST_PAGES:
1137 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1138 struct rbd_obj_request *obj_request)
1140 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1142 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1145 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1147 dout("%s: img %p\n", __func__, img_request);
1148 if (img_request->callback)
1149 img_request->callback(img_request);
1151 rbd_img_request_put(img_request);
1154 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1156 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1158 dout("%s: obj %p\n", __func__, obj_request);
1160 return wait_for_completion_interruptible(&obj_request->completion);
1163 static void obj_request_done_init(struct rbd_obj_request *obj_request)
1165 atomic_set(&obj_request->done, 0);
1169 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1173 done = atomic_inc_return(&obj_request->done);
1175 struct rbd_img_request *img_request = obj_request->img_request;
1176 struct rbd_device *rbd_dev;
1178 rbd_dev = img_request ? img_request->rbd_dev : NULL;
1179 rbd_warn(rbd_dev, "obj_request %p was already done\n",
1184 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1187 return atomic_read(&obj_request->done) != 0;
1191 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1193 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1194 obj_request, obj_request->img_request, obj_request->result,
1195 obj_request->xferred, obj_request->length);
1197 * ENOENT means a hole in the image. We zero-fill the
1198 * entire length of the request. A short read also implies
1199 * zero-fill to the end of the request. Either way we
1200 * update the xferred count to indicate the whole request
1203 BUG_ON(obj_request->type != OBJ_REQUEST_BIO);
1204 if (obj_request->result == -ENOENT) {
1205 zero_bio_chain(obj_request->bio_list, 0);
1206 obj_request->result = 0;
1207 obj_request->xferred = obj_request->length;
1208 } else if (obj_request->xferred < obj_request->length &&
1209 !obj_request->result) {
1210 zero_bio_chain(obj_request->bio_list, obj_request->xferred);
1211 obj_request->xferred = obj_request->length;
1213 obj_request_done_set(obj_request);
1216 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1218 dout("%s: obj %p cb %p\n", __func__, obj_request,
1219 obj_request->callback);
1220 if (obj_request->callback)
1221 obj_request->callback(obj_request);
1223 complete_all(&obj_request->completion);
1226 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1228 dout("%s: obj %p\n", __func__, obj_request);
1229 obj_request_done_set(obj_request);
1232 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1234 dout("%s: obj %p result %d %llu/%llu\n", __func__, obj_request,
1235 obj_request->result, obj_request->xferred, obj_request->length);
1236 if (obj_request->img_request)
1237 rbd_img_obj_request_read_callback(obj_request);
1239 obj_request_done_set(obj_request);
1242 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1244 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1245 obj_request->result, obj_request->length);
1247 * There is no such thing as a successful short write.
1248 * Our xferred value is the number of bytes transferred
1249 * back. Set it to our originally-requested length.
1251 obj_request->xferred = obj_request->length;
1252 obj_request_done_set(obj_request);
1256 * For a simple stat call there's nothing to do. We'll do more if
1257 * this is part of a write sequence for a layered image.
1259 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1261 dout("%s: obj %p\n", __func__, obj_request);
1262 obj_request_done_set(obj_request);
1265 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1266 struct ceph_msg *msg)
1268 struct rbd_obj_request *obj_request = osd_req->r_priv;
1271 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1272 rbd_assert(osd_req == obj_request->osd_req);
1273 rbd_assert(!!obj_request->img_request ^
1274 (obj_request->which == BAD_WHICH));
1276 if (osd_req->r_result < 0)
1277 obj_request->result = osd_req->r_result;
1278 obj_request->version = le64_to_cpu(osd_req->r_reassert_version.version);
1280 WARN_ON(osd_req->r_num_ops != 1); /* For now */
1283 * We support a 64-bit length, but ultimately it has to be
1284 * passed to blk_end_request(), which takes an unsigned int.
1286 obj_request->xferred = osd_req->r_reply_op_len[0];
1287 rbd_assert(obj_request->xferred < (u64) UINT_MAX);
1288 opcode = osd_req->r_ops[0].op;
1290 case CEPH_OSD_OP_READ:
1291 rbd_osd_read_callback(obj_request);
1293 case CEPH_OSD_OP_WRITE:
1294 rbd_osd_write_callback(obj_request);
1296 case CEPH_OSD_OP_STAT:
1297 rbd_osd_stat_callback(obj_request);
1299 case CEPH_OSD_OP_CALL:
1300 case CEPH_OSD_OP_NOTIFY_ACK:
1301 case CEPH_OSD_OP_WATCH:
1302 rbd_osd_trivial_callback(obj_request);
1305 rbd_warn(NULL, "%s: unsupported op %hu\n",
1306 obj_request->object_name, (unsigned short) opcode);
1310 if (obj_request_done_test(obj_request))
1311 rbd_obj_request_complete(obj_request);
1314 static void rbd_osd_req_format_op(struct rbd_obj_request *obj_request,
1317 struct rbd_img_request *img_request = obj_request->img_request;
1318 struct ceph_osd_request *osd_req = obj_request->osd_req;
1319 struct ceph_osd_data *osd_data = NULL;
1320 struct ceph_snap_context *snapc = NULL;
1321 u64 snap_id = CEPH_NOSNAP;
1322 struct timespec *mtime = NULL;
1323 struct timespec now;
1325 rbd_assert(osd_req != NULL);
1327 if (write_request) {
1328 osd_data = &osd_req->r_data_out;
1332 snapc = img_request->snapc;
1334 osd_data = &osd_req->r_data_in;
1336 snap_id = img_request->snap_id;
1338 if (obj_request->type != OBJ_REQUEST_NODATA) {
1340 * If it has data, it's either a object class method
1341 * call (cls) or it's an extent operation.
1343 /* XXX This use of the ops array goes away in the next patch */
1344 if (obj_request->osd_req->r_ops[0].op == CEPH_OSD_OP_CALL)
1345 osd_req_op_cls_response_data(obj_request->osd_req, 0,
1348 osd_req_op_extent_osd_data(obj_request->osd_req, 0,
1351 ceph_osdc_build_request(osd_req, obj_request->offset,
1352 snapc, snap_id, mtime);
1355 static struct ceph_osd_request *rbd_osd_req_create(
1356 struct rbd_device *rbd_dev,
1358 struct rbd_obj_request *obj_request)
1360 struct rbd_img_request *img_request = obj_request->img_request;
1361 struct ceph_snap_context *snapc = NULL;
1362 struct ceph_osd_client *osdc;
1363 struct ceph_osd_request *osd_req;
1364 struct ceph_osd_data *osd_data;
1365 u64 offset = obj_request->offset;
1368 rbd_assert(img_request->write_request == write_request);
1369 if (img_request->write_request)
1370 snapc = img_request->snapc;
1373 /* Allocate and initialize the request, for the single op */
1375 osdc = &rbd_dev->rbd_client->client->osdc;
1376 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1378 return NULL; /* ENOMEM */
1379 osd_data = write_request ? &osd_req->r_data_out : &osd_req->r_data_in;
1381 rbd_assert(obj_request_type_valid(obj_request->type));
1382 switch (obj_request->type) {
1383 case OBJ_REQUEST_NODATA:
1384 break; /* Nothing to do */
1385 case OBJ_REQUEST_BIO:
1386 rbd_assert(obj_request->bio_list != NULL);
1387 ceph_osd_data_bio_init(osd_data, obj_request->bio_list,
1388 obj_request->length);
1390 case OBJ_REQUEST_PAGES:
1391 ceph_osd_data_pages_init(osd_data, obj_request->pages,
1392 obj_request->length, offset & ~PAGE_MASK,
1398 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1400 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1402 osd_req->r_callback = rbd_osd_req_callback;
1403 osd_req->r_priv = obj_request;
1405 osd_req->r_oid_len = strlen(obj_request->object_name);
1406 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1407 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1409 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1414 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1416 ceph_osdc_put_request(osd_req);
1419 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1421 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1422 u64 offset, u64 length,
1423 enum obj_request_type type)
1425 struct rbd_obj_request *obj_request;
1429 rbd_assert(obj_request_type_valid(type));
1431 size = strlen(object_name) + 1;
1432 obj_request = kzalloc(sizeof (*obj_request) + size, GFP_KERNEL);
1436 name = (char *)(obj_request + 1);
1437 obj_request->object_name = memcpy(name, object_name, size);
1438 obj_request->offset = offset;
1439 obj_request->length = length;
1440 obj_request->which = BAD_WHICH;
1441 obj_request->type = type;
1442 INIT_LIST_HEAD(&obj_request->links);
1443 obj_request_done_init(obj_request);
1444 init_completion(&obj_request->completion);
1445 kref_init(&obj_request->kref);
1447 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1448 offset, length, (int)type, obj_request);
1453 static void rbd_obj_request_destroy(struct kref *kref)
1455 struct rbd_obj_request *obj_request;
1457 obj_request = container_of(kref, struct rbd_obj_request, kref);
1459 dout("%s: obj %p\n", __func__, obj_request);
1461 rbd_assert(obj_request->img_request == NULL);
1462 rbd_assert(obj_request->which == BAD_WHICH);
1464 if (obj_request->osd_req)
1465 rbd_osd_req_destroy(obj_request->osd_req);
1467 rbd_assert(obj_request_type_valid(obj_request->type));
1468 switch (obj_request->type) {
1469 case OBJ_REQUEST_NODATA:
1470 break; /* Nothing to do */
1471 case OBJ_REQUEST_BIO:
1472 if (obj_request->bio_list)
1473 bio_chain_put(obj_request->bio_list);
1475 case OBJ_REQUEST_PAGES:
1476 if (obj_request->pages)
1477 ceph_release_page_vector(obj_request->pages,
1478 obj_request->page_count);
1486 * Caller is responsible for filling in the list of object requests
1487 * that comprises the image request, and the Linux request pointer
1488 * (if there is one).
1490 static struct rbd_img_request *rbd_img_request_create(
1491 struct rbd_device *rbd_dev,
1492 u64 offset, u64 length,
1495 struct rbd_img_request *img_request;
1496 struct ceph_snap_context *snapc = NULL;
1498 img_request = kmalloc(sizeof (*img_request), GFP_ATOMIC);
1502 if (write_request) {
1503 down_read(&rbd_dev->header_rwsem);
1504 snapc = ceph_get_snap_context(rbd_dev->header.snapc);
1505 up_read(&rbd_dev->header_rwsem);
1506 if (WARN_ON(!snapc)) {
1508 return NULL; /* Shouldn't happen */
1512 img_request->rq = NULL;
1513 img_request->rbd_dev = rbd_dev;
1514 img_request->offset = offset;
1515 img_request->length = length;
1516 img_request->write_request = write_request;
1518 img_request->snapc = snapc;
1520 img_request->snap_id = rbd_dev->spec->snap_id;
1521 spin_lock_init(&img_request->completion_lock);
1522 img_request->next_completion = 0;
1523 img_request->callback = NULL;
1524 img_request->obj_request_count = 0;
1525 INIT_LIST_HEAD(&img_request->obj_requests);
1526 kref_init(&img_request->kref);
1528 rbd_img_request_get(img_request); /* Avoid a warning */
1529 rbd_img_request_put(img_request); /* TEMPORARY */
1531 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1532 write_request ? "write" : "read", offset, length,
1538 static void rbd_img_request_destroy(struct kref *kref)
1540 struct rbd_img_request *img_request;
1541 struct rbd_obj_request *obj_request;
1542 struct rbd_obj_request *next_obj_request;
1544 img_request = container_of(kref, struct rbd_img_request, kref);
1546 dout("%s: img %p\n", __func__, img_request);
1548 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1549 rbd_img_obj_request_del(img_request, obj_request);
1550 rbd_assert(img_request->obj_request_count == 0);
1552 if (img_request->write_request)
1553 ceph_put_snap_context(img_request->snapc);
1558 static int rbd_img_request_fill_bio(struct rbd_img_request *img_request,
1559 struct bio *bio_list)
1561 struct rbd_device *rbd_dev = img_request->rbd_dev;
1562 struct rbd_obj_request *obj_request = NULL;
1563 struct rbd_obj_request *next_obj_request;
1564 bool write_request = img_request->write_request;
1565 unsigned int bio_offset;
1570 dout("%s: img %p bio %p\n", __func__, img_request, bio_list);
1572 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
1574 image_offset = img_request->offset;
1575 rbd_assert(image_offset == bio_list->bi_sector << SECTOR_SHIFT);
1576 resid = img_request->length;
1577 rbd_assert(resid > 0);
1579 const char *object_name;
1580 unsigned int clone_size;
1584 object_name = rbd_segment_name(rbd_dev, image_offset);
1587 offset = rbd_segment_offset(rbd_dev, image_offset);
1588 length = rbd_segment_length(rbd_dev, image_offset, resid);
1589 obj_request = rbd_obj_request_create(object_name,
1592 kfree(object_name); /* object request has its own copy */
1596 rbd_assert(length <= (u64) UINT_MAX);
1597 clone_size = (unsigned int) length;
1598 obj_request->bio_list = bio_chain_clone_range(&bio_list,
1599 &bio_offset, clone_size,
1601 if (!obj_request->bio_list)
1604 obj_request->osd_req = rbd_osd_req_create(rbd_dev,
1605 write_request, obj_request);
1606 if (!obj_request->osd_req)
1609 osd_req_op_extent_init(obj_request->osd_req, 0,
1610 opcode, offset, length, 0, 0);
1611 rbd_osd_req_format_op(obj_request, write_request);
1613 /* status and version are initially zero-filled */
1615 rbd_img_obj_request_add(img_request, obj_request);
1617 image_offset += length;
1624 rbd_obj_request_put(obj_request);
1626 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1627 rbd_obj_request_put(obj_request);
1632 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1634 struct rbd_img_request *img_request;
1635 u32 which = obj_request->which;
1638 img_request = obj_request->img_request;
1640 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1641 rbd_assert(img_request != NULL);
1642 rbd_assert(img_request->rq != NULL);
1643 rbd_assert(img_request->obj_request_count > 0);
1644 rbd_assert(which != BAD_WHICH);
1645 rbd_assert(which < img_request->obj_request_count);
1646 rbd_assert(which >= img_request->next_completion);
1648 spin_lock_irq(&img_request->completion_lock);
1649 if (which != img_request->next_completion)
1652 for_each_obj_request_from(img_request, obj_request) {
1653 unsigned int xferred;
1657 rbd_assert(which < img_request->obj_request_count);
1659 if (!obj_request_done_test(obj_request))
1662 rbd_assert(obj_request->xferred <= (u64) UINT_MAX);
1663 xferred = (unsigned int) obj_request->xferred;
1664 result = (int) obj_request->result;
1666 rbd_warn(NULL, "obj_request %s result %d xferred %u\n",
1667 img_request->write_request ? "write" : "read",
1670 more = blk_end_request(img_request->rq, result, xferred);
1674 rbd_assert(more ^ (which == img_request->obj_request_count));
1675 img_request->next_completion = which;
1677 spin_unlock_irq(&img_request->completion_lock);
1680 rbd_img_request_complete(img_request);
1683 static int rbd_img_request_submit(struct rbd_img_request *img_request)
1685 struct rbd_device *rbd_dev = img_request->rbd_dev;
1686 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
1687 struct rbd_obj_request *obj_request;
1688 struct rbd_obj_request *next_obj_request;
1690 dout("%s: img %p\n", __func__, img_request);
1691 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
1694 obj_request->callback = rbd_img_obj_callback;
1695 ret = rbd_obj_request_submit(osdc, obj_request);
1699 * The image request has its own reference to each
1700 * of its object requests, so we can safely drop the
1703 rbd_obj_request_put(obj_request);
1709 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev,
1710 u64 ver, u64 notify_id)
1712 struct rbd_obj_request *obj_request;
1713 struct ceph_osd_client *osdc;
1716 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
1717 OBJ_REQUEST_NODATA);
1722 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
1723 if (!obj_request->osd_req)
1726 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
1728 rbd_osd_req_format_op(obj_request, false);
1730 osdc = &rbd_dev->rbd_client->client->osdc;
1731 obj_request->callback = rbd_obj_request_put;
1732 ret = rbd_obj_request_submit(osdc, obj_request);
1735 rbd_obj_request_put(obj_request);
1740 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
1742 struct rbd_device *rbd_dev = (struct rbd_device *)data;
1749 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
1750 rbd_dev->header_name, (unsigned long long) notify_id,
1751 (unsigned int) opcode);
1752 rc = rbd_dev_refresh(rbd_dev, &hver);
1754 rbd_warn(rbd_dev, "got notification but failed to "
1755 " update snaps: %d\n", rc);
1757 rbd_obj_notify_ack(rbd_dev, hver, notify_id);
1761 * Request sync osd watch/unwatch. The value of "start" determines
1762 * whether a watch request is being initiated or torn down.
1764 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start)
1766 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
1767 struct rbd_obj_request *obj_request;
1770 rbd_assert(start ^ !!rbd_dev->watch_event);
1771 rbd_assert(start ^ !!rbd_dev->watch_request);
1774 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
1775 &rbd_dev->watch_event);
1778 rbd_assert(rbd_dev->watch_event != NULL);
1782 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
1783 OBJ_REQUEST_NODATA);
1787 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
1788 if (!obj_request->osd_req)
1791 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
1792 rbd_dev->watch_event->cookie,
1793 rbd_dev->header.obj_version, start);
1794 rbd_osd_req_format_op(obj_request, true);
1797 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
1799 ceph_osdc_unregister_linger_request(osdc,
1800 rbd_dev->watch_request->osd_req);
1801 ret = rbd_obj_request_submit(osdc, obj_request);
1804 ret = rbd_obj_request_wait(obj_request);
1807 ret = obj_request->result;
1812 * A watch request is set to linger, so the underlying osd
1813 * request won't go away until we unregister it. We retain
1814 * a pointer to the object request during that time (in
1815 * rbd_dev->watch_request), so we'll keep a reference to
1816 * it. We'll drop that reference (below) after we've
1820 rbd_dev->watch_request = obj_request;
1825 /* We have successfully torn down the watch request */
1827 rbd_obj_request_put(rbd_dev->watch_request);
1828 rbd_dev->watch_request = NULL;
1830 /* Cancel the event if we're tearing down, or on error */
1831 ceph_osdc_cancel_event(rbd_dev->watch_event);
1832 rbd_dev->watch_event = NULL;
1834 rbd_obj_request_put(obj_request);
1840 * Synchronous osd object method call
1842 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
1843 const char *object_name,
1844 const char *class_name,
1845 const char *method_name,
1846 const char *outbound,
1847 size_t outbound_size,
1849 size_t inbound_size,
1852 struct rbd_obj_request *obj_request;
1853 struct ceph_osd_client *osdc;
1854 struct page **pages;
1859 * Method calls are ultimately read operations. The result
1860 * should placed into the inbound buffer provided. They
1861 * also supply outbound data--parameters for the object
1862 * method. Currently if this is present it will be a
1865 page_count = (u32) calc_pages_for(0, inbound_size);
1866 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
1868 return PTR_ERR(pages);
1871 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
1876 obj_request->pages = pages;
1877 obj_request->page_count = page_count;
1879 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
1880 if (!obj_request->osd_req)
1883 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
1884 class_name, method_name,
1885 outbound, outbound_size);
1886 rbd_osd_req_format_op(obj_request, false);
1888 osdc = &rbd_dev->rbd_client->client->osdc;
1889 ret = rbd_obj_request_submit(osdc, obj_request);
1892 ret = rbd_obj_request_wait(obj_request);
1896 ret = obj_request->result;
1900 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
1902 *version = obj_request->version;
1905 rbd_obj_request_put(obj_request);
1907 ceph_release_page_vector(pages, page_count);
1912 static void rbd_request_fn(struct request_queue *q)
1913 __releases(q->queue_lock) __acquires(q->queue_lock)
1915 struct rbd_device *rbd_dev = q->queuedata;
1916 bool read_only = rbd_dev->mapping.read_only;
1920 while ((rq = blk_fetch_request(q))) {
1921 bool write_request = rq_data_dir(rq) == WRITE;
1922 struct rbd_img_request *img_request;
1926 /* Ignore any non-FS requests that filter through. */
1928 if (rq->cmd_type != REQ_TYPE_FS) {
1929 dout("%s: non-fs request type %d\n", __func__,
1930 (int) rq->cmd_type);
1931 __blk_end_request_all(rq, 0);
1935 /* Ignore/skip any zero-length requests */
1937 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
1938 length = (u64) blk_rq_bytes(rq);
1941 dout("%s: zero-length request\n", __func__);
1942 __blk_end_request_all(rq, 0);
1946 spin_unlock_irq(q->queue_lock);
1948 /* Disallow writes to a read-only device */
1950 if (write_request) {
1954 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
1958 * Quit early if the mapped snapshot no longer
1959 * exists. It's still possible the snapshot will
1960 * have disappeared by the time our request arrives
1961 * at the osd, but there's no sense in sending it if
1964 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
1965 dout("request for non-existent snapshot");
1966 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
1972 if (WARN_ON(offset && length > U64_MAX - offset + 1))
1973 goto end_request; /* Shouldn't happen */
1976 img_request = rbd_img_request_create(rbd_dev, offset, length,
1981 img_request->rq = rq;
1983 result = rbd_img_request_fill_bio(img_request, rq->bio);
1985 result = rbd_img_request_submit(img_request);
1987 rbd_img_request_put(img_request);
1989 spin_lock_irq(q->queue_lock);
1991 rbd_warn(rbd_dev, "obj_request %s result %d\n",
1992 write_request ? "write" : "read", result);
1993 __blk_end_request_all(rq, result);
1999 * a queue callback. Makes sure that we don't create a bio that spans across
2000 * multiple osd objects. One exception would be with a single page bios,
2001 * which we handle later at bio_chain_clone_range()
2003 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2004 struct bio_vec *bvec)
2006 struct rbd_device *rbd_dev = q->queuedata;
2007 sector_t sector_offset;
2008 sector_t sectors_per_obj;
2009 sector_t obj_sector_offset;
2013 * Find how far into its rbd object the partition-relative
2014 * bio start sector is to offset relative to the enclosing
2017 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2018 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2019 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2022 * Compute the number of bytes from that offset to the end
2023 * of the object. Account for what's already used by the bio.
2025 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2026 if (ret > bmd->bi_size)
2027 ret -= bmd->bi_size;
2032 * Don't send back more than was asked for. And if the bio
2033 * was empty, let the whole thing through because: "Note
2034 * that a block device *must* allow a single page to be
2035 * added to an empty bio."
2037 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2038 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2039 ret = (int) bvec->bv_len;
2044 static void rbd_free_disk(struct rbd_device *rbd_dev)
2046 struct gendisk *disk = rbd_dev->disk;
2051 if (disk->flags & GENHD_FL_UP)
2054 blk_cleanup_queue(disk->queue);
2058 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2059 const char *object_name,
2060 u64 offset, u64 length,
2061 char *buf, u64 *version)
2064 struct rbd_obj_request *obj_request;
2065 struct ceph_osd_client *osdc;
2066 struct page **pages = NULL;
2071 page_count = (u32) calc_pages_for(offset, length);
2072 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2074 ret = PTR_ERR(pages);
2077 obj_request = rbd_obj_request_create(object_name, offset, length,
2082 obj_request->pages = pages;
2083 obj_request->page_count = page_count;
2085 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2086 if (!obj_request->osd_req)
2089 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
2090 offset, length, 0, 0);
2091 rbd_osd_req_format_op(obj_request, false);
2093 osdc = &rbd_dev->rbd_client->client->osdc;
2094 ret = rbd_obj_request_submit(osdc, obj_request);
2097 ret = rbd_obj_request_wait(obj_request);
2101 ret = obj_request->result;
2105 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
2106 size = (size_t) obj_request->xferred;
2107 ceph_copy_from_page_vector(pages, buf, 0, size);
2108 rbd_assert(size <= (size_t) INT_MAX);
2111 *version = obj_request->version;
2114 rbd_obj_request_put(obj_request);
2116 ceph_release_page_vector(pages, page_count);
2122 * Read the complete header for the given rbd device.
2124 * Returns a pointer to a dynamically-allocated buffer containing
2125 * the complete and validated header. Caller can pass the address
2126 * of a variable that will be filled in with the version of the
2127 * header object at the time it was read.
2129 * Returns a pointer-coded errno if a failure occurs.
2131 static struct rbd_image_header_ondisk *
2132 rbd_dev_v1_header_read(struct rbd_device *rbd_dev, u64 *version)
2134 struct rbd_image_header_ondisk *ondisk = NULL;
2141 * The complete header will include an array of its 64-bit
2142 * snapshot ids, followed by the names of those snapshots as
2143 * a contiguous block of NUL-terminated strings. Note that
2144 * the number of snapshots could change by the time we read
2145 * it in, in which case we re-read it.
2152 size = sizeof (*ondisk);
2153 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
2155 ondisk = kmalloc(size, GFP_KERNEL);
2157 return ERR_PTR(-ENOMEM);
2159 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
2161 (char *) ondisk, version);
2164 if (WARN_ON((size_t) ret < size)) {
2166 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
2170 if (!rbd_dev_ondisk_valid(ondisk)) {
2172 rbd_warn(rbd_dev, "invalid header");
2176 names_size = le64_to_cpu(ondisk->snap_names_len);
2177 want_count = snap_count;
2178 snap_count = le32_to_cpu(ondisk->snap_count);
2179 } while (snap_count != want_count);
2186 return ERR_PTR(ret);
2190 * reload the ondisk the header
2192 static int rbd_read_header(struct rbd_device *rbd_dev,
2193 struct rbd_image_header *header)
2195 struct rbd_image_header_ondisk *ondisk;
2199 ondisk = rbd_dev_v1_header_read(rbd_dev, &ver);
2201 return PTR_ERR(ondisk);
2202 ret = rbd_header_from_disk(header, ondisk);
2204 header->obj_version = ver;
2210 static void rbd_remove_all_snaps(struct rbd_device *rbd_dev)
2212 struct rbd_snap *snap;
2213 struct rbd_snap *next;
2215 list_for_each_entry_safe(snap, next, &rbd_dev->snaps, node)
2216 rbd_remove_snap_dev(snap);
2219 static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
2223 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
2226 size = (sector_t) rbd_dev->header.image_size / SECTOR_SIZE;
2227 dout("setting size to %llu sectors", (unsigned long long) size);
2228 rbd_dev->mapping.size = (u64) size;
2229 set_capacity(rbd_dev->disk, size);
2233 * only read the first part of the ondisk header, without the snaps info
2235 static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev, u64 *hver)
2238 struct rbd_image_header h;
2240 ret = rbd_read_header(rbd_dev, &h);
2244 down_write(&rbd_dev->header_rwsem);
2246 /* Update image size, and check for resize of mapped image */
2247 rbd_dev->header.image_size = h.image_size;
2248 rbd_update_mapping_size(rbd_dev);
2250 /* rbd_dev->header.object_prefix shouldn't change */
2251 kfree(rbd_dev->header.snap_sizes);
2252 kfree(rbd_dev->header.snap_names);
2253 /* osd requests may still refer to snapc */
2254 ceph_put_snap_context(rbd_dev->header.snapc);
2257 *hver = h.obj_version;
2258 rbd_dev->header.obj_version = h.obj_version;
2259 rbd_dev->header.image_size = h.image_size;
2260 rbd_dev->header.snapc = h.snapc;
2261 rbd_dev->header.snap_names = h.snap_names;
2262 rbd_dev->header.snap_sizes = h.snap_sizes;
2263 /* Free the extra copy of the object prefix */
2264 WARN_ON(strcmp(rbd_dev->header.object_prefix, h.object_prefix));
2265 kfree(h.object_prefix);
2267 ret = rbd_dev_snaps_update(rbd_dev);
2269 ret = rbd_dev_snaps_register(rbd_dev);
2271 up_write(&rbd_dev->header_rwsem);
2276 static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver)
2280 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
2281 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2282 if (rbd_dev->image_format == 1)
2283 ret = rbd_dev_v1_refresh(rbd_dev, hver);
2285 ret = rbd_dev_v2_refresh(rbd_dev, hver);
2286 mutex_unlock(&ctl_mutex);
2291 static int rbd_init_disk(struct rbd_device *rbd_dev)
2293 struct gendisk *disk;
2294 struct request_queue *q;
2297 /* create gendisk info */
2298 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
2302 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
2304 disk->major = rbd_dev->major;
2305 disk->first_minor = 0;
2306 disk->fops = &rbd_bd_ops;
2307 disk->private_data = rbd_dev;
2309 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
2313 /* We use the default size, but let's be explicit about it. */
2314 blk_queue_physical_block_size(q, SECTOR_SIZE);
2316 /* set io sizes to object size */
2317 segment_size = rbd_obj_bytes(&rbd_dev->header);
2318 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
2319 blk_queue_max_segment_size(q, segment_size);
2320 blk_queue_io_min(q, segment_size);
2321 blk_queue_io_opt(q, segment_size);
2323 blk_queue_merge_bvec(q, rbd_merge_bvec);
2326 q->queuedata = rbd_dev;
2328 rbd_dev->disk = disk;
2330 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
2343 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
2345 return container_of(dev, struct rbd_device, dev);
2348 static ssize_t rbd_size_show(struct device *dev,
2349 struct device_attribute *attr, char *buf)
2351 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2354 down_read(&rbd_dev->header_rwsem);
2355 size = get_capacity(rbd_dev->disk);
2356 up_read(&rbd_dev->header_rwsem);
2358 return sprintf(buf, "%llu\n", (unsigned long long) size * SECTOR_SIZE);
2362 * Note this shows the features for whatever's mapped, which is not
2363 * necessarily the base image.
2365 static ssize_t rbd_features_show(struct device *dev,
2366 struct device_attribute *attr, char *buf)
2368 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2370 return sprintf(buf, "0x%016llx\n",
2371 (unsigned long long) rbd_dev->mapping.features);
2374 static ssize_t rbd_major_show(struct device *dev,
2375 struct device_attribute *attr, char *buf)
2377 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2379 return sprintf(buf, "%d\n", rbd_dev->major);
2382 static ssize_t rbd_client_id_show(struct device *dev,
2383 struct device_attribute *attr, char *buf)
2385 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2387 return sprintf(buf, "client%lld\n",
2388 ceph_client_id(rbd_dev->rbd_client->client));
2391 static ssize_t rbd_pool_show(struct device *dev,
2392 struct device_attribute *attr, char *buf)
2394 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2396 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
2399 static ssize_t rbd_pool_id_show(struct device *dev,
2400 struct device_attribute *attr, char *buf)
2402 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2404 return sprintf(buf, "%llu\n",
2405 (unsigned long long) rbd_dev->spec->pool_id);
2408 static ssize_t rbd_name_show(struct device *dev,
2409 struct device_attribute *attr, char *buf)
2411 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2413 if (rbd_dev->spec->image_name)
2414 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
2416 return sprintf(buf, "(unknown)\n");
2419 static ssize_t rbd_image_id_show(struct device *dev,
2420 struct device_attribute *attr, char *buf)
2422 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2424 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
2428 * Shows the name of the currently-mapped snapshot (or
2429 * RBD_SNAP_HEAD_NAME for the base image).
2431 static ssize_t rbd_snap_show(struct device *dev,
2432 struct device_attribute *attr,
2435 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2437 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
2441 * For an rbd v2 image, shows the pool id, image id, and snapshot id
2442 * for the parent image. If there is no parent, simply shows
2443 * "(no parent image)".
2445 static ssize_t rbd_parent_show(struct device *dev,
2446 struct device_attribute *attr,
2449 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2450 struct rbd_spec *spec = rbd_dev->parent_spec;
2455 return sprintf(buf, "(no parent image)\n");
2457 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
2458 (unsigned long long) spec->pool_id, spec->pool_name);
2463 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
2464 spec->image_name ? spec->image_name : "(unknown)");
2469 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
2470 (unsigned long long) spec->snap_id, spec->snap_name);
2475 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
2480 return (ssize_t) (bufp - buf);
2483 static ssize_t rbd_image_refresh(struct device *dev,
2484 struct device_attribute *attr,
2488 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
2491 ret = rbd_dev_refresh(rbd_dev, NULL);
2493 return ret < 0 ? ret : size;
2496 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
2497 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
2498 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
2499 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
2500 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
2501 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
2502 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
2503 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
2504 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
2505 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
2506 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
2508 static struct attribute *rbd_attrs[] = {
2509 &dev_attr_size.attr,
2510 &dev_attr_features.attr,
2511 &dev_attr_major.attr,
2512 &dev_attr_client_id.attr,
2513 &dev_attr_pool.attr,
2514 &dev_attr_pool_id.attr,
2515 &dev_attr_name.attr,
2516 &dev_attr_image_id.attr,
2517 &dev_attr_current_snap.attr,
2518 &dev_attr_parent.attr,
2519 &dev_attr_refresh.attr,
2523 static struct attribute_group rbd_attr_group = {
2527 static const struct attribute_group *rbd_attr_groups[] = {
2532 static void rbd_sysfs_dev_release(struct device *dev)
2536 static struct device_type rbd_device_type = {
2538 .groups = rbd_attr_groups,
2539 .release = rbd_sysfs_dev_release,
2547 static ssize_t rbd_snap_size_show(struct device *dev,
2548 struct device_attribute *attr,
2551 struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
2553 return sprintf(buf, "%llu\n", (unsigned long long)snap->size);
2556 static ssize_t rbd_snap_id_show(struct device *dev,
2557 struct device_attribute *attr,
2560 struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
2562 return sprintf(buf, "%llu\n", (unsigned long long)snap->id);
2565 static ssize_t rbd_snap_features_show(struct device *dev,
2566 struct device_attribute *attr,
2569 struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
2571 return sprintf(buf, "0x%016llx\n",
2572 (unsigned long long) snap->features);
2575 static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL);
2576 static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
2577 static DEVICE_ATTR(snap_features, S_IRUGO, rbd_snap_features_show, NULL);
2579 static struct attribute *rbd_snap_attrs[] = {
2580 &dev_attr_snap_size.attr,
2581 &dev_attr_snap_id.attr,
2582 &dev_attr_snap_features.attr,
2586 static struct attribute_group rbd_snap_attr_group = {
2587 .attrs = rbd_snap_attrs,
2590 static void rbd_snap_dev_release(struct device *dev)
2592 struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
2597 static const struct attribute_group *rbd_snap_attr_groups[] = {
2598 &rbd_snap_attr_group,
2602 static struct device_type rbd_snap_device_type = {
2603 .groups = rbd_snap_attr_groups,
2604 .release = rbd_snap_dev_release,
2607 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
2609 kref_get(&spec->kref);
2614 static void rbd_spec_free(struct kref *kref);
2615 static void rbd_spec_put(struct rbd_spec *spec)
2618 kref_put(&spec->kref, rbd_spec_free);
2621 static struct rbd_spec *rbd_spec_alloc(void)
2623 struct rbd_spec *spec;
2625 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
2628 kref_init(&spec->kref);
2630 rbd_spec_put(rbd_spec_get(spec)); /* TEMPORARY */
2635 static void rbd_spec_free(struct kref *kref)
2637 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
2639 kfree(spec->pool_name);
2640 kfree(spec->image_id);
2641 kfree(spec->image_name);
2642 kfree(spec->snap_name);
2646 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
2647 struct rbd_spec *spec)
2649 struct rbd_device *rbd_dev;
2651 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
2655 spin_lock_init(&rbd_dev->lock);
2657 INIT_LIST_HEAD(&rbd_dev->node);
2658 INIT_LIST_HEAD(&rbd_dev->snaps);
2659 init_rwsem(&rbd_dev->header_rwsem);
2661 rbd_dev->spec = spec;
2662 rbd_dev->rbd_client = rbdc;
2664 /* Initialize the layout used for all rbd requests */
2666 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
2667 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
2668 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
2669 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
2674 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
2676 rbd_spec_put(rbd_dev->parent_spec);
2677 kfree(rbd_dev->header_name);
2678 rbd_put_client(rbd_dev->rbd_client);
2679 rbd_spec_put(rbd_dev->spec);
2683 static bool rbd_snap_registered(struct rbd_snap *snap)
2685 bool ret = snap->dev.type == &rbd_snap_device_type;
2686 bool reg = device_is_registered(&snap->dev);
2688 rbd_assert(!ret ^ reg);
2693 static void rbd_remove_snap_dev(struct rbd_snap *snap)
2695 list_del(&snap->node);
2696 if (device_is_registered(&snap->dev))
2697 device_unregister(&snap->dev);
2700 static int rbd_register_snap_dev(struct rbd_snap *snap,
2701 struct device *parent)
2703 struct device *dev = &snap->dev;
2706 dev->type = &rbd_snap_device_type;
2707 dev->parent = parent;
2708 dev->release = rbd_snap_dev_release;
2709 dev_set_name(dev, "%s%s", RBD_SNAP_DEV_NAME_PREFIX, snap->name);
2710 dout("%s: registering device for snapshot %s\n", __func__, snap->name);
2712 ret = device_register(dev);
2717 static struct rbd_snap *__rbd_add_snap_dev(struct rbd_device *rbd_dev,
2718 const char *snap_name,
2719 u64 snap_id, u64 snap_size,
2722 struct rbd_snap *snap;
2725 snap = kzalloc(sizeof (*snap), GFP_KERNEL);
2727 return ERR_PTR(-ENOMEM);
2730 snap->name = kstrdup(snap_name, GFP_KERNEL);
2735 snap->size = snap_size;
2736 snap->features = snap_features;
2744 return ERR_PTR(ret);
2747 static char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which,
2748 u64 *snap_size, u64 *snap_features)
2752 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
2754 *snap_size = rbd_dev->header.snap_sizes[which];
2755 *snap_features = 0; /* No features for v1 */
2757 /* Skip over names until we find the one we are looking for */
2759 snap_name = rbd_dev->header.snap_names;
2761 snap_name += strlen(snap_name) + 1;
2767 * Get the size and object order for an image snapshot, or if
2768 * snap_id is CEPH_NOSNAP, gets this information for the base
2771 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
2772 u8 *order, u64 *snap_size)
2774 __le64 snapid = cpu_to_le64(snap_id);
2779 } __attribute__ ((packed)) size_buf = { 0 };
2781 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
2783 (char *) &snapid, sizeof (snapid),
2784 (char *) &size_buf, sizeof (size_buf), NULL);
2785 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
2789 *order = size_buf.order;
2790 *snap_size = le64_to_cpu(size_buf.size);
2792 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
2793 (unsigned long long) snap_id, (unsigned int) *order,
2794 (unsigned long long) *snap_size);
2799 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
2801 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
2802 &rbd_dev->header.obj_order,
2803 &rbd_dev->header.image_size);
2806 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
2812 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
2816 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
2817 "rbd", "get_object_prefix",
2819 reply_buf, RBD_OBJ_PREFIX_LEN_MAX, NULL);
2820 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
2825 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
2826 p + RBD_OBJ_PREFIX_LEN_MAX,
2829 if (IS_ERR(rbd_dev->header.object_prefix)) {
2830 ret = PTR_ERR(rbd_dev->header.object_prefix);
2831 rbd_dev->header.object_prefix = NULL;
2833 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
2842 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
2845 __le64 snapid = cpu_to_le64(snap_id);
2849 } features_buf = { 0 };
2853 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
2854 "rbd", "get_features",
2855 (char *) &snapid, sizeof (snapid),
2856 (char *) &features_buf, sizeof (features_buf),
2858 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
2862 incompat = le64_to_cpu(features_buf.incompat);
2863 if (incompat & ~RBD_FEATURES_ALL)
2866 *snap_features = le64_to_cpu(features_buf.features);
2868 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
2869 (unsigned long long) snap_id,
2870 (unsigned long long) *snap_features,
2871 (unsigned long long) le64_to_cpu(features_buf.incompat));
2876 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
2878 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
2879 &rbd_dev->header.features);
2882 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
2884 struct rbd_spec *parent_spec;
2886 void *reply_buf = NULL;
2894 parent_spec = rbd_spec_alloc();
2898 size = sizeof (__le64) + /* pool_id */
2899 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
2900 sizeof (__le64) + /* snap_id */
2901 sizeof (__le64); /* overlap */
2902 reply_buf = kmalloc(size, GFP_KERNEL);
2908 snapid = cpu_to_le64(CEPH_NOSNAP);
2909 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
2910 "rbd", "get_parent",
2911 (char *) &snapid, sizeof (snapid),
2912 (char *) reply_buf, size, NULL);
2913 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
2919 end = (char *) reply_buf + size;
2920 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
2921 if (parent_spec->pool_id == CEPH_NOPOOL)
2922 goto out; /* No parent? No problem. */
2924 /* The ceph file layout needs to fit pool id in 32 bits */
2927 if (WARN_ON(parent_spec->pool_id > (u64) U32_MAX))
2930 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
2931 if (IS_ERR(image_id)) {
2932 ret = PTR_ERR(image_id);
2935 parent_spec->image_id = image_id;
2936 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
2937 ceph_decode_64_safe(&p, end, overlap, out_err);
2939 rbd_dev->parent_overlap = overlap;
2940 rbd_dev->parent_spec = parent_spec;
2941 parent_spec = NULL; /* rbd_dev now owns this */
2946 rbd_spec_put(parent_spec);
2951 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
2953 size_t image_id_size;
2958 void *reply_buf = NULL;
2960 char *image_name = NULL;
2963 rbd_assert(!rbd_dev->spec->image_name);
2965 len = strlen(rbd_dev->spec->image_id);
2966 image_id_size = sizeof (__le32) + len;
2967 image_id = kmalloc(image_id_size, GFP_KERNEL);
2972 end = (char *) image_id + image_id_size;
2973 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32) len);
2975 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
2976 reply_buf = kmalloc(size, GFP_KERNEL);
2980 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
2981 "rbd", "dir_get_name",
2982 image_id, image_id_size,
2983 (char *) reply_buf, size, NULL);
2987 end = (char *) reply_buf + size;
2988 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
2989 if (IS_ERR(image_name))
2992 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3001 * When a parent image gets probed, we only have the pool, image,
3002 * and snapshot ids but not the names of any of them. This call
3003 * is made later to fill in those names. It has to be done after
3004 * rbd_dev_snaps_update() has completed because some of the
3005 * information (in particular, snapshot name) is not available
3008 static int rbd_dev_probe_update_spec(struct rbd_device *rbd_dev)
3010 struct ceph_osd_client *osdc;
3012 void *reply_buf = NULL;
3015 if (rbd_dev->spec->pool_name)
3016 return 0; /* Already have the names */
3018 /* Look up the pool name */
3020 osdc = &rbd_dev->rbd_client->client->osdc;
3021 name = ceph_pg_pool_name_by_id(osdc->osdmap, rbd_dev->spec->pool_id);
3023 rbd_warn(rbd_dev, "there is no pool with id %llu",
3024 rbd_dev->spec->pool_id); /* Really a BUG() */
3028 rbd_dev->spec->pool_name = kstrdup(name, GFP_KERNEL);
3029 if (!rbd_dev->spec->pool_name)
3032 /* Fetch the image name; tolerate failure here */
3034 name = rbd_dev_image_name(rbd_dev);
3036 rbd_dev->spec->image_name = (char *) name;
3038 rbd_warn(rbd_dev, "unable to get image name");
3040 /* Look up the snapshot name. */
3042 name = rbd_snap_name(rbd_dev, rbd_dev->spec->snap_id);
3044 rbd_warn(rbd_dev, "no snapshot with id %llu",
3045 rbd_dev->spec->snap_id); /* Really a BUG() */
3049 rbd_dev->spec->snap_name = kstrdup(name, GFP_KERNEL);
3050 if(!rbd_dev->spec->snap_name)
3056 kfree(rbd_dev->spec->pool_name);
3057 rbd_dev->spec->pool_name = NULL;
3062 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev, u64 *ver)
3071 struct ceph_snap_context *snapc;
3075 * We'll need room for the seq value (maximum snapshot id),
3076 * snapshot count, and array of that many snapshot ids.
3077 * For now we have a fixed upper limit on the number we're
3078 * prepared to receive.
3080 size = sizeof (__le64) + sizeof (__le32) +
3081 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3082 reply_buf = kzalloc(size, GFP_KERNEL);
3086 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3087 "rbd", "get_snapcontext",
3089 reply_buf, size, ver);
3090 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3096 end = (char *) reply_buf + size;
3097 ceph_decode_64_safe(&p, end, seq, out);
3098 ceph_decode_32_safe(&p, end, snap_count, out);
3101 * Make sure the reported number of snapshot ids wouldn't go
3102 * beyond the end of our buffer. But before checking that,
3103 * make sure the computed size of the snapshot context we
3104 * allocate is representable in a size_t.
3106 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
3111 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
3114 size = sizeof (struct ceph_snap_context) +
3115 snap_count * sizeof (snapc->snaps[0]);
3116 snapc = kmalloc(size, GFP_KERNEL);
3122 atomic_set(&snapc->nref, 1);
3124 snapc->num_snaps = snap_count;
3125 for (i = 0; i < snap_count; i++)
3126 snapc->snaps[i] = ceph_decode_64(&p);
3128 rbd_dev->header.snapc = snapc;
3130 dout(" snap context seq = %llu, snap_count = %u\n",
3131 (unsigned long long) seq, (unsigned int) snap_count);
3139 static char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)
3149 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
3150 reply_buf = kmalloc(size, GFP_KERNEL);
3152 return ERR_PTR(-ENOMEM);
3154 snap_id = cpu_to_le64(rbd_dev->header.snapc->snaps[which]);
3155 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3156 "rbd", "get_snapshot_name",
3157 (char *) &snap_id, sizeof (snap_id),
3158 reply_buf, size, NULL);
3159 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3164 end = (char *) reply_buf + size;
3165 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3166 if (IS_ERR(snap_name)) {
3167 ret = PTR_ERR(snap_name);
3170 dout(" snap_id 0x%016llx snap_name = %s\n",
3171 (unsigned long long) le64_to_cpu(snap_id), snap_name);
3179 return ERR_PTR(ret);
3182 static char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,
3183 u64 *snap_size, u64 *snap_features)
3189 snap_id = rbd_dev->header.snapc->snaps[which];
3190 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, &order, snap_size);
3192 return ERR_PTR(ret);
3193 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, snap_features);
3195 return ERR_PTR(ret);
3197 return rbd_dev_v2_snap_name(rbd_dev, which);
3200 static char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,
3201 u64 *snap_size, u64 *snap_features)
3203 if (rbd_dev->image_format == 1)
3204 return rbd_dev_v1_snap_info(rbd_dev, which,
3205 snap_size, snap_features);
3206 if (rbd_dev->image_format == 2)
3207 return rbd_dev_v2_snap_info(rbd_dev, which,
3208 snap_size, snap_features);
3209 return ERR_PTR(-EINVAL);
3212 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver)
3217 down_write(&rbd_dev->header_rwsem);
3219 /* Grab old order first, to see if it changes */
3221 obj_order = rbd_dev->header.obj_order,
3222 ret = rbd_dev_v2_image_size(rbd_dev);
3225 if (rbd_dev->header.obj_order != obj_order) {
3229 rbd_update_mapping_size(rbd_dev);
3231 ret = rbd_dev_v2_snap_context(rbd_dev, hver);
3232 dout("rbd_dev_v2_snap_context returned %d\n", ret);
3235 ret = rbd_dev_snaps_update(rbd_dev);
3236 dout("rbd_dev_snaps_update returned %d\n", ret);
3239 ret = rbd_dev_snaps_register(rbd_dev);
3240 dout("rbd_dev_snaps_register returned %d\n", ret);
3242 up_write(&rbd_dev->header_rwsem);
3248 * Scan the rbd device's current snapshot list and compare it to the
3249 * newly-received snapshot context. Remove any existing snapshots
3250 * not present in the new snapshot context. Add a new snapshot for
3251 * any snaphots in the snapshot context not in the current list.
3252 * And verify there are no changes to snapshots we already know
3255 * Assumes the snapshots in the snapshot context are sorted by
3256 * snapshot id, highest id first. (Snapshots in the rbd_dev's list
3257 * are also maintained in that order.)
3259 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
3261 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3262 const u32 snap_count = snapc->num_snaps;
3263 struct list_head *head = &rbd_dev->snaps;
3264 struct list_head *links = head->next;
3267 dout("%s: snap count is %u\n", __func__, (unsigned int) snap_count);
3268 while (index < snap_count || links != head) {
3270 struct rbd_snap *snap;
3273 u64 snap_features = 0;
3275 snap_id = index < snap_count ? snapc->snaps[index]
3277 snap = links != head ? list_entry(links, struct rbd_snap, node)
3279 rbd_assert(!snap || snap->id != CEPH_NOSNAP);
3281 if (snap_id == CEPH_NOSNAP || (snap && snap->id > snap_id)) {
3282 struct list_head *next = links->next;
3285 * A previously-existing snapshot is not in
3286 * the new snap context.
3288 * If the now missing snapshot is the one the
3289 * image is mapped to, clear its exists flag
3290 * so we can avoid sending any more requests
3293 if (rbd_dev->spec->snap_id == snap->id)
3294 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3295 rbd_remove_snap_dev(snap);
3296 dout("%ssnap id %llu has been removed\n",
3297 rbd_dev->spec->snap_id == snap->id ?
3299 (unsigned long long) snap->id);
3301 /* Done with this list entry; advance */
3307 snap_name = rbd_dev_snap_info(rbd_dev, index,
3308 &snap_size, &snap_features);
3309 if (IS_ERR(snap_name))
3310 return PTR_ERR(snap_name);
3312 dout("entry %u: snap_id = %llu\n", (unsigned int) snap_count,
3313 (unsigned long long) snap_id);
3314 if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) {
3315 struct rbd_snap *new_snap;
3317 /* We haven't seen this snapshot before */
3319 new_snap = __rbd_add_snap_dev(rbd_dev, snap_name,
3320 snap_id, snap_size, snap_features);
3321 if (IS_ERR(new_snap)) {
3322 int err = PTR_ERR(new_snap);
3324 dout(" failed to add dev, error %d\n", err);
3329 /* New goes before existing, or at end of list */
3331 dout(" added dev%s\n", snap ? "" : " at end\n");
3333 list_add_tail(&new_snap->node, &snap->node);
3335 list_add_tail(&new_snap->node, head);
3337 /* Already have this one */
3339 dout(" already present\n");
3341 rbd_assert(snap->size == snap_size);
3342 rbd_assert(!strcmp(snap->name, snap_name));
3343 rbd_assert(snap->features == snap_features);
3345 /* Done with this list entry; advance */
3347 links = links->next;
3350 /* Advance to the next entry in the snapshot context */
3354 dout("%s: done\n", __func__);
3360 * Scan the list of snapshots and register the devices for any that
3361 * have not already been registered.
3363 static int rbd_dev_snaps_register(struct rbd_device *rbd_dev)
3365 struct rbd_snap *snap;
3368 dout("%s:\n", __func__);
3369 if (WARN_ON(!device_is_registered(&rbd_dev->dev)))
3372 list_for_each_entry(snap, &rbd_dev->snaps, node) {
3373 if (!rbd_snap_registered(snap)) {
3374 ret = rbd_register_snap_dev(snap, &rbd_dev->dev);
3379 dout("%s: returning %d\n", __func__, ret);
3384 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
3389 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3391 dev = &rbd_dev->dev;
3392 dev->bus = &rbd_bus_type;
3393 dev->type = &rbd_device_type;
3394 dev->parent = &rbd_root_dev;
3395 dev->release = rbd_dev_release;
3396 dev_set_name(dev, "%d", rbd_dev->dev_id);
3397 ret = device_register(dev);
3399 mutex_unlock(&ctl_mutex);
3404 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
3406 device_unregister(&rbd_dev->dev);
3409 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
3412 * Get a unique rbd identifier for the given new rbd_dev, and add
3413 * the rbd_dev to the global list. The minimum rbd id is 1.
3415 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
3417 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
3419 spin_lock(&rbd_dev_list_lock);
3420 list_add_tail(&rbd_dev->node, &rbd_dev_list);
3421 spin_unlock(&rbd_dev_list_lock);
3422 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
3423 (unsigned long long) rbd_dev->dev_id);
3427 * Remove an rbd_dev from the global list, and record that its
3428 * identifier is no longer in use.
3430 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
3432 struct list_head *tmp;
3433 int rbd_id = rbd_dev->dev_id;
3436 rbd_assert(rbd_id > 0);
3438 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
3439 (unsigned long long) rbd_dev->dev_id);
3440 spin_lock(&rbd_dev_list_lock);
3441 list_del_init(&rbd_dev->node);
3444 * If the id being "put" is not the current maximum, there
3445 * is nothing special we need to do.
3447 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
3448 spin_unlock(&rbd_dev_list_lock);
3453 * We need to update the current maximum id. Search the
3454 * list to find out what it is. We're more likely to find
3455 * the maximum at the end, so search the list backward.
3458 list_for_each_prev(tmp, &rbd_dev_list) {
3459 struct rbd_device *rbd_dev;
3461 rbd_dev = list_entry(tmp, struct rbd_device, node);
3462 if (rbd_dev->dev_id > max_id)
3463 max_id = rbd_dev->dev_id;
3465 spin_unlock(&rbd_dev_list_lock);
3468 * The max id could have been updated by rbd_dev_id_get(), in
3469 * which case it now accurately reflects the new maximum.
3470 * Be careful not to overwrite the maximum value in that
3473 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
3474 dout(" max dev id has been reset\n");
3478 * Skips over white space at *buf, and updates *buf to point to the
3479 * first found non-space character (if any). Returns the length of
3480 * the token (string of non-white space characters) found. Note
3481 * that *buf must be terminated with '\0'.
3483 static inline size_t next_token(const char **buf)
3486 * These are the characters that produce nonzero for
3487 * isspace() in the "C" and "POSIX" locales.
3489 const char *spaces = " \f\n\r\t\v";
3491 *buf += strspn(*buf, spaces); /* Find start of token */
3493 return strcspn(*buf, spaces); /* Return token length */
3497 * Finds the next token in *buf, and if the provided token buffer is
3498 * big enough, copies the found token into it. The result, if
3499 * copied, is guaranteed to be terminated with '\0'. Note that *buf
3500 * must be terminated with '\0' on entry.
3502 * Returns the length of the token found (not including the '\0').
3503 * Return value will be 0 if no token is found, and it will be >=
3504 * token_size if the token would not fit.
3506 * The *buf pointer will be updated to point beyond the end of the
3507 * found token. Note that this occurs even if the token buffer is
3508 * too small to hold it.
3510 static inline size_t copy_token(const char **buf,
3516 len = next_token(buf);
3517 if (len < token_size) {
3518 memcpy(token, *buf, len);
3519 *(token + len) = '\0';
3527 * Finds the next token in *buf, dynamically allocates a buffer big
3528 * enough to hold a copy of it, and copies the token into the new
3529 * buffer. The copy is guaranteed to be terminated with '\0'. Note
3530 * that a duplicate buffer is created even for a zero-length token.
3532 * Returns a pointer to the newly-allocated duplicate, or a null
3533 * pointer if memory for the duplicate was not available. If
3534 * the lenp argument is a non-null pointer, the length of the token
3535 * (not including the '\0') is returned in *lenp.
3537 * If successful, the *buf pointer will be updated to point beyond
3538 * the end of the found token.
3540 * Note: uses GFP_KERNEL for allocation.
3542 static inline char *dup_token(const char **buf, size_t *lenp)
3547 len = next_token(buf);
3548 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
3551 *(dup + len) = '\0';
3561 * Parse the options provided for an "rbd add" (i.e., rbd image
3562 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
3563 * and the data written is passed here via a NUL-terminated buffer.
3564 * Returns 0 if successful or an error code otherwise.
3566 * The information extracted from these options is recorded in
3567 * the other parameters which return dynamically-allocated
3570 * The address of a pointer that will refer to a ceph options
3571 * structure. Caller must release the returned pointer using
3572 * ceph_destroy_options() when it is no longer needed.
3574 * Address of an rbd options pointer. Fully initialized by
3575 * this function; caller must release with kfree().
3577 * Address of an rbd image specification pointer. Fully
3578 * initialized by this function based on parsed options.
3579 * Caller must release with rbd_spec_put().
3581 * The options passed take this form:
3582 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
3585 * A comma-separated list of one or more monitor addresses.
3586 * A monitor address is an ip address, optionally followed
3587 * by a port number (separated by a colon).
3588 * I.e.: ip1[:port1][,ip2[:port2]...]
3590 * A comma-separated list of ceph and/or rbd options.
3592 * The name of the rados pool containing the rbd image.
3594 * The name of the image in that pool to map.
3596 * An optional snapshot id. If provided, the mapping will
3597 * present data from the image at the time that snapshot was
3598 * created. The image head is used if no snapshot id is
3599 * provided. Snapshot mappings are always read-only.
3601 static int rbd_add_parse_args(const char *buf,
3602 struct ceph_options **ceph_opts,
3603 struct rbd_options **opts,
3604 struct rbd_spec **rbd_spec)
3608 const char *mon_addrs;
3609 size_t mon_addrs_size;
3610 struct rbd_spec *spec = NULL;
3611 struct rbd_options *rbd_opts = NULL;
3612 struct ceph_options *copts;
3615 /* The first four tokens are required */
3617 len = next_token(&buf);
3619 rbd_warn(NULL, "no monitor address(es) provided");
3623 mon_addrs_size = len + 1;
3627 options = dup_token(&buf, NULL);
3631 rbd_warn(NULL, "no options provided");
3635 spec = rbd_spec_alloc();
3639 spec->pool_name = dup_token(&buf, NULL);
3640 if (!spec->pool_name)
3642 if (!*spec->pool_name) {
3643 rbd_warn(NULL, "no pool name provided");
3647 spec->image_name = dup_token(&buf, NULL);
3648 if (!spec->image_name)
3650 if (!*spec->image_name) {
3651 rbd_warn(NULL, "no image name provided");
3656 * Snapshot name is optional; default is to use "-"
3657 * (indicating the head/no snapshot).
3659 len = next_token(&buf);
3661 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
3662 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
3663 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
3664 ret = -ENAMETOOLONG;
3667 spec->snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
3668 if (!spec->snap_name)
3670 *(spec->snap_name + len) = '\0';
3672 /* Initialize all rbd options to the defaults */
3674 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
3678 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
3680 copts = ceph_parse_options(options, mon_addrs,
3681 mon_addrs + mon_addrs_size - 1,
3682 parse_rbd_opts_token, rbd_opts);
3683 if (IS_ERR(copts)) {
3684 ret = PTR_ERR(copts);
3705 * An rbd format 2 image has a unique identifier, distinct from the
3706 * name given to it by the user. Internally, that identifier is
3707 * what's used to specify the names of objects related to the image.
3709 * A special "rbd id" object is used to map an rbd image name to its
3710 * id. If that object doesn't exist, then there is no v2 rbd image
3711 * with the supplied name.
3713 * This function will record the given rbd_dev's image_id field if
3714 * it can be determined, and in that case will return 0. If any
3715 * errors occur a negative errno will be returned and the rbd_dev's
3716 * image_id field will be unchanged (and should be NULL).
3718 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
3727 * When probing a parent image, the image id is already
3728 * known (and the image name likely is not). There's no
3729 * need to fetch the image id again in this case.
3731 if (rbd_dev->spec->image_id)
3735 * First, see if the format 2 image id file exists, and if
3736 * so, get the image's persistent id from it.
3738 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
3739 object_name = kmalloc(size, GFP_NOIO);
3742 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
3743 dout("rbd id object name is %s\n", object_name);
3745 /* Response will be an encoded string, which includes a length */
3747 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
3748 response = kzalloc(size, GFP_NOIO);
3754 ret = rbd_obj_method_sync(rbd_dev, object_name,
3757 response, RBD_IMAGE_ID_LEN_MAX, NULL);
3758 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3763 rbd_dev->spec->image_id = ceph_extract_encoded_string(&p,
3764 p + RBD_IMAGE_ID_LEN_MAX,
3766 if (IS_ERR(rbd_dev->spec->image_id)) {
3767 ret = PTR_ERR(rbd_dev->spec->image_id);
3768 rbd_dev->spec->image_id = NULL;
3770 dout("image_id is %s\n", rbd_dev->spec->image_id);
3779 static int rbd_dev_v1_probe(struct rbd_device *rbd_dev)
3784 /* Version 1 images have no id; empty string is used */
3786 rbd_dev->spec->image_id = kstrdup("", GFP_KERNEL);
3787 if (!rbd_dev->spec->image_id)
3790 /* Record the header object name for this rbd image. */
3792 size = strlen(rbd_dev->spec->image_name) + sizeof (RBD_SUFFIX);
3793 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
3794 if (!rbd_dev->header_name) {
3798 sprintf(rbd_dev->header_name, "%s%s",
3799 rbd_dev->spec->image_name, RBD_SUFFIX);
3801 /* Populate rbd image metadata */
3803 ret = rbd_read_header(rbd_dev, &rbd_dev->header);
3807 /* Version 1 images have no parent (no layering) */
3809 rbd_dev->parent_spec = NULL;
3810 rbd_dev->parent_overlap = 0;
3812 rbd_dev->image_format = 1;
3814 dout("discovered version 1 image, header name is %s\n",
3815 rbd_dev->header_name);
3820 kfree(rbd_dev->header_name);
3821 rbd_dev->header_name = NULL;
3822 kfree(rbd_dev->spec->image_id);
3823 rbd_dev->spec->image_id = NULL;
3828 static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
3835 * Image id was filled in by the caller. Record the header
3836 * object name for this rbd image.
3838 size = sizeof (RBD_HEADER_PREFIX) + strlen(rbd_dev->spec->image_id);
3839 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
3840 if (!rbd_dev->header_name)
3842 sprintf(rbd_dev->header_name, "%s%s",
3843 RBD_HEADER_PREFIX, rbd_dev->spec->image_id);
3845 /* Get the size and object order for the image */
3847 ret = rbd_dev_v2_image_size(rbd_dev);
3851 /* Get the object prefix (a.k.a. block_name) for the image */
3853 ret = rbd_dev_v2_object_prefix(rbd_dev);
3857 /* Get the and check features for the image */
3859 ret = rbd_dev_v2_features(rbd_dev);
3863 /* If the image supports layering, get the parent info */
3865 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
3866 ret = rbd_dev_v2_parent_info(rbd_dev);
3871 /* crypto and compression type aren't (yet) supported for v2 images */
3873 rbd_dev->header.crypt_type = 0;
3874 rbd_dev->header.comp_type = 0;
3876 /* Get the snapshot context, plus the header version */
3878 ret = rbd_dev_v2_snap_context(rbd_dev, &ver);
3881 rbd_dev->header.obj_version = ver;
3883 rbd_dev->image_format = 2;
3885 dout("discovered version 2 image, header name is %s\n",
3886 rbd_dev->header_name);
3890 rbd_dev->parent_overlap = 0;
3891 rbd_spec_put(rbd_dev->parent_spec);
3892 rbd_dev->parent_spec = NULL;
3893 kfree(rbd_dev->header_name);
3894 rbd_dev->header_name = NULL;
3895 kfree(rbd_dev->header.object_prefix);
3896 rbd_dev->header.object_prefix = NULL;
3901 static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
3905 /* no need to lock here, as rbd_dev is not registered yet */
3906 ret = rbd_dev_snaps_update(rbd_dev);
3910 ret = rbd_dev_probe_update_spec(rbd_dev);
3914 ret = rbd_dev_set_mapping(rbd_dev);
3918 /* generate unique id: find highest unique id, add one */
3919 rbd_dev_id_get(rbd_dev);
3921 /* Fill in the device name, now that we have its id. */
3922 BUILD_BUG_ON(DEV_NAME_LEN
3923 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
3924 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
3926 /* Get our block major device number. */
3928 ret = register_blkdev(0, rbd_dev->name);
3931 rbd_dev->major = ret;
3933 /* Set up the blkdev mapping. */
3935 ret = rbd_init_disk(rbd_dev);
3937 goto err_out_blkdev;
3939 ret = rbd_bus_add_dev(rbd_dev);
3944 * At this point cleanup in the event of an error is the job
3945 * of the sysfs code (initiated by rbd_bus_del_dev()).
3947 down_write(&rbd_dev->header_rwsem);
3948 ret = rbd_dev_snaps_register(rbd_dev);
3949 up_write(&rbd_dev->header_rwsem);
3953 ret = rbd_dev_header_watch_sync(rbd_dev, 1);
3957 /* Everything's ready. Announce the disk to the world. */
3959 add_disk(rbd_dev->disk);
3961 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
3962 (unsigned long long) rbd_dev->mapping.size);
3966 /* this will also clean up rest of rbd_dev stuff */
3968 rbd_bus_del_dev(rbd_dev);
3972 rbd_free_disk(rbd_dev);
3974 unregister_blkdev(rbd_dev->major, rbd_dev->name);
3976 rbd_dev_id_put(rbd_dev);
3978 rbd_remove_all_snaps(rbd_dev);
3984 * Probe for the existence of the header object for the given rbd
3985 * device. For format 2 images this includes determining the image
3988 static int rbd_dev_probe(struct rbd_device *rbd_dev)
3993 * Get the id from the image id object. If it's not a
3994 * format 2 image, we'll get ENOENT back, and we'll assume
3995 * it's a format 1 image.
3997 ret = rbd_dev_image_id(rbd_dev);
3999 ret = rbd_dev_v1_probe(rbd_dev);
4001 ret = rbd_dev_v2_probe(rbd_dev);
4003 dout("probe failed, returning %d\n", ret);
4008 ret = rbd_dev_probe_finish(rbd_dev);
4010 rbd_header_free(&rbd_dev->header);
4015 static ssize_t rbd_add(struct bus_type *bus,
4019 struct rbd_device *rbd_dev = NULL;
4020 struct ceph_options *ceph_opts = NULL;
4021 struct rbd_options *rbd_opts = NULL;
4022 struct rbd_spec *spec = NULL;
4023 struct rbd_client *rbdc;
4024 struct ceph_osd_client *osdc;
4027 if (!try_module_get(THIS_MODULE))
4030 /* parse add command */
4031 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4033 goto err_out_module;
4035 rbdc = rbd_get_client(ceph_opts);
4040 ceph_opts = NULL; /* rbd_dev client now owns this */
4043 osdc = &rbdc->client->osdc;
4044 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4046 goto err_out_client;
4047 spec->pool_id = (u64) rc;
4049 /* The ceph file layout needs to fit pool id in 32 bits */
4051 if (WARN_ON(spec->pool_id > (u64) U32_MAX)) {
4053 goto err_out_client;
4056 rbd_dev = rbd_dev_create(rbdc, spec);
4058 goto err_out_client;
4059 rbdc = NULL; /* rbd_dev now owns this */
4060 spec = NULL; /* rbd_dev now owns this */
4062 rbd_dev->mapping.read_only = rbd_opts->read_only;
4064 rbd_opts = NULL; /* done with this */
4066 rc = rbd_dev_probe(rbd_dev);
4068 goto err_out_rbd_dev;
4072 rbd_dev_destroy(rbd_dev);
4074 rbd_put_client(rbdc);
4077 ceph_destroy_options(ceph_opts);
4081 module_put(THIS_MODULE);
4083 dout("Error adding device %s\n", buf);
4085 return (ssize_t) rc;
4088 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4090 struct list_head *tmp;
4091 struct rbd_device *rbd_dev;
4093 spin_lock(&rbd_dev_list_lock);
4094 list_for_each(tmp, &rbd_dev_list) {
4095 rbd_dev = list_entry(tmp, struct rbd_device, node);
4096 if (rbd_dev->dev_id == dev_id) {
4097 spin_unlock(&rbd_dev_list_lock);
4101 spin_unlock(&rbd_dev_list_lock);
4105 static void rbd_dev_release(struct device *dev)
4107 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4109 if (rbd_dev->watch_event)
4110 rbd_dev_header_watch_sync(rbd_dev, 0);
4112 /* clean up and free blkdev */
4113 rbd_free_disk(rbd_dev);
4114 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4116 /* release allocated disk header fields */
4117 rbd_header_free(&rbd_dev->header);
4119 /* done with the id, and with the rbd_dev */
4120 rbd_dev_id_put(rbd_dev);
4121 rbd_assert(rbd_dev->rbd_client != NULL);
4122 rbd_dev_destroy(rbd_dev);
4124 /* release module ref */
4125 module_put(THIS_MODULE);
4128 static ssize_t rbd_remove(struct bus_type *bus,
4132 struct rbd_device *rbd_dev = NULL;
4137 rc = strict_strtoul(buf, 10, &ul);
4141 /* convert to int; abort if we lost anything in the conversion */
4142 target_id = (int) ul;
4143 if (target_id != ul)
4146 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4148 rbd_dev = __rbd_get_dev(target_id);
4154 spin_lock_irq(&rbd_dev->lock);
4155 if (rbd_dev->open_count)
4158 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
4159 spin_unlock_irq(&rbd_dev->lock);
4163 rbd_remove_all_snaps(rbd_dev);
4164 rbd_bus_del_dev(rbd_dev);
4167 mutex_unlock(&ctl_mutex);
4173 * create control files in sysfs
4176 static int rbd_sysfs_init(void)
4180 ret = device_register(&rbd_root_dev);
4184 ret = bus_register(&rbd_bus_type);
4186 device_unregister(&rbd_root_dev);
4191 static void rbd_sysfs_cleanup(void)
4193 bus_unregister(&rbd_bus_type);
4194 device_unregister(&rbd_root_dev);
4197 static int __init rbd_init(void)
4201 if (!libceph_compatible(NULL)) {
4202 rbd_warn(NULL, "libceph incompatibility (quitting)");
4206 rc = rbd_sysfs_init();
4209 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
4213 static void __exit rbd_exit(void)
4215 rbd_sysfs_cleanup();
4218 module_init(rbd_init);
4219 module_exit(rbd_exit);
4221 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
4222 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
4223 MODULE_DESCRIPTION("rados block device");
4225 /* following authorship retained from original osdblk.c */
4226 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
4228 MODULE_LICENSE("GPL");