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>
37 #include <linux/kernel.h>
38 #include <linux/device.h>
39 #include <linux/module.h>
41 #include <linux/blkdev.h>
43 #include "rbd_types.h"
45 #define RBD_DEBUG /* Activate rbd_assert() calls */
48 * The basic unit of block I/O is a sector. It is interpreted in a
49 * number of contexts in Linux (blk, bio, genhd), but the default is
50 * universally 512 bytes. These symbols are just slightly more
51 * meaningful than the bare numbers they represent.
53 #define SECTOR_SHIFT 9
54 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT)
56 #define RBD_DRV_NAME "rbd"
57 #define RBD_DRV_NAME_LONG "rbd (rados block device)"
59 #define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
61 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
62 #define RBD_MAX_SNAP_NAME_LEN \
63 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
65 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
67 #define RBD_SNAP_HEAD_NAME "-"
69 #define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
71 /* This allows a single page to hold an image name sent by OSD */
72 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
73 #define RBD_IMAGE_ID_LEN_MAX 64
75 #define RBD_OBJ_PREFIX_LEN_MAX 64
79 #define RBD_FEATURE_LAYERING (1<<0)
80 #define RBD_FEATURE_STRIPINGV2 (1<<1)
81 #define RBD_FEATURES_ALL \
82 (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
84 /* Features supported by this (client software) implementation. */
86 #define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
89 * An RBD device name will be "rbd#", where the "rbd" comes from
90 * RBD_DRV_NAME above, and # is a unique integer identifier.
91 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
92 * enough to hold all possible device names.
94 #define DEV_NAME_LEN 32
95 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
98 * block device image metadata (in-memory version)
100 struct rbd_image_header {
101 /* These four fields never change for a given rbd image */
108 /* The remaining fields need to be updated occasionally */
110 struct ceph_snap_context *snapc;
119 * An rbd image specification.
121 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
122 * identify an image. Each rbd_dev structure includes a pointer to
123 * an rbd_spec structure that encapsulates this identity.
125 * Each of the id's in an rbd_spec has an associated name. For a
126 * user-mapped image, the names are supplied and the id's associated
127 * with them are looked up. For a layered image, a parent image is
128 * defined by the tuple, and the names are looked up.
130 * An rbd_dev structure contains a parent_spec pointer which is
131 * non-null if the image it represents is a child in a layered
132 * image. This pointer will refer to the rbd_spec structure used
133 * by the parent rbd_dev for its own identity (i.e., the structure
134 * is shared between the parent and child).
136 * Since these structures are populated once, during the discovery
137 * phase of image construction, they are effectively immutable so
138 * we make no effort to synchronize access to them.
140 * Note that code herein does not assume the image name is known (it
141 * could be a null pointer).
145 const char *pool_name;
147 const char *image_id;
148 const char *image_name;
151 const char *snap_name;
157 * an instance of the client. multiple devices may share an rbd client.
160 struct ceph_client *client;
162 struct list_head node;
165 struct rbd_img_request;
166 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
168 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
170 struct rbd_obj_request;
171 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
173 enum obj_request_type {
174 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
178 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
179 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
180 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
181 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
184 struct rbd_obj_request {
185 const char *object_name;
186 u64 offset; /* object start byte */
187 u64 length; /* bytes from offset */
191 * An object request associated with an image will have its
192 * img_data flag set; a standalone object request will not.
194 * A standalone object request will have which == BAD_WHICH
195 * and a null obj_request pointer.
197 * An object request initiated in support of a layered image
198 * object (to check for its existence before a write) will
199 * have which == BAD_WHICH and a non-null obj_request pointer.
201 * Finally, an object request for rbd image data will have
202 * which != BAD_WHICH, and will have a non-null img_request
203 * pointer. The value of which will be in the range
204 * 0..(img_request->obj_request_count-1).
207 struct rbd_obj_request *obj_request; /* STAT op */
209 struct rbd_img_request *img_request;
211 /* links for img_request->obj_requests list */
212 struct list_head links;
215 u32 which; /* posn image request list */
217 enum obj_request_type type;
219 struct bio *bio_list;
225 struct page **copyup_pages;
227 struct ceph_osd_request *osd_req;
229 u64 xferred; /* bytes transferred */
232 rbd_obj_callback_t callback;
233 struct completion completion;
239 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
240 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
241 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
244 struct rbd_img_request {
245 struct rbd_device *rbd_dev;
246 u64 offset; /* starting image byte offset */
247 u64 length; /* byte count from offset */
250 u64 snap_id; /* for reads */
251 struct ceph_snap_context *snapc; /* for writes */
254 struct request *rq; /* block request */
255 struct rbd_obj_request *obj_request; /* obj req initiator */
257 struct page **copyup_pages;
258 spinlock_t completion_lock;/* protects next_completion */
260 rbd_img_callback_t callback;
261 u64 xferred;/* aggregate bytes transferred */
262 int result; /* first nonzero obj_request result */
264 u32 obj_request_count;
265 struct list_head obj_requests; /* rbd_obj_request structs */
270 #define for_each_obj_request(ireq, oreq) \
271 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
272 #define for_each_obj_request_from(ireq, oreq) \
273 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
274 #define for_each_obj_request_safe(ireq, oreq, n) \
275 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
280 struct list_head node;
295 int dev_id; /* blkdev unique id */
297 int major; /* blkdev assigned major */
298 struct gendisk *disk; /* blkdev's gendisk and rq */
300 u32 image_format; /* Either 1 or 2 */
301 struct rbd_client *rbd_client;
303 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
305 spinlock_t lock; /* queue, flags, open_count */
307 struct rbd_image_header header;
308 unsigned long flags; /* possibly lock protected */
309 struct rbd_spec *spec;
313 struct ceph_file_layout layout;
315 struct ceph_osd_event *watch_event;
316 struct rbd_obj_request *watch_request;
318 struct rbd_spec *parent_spec;
320 struct rbd_device *parent;
322 /* protects updating the header */
323 struct rw_semaphore header_rwsem;
325 struct rbd_mapping mapping;
327 struct list_head node;
329 /* list of snapshots */
330 struct list_head snaps;
334 unsigned long open_count; /* protected by lock */
338 * Flag bits for rbd_dev->flags. If atomicity is required,
339 * rbd_dev->lock is used to protect access.
341 * Currently, only the "removing" flag (which is coupled with the
342 * "open_count" field) requires atomic access.
345 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
346 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
349 static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
351 static LIST_HEAD(rbd_dev_list); /* devices */
352 static DEFINE_SPINLOCK(rbd_dev_list_lock);
354 static LIST_HEAD(rbd_client_list); /* clients */
355 static DEFINE_SPINLOCK(rbd_client_list_lock);
357 static int rbd_img_request_submit(struct rbd_img_request *img_request);
359 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev);
361 static void rbd_dev_device_release(struct device *dev);
362 static void rbd_snap_destroy(struct rbd_snap *snap);
364 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
366 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
368 static int rbd_dev_image_probe(struct rbd_device *rbd_dev);
370 static struct bus_attribute rbd_bus_attrs[] = {
371 __ATTR(add, S_IWUSR, NULL, rbd_add),
372 __ATTR(remove, S_IWUSR, NULL, rbd_remove),
376 static struct bus_type rbd_bus_type = {
378 .bus_attrs = rbd_bus_attrs,
381 static void rbd_root_dev_release(struct device *dev)
385 static struct device rbd_root_dev = {
387 .release = rbd_root_dev_release,
390 static __printf(2, 3)
391 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
393 struct va_format vaf;
401 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
402 else if (rbd_dev->disk)
403 printk(KERN_WARNING "%s: %s: %pV\n",
404 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
405 else if (rbd_dev->spec && rbd_dev->spec->image_name)
406 printk(KERN_WARNING "%s: image %s: %pV\n",
407 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
408 else if (rbd_dev->spec && rbd_dev->spec->image_id)
409 printk(KERN_WARNING "%s: id %s: %pV\n",
410 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
412 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
413 RBD_DRV_NAME, rbd_dev, &vaf);
418 #define rbd_assert(expr) \
419 if (unlikely(!(expr))) { \
420 printk(KERN_ERR "\nAssertion failure in %s() " \
422 "\trbd_assert(%s);\n\n", \
423 __func__, __LINE__, #expr); \
426 #else /* !RBD_DEBUG */
427 # define rbd_assert(expr) ((void) 0)
428 #endif /* !RBD_DEBUG */
430 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
431 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
432 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
434 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
435 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev);
436 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
439 static int rbd_open(struct block_device *bdev, fmode_t mode)
441 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
442 bool removing = false;
444 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
447 spin_lock_irq(&rbd_dev->lock);
448 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
451 rbd_dev->open_count++;
452 spin_unlock_irq(&rbd_dev->lock);
456 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
457 (void) get_device(&rbd_dev->dev);
458 set_device_ro(bdev, rbd_dev->mapping.read_only);
459 mutex_unlock(&ctl_mutex);
464 static int rbd_release(struct gendisk *disk, fmode_t mode)
466 struct rbd_device *rbd_dev = disk->private_data;
467 unsigned long open_count_before;
469 spin_lock_irq(&rbd_dev->lock);
470 open_count_before = rbd_dev->open_count--;
471 spin_unlock_irq(&rbd_dev->lock);
472 rbd_assert(open_count_before > 0);
474 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
475 put_device(&rbd_dev->dev);
476 mutex_unlock(&ctl_mutex);
481 static const struct block_device_operations rbd_bd_ops = {
482 .owner = THIS_MODULE,
484 .release = rbd_release,
488 * Initialize an rbd client instance.
491 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
493 struct rbd_client *rbdc;
496 dout("%s:\n", __func__);
497 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
501 kref_init(&rbdc->kref);
502 INIT_LIST_HEAD(&rbdc->node);
504 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
506 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
507 if (IS_ERR(rbdc->client))
509 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
511 ret = ceph_open_session(rbdc->client);
515 spin_lock(&rbd_client_list_lock);
516 list_add_tail(&rbdc->node, &rbd_client_list);
517 spin_unlock(&rbd_client_list_lock);
519 mutex_unlock(&ctl_mutex);
520 dout("%s: rbdc %p\n", __func__, rbdc);
525 ceph_destroy_client(rbdc->client);
527 mutex_unlock(&ctl_mutex);
531 ceph_destroy_options(ceph_opts);
532 dout("%s: error %d\n", __func__, ret);
537 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
539 kref_get(&rbdc->kref);
545 * Find a ceph client with specific addr and configuration. If
546 * found, bump its reference count.
548 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
550 struct rbd_client *client_node;
553 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
556 spin_lock(&rbd_client_list_lock);
557 list_for_each_entry(client_node, &rbd_client_list, node) {
558 if (!ceph_compare_options(ceph_opts, client_node->client)) {
559 __rbd_get_client(client_node);
565 spin_unlock(&rbd_client_list_lock);
567 return found ? client_node : NULL;
577 /* string args above */
580 /* Boolean args above */
584 static match_table_t rbd_opts_tokens = {
586 /* string args above */
587 {Opt_read_only, "read_only"},
588 {Opt_read_only, "ro"}, /* Alternate spelling */
589 {Opt_read_write, "read_write"},
590 {Opt_read_write, "rw"}, /* Alternate spelling */
591 /* Boolean args above */
599 #define RBD_READ_ONLY_DEFAULT false
601 static int parse_rbd_opts_token(char *c, void *private)
603 struct rbd_options *rbd_opts = private;
604 substring_t argstr[MAX_OPT_ARGS];
605 int token, intval, ret;
607 token = match_token(c, rbd_opts_tokens, argstr);
611 if (token < Opt_last_int) {
612 ret = match_int(&argstr[0], &intval);
614 pr_err("bad mount option arg (not int) "
618 dout("got int token %d val %d\n", token, intval);
619 } else if (token > Opt_last_int && token < Opt_last_string) {
620 dout("got string token %d val %s\n", token,
622 } else if (token > Opt_last_string && token < Opt_last_bool) {
623 dout("got Boolean token %d\n", token);
625 dout("got token %d\n", token);
630 rbd_opts->read_only = true;
633 rbd_opts->read_only = false;
643 * Get a ceph client with specific addr and configuration, if one does
644 * not exist create it.
646 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
648 struct rbd_client *rbdc;
650 rbdc = rbd_client_find(ceph_opts);
651 if (rbdc) /* using an existing client */
652 ceph_destroy_options(ceph_opts);
654 rbdc = rbd_client_create(ceph_opts);
660 * Destroy ceph client
662 * Caller must hold rbd_client_list_lock.
664 static void rbd_client_release(struct kref *kref)
666 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
668 dout("%s: rbdc %p\n", __func__, rbdc);
669 spin_lock(&rbd_client_list_lock);
670 list_del(&rbdc->node);
671 spin_unlock(&rbd_client_list_lock);
673 ceph_destroy_client(rbdc->client);
678 * Drop reference to ceph client node. If it's not referenced anymore, release
681 static void rbd_put_client(struct rbd_client *rbdc)
684 kref_put(&rbdc->kref, rbd_client_release);
687 static bool rbd_image_format_valid(u32 image_format)
689 return image_format == 1 || image_format == 2;
692 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
697 /* The header has to start with the magic rbd header text */
698 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
701 /* The bio layer requires at least sector-sized I/O */
703 if (ondisk->options.order < SECTOR_SHIFT)
706 /* If we use u64 in a few spots we may be able to loosen this */
708 if (ondisk->options.order > 8 * sizeof (int) - 1)
712 * The size of a snapshot header has to fit in a size_t, and
713 * that limits the number of snapshots.
715 snap_count = le32_to_cpu(ondisk->snap_count);
716 size = SIZE_MAX - sizeof (struct ceph_snap_context);
717 if (snap_count > size / sizeof (__le64))
721 * Not only that, but the size of the entire the snapshot
722 * header must also be representable in a size_t.
724 size -= snap_count * sizeof (__le64);
725 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
732 * Create a new header structure, translate header format from the on-disk
735 static int rbd_header_from_disk(struct rbd_image_header *header,
736 struct rbd_image_header_ondisk *ondisk)
743 memset(header, 0, sizeof (*header));
745 snap_count = le32_to_cpu(ondisk->snap_count);
747 len = strnlen(ondisk->object_prefix, sizeof (ondisk->object_prefix));
748 header->object_prefix = kmalloc(len + 1, GFP_KERNEL);
749 if (!header->object_prefix)
751 memcpy(header->object_prefix, ondisk->object_prefix, len);
752 header->object_prefix[len] = '\0';
755 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
757 /* Save a copy of the snapshot names */
759 if (snap_names_len > (u64) SIZE_MAX)
761 header->snap_names = kmalloc(snap_names_len, GFP_KERNEL);
762 if (!header->snap_names)
765 * Note that rbd_dev_v1_header_read() guarantees
766 * the ondisk buffer we're working with has
767 * snap_names_len bytes beyond the end of the
768 * snapshot id array, this memcpy() is safe.
770 memcpy(header->snap_names, &ondisk->snaps[snap_count],
773 /* Record each snapshot's size */
775 size = snap_count * sizeof (*header->snap_sizes);
776 header->snap_sizes = kmalloc(size, GFP_KERNEL);
777 if (!header->snap_sizes)
779 for (i = 0; i < snap_count; i++)
780 header->snap_sizes[i] =
781 le64_to_cpu(ondisk->snaps[i].image_size);
783 header->snap_names = NULL;
784 header->snap_sizes = NULL;
787 header->features = 0; /* No features support in v1 images */
788 header->obj_order = ondisk->options.order;
789 header->crypt_type = ondisk->options.crypt_type;
790 header->comp_type = ondisk->options.comp_type;
792 /* Allocate and fill in the snapshot context */
794 header->image_size = le64_to_cpu(ondisk->image_size);
796 header->snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
799 header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
800 for (i = 0; i < snap_count; i++)
801 header->snapc->snaps[i] = le64_to_cpu(ondisk->snaps[i].id);
806 kfree(header->snap_sizes);
807 header->snap_sizes = NULL;
808 kfree(header->snap_names);
809 header->snap_names = NULL;
810 kfree(header->object_prefix);
811 header->object_prefix = NULL;
816 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
818 const char *snap_name;
820 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
822 /* Skip over names until we find the one we are looking for */
824 snap_name = rbd_dev->header.snap_names;
826 snap_name += strlen(snap_name) + 1;
828 return kstrdup(snap_name, GFP_KERNEL);
831 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
833 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
836 for (which = 0; which < snapc->num_snaps; which++)
837 if (snapc->snaps[which] == snap_id)
840 return BAD_SNAP_INDEX;
843 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
847 which = rbd_dev_snap_index(rbd_dev, snap_id);
848 if (which == BAD_SNAP_INDEX)
851 return _rbd_dev_v1_snap_name(rbd_dev, which);
854 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
856 if (snap_id == CEPH_NOSNAP)
857 return RBD_SNAP_HEAD_NAME;
859 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
860 if (rbd_dev->image_format == 1)
861 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
863 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
866 static struct rbd_snap *snap_by_name(struct rbd_device *rbd_dev,
867 const char *snap_name)
869 struct rbd_snap *snap;
871 list_for_each_entry(snap, &rbd_dev->snaps, node)
872 if (!strcmp(snap_name, snap->name))
878 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
880 if (!memcmp(rbd_dev->spec->snap_name, RBD_SNAP_HEAD_NAME,
881 sizeof (RBD_SNAP_HEAD_NAME))) {
882 rbd_dev->mapping.size = rbd_dev->header.image_size;
883 rbd_dev->mapping.features = rbd_dev->header.features;
885 struct rbd_snap *snap;
887 snap = snap_by_name(rbd_dev, rbd_dev->spec->snap_name);
890 rbd_dev->mapping.size = snap->size;
891 rbd_dev->mapping.features = snap->features;
892 rbd_dev->mapping.read_only = true;
898 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
900 rbd_dev->mapping.size = 0;
901 rbd_dev->mapping.features = 0;
902 rbd_dev->mapping.read_only = true;
905 static void rbd_dev_clear_mapping(struct rbd_device *rbd_dev)
907 rbd_dev->mapping.size = 0;
908 rbd_dev->mapping.features = 0;
909 rbd_dev->mapping.read_only = true;
912 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
918 name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO);
921 segment = offset >> rbd_dev->header.obj_order;
922 ret = snprintf(name, MAX_OBJ_NAME_SIZE + 1, "%s.%012llx",
923 rbd_dev->header.object_prefix, segment);
924 if (ret < 0 || ret > MAX_OBJ_NAME_SIZE) {
925 pr_err("error formatting segment name for #%llu (%d)\n",
934 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
936 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
938 return offset & (segment_size - 1);
941 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
942 u64 offset, u64 length)
944 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
946 offset &= segment_size - 1;
948 rbd_assert(length <= U64_MAX - offset);
949 if (offset + length > segment_size)
950 length = segment_size - offset;
956 * returns the size of an object in the image
958 static u64 rbd_obj_bytes(struct rbd_image_header *header)
960 return 1 << header->obj_order;
967 static void bio_chain_put(struct bio *chain)
973 chain = chain->bi_next;
979 * zeros a bio chain, starting at specific offset
981 static void zero_bio_chain(struct bio *chain, int start_ofs)
990 bio_for_each_segment(bv, chain, i) {
991 if (pos + bv->bv_len > start_ofs) {
992 int remainder = max(start_ofs - pos, 0);
993 buf = bvec_kmap_irq(bv, &flags);
994 memset(buf + remainder, 0,
995 bv->bv_len - remainder);
996 bvec_kunmap_irq(buf, &flags);
1001 chain = chain->bi_next;
1006 * similar to zero_bio_chain(), zeros data defined by a page array,
1007 * starting at the given byte offset from the start of the array and
1008 * continuing up to the given end offset. The pages array is
1009 * assumed to be big enough to hold all bytes up to the end.
1011 static void zero_pages(struct page **pages, u64 offset, u64 end)
1013 struct page **page = &pages[offset >> PAGE_SHIFT];
1015 rbd_assert(end > offset);
1016 rbd_assert(end - offset <= (u64)SIZE_MAX);
1017 while (offset < end) {
1020 unsigned long flags;
1023 page_offset = (size_t)(offset & ~PAGE_MASK);
1024 length = min(PAGE_SIZE - page_offset, (size_t)(end - offset));
1025 local_irq_save(flags);
1026 kaddr = kmap_atomic(*page);
1027 memset(kaddr + page_offset, 0, length);
1028 kunmap_atomic(kaddr);
1029 local_irq_restore(flags);
1037 * Clone a portion of a bio, starting at the given byte offset
1038 * and continuing for the number of bytes indicated.
1040 static struct bio *bio_clone_range(struct bio *bio_src,
1041 unsigned int offset,
1049 unsigned short end_idx;
1050 unsigned short vcnt;
1053 /* Handle the easy case for the caller */
1055 if (!offset && len == bio_src->bi_size)
1056 return bio_clone(bio_src, gfpmask);
1058 if (WARN_ON_ONCE(!len))
1060 if (WARN_ON_ONCE(len > bio_src->bi_size))
1062 if (WARN_ON_ONCE(offset > bio_src->bi_size - len))
1065 /* Find first affected segment... */
1068 __bio_for_each_segment(bv, bio_src, idx, 0) {
1069 if (resid < bv->bv_len)
1071 resid -= bv->bv_len;
1075 /* ...and the last affected segment */
1078 __bio_for_each_segment(bv, bio_src, end_idx, idx) {
1079 if (resid <= bv->bv_len)
1081 resid -= bv->bv_len;
1083 vcnt = end_idx - idx + 1;
1085 /* Build the clone */
1087 bio = bio_alloc(gfpmask, (unsigned int) vcnt);
1089 return NULL; /* ENOMEM */
1091 bio->bi_bdev = bio_src->bi_bdev;
1092 bio->bi_sector = bio_src->bi_sector + (offset >> SECTOR_SHIFT);
1093 bio->bi_rw = bio_src->bi_rw;
1094 bio->bi_flags |= 1 << BIO_CLONED;
1097 * Copy over our part of the bio_vec, then update the first
1098 * and last (or only) entries.
1100 memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[idx],
1101 vcnt * sizeof (struct bio_vec));
1102 bio->bi_io_vec[0].bv_offset += voff;
1104 bio->bi_io_vec[0].bv_len -= voff;
1105 bio->bi_io_vec[vcnt - 1].bv_len = resid;
1107 bio->bi_io_vec[0].bv_len = len;
1110 bio->bi_vcnt = vcnt;
1118 * Clone a portion of a bio chain, starting at the given byte offset
1119 * into the first bio in the source chain and continuing for the
1120 * number of bytes indicated. The result is another bio chain of
1121 * exactly the given length, or a null pointer on error.
1123 * The bio_src and offset parameters are both in-out. On entry they
1124 * refer to the first source bio and the offset into that bio where
1125 * the start of data to be cloned is located.
1127 * On return, bio_src is updated to refer to the bio in the source
1128 * chain that contains first un-cloned byte, and *offset will
1129 * contain the offset of that byte within that bio.
1131 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1132 unsigned int *offset,
1136 struct bio *bi = *bio_src;
1137 unsigned int off = *offset;
1138 struct bio *chain = NULL;
1141 /* Build up a chain of clone bios up to the limit */
1143 if (!bi || off >= bi->bi_size || !len)
1144 return NULL; /* Nothing to clone */
1148 unsigned int bi_size;
1152 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1153 goto out_err; /* EINVAL; ran out of bio's */
1155 bi_size = min_t(unsigned int, bi->bi_size - off, len);
1156 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1158 goto out_err; /* ENOMEM */
1161 end = &bio->bi_next;
1164 if (off == bi->bi_size) {
1175 bio_chain_put(chain);
1181 * The default/initial value for all object request flags is 0. For
1182 * each flag, once its value is set to 1 it is never reset to 0
1185 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1187 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1188 struct rbd_device *rbd_dev;
1190 rbd_dev = obj_request->img_request->rbd_dev;
1191 rbd_warn(rbd_dev, "obj_request %p already marked img_data\n",
1196 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1199 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1202 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1204 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1205 struct rbd_device *rbd_dev = NULL;
1207 if (obj_request_img_data_test(obj_request))
1208 rbd_dev = obj_request->img_request->rbd_dev;
1209 rbd_warn(rbd_dev, "obj_request %p already marked done\n",
1214 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1217 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1221 * This sets the KNOWN flag after (possibly) setting the EXISTS
1222 * flag. The latter is set based on the "exists" value provided.
1224 * Note that for our purposes once an object exists it never goes
1225 * away again. It's possible that the response from two existence
1226 * checks are separated by the creation of the target object, and
1227 * the first ("doesn't exist") response arrives *after* the second
1228 * ("does exist"). In that case we ignore the second one.
1230 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1234 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1235 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1239 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1242 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1245 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1248 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1251 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1253 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1254 atomic_read(&obj_request->kref.refcount));
1255 kref_get(&obj_request->kref);
1258 static void rbd_obj_request_destroy(struct kref *kref);
1259 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1261 rbd_assert(obj_request != NULL);
1262 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1263 atomic_read(&obj_request->kref.refcount));
1264 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1267 static void rbd_img_request_get(struct rbd_img_request *img_request)
1269 dout("%s: img %p (was %d)\n", __func__, img_request,
1270 atomic_read(&img_request->kref.refcount));
1271 kref_get(&img_request->kref);
1274 static void rbd_img_request_destroy(struct kref *kref);
1275 static void rbd_img_request_put(struct rbd_img_request *img_request)
1277 rbd_assert(img_request != NULL);
1278 dout("%s: img %p (was %d)\n", __func__, img_request,
1279 atomic_read(&img_request->kref.refcount));
1280 kref_put(&img_request->kref, rbd_img_request_destroy);
1283 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1284 struct rbd_obj_request *obj_request)
1286 rbd_assert(obj_request->img_request == NULL);
1288 /* Image request now owns object's original reference */
1289 obj_request->img_request = img_request;
1290 obj_request->which = img_request->obj_request_count;
1291 rbd_assert(!obj_request_img_data_test(obj_request));
1292 obj_request_img_data_set(obj_request);
1293 rbd_assert(obj_request->which != BAD_WHICH);
1294 img_request->obj_request_count++;
1295 list_add_tail(&obj_request->links, &img_request->obj_requests);
1296 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1297 obj_request->which);
1300 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1301 struct rbd_obj_request *obj_request)
1303 rbd_assert(obj_request->which != BAD_WHICH);
1305 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1306 obj_request->which);
1307 list_del(&obj_request->links);
1308 rbd_assert(img_request->obj_request_count > 0);
1309 img_request->obj_request_count--;
1310 rbd_assert(obj_request->which == img_request->obj_request_count);
1311 obj_request->which = BAD_WHICH;
1312 rbd_assert(obj_request_img_data_test(obj_request));
1313 rbd_assert(obj_request->img_request == img_request);
1314 obj_request->img_request = NULL;
1315 obj_request->callback = NULL;
1316 rbd_obj_request_put(obj_request);
1319 static bool obj_request_type_valid(enum obj_request_type type)
1322 case OBJ_REQUEST_NODATA:
1323 case OBJ_REQUEST_BIO:
1324 case OBJ_REQUEST_PAGES:
1331 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1332 struct rbd_obj_request *obj_request)
1334 dout("%s: osdc %p obj %p\n", __func__, osdc, obj_request);
1336 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1339 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1342 dout("%s: img %p\n", __func__, img_request);
1345 * If no error occurred, compute the aggregate transfer
1346 * count for the image request. We could instead use
1347 * atomic64_cmpxchg() to update it as each object request
1348 * completes; not clear which way is better off hand.
1350 if (!img_request->result) {
1351 struct rbd_obj_request *obj_request;
1354 for_each_obj_request(img_request, obj_request)
1355 xferred += obj_request->xferred;
1356 img_request->xferred = xferred;
1359 if (img_request->callback)
1360 img_request->callback(img_request);
1362 rbd_img_request_put(img_request);
1365 /* Caller is responsible for rbd_obj_request_destroy(obj_request) */
1367 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1369 dout("%s: obj %p\n", __func__, obj_request);
1371 return wait_for_completion_interruptible(&obj_request->completion);
1375 * The default/initial value for all image request flags is 0. Each
1376 * is conditionally set to 1 at image request initialization time
1377 * and currently never change thereafter.
1379 static void img_request_write_set(struct rbd_img_request *img_request)
1381 set_bit(IMG_REQ_WRITE, &img_request->flags);
1385 static bool img_request_write_test(struct rbd_img_request *img_request)
1388 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1391 static void img_request_child_set(struct rbd_img_request *img_request)
1393 set_bit(IMG_REQ_CHILD, &img_request->flags);
1397 static bool img_request_child_test(struct rbd_img_request *img_request)
1400 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1403 static void img_request_layered_set(struct rbd_img_request *img_request)
1405 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1409 static bool img_request_layered_test(struct rbd_img_request *img_request)
1412 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1416 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1418 u64 xferred = obj_request->xferred;
1419 u64 length = obj_request->length;
1421 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1422 obj_request, obj_request->img_request, obj_request->result,
1425 * ENOENT means a hole in the image. We zero-fill the
1426 * entire length of the request. A short read also implies
1427 * zero-fill to the end of the request. Either way we
1428 * update the xferred count to indicate the whole request
1431 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1432 if (obj_request->result == -ENOENT) {
1433 if (obj_request->type == OBJ_REQUEST_BIO)
1434 zero_bio_chain(obj_request->bio_list, 0);
1436 zero_pages(obj_request->pages, 0, length);
1437 obj_request->result = 0;
1438 obj_request->xferred = length;
1439 } else if (xferred < length && !obj_request->result) {
1440 if (obj_request->type == OBJ_REQUEST_BIO)
1441 zero_bio_chain(obj_request->bio_list, xferred);
1443 zero_pages(obj_request->pages, xferred, length);
1444 obj_request->xferred = length;
1446 obj_request_done_set(obj_request);
1449 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1451 dout("%s: obj %p cb %p\n", __func__, obj_request,
1452 obj_request->callback);
1453 if (obj_request->callback)
1454 obj_request->callback(obj_request);
1456 complete_all(&obj_request->completion);
1459 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1461 dout("%s: obj %p\n", __func__, obj_request);
1462 obj_request_done_set(obj_request);
1465 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1467 struct rbd_img_request *img_request = NULL;
1468 struct rbd_device *rbd_dev = NULL;
1469 bool layered = false;
1471 if (obj_request_img_data_test(obj_request)) {
1472 img_request = obj_request->img_request;
1473 layered = img_request && img_request_layered_test(img_request);
1474 rbd_dev = img_request->rbd_dev;
1477 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1478 obj_request, img_request, obj_request->result,
1479 obj_request->xferred, obj_request->length);
1480 if (layered && obj_request->result == -ENOENT &&
1481 obj_request->img_offset < rbd_dev->parent_overlap)
1482 rbd_img_parent_read(obj_request);
1483 else if (img_request)
1484 rbd_img_obj_request_read_callback(obj_request);
1486 obj_request_done_set(obj_request);
1489 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1491 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1492 obj_request->result, obj_request->length);
1494 * There is no such thing as a successful short write. Set
1495 * it to our originally-requested length.
1497 obj_request->xferred = obj_request->length;
1498 obj_request_done_set(obj_request);
1502 * For a simple stat call there's nothing to do. We'll do more if
1503 * this is part of a write sequence for a layered image.
1505 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1507 dout("%s: obj %p\n", __func__, obj_request);
1508 obj_request_done_set(obj_request);
1511 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1512 struct ceph_msg *msg)
1514 struct rbd_obj_request *obj_request = osd_req->r_priv;
1517 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1518 rbd_assert(osd_req == obj_request->osd_req);
1519 if (obj_request_img_data_test(obj_request)) {
1520 rbd_assert(obj_request->img_request);
1521 rbd_assert(obj_request->which != BAD_WHICH);
1523 rbd_assert(obj_request->which == BAD_WHICH);
1526 if (osd_req->r_result < 0)
1527 obj_request->result = osd_req->r_result;
1529 BUG_ON(osd_req->r_num_ops > 2);
1532 * We support a 64-bit length, but ultimately it has to be
1533 * passed to blk_end_request(), which takes an unsigned int.
1535 obj_request->xferred = osd_req->r_reply_op_len[0];
1536 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1537 opcode = osd_req->r_ops[0].op;
1539 case CEPH_OSD_OP_READ:
1540 rbd_osd_read_callback(obj_request);
1542 case CEPH_OSD_OP_WRITE:
1543 rbd_osd_write_callback(obj_request);
1545 case CEPH_OSD_OP_STAT:
1546 rbd_osd_stat_callback(obj_request);
1548 case CEPH_OSD_OP_CALL:
1549 case CEPH_OSD_OP_NOTIFY_ACK:
1550 case CEPH_OSD_OP_WATCH:
1551 rbd_osd_trivial_callback(obj_request);
1554 rbd_warn(NULL, "%s: unsupported op %hu\n",
1555 obj_request->object_name, (unsigned short) opcode);
1559 if (obj_request_done_test(obj_request))
1560 rbd_obj_request_complete(obj_request);
1563 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1565 struct rbd_img_request *img_request = obj_request->img_request;
1566 struct ceph_osd_request *osd_req = obj_request->osd_req;
1569 rbd_assert(osd_req != NULL);
1571 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1572 ceph_osdc_build_request(osd_req, obj_request->offset,
1573 NULL, snap_id, NULL);
1576 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1578 struct rbd_img_request *img_request = obj_request->img_request;
1579 struct ceph_osd_request *osd_req = obj_request->osd_req;
1580 struct ceph_snap_context *snapc;
1581 struct timespec mtime = CURRENT_TIME;
1583 rbd_assert(osd_req != NULL);
1585 snapc = img_request ? img_request->snapc : NULL;
1586 ceph_osdc_build_request(osd_req, obj_request->offset,
1587 snapc, CEPH_NOSNAP, &mtime);
1590 static struct ceph_osd_request *rbd_osd_req_create(
1591 struct rbd_device *rbd_dev,
1593 struct rbd_obj_request *obj_request)
1595 struct ceph_snap_context *snapc = NULL;
1596 struct ceph_osd_client *osdc;
1597 struct ceph_osd_request *osd_req;
1599 if (obj_request_img_data_test(obj_request)) {
1600 struct rbd_img_request *img_request = obj_request->img_request;
1602 rbd_assert(write_request ==
1603 img_request_write_test(img_request));
1605 snapc = img_request->snapc;
1608 /* Allocate and initialize the request, for the single op */
1610 osdc = &rbd_dev->rbd_client->client->osdc;
1611 osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
1613 return NULL; /* ENOMEM */
1616 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1618 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1620 osd_req->r_callback = rbd_osd_req_callback;
1621 osd_req->r_priv = obj_request;
1623 osd_req->r_oid_len = strlen(obj_request->object_name);
1624 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1625 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1627 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1633 * Create a copyup osd request based on the information in the
1634 * object request supplied. A copyup request has two osd ops,
1635 * a copyup method call, and a "normal" write request.
1637 static struct ceph_osd_request *
1638 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1640 struct rbd_img_request *img_request;
1641 struct ceph_snap_context *snapc;
1642 struct rbd_device *rbd_dev;
1643 struct ceph_osd_client *osdc;
1644 struct ceph_osd_request *osd_req;
1646 rbd_assert(obj_request_img_data_test(obj_request));
1647 img_request = obj_request->img_request;
1648 rbd_assert(img_request);
1649 rbd_assert(img_request_write_test(img_request));
1651 /* Allocate and initialize the request, for the two ops */
1653 snapc = img_request->snapc;
1654 rbd_dev = img_request->rbd_dev;
1655 osdc = &rbd_dev->rbd_client->client->osdc;
1656 osd_req = ceph_osdc_alloc_request(osdc, snapc, 2, false, GFP_ATOMIC);
1658 return NULL; /* ENOMEM */
1660 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1661 osd_req->r_callback = rbd_osd_req_callback;
1662 osd_req->r_priv = obj_request;
1664 osd_req->r_oid_len = strlen(obj_request->object_name);
1665 rbd_assert(osd_req->r_oid_len < sizeof (osd_req->r_oid));
1666 memcpy(osd_req->r_oid, obj_request->object_name, osd_req->r_oid_len);
1668 osd_req->r_file_layout = rbd_dev->layout; /* struct */
1674 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
1676 ceph_osdc_put_request(osd_req);
1679 /* object_name is assumed to be a non-null pointer and NUL-terminated */
1681 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
1682 u64 offset, u64 length,
1683 enum obj_request_type type)
1685 struct rbd_obj_request *obj_request;
1689 rbd_assert(obj_request_type_valid(type));
1691 size = strlen(object_name) + 1;
1692 obj_request = kzalloc(sizeof (*obj_request) + size, GFP_KERNEL);
1696 name = (char *)(obj_request + 1);
1697 obj_request->object_name = memcpy(name, object_name, size);
1698 obj_request->offset = offset;
1699 obj_request->length = length;
1700 obj_request->flags = 0;
1701 obj_request->which = BAD_WHICH;
1702 obj_request->type = type;
1703 INIT_LIST_HEAD(&obj_request->links);
1704 init_completion(&obj_request->completion);
1705 kref_init(&obj_request->kref);
1707 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
1708 offset, length, (int)type, obj_request);
1713 static void rbd_obj_request_destroy(struct kref *kref)
1715 struct rbd_obj_request *obj_request;
1717 obj_request = container_of(kref, struct rbd_obj_request, kref);
1719 dout("%s: obj %p\n", __func__, obj_request);
1721 rbd_assert(obj_request->img_request == NULL);
1722 rbd_assert(obj_request->which == BAD_WHICH);
1724 if (obj_request->osd_req)
1725 rbd_osd_req_destroy(obj_request->osd_req);
1727 rbd_assert(obj_request_type_valid(obj_request->type));
1728 switch (obj_request->type) {
1729 case OBJ_REQUEST_NODATA:
1730 break; /* Nothing to do */
1731 case OBJ_REQUEST_BIO:
1732 if (obj_request->bio_list)
1733 bio_chain_put(obj_request->bio_list);
1735 case OBJ_REQUEST_PAGES:
1736 if (obj_request->pages)
1737 ceph_release_page_vector(obj_request->pages,
1738 obj_request->page_count);
1746 * Caller is responsible for filling in the list of object requests
1747 * that comprises the image request, and the Linux request pointer
1748 * (if there is one).
1750 static struct rbd_img_request *rbd_img_request_create(
1751 struct rbd_device *rbd_dev,
1752 u64 offset, u64 length,
1756 struct rbd_img_request *img_request;
1758 img_request = kmalloc(sizeof (*img_request), GFP_ATOMIC);
1762 if (write_request) {
1763 down_read(&rbd_dev->header_rwsem);
1764 ceph_get_snap_context(rbd_dev->header.snapc);
1765 up_read(&rbd_dev->header_rwsem);
1768 img_request->rq = NULL;
1769 img_request->rbd_dev = rbd_dev;
1770 img_request->offset = offset;
1771 img_request->length = length;
1772 img_request->flags = 0;
1773 if (write_request) {
1774 img_request_write_set(img_request);
1775 img_request->snapc = rbd_dev->header.snapc;
1777 img_request->snap_id = rbd_dev->spec->snap_id;
1780 img_request_child_set(img_request);
1781 if (rbd_dev->parent_spec)
1782 img_request_layered_set(img_request);
1783 spin_lock_init(&img_request->completion_lock);
1784 img_request->next_completion = 0;
1785 img_request->callback = NULL;
1786 img_request->result = 0;
1787 img_request->obj_request_count = 0;
1788 INIT_LIST_HEAD(&img_request->obj_requests);
1789 kref_init(&img_request->kref);
1791 rbd_img_request_get(img_request); /* Avoid a warning */
1792 rbd_img_request_put(img_request); /* TEMPORARY */
1794 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
1795 write_request ? "write" : "read", offset, length,
1801 static void rbd_img_request_destroy(struct kref *kref)
1803 struct rbd_img_request *img_request;
1804 struct rbd_obj_request *obj_request;
1805 struct rbd_obj_request *next_obj_request;
1807 img_request = container_of(kref, struct rbd_img_request, kref);
1809 dout("%s: img %p\n", __func__, img_request);
1811 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1812 rbd_img_obj_request_del(img_request, obj_request);
1813 rbd_assert(img_request->obj_request_count == 0);
1815 if (img_request_write_test(img_request))
1816 ceph_put_snap_context(img_request->snapc);
1818 if (img_request_child_test(img_request))
1819 rbd_obj_request_put(img_request->obj_request);
1824 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
1826 struct rbd_img_request *img_request;
1827 unsigned int xferred;
1831 rbd_assert(obj_request_img_data_test(obj_request));
1832 img_request = obj_request->img_request;
1834 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
1835 xferred = (unsigned int)obj_request->xferred;
1836 result = obj_request->result;
1838 struct rbd_device *rbd_dev = img_request->rbd_dev;
1840 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",
1841 img_request_write_test(img_request) ? "write" : "read",
1842 obj_request->length, obj_request->img_offset,
1843 obj_request->offset);
1844 rbd_warn(rbd_dev, " result %d xferred %x\n",
1846 if (!img_request->result)
1847 img_request->result = result;
1850 /* Image object requests don't own their page array */
1852 if (obj_request->type == OBJ_REQUEST_PAGES) {
1853 obj_request->pages = NULL;
1854 obj_request->page_count = 0;
1857 if (img_request_child_test(img_request)) {
1858 rbd_assert(img_request->obj_request != NULL);
1859 more = obj_request->which < img_request->obj_request_count - 1;
1861 rbd_assert(img_request->rq != NULL);
1862 more = blk_end_request(img_request->rq, result, xferred);
1868 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
1870 struct rbd_img_request *img_request;
1871 u32 which = obj_request->which;
1874 rbd_assert(obj_request_img_data_test(obj_request));
1875 img_request = obj_request->img_request;
1877 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1878 rbd_assert(img_request != NULL);
1879 rbd_assert(img_request->obj_request_count > 0);
1880 rbd_assert(which != BAD_WHICH);
1881 rbd_assert(which < img_request->obj_request_count);
1882 rbd_assert(which >= img_request->next_completion);
1884 spin_lock_irq(&img_request->completion_lock);
1885 if (which != img_request->next_completion)
1888 for_each_obj_request_from(img_request, obj_request) {
1890 rbd_assert(which < img_request->obj_request_count);
1892 if (!obj_request_done_test(obj_request))
1894 more = rbd_img_obj_end_request(obj_request);
1898 rbd_assert(more ^ (which == img_request->obj_request_count));
1899 img_request->next_completion = which;
1901 spin_unlock_irq(&img_request->completion_lock);
1904 rbd_img_request_complete(img_request);
1908 * Split up an image request into one or more object requests, each
1909 * to a different object. The "type" parameter indicates whether
1910 * "data_desc" is the pointer to the head of a list of bio
1911 * structures, or the base of a page array. In either case this
1912 * function assumes data_desc describes memory sufficient to hold
1913 * all data described by the image request.
1915 static int rbd_img_request_fill(struct rbd_img_request *img_request,
1916 enum obj_request_type type,
1919 struct rbd_device *rbd_dev = img_request->rbd_dev;
1920 struct rbd_obj_request *obj_request = NULL;
1921 struct rbd_obj_request *next_obj_request;
1922 bool write_request = img_request_write_test(img_request);
1923 struct bio *bio_list;
1924 unsigned int bio_offset = 0;
1925 struct page **pages;
1930 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
1931 (int)type, data_desc);
1933 opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
1934 img_offset = img_request->offset;
1935 resid = img_request->length;
1936 rbd_assert(resid > 0);
1938 if (type == OBJ_REQUEST_BIO) {
1939 bio_list = data_desc;
1940 rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
1942 rbd_assert(type == OBJ_REQUEST_PAGES);
1947 struct ceph_osd_request *osd_req;
1948 const char *object_name;
1952 object_name = rbd_segment_name(rbd_dev, img_offset);
1955 offset = rbd_segment_offset(rbd_dev, img_offset);
1956 length = rbd_segment_length(rbd_dev, img_offset, resid);
1957 obj_request = rbd_obj_request_create(object_name,
1958 offset, length, type);
1959 kfree(object_name); /* object request has its own copy */
1963 if (type == OBJ_REQUEST_BIO) {
1964 unsigned int clone_size;
1966 rbd_assert(length <= (u64)UINT_MAX);
1967 clone_size = (unsigned int)length;
1968 obj_request->bio_list =
1969 bio_chain_clone_range(&bio_list,
1973 if (!obj_request->bio_list)
1976 unsigned int page_count;
1978 obj_request->pages = pages;
1979 page_count = (u32)calc_pages_for(offset, length);
1980 obj_request->page_count = page_count;
1981 if ((offset + length) & ~PAGE_MASK)
1982 page_count--; /* more on last page */
1983 pages += page_count;
1986 osd_req = rbd_osd_req_create(rbd_dev, write_request,
1990 obj_request->osd_req = osd_req;
1991 obj_request->callback = rbd_img_obj_callback;
1993 osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
1995 if (type == OBJ_REQUEST_BIO)
1996 osd_req_op_extent_osd_data_bio(osd_req, 0,
1997 obj_request->bio_list, length);
1999 osd_req_op_extent_osd_data_pages(osd_req, 0,
2000 obj_request->pages, length,
2001 offset & ~PAGE_MASK, false, false);
2004 rbd_osd_req_format_write(obj_request);
2006 rbd_osd_req_format_read(obj_request);
2008 obj_request->img_offset = img_offset;
2009 rbd_img_obj_request_add(img_request, obj_request);
2011 img_offset += length;
2018 rbd_obj_request_put(obj_request);
2020 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2021 rbd_obj_request_put(obj_request);
2027 rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request)
2029 struct rbd_img_request *img_request;
2030 struct rbd_device *rbd_dev;
2034 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2035 rbd_assert(obj_request_img_data_test(obj_request));
2036 img_request = obj_request->img_request;
2037 rbd_assert(img_request);
2039 rbd_dev = img_request->rbd_dev;
2040 rbd_assert(rbd_dev);
2041 length = (u64)1 << rbd_dev->header.obj_order;
2042 page_count = (u32)calc_pages_for(0, length);
2044 rbd_assert(obj_request->copyup_pages);
2045 ceph_release_page_vector(obj_request->copyup_pages, page_count);
2046 obj_request->copyup_pages = NULL;
2049 * We want the transfer count to reflect the size of the
2050 * original write request. There is no such thing as a
2051 * successful short write, so if the request was successful
2052 * we can just set it to the originally-requested length.
2054 if (!obj_request->result)
2055 obj_request->xferred = obj_request->length;
2057 /* Finish up with the normal image object callback */
2059 rbd_img_obj_callback(obj_request);
2063 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2065 struct rbd_obj_request *orig_request;
2066 struct ceph_osd_request *osd_req;
2067 struct ceph_osd_client *osdc;
2068 struct rbd_device *rbd_dev;
2069 struct page **pages;
2074 rbd_assert(img_request_child_test(img_request));
2076 /* First get what we need from the image request */
2078 pages = img_request->copyup_pages;
2079 rbd_assert(pages != NULL);
2080 img_request->copyup_pages = NULL;
2082 orig_request = img_request->obj_request;
2083 rbd_assert(orig_request != NULL);
2084 rbd_assert(orig_request->type == OBJ_REQUEST_BIO);
2085 result = img_request->result;
2086 obj_size = img_request->length;
2087 xferred = img_request->xferred;
2089 rbd_dev = img_request->rbd_dev;
2090 rbd_assert(rbd_dev);
2091 rbd_assert(obj_size == (u64)1 << rbd_dev->header.obj_order);
2093 rbd_img_request_put(img_request);
2098 /* Allocate the new copyup osd request for the original request */
2101 rbd_assert(!orig_request->osd_req);
2102 osd_req = rbd_osd_req_create_copyup(orig_request);
2105 orig_request->osd_req = osd_req;
2106 orig_request->copyup_pages = pages;
2108 /* Initialize the copyup op */
2110 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2111 osd_req_op_cls_request_data_pages(osd_req, 0, pages, obj_size, 0,
2114 /* Then the original write request op */
2116 osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE,
2117 orig_request->offset,
2118 orig_request->length, 0, 0);
2119 osd_req_op_extent_osd_data_bio(osd_req, 1, orig_request->bio_list,
2120 orig_request->length);
2122 rbd_osd_req_format_write(orig_request);
2124 /* All set, send it off. */
2126 orig_request->callback = rbd_img_obj_copyup_callback;
2127 osdc = &rbd_dev->rbd_client->client->osdc;
2128 result = rbd_obj_request_submit(osdc, orig_request);
2132 /* Record the error code and complete the request */
2134 orig_request->result = result;
2135 orig_request->xferred = 0;
2136 obj_request_done_set(orig_request);
2137 rbd_obj_request_complete(orig_request);
2141 * Read from the parent image the range of data that covers the
2142 * entire target of the given object request. This is used for
2143 * satisfying a layered image write request when the target of an
2144 * object request from the image request does not exist.
2146 * A page array big enough to hold the returned data is allocated
2147 * and supplied to rbd_img_request_fill() as the "data descriptor."
2148 * When the read completes, this page array will be transferred to
2149 * the original object request for the copyup operation.
2151 * If an error occurs, record it as the result of the original
2152 * object request and mark it done so it gets completed.
2154 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2156 struct rbd_img_request *img_request = NULL;
2157 struct rbd_img_request *parent_request = NULL;
2158 struct rbd_device *rbd_dev;
2161 struct page **pages = NULL;
2165 rbd_assert(obj_request_img_data_test(obj_request));
2166 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2168 img_request = obj_request->img_request;
2169 rbd_assert(img_request != NULL);
2170 rbd_dev = img_request->rbd_dev;
2171 rbd_assert(rbd_dev->parent != NULL);
2174 * First things first. The original osd request is of no
2175 * use to use any more, we'll need a new one that can hold
2176 * the two ops in a copyup request. We'll get that later,
2177 * but for now we can release the old one.
2179 rbd_osd_req_destroy(obj_request->osd_req);
2180 obj_request->osd_req = NULL;
2183 * Determine the byte range covered by the object in the
2184 * child image to which the original request was to be sent.
2186 img_offset = obj_request->img_offset - obj_request->offset;
2187 length = (u64)1 << rbd_dev->header.obj_order;
2190 * There is no defined parent data beyond the parent
2191 * overlap, so limit what we read at that boundary if
2194 if (img_offset + length > rbd_dev->parent_overlap) {
2195 rbd_assert(img_offset < rbd_dev->parent_overlap);
2196 length = rbd_dev->parent_overlap - img_offset;
2200 * Allocate a page array big enough to receive the data read
2203 page_count = (u32)calc_pages_for(0, length);
2204 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2205 if (IS_ERR(pages)) {
2206 result = PTR_ERR(pages);
2212 parent_request = rbd_img_request_create(rbd_dev->parent,
2215 if (!parent_request)
2217 rbd_obj_request_get(obj_request);
2218 parent_request->obj_request = obj_request;
2220 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2223 parent_request->copyup_pages = pages;
2225 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2226 result = rbd_img_request_submit(parent_request);
2230 parent_request->copyup_pages = NULL;
2231 parent_request->obj_request = NULL;
2232 rbd_obj_request_put(obj_request);
2235 ceph_release_page_vector(pages, page_count);
2237 rbd_img_request_put(parent_request);
2238 obj_request->result = result;
2239 obj_request->xferred = 0;
2240 obj_request_done_set(obj_request);
2245 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2247 struct rbd_obj_request *orig_request;
2250 rbd_assert(!obj_request_img_data_test(obj_request));
2253 * All we need from the object request is the original
2254 * request and the result of the STAT op. Grab those, then
2255 * we're done with the request.
2257 orig_request = obj_request->obj_request;
2258 obj_request->obj_request = NULL;
2259 rbd_assert(orig_request);
2260 rbd_assert(orig_request->img_request);
2262 result = obj_request->result;
2263 obj_request->result = 0;
2265 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2266 obj_request, orig_request, result,
2267 obj_request->xferred, obj_request->length);
2268 rbd_obj_request_put(obj_request);
2270 rbd_assert(orig_request);
2271 rbd_assert(orig_request->img_request);
2274 * Our only purpose here is to determine whether the object
2275 * exists, and we don't want to treat the non-existence as
2276 * an error. If something else comes back, transfer the
2277 * error to the original request and complete it now.
2280 obj_request_existence_set(orig_request, true);
2281 } else if (result == -ENOENT) {
2282 obj_request_existence_set(orig_request, false);
2283 } else if (result) {
2284 orig_request->result = result;
2289 * Resubmit the original request now that we have recorded
2290 * whether the target object exists.
2292 orig_request->result = rbd_img_obj_request_submit(orig_request);
2294 if (orig_request->result)
2295 rbd_obj_request_complete(orig_request);
2296 rbd_obj_request_put(orig_request);
2299 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2301 struct rbd_obj_request *stat_request;
2302 struct rbd_device *rbd_dev;
2303 struct ceph_osd_client *osdc;
2304 struct page **pages = NULL;
2310 * The response data for a STAT call consists of:
2317 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2318 page_count = (u32)calc_pages_for(0, size);
2319 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2321 return PTR_ERR(pages);
2324 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2329 rbd_obj_request_get(obj_request);
2330 stat_request->obj_request = obj_request;
2331 stat_request->pages = pages;
2332 stat_request->page_count = page_count;
2334 rbd_assert(obj_request->img_request);
2335 rbd_dev = obj_request->img_request->rbd_dev;
2336 stat_request->osd_req = rbd_osd_req_create(rbd_dev, false,
2338 if (!stat_request->osd_req)
2340 stat_request->callback = rbd_img_obj_exists_callback;
2342 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT);
2343 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2345 rbd_osd_req_format_read(stat_request);
2347 osdc = &rbd_dev->rbd_client->client->osdc;
2348 ret = rbd_obj_request_submit(osdc, stat_request);
2351 rbd_obj_request_put(obj_request);
2356 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2358 struct rbd_img_request *img_request;
2359 struct rbd_device *rbd_dev;
2362 rbd_assert(obj_request_img_data_test(obj_request));
2364 img_request = obj_request->img_request;
2365 rbd_assert(img_request);
2366 rbd_dev = img_request->rbd_dev;
2369 * Only writes to layered images need special handling.
2370 * Reads and non-layered writes are simple object requests.
2371 * Layered writes that start beyond the end of the overlap
2372 * with the parent have no parent data, so they too are
2373 * simple object requests. Finally, if the target object is
2374 * known to already exist, its parent data has already been
2375 * copied, so a write to the object can also be handled as a
2376 * simple object request.
2378 if (!img_request_write_test(img_request) ||
2379 !img_request_layered_test(img_request) ||
2380 rbd_dev->parent_overlap <= obj_request->img_offset ||
2381 ((known = obj_request_known_test(obj_request)) &&
2382 obj_request_exists_test(obj_request))) {
2384 struct rbd_device *rbd_dev;
2385 struct ceph_osd_client *osdc;
2387 rbd_dev = obj_request->img_request->rbd_dev;
2388 osdc = &rbd_dev->rbd_client->client->osdc;
2390 return rbd_obj_request_submit(osdc, obj_request);
2394 * It's a layered write. The target object might exist but
2395 * we may not know that yet. If we know it doesn't exist,
2396 * start by reading the data for the full target object from
2397 * the parent so we can use it for a copyup to the target.
2400 return rbd_img_obj_parent_read_full(obj_request);
2402 /* We don't know whether the target exists. Go find out. */
2404 return rbd_img_obj_exists_submit(obj_request);
2407 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2409 struct rbd_obj_request *obj_request;
2410 struct rbd_obj_request *next_obj_request;
2412 dout("%s: img %p\n", __func__, img_request);
2413 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2416 ret = rbd_img_obj_request_submit(obj_request);
2424 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2426 struct rbd_obj_request *obj_request;
2427 struct rbd_device *rbd_dev;
2430 rbd_assert(img_request_child_test(img_request));
2432 obj_request = img_request->obj_request;
2433 rbd_assert(obj_request);
2434 rbd_assert(obj_request->img_request);
2436 obj_request->result = img_request->result;
2437 if (obj_request->result)
2441 * We need to zero anything beyond the parent overlap
2442 * boundary. Since rbd_img_obj_request_read_callback()
2443 * will zero anything beyond the end of a short read, an
2444 * easy way to do this is to pretend the data from the
2445 * parent came up short--ending at the overlap boundary.
2447 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
2448 obj_end = obj_request->img_offset + obj_request->length;
2449 rbd_dev = obj_request->img_request->rbd_dev;
2450 if (obj_end > rbd_dev->parent_overlap) {
2453 if (obj_request->img_offset < rbd_dev->parent_overlap)
2454 xferred = rbd_dev->parent_overlap -
2455 obj_request->img_offset;
2457 obj_request->xferred = min(img_request->xferred, xferred);
2459 obj_request->xferred = img_request->xferred;
2462 rbd_img_obj_request_read_callback(obj_request);
2463 rbd_obj_request_complete(obj_request);
2466 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
2468 struct rbd_device *rbd_dev;
2469 struct rbd_img_request *img_request;
2472 rbd_assert(obj_request_img_data_test(obj_request));
2473 rbd_assert(obj_request->img_request != NULL);
2474 rbd_assert(obj_request->result == (s32) -ENOENT);
2475 rbd_assert(obj_request->type == OBJ_REQUEST_BIO);
2477 rbd_dev = obj_request->img_request->rbd_dev;
2478 rbd_assert(rbd_dev->parent != NULL);
2479 /* rbd_read_finish(obj_request, obj_request->length); */
2480 img_request = rbd_img_request_create(rbd_dev->parent,
2481 obj_request->img_offset,
2482 obj_request->length,
2488 rbd_obj_request_get(obj_request);
2489 img_request->obj_request = obj_request;
2491 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2492 obj_request->bio_list);
2496 img_request->callback = rbd_img_parent_read_callback;
2497 result = rbd_img_request_submit(img_request);
2504 rbd_img_request_put(img_request);
2505 obj_request->result = result;
2506 obj_request->xferred = 0;
2507 obj_request_done_set(obj_request);
2510 static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
2512 struct rbd_obj_request *obj_request;
2513 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2516 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2517 OBJ_REQUEST_NODATA);
2522 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2523 if (!obj_request->osd_req)
2525 obj_request->callback = rbd_obj_request_put;
2527 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
2529 rbd_osd_req_format_read(obj_request);
2531 ret = rbd_obj_request_submit(osdc, obj_request);
2534 rbd_obj_request_put(obj_request);
2539 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
2541 struct rbd_device *rbd_dev = (struct rbd_device *)data;
2546 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
2547 rbd_dev->header_name, (unsigned long long)notify_id,
2548 (unsigned int)opcode);
2549 (void)rbd_dev_refresh(rbd_dev);
2551 rbd_obj_notify_ack(rbd_dev, notify_id);
2555 * Request sync osd watch/unwatch. The value of "start" determines
2556 * whether a watch request is being initiated or torn down.
2558 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start)
2560 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2561 struct rbd_obj_request *obj_request;
2564 rbd_assert(start ^ !!rbd_dev->watch_event);
2565 rbd_assert(start ^ !!rbd_dev->watch_request);
2568 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
2569 &rbd_dev->watch_event);
2572 rbd_assert(rbd_dev->watch_event != NULL);
2576 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
2577 OBJ_REQUEST_NODATA);
2581 obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, obj_request);
2582 if (!obj_request->osd_req)
2586 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
2588 ceph_osdc_unregister_linger_request(osdc,
2589 rbd_dev->watch_request->osd_req);
2591 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
2592 rbd_dev->watch_event->cookie, 0, start);
2593 rbd_osd_req_format_write(obj_request);
2595 ret = rbd_obj_request_submit(osdc, obj_request);
2598 ret = rbd_obj_request_wait(obj_request);
2601 ret = obj_request->result;
2606 * A watch request is set to linger, so the underlying osd
2607 * request won't go away until we unregister it. We retain
2608 * a pointer to the object request during that time (in
2609 * rbd_dev->watch_request), so we'll keep a reference to
2610 * it. We'll drop that reference (below) after we've
2614 rbd_dev->watch_request = obj_request;
2619 /* We have successfully torn down the watch request */
2621 rbd_obj_request_put(rbd_dev->watch_request);
2622 rbd_dev->watch_request = NULL;
2624 /* Cancel the event if we're tearing down, or on error */
2625 ceph_osdc_cancel_event(rbd_dev->watch_event);
2626 rbd_dev->watch_event = NULL;
2628 rbd_obj_request_put(obj_request);
2634 * Synchronous osd object method call. Returns the number of bytes
2635 * returned in the outbound buffer, or a negative error code.
2637 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
2638 const char *object_name,
2639 const char *class_name,
2640 const char *method_name,
2641 const void *outbound,
2642 size_t outbound_size,
2644 size_t inbound_size)
2646 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2647 struct rbd_obj_request *obj_request;
2648 struct page **pages;
2653 * Method calls are ultimately read operations. The result
2654 * should placed into the inbound buffer provided. They
2655 * also supply outbound data--parameters for the object
2656 * method. Currently if this is present it will be a
2659 page_count = (u32)calc_pages_for(0, inbound_size);
2660 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2662 return PTR_ERR(pages);
2665 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
2670 obj_request->pages = pages;
2671 obj_request->page_count = page_count;
2673 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2674 if (!obj_request->osd_req)
2677 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
2678 class_name, method_name);
2679 if (outbound_size) {
2680 struct ceph_pagelist *pagelist;
2682 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
2686 ceph_pagelist_init(pagelist);
2687 ceph_pagelist_append(pagelist, outbound, outbound_size);
2688 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
2691 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
2692 obj_request->pages, inbound_size,
2694 rbd_osd_req_format_read(obj_request);
2696 ret = rbd_obj_request_submit(osdc, obj_request);
2699 ret = rbd_obj_request_wait(obj_request);
2703 ret = obj_request->result;
2707 rbd_assert(obj_request->xferred < (u64)INT_MAX);
2708 ret = (int)obj_request->xferred;
2709 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
2712 rbd_obj_request_put(obj_request);
2714 ceph_release_page_vector(pages, page_count);
2719 static void rbd_request_fn(struct request_queue *q)
2720 __releases(q->queue_lock) __acquires(q->queue_lock)
2722 struct rbd_device *rbd_dev = q->queuedata;
2723 bool read_only = rbd_dev->mapping.read_only;
2727 while ((rq = blk_fetch_request(q))) {
2728 bool write_request = rq_data_dir(rq) == WRITE;
2729 struct rbd_img_request *img_request;
2733 /* Ignore any non-FS requests that filter through. */
2735 if (rq->cmd_type != REQ_TYPE_FS) {
2736 dout("%s: non-fs request type %d\n", __func__,
2737 (int) rq->cmd_type);
2738 __blk_end_request_all(rq, 0);
2742 /* Ignore/skip any zero-length requests */
2744 offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
2745 length = (u64) blk_rq_bytes(rq);
2748 dout("%s: zero-length request\n", __func__);
2749 __blk_end_request_all(rq, 0);
2753 spin_unlock_irq(q->queue_lock);
2755 /* Disallow writes to a read-only device */
2757 if (write_request) {
2761 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
2765 * Quit early if the mapped snapshot no longer
2766 * exists. It's still possible the snapshot will
2767 * have disappeared by the time our request arrives
2768 * at the osd, but there's no sense in sending it if
2771 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
2772 dout("request for non-existent snapshot");
2773 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
2779 if (offset && length > U64_MAX - offset + 1) {
2780 rbd_warn(rbd_dev, "bad request range (%llu~%llu)\n",
2782 goto end_request; /* Shouldn't happen */
2786 img_request = rbd_img_request_create(rbd_dev, offset, length,
2787 write_request, false);
2791 img_request->rq = rq;
2793 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
2796 result = rbd_img_request_submit(img_request);
2798 rbd_img_request_put(img_request);
2800 spin_lock_irq(q->queue_lock);
2802 rbd_warn(rbd_dev, "%s %llx at %llx result %d\n",
2803 write_request ? "write" : "read",
2804 length, offset, result);
2806 __blk_end_request_all(rq, result);
2812 * a queue callback. Makes sure that we don't create a bio that spans across
2813 * multiple osd objects. One exception would be with a single page bios,
2814 * which we handle later at bio_chain_clone_range()
2816 static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2817 struct bio_vec *bvec)
2819 struct rbd_device *rbd_dev = q->queuedata;
2820 sector_t sector_offset;
2821 sector_t sectors_per_obj;
2822 sector_t obj_sector_offset;
2826 * Find how far into its rbd object the partition-relative
2827 * bio start sector is to offset relative to the enclosing
2830 sector_offset = get_start_sect(bmd->bi_bdev) + bmd->bi_sector;
2831 sectors_per_obj = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT);
2832 obj_sector_offset = sector_offset & (sectors_per_obj - 1);
2835 * Compute the number of bytes from that offset to the end
2836 * of the object. Account for what's already used by the bio.
2838 ret = (int) (sectors_per_obj - obj_sector_offset) << SECTOR_SHIFT;
2839 if (ret > bmd->bi_size)
2840 ret -= bmd->bi_size;
2845 * Don't send back more than was asked for. And if the bio
2846 * was empty, let the whole thing through because: "Note
2847 * that a block device *must* allow a single page to be
2848 * added to an empty bio."
2850 rbd_assert(bvec->bv_len <= PAGE_SIZE);
2851 if (ret > (int) bvec->bv_len || !bmd->bi_size)
2852 ret = (int) bvec->bv_len;
2857 static void rbd_free_disk(struct rbd_device *rbd_dev)
2859 struct gendisk *disk = rbd_dev->disk;
2864 rbd_dev->disk = NULL;
2865 if (disk->flags & GENHD_FL_UP) {
2868 blk_cleanup_queue(disk->queue);
2873 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
2874 const char *object_name,
2875 u64 offset, u64 length, void *buf)
2878 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2879 struct rbd_obj_request *obj_request;
2880 struct page **pages = NULL;
2885 page_count = (u32) calc_pages_for(offset, length);
2886 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2888 ret = PTR_ERR(pages);
2891 obj_request = rbd_obj_request_create(object_name, offset, length,
2896 obj_request->pages = pages;
2897 obj_request->page_count = page_count;
2899 obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
2900 if (!obj_request->osd_req)
2903 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
2904 offset, length, 0, 0);
2905 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
2907 obj_request->length,
2908 obj_request->offset & ~PAGE_MASK,
2910 rbd_osd_req_format_read(obj_request);
2912 ret = rbd_obj_request_submit(osdc, obj_request);
2915 ret = rbd_obj_request_wait(obj_request);
2919 ret = obj_request->result;
2923 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
2924 size = (size_t) obj_request->xferred;
2925 ceph_copy_from_page_vector(pages, buf, 0, size);
2926 rbd_assert(size <= (size_t)INT_MAX);
2930 rbd_obj_request_put(obj_request);
2932 ceph_release_page_vector(pages, page_count);
2938 * Read the complete header for the given rbd device.
2940 * Returns a pointer to a dynamically-allocated buffer containing
2941 * the complete and validated header. Caller can pass the address
2942 * of a variable that will be filled in with the version of the
2943 * header object at the time it was read.
2945 * Returns a pointer-coded errno if a failure occurs.
2947 static struct rbd_image_header_ondisk *
2948 rbd_dev_v1_header_read(struct rbd_device *rbd_dev)
2950 struct rbd_image_header_ondisk *ondisk = NULL;
2957 * The complete header will include an array of its 64-bit
2958 * snapshot ids, followed by the names of those snapshots as
2959 * a contiguous block of NUL-terminated strings. Note that
2960 * the number of snapshots could change by the time we read
2961 * it in, in which case we re-read it.
2968 size = sizeof (*ondisk);
2969 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
2971 ondisk = kmalloc(size, GFP_KERNEL);
2973 return ERR_PTR(-ENOMEM);
2975 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
2979 if ((size_t)ret < size) {
2981 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
2985 if (!rbd_dev_ondisk_valid(ondisk)) {
2987 rbd_warn(rbd_dev, "invalid header");
2991 names_size = le64_to_cpu(ondisk->snap_names_len);
2992 want_count = snap_count;
2993 snap_count = le32_to_cpu(ondisk->snap_count);
2994 } while (snap_count != want_count);
3001 return ERR_PTR(ret);
3005 * reload the ondisk the header
3007 static int rbd_read_header(struct rbd_device *rbd_dev,
3008 struct rbd_image_header *header)
3010 struct rbd_image_header_ondisk *ondisk;
3013 ondisk = rbd_dev_v1_header_read(rbd_dev);
3015 return PTR_ERR(ondisk);
3016 ret = rbd_header_from_disk(header, ondisk);
3022 static void rbd_remove_all_snaps(struct rbd_device *rbd_dev)
3024 struct rbd_snap *snap;
3025 struct rbd_snap *next;
3027 list_for_each_entry_safe(snap, next, &rbd_dev->snaps, node) {
3028 list_del(&snap->node);
3029 rbd_snap_destroy(snap);
3033 static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
3035 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
3038 if (rbd_dev->mapping.size != rbd_dev->header.image_size) {
3041 rbd_dev->mapping.size = rbd_dev->header.image_size;
3042 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3043 dout("setting size to %llu sectors", (unsigned long long)size);
3044 set_capacity(rbd_dev->disk, size);
3049 * only read the first part of the ondisk header, without the snaps info
3051 static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev)
3054 struct rbd_image_header h;
3056 ret = rbd_read_header(rbd_dev, &h);
3060 down_write(&rbd_dev->header_rwsem);
3062 /* Update image size, and check for resize of mapped image */
3063 rbd_dev->header.image_size = h.image_size;
3064 rbd_update_mapping_size(rbd_dev);
3066 /* rbd_dev->header.object_prefix shouldn't change */
3067 kfree(rbd_dev->header.snap_sizes);
3068 kfree(rbd_dev->header.snap_names);
3069 /* osd requests may still refer to snapc */
3070 ceph_put_snap_context(rbd_dev->header.snapc);
3072 rbd_dev->header.image_size = h.image_size;
3073 rbd_dev->header.snapc = h.snapc;
3074 rbd_dev->header.snap_names = h.snap_names;
3075 rbd_dev->header.snap_sizes = h.snap_sizes;
3076 /* Free the extra copy of the object prefix */
3077 if (strcmp(rbd_dev->header.object_prefix, h.object_prefix))
3078 rbd_warn(rbd_dev, "object prefix changed (ignoring)");
3079 kfree(h.object_prefix);
3081 ret = rbd_dev_snaps_update(rbd_dev);
3083 up_write(&rbd_dev->header_rwsem);
3088 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3093 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
3094 image_size = rbd_dev->header.image_size;
3095 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3096 if (rbd_dev->image_format == 1)
3097 ret = rbd_dev_v1_refresh(rbd_dev);
3099 ret = rbd_dev_v2_refresh(rbd_dev);
3100 mutex_unlock(&ctl_mutex);
3102 rbd_warn(rbd_dev, "got notification but failed to "
3103 " update snaps: %d\n", ret);
3104 if (image_size != rbd_dev->header.image_size)
3105 revalidate_disk(rbd_dev->disk);
3110 static int rbd_init_disk(struct rbd_device *rbd_dev)
3112 struct gendisk *disk;
3113 struct request_queue *q;
3116 /* create gendisk info */
3117 disk = alloc_disk(RBD_MINORS_PER_MAJOR);
3121 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3123 disk->major = rbd_dev->major;
3124 disk->first_minor = 0;
3125 disk->fops = &rbd_bd_ops;
3126 disk->private_data = rbd_dev;
3128 q = blk_init_queue(rbd_request_fn, &rbd_dev->lock);
3132 /* We use the default size, but let's be explicit about it. */
3133 blk_queue_physical_block_size(q, SECTOR_SIZE);
3135 /* set io sizes to object size */
3136 segment_size = rbd_obj_bytes(&rbd_dev->header);
3137 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3138 blk_queue_max_segment_size(q, segment_size);
3139 blk_queue_io_min(q, segment_size);
3140 blk_queue_io_opt(q, segment_size);
3142 blk_queue_merge_bvec(q, rbd_merge_bvec);
3145 q->queuedata = rbd_dev;
3147 rbd_dev->disk = disk;
3160 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3162 return container_of(dev, struct rbd_device, dev);
3165 static ssize_t rbd_size_show(struct device *dev,
3166 struct device_attribute *attr, char *buf)
3168 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3170 return sprintf(buf, "%llu\n",
3171 (unsigned long long)rbd_dev->mapping.size);
3175 * Note this shows the features for whatever's mapped, which is not
3176 * necessarily the base image.
3178 static ssize_t rbd_features_show(struct device *dev,
3179 struct device_attribute *attr, char *buf)
3181 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3183 return sprintf(buf, "0x%016llx\n",
3184 (unsigned long long)rbd_dev->mapping.features);
3187 static ssize_t rbd_major_show(struct device *dev,
3188 struct device_attribute *attr, char *buf)
3190 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3193 return sprintf(buf, "%d\n", rbd_dev->major);
3195 return sprintf(buf, "(none)\n");
3199 static ssize_t rbd_client_id_show(struct device *dev,
3200 struct device_attribute *attr, char *buf)
3202 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3204 return sprintf(buf, "client%lld\n",
3205 ceph_client_id(rbd_dev->rbd_client->client));
3208 static ssize_t rbd_pool_show(struct device *dev,
3209 struct device_attribute *attr, char *buf)
3211 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3213 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3216 static ssize_t rbd_pool_id_show(struct device *dev,
3217 struct device_attribute *attr, char *buf)
3219 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3221 return sprintf(buf, "%llu\n",
3222 (unsigned long long) rbd_dev->spec->pool_id);
3225 static ssize_t rbd_name_show(struct device *dev,
3226 struct device_attribute *attr, char *buf)
3228 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3230 if (rbd_dev->spec->image_name)
3231 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3233 return sprintf(buf, "(unknown)\n");
3236 static ssize_t rbd_image_id_show(struct device *dev,
3237 struct device_attribute *attr, char *buf)
3239 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3241 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3245 * Shows the name of the currently-mapped snapshot (or
3246 * RBD_SNAP_HEAD_NAME for the base image).
3248 static ssize_t rbd_snap_show(struct device *dev,
3249 struct device_attribute *attr,
3252 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3254 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3258 * For an rbd v2 image, shows the pool id, image id, and snapshot id
3259 * for the parent image. If there is no parent, simply shows
3260 * "(no parent image)".
3262 static ssize_t rbd_parent_show(struct device *dev,
3263 struct device_attribute *attr,
3266 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3267 struct rbd_spec *spec = rbd_dev->parent_spec;
3272 return sprintf(buf, "(no parent image)\n");
3274 count = sprintf(bufp, "pool_id %llu\npool_name %s\n",
3275 (unsigned long long) spec->pool_id, spec->pool_name);
3280 count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id,
3281 spec->image_name ? spec->image_name : "(unknown)");
3286 count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n",
3287 (unsigned long long) spec->snap_id, spec->snap_name);
3292 count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap);
3297 return (ssize_t) (bufp - buf);
3300 static ssize_t rbd_image_refresh(struct device *dev,
3301 struct device_attribute *attr,
3305 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3308 ret = rbd_dev_refresh(rbd_dev);
3310 return ret < 0 ? ret : size;
3313 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3314 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3315 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3316 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3317 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3318 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3319 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3320 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3321 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3322 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3323 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3325 static struct attribute *rbd_attrs[] = {
3326 &dev_attr_size.attr,
3327 &dev_attr_features.attr,
3328 &dev_attr_major.attr,
3329 &dev_attr_client_id.attr,
3330 &dev_attr_pool.attr,
3331 &dev_attr_pool_id.attr,
3332 &dev_attr_name.attr,
3333 &dev_attr_image_id.attr,
3334 &dev_attr_current_snap.attr,
3335 &dev_attr_parent.attr,
3336 &dev_attr_refresh.attr,
3340 static struct attribute_group rbd_attr_group = {
3344 static const struct attribute_group *rbd_attr_groups[] = {
3349 static void rbd_sysfs_dev_release(struct device *dev)
3353 static struct device_type rbd_device_type = {
3355 .groups = rbd_attr_groups,
3356 .release = rbd_sysfs_dev_release,
3359 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
3361 kref_get(&spec->kref);
3366 static void rbd_spec_free(struct kref *kref);
3367 static void rbd_spec_put(struct rbd_spec *spec)
3370 kref_put(&spec->kref, rbd_spec_free);
3373 static struct rbd_spec *rbd_spec_alloc(void)
3375 struct rbd_spec *spec;
3377 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
3380 kref_init(&spec->kref);
3385 static void rbd_spec_free(struct kref *kref)
3387 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
3389 kfree(spec->pool_name);
3390 kfree(spec->image_id);
3391 kfree(spec->image_name);
3392 kfree(spec->snap_name);
3396 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
3397 struct rbd_spec *spec)
3399 struct rbd_device *rbd_dev;
3401 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
3405 spin_lock_init(&rbd_dev->lock);
3407 INIT_LIST_HEAD(&rbd_dev->node);
3408 INIT_LIST_HEAD(&rbd_dev->snaps);
3409 init_rwsem(&rbd_dev->header_rwsem);
3411 rbd_dev->spec = spec;
3412 rbd_dev->rbd_client = rbdc;
3414 /* Initialize the layout used for all rbd requests */
3416 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3417 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
3418 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
3419 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
3424 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
3426 rbd_put_client(rbd_dev->rbd_client);
3427 rbd_spec_put(rbd_dev->spec);
3431 static void rbd_snap_destroy(struct rbd_snap *snap)
3437 static struct rbd_snap *rbd_snap_create(struct rbd_device *rbd_dev,
3438 const char *snap_name,
3439 u64 snap_id, u64 snap_size,
3442 struct rbd_snap *snap;
3444 snap = kzalloc(sizeof (*snap), GFP_KERNEL);
3446 return ERR_PTR(-ENOMEM);
3448 snap->name = snap_name;
3450 snap->size = snap_size;
3451 snap->features = snap_features;
3457 * Returns a dynamically-allocated snapshot name if successful, or a
3458 * pointer-coded error otherwise.
3460 static const char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev,
3461 u64 snap_id, u64 *snap_size, u64 *snap_features)
3463 const char *snap_name;
3466 which = rbd_dev_snap_index(rbd_dev, snap_id);
3467 if (which == BAD_SNAP_INDEX)
3468 return ERR_PTR(-ENOENT);
3469 snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
3471 return ERR_PTR(-ENOMEM);
3473 *snap_size = rbd_dev->header.snap_sizes[which];
3474 *snap_features = 0; /* No features for v1 */
3480 * Get the size and object order for an image snapshot, or if
3481 * snap_id is CEPH_NOSNAP, gets this information for the base
3484 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
3485 u8 *order, u64 *snap_size)
3487 __le64 snapid = cpu_to_le64(snap_id);
3492 } __attribute__ ((packed)) size_buf = { 0 };
3494 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3496 &snapid, sizeof (snapid),
3497 &size_buf, sizeof (size_buf));
3498 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3501 if (ret < sizeof (size_buf))
3505 *order = size_buf.order;
3506 *snap_size = le64_to_cpu(size_buf.size);
3508 dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n",
3509 (unsigned long long)snap_id, (unsigned int)*order,
3510 (unsigned long long)*snap_size);
3515 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
3517 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
3518 &rbd_dev->header.obj_order,
3519 &rbd_dev->header.image_size);
3522 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
3528 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
3532 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3533 "rbd", "get_object_prefix", NULL, 0,
3534 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
3535 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3540 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
3541 p + ret, NULL, GFP_NOIO);
3544 if (IS_ERR(rbd_dev->header.object_prefix)) {
3545 ret = PTR_ERR(rbd_dev->header.object_prefix);
3546 rbd_dev->header.object_prefix = NULL;
3548 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
3556 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
3559 __le64 snapid = cpu_to_le64(snap_id);
3563 } __attribute__ ((packed)) features_buf = { 0 };
3567 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3568 "rbd", "get_features",
3569 &snapid, sizeof (snapid),
3570 &features_buf, sizeof (features_buf));
3571 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3574 if (ret < sizeof (features_buf))
3577 incompat = le64_to_cpu(features_buf.incompat);
3578 if (incompat & ~RBD_FEATURES_SUPPORTED)
3581 *snap_features = le64_to_cpu(features_buf.features);
3583 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
3584 (unsigned long long)snap_id,
3585 (unsigned long long)*snap_features,
3586 (unsigned long long)le64_to_cpu(features_buf.incompat));
3591 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
3593 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
3594 &rbd_dev->header.features);
3597 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
3599 struct rbd_spec *parent_spec;
3601 void *reply_buf = NULL;
3609 parent_spec = rbd_spec_alloc();
3613 size = sizeof (__le64) + /* pool_id */
3614 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
3615 sizeof (__le64) + /* snap_id */
3616 sizeof (__le64); /* overlap */
3617 reply_buf = kmalloc(size, GFP_KERNEL);
3623 snapid = cpu_to_le64(CEPH_NOSNAP);
3624 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3625 "rbd", "get_parent",
3626 &snapid, sizeof (snapid),
3628 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3633 end = reply_buf + ret;
3635 ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err);
3636 if (parent_spec->pool_id == CEPH_NOPOOL)
3637 goto out; /* No parent? No problem. */
3639 /* The ceph file layout needs to fit pool id in 32 bits */
3642 if (parent_spec->pool_id > (u64)U32_MAX) {
3643 rbd_warn(NULL, "parent pool id too large (%llu > %u)\n",
3644 (unsigned long long)parent_spec->pool_id, U32_MAX);
3648 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3649 if (IS_ERR(image_id)) {
3650 ret = PTR_ERR(image_id);
3653 parent_spec->image_id = image_id;
3654 ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
3655 ceph_decode_64_safe(&p, end, overlap, out_err);
3657 rbd_dev->parent_overlap = overlap;
3658 rbd_dev->parent_spec = parent_spec;
3659 parent_spec = NULL; /* rbd_dev now owns this */
3664 rbd_spec_put(parent_spec);
3669 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
3673 __le64 stripe_count;
3674 } __attribute__ ((packed)) striping_info_buf = { 0 };
3675 size_t size = sizeof (striping_info_buf);
3682 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3683 "rbd", "get_stripe_unit_count", NULL, 0,
3684 (char *)&striping_info_buf, size);
3685 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3692 * We don't actually support the "fancy striping" feature
3693 * (STRIPINGV2) yet, but if the striping sizes are the
3694 * defaults the behavior is the same as before. So find
3695 * out, and only fail if the image has non-default values.
3698 obj_size = (u64)1 << rbd_dev->header.obj_order;
3699 p = &striping_info_buf;
3700 stripe_unit = ceph_decode_64(&p);
3701 if (stripe_unit != obj_size) {
3702 rbd_warn(rbd_dev, "unsupported stripe unit "
3703 "(got %llu want %llu)",
3704 stripe_unit, obj_size);
3707 stripe_count = ceph_decode_64(&p);
3708 if (stripe_count != 1) {
3709 rbd_warn(rbd_dev, "unsupported stripe count "
3710 "(got %llu want 1)", stripe_count);
3713 rbd_dev->header.stripe_unit = stripe_unit;
3714 rbd_dev->header.stripe_count = stripe_count;
3719 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
3721 size_t image_id_size;
3726 void *reply_buf = NULL;
3728 char *image_name = NULL;
3731 rbd_assert(!rbd_dev->spec->image_name);
3733 len = strlen(rbd_dev->spec->image_id);
3734 image_id_size = sizeof (__le32) + len;
3735 image_id = kmalloc(image_id_size, GFP_KERNEL);
3740 end = image_id + image_id_size;
3741 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
3743 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
3744 reply_buf = kmalloc(size, GFP_KERNEL);
3748 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
3749 "rbd", "dir_get_name",
3750 image_id, image_id_size,
3755 end = reply_buf + ret;
3757 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
3758 if (IS_ERR(image_name))
3761 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
3770 * When an rbd image has a parent image, it is identified by the
3771 * pool, image, and snapshot ids (not names). This function fills
3772 * in the names for those ids. (It's OK if we can't figure out the
3773 * name for an image id, but the pool and snapshot ids should always
3774 * exist and have names.) All names in an rbd spec are dynamically
3777 * When an image being mapped (not a parent) is probed, we have the
3778 * pool name and pool id, image name and image id, and the snapshot
3779 * name. The only thing we're missing is the snapshot id.
3781 * The set of snapshots for an image is not known until they have
3782 * been read by rbd_dev_snaps_update(), so we can't completely fill
3783 * in this information until after that has been called.
3785 static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
3787 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3788 struct rbd_spec *spec = rbd_dev->spec;
3789 const char *pool_name;
3790 const char *image_name;
3791 const char *snap_name;
3795 * An image being mapped will have the pool name (etc.), but
3796 * we need to look up the snapshot id.
3798 if (spec->pool_name) {
3799 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
3800 struct rbd_snap *snap;
3802 snap = snap_by_name(rbd_dev, spec->snap_name);
3805 spec->snap_id = snap->id;
3807 spec->snap_id = CEPH_NOSNAP;
3813 /* Get the pool name; we have to make our own copy of this */
3815 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
3817 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
3820 pool_name = kstrdup(pool_name, GFP_KERNEL);
3824 /* Fetch the image name; tolerate failure here */
3826 image_name = rbd_dev_image_name(rbd_dev);
3828 rbd_warn(rbd_dev, "unable to get image name");
3830 /* Look up the snapshot name, and make a copy */
3832 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
3838 spec->pool_name = pool_name;
3839 spec->image_name = image_name;
3840 spec->snap_name = snap_name;
3850 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
3859 struct ceph_snap_context *snapc;
3863 * We'll need room for the seq value (maximum snapshot id),
3864 * snapshot count, and array of that many snapshot ids.
3865 * For now we have a fixed upper limit on the number we're
3866 * prepared to receive.
3868 size = sizeof (__le64) + sizeof (__le32) +
3869 RBD_MAX_SNAP_COUNT * sizeof (__le64);
3870 reply_buf = kzalloc(size, GFP_KERNEL);
3874 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3875 "rbd", "get_snapcontext", NULL, 0,
3877 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3882 end = reply_buf + ret;
3884 ceph_decode_64_safe(&p, end, seq, out);
3885 ceph_decode_32_safe(&p, end, snap_count, out);
3888 * Make sure the reported number of snapshot ids wouldn't go
3889 * beyond the end of our buffer. But before checking that,
3890 * make sure the computed size of the snapshot context we
3891 * allocate is representable in a size_t.
3893 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
3898 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
3902 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
3908 for (i = 0; i < snap_count; i++)
3909 snapc->snaps[i] = ceph_decode_64(&p);
3911 rbd_dev->header.snapc = snapc;
3913 dout(" snap context seq = %llu, snap_count = %u\n",
3914 (unsigned long long)seq, (unsigned int)snap_count);
3921 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
3932 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
3933 reply_buf = kmalloc(size, GFP_KERNEL);
3935 return ERR_PTR(-ENOMEM);
3937 snapid = cpu_to_le64(snap_id);
3938 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
3939 "rbd", "get_snapshot_name",
3940 &snapid, sizeof (snapid),
3942 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
3944 snap_name = ERR_PTR(ret);
3949 end = reply_buf + ret;
3950 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
3951 if (IS_ERR(snap_name))
3954 dout(" snap_id 0x%016llx snap_name = %s\n",
3955 (unsigned long long)snap_id, snap_name);
3962 static const char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev,
3963 u64 snap_id, u64 *snap_size, u64 *snap_features)
3967 const char *snap_name;
3970 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
3974 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
3978 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
3979 if (!IS_ERR(snap_name)) {
3981 *snap_features = features;
3986 return ERR_PTR(ret);
3989 static const char *rbd_dev_snap_info(struct rbd_device *rbd_dev,
3990 u64 snap_id, u64 *snap_size, u64 *snap_features)
3992 if (rbd_dev->image_format == 1)
3993 return rbd_dev_v1_snap_info(rbd_dev, snap_id,
3994 snap_size, snap_features);
3995 if (rbd_dev->image_format == 2)
3996 return rbd_dev_v2_snap_info(rbd_dev, snap_id,
3997 snap_size, snap_features);
3998 return ERR_PTR(-EINVAL);
4001 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev)
4005 down_write(&rbd_dev->header_rwsem);
4007 ret = rbd_dev_v2_image_size(rbd_dev);
4010 rbd_update_mapping_size(rbd_dev);
4012 ret = rbd_dev_v2_snap_context(rbd_dev);
4013 dout("rbd_dev_v2_snap_context returned %d\n", ret);
4016 ret = rbd_dev_snaps_update(rbd_dev);
4017 dout("rbd_dev_snaps_update returned %d\n", ret);
4021 up_write(&rbd_dev->header_rwsem);
4027 * Scan the rbd device's current snapshot list and compare it to the
4028 * newly-received snapshot context. Remove any existing snapshots
4029 * not present in the new snapshot context. Add a new snapshot for
4030 * any snaphots in the snapshot context not in the current list.
4031 * And verify there are no changes to snapshots we already know
4034 * Assumes the snapshots in the snapshot context are sorted by
4035 * snapshot id, highest id first. (Snapshots in the rbd_dev's list
4036 * are also maintained in that order.)
4038 * Note that any error occurs while updating the snapshot list
4039 * aborts the update, and the entire list is cleared. The snapshot
4040 * list becomes inconsistent at that point anyway, so it might as
4043 static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
4045 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
4046 const u32 snap_count = snapc->num_snaps;
4047 struct list_head *head = &rbd_dev->snaps;
4048 struct list_head *links = head->next;
4052 dout("%s: snap count is %u\n", __func__, (unsigned int)snap_count);
4053 while (index < snap_count || links != head) {
4055 struct rbd_snap *snap;
4056 const char *snap_name;
4058 u64 snap_features = 0;
4060 snap_id = index < snap_count ? snapc->snaps[index]
4062 snap = links != head ? list_entry(links, struct rbd_snap, node)
4064 rbd_assert(!snap || snap->id != CEPH_NOSNAP);
4066 if (snap_id == CEPH_NOSNAP || (snap && snap->id > snap_id)) {
4067 struct list_head *next = links->next;
4070 * A previously-existing snapshot is not in
4071 * the new snap context.
4073 * If the now-missing snapshot is the one
4074 * the image represents, clear its existence
4075 * flag so we can avoid sending any more
4078 if (rbd_dev->spec->snap_id == snap->id)
4079 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4080 dout("removing %ssnap id %llu\n",
4081 rbd_dev->spec->snap_id == snap->id ?
4083 (unsigned long long)snap->id);
4085 list_del(&snap->node);
4086 rbd_snap_destroy(snap);
4088 /* Done with this list entry; advance */
4094 snap_name = rbd_dev_snap_info(rbd_dev, snap_id,
4095 &snap_size, &snap_features);
4096 if (IS_ERR(snap_name)) {
4097 ret = PTR_ERR(snap_name);
4098 dout("failed to get snap info, error %d\n", ret);
4102 dout("entry %u: snap_id = %llu\n", (unsigned int)snap_count,
4103 (unsigned long long)snap_id);
4104 if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) {
4105 struct rbd_snap *new_snap;
4107 /* We haven't seen this snapshot before */
4109 new_snap = rbd_snap_create(rbd_dev, snap_name,
4110 snap_id, snap_size, snap_features);
4111 if (IS_ERR(new_snap)) {
4112 ret = PTR_ERR(new_snap);
4113 dout(" failed to add dev, error %d\n", ret);
4117 /* New goes before existing, or at end of list */
4119 dout(" added dev%s\n", snap ? "" : " at end\n");
4121 list_add_tail(&new_snap->node, &snap->node);
4123 list_add_tail(&new_snap->node, head);
4125 /* Already have this one */
4127 dout(" already present\n");
4129 rbd_assert(snap->size == snap_size);
4130 rbd_assert(!strcmp(snap->name, snap_name));
4131 rbd_assert(snap->features == snap_features);
4133 /* Done with this list entry; advance */
4135 links = links->next;
4138 /* Advance to the next entry in the snapshot context */
4142 dout("%s: done\n", __func__);
4146 rbd_remove_all_snaps(rbd_dev);
4151 static int rbd_bus_add_dev(struct rbd_device *rbd_dev)
4156 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
4158 dev = &rbd_dev->dev;
4159 dev->bus = &rbd_bus_type;
4160 dev->type = &rbd_device_type;
4161 dev->parent = &rbd_root_dev;
4162 dev->release = rbd_dev_device_release;
4163 dev_set_name(dev, "%d", rbd_dev->dev_id);
4164 ret = device_register(dev);
4166 mutex_unlock(&ctl_mutex);
4171 static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
4173 device_unregister(&rbd_dev->dev);
4176 static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);
4179 * Get a unique rbd identifier for the given new rbd_dev, and add
4180 * the rbd_dev to the global list. The minimum rbd id is 1.
4182 static void rbd_dev_id_get(struct rbd_device *rbd_dev)
4184 rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max);
4186 spin_lock(&rbd_dev_list_lock);
4187 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4188 spin_unlock(&rbd_dev_list_lock);
4189 dout("rbd_dev %p given dev id %llu\n", rbd_dev,
4190 (unsigned long long) rbd_dev->dev_id);
4194 * Remove an rbd_dev from the global list, and record that its
4195 * identifier is no longer in use.
4197 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4199 struct list_head *tmp;
4200 int rbd_id = rbd_dev->dev_id;
4203 rbd_assert(rbd_id > 0);
4205 dout("rbd_dev %p released dev id %llu\n", rbd_dev,
4206 (unsigned long long) rbd_dev->dev_id);
4207 spin_lock(&rbd_dev_list_lock);
4208 list_del_init(&rbd_dev->node);
4211 * If the id being "put" is not the current maximum, there
4212 * is nothing special we need to do.
4214 if (rbd_id != atomic64_read(&rbd_dev_id_max)) {
4215 spin_unlock(&rbd_dev_list_lock);
4220 * We need to update the current maximum id. Search the
4221 * list to find out what it is. We're more likely to find
4222 * the maximum at the end, so search the list backward.
4225 list_for_each_prev(tmp, &rbd_dev_list) {
4226 struct rbd_device *rbd_dev;
4228 rbd_dev = list_entry(tmp, struct rbd_device, node);
4229 if (rbd_dev->dev_id > max_id)
4230 max_id = rbd_dev->dev_id;
4232 spin_unlock(&rbd_dev_list_lock);
4235 * The max id could have been updated by rbd_dev_id_get(), in
4236 * which case it now accurately reflects the new maximum.
4237 * Be careful not to overwrite the maximum value in that
4240 atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id);
4241 dout(" max dev id has been reset\n");
4245 * Skips over white space at *buf, and updates *buf to point to the
4246 * first found non-space character (if any). Returns the length of
4247 * the token (string of non-white space characters) found. Note
4248 * that *buf must be terminated with '\0'.
4250 static inline size_t next_token(const char **buf)
4253 * These are the characters that produce nonzero for
4254 * isspace() in the "C" and "POSIX" locales.
4256 const char *spaces = " \f\n\r\t\v";
4258 *buf += strspn(*buf, spaces); /* Find start of token */
4260 return strcspn(*buf, spaces); /* Return token length */
4264 * Finds the next token in *buf, and if the provided token buffer is
4265 * big enough, copies the found token into it. The result, if
4266 * copied, is guaranteed to be terminated with '\0'. Note that *buf
4267 * must be terminated with '\0' on entry.
4269 * Returns the length of the token found (not including the '\0').
4270 * Return value will be 0 if no token is found, and it will be >=
4271 * token_size if the token would not fit.
4273 * The *buf pointer will be updated to point beyond the end of the
4274 * found token. Note that this occurs even if the token buffer is
4275 * too small to hold it.
4277 static inline size_t copy_token(const char **buf,
4283 len = next_token(buf);
4284 if (len < token_size) {
4285 memcpy(token, *buf, len);
4286 *(token + len) = '\0';
4294 * Finds the next token in *buf, dynamically allocates a buffer big
4295 * enough to hold a copy of it, and copies the token into the new
4296 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4297 * that a duplicate buffer is created even for a zero-length token.
4299 * Returns a pointer to the newly-allocated duplicate, or a null
4300 * pointer if memory for the duplicate was not available. If
4301 * the lenp argument is a non-null pointer, the length of the token
4302 * (not including the '\0') is returned in *lenp.
4304 * If successful, the *buf pointer will be updated to point beyond
4305 * the end of the found token.
4307 * Note: uses GFP_KERNEL for allocation.
4309 static inline char *dup_token(const char **buf, size_t *lenp)
4314 len = next_token(buf);
4315 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4318 *(dup + len) = '\0';
4328 * Parse the options provided for an "rbd add" (i.e., rbd image
4329 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4330 * and the data written is passed here via a NUL-terminated buffer.
4331 * Returns 0 if successful or an error code otherwise.
4333 * The information extracted from these options is recorded in
4334 * the other parameters which return dynamically-allocated
4337 * The address of a pointer that will refer to a ceph options
4338 * structure. Caller must release the returned pointer using
4339 * ceph_destroy_options() when it is no longer needed.
4341 * Address of an rbd options pointer. Fully initialized by
4342 * this function; caller must release with kfree().
4344 * Address of an rbd image specification pointer. Fully
4345 * initialized by this function based on parsed options.
4346 * Caller must release with rbd_spec_put().
4348 * The options passed take this form:
4349 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4352 * A comma-separated list of one or more monitor addresses.
4353 * A monitor address is an ip address, optionally followed
4354 * by a port number (separated by a colon).
4355 * I.e.: ip1[:port1][,ip2[:port2]...]
4357 * A comma-separated list of ceph and/or rbd options.
4359 * The name of the rados pool containing the rbd image.
4361 * The name of the image in that pool to map.
4363 * An optional snapshot id. If provided, the mapping will
4364 * present data from the image at the time that snapshot was
4365 * created. The image head is used if no snapshot id is
4366 * provided. Snapshot mappings are always read-only.
4368 static int rbd_add_parse_args(const char *buf,
4369 struct ceph_options **ceph_opts,
4370 struct rbd_options **opts,
4371 struct rbd_spec **rbd_spec)
4375 const char *mon_addrs;
4377 size_t mon_addrs_size;
4378 struct rbd_spec *spec = NULL;
4379 struct rbd_options *rbd_opts = NULL;
4380 struct ceph_options *copts;
4383 /* The first four tokens are required */
4385 len = next_token(&buf);
4387 rbd_warn(NULL, "no monitor address(es) provided");
4391 mon_addrs_size = len + 1;
4395 options = dup_token(&buf, NULL);
4399 rbd_warn(NULL, "no options provided");
4403 spec = rbd_spec_alloc();
4407 spec->pool_name = dup_token(&buf, NULL);
4408 if (!spec->pool_name)
4410 if (!*spec->pool_name) {
4411 rbd_warn(NULL, "no pool name provided");
4415 spec->image_name = dup_token(&buf, NULL);
4416 if (!spec->image_name)
4418 if (!*spec->image_name) {
4419 rbd_warn(NULL, "no image name provided");
4424 * Snapshot name is optional; default is to use "-"
4425 * (indicating the head/no snapshot).
4427 len = next_token(&buf);
4429 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4430 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4431 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4432 ret = -ENAMETOOLONG;
4435 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4438 *(snap_name + len) = '\0';
4439 spec->snap_name = snap_name;
4441 /* Initialize all rbd options to the defaults */
4443 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4447 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4449 copts = ceph_parse_options(options, mon_addrs,
4450 mon_addrs + mon_addrs_size - 1,
4451 parse_rbd_opts_token, rbd_opts);
4452 if (IS_ERR(copts)) {
4453 ret = PTR_ERR(copts);
4474 * An rbd format 2 image has a unique identifier, distinct from the
4475 * name given to it by the user. Internally, that identifier is
4476 * what's used to specify the names of objects related to the image.
4478 * A special "rbd id" object is used to map an rbd image name to its
4479 * id. If that object doesn't exist, then there is no v2 rbd image
4480 * with the supplied name.
4482 * This function will record the given rbd_dev's image_id field if
4483 * it can be determined, and in that case will return 0. If any
4484 * errors occur a negative errno will be returned and the rbd_dev's
4485 * image_id field will be unchanged (and should be NULL).
4487 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
4496 * When probing a parent image, the image id is already
4497 * known (and the image name likely is not). There's no
4498 * need to fetch the image id again in this case. We
4499 * do still need to set the image format though.
4501 if (rbd_dev->spec->image_id) {
4502 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
4508 * First, see if the format 2 image id file exists, and if
4509 * so, get the image's persistent id from it.
4511 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
4512 object_name = kmalloc(size, GFP_NOIO);
4515 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
4516 dout("rbd id object name is %s\n", object_name);
4518 /* Response will be an encoded string, which includes a length */
4520 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
4521 response = kzalloc(size, GFP_NOIO);
4527 /* If it doesn't exist we'll assume it's a format 1 image */
4529 ret = rbd_obj_method_sync(rbd_dev, object_name,
4530 "rbd", "get_id", NULL, 0,
4531 response, RBD_IMAGE_ID_LEN_MAX);
4532 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4533 if (ret == -ENOENT) {
4534 image_id = kstrdup("", GFP_KERNEL);
4535 ret = image_id ? 0 : -ENOMEM;
4537 rbd_dev->image_format = 1;
4538 } else if (ret > sizeof (__le32)) {
4541 image_id = ceph_extract_encoded_string(&p, p + ret,
4543 ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
4545 rbd_dev->image_format = 2;
4551 rbd_dev->spec->image_id = image_id;
4552 dout("image_id is %s\n", image_id);
4561 /* Undo whatever state changes are made by v1 or v2 image probe */
4563 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
4565 struct rbd_image_header *header;
4567 rbd_dev_remove_parent(rbd_dev);
4568 rbd_spec_put(rbd_dev->parent_spec);
4569 rbd_dev->parent_spec = NULL;
4570 rbd_dev->parent_overlap = 0;
4572 /* Free dynamic fields from the header, then zero it out */
4574 header = &rbd_dev->header;
4575 ceph_put_snap_context(header->snapc);
4576 kfree(header->snap_sizes);
4577 kfree(header->snap_names);
4578 kfree(header->object_prefix);
4579 memset(header, 0, sizeof (*header));
4582 static int rbd_dev_v1_probe(struct rbd_device *rbd_dev)
4586 /* Populate rbd image metadata */
4588 ret = rbd_read_header(rbd_dev, &rbd_dev->header);
4592 /* Version 1 images have no parent (no layering) */
4594 rbd_dev->parent_spec = NULL;
4595 rbd_dev->parent_overlap = 0;
4597 dout("discovered version 1 image, header name is %s\n",
4598 rbd_dev->header_name);
4603 kfree(rbd_dev->header_name);
4604 rbd_dev->header_name = NULL;
4605 kfree(rbd_dev->spec->image_id);
4606 rbd_dev->spec->image_id = NULL;
4611 static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
4615 ret = rbd_dev_v2_image_size(rbd_dev);
4619 /* Get the object prefix (a.k.a. block_name) for the image */
4621 ret = rbd_dev_v2_object_prefix(rbd_dev);
4625 /* Get the and check features for the image */
4627 ret = rbd_dev_v2_features(rbd_dev);
4631 /* If the image supports layering, get the parent info */
4633 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
4634 ret = rbd_dev_v2_parent_info(rbd_dev);
4639 * Don't print a warning for parent images. We can
4640 * tell this point because we won't know its pool
4641 * name yet (just its pool id).
4643 if (rbd_dev->spec->pool_name)
4644 rbd_warn(rbd_dev, "WARNING: kernel layering "
4645 "is EXPERIMENTAL!");
4648 /* If the image supports fancy striping, get its parameters */
4650 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
4651 ret = rbd_dev_v2_striping_info(rbd_dev);
4656 /* crypto and compression type aren't (yet) supported for v2 images */
4658 rbd_dev->header.crypt_type = 0;
4659 rbd_dev->header.comp_type = 0;
4661 /* Get the snapshot context, plus the header version */
4663 ret = rbd_dev_v2_snap_context(rbd_dev);
4667 dout("discovered version 2 image, header name is %s\n",
4668 rbd_dev->header_name);
4672 rbd_dev->parent_overlap = 0;
4673 rbd_spec_put(rbd_dev->parent_spec);
4674 rbd_dev->parent_spec = NULL;
4675 kfree(rbd_dev->header_name);
4676 rbd_dev->header_name = NULL;
4677 kfree(rbd_dev->header.object_prefix);
4678 rbd_dev->header.object_prefix = NULL;
4683 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
4685 struct rbd_device *parent = NULL;
4686 struct rbd_spec *parent_spec;
4687 struct rbd_client *rbdc;
4690 if (!rbd_dev->parent_spec)
4693 * We need to pass a reference to the client and the parent
4694 * spec when creating the parent rbd_dev. Images related by
4695 * parent/child relationships always share both.
4697 parent_spec = rbd_spec_get(rbd_dev->parent_spec);
4698 rbdc = __rbd_get_client(rbd_dev->rbd_client);
4701 parent = rbd_dev_create(rbdc, parent_spec);
4705 ret = rbd_dev_image_probe(parent);
4708 rbd_dev->parent = parent;
4713 rbd_spec_put(rbd_dev->parent_spec);
4714 kfree(rbd_dev->header_name);
4715 rbd_dev_destroy(parent);
4717 rbd_put_client(rbdc);
4718 rbd_spec_put(parent_spec);
4724 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
4728 ret = rbd_dev_mapping_set(rbd_dev);
4732 /* generate unique id: find highest unique id, add one */
4733 rbd_dev_id_get(rbd_dev);
4735 /* Fill in the device name, now that we have its id. */
4736 BUILD_BUG_ON(DEV_NAME_LEN
4737 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
4738 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
4740 /* Get our block major device number. */
4742 ret = register_blkdev(0, rbd_dev->name);
4745 rbd_dev->major = ret;
4747 /* Set up the blkdev mapping. */
4749 ret = rbd_init_disk(rbd_dev);
4751 goto err_out_blkdev;
4753 ret = rbd_bus_add_dev(rbd_dev);
4757 /* Everything's ready. Announce the disk to the world. */
4759 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
4760 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4761 add_disk(rbd_dev->disk);
4763 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
4764 (unsigned long long) rbd_dev->mapping.size);
4769 rbd_free_disk(rbd_dev);
4771 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4773 rbd_dev_id_put(rbd_dev);
4774 rbd_dev_mapping_clear(rbd_dev);
4779 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
4781 struct rbd_spec *spec = rbd_dev->spec;
4784 /* Record the header object name for this rbd image. */
4786 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4788 if (rbd_dev->image_format == 1)
4789 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
4791 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
4793 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
4794 if (!rbd_dev->header_name)
4797 if (rbd_dev->image_format == 1)
4798 sprintf(rbd_dev->header_name, "%s%s",
4799 spec->image_name, RBD_SUFFIX);
4801 sprintf(rbd_dev->header_name, "%s%s",
4802 RBD_HEADER_PREFIX, spec->image_id);
4806 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
4810 rbd_remove_all_snaps(rbd_dev);
4811 rbd_dev_unprobe(rbd_dev);
4812 ret = rbd_dev_header_watch_sync(rbd_dev, 0);
4814 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
4815 kfree(rbd_dev->header_name);
4816 rbd_dev->header_name = NULL;
4817 rbd_dev->image_format = 0;
4818 kfree(rbd_dev->spec->image_id);
4819 rbd_dev->spec->image_id = NULL;
4821 rbd_dev_destroy(rbd_dev);
4825 * Probe for the existence of the header object for the given rbd
4826 * device. For format 2 images this includes determining the image
4829 static int rbd_dev_image_probe(struct rbd_device *rbd_dev)
4835 * Get the id from the image id object. If it's not a
4836 * format 2 image, we'll get ENOENT back, and we'll assume
4837 * it's a format 1 image.
4839 ret = rbd_dev_image_id(rbd_dev);
4842 rbd_assert(rbd_dev->spec->image_id);
4843 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4845 ret = rbd_dev_header_name(rbd_dev);
4847 goto err_out_format;
4849 ret = rbd_dev_header_watch_sync(rbd_dev, 1);
4851 goto out_header_name;
4853 if (rbd_dev->image_format == 1)
4854 ret = rbd_dev_v1_probe(rbd_dev);
4856 ret = rbd_dev_v2_probe(rbd_dev);
4860 ret = rbd_dev_snaps_update(rbd_dev);
4864 ret = rbd_dev_spec_update(rbd_dev);
4868 ret = rbd_dev_probe_parent(rbd_dev);
4873 rbd_remove_all_snaps(rbd_dev);
4875 rbd_dev_unprobe(rbd_dev);
4877 tmp = rbd_dev_header_watch_sync(rbd_dev, 0);
4879 rbd_warn(rbd_dev, "unable to tear down watch request\n");
4881 kfree(rbd_dev->header_name);
4882 rbd_dev->header_name = NULL;
4884 rbd_dev->image_format = 0;
4885 kfree(rbd_dev->spec->image_id);
4886 rbd_dev->spec->image_id = NULL;
4888 dout("probe failed, returning %d\n", ret);
4893 static ssize_t rbd_add(struct bus_type *bus,
4897 struct rbd_device *rbd_dev = NULL;
4898 struct ceph_options *ceph_opts = NULL;
4899 struct rbd_options *rbd_opts = NULL;
4900 struct rbd_spec *spec = NULL;
4901 struct rbd_client *rbdc;
4902 struct ceph_osd_client *osdc;
4905 if (!try_module_get(THIS_MODULE))
4908 /* parse add command */
4909 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
4911 goto err_out_module;
4913 rbdc = rbd_get_client(ceph_opts);
4918 ceph_opts = NULL; /* rbd_dev client now owns this */
4921 osdc = &rbdc->client->osdc;
4922 rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
4924 goto err_out_client;
4925 spec->pool_id = (u64)rc;
4927 /* The ceph file layout needs to fit pool id in 32 bits */
4929 if (spec->pool_id > (u64)U32_MAX) {
4930 rbd_warn(NULL, "pool id too large (%llu > %u)\n",
4931 (unsigned long long)spec->pool_id, U32_MAX);
4933 goto err_out_client;
4936 rbd_dev = rbd_dev_create(rbdc, spec);
4938 goto err_out_client;
4939 rbdc = NULL; /* rbd_dev now owns this */
4940 spec = NULL; /* rbd_dev now owns this */
4942 rbd_dev->mapping.read_only = rbd_opts->read_only;
4944 rbd_opts = NULL; /* done with this */
4946 rc = rbd_dev_image_probe(rbd_dev);
4948 goto err_out_rbd_dev;
4950 rc = rbd_dev_device_setup(rbd_dev);
4954 rbd_dev_image_release(rbd_dev);
4956 rbd_dev_destroy(rbd_dev);
4958 rbd_put_client(rbdc);
4961 ceph_destroy_options(ceph_opts);
4965 module_put(THIS_MODULE);
4967 dout("Error adding device %s\n", buf);
4972 static struct rbd_device *__rbd_get_dev(unsigned long dev_id)
4974 struct list_head *tmp;
4975 struct rbd_device *rbd_dev;
4977 spin_lock(&rbd_dev_list_lock);
4978 list_for_each(tmp, &rbd_dev_list) {
4979 rbd_dev = list_entry(tmp, struct rbd_device, node);
4980 if (rbd_dev->dev_id == dev_id) {
4981 spin_unlock(&rbd_dev_list_lock);
4985 spin_unlock(&rbd_dev_list_lock);
4989 static void rbd_dev_device_release(struct device *dev)
4991 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4993 rbd_free_disk(rbd_dev);
4994 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4995 rbd_dev_clear_mapping(rbd_dev);
4996 unregister_blkdev(rbd_dev->major, rbd_dev->name);
4998 rbd_dev_id_put(rbd_dev);
4999 rbd_dev_mapping_clear(rbd_dev);
5002 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
5004 while (rbd_dev->parent) {
5005 struct rbd_device *first = rbd_dev;
5006 struct rbd_device *second = first->parent;
5007 struct rbd_device *third;
5010 * Follow to the parent with no grandparent and
5013 while (second && (third = second->parent)) {
5018 rbd_dev_image_release(second);
5019 first->parent = NULL;
5020 first->parent_overlap = 0;
5022 rbd_assert(first->parent_spec);
5023 rbd_spec_put(first->parent_spec);
5024 first->parent_spec = NULL;
5028 static ssize_t rbd_remove(struct bus_type *bus,
5032 struct rbd_device *rbd_dev = NULL;
5037 ret = strict_strtoul(buf, 10, &ul);
5041 /* convert to int; abort if we lost anything in the conversion */
5042 target_id = (int) ul;
5043 if (target_id != ul)
5046 mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
5048 rbd_dev = __rbd_get_dev(target_id);
5054 spin_lock_irq(&rbd_dev->lock);
5055 if (rbd_dev->open_count)
5058 set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
5059 spin_unlock_irq(&rbd_dev->lock);
5063 rbd_bus_del_dev(rbd_dev);
5064 rbd_dev_image_release(rbd_dev);
5065 module_put(THIS_MODULE);
5067 mutex_unlock(&ctl_mutex);
5073 * create control files in sysfs
5076 static int rbd_sysfs_init(void)
5080 ret = device_register(&rbd_root_dev);
5084 ret = bus_register(&rbd_bus_type);
5086 device_unregister(&rbd_root_dev);
5091 static void rbd_sysfs_cleanup(void)
5093 bus_unregister(&rbd_bus_type);
5094 device_unregister(&rbd_root_dev);
5097 static int __init rbd_init(void)
5101 if (!libceph_compatible(NULL)) {
5102 rbd_warn(NULL, "libceph incompatibility (quitting)");
5106 rc = rbd_sysfs_init();
5109 pr_info("loaded " RBD_DRV_NAME_LONG "\n");
5113 static void __exit rbd_exit(void)
5115 rbd_sysfs_cleanup();
5118 module_init(rbd_init);
5119 module_exit(rbd_exit);
5121 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5122 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5123 MODULE_DESCRIPTION("rados block device");
5125 /* following authorship retained from original osdblk.c */
5126 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5128 MODULE_LICENSE("GPL");