3 rbd.c -- Export ceph rados objects as a Linux block device
6 based on drivers/block/osdblk.c:
8 Copyright 2009 Red Hat, Inc.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; see the file COPYING. If not, write to
21 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25 For usage instructions, please refer to:
27 Documentation/ABI/testing/sysfs-bus-rbd
31 #include <linux/ceph/libceph.h>
32 #include <linux/ceph/osd_client.h>
33 #include <linux/ceph/mon_client.h>
34 #include <linux/ceph/decode.h>
35 #include <linux/parser.h>
36 #include <linux/bsearch.h>
38 #include <linux/kernel.h>
39 #include <linux/device.h>
40 #include <linux/module.h>
42 #include <linux/blkdev.h>
43 #include <linux/slab.h>
45 #include "rbd_types.h"
47 #define RBD_DEBUG /* Activate rbd_assert() calls */
50 * The basic unit of block I/O is a sector. It is interpreted in a
51 * number of contexts in Linux (blk, bio, genhd), but the default is
52 * universally 512 bytes. These symbols are just slightly more
53 * meaningful than the bare numbers they represent.
55 #define SECTOR_SHIFT 9
56 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT)
58 #define RBD_DRV_NAME "rbd"
59 #define RBD_DRV_NAME_LONG "rbd (rados block device)"
61 #define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
63 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
64 #define RBD_MAX_SNAP_NAME_LEN \
65 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
67 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
69 #define RBD_SNAP_HEAD_NAME "-"
71 #define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
73 /* This allows a single page to hold an image name sent by OSD */
74 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
75 #define RBD_IMAGE_ID_LEN_MAX 64
77 #define RBD_OBJ_PREFIX_LEN_MAX 64
81 #define RBD_FEATURE_LAYERING (1<<0)
82 #define RBD_FEATURE_STRIPINGV2 (1<<1)
83 #define RBD_FEATURES_ALL \
84 (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
86 /* Features supported by this (client software) implementation. */
88 #define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
91 * An RBD device name will be "rbd#", where the "rbd" comes from
92 * RBD_DRV_NAME above, and # is a unique integer identifier.
93 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
94 * enough to hold all possible device names.
96 #define DEV_NAME_LEN 32
97 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
100 * block device image metadata (in-memory version)
102 struct rbd_image_header {
103 /* These four fields never change for a given rbd image */
110 /* The remaining fields need to be updated occasionally */
112 struct ceph_snap_context *snapc;
121 * An rbd image specification.
123 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
124 * identify an image. Each rbd_dev structure includes a pointer to
125 * an rbd_spec structure that encapsulates this identity.
127 * Each of the id's in an rbd_spec has an associated name. For a
128 * user-mapped image, the names are supplied and the id's associated
129 * with them are looked up. For a layered image, a parent image is
130 * defined by the tuple, and the names are looked up.
132 * An rbd_dev structure contains a parent_spec pointer which is
133 * non-null if the image it represents is a child in a layered
134 * image. This pointer will refer to the rbd_spec structure used
135 * by the parent rbd_dev for its own identity (i.e., the structure
136 * is shared between the parent and child).
138 * Since these structures are populated once, during the discovery
139 * phase of image construction, they are effectively immutable so
140 * we make no effort to synchronize access to them.
142 * Note that code herein does not assume the image name is known (it
143 * could be a null pointer).
147 const char *pool_name;
149 const char *image_id;
150 const char *image_name;
153 const char *snap_name;
159 * an instance of the client. multiple devices may share an rbd client.
162 struct ceph_client *client;
164 struct list_head node;
167 struct rbd_img_request;
168 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
170 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
172 struct rbd_obj_request;
173 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
175 enum obj_request_type {
176 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
180 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
181 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
182 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
183 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
186 struct rbd_obj_request {
187 const char *object_name;
188 u64 offset; /* object start byte */
189 u64 length; /* bytes from offset */
193 * An object request associated with an image will have its
194 * img_data flag set; a standalone object request will not.
196 * A standalone object request will have which == BAD_WHICH
197 * and a null obj_request pointer.
199 * An object request initiated in support of a layered image
200 * object (to check for its existence before a write) will
201 * have which == BAD_WHICH and a non-null obj_request pointer.
203 * Finally, an object request for rbd image data will have
204 * which != BAD_WHICH, and will have a non-null img_request
205 * pointer. The value of which will be in the range
206 * 0..(img_request->obj_request_count-1).
209 struct rbd_obj_request *obj_request; /* STAT op */
211 struct rbd_img_request *img_request;
213 /* links for img_request->obj_requests list */
214 struct list_head links;
217 u32 which; /* posn image request list */
219 enum obj_request_type type;
221 struct bio *bio_list;
227 struct page **copyup_pages;
229 struct ceph_osd_request *osd_req;
231 u64 xferred; /* bytes transferred */
234 rbd_obj_callback_t callback;
235 struct completion completion;
241 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
242 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
243 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
246 struct rbd_img_request {
247 struct rbd_device *rbd_dev;
248 u64 offset; /* starting image byte offset */
249 u64 length; /* byte count from offset */
252 u64 snap_id; /* for reads */
253 struct ceph_snap_context *snapc; /* for writes */
256 struct request *rq; /* block request */
257 struct rbd_obj_request *obj_request; /* obj req initiator */
259 struct page **copyup_pages;
260 spinlock_t completion_lock;/* protects next_completion */
262 rbd_img_callback_t callback;
263 u64 xferred;/* aggregate bytes transferred */
264 int result; /* first nonzero obj_request result */
266 u32 obj_request_count;
267 struct list_head obj_requests; /* rbd_obj_request structs */
272 #define for_each_obj_request(ireq, oreq) \
273 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
274 #define for_each_obj_request_from(ireq, oreq) \
275 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
276 #define for_each_obj_request_safe(ireq, oreq, n) \
277 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
289 int dev_id; /* blkdev unique id */
291 int major; /* blkdev assigned major */
292 struct gendisk *disk; /* blkdev's gendisk and rq */
294 u32 image_format; /* Either 1 or 2 */
295 struct rbd_client *rbd_client;
297 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
299 spinlock_t lock; /* queue, flags, open_count */
301 struct rbd_image_header header;
302 unsigned long flags; /* possibly lock protected */
303 struct rbd_spec *spec;
307 struct ceph_file_layout layout;
309 struct ceph_osd_event *watch_event;
310 struct rbd_obj_request *watch_request;
312 struct rbd_spec *parent_spec;
314 struct rbd_device *parent;
316 /* protects updating the header */
317 struct rw_semaphore header_rwsem;
319 struct rbd_mapping mapping;
321 struct list_head node;
325 unsigned long open_count; /* protected by lock */
329 * Flag bits for rbd_dev->flags. If atomicity is required,
330 * rbd_dev->lock is used to protect access.
332 * Currently, only the "removing" flag (which is coupled with the
333 * "open_count" field) requires atomic access.
336 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
337 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
340 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
342 static LIST_HEAD(rbd_dev_list); /* devices */
343 static DEFINE_SPINLOCK(rbd_dev_list_lock);
345 static LIST_HEAD(rbd_client_list); /* clients */
346 static DEFINE_SPINLOCK(rbd_client_list_lock);
348 static struct kmem_cache *rbd_img_request_cache;
349 static struct kmem_cache *rbd_obj_request_cache;
351 static int rbd_img_request_submit(struct rbd_img_request *img_request);
353 static void rbd_dev_device_release(struct device *dev);
355 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
357 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
359 static int rbd_dev_image_probe(struct rbd_device *rbd_dev);
361 static struct bus_attribute rbd_bus_attrs[] = {
362 __ATTR(add, S_IWUSR, NULL, rbd_add),
363 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
367 static struct bus_type rbd_bus_type = {
369 .bus_attrs = rbd_bus_attrs,
372 static void rbd_root_dev_release(struct device *dev)
376 static struct device rbd_root_dev = {
378 .release = rbd_root_dev_release,
381 static __printf(2, 3)
382 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
384 struct va_format vaf;
392 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
393 else if (rbd_dev->disk)
394 printk(KERN_WARNING "%s: %s: %pV\n",
395 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
396 else if (rbd_dev->spec && rbd_dev->spec->image_name)
397 printk(KERN_WARNING "%s: image %s: %pV\n",
398 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
399 else if (rbd_dev->spec && rbd_dev->spec->image_id)
400 printk(KERN_WARNING "%s: id %s: %pV\n",
401 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
403 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
404 RBD_DRV_NAME, rbd_dev, &vaf);
409 #define rbd_assert(expr) \
410 if (unlikely(!(expr))) { \
411 printk(KERN_ERR "\nAssertion failure in %s() " \
413 "\trbd_assert(%s);\n\n", \
414 __func__, __LINE__, #expr); \
417 #else /* !RBD_DEBUG */
418 # define rbd_assert(expr) ((void) 0)
419 #endif /* !RBD_DEBUG */
421 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
422 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
423 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
425 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
426 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev);
427 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
429 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
430 u8 *order, u64 *snap_size);
431 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
433 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name);
435 static int rbd_open(struct block_device *bdev, fmode_t mode)
437 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
438 bool removing = false;
440 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
443 spin_lock_irq(&rbd_dev->lock);
444 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
447 rbd_dev->open_count++;
448 spin_unlock_irq(&rbd_dev->lock);
452 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
453 (void) get_device(&rbd_dev->dev);
454 set_device_ro(bdev, rbd_dev->mapping.read_only);
455 mutex_unlock(&ctl_mutex);
460 static int rbd_release(struct gendisk *disk, fmode_t mode)
462 struct rbd_device *rbd_dev = disk->private_data;
463 unsigned long open_count_before;
465 spin_lock_irq(&rbd_dev->lock);
466 open_count_before = rbd_dev->open_count--;
467 spin_unlock_irq(&rbd_dev->lock);
468 rbd_assert(open_count_before > 0);
470 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
471 put_device(&rbd_dev->dev);
472 mutex_unlock(&ctl_mutex);
477 static const struct block_device_operations rbd_bd_ops = {
478 .owner = THIS_MODULE,
480 .release = rbd_release,
484 * Initialize an rbd client instance.
487 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
489 struct rbd_client *rbdc;
492 dout("%s:\n", __func__);
493 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
497 kref_init(&rbdc->kref);
498 INIT_LIST_HEAD(&rbdc->node);
500 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
502 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
503 if (IS_ERR(rbdc->client))
505 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
507 ret = ceph_open_session(rbdc->client);
511 spin_lock(&rbd_client_list_lock);
512 list_add_tail(&rbdc->node, &rbd_client_list);
513 spin_unlock(&rbd_client_list_lock);
515 mutex_unlock(&ctl_mutex);
516 dout("%s: rbdc %p\n", __func__, rbdc);
521 ceph_destroy_client(rbdc->client);
523 mutex_unlock(&ctl_mutex);
527 ceph_destroy_options(ceph_opts);
528 dout("%s: error %d\n", __func__, ret);
533 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
535 kref_get(&rbdc->kref);
541 * Find a ceph client with specific addr and configuration. If
542 * found, bump its reference count.
544 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
546 struct rbd_client *client_node;
549 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
552 spin_lock(&rbd_client_list_lock);
553 list_for_each_entry(client_node, &rbd_client_list, node) {
554 if (!ceph_compare_options(ceph_opts, client_node->client)) {
555 __rbd_get_client(client_node);
561 spin_unlock(&rbd_client_list_lock);
563 return found ? client_node : NULL;
573 /* string args above */
576 /* Boolean args above */
580 static match_table_t rbd_opts_tokens = {
582 /* string args above */
583 {Opt_read_only, "read_only"},
584 {Opt_read_only, "ro"}, /* Alternate spelling */
585 {Opt_read_write, "read_write"},
586 {Opt_read_write, "rw"}, /* Alternate spelling */
587 /* Boolean args above */
595 #define RBD_READ_ONLY_DEFAULT false
597 static int parse_rbd_opts_token(char *c, void *private)
599 struct rbd_options *rbd_opts = private;
600 substring_t argstr[MAX_OPT_ARGS];
601 int token, intval, ret;
603 token = match_token(c, rbd_opts_tokens, argstr);
607 if (token < Opt_last_int) {
608 ret = match_int(&argstr[0], &intval);
610 pr_err("bad mount option arg (not int) "
614 dout("got int token %d val %d\n", token, intval);
615 } else if (token > Opt_last_int && token < Opt_last_string) {
616 dout("got string token %d val %s\n", token,
618 } else if (token > Opt_last_string && token < Opt_last_bool) {
619 dout("got Boolean token %d\n", token);
621 dout("got token %d\n", token);
626 rbd_opts->read_only = true;
629 rbd_opts->read_only = false;
639 * Get a ceph client with specific addr and configuration, if one does
640 * not exist create it.
642 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
644 struct rbd_client *rbdc;
646 rbdc = rbd_client_find(ceph_opts);
647 if (rbdc) /* using an existing client */
648 ceph_destroy_options(ceph_opts);
650 rbdc = rbd_client_create(ceph_opts);
656 * Destroy ceph client
658 * Caller must hold rbd_client_list_lock.
660 static void rbd_client_release(struct kref *kref)
662 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
664 dout("%s: rbdc %p\n", __func__, rbdc);
665 spin_lock(&rbd_client_list_lock);
666 list_del(&rbdc->node);
667 spin_unlock(&rbd_client_list_lock);
669 ceph_destroy_client(rbdc->client);
674 * Drop reference to ceph client node. If it's not referenced anymore, release
677 static void rbd_put_client(struct rbd_client *rbdc)
680 kref_put(&rbdc->kref, rbd_client_release);
683 static bool rbd_image_format_valid(u32 image_format)
685 return image_format == 1 || image_format == 2;
688 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
693 /* The header has to start with the magic rbd header text */
694 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
697 /* The bio layer requires at least sector-sized I/O */
699 if (ondisk->options.order < SECTOR_SHIFT)
702 /* If we use u64 in a few spots we may be able to loosen this */
704 if (ondisk->options.order > 8 * sizeof (int) - 1)
708 * The size of a snapshot header has to fit in a size_t, and
709 * that limits the number of snapshots.
711 snap_count = le32_to_cpu(ondisk->snap_count);
712 size = SIZE_MAX - sizeof (struct ceph_snap_context);
713 if (snap_count > size / sizeof (__le64))
717 * Not only that, but the size of the entire the snapshot
718 * header must also be representable in a size_t.
720 size -= snap_count * sizeof (__le64);
721 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
728 * Create a new header structure, translate header format from the on-disk
731 static int rbd_header_from_disk(struct rbd_image_header *header,
732 struct rbd_image_header_ondisk *ondisk)
739 memset(header, 0, sizeof (*header));
741 snap_count = le32_to_cpu(ondisk->snap_count);
743 len = strnlen(ondisk->object_prefix, sizeof (ondisk->object_prefix));
744 header->object_prefix = kmalloc(len + 1, GFP_KERNEL);
745 if (!header->object_prefix)
747 memcpy(header->object_prefix, ondisk->object_prefix, len);
748 header->object_prefix[len] = '\0';
751 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
753 /* Save a copy of the snapshot names */
755 if (snap_names_len > (u64) SIZE_MAX)
757 header->snap_names = kmalloc(snap_names_len, GFP_KERNEL);
758 if (!header->snap_names)
761 * Note that rbd_dev_v1_header_read() guarantees
762 * the ondisk buffer we're working with has
763 * snap_names_len bytes beyond the end of the
764 * snapshot id array, this memcpy() is safe.
766 memcpy(header->snap_names, &ondisk->snaps[snap_count],
769 /* Record each snapshot's size */
771 size = snap_count * sizeof (*header->snap_sizes);
772 header->snap_sizes = kmalloc(size, GFP_KERNEL);
773 if (!header->snap_sizes)
775 for (i = 0; i < snap_count; i++)
776 header->snap_sizes[i] =
777 le64_to_cpu(ondisk->snaps[i].image_size);
779 header->snap_names = NULL;
780 header->snap_sizes = NULL;
783 header->features = 0; /* No features support in v1 images */
784 header->obj_order = ondisk->options.order;
785 header->crypt_type = ondisk->options.crypt_type;
786 header->comp_type = ondisk->options.comp_type;
788 /* Allocate and fill in the snapshot context */
790 header->image_size = le64_to_cpu(ondisk->image_size);
792 header->snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
795 header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
796 for (i = 0; i < snap_count; i++)
797 header->snapc->snaps[i] = le64_to_cpu(ondisk->snaps[i].id);
802 kfree(header->snap_sizes);
803 header->snap_sizes = NULL;
804 kfree(header->snap_names);
805 header->snap_names = NULL;
806 kfree(header->object_prefix);
807 header->object_prefix = NULL;
812 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
814 const char *snap_name;
816 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
818 /* Skip over names until we find the one we are looking for */
820 snap_name = rbd_dev->header.snap_names;
822 snap_name += strlen(snap_name) + 1;
824 return kstrdup(snap_name, GFP_KERNEL);
828 * Snapshot id comparison function for use with qsort()/bsearch().
829 * Note that result is for snapshots in *descending* order.
831 static int snapid_compare_reverse(const void *s1, const void *s2)
833 u64 snap_id1 = *(u64 *)s1;
834 u64 snap_id2 = *(u64 *)s2;
836 if (snap_id1 < snap_id2)
838 return snap_id1 == snap_id2 ? 0 : -1;
842 * Search a snapshot context to see if the given snapshot id is
845 * Returns the position of the snapshot id in the array if it's found,
846 * or BAD_SNAP_INDEX otherwise.
848 * Note: The snapshot array is in kept sorted (by the osd) in
849 * reverse order, highest snapshot id first.
851 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
853 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
856 found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
857 sizeof (snap_id), snapid_compare_reverse);
859 return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
862 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
867 which = rbd_dev_snap_index(rbd_dev, snap_id);
868 if (which == BAD_SNAP_INDEX)
871 return _rbd_dev_v1_snap_name(rbd_dev, which);
874 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
876 if (snap_id == CEPH_NOSNAP)
877 return RBD_SNAP_HEAD_NAME;
879 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
880 if (rbd_dev->image_format == 1)
881 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
883 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
886 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
889 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
890 if (snap_id == CEPH_NOSNAP) {
891 *snap_size = rbd_dev->header.image_size;
892 } else if (rbd_dev->image_format == 1) {
895 which = rbd_dev_snap_index(rbd_dev, snap_id);
896 if (which == BAD_SNAP_INDEX)
899 *snap_size = rbd_dev->header.snap_sizes[which];
904 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
913 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
916 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
917 if (snap_id == CEPH_NOSNAP) {
918 *snap_features = rbd_dev->header.features;
919 } else if (rbd_dev->image_format == 1) {
920 *snap_features = 0; /* No features for format 1 */
925 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
929 *snap_features = features;
934 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
936 const char *snap_name = rbd_dev->spec->snap_name;
942 if (strcmp(snap_name, RBD_SNAP_HEAD_NAME)) {
943 snap_id = rbd_snap_id_by_name(rbd_dev, snap_name);
944 if (snap_id == CEPH_NOSNAP)
947 snap_id = CEPH_NOSNAP;
950 ret = rbd_snap_size(rbd_dev, snap_id, &size);
953 ret = rbd_snap_features(rbd_dev, snap_id, &features);
957 rbd_dev->mapping.size = size;
958 rbd_dev->mapping.features = features;
960 /* If we are mapping a snapshot it must be marked read-only */
962 if (snap_id != CEPH_NOSNAP)
963 rbd_dev->mapping.read_only = true;
968 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
970 rbd_dev->mapping.size = 0;
971 rbd_dev->mapping.features = 0;
972 rbd_dev->mapping.read_only = true;
975 static void rbd_dev_clear_mapping(struct rbd_device *rbd_dev)
977 rbd_dev->mapping.size = 0;
978 rbd_dev->mapping.features = 0;
979 rbd_dev->mapping.read_only = true;
982 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
988 name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
991 segment = offset >> rbd_dev->header.obj_order;
992 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
993 rbd_dev->header.object_prefix, segment);
994 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
995 pr_err("error formatting segment name for #%llu (%d)\n",
1004 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1006 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1008 return offset & (segment_size - 1);
1011 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1012 u64 offset, u64 length)
1014 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1016 offset &= segment_size - 1;
1018 rbd_assert(length <= U64_MAX - offset);
1019 if (offset + length > segment_size)
1020 length = segment_size - offset;
1026 * returns the size of an object in the image
1028 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1030 return 1 << header->obj_order;
1037 static void bio_chain_put(struct bio *chain)
1043 chain = chain->bi_next;
1049 * zeros a bio chain, starting at specific offset
1051 static void zero_bio_chain(struct bio *chain, int start_ofs)
1054 unsigned long flags;
1060 bio_for_each_segment(bv, chain, i) {
1061 if (pos + bv->bv_len > start_ofs) {
1062 int remainder = max(start_ofs - pos, 0);
1063 buf = bvec_kmap_irq(bv, &flags);
1064 memset(buf + remainder, 0,
1065 bv->bv_len - remainder);
1066 bvec_kunmap_irq(buf, &flags);
1071 chain = chain->bi_next;
1076 * similar to zero_bio_chain(), zeros data defined by a page array,
1077 * starting at the given byte offset from the start of the array and
1078 * continuing up to the given end offset. The pages array is
1079 * assumed to be big enough to hold all bytes up to the end.
1081 static void zero_pages(struct page **pages, u64 offset, u64 end)
1083 struct page **page = &pages[offset >> PAGE_SHIFT];
1085 rbd_assert(end > offset);
1086 rbd_assert(end - offset <= (u64)SIZE_MAX);
1087 while (offset < end) {
1090 unsigned long flags;
1093 page_offset = (size_t)(offset & ~PAGE_MASK);
1094 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1095 local_irq_save(flags);
1096 kaddr = kmap_atomic(*page);
1097 memset(kaddr + page_offset, 0, length);
1098 kunmap_atomic(kaddr);
1099 local_irq_restore(flags);
1107 * Clone a portion of a bio, starting at the given byte offset
1108 * and continuing for the number of bytes indicated.
1110 static struct bio *bio_clone_range(struct bio *bio_src,
1111 unsigned int offset,
1119 unsigned short end_idx;
1120 unsigned short vcnt;
1123 /* Handle the easy case for the caller */
1125 if (!offset && len == bio_src->bi_size)
1126 return bio_clone(bio_src, gfpmask);
1128 if (WARN_ON_ONCE(!len))
1130 if (WARN_ON_ONCE(len > bio_src->bi_size))
1132 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1135 /* Find first affected segment... */
1138 __bio_for_each_segment(bv, bio_src, idx, 0) {
1139 if (resid < bv->bv_len)
1141 resid -= bv->bv_len;
1145 /* ...and the last affected segment */
1148 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1149 if (resid <= bv->bv_len)
1151 resid -= bv->bv_len;
1153 vcnt = end_idx - idx + 1;
1155 /* Build the clone */
1157 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1159 return NULL; /* ENOMEM */
1161 bio->bi_bdev = bio_src->bi_bdev;
1162 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1163 bio->bi_rw = bio_src->bi_rw;
1164 bio->bi_flags |= 1 << BIO_CLONED;
1167 * Copy over our part of the bio_vec, then update the first
1168 * and last (or only) entries.
1170 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1171 vcnt * sizeof (struct bio_vec));
1172 bio->bi_io_vec[0].bv_offset += voff;
1174 bio->bi_io_vec[0].bv_len -= voff;
1175 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1177 bio->bi_io_vec[0].bv_len = len;
1180 bio->bi_vcnt = vcnt;
1188 * Clone a portion of a bio chain, starting at the given byte offset
1189 * into the first bio in the source chain and continuing for the
1190 * number of bytes indicated. The result is another bio chain of
1191 * exactly the given length, or a null pointer on error.
1193 * The bio_src and offset parameters are both in-out. On entry they
1194 * refer to the first source bio and the offset into that bio where
1195 * the start of data to be cloned is located.
1197 * On return, bio_src is updated to refer to the bio in the source
1198 * chain that contains first un-cloned byte, and *offset will
1199 * contain the offset of that byte within that bio.
1201 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1202 unsigned int *offset,
1206 struct bio *bi = *bio_src;
1207 unsigned int off = *offset;
1208 struct bio *chain = NULL;
1211 /* Build up a chain of clone bios up to the limit */
1213 if (!bi || off >= bi->bi_size || !len)
1214 return NULL; /* Nothing to clone */
1218 unsigned int bi_size;
1222 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1223 goto out_err; /* EINVAL; ran out of bio's */
1225 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1226 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1228 goto out_err; /* ENOMEM */
1231 end = &bio->bi_next;
1234 if (off == bi->bi_size) {
1245 bio_chain_put(chain);
1251 * The default/initial value for all object request flags is 0. For
1252 * each flag, once its value is set to 1 it is never reset to 0
1255 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1257 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1258 struct rbd_device *rbd_dev;
1260 rbd_dev = obj_request->img_request->rbd_dev;
1261 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1266 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1269 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1272 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1274 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1275 struct rbd_device *rbd_dev = NULL;
1277 if (obj_request_img_data_test(obj_request))
1278 rbd_dev = obj_request->img_request->rbd_dev;
1279 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1284 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1287 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1291 * This sets the KNOWN flag after (possibly) setting the EXISTS
1292 * flag. The latter is set based on the "exists" value provided.
1294 * Note that for our purposes once an object exists it never goes
1295 * away again. It's possible that the response from two existence
1296 * checks are separated by the creation of the target object, and
1297 * the first ("doesn't exist") response arrives *after* the second
1298 * ("does exist"). In that case we ignore the second one.
1300 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1304 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1305 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1309 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1312 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1315 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1318 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1321 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1323 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1324 atomic_read(&obj_request->kref.refcount));
1325 kref_get(&obj_request->kref);
1328 static void rbd_obj_request_destroy(struct kref *kref);
1329 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1331 rbd_assert(obj_request != NULL);
1332 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1333 atomic_read(&obj_request->kref.refcount));
1334 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1337 static void rbd_img_request_get(struct rbd_img_request *img_request)
1339 dout("%s: img %p (was %d)\n", __func__, img_request,
1340 atomic_read(&img_request->kref.refcount));
1341 kref_get(&img_request->kref);
1344 static void rbd_img_request_destroy(struct kref *kref);
1345 static void rbd_img_request_put(struct rbd_img_request *img_request)
1347 rbd_assert(img_request != NULL);
1348 dout("%s: img %p (was %d)\n", __func__, img_request,
1349 atomic_read(&img_request->kref.refcount));
1350 kref_put(&img_request->kref, rbd_img_request_destroy);
1353 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1354 struct rbd_obj_request *obj_request)
1356 rbd_assert(obj_request->img_request == NULL);
1358 /* Image request now owns object's original reference */
1359 obj_request->img_request = img_request;
1360 obj_request->which = img_request->obj_request_count;
1361 rbd_assert(!obj_request_img_data_test(obj_request));
1362 obj_request_img_data_set(obj_request);
1363 rbd_assert(obj_request->which != BAD_WHICH);
1364 img_request->obj_request_count++;
1365 list_add_tail(&obj_request->links, &img_request->obj_requests);
1366 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1367 obj_request->which);
1370 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1371 struct rbd_obj_request *obj_request)
1373 rbd_assert(obj_request->which != BAD_WHICH);
1375 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1376 obj_request->which);
1377 list_del(&obj_request->links);
1378 rbd_assert(img_request->obj_request_count > 0);
1379 img_request->obj_request_count--;
1380 rbd_assert(obj_request->which == img_request->obj_request_count);
1381 obj_request->which = BAD_WHICH;
1382 rbd_assert(obj_request_img_data_test(obj_request));
1383 rbd_assert(obj_request->img_request == img_request);
1384 obj_request->img_request = NULL;
1385 obj_request->callback = NULL;
1386 rbd_obj_request_put(obj_request);
1389 static bool obj_request_type_valid(enum obj_request_type type)
1392 case OBJ_REQUEST_NODATA:
1393 case OBJ_REQUEST_BIO:
1394 case OBJ_REQUEST_PAGES:
1401 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1402 struct rbd_obj_request *obj_request)
1404 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1406 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1409 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1412 dout("%s: img %p\n", __func__, img_request);
1415 * If no error occurred, compute the aggregate transfer
1416 * count for the image request. We could instead use
1417 * atomic64_cmpxchg() to update it as each object request
1418 * completes; not clear which way is better off hand.
1420 if (!img_request->result) {
1421 struct rbd_obj_request *obj_request;
1424 for_each_obj_request(img_request, obj_request)
1425 xferred += obj_request->xferred;
1426 img_request->xferred = xferred;
1429 if (img_request->callback)
1430 img_request->callback(img_request);
1432 rbd_img_request_put(img_request);
1435 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1437 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1439 dout("%s: obj %p\n", __func__, obj_request);
1441 return wait_for_completion_interruptible(&obj_request->completion);
1445 * The default/initial value for all image request flags is 0. Each
1446 * is conditionally set to 1 at image request initialization time
1447 * and currently never change thereafter.
1449 static void img_request_write_set(struct rbd_img_request *img_request)
1451 set_bit(IMG_REQ_WRITE, &img_request->flags);
1455 static bool img_request_write_test(struct rbd_img_request *img_request)
1458 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1461 static void img_request_child_set(struct rbd_img_request *img_request)
1463 set_bit(IMG_REQ_CHILD, &img_request->flags);
1467 static bool img_request_child_test(struct rbd_img_request *img_request)
1470 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1473 static void img_request_layered_set(struct rbd_img_request *img_request)
1475 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1479 static bool img_request_layered_test(struct rbd_img_request *img_request)
1482 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1486 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1488 u64 xferred = obj_request->xferred;
1489 u64 length = obj_request->length;
1491 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1492 obj_request, obj_request->img_request, obj_request->result,
1495 * ENOENT means a hole in the image. We zero-fill the
1496 * entire length of the request. A short read also implies
1497 * zero-fill to the end of the request. Either way we
1498 * update the xferred count to indicate the whole request
1501 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1502 if (obj_request->result == -ENOENT) {
1503 if (obj_request->type == OBJ_REQUEST_BIO)
1504 zero_bio_chain(obj_request->bio_list, 0);
1506 zero_pages(obj_request->pages, 0, length);
1507 obj_request->result = 0;
1508 obj_request->xferred = length;
1509 } else if (xferred < length && !obj_request->result) {
1510 if (obj_request->type == OBJ_REQUEST_BIO)
1511 zero_bio_chain(obj_request->bio_list, xferred);
1513 zero_pages(obj_request->pages, xferred, length);
1514 obj_request->xferred = length;
1516 obj_request_done_set(obj_request);
1519 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1521 dout("%s: obj %p cb %p\n", __func__, obj_request,
1522 obj_request->callback);
1523 if (obj_request->callback)
1524 obj_request->callback(obj_request);
1526 complete_all(&obj_request->completion);
1529 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1531 dout("%s: obj %p\n", __func__, obj_request);
1532 obj_request_done_set(obj_request);
1535 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1537 struct rbd_img_request *img_request = NULL;
1538 struct rbd_device *rbd_dev = NULL;
1539 bool layered = false;
1541 if (obj_request_img_data_test(obj_request)) {
1542 img_request = obj_request->img_request;
1543 layered = img_request && img_request_layered_test(img_request);
1544 rbd_dev = img_request->rbd_dev;
1547 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1548 obj_request, img_request, obj_request->result,
1549 obj_request->xferred, obj_request->length);
1550 if (layered && obj_request->result == -ENOENT &&
1551 obj_request->img_offset < rbd_dev->parent_overlap)
1552 rbd_img_parent_read(obj_request);
1553 else if (img_request)
1554 rbd_img_obj_request_read_callback(obj_request);
1556 obj_request_done_set(obj_request);
1559 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1561 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1562 obj_request->result, obj_request->length);
1564 * There is no such thing as a successful short write. Set
1565 * it to our originally-requested length.
1567 obj_request->xferred = obj_request->length;
1568 obj_request_done_set(obj_request);
1572 * For a simple stat call there's nothing to do. We'll do more if
1573 * this is part of a write sequence for a layered image.
1575 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1577 dout("%s: obj %p\n", __func__, obj_request);
1578 obj_request_done_set(obj_request);
1581 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1582 struct ceph_msg *msg)
1584 struct rbd_obj_request *obj_request = osd_req->r_priv;
1587 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1588 rbd_assert(osd_req == obj_request->osd_req);
1589 if (obj_request_img_data_test(obj_request)) {
1590 rbd_assert(obj_request->img_request);
1591 rbd_assert(obj_request->which != BAD_WHICH);
1593 rbd_assert(obj_request->which == BAD_WHICH);
1596 if (osd_req->r_result < 0)
1597 obj_request->result = osd_req->r_result;
1599 BUG_ON(osd_req->r_num_ops > 2);
1602 * We support a 64-bit length, but ultimately it has to be
1603 * passed to blk_end_request(), which takes an unsigned int.
1605 obj_request->xferred = osd_req->r_reply_op_len[0];
1606 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1607 opcode = osd_req->r_ops[0].op;
1609 case CEPH_OSD_OP_READ:
1610 rbd_osd_read_callback(obj_request);
1612 case CEPH_OSD_OP_WRITE:
1613 rbd_osd_write_callback(obj_request);
1615 case CEPH_OSD_OP_STAT:
1616 rbd_osd_stat_callback(obj_request);
1618 case CEPH_OSD_OP_CALL:
1619 case CEPH_OSD_OP_NOTIFY_ACK:
1620 case CEPH_OSD_OP_WATCH:
1621 rbd_osd_trivial_callback(obj_request);
1624 rbd_warn(NULL, "%s: unsupported op %hu\n",
1625 obj_request->object_name, (unsigned short) opcode);
1629 if (obj_request_done_test(obj_request))
1630 rbd_obj_request_complete(obj_request);
1633 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1635 struct rbd_img_request *img_request = obj_request->img_request;
1636 struct ceph_osd_request *osd_req = obj_request->osd_req;
1639 rbd_assert(osd_req != NULL);
1641 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1642 ceph_osdc_build_request(osd_req, obj_request->offset,
1643 NULL, snap_id, NULL);
1646 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1648 struct rbd_img_request *img_request = obj_request->img_request;
1649 struct ceph_osd_request *osd_req = obj_request->osd_req;
1650 struct ceph_snap_context *snapc;
1651 struct timespec mtime = CURRENT_TIME;
1653 rbd_assert(osd_req != NULL);
1655 snapc = img_request ? img_request->snapc : NULL;
1656 ceph_osdc_build_request(osd_req, obj_request->offset,
1657 snapc, CEPH_NOSNAP, &mtime);
1660 static struct ceph_osd_request *rbd_osd_req_create(
1661 struct rbd_device *rbd_dev,
1663 struct rbd_obj_request *obj_request)
1665 struct ceph_snap_context *snapc = NULL;
1666 struct ceph_osd_client *osdc;
1667 struct ceph_osd_request *osd_req;
1669 if (obj_request_img_data_test(obj_request)) {
1670 struct rbd_img_request *img_request = obj_request->img_request;
1672 rbd_assert(write_request ==
1673 img_request_write_test(img_request));
1675 snapc = img_request->snapc;
1678 /* Allocate and initialize the request, for the single op */
1680 osdc = &rbd_dev->rbd_client->client->osdc;
1681 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1683 return NULL; /* ENOMEM */
1686 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1688 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1690 osd_req->r_callback = rbd_osd_req_callback;
1691 osd_req->r_priv = obj_request;
1693 osd_req->r_oid_len = strlen(obj_request->object_name);
1694 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1695 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1697 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1703 * Create a copyup osd request based on the information in the
1704 * object request supplied. A copyup request has two osd ops,
1705 * a copyup method call, and a "normal" write request.
1707 static struct ceph_osd_request *
1708 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1710 struct rbd_img_request *img_request;
1711 struct ceph_snap_context *snapc;
1712 struct rbd_device *rbd_dev;
1713 struct ceph_osd_client *osdc;
1714 struct ceph_osd_request *osd_req;
1716 rbd_assert(obj_request_img_data_test(obj_request));
1717 img_request = obj_request->img_request;
1718 rbd_assert(img_request);
1719 rbd_assert(img_request_write_test(img_request));
1721 /* Allocate and initialize the request, for the two ops */
1723 snapc = img_request->snapc;
1724 rbd_dev = img_request->rbd_dev;
1725 osdc = &rbd_dev->rbd_client->client->osdc;
1726 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1728 return NULL; /* ENOMEM */
1730 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1731 osd_req->r_callback = rbd_osd_req_callback;
1732 osd_req->r_priv = obj_request;
1734 osd_req->r_oid_len = strlen(obj_request->object_name);
1735 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1736 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1738 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1744 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1746 ceph_osdc_put_request(osd_req);
1749 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1751 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1752 u64 offset, u64 length,
1753 enum obj_request_type type)
1755 struct rbd_obj_request *obj_request;
1759 rbd_assert(obj_request_type_valid(type));
1761 size = strlen(object_name) + 1;
1762 name = kmalloc(size, GFP_KERNEL);
1766 obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
1772 obj_request->object_name = memcpy(name, object_name, size);
1773 obj_request->offset = offset;
1774 obj_request->length = length;
1775 obj_request->flags = 0;
1776 obj_request->which = BAD_WHICH;
1777 obj_request->type = type;
1778 INIT_LIST_HEAD(&obj_request->links);
1779 init_completion(&obj_request->completion);
1780 kref_init(&obj_request->kref);
1782 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1783 offset, length, (int)type, obj_request);
1788 static void rbd_obj_request_destroy(struct kref *kref)
1790 struct rbd_obj_request *obj_request;
1792 obj_request = container_of(kref, struct rbd_obj_request, kref);
1794 dout("%s: obj %p\n", __func__, obj_request);
1796 rbd_assert(obj_request->img_request == NULL);
1797 rbd_assert(obj_request->which == BAD_WHICH);
1799 if (obj_request->osd_req)
1800 rbd_osd_req_destroy(obj_request->osd_req);
1802 rbd_assert(obj_request_type_valid(obj_request->type));
1803 switch (obj_request->type) {
1804 case OBJ_REQUEST_NODATA:
1805 break; /* Nothing to do */
1806 case OBJ_REQUEST_BIO:
1807 if (obj_request->bio_list)
1808 bio_chain_put(obj_request->bio_list);
1810 case OBJ_REQUEST_PAGES:
1811 if (obj_request->pages)
1812 ceph_release_page_vector(obj_request->pages,
1813 obj_request->page_count);
1817 kfree(obj_request->object_name);
1818 obj_request->object_name = NULL;
1819 kmem_cache_free(rbd_obj_request_cache, obj_request);
1823 * Caller is responsible for filling in the list of object requests
1824 * that comprises the image request, and the Linux request pointer
1825 * (if there is one).
1827 static struct rbd_img_request *rbd_img_request_create(
1828 struct rbd_device *rbd_dev,
1829 u64 offset, u64 length,
1833 struct rbd_img_request *img_request;
1835 img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_ATOMIC);
1839 if (write_request) {
1840 down_read(&rbd_dev->header_rwsem);
1841 ceph_get_snap_context(rbd_dev->header.snapc);
1842 up_read(&rbd_dev->header_rwsem);
1845 img_request->rq = NULL;
1846 img_request->rbd_dev = rbd_dev;
1847 img_request->offset = offset;
1848 img_request->length = length;
1849 img_request->flags = 0;
1850 if (write_request) {
1851 img_request_write_set(img_request);
1852 img_request->snapc = rbd_dev->header.snapc;
1854 img_request->snap_id = rbd_dev->spec->snap_id;
1857 img_request_child_set(img_request);
1858 if (rbd_dev->parent_spec)
1859 img_request_layered_set(img_request);
1860 spin_lock_init(&img_request->completion_lock);
1861 img_request->next_completion = 0;
1862 img_request->callback = NULL;
1863 img_request->result = 0;
1864 img_request->obj_request_count = 0;
1865 INIT_LIST_HEAD(&img_request->obj_requests);
1866 kref_init(&img_request->kref);
1868 rbd_img_request_get(img_request); /* Avoid a warning */
1869 rbd_img_request_put(img_request); /* TEMPORARY */
1871 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1872 write_request ? "write" : "read", offset, length,
1878 static void rbd_img_request_destroy(struct kref *kref)
1880 struct rbd_img_request *img_request;
1881 struct rbd_obj_request *obj_request;
1882 struct rbd_obj_request *next_obj_request;
1884 img_request = container_of(kref, struct rbd_img_request, kref);
1886 dout("%s: img %p\n", __func__, img_request);
1888 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1889 rbd_img_obj_request_del(img_request, obj_request);
1890 rbd_assert(img_request->obj_request_count == 0);
1892 if (img_request_write_test(img_request))
1893 ceph_put_snap_context(img_request->snapc);
1895 if (img_request_child_test(img_request))
1896 rbd_obj_request_put(img_request->obj_request);
1898 kmem_cache_free(rbd_img_request_cache, img_request);
1901 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
1903 struct rbd_img_request *img_request;
1904 unsigned int xferred;
1908 rbd_assert(obj_request_img_data_test(obj_request));
1909 img_request = obj_request->img_request;
1911 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
1912 xferred = (unsigned int)obj_request->xferred;
1913 result = obj_request->result;
1915 struct rbd_device *rbd_dev = img_request->rbd_dev;
1917 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
1918 img_request_write_test(img_request) ? "write" : "read",
1919 obj_request->length, obj_request->img_offset,
1920 obj_request->offset);
1921 rbd_warn(rbd_dev, " result %d xferred %x\n",
1923 if (!img_request->result)
1924 img_request->result = result;
1927 /* Image object requests don't own their page array */
1929 if (obj_request->type == OBJ_REQUEST_PAGES) {
1930 obj_request->pages = NULL;
1931 obj_request->page_count = 0;
1934 if (img_request_child_test(img_request)) {
1935 rbd_assert(img_request->obj_request != NULL);
1936 more = obj_request->which < img_request->obj_request_count - 1;
1938 rbd_assert(img_request->rq != NULL);
1939 more = blk_end_request(img_request->rq, result, xferred);
1945 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1947 struct rbd_img_request *img_request;
1948 u32 which = obj_request->which;
1951 rbd_assert(obj_request_img_data_test(obj_request));
1952 img_request = obj_request->img_request;
1954 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1955 rbd_assert(img_request != NULL);
1956 rbd_assert(img_request->obj_request_count > 0);
1957 rbd_assert(which != BAD_WHICH);
1958 rbd_assert(which < img_request->obj_request_count);
1959 rbd_assert(which >= img_request->next_completion);
1961 spin_lock_irq(&img_request->completion_lock);
1962 if (which != img_request->next_completion)
1965 for_each_obj_request_from(img_request, obj_request) {
1967 rbd_assert(which < img_request->obj_request_count);
1969 if (!obj_request_done_test(obj_request))
1971 more = rbd_img_obj_end_request(obj_request);
1975 rbd_assert(more ^ (which == img_request->obj_request_count));
1976 img_request->next_completion = which;
1978 spin_unlock_irq(&img_request->completion_lock);
1981 rbd_img_request_complete(img_request);
1985 * Split up an image request into one or more object requests, each
1986 * to a different object. The "type" parameter indicates whether
1987 * "data_desc" is the pointer to the head of a list of bio
1988 * structures, or the base of a page array. In either case this
1989 * function assumes data_desc describes memory sufficient to hold
1990 * all data described by the image request.
1992 static int rbd_img_request_fill(struct rbd_img_request *img_request,
1993 enum obj_request_type type,
1996 struct rbd_device *rbd_dev = img_request->rbd_dev;
1997 struct rbd_obj_request *obj_request = NULL;
1998 struct rbd_obj_request *next_obj_request;
1999 bool write_request = img_request_write_test(img_request);
2000 struct bio *bio_list;
2001 unsigned int bio_offset = 0;
2002 struct page **pages;
2007 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2008 (int)type, data_desc);
2010 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
2011 img_offset = img_request->offset;
2012 resid = img_request->length;
2013 rbd_assert(resid > 0);
2015 if (type == OBJ_REQUEST_BIO) {
2016 bio_list = data_desc;
2017 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
2019 rbd_assert(type == OBJ_REQUEST_PAGES);
2024 struct ceph_osd_request *osd_req;
2025 const char *object_name;
2029 object_name = rbd_segment_name(rbd_dev, img_offset);
2032 offset = rbd_segment_offset(rbd_dev, img_offset);
2033 length = rbd_segment_length(rbd_dev, img_offset, resid);
2034 obj_request = rbd_obj_request_create(object_name,
2035 offset, length, type);
2036 kfree(object_name); /* object request has its own copy */
2040 if (type == OBJ_REQUEST_BIO) {
2041 unsigned int clone_size;
2043 rbd_assert(length <= (u64)UINT_MAX);
2044 clone_size = (unsigned int)length;
2045 obj_request->bio_list =
2046 bio_chain_clone_range(&bio_list,
2050 if (!obj_request->bio_list)
2053 unsigned int page_count;
2055 obj_request->pages = pages;
2056 page_count = (u32)calc_pages_for(offset, length);
2057 obj_request->page_count = page_count;
2058 if ((offset + length) & ~PAGE_MASK)
2059 page_count--; /* more on last page */
2060 pages += page_count;
2063 osd_req = rbd_osd_req_create(rbd_dev, write_request,
2067 obj_request->osd_req = osd_req;
2068 obj_request->callback = rbd_img_obj_callback;
2070 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
2072 if (type == OBJ_REQUEST_BIO)
2073 osd_req_op_extent_osd_data_bio(osd_req, 0,
2074 obj_request->bio_list, length);
2076 osd_req_op_extent_osd_data_pages(osd_req, 0,
2077 obj_request->pages, length,
2078 offset & ~PAGE_MASK, false, false);
2081 rbd_osd_req_format_write(obj_request);
2083 rbd_osd_req_format_read(obj_request);
2085 obj_request->img_offset = img_offset;
2086 rbd_img_obj_request_add(img_request, obj_request);
2088 img_offset += length;
2095 rbd_obj_request_put(obj_request);
2097 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2098 rbd_obj_request_put(obj_request);
2104 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2106 struct rbd_img_request *img_request;
2107 struct rbd_device *rbd_dev;
2111 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2112 rbd_assert(obj_request_img_data_test(obj_request));
2113 img_request = obj_request->img_request;
2114 rbd_assert(img_request);
2116 rbd_dev = img_request->rbd_dev;
2117 rbd_assert(rbd_dev);
2118 length = (u64)1 << rbd_dev->header.obj_order;
2119 page_count = (u32)calc_pages_for(0, length);
2121 rbd_assert(obj_request->copyup_pages);
2122 ceph_release_page_vector(obj_request->copyup_pages, page_count);
2123 obj_request->copyup_pages = NULL;
2126 * We want the transfer count to reflect the size of the
2127 * original write request. There is no such thing as a
2128 * successful short write, so if the request was successful
2129 * we can just set it to the originally-requested length.
2131 if (!obj_request->result)
2132 obj_request->xferred = obj_request->length;
2134 /* Finish up with the normal image object callback */
2136 rbd_img_obj_callback(obj_request);
2140 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2142 struct rbd_obj_request *orig_request;
2143 struct ceph_osd_request *osd_req;
2144 struct ceph_osd_client *osdc;
2145 struct rbd_device *rbd_dev;
2146 struct page **pages;
2151 rbd_assert(img_request_child_test(img_request));
2153 /* First get what we need from the image request */
2155 pages = img_request->copyup_pages;
2156 rbd_assert(pages != NULL);
2157 img_request->copyup_pages = NULL;
2159 orig_request = img_request->obj_request;
2160 rbd_assert(orig_request != NULL);
2161 rbd_assert(orig_request->type == OBJ_REQUEST_BIO);
2162 result = img_request->result;
2163 obj_size = img_request->length;
2164 xferred = img_request->xferred;
2166 rbd_dev = img_request->rbd_dev;
2167 rbd_assert(rbd_dev);
2168 rbd_assert(obj_size == (u64)1 << rbd_dev->header.obj_order);
2170 rbd_img_request_put(img_request);
2175 /* Allocate the new copyup osd request for the original request */
2178 rbd_assert(!orig_request->osd_req);
2179 osd_req = rbd_osd_req_create_copyup(orig_request);
2182 orig_request->osd_req = osd_req;
2183 orig_request->copyup_pages = pages;
2185 /* Initialize the copyup op */
2187 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2188 osd_req_op_cls_request_data_pages(osd_req, 0, pages, obj_size, 0,
2191 /* Then the original write request op */
2193 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2194 orig_request->offset,
2195 orig_request->length, 0, 0);
2196 osd_req_op_extent_osd_data_bio(osd_req, 1, orig_request->bio_list,
2197 orig_request->length);
2199 rbd_osd_req_format_write(orig_request);
2201 /* All set, send it off. */
2203 orig_request->callback = rbd_img_obj_copyup_callback;
2204 osdc = &rbd_dev->rbd_client->client->osdc;
2205 result = rbd_obj_request_submit(osdc, orig_request);
2209 /* Record the error code and complete the request */
2211 orig_request->result = result;
2212 orig_request->xferred = 0;
2213 obj_request_done_set(orig_request);
2214 rbd_obj_request_complete(orig_request);
2218 * Read from the parent image the range of data that covers the
2219 * entire target of the given object request. This is used for
2220 * satisfying a layered image write request when the target of an
2221 * object request from the image request does not exist.
2223 * A page array big enough to hold the returned data is allocated
2224 * and supplied to rbd_img_request_fill() as the "data descriptor."
2225 * When the read completes, this page array will be transferred to
2226 * the original object request for the copyup operation.
2228 * If an error occurs, record it as the result of the original
2229 * object request and mark it done so it gets completed.
2231 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2233 struct rbd_img_request *img_request = NULL;
2234 struct rbd_img_request *parent_request = NULL;
2235 struct rbd_device *rbd_dev;
2238 struct page **pages = NULL;
2242 rbd_assert(obj_request_img_data_test(obj_request));
2243 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2245 img_request = obj_request->img_request;
2246 rbd_assert(img_request != NULL);
2247 rbd_dev = img_request->rbd_dev;
2248 rbd_assert(rbd_dev->parent != NULL);
2251 * First things first. The original osd request is of no
2252 * use to use any more, we'll need a new one that can hold
2253 * the two ops in a copyup request. We'll get that later,
2254 * but for now we can release the old one.
2256 rbd_osd_req_destroy(obj_request->osd_req);
2257 obj_request->osd_req = NULL;
2260 * Determine the byte range covered by the object in the
2261 * child image to which the original request was to be sent.
2263 img_offset = obj_request->img_offset - obj_request->offset;
2264 length = (u64)1 << rbd_dev->header.obj_order;
2267 * There is no defined parent data beyond the parent
2268 * overlap, so limit what we read at that boundary if
2271 if (img_offset + length > rbd_dev->parent_overlap) {
2272 rbd_assert(img_offset < rbd_dev->parent_overlap);
2273 length = rbd_dev->parent_overlap - img_offset;
2277 * Allocate a page array big enough to receive the data read
2280 page_count = (u32)calc_pages_for(0, length);
2281 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2282 if (IS_ERR(pages)) {
2283 result = PTR_ERR(pages);
2289 parent_request = rbd_img_request_create(rbd_dev->parent,
2292 if (!parent_request)
2294 rbd_obj_request_get(obj_request);
2295 parent_request->obj_request = obj_request;
2297 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2300 parent_request->copyup_pages = pages;
2302 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2303 result = rbd_img_request_submit(parent_request);
2307 parent_request->copyup_pages = NULL;
2308 parent_request->obj_request = NULL;
2309 rbd_obj_request_put(obj_request);
2312 ceph_release_page_vector(pages, page_count);
2314 rbd_img_request_put(parent_request);
2315 obj_request->result = result;
2316 obj_request->xferred = 0;
2317 obj_request_done_set(obj_request);
2322 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2324 struct rbd_obj_request *orig_request;
2327 rbd_assert(!obj_request_img_data_test(obj_request));
2330 * All we need from the object request is the original
2331 * request and the result of the STAT op. Grab those, then
2332 * we're done with the request.
2334 orig_request = obj_request->obj_request;
2335 obj_request->obj_request = NULL;
2336 rbd_assert(orig_request);
2337 rbd_assert(orig_request->img_request);
2339 result = obj_request->result;
2340 obj_request->result = 0;
2342 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2343 obj_request, orig_request, result,
2344 obj_request->xferred, obj_request->length);
2345 rbd_obj_request_put(obj_request);
2347 rbd_assert(orig_request);
2348 rbd_assert(orig_request->img_request);
2351 * Our only purpose here is to determine whether the object
2352 * exists, and we don't want to treat the non-existence as
2353 * an error. If something else comes back, transfer the
2354 * error to the original request and complete it now.
2357 obj_request_existence_set(orig_request, true);
2358 } else if (result == -ENOENT) {
2359 obj_request_existence_set(orig_request, false);
2360 } else if (result) {
2361 orig_request->result = result;
2366 * Resubmit the original request now that we have recorded
2367 * whether the target object exists.
2369 orig_request->result = rbd_img_obj_request_submit(orig_request);
2371 if (orig_request->result)
2372 rbd_obj_request_complete(orig_request);
2373 rbd_obj_request_put(orig_request);
2376 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2378 struct rbd_obj_request *stat_request;
2379 struct rbd_device *rbd_dev;
2380 struct ceph_osd_client *osdc;
2381 struct page **pages = NULL;
2387 * The response data for a STAT call consists of:
2394 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2395 page_count = (u32)calc_pages_for(0, size);
2396 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2398 return PTR_ERR(pages);
2401 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2406 rbd_obj_request_get(obj_request);
2407 stat_request->obj_request = obj_request;
2408 stat_request->pages = pages;
2409 stat_request->page_count = page_count;
2411 rbd_assert(obj_request->img_request);
2412 rbd_dev = obj_request->img_request->rbd_dev;
2413 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2415 if (!stat_request->osd_req)
2417 stat_request->callback = rbd_img_obj_exists_callback;
2419 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2420 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2422 rbd_osd_req_format_read(stat_request);
2424 osdc = &rbd_dev->rbd_client->client->osdc;
2425 ret = rbd_obj_request_submit(osdc, stat_request);
2428 rbd_obj_request_put(obj_request);
2433 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2435 struct rbd_img_request *img_request;
2436 struct rbd_device *rbd_dev;
2439 rbd_assert(obj_request_img_data_test(obj_request));
2441 img_request = obj_request->img_request;
2442 rbd_assert(img_request);
2443 rbd_dev = img_request->rbd_dev;
2446 * Only writes to layered images need special handling.
2447 * Reads and non-layered writes are simple object requests.
2448 * Layered writes that start beyond the end of the overlap
2449 * with the parent have no parent data, so they too are
2450 * simple object requests. Finally, if the target object is
2451 * known to already exist, its parent data has already been
2452 * copied, so a write to the object can also be handled as a
2453 * simple object request.
2455 if (!img_request_write_test(img_request) ||
2456 !img_request_layered_test(img_request) ||
2457 rbd_dev->parent_overlap <= obj_request->img_offset ||
2458 ((known = obj_request_known_test(obj_request)) &&
2459 obj_request_exists_test(obj_request))) {
2461 struct rbd_device *rbd_dev;
2462 struct ceph_osd_client *osdc;
2464 rbd_dev = obj_request->img_request->rbd_dev;
2465 osdc = &rbd_dev->rbd_client->client->osdc;
2467 return rbd_obj_request_submit(osdc, obj_request);
2471 * It's a layered write. The target object might exist but
2472 * we may not know that yet. If we know it doesn't exist,
2473 * start by reading the data for the full target object from
2474 * the parent so we can use it for a copyup to the target.
2477 return rbd_img_obj_parent_read_full(obj_request);
2479 /* We don't know whether the target exists. Go find out. */
2481 return rbd_img_obj_exists_submit(obj_request);
2484 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2486 struct rbd_obj_request *obj_request;
2487 struct rbd_obj_request *next_obj_request;
2489 dout("%s: img %p\n", __func__, img_request);
2490 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2493 ret = rbd_img_obj_request_submit(obj_request);
2501 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2503 struct rbd_obj_request *obj_request;
2504 struct rbd_device *rbd_dev;
2507 rbd_assert(img_request_child_test(img_request));
2509 obj_request = img_request->obj_request;
2510 rbd_assert(obj_request);
2511 rbd_assert(obj_request->img_request);
2513 obj_request->result = img_request->result;
2514 if (obj_request->result)
2518 * We need to zero anything beyond the parent overlap
2519 * boundary. Since rbd_img_obj_request_read_callback()
2520 * will zero anything beyond the end of a short read, an
2521 * easy way to do this is to pretend the data from the
2522 * parent came up short--ending at the overlap boundary.
2524 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2525 obj_end = obj_request->img_offset + obj_request->length;
2526 rbd_dev = obj_request->img_request->rbd_dev;
2527 if (obj_end > rbd_dev->parent_overlap) {
2530 if (obj_request->img_offset < rbd_dev->parent_overlap)
2531 xferred = rbd_dev->parent_overlap -
2532 obj_request->img_offset;
2534 obj_request->xferred = min(img_request->xferred, xferred);
2536 obj_request->xferred = img_request->xferred;
2539 rbd_img_obj_request_read_callback(obj_request);
2540 rbd_obj_request_complete(obj_request);
2543 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2545 struct rbd_device *rbd_dev;
2546 struct rbd_img_request *img_request;
2549 rbd_assert(obj_request_img_data_test(obj_request));
2550 rbd_assert(obj_request->img_request != NULL);
2551 rbd_assert(obj_request->result == (s32) -ENOENT);
2552 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2554 rbd_dev = obj_request->img_request->rbd_dev;
2555 rbd_assert(rbd_dev->parent != NULL);
2556 /* rbd_read_finish(obj_request, obj_request->length); */
2557 img_request = rbd_img_request_create(rbd_dev->parent,
2558 obj_request->img_offset,
2559 obj_request->length,
2565 rbd_obj_request_get(obj_request);
2566 img_request->obj_request = obj_request;
2568 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2569 obj_request->bio_list);
2573 img_request->callback = rbd_img_parent_read_callback;
2574 result = rbd_img_request_submit(img_request);
2581 rbd_img_request_put(img_request);
2582 obj_request->result = result;
2583 obj_request->xferred = 0;
2584 obj_request_done_set(obj_request);
2587 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
2589 struct rbd_obj_request *obj_request;
2590 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2593 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2594 OBJ_REQUEST_NODATA);
2599 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2600 if (!obj_request->osd_req)
2602 obj_request->callback = rbd_obj_request_put;
2604 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2606 rbd_osd_req_format_read(obj_request);
2608 ret = rbd_obj_request_submit(osdc, obj_request);
2611 rbd_obj_request_put(obj_request);
2616 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2618 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2623 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2624 rbd_dev->header_name, (unsigned long long)notify_id,
2625 (unsigned int)opcode);
2626 (void)rbd_dev_refresh(rbd_dev);
2628 rbd_obj_notify_ack(rbd_dev, notify_id);
2632 * Request sync osd watch/unwatch. The value of "start" determines
2633 * whether a watch request is being initiated or torn down.
2635 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start)
2637 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2638 struct rbd_obj_request *obj_request;
2641 rbd_assert(start ^ !!rbd_dev->watch_event);
2642 rbd_assert(start ^ !!rbd_dev->watch_request);
2645 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2646 &rbd_dev->watch_event);
2649 rbd_assert(rbd_dev->watch_event != NULL);
2653 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2654 OBJ_REQUEST_NODATA);
2658 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2659 if (!obj_request->osd_req)
2663 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2665 ceph_osdc_unregister_linger_request(osdc,
2666 rbd_dev->watch_request->osd_req);
2668 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2669 rbd_dev->watch_event->cookie, 0, start);
2670 rbd_osd_req_format_write(obj_request);
2672 ret = rbd_obj_request_submit(osdc, obj_request);
2675 ret = rbd_obj_request_wait(obj_request);
2678 ret = obj_request->result;
2683 * A watch request is set to linger, so the underlying osd
2684 * request won't go away until we unregister it. We retain
2685 * a pointer to the object request during that time (in
2686 * rbd_dev->watch_request), so we'll keep a reference to
2687 * it. We'll drop that reference (below) after we've
2691 rbd_dev->watch_request = obj_request;
2696 /* We have successfully torn down the watch request */
2698 rbd_obj_request_put(rbd_dev->watch_request);
2699 rbd_dev->watch_request = NULL;
2701 /* Cancel the event if we're tearing down, or on error */
2702 ceph_osdc_cancel_event(rbd_dev->watch_event);
2703 rbd_dev->watch_event = NULL;
2705 rbd_obj_request_put(obj_request);
2711 * Synchronous osd object method call. Returns the number of bytes
2712 * returned in the outbound buffer, or a negative error code.
2714 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2715 const char *object_name,
2716 const char *class_name,
2717 const char *method_name,
2718 const void *outbound,
2719 size_t outbound_size,
2721 size_t inbound_size)
2723 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2724 struct rbd_obj_request *obj_request;
2725 struct page **pages;
2730 * Method calls are ultimately read operations. The result
2731 * should placed into the inbound buffer provided. They
2732 * also supply outbound data--parameters for the object
2733 * method. Currently if this is present it will be a
2736 page_count = (u32)calc_pages_for(0, inbound_size);
2737 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2739 return PTR_ERR(pages);
2742 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2747 obj_request->pages = pages;
2748 obj_request->page_count = page_count;
2750 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2751 if (!obj_request->osd_req)
2754 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2755 class_name, method_name);
2756 if (outbound_size) {
2757 struct ceph_pagelist *pagelist;
2759 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2763 ceph_pagelist_init(pagelist);
2764 ceph_pagelist_append(pagelist, outbound, outbound_size);
2765 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2768 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2769 obj_request->pages, inbound_size,
2771 rbd_osd_req_format_read(obj_request);
2773 ret = rbd_obj_request_submit(osdc, obj_request);
2776 ret = rbd_obj_request_wait(obj_request);
2780 ret = obj_request->result;
2784 rbd_assert(obj_request->xferred < (u64)INT_MAX);
2785 ret = (int)obj_request->xferred;
2786 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
2789 rbd_obj_request_put(obj_request);
2791 ceph_release_page_vector(pages, page_count);
2796 static void rbd_request_fn(struct request_queue *q)
2797 __releases(q->queue_lock) __acquires(q->queue_lock)
2799 struct rbd_device *rbd_dev = q->queuedata;
2800 bool read_only = rbd_dev->mapping.read_only;
2804 while ((rq = blk_fetch_request(q))) {
2805 bool write_request = rq_data_dir(rq) == WRITE;
2806 struct rbd_img_request *img_request;
2810 /* Ignore any non-FS requests that filter through. */
2812 if (rq->cmd_type != REQ_TYPE_FS) {
2813 dout("%s: non-fs request type %d\n", __func__,
2814 (int) rq->cmd_type);
2815 __blk_end_request_all(rq, 0);
2819 /* Ignore/skip any zero-length requests */
2821 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
2822 length = (u64) blk_rq_bytes(rq);
2825 dout("%s: zero-length request\n", __func__);
2826 __blk_end_request_all(rq, 0);
2830 spin_unlock_irq(q->queue_lock);
2832 /* Disallow writes to a read-only device */
2834 if (write_request) {
2838 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
2842 * Quit early if the mapped snapshot no longer
2843 * exists. It's still possible the snapshot will
2844 * have disappeared by the time our request arrives
2845 * at the osd, but there's no sense in sending it if
2848 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
2849 dout("request for non-existent snapshot");
2850 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
2856 if (offset && length > U64_MAX - offset + 1) {
2857 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
2859 goto end_request; /* Shouldn't happen */
2863 img_request = rbd_img_request_create(rbd_dev, offset, length,
2864 write_request, false);
2868 img_request->rq = rq;
2870 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2873 result = rbd_img_request_submit(img_request);
2875 rbd_img_request_put(img_request);
2877 spin_lock_irq(q->queue_lock);
2879 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
2880 write_request ? "write" : "read",
2881 length, offset, result);
2883 __blk_end_request_all(rq, result);
2889 * a queue callback. Makes sure that we don't create a bio that spans across
2890 * multiple osd objects. One exception would be with a single page bios,
2891 * which we handle later at bio_chain_clone_range()
2893 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2894 struct bio_vec *bvec)
2896 struct rbd_device *rbd_dev = q->queuedata;
2897 sector_t sector_offset;
2898 sector_t sectors_per_obj;
2899 sector_t obj_sector_offset;
2903 * Find how far into its rbd object the partition-relative
2904 * bio start sector is to offset relative to the enclosing
2907 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2908 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2909 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2912 * Compute the number of bytes from that offset to the end
2913 * of the object. Account for what's already used by the bio.
2915 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2916 if (ret > bmd->bi_size)
2917 ret -= bmd->bi_size;
2922 * Don't send back more than was asked for. And if the bio
2923 * was empty, let the whole thing through because: "Note
2924 * that a block device *must* allow a single page to be
2925 * added to an empty bio."
2927 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2928 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2929 ret = (int) bvec->bv_len;
2934 static void rbd_free_disk(struct rbd_device *rbd_dev)
2936 struct gendisk *disk = rbd_dev->disk;
2941 rbd_dev->disk = NULL;
2942 if (disk->flags & GENHD_FL_UP) {
2945 blk_cleanup_queue(disk->queue);
2950 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2951 const char *object_name,
2952 u64 offset, u64 length, void *buf)
2955 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2956 struct rbd_obj_request *obj_request;
2957 struct page **pages = NULL;
2962 page_count = (u32) calc_pages_for(offset, length);
2963 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2965 ret = PTR_ERR(pages);
2968 obj_request = rbd_obj_request_create(object_name, offset, length,
2973 obj_request->pages = pages;
2974 obj_request->page_count = page_count;
2976 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2977 if (!obj_request->osd_req)
2980 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
2981 offset, length, 0, 0);
2982 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
2984 obj_request->length,
2985 obj_request->offset & ~PAGE_MASK,
2987 rbd_osd_req_format_read(obj_request);
2989 ret = rbd_obj_request_submit(osdc, obj_request);
2992 ret = rbd_obj_request_wait(obj_request);
2996 ret = obj_request->result;
3000 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
3001 size = (size_t) obj_request->xferred;
3002 ceph_copy_from_page_vector(pages, buf, 0, size);
3003 rbd_assert(size <= (size_t)INT_MAX);
3007 rbd_obj_request_put(obj_request);
3009 ceph_release_page_vector(pages, page_count);
3015 * Read the complete header for the given rbd device.
3017 * Returns a pointer to a dynamically-allocated buffer containing
3018 * the complete and validated header. Caller can pass the address
3019 * of a variable that will be filled in with the version of the
3020 * header object at the time it was read.
3022 * Returns a pointer-coded errno if a failure occurs.
3024 static struct rbd_image_header_ondisk *
3025 rbd_dev_v1_header_read(struct rbd_device *rbd_dev)
3027 struct rbd_image_header_ondisk *ondisk = NULL;
3034 * The complete header will include an array of its 64-bit
3035 * snapshot ids, followed by the names of those snapshots as
3036 * a contiguous block of NUL-terminated strings. Note that
3037 * the number of snapshots could change by the time we read
3038 * it in, in which case we re-read it.
3045 size = sizeof (*ondisk);
3046 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
3048 ondisk = kmalloc(size, GFP_KERNEL);
3050 return ERR_PTR(-ENOMEM);
3052 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3056 if ((size_t)ret < size) {
3058 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
3062 if (!rbd_dev_ondisk_valid(ondisk)) {
3064 rbd_warn(rbd_dev, "invalid header");
3068 names_size = le64_to_cpu(ondisk->snap_names_len);
3069 want_count = snap_count;
3070 snap_count = le32_to_cpu(ondisk->snap_count);
3071 } while (snap_count != want_count);
3078 return ERR_PTR(ret);
3082 * reload the ondisk the header
3084 static int rbd_read_header(struct rbd_device *rbd_dev,
3085 struct rbd_image_header *header)
3087 struct rbd_image_header_ondisk *ondisk;
3090 ondisk = rbd_dev_v1_header_read(rbd_dev);
3092 return PTR_ERR(ondisk);
3093 ret = rbd_header_from_disk(header, ondisk);
3099 static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
3101 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
3104 if (rbd_dev->mapping.size != rbd_dev->header.image_size) {
3107 rbd_dev->mapping.size = rbd_dev->header.image_size;
3108 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3109 dout("setting size to %llu sectors", (unsigned long long)size);
3110 set_capacity(rbd_dev->disk, size);
3115 * only read the first part of the ondisk header, without the snaps info
3117 static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev)
3120 struct rbd_image_header h;
3122 ret = rbd_read_header(rbd_dev, &h);
3126 down_write(&rbd_dev->header_rwsem);
3128 /* Update image size, and check for resize of mapped image */
3129 rbd_dev->header.image_size = h.image_size;
3130 rbd_update_mapping_size(rbd_dev);
3132 /* rbd_dev->header.object_prefix shouldn't change */
3133 kfree(rbd_dev->header.snap_sizes);
3134 kfree(rbd_dev->header.snap_names);
3135 /* osd requests may still refer to snapc */
3136 ceph_put_snap_context(rbd_dev->header.snapc);
3138 rbd_dev->header.image_size = h.image_size;
3139 rbd_dev->header.snapc = h.snapc;
3140 rbd_dev->header.snap_names = h.snap_names;
3141 rbd_dev->header.snap_sizes = h.snap_sizes;
3142 /* Free the extra copy of the object prefix */
3143 if (strcmp(rbd_dev->header.object_prefix, h.object_prefix))
3144 rbd_warn(rbd_dev, "object prefix changed (ignoring)");
3145 kfree(h.object_prefix);
3147 up_write(&rbd_dev->header_rwsem);
3153 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
3154 * has disappeared from the (just updated) snapshot context.
3156 static void rbd_exists_validate(struct rbd_device *rbd_dev)
3160 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
3163 snap_id = rbd_dev->spec->snap_id;
3164 if (snap_id == CEPH_NOSNAP)
3167 if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
3168 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3171 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3176 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3177 image_size = rbd_dev->header.image_size;
3178 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3179 if (rbd_dev->image_format == 1)
3180 ret = rbd_dev_v1_refresh(rbd_dev);
3182 ret = rbd_dev_v2_refresh(rbd_dev);
3184 /* If it's a mapped snapshot, validate its EXISTS flag */
3186 rbd_exists_validate(rbd_dev);
3187 mutex_unlock(&ctl_mutex);
3189 rbd_warn(rbd_dev, "got notification but failed to "
3190 " update snaps: %d\n", ret);
3191 if (image_size != rbd_dev->header.image_size)
3192 revalidate_disk(rbd_dev->disk);
3197 static int rbd_init_disk(struct rbd_device *rbd_dev)
3199 struct gendisk *disk;
3200 struct request_queue *q;
3203 /* create gendisk info */
3204 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3208 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3210 disk->major = rbd_dev->major;
3211 disk->first_minor = 0;
3212 disk->fops = &rbd_bd_ops;
3213 disk->private_data = rbd_dev;
3215 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3219 /* We use the default size, but let's be explicit about it. */
3220 blk_queue_physical_block_size(q, SECTOR_SIZE);
3222 /* set io sizes to object size */
3223 segment_size = rbd_obj_bytes(&rbd_dev->header);
3224 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3225 blk_queue_max_segment_size(q, segment_size);
3226 blk_queue_io_min(q, segment_size);
3227 blk_queue_io_opt(q, segment_size);
3229 blk_queue_merge_bvec(q, rbd_merge_bvec);
3232 q->queuedata = rbd_dev;
3234 rbd_dev->disk = disk;
3247 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3249 return container_of(dev, struct rbd_device, dev);
3252 static ssize_t rbd_size_show(struct device *dev,
3253 struct device_attribute *attr, char *buf)
3255 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3257 return sprintf(buf, "%llu\n",
3258 (unsigned long long)rbd_dev->mapping.size);
3262 * Note this shows the features for whatever's mapped, which is not
3263 * necessarily the base image.
3265 static ssize_t rbd_features_show(struct device *dev,
3266 struct device_attribute *attr, char *buf)
3268 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3270 return sprintf(buf, "0x%016llx\n",
3271 (unsigned long long)rbd_dev->mapping.features);
3274 static ssize_t rbd_major_show(struct device *dev,
3275 struct device_attribute *attr, char *buf)
3277 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3280 return sprintf(buf, "%d\n", rbd_dev->major);
3282 return sprintf(buf, "(none)\n");
3286 static ssize_t rbd_client_id_show(struct device *dev,
3287 struct device_attribute *attr, char *buf)
3289 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3291 return sprintf(buf, "client%lld\n",
3292 ceph_client_id(rbd_dev->rbd_client->client));
3295 static ssize_t rbd_pool_show(struct device *dev,
3296 struct device_attribute *attr, char *buf)
3298 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3300 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3303 static ssize_t rbd_pool_id_show(struct device *dev,
3304 struct device_attribute *attr, char *buf)
3306 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3308 return sprintf(buf, "%llu\n",
3309 (unsigned long long) rbd_dev->spec->pool_id);
3312 static ssize_t rbd_name_show(struct device *dev,
3313 struct device_attribute *attr, char *buf)
3315 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3317 if (rbd_dev->spec->image_name)
3318 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3320 return sprintf(buf, "(unknown)\n");
3323 static ssize_t rbd_image_id_show(struct device *dev,
3324 struct device_attribute *attr, char *buf)
3326 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3328 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3332 * Shows the name of the currently-mapped snapshot (or
3333 * RBD_SNAP_HEAD_NAME for the base image).
3335 static ssize_t rbd_snap_show(struct device *dev,
3336 struct device_attribute *attr,
3339 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3341 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3345 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3346 * for the parent image. If there is no parent, simply shows
3347 * "(no parent image)".
3349 static ssize_t rbd_parent_show(struct device *dev,
3350 struct device_attribute *attr,
3353 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3354 struct rbd_spec *spec = rbd_dev->parent_spec;
3359 return sprintf(buf, "(no parent image)\n");
3361 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3362 (unsigned long long) spec->pool_id, spec->pool_name);
3367 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3368 spec->image_name ? spec->image_name : "(unknown)");
3373 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3374 (unsigned long long) spec->snap_id, spec->snap_name);
3379 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3384 return (ssize_t) (bufp - buf);
3387 static ssize_t rbd_image_refresh(struct device *dev,
3388 struct device_attribute *attr,
3392 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3395 ret = rbd_dev_refresh(rbd_dev);
3397 return ret < 0 ? ret : size;
3400 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3401 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3402 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3403 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3404 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3405 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3406 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3407 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3408 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3409 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3410 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3412 static struct attribute *rbd_attrs[] = {
3413 &dev_attr_size.attr,
3414 &dev_attr_features.attr,
3415 &dev_attr_major.attr,
3416 &dev_attr_client_id.attr,
3417 &dev_attr_pool.attr,
3418 &dev_attr_pool_id.attr,
3419 &dev_attr_name.attr,
3420 &dev_attr_image_id.attr,
3421 &dev_attr_current_snap.attr,
3422 &dev_attr_parent.attr,
3423 &dev_attr_refresh.attr,
3427 static struct attribute_group rbd_attr_group = {
3431 static const struct attribute_group *rbd_attr_groups[] = {
3436 static void rbd_sysfs_dev_release(struct device *dev)
3440 static struct device_type rbd_device_type = {
3442 .groups = rbd_attr_groups,
3443 .release = rbd_sysfs_dev_release,
3446 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3448 kref_get(&spec->kref);
3453 static void rbd_spec_free(struct kref *kref);
3454 static void rbd_spec_put(struct rbd_spec *spec)
3457 kref_put(&spec->kref, rbd_spec_free);
3460 static struct rbd_spec *rbd_spec_alloc(void)
3462 struct rbd_spec *spec;
3464 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3467 kref_init(&spec->kref);
3472 static void rbd_spec_free(struct kref *kref)
3474 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3476 kfree(spec->pool_name);
3477 kfree(spec->image_id);
3478 kfree(spec->image_name);
3479 kfree(spec->snap_name);
3483 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3484 struct rbd_spec *spec)
3486 struct rbd_device *rbd_dev;
3488 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3492 spin_lock_init(&rbd_dev->lock);
3494 INIT_LIST_HEAD(&rbd_dev->node);
3495 init_rwsem(&rbd_dev->header_rwsem);
3497 rbd_dev->spec = spec;
3498 rbd_dev->rbd_client = rbdc;
3500 /* Initialize the layout used for all rbd requests */
3502 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3503 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3504 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3505 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3510 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3512 rbd_put_client(rbd_dev->rbd_client);
3513 rbd_spec_put(rbd_dev->spec);
3518 * Get the size and object order for an image snapshot, or if
3519 * snap_id is CEPH_NOSNAP, gets this information for the base
3522 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3523 u8 *order, u64 *snap_size)
3525 __le64 snapid = cpu_to_le64(snap_id);
3530 } __attribute__ ((packed)) size_buf = { 0 };
3532 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3534 &snapid, sizeof (snapid),
3535 &size_buf, sizeof (size_buf));
3536 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3539 if (ret < sizeof (size_buf))
3543 *order = size_buf.order;
3544 *snap_size = le64_to_cpu(size_buf.size);
3546 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3547 (unsigned long long)snap_id, (unsigned int)*order,
3548 (unsigned long long)*snap_size);
3553 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3555 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3556 &rbd_dev->header.obj_order,
3557 &rbd_dev->header.image_size);
3560 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3566 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3570 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3571 "rbd", "get_object_prefix", NULL, 0,
3572 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
3573 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3578 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3579 p + ret, NULL, GFP_NOIO);
3582 if (IS_ERR(rbd_dev->header.object_prefix)) {
3583 ret = PTR_ERR(rbd_dev->header.object_prefix);
3584 rbd_dev->header.object_prefix = NULL;
3586 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3594 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3597 __le64 snapid = cpu_to_le64(snap_id);
3601 } __attribute__ ((packed)) features_buf = { 0 };
3605 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3606 "rbd", "get_features",
3607 &snapid, sizeof (snapid),
3608 &features_buf, sizeof (features_buf));
3609 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3612 if (ret < sizeof (features_buf))
3615 incompat = le64_to_cpu(features_buf.incompat);
3616 if (incompat & ~RBD_FEATURES_SUPPORTED)
3619 *snap_features = le64_to_cpu(features_buf.features);
3621 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3622 (unsigned long long)snap_id,
3623 (unsigned long long)*snap_features,
3624 (unsigned long long)le64_to_cpu(features_buf.incompat));
3629 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3631 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3632 &rbd_dev->header.features);
3635 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3637 struct rbd_spec *parent_spec;
3639 void *reply_buf = NULL;
3647 parent_spec = rbd_spec_alloc();
3651 size = sizeof (__le64) + /* pool_id */
3652 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3653 sizeof (__le64) + /* snap_id */
3654 sizeof (__le64); /* overlap */
3655 reply_buf = kmalloc(size, GFP_KERNEL);
3661 snapid = cpu_to_le64(CEPH_NOSNAP);
3662 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3663 "rbd", "get_parent",
3664 &snapid, sizeof (snapid),
3666 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3671 end = reply_buf + ret;
3673 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
3674 if (parent_spec->pool_id == CEPH_NOPOOL)
3675 goto out; /* No parent? No problem. */
3677 /* The ceph file layout needs to fit pool id in 32 bits */
3680 if (parent_spec->pool_id > (u64)U32_MAX) {
3681 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3682 (unsigned long long)parent_spec->pool_id, U32_MAX);
3686 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3687 if (IS_ERR(image_id)) {
3688 ret = PTR_ERR(image_id);
3691 parent_spec->image_id = image_id;
3692 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3693 ceph_decode_64_safe(&p, end, overlap, out_err);
3695 rbd_dev->parent_overlap = overlap;
3696 rbd_dev->parent_spec = parent_spec;
3697 parent_spec = NULL; /* rbd_dev now owns this */
3702 rbd_spec_put(parent_spec);
3707 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3711 __le64 stripe_count;
3712 } __attribute__ ((packed)) striping_info_buf = { 0 };
3713 size_t size = sizeof (striping_info_buf);
3720 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3721 "rbd", "get_stripe_unit_count", NULL, 0,
3722 (char *)&striping_info_buf, size);
3723 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3730 * We don't actually support the "fancy striping" feature
3731 * (STRIPINGV2) yet, but if the striping sizes are the
3732 * defaults the behavior is the same as before. So find
3733 * out, and only fail if the image has non-default values.
3736 obj_size = (u64)1 << rbd_dev->header.obj_order;
3737 p = &striping_info_buf;
3738 stripe_unit = ceph_decode_64(&p);
3739 if (stripe_unit != obj_size) {
3740 rbd_warn(rbd_dev, "unsupported stripe unit "
3741 "(got %llu want %llu)",
3742 stripe_unit, obj_size);
3745 stripe_count = ceph_decode_64(&p);
3746 if (stripe_count != 1) {
3747 rbd_warn(rbd_dev, "unsupported stripe count "
3748 "(got %llu want 1)", stripe_count);
3751 rbd_dev->header.stripe_unit = stripe_unit;
3752 rbd_dev->header.stripe_count = stripe_count;
3757 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3759 size_t image_id_size;
3764 void *reply_buf = NULL;
3766 char *image_name = NULL;
3769 rbd_assert(!rbd_dev->spec->image_name);
3771 len = strlen(rbd_dev->spec->image_id);
3772 image_id_size = sizeof (__le32) + len;
3773 image_id = kmalloc(image_id_size, GFP_KERNEL);
3778 end = image_id + image_id_size;
3779 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3781 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3782 reply_buf = kmalloc(size, GFP_KERNEL);
3786 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3787 "rbd", "dir_get_name",
3788 image_id, image_id_size,
3793 end = reply_buf + ret;
3795 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3796 if (IS_ERR(image_name))
3799 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3807 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3809 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3810 const char *snap_name;
3813 /* Skip over names until we find the one we are looking for */
3815 snap_name = rbd_dev->header.snap_names;
3816 while (which < snapc->num_snaps) {
3817 if (!strcmp(name, snap_name))
3818 return snapc->snaps[which];
3819 snap_name += strlen(snap_name) + 1;
3825 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3827 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
3832 for (which = 0; !found && which < snapc->num_snaps; which++) {
3833 const char *snap_name;
3835 snap_id = snapc->snaps[which];
3836 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
3837 if (IS_ERR(snap_name))
3839 found = !strcmp(name, snap_name);
3842 return found ? snap_id : CEPH_NOSNAP;
3846 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
3847 * no snapshot by that name is found, or if an error occurs.
3849 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
3851 if (rbd_dev->image_format == 1)
3852 return rbd_v1_snap_id_by_name(rbd_dev, name);
3854 return rbd_v2_snap_id_by_name(rbd_dev, name);
3858 * When an rbd image has a parent image, it is identified by the
3859 * pool, image, and snapshot ids (not names). This function fills
3860 * in the names for those ids. (It's OK if we can't figure out the
3861 * name for an image id, but the pool and snapshot ids should always
3862 * exist and have names.) All names in an rbd spec are dynamically
3865 * When an image being mapped (not a parent) is probed, we have the
3866 * pool name and pool id, image name and image id, and the snapshot
3867 * name. The only thing we're missing is the snapshot id.
3869 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
3871 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3872 struct rbd_spec *spec = rbd_dev->spec;
3873 const char *pool_name;
3874 const char *image_name;
3875 const char *snap_name;
3879 * An image being mapped will have the pool name (etc.), but
3880 * we need to look up the snapshot id.
3882 if (spec->pool_name) {
3883 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
3886 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
3887 if (snap_id == CEPH_NOSNAP)
3889 spec->snap_id = snap_id;
3891 spec->snap_id = CEPH_NOSNAP;
3897 /* Get the pool name; we have to make our own copy of this */
3899 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
3901 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
3904 pool_name = kstrdup(pool_name, GFP_KERNEL);
3908 /* Fetch the image name; tolerate failure here */
3910 image_name = rbd_dev_image_name(rbd_dev);
3912 rbd_warn(rbd_dev, "unable to get image name");
3914 /* Look up the snapshot name, and make a copy */
3916 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
3922 spec->pool_name = pool_name;
3923 spec->image_name = image_name;
3924 spec->snap_name = snap_name;
3934 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
3943 struct ceph_snap_context *snapc;
3947 * We'll need room for the seq value (maximum snapshot id),
3948 * snapshot count, and array of that many snapshot ids.
3949 * For now we have a fixed upper limit on the number we're
3950 * prepared to receive.
3952 size = sizeof (__le64) + sizeof (__le32) +
3953 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3954 reply_buf = kzalloc(size, GFP_KERNEL);
3958 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3959 "rbd", "get_snapcontext", NULL, 0,
3961 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3966 end = reply_buf + ret;
3968 ceph_decode_64_safe(&p, end, seq, out);
3969 ceph_decode_32_safe(&p, end, snap_count, out);
3972 * Make sure the reported number of snapshot ids wouldn't go
3973 * beyond the end of our buffer. But before checking that,
3974 * make sure the computed size of the snapshot context we
3975 * allocate is representable in a size_t.
3977 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
3982 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
3986 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
3992 for (i = 0; i < snap_count; i++)
3993 snapc->snaps[i] = ceph_decode_64(&p);
3995 rbd_dev->header.snapc = snapc;
3997 dout(" snap context seq = %llu, snap_count = %u\n",
3998 (unsigned long long)seq, (unsigned int)snap_count);
4005 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
4016 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
4017 reply_buf = kmalloc(size, GFP_KERNEL);
4019 return ERR_PTR(-ENOMEM);
4021 snapid = cpu_to_le64(snap_id);
4022 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4023 "rbd", "get_snapshot_name",
4024 &snapid, sizeof (snapid),
4026 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4028 snap_name = ERR_PTR(ret);
4033 end = reply_buf + ret;
4034 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4035 if (IS_ERR(snap_name))
4038 dout(" snap_id 0x%016llx snap_name = %s\n",
4039 (unsigned long long)snap_id, snap_name);
4046 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev)
4050 down_write(&rbd_dev->header_rwsem);
4052 ret = rbd_dev_v2_image_size(rbd_dev);
4055 rbd_update_mapping_size(rbd_dev);
4057 ret = rbd_dev_v2_snap_context(rbd_dev);
4058 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4062 up_write(&rbd_dev->header_rwsem);
4067 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4072 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4074 dev = &rbd_dev->dev;
4075 dev->bus = &rbd_bus_type;
4076 dev->type = &rbd_device_type;
4077 dev->parent = &rbd_root_dev;
4078 dev->release = rbd_dev_device_release;
4079 dev_set_name(dev, "%d", rbd_dev->dev_id);
4080 ret = device_register(dev);
4082 mutex_unlock(&ctl_mutex);
4087 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4089 device_unregister(&rbd_dev->dev);
4092 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4095 * Get a unique rbd identifier for the given new rbd_dev, and add
4096 * the rbd_dev to the global list. The minimum rbd id is 1.
4098 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4100 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4102 spin_lock(&rbd_dev_list_lock);
4103 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4104 spin_unlock(&rbd_dev_list_lock);
4105 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4106 (unsigned long long) rbd_dev->dev_id);
4110 * Remove an rbd_dev from the global list, and record that its
4111 * identifier is no longer in use.
4113 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4115 struct list_head *tmp;
4116 int rbd_id = rbd_dev->dev_id;
4119 rbd_assert(rbd_id > 0);
4121 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4122 (unsigned long long) rbd_dev->dev_id);
4123 spin_lock(&rbd_dev_list_lock);
4124 list_del_init(&rbd_dev->node);
4127 * If the id being "put" is not the current maximum, there
4128 * is nothing special we need to do.
4130 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4131 spin_unlock(&rbd_dev_list_lock);
4136 * We need to update the current maximum id. Search the
4137 * list to find out what it is. We're more likely to find
4138 * the maximum at the end, so search the list backward.
4141 list_for_each_prev(tmp, &rbd_dev_list) {
4142 struct rbd_device *rbd_dev;
4144 rbd_dev = list_entry(tmp, struct rbd_device, node);
4145 if (rbd_dev->dev_id > max_id)
4146 max_id = rbd_dev->dev_id;
4148 spin_unlock(&rbd_dev_list_lock);
4151 * The max id could have been updated by rbd_dev_id_get(), in
4152 * which case it now accurately reflects the new maximum.
4153 * Be careful not to overwrite the maximum value in that
4156 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4157 dout(" max dev id has been reset\n");
4161 * Skips over white space at *buf, and updates *buf to point to the
4162 * first found non-space character (if any). Returns the length of
4163 * the token (string of non-white space characters) found. Note
4164 * that *buf must be terminated with '\0'.
4166 static inline size_t next_token(const char **buf)
4169 * These are the characters that produce nonzero for
4170 * isspace() in the "C" and "POSIX" locales.
4172 const char *spaces = " \f\n\r\t\v";
4174 *buf += strspn(*buf, spaces); /* Find start of token */
4176 return strcspn(*buf, spaces); /* Return token length */
4180 * Finds the next token in *buf, and if the provided token buffer is
4181 * big enough, copies the found token into it. The result, if
4182 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4183 * must be terminated with '\0' on entry.
4185 * Returns the length of the token found (not including the '\0').
4186 * Return value will be 0 if no token is found, and it will be >=
4187 * token_size if the token would not fit.
4189 * The *buf pointer will be updated to point beyond the end of the
4190 * found token. Note that this occurs even if the token buffer is
4191 * too small to hold it.
4193 static inline size_t copy_token(const char **buf,
4199 len = next_token(buf);
4200 if (len < token_size) {
4201 memcpy(token, *buf, len);
4202 *(token + len) = '\0';
4210 * Finds the next token in *buf, dynamically allocates a buffer big
4211 * enough to hold a copy of it, and copies the token into the new
4212 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4213 * that a duplicate buffer is created even for a zero-length token.
4215 * Returns a pointer to the newly-allocated duplicate, or a null
4216 * pointer if memory for the duplicate was not available. If
4217 * the lenp argument is a non-null pointer, the length of the token
4218 * (not including the '\0') is returned in *lenp.
4220 * If successful, the *buf pointer will be updated to point beyond
4221 * the end of the found token.
4223 * Note: uses GFP_KERNEL for allocation.
4225 static inline char *dup_token(const char **buf, size_t *lenp)
4230 len = next_token(buf);
4231 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4234 *(dup + len) = '\0';
4244 * Parse the options provided for an "rbd add" (i.e., rbd image
4245 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4246 * and the data written is passed here via a NUL-terminated buffer.
4247 * Returns 0 if successful or an error code otherwise.
4249 * The information extracted from these options is recorded in
4250 * the other parameters which return dynamically-allocated
4253 * The address of a pointer that will refer to a ceph options
4254 * structure. Caller must release the returned pointer using
4255 * ceph_destroy_options() when it is no longer needed.
4257 * Address of an rbd options pointer. Fully initialized by
4258 * this function; caller must release with kfree().
4260 * Address of an rbd image specification pointer. Fully
4261 * initialized by this function based on parsed options.
4262 * Caller must release with rbd_spec_put().
4264 * The options passed take this form:
4265 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4268 * A comma-separated list of one or more monitor addresses.
4269 * A monitor address is an ip address, optionally followed
4270 * by a port number (separated by a colon).
4271 * I.e.: ip1[:port1][,ip2[:port2]...]
4273 * A comma-separated list of ceph and/or rbd options.
4275 * The name of the rados pool containing the rbd image.
4277 * The name of the image in that pool to map.
4279 * An optional snapshot id. If provided, the mapping will
4280 * present data from the image at the time that snapshot was
4281 * created. The image head is used if no snapshot id is
4282 * provided. Snapshot mappings are always read-only.
4284 static int rbd_add_parse_args(const char *buf,
4285 struct ceph_options **ceph_opts,
4286 struct rbd_options **opts,
4287 struct rbd_spec **rbd_spec)
4291 const char *mon_addrs;
4293 size_t mon_addrs_size;
4294 struct rbd_spec *spec = NULL;
4295 struct rbd_options *rbd_opts = NULL;
4296 struct ceph_options *copts;
4299 /* The first four tokens are required */
4301 len = next_token(&buf);
4303 rbd_warn(NULL, "no monitor address(es) provided");
4307 mon_addrs_size = len + 1;
4311 options = dup_token(&buf, NULL);
4315 rbd_warn(NULL, "no options provided");
4319 spec = rbd_spec_alloc();
4323 spec->pool_name = dup_token(&buf, NULL);
4324 if (!spec->pool_name)
4326 if (!*spec->pool_name) {
4327 rbd_warn(NULL, "no pool name provided");
4331 spec->image_name = dup_token(&buf, NULL);
4332 if (!spec->image_name)
4334 if (!*spec->image_name) {
4335 rbd_warn(NULL, "no image name provided");
4340 * Snapshot name is optional; default is to use "-"
4341 * (indicating the head/no snapshot).
4343 len = next_token(&buf);
4345 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4346 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4347 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4348 ret = -ENAMETOOLONG;
4351 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4354 *(snap_name + len) = '\0';
4355 spec->snap_name = snap_name;
4357 /* Initialize all rbd options to the defaults */
4359 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4363 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4365 copts = ceph_parse_options(options, mon_addrs,
4366 mon_addrs + mon_addrs_size - 1,
4367 parse_rbd_opts_token, rbd_opts);
4368 if (IS_ERR(copts)) {
4369 ret = PTR_ERR(copts);
4390 * An rbd format 2 image has a unique identifier, distinct from the
4391 * name given to it by the user. Internally, that identifier is
4392 * what's used to specify the names of objects related to the image.
4394 * A special "rbd id" object is used to map an rbd image name to its
4395 * id. If that object doesn't exist, then there is no v2 rbd image
4396 * with the supplied name.
4398 * This function will record the given rbd_dev's image_id field if
4399 * it can be determined, and in that case will return 0. If any
4400 * errors occur a negative errno will be returned and the rbd_dev's
4401 * image_id field will be unchanged (and should be NULL).
4403 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4412 * When probing a parent image, the image id is already
4413 * known (and the image name likely is not). There's no
4414 * need to fetch the image id again in this case. We
4415 * do still need to set the image format though.
4417 if (rbd_dev->spec->image_id) {
4418 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4424 * First, see if the format 2 image id file exists, and if
4425 * so, get the image's persistent id from it.
4427 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4428 object_name = kmalloc(size, GFP_NOIO);
4431 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4432 dout("rbd id object name is %s\n", object_name);
4434 /* Response will be an encoded string, which includes a length */
4436 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4437 response = kzalloc(size, GFP_NOIO);
4443 /* If it doesn't exist we'll assume it's a format 1 image */
4445 ret = rbd_obj_method_sync(rbd_dev, object_name,
4446 "rbd", "get_id", NULL, 0,
4447 response, RBD_IMAGE_ID_LEN_MAX);
4448 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4449 if (ret == -ENOENT) {
4450 image_id = kstrdup("", GFP_KERNEL);
4451 ret = image_id ? 0 : -ENOMEM;
4453 rbd_dev->image_format = 1;
4454 } else if (ret > sizeof (__le32)) {
4457 image_id = ceph_extract_encoded_string(&p, p + ret,
4459 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4461 rbd_dev->image_format = 2;
4467 rbd_dev->spec->image_id = image_id;
4468 dout("image_id is %s\n", image_id);
4477 /* Undo whatever state changes are made by v1 or v2 image probe */
4479 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
4481 struct rbd_image_header *header;
4483 rbd_dev_remove_parent(rbd_dev);
4484 rbd_spec_put(rbd_dev->parent_spec);
4485 rbd_dev->parent_spec = NULL;
4486 rbd_dev->parent_overlap = 0;
4488 /* Free dynamic fields from the header, then zero it out */
4490 header = &rbd_dev->header;
4491 ceph_put_snap_context(header->snapc);
4492 kfree(header->snap_sizes);
4493 kfree(header->snap_names);
4494 kfree(header->object_prefix);
4495 memset(header, 0, sizeof (*header));
4498 static int rbd_dev_v1_probe(struct rbd_device *rbd_dev)
4502 /* Populate rbd image metadata */
4504 ret = rbd_read_header(rbd_dev, &rbd_dev->header);
4508 /* Version 1 images have no parent (no layering) */
4510 rbd_dev->parent_spec = NULL;
4511 rbd_dev->parent_overlap = 0;
4513 dout("discovered version 1 image, header name is %s\n",
4514 rbd_dev->header_name);
4519 kfree(rbd_dev->header_name);
4520 rbd_dev->header_name = NULL;
4521 kfree(rbd_dev->spec->image_id);
4522 rbd_dev->spec->image_id = NULL;
4527 static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
4531 ret = rbd_dev_v2_image_size(rbd_dev);
4535 /* Get the object prefix (a.k.a. block_name) for the image */
4537 ret = rbd_dev_v2_object_prefix(rbd_dev);
4541 /* Get the and check features for the image */
4543 ret = rbd_dev_v2_features(rbd_dev);
4547 /* If the image supports layering, get the parent info */
4549 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
4550 ret = rbd_dev_v2_parent_info(rbd_dev);
4555 * Don't print a warning for parent images. We can
4556 * tell this point because we won't know its pool
4557 * name yet (just its pool id).
4559 if (rbd_dev->spec->pool_name)
4560 rbd_warn(rbd_dev, "WARNING: kernel layering "
4561 "is EXPERIMENTAL!");
4564 /* If the image supports fancy striping, get its parameters */
4566 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4567 ret = rbd_dev_v2_striping_info(rbd_dev);
4572 /* crypto and compression type aren't (yet) supported for v2 images */
4574 rbd_dev->header.crypt_type = 0;
4575 rbd_dev->header.comp_type = 0;
4577 /* Get the snapshot context, plus the header version */
4579 ret = rbd_dev_v2_snap_context(rbd_dev);
4583 dout("discovered version 2 image, header name is %s\n",
4584 rbd_dev->header_name);
4588 rbd_dev->parent_overlap = 0;
4589 rbd_spec_put(rbd_dev->parent_spec);
4590 rbd_dev->parent_spec = NULL;
4591 kfree(rbd_dev->header_name);
4592 rbd_dev->header_name = NULL;
4593 kfree(rbd_dev->header.object_prefix);
4594 rbd_dev->header.object_prefix = NULL;
4599 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4601 struct rbd_device *parent = NULL;
4602 struct rbd_spec *parent_spec;
4603 struct rbd_client *rbdc;
4606 if (!rbd_dev->parent_spec)
4609 * We need to pass a reference to the client and the parent
4610 * spec when creating the parent rbd_dev. Images related by
4611 * parent/child relationships always share both.
4613 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4614 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4617 parent = rbd_dev_create(rbdc, parent_spec);
4621 ret = rbd_dev_image_probe(parent);
4624 rbd_dev->parent = parent;
4629 rbd_spec_put(rbd_dev->parent_spec);
4630 kfree(rbd_dev->header_name);
4631 rbd_dev_destroy(parent);
4633 rbd_put_client(rbdc);
4634 rbd_spec_put(parent_spec);
4640 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
4644 ret = rbd_dev_mapping_set(rbd_dev);
4648 /* generate unique id: find highest unique id, add one */
4649 rbd_dev_id_get(rbd_dev);
4651 /* Fill in the device name, now that we have its id. */
4652 BUILD_BUG_ON(DEV_NAME_LEN
4653 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4654 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4656 /* Get our block major device number. */
4658 ret = register_blkdev(0, rbd_dev->name);
4661 rbd_dev->major = ret;
4663 /* Set up the blkdev mapping. */
4665 ret = rbd_init_disk(rbd_dev);
4667 goto err_out_blkdev;
4669 ret = rbd_bus_add_dev(rbd_dev);
4673 /* Everything's ready. Announce the disk to the world. */
4675 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4676 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4677 add_disk(rbd_dev->disk);
4679 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4680 (unsigned long long) rbd_dev->mapping.size);
4685 rbd_free_disk(rbd_dev);
4687 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4689 rbd_dev_id_put(rbd_dev);
4690 rbd_dev_mapping_clear(rbd_dev);
4695 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
4697 struct rbd_spec *spec = rbd_dev->spec;
4700 /* Record the header object name for this rbd image. */
4702 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4704 if (rbd_dev->image_format == 1)
4705 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
4707 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
4709 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4710 if (!rbd_dev->header_name)
4713 if (rbd_dev->image_format == 1)
4714 sprintf(rbd_dev->header_name, "%s%s",
4715 spec->image_name, RBD_SUFFIX);
4717 sprintf(rbd_dev->header_name, "%s%s",
4718 RBD_HEADER_PREFIX, spec->image_id);
4722 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
4726 rbd_dev_unprobe(rbd_dev);
4727 ret = rbd_dev_header_watch_sync(rbd_dev, 0);
4729 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
4730 kfree(rbd_dev->header_name);
4731 rbd_dev->header_name = NULL;
4732 rbd_dev->image_format = 0;
4733 kfree(rbd_dev->spec->image_id);
4734 rbd_dev->spec->image_id = NULL;
4736 rbd_dev_destroy(rbd_dev);
4740 * Probe for the existence of the header object for the given rbd
4741 * device. For format 2 images this includes determining the image
4744 static int rbd_dev_image_probe(struct rbd_device *rbd_dev)
4750 * Get the id from the image id object. If it's not a
4751 * format 2 image, we'll get ENOENT back, and we'll assume
4752 * it's a format 1 image.
4754 ret = rbd_dev_image_id(rbd_dev);
4757 rbd_assert(rbd_dev->spec->image_id);
4758 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4760 ret = rbd_dev_header_name(rbd_dev);
4762 goto err_out_format;
4764 ret = rbd_dev_header_watch_sync(rbd_dev, 1);
4766 goto out_header_name;
4768 if (rbd_dev->image_format == 1)
4769 ret = rbd_dev_v1_probe(rbd_dev);
4771 ret = rbd_dev_v2_probe(rbd_dev);
4775 ret = rbd_dev_spec_update(rbd_dev);
4779 ret = rbd_dev_probe_parent(rbd_dev);
4784 rbd_dev_unprobe(rbd_dev);
4786 tmp = rbd_dev_header_watch_sync(rbd_dev, 0);
4788 rbd_warn(rbd_dev, "unable to tear down watch request\n");
4790 kfree(rbd_dev->header_name);
4791 rbd_dev->header_name = NULL;
4793 rbd_dev->image_format = 0;
4794 kfree(rbd_dev->spec->image_id);
4795 rbd_dev->spec->image_id = NULL;
4797 dout("probe failed, returning %d\n", ret);
4802 static ssize_t rbd_add(struct bus_type *bus,
4806 struct rbd_device *rbd_dev = NULL;
4807 struct ceph_options *ceph_opts = NULL;
4808 struct rbd_options *rbd_opts = NULL;
4809 struct rbd_spec *spec = NULL;
4810 struct rbd_client *rbdc;
4811 struct ceph_osd_client *osdc;
4814 if (!try_module_get(THIS_MODULE))
4817 /* parse add command */
4818 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4820 goto err_out_module;
4822 rbdc = rbd_get_client(ceph_opts);
4827 ceph_opts = NULL; /* rbd_dev client now owns this */
4830 osdc = &rbdc->client->osdc;
4831 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4833 goto err_out_client;
4834 spec->pool_id = (u64)rc;
4836 /* The ceph file layout needs to fit pool id in 32 bits */
4838 if (spec->pool_id > (u64)U32_MAX) {
4839 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4840 (unsigned long long)spec->pool_id, U32_MAX);
4842 goto err_out_client;
4845 rbd_dev = rbd_dev_create(rbdc, spec);
4847 goto err_out_client;
4848 rbdc = NULL; /* rbd_dev now owns this */
4849 spec = NULL; /* rbd_dev now owns this */
4851 rbd_dev->mapping.read_only = rbd_opts->read_only;
4853 rbd_opts = NULL; /* done with this */
4855 rc = rbd_dev_image_probe(rbd_dev);
4857 goto err_out_rbd_dev;
4859 rc = rbd_dev_device_setup(rbd_dev);
4863 rbd_dev_image_release(rbd_dev);
4865 rbd_dev_destroy(rbd_dev);
4867 rbd_put_client(rbdc);
4870 ceph_destroy_options(ceph_opts);
4874 module_put(THIS_MODULE);
4876 dout("Error adding device %s\n", buf);
4881 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4883 struct list_head *tmp;
4884 struct rbd_device *rbd_dev;
4886 spin_lock(&rbd_dev_list_lock);
4887 list_for_each(tmp, &rbd_dev_list) {
4888 rbd_dev = list_entry(tmp, struct rbd_device, node);
4889 if (rbd_dev->dev_id == dev_id) {
4890 spin_unlock(&rbd_dev_list_lock);
4894 spin_unlock(&rbd_dev_list_lock);
4898 static void rbd_dev_device_release(struct device *dev)
4900 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4902 rbd_free_disk(rbd_dev);
4903 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4904 rbd_dev_clear_mapping(rbd_dev);
4905 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4907 rbd_dev_id_put(rbd_dev);
4908 rbd_dev_mapping_clear(rbd_dev);
4911 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
4913 while (rbd_dev->parent) {
4914 struct rbd_device *first = rbd_dev;
4915 struct rbd_device *second = first->parent;
4916 struct rbd_device *third;
4919 * Follow to the parent with no grandparent and
4922 while (second && (third = second->parent)) {
4927 rbd_dev_image_release(second);
4928 first->parent = NULL;
4929 first->parent_overlap = 0;
4931 rbd_assert(first->parent_spec);
4932 rbd_spec_put(first->parent_spec);
4933 first->parent_spec = NULL;
4937 static ssize_t rbd_remove(struct bus_type *bus,
4941 struct rbd_device *rbd_dev = NULL;
4946 ret = strict_strtoul(buf, 10, &ul);
4950 /* convert to int; abort if we lost anything in the conversion */
4951 target_id = (int) ul;
4952 if (target_id != ul)
4955 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4957 rbd_dev = __rbd_get_dev(target_id);
4963 spin_lock_irq(&rbd_dev->lock);
4964 if (rbd_dev->open_count)
4967 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
4968 spin_unlock_irq(&rbd_dev->lock);
4972 rbd_bus_del_dev(rbd_dev);
4973 rbd_dev_image_release(rbd_dev);
4974 module_put(THIS_MODULE);
4976 mutex_unlock(&ctl_mutex);
4982 * create control files in sysfs
4985 static int rbd_sysfs_init(void)
4989 ret = device_register(&rbd_root_dev);
4993 ret = bus_register(&rbd_bus_type);
4995 device_unregister(&rbd_root_dev);
5000 static void rbd_sysfs_cleanup(void)
5002 bus_unregister(&rbd_bus_type);
5003 device_unregister(&rbd_root_dev);
5006 static int rbd_slab_init(void)
5008 rbd_assert(!rbd_img_request_cache);
5009 rbd_img_request_cache = kmem_cache_create("rbd_img_request",
5010 sizeof (struct rbd_img_request),
5011 __alignof__(struct rbd_img_request),
5013 if (!rbd_img_request_cache)
5016 rbd_assert(!rbd_obj_request_cache);
5017 rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
5018 sizeof (struct rbd_obj_request),
5019 __alignof__(struct rbd_obj_request),
5021 if (rbd_obj_request_cache)
5024 kmem_cache_destroy(rbd_img_request_cache);
5025 rbd_img_request_cache = NULL;
5030 static void rbd_slab_exit(void)
5032 rbd_assert(rbd_obj_request_cache);
5033 kmem_cache_destroy(rbd_obj_request_cache);
5034 rbd_obj_request_cache = NULL;
5036 rbd_assert(rbd_img_request_cache);
5037 kmem_cache_destroy(rbd_img_request_cache);
5038 rbd_img_request_cache = NULL;
5041 static int __init rbd_init(void)
5045 if (!libceph_compatible(NULL)) {
5046 rbd_warn(NULL, "libceph incompatibility (quitting)");
5050 rc = rbd_slab_init();
5053 rc = rbd_sysfs_init();
5057 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5062 static void __exit rbd_exit(void)
5064 rbd_sysfs_cleanup();
5068 module_init(rbd_init);
5069 module_exit(rbd_exit);
5071 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5072 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5073 MODULE_DESCRIPTION("rados block device");
5075 /* following authorship retained from original osdblk.c */
5076 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5078 MODULE_LICENSE("GPL");