rbd: don't put snap_context twice in rbd_queue_workfn()
[linux-2.6/btrfs-unstable.git] / drivers / block / rbd.c
blob81ea69fee7ca183313b8e8322833062262279187
2 /*
3 rbd.c -- Export ceph rados objects as a Linux block device
6 based on drivers/block/osdblk.c:
8 Copyright 2009 Red Hat, Inc.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; see the file COPYING. If not, write to
21 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25 For usage instructions, please refer to:
27 Documentation/ABI/testing/sysfs-bus-rbd
31 #include <linux/ceph/libceph.h>
32 #include <linux/ceph/osd_client.h>
33 #include <linux/ceph/mon_client.h>
34 #include <linux/ceph/decode.h>
35 #include <linux/parser.h>
36 #include <linux/bsearch.h>
38 #include <linux/kernel.h>
39 #include <linux/device.h>
40 #include <linux/module.h>
41 #include <linux/blk-mq.h>
42 #include <linux/fs.h>
43 #include <linux/blkdev.h>
44 #include <linux/slab.h>
45 #include <linux/idr.h>
46 #include <linux/workqueue.h>
48 #include "rbd_types.h"
50 #define RBD_DEBUG /* Activate rbd_assert() calls */
53 * The basic unit of block I/O is a sector. It is interpreted in a
54 * number of contexts in Linux (blk, bio, genhd), but the default is
55 * universally 512 bytes. These symbols are just slightly more
56 * meaningful than the bare numbers they represent.
58 #define SECTOR_SHIFT 9
59 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT)
62 * Increment the given counter and return its updated value.
63 * If the counter is already 0 it will not be incremented.
64 * If the counter is already at its maximum value returns
65 * -EINVAL without updating it.
67 static int atomic_inc_return_safe(atomic_t *v)
69 unsigned int counter;
71 counter = (unsigned int)__atomic_add_unless(v, 1, 0);
72 if (counter <= (unsigned int)INT_MAX)
73 return (int)counter;
75 atomic_dec(v);
77 return -EINVAL;
80 /* Decrement the counter. Return the resulting value, or -EINVAL */
81 static int atomic_dec_return_safe(atomic_t *v)
83 int counter;
85 counter = atomic_dec_return(v);
86 if (counter >= 0)
87 return counter;
89 atomic_inc(v);
91 return -EINVAL;
94 #define RBD_DRV_NAME "rbd"
96 #define RBD_MINORS_PER_MAJOR 256
97 #define RBD_SINGLE_MAJOR_PART_SHIFT 4
99 #define RBD_MAX_PARENT_CHAIN_LEN 16
101 #define RBD_SNAP_DEV_NAME_PREFIX "snap_"
102 #define RBD_MAX_SNAP_NAME_LEN \
103 (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
105 #define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
107 #define RBD_SNAP_HEAD_NAME "-"
109 #define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
111 /* This allows a single page to hold an image name sent by OSD */
112 #define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
113 #define RBD_IMAGE_ID_LEN_MAX 64
115 #define RBD_OBJ_PREFIX_LEN_MAX 64
117 /* Feature bits */
119 #define RBD_FEATURE_LAYERING (1<<0)
120 #define RBD_FEATURE_STRIPINGV2 (1<<1)
121 #define RBD_FEATURES_ALL \
122 (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
124 /* Features supported by this (client software) implementation. */
126 #define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
129 * An RBD device name will be "rbd#", where the "rbd" comes from
130 * RBD_DRV_NAME above, and # is a unique integer identifier.
131 * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big
132 * enough to hold all possible device names.
134 #define DEV_NAME_LEN 32
135 #define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
138 * block device image metadata (in-memory version)
140 struct rbd_image_header {
141 /* These six fields never change for a given rbd image */
142 char *object_prefix;
143 __u8 obj_order;
144 __u8 crypt_type;
145 __u8 comp_type;
146 u64 stripe_unit;
147 u64 stripe_count;
148 u64 features; /* Might be changeable someday? */
150 /* The remaining fields need to be updated occasionally */
151 u64 image_size;
152 struct ceph_snap_context *snapc;
153 char *snap_names; /* format 1 only */
154 u64 *snap_sizes; /* format 1 only */
158 * An rbd image specification.
160 * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
161 * identify an image. Each rbd_dev structure includes a pointer to
162 * an rbd_spec structure that encapsulates this identity.
164 * Each of the id's in an rbd_spec has an associated name. For a
165 * user-mapped image, the names are supplied and the id's associated
166 * with them are looked up. For a layered image, a parent image is
167 * defined by the tuple, and the names are looked up.
169 * An rbd_dev structure contains a parent_spec pointer which is
170 * non-null if the image it represents is a child in a layered
171 * image. This pointer will refer to the rbd_spec structure used
172 * by the parent rbd_dev for its own identity (i.e., the structure
173 * is shared between the parent and child).
175 * Since these structures are populated once, during the discovery
176 * phase of image construction, they are effectively immutable so
177 * we make no effort to synchronize access to them.
179 * Note that code herein does not assume the image name is known (it
180 * could be a null pointer).
182 struct rbd_spec {
183 u64 pool_id;
184 const char *pool_name;
186 const char *image_id;
187 const char *image_name;
189 u64 snap_id;
190 const char *snap_name;
192 struct kref kref;
196 * an instance of the client. multiple devices may share an rbd client.
198 struct rbd_client {
199 struct ceph_client *client;
200 struct kref kref;
201 struct list_head node;
204 struct rbd_img_request;
205 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
207 #define BAD_WHICH U32_MAX /* Good which or bad which, which? */
209 struct rbd_obj_request;
210 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
212 enum obj_request_type {
213 OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
216 enum obj_operation_type {
217 OBJ_OP_WRITE,
218 OBJ_OP_READ,
219 OBJ_OP_DISCARD,
222 enum obj_req_flags {
223 OBJ_REQ_DONE, /* completion flag: not done = 0, done = 1 */
224 OBJ_REQ_IMG_DATA, /* object usage: standalone = 0, image = 1 */
225 OBJ_REQ_KNOWN, /* EXISTS flag valid: no = 0, yes = 1 */
226 OBJ_REQ_EXISTS, /* target exists: no = 0, yes = 1 */
229 struct rbd_obj_request {
230 const char *object_name;
231 u64 offset; /* object start byte */
232 u64 length; /* bytes from offset */
233 unsigned long flags;
236 * An object request associated with an image will have its
237 * img_data flag set; a standalone object request will not.
239 * A standalone object request will have which == BAD_WHICH
240 * and a null obj_request pointer.
242 * An object request initiated in support of a layered image
243 * object (to check for its existence before a write) will
244 * have which == BAD_WHICH and a non-null obj_request pointer.
246 * Finally, an object request for rbd image data will have
247 * which != BAD_WHICH, and will have a non-null img_request
248 * pointer. The value of which will be in the range
249 * 0..(img_request->obj_request_count-1).
251 union {
252 struct rbd_obj_request *obj_request; /* STAT op */
253 struct {
254 struct rbd_img_request *img_request;
255 u64 img_offset;
256 /* links for img_request->obj_requests list */
257 struct list_head links;
260 u32 which; /* posn image request list */
262 enum obj_request_type type;
263 union {
264 struct bio *bio_list;
265 struct {
266 struct page **pages;
267 u32 page_count;
270 struct page **copyup_pages;
271 u32 copyup_page_count;
273 struct ceph_osd_request *osd_req;
275 u64 xferred; /* bytes transferred */
276 int result;
278 rbd_obj_callback_t callback;
279 struct completion completion;
281 struct kref kref;
284 enum img_req_flags {
285 IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */
286 IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
287 IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
288 IMG_REQ_DISCARD, /* discard: normal = 0, discard request = 1 */
291 struct rbd_img_request {
292 struct rbd_device *rbd_dev;
293 u64 offset; /* starting image byte offset */
294 u64 length; /* byte count from offset */
295 unsigned long flags;
296 union {
297 u64 snap_id; /* for reads */
298 struct ceph_snap_context *snapc; /* for writes */
300 union {
301 struct request *rq; /* block request */
302 struct rbd_obj_request *obj_request; /* obj req initiator */
304 struct page **copyup_pages;
305 u32 copyup_page_count;
306 spinlock_t completion_lock;/* protects next_completion */
307 u32 next_completion;
308 rbd_img_callback_t callback;
309 u64 xferred;/* aggregate bytes transferred */
310 int result; /* first nonzero obj_request result */
312 u32 obj_request_count;
313 struct list_head obj_requests; /* rbd_obj_request structs */
315 struct kref kref;
318 #define for_each_obj_request(ireq, oreq) \
319 list_for_each_entry(oreq, &(ireq)->obj_requests, links)
320 #define for_each_obj_request_from(ireq, oreq) \
321 list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
322 #define for_each_obj_request_safe(ireq, oreq, n) \
323 list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
325 struct rbd_mapping {
326 u64 size;
327 u64 features;
328 bool read_only;
332 * a single device
334 struct rbd_device {
335 int dev_id; /* blkdev unique id */
337 int major; /* blkdev assigned major */
338 int minor;
339 struct gendisk *disk; /* blkdev's gendisk and rq */
341 u32 image_format; /* Either 1 or 2 */
342 struct rbd_client *rbd_client;
344 char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
346 spinlock_t lock; /* queue, flags, open_count */
348 struct rbd_image_header header;
349 unsigned long flags; /* possibly lock protected */
350 struct rbd_spec *spec;
351 struct rbd_options *opts;
353 char *header_name;
355 struct ceph_file_layout layout;
357 struct ceph_osd_event *watch_event;
358 struct rbd_obj_request *watch_request;
360 struct rbd_spec *parent_spec;
361 u64 parent_overlap;
362 atomic_t parent_ref;
363 struct rbd_device *parent;
365 /* Block layer tags. */
366 struct blk_mq_tag_set tag_set;
368 /* protects updating the header */
369 struct rw_semaphore header_rwsem;
371 struct rbd_mapping mapping;
373 struct list_head node;
375 /* sysfs related */
376 struct device dev;
377 unsigned long open_count; /* protected by lock */
381 * Flag bits for rbd_dev->flags. If atomicity is required,
382 * rbd_dev->lock is used to protect access.
384 * Currently, only the "removing" flag (which is coupled with the
385 * "open_count" field) requires atomic access.
387 enum rbd_dev_flags {
388 RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */
389 RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
392 static DEFINE_MUTEX(client_mutex); /* Serialize client creation */
394 static LIST_HEAD(rbd_dev_list); /* devices */
395 static DEFINE_SPINLOCK(rbd_dev_list_lock);
397 static LIST_HEAD(rbd_client_list); /* clients */
398 static DEFINE_SPINLOCK(rbd_client_list_lock);
400 /* Slab caches for frequently-allocated structures */
402 static struct kmem_cache *rbd_img_request_cache;
403 static struct kmem_cache *rbd_obj_request_cache;
404 static struct kmem_cache *rbd_segment_name_cache;
406 static int rbd_major;
407 static DEFINE_IDA(rbd_dev_id_ida);
409 static struct workqueue_struct *rbd_wq;
412 * Default to false for now, as single-major requires >= 0.75 version of
413 * userspace rbd utility.
415 static bool single_major = false;
416 module_param(single_major, bool, S_IRUGO);
417 MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: false)");
419 static int rbd_img_request_submit(struct rbd_img_request *img_request);
421 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
422 size_t count);
423 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
424 size_t count);
425 static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf,
426 size_t count);
427 static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
428 size_t count);
429 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
430 static void rbd_spec_put(struct rbd_spec *spec);
432 static int rbd_dev_id_to_minor(int dev_id)
434 return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
437 static int minor_to_rbd_dev_id(int minor)
439 return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
442 static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
443 static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
444 static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
445 static BUS_ATTR(remove_single_major, S_IWUSR, NULL, rbd_remove_single_major);
447 static struct attribute *rbd_bus_attrs[] = {
448 &bus_attr_add.attr,
449 &bus_attr_remove.attr,
450 &bus_attr_add_single_major.attr,
451 &bus_attr_remove_single_major.attr,
452 NULL,
455 static umode_t rbd_bus_is_visible(struct kobject *kobj,
456 struct attribute *attr, int index)
458 if (!single_major &&
459 (attr == &bus_attr_add_single_major.attr ||
460 attr == &bus_attr_remove_single_major.attr))
461 return 0;
463 return attr->mode;
466 static const struct attribute_group rbd_bus_group = {
467 .attrs = rbd_bus_attrs,
468 .is_visible = rbd_bus_is_visible,
470 __ATTRIBUTE_GROUPS(rbd_bus);
472 static struct bus_type rbd_bus_type = {
473 .name = "rbd",
474 .bus_groups = rbd_bus_groups,
477 static void rbd_root_dev_release(struct device *dev)
481 static struct device rbd_root_dev = {
482 .init_name = "rbd",
483 .release = rbd_root_dev_release,
486 static __printf(2, 3)
487 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
489 struct va_format vaf;
490 va_list args;
492 va_start(args, fmt);
493 vaf.fmt = fmt;
494 vaf.va = &args;
496 if (!rbd_dev)
497 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
498 else if (rbd_dev->disk)
499 printk(KERN_WARNING "%s: %s: %pV\n",
500 RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
501 else if (rbd_dev->spec && rbd_dev->spec->image_name)
502 printk(KERN_WARNING "%s: image %s: %pV\n",
503 RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
504 else if (rbd_dev->spec && rbd_dev->spec->image_id)
505 printk(KERN_WARNING "%s: id %s: %pV\n",
506 RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
507 else /* punt */
508 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
509 RBD_DRV_NAME, rbd_dev, &vaf);
510 va_end(args);
513 #ifdef RBD_DEBUG
514 #define rbd_assert(expr) \
515 if (unlikely(!(expr))) { \
516 printk(KERN_ERR "\nAssertion failure in %s() " \
517 "at line %d:\n\n" \
518 "\trbd_assert(%s);\n\n", \
519 __func__, __LINE__, #expr); \
520 BUG(); \
522 #else /* !RBD_DEBUG */
523 # define rbd_assert(expr) ((void) 0)
524 #endif /* !RBD_DEBUG */
526 static void rbd_osd_copyup_callback(struct rbd_obj_request *obj_request);
527 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
528 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
529 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
531 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
532 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
533 static int rbd_dev_header_info(struct rbd_device *rbd_dev);
534 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
535 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
536 u64 snap_id);
537 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
538 u8 *order, u64 *snap_size);
539 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
540 u64 *snap_features);
541 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name);
543 static int rbd_open(struct block_device *bdev, fmode_t mode)
545 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
546 bool removing = false;
548 if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
549 return -EROFS;
551 spin_lock_irq(&rbd_dev->lock);
552 if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
553 removing = true;
554 else
555 rbd_dev->open_count++;
556 spin_unlock_irq(&rbd_dev->lock);
557 if (removing)
558 return -ENOENT;
560 (void) get_device(&rbd_dev->dev);
562 return 0;
565 static void rbd_release(struct gendisk *disk, fmode_t mode)
567 struct rbd_device *rbd_dev = disk->private_data;
568 unsigned long open_count_before;
570 spin_lock_irq(&rbd_dev->lock);
571 open_count_before = rbd_dev->open_count--;
572 spin_unlock_irq(&rbd_dev->lock);
573 rbd_assert(open_count_before > 0);
575 put_device(&rbd_dev->dev);
578 static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
580 int ret = 0;
581 int val;
582 bool ro;
583 bool ro_changed = false;
585 /* get_user() may sleep, so call it before taking rbd_dev->lock */
586 if (get_user(val, (int __user *)(arg)))
587 return -EFAULT;
589 ro = val ? true : false;
590 /* Snapshot doesn't allow to write*/
591 if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
592 return -EROFS;
594 spin_lock_irq(&rbd_dev->lock);
595 /* prevent others open this device */
596 if (rbd_dev->open_count > 1) {
597 ret = -EBUSY;
598 goto out;
601 if (rbd_dev->mapping.read_only != ro) {
602 rbd_dev->mapping.read_only = ro;
603 ro_changed = true;
606 out:
607 spin_unlock_irq(&rbd_dev->lock);
608 /* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
609 if (ret == 0 && ro_changed)
610 set_disk_ro(rbd_dev->disk, ro ? 1 : 0);
612 return ret;
615 static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
616 unsigned int cmd, unsigned long arg)
618 struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
619 int ret = 0;
621 switch (cmd) {
622 case BLKROSET:
623 ret = rbd_ioctl_set_ro(rbd_dev, arg);
624 break;
625 default:
626 ret = -ENOTTY;
629 return ret;
632 #ifdef CONFIG_COMPAT
633 static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
634 unsigned int cmd, unsigned long arg)
636 return rbd_ioctl(bdev, mode, cmd, arg);
638 #endif /* CONFIG_COMPAT */
640 static const struct block_device_operations rbd_bd_ops = {
641 .owner = THIS_MODULE,
642 .open = rbd_open,
643 .release = rbd_release,
644 .ioctl = rbd_ioctl,
645 #ifdef CONFIG_COMPAT
646 .compat_ioctl = rbd_compat_ioctl,
647 #endif
651 * Initialize an rbd client instance. Success or not, this function
652 * consumes ceph_opts. Caller holds client_mutex.
654 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
656 struct rbd_client *rbdc;
657 int ret = -ENOMEM;
659 dout("%s:\n", __func__);
660 rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
661 if (!rbdc)
662 goto out_opt;
664 kref_init(&rbdc->kref);
665 INIT_LIST_HEAD(&rbdc->node);
667 rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
668 if (IS_ERR(rbdc->client))
669 goto out_rbdc;
670 ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
672 ret = ceph_open_session(rbdc->client);
673 if (ret < 0)
674 goto out_client;
676 spin_lock(&rbd_client_list_lock);
677 list_add_tail(&rbdc->node, &rbd_client_list);
678 spin_unlock(&rbd_client_list_lock);
680 dout("%s: rbdc %p\n", __func__, rbdc);
682 return rbdc;
683 out_client:
684 ceph_destroy_client(rbdc->client);
685 out_rbdc:
686 kfree(rbdc);
687 out_opt:
688 if (ceph_opts)
689 ceph_destroy_options(ceph_opts);
690 dout("%s: error %d\n", __func__, ret);
692 return ERR_PTR(ret);
695 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
697 kref_get(&rbdc->kref);
699 return rbdc;
703 * Find a ceph client with specific addr and configuration. If
704 * found, bump its reference count.
706 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
708 struct rbd_client *client_node;
709 bool found = false;
711 if (ceph_opts->flags & CEPH_OPT_NOSHARE)
712 return NULL;
714 spin_lock(&rbd_client_list_lock);
715 list_for_each_entry(client_node, &rbd_client_list, node) {
716 if (!ceph_compare_options(ceph_opts, client_node->client)) {
717 __rbd_get_client(client_node);
719 found = true;
720 break;
723 spin_unlock(&rbd_client_list_lock);
725 return found ? client_node : NULL;
729 * (Per device) rbd map options
731 enum {
732 Opt_queue_depth,
733 Opt_last_int,
734 /* int args above */
735 Opt_last_string,
736 /* string args above */
737 Opt_read_only,
738 Opt_read_write,
739 Opt_err
742 static match_table_t rbd_opts_tokens = {
743 {Opt_queue_depth, "queue_depth=%d"},
744 /* int args above */
745 /* string args above */
746 {Opt_read_only, "read_only"},
747 {Opt_read_only, "ro"}, /* Alternate spelling */
748 {Opt_read_write, "read_write"},
749 {Opt_read_write, "rw"}, /* Alternate spelling */
750 {Opt_err, NULL}
753 struct rbd_options {
754 int queue_depth;
755 bool read_only;
758 #define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_MAX_RQ
759 #define RBD_READ_ONLY_DEFAULT false
761 static int parse_rbd_opts_token(char *c, void *private)
763 struct rbd_options *rbd_opts = private;
764 substring_t argstr[MAX_OPT_ARGS];
765 int token, intval, ret;
767 token = match_token(c, rbd_opts_tokens, argstr);
768 if (token < Opt_last_int) {
769 ret = match_int(&argstr[0], &intval);
770 if (ret < 0) {
771 pr_err("bad mount option arg (not int) at '%s'\n", c);
772 return ret;
774 dout("got int token %d val %d\n", token, intval);
775 } else if (token > Opt_last_int && token < Opt_last_string) {
776 dout("got string token %d val %s\n", token, argstr[0].from);
777 } else {
778 dout("got token %d\n", token);
781 switch (token) {
782 case Opt_queue_depth:
783 if (intval < 1) {
784 pr_err("queue_depth out of range\n");
785 return -EINVAL;
787 rbd_opts->queue_depth = intval;
788 break;
789 case Opt_read_only:
790 rbd_opts->read_only = true;
791 break;
792 case Opt_read_write:
793 rbd_opts->read_only = false;
794 break;
795 default:
796 /* libceph prints "bad option" msg */
797 return -EINVAL;
800 return 0;
803 static char* obj_op_name(enum obj_operation_type op_type)
805 switch (op_type) {
806 case OBJ_OP_READ:
807 return "read";
808 case OBJ_OP_WRITE:
809 return "write";
810 case OBJ_OP_DISCARD:
811 return "discard";
812 default:
813 return "???";
818 * Get a ceph client with specific addr and configuration, if one does
819 * not exist create it. Either way, ceph_opts is consumed by this
820 * function.
822 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
824 struct rbd_client *rbdc;
826 mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
827 rbdc = rbd_client_find(ceph_opts);
828 if (rbdc) /* using an existing client */
829 ceph_destroy_options(ceph_opts);
830 else
831 rbdc = rbd_client_create(ceph_opts);
832 mutex_unlock(&client_mutex);
834 return rbdc;
838 * Destroy ceph client
840 * Caller must hold rbd_client_list_lock.
842 static void rbd_client_release(struct kref *kref)
844 struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
846 dout("%s: rbdc %p\n", __func__, rbdc);
847 spin_lock(&rbd_client_list_lock);
848 list_del(&rbdc->node);
849 spin_unlock(&rbd_client_list_lock);
851 ceph_destroy_client(rbdc->client);
852 kfree(rbdc);
856 * Drop reference to ceph client node. If it's not referenced anymore, release
857 * it.
859 static void rbd_put_client(struct rbd_client *rbdc)
861 if (rbdc)
862 kref_put(&rbdc->kref, rbd_client_release);
865 static bool rbd_image_format_valid(u32 image_format)
867 return image_format == 1 || image_format == 2;
870 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
872 size_t size;
873 u32 snap_count;
875 /* The header has to start with the magic rbd header text */
876 if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
877 return false;
879 /* The bio layer requires at least sector-sized I/O */
881 if (ondisk->options.order < SECTOR_SHIFT)
882 return false;
884 /* If we use u64 in a few spots we may be able to loosen this */
886 if (ondisk->options.order > 8 * sizeof (int) - 1)
887 return false;
890 * The size of a snapshot header has to fit in a size_t, and
891 * that limits the number of snapshots.
893 snap_count = le32_to_cpu(ondisk->snap_count);
894 size = SIZE_MAX - sizeof (struct ceph_snap_context);
895 if (snap_count > size / sizeof (__le64))
896 return false;
899 * Not only that, but the size of the entire the snapshot
900 * header must also be representable in a size_t.
902 size -= snap_count * sizeof (__le64);
903 if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
904 return false;
906 return true;
910 * Fill an rbd image header with information from the given format 1
911 * on-disk header.
913 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
914 struct rbd_image_header_ondisk *ondisk)
916 struct rbd_image_header *header = &rbd_dev->header;
917 bool first_time = header->object_prefix == NULL;
918 struct ceph_snap_context *snapc;
919 char *object_prefix = NULL;
920 char *snap_names = NULL;
921 u64 *snap_sizes = NULL;
922 u32 snap_count;
923 size_t size;
924 int ret = -ENOMEM;
925 u32 i;
927 /* Allocate this now to avoid having to handle failure below */
929 if (first_time) {
930 size_t len;
932 len = strnlen(ondisk->object_prefix,
933 sizeof (ondisk->object_prefix));
934 object_prefix = kmalloc(len + 1, GFP_KERNEL);
935 if (!object_prefix)
936 return -ENOMEM;
937 memcpy(object_prefix, ondisk->object_prefix, len);
938 object_prefix[len] = '\0';
941 /* Allocate the snapshot context and fill it in */
943 snap_count = le32_to_cpu(ondisk->snap_count);
944 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
945 if (!snapc)
946 goto out_err;
947 snapc->seq = le64_to_cpu(ondisk->snap_seq);
948 if (snap_count) {
949 struct rbd_image_snap_ondisk *snaps;
950 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
952 /* We'll keep a copy of the snapshot names... */
954 if (snap_names_len > (u64)SIZE_MAX)
955 goto out_2big;
956 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
957 if (!snap_names)
958 goto out_err;
960 /* ...as well as the array of their sizes. */
962 size = snap_count * sizeof (*header->snap_sizes);
963 snap_sizes = kmalloc(size, GFP_KERNEL);
964 if (!snap_sizes)
965 goto out_err;
968 * Copy the names, and fill in each snapshot's id
969 * and size.
971 * Note that rbd_dev_v1_header_info() guarantees the
972 * ondisk buffer we're working with has
973 * snap_names_len bytes beyond the end of the
974 * snapshot id array, this memcpy() is safe.
976 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
977 snaps = ondisk->snaps;
978 for (i = 0; i < snap_count; i++) {
979 snapc->snaps[i] = le64_to_cpu(snaps[i].id);
980 snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
984 /* We won't fail any more, fill in the header */
986 if (first_time) {
987 header->object_prefix = object_prefix;
988 header->obj_order = ondisk->options.order;
989 header->crypt_type = ondisk->options.crypt_type;
990 header->comp_type = ondisk->options.comp_type;
991 /* The rest aren't used for format 1 images */
992 header->stripe_unit = 0;
993 header->stripe_count = 0;
994 header->features = 0;
995 } else {
996 ceph_put_snap_context(header->snapc);
997 kfree(header->snap_names);
998 kfree(header->snap_sizes);
1001 /* The remaining fields always get updated (when we refresh) */
1003 header->image_size = le64_to_cpu(ondisk->image_size);
1004 header->snapc = snapc;
1005 header->snap_names = snap_names;
1006 header->snap_sizes = snap_sizes;
1008 return 0;
1009 out_2big:
1010 ret = -EIO;
1011 out_err:
1012 kfree(snap_sizes);
1013 kfree(snap_names);
1014 ceph_put_snap_context(snapc);
1015 kfree(object_prefix);
1017 return ret;
1020 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
1022 const char *snap_name;
1024 rbd_assert(which < rbd_dev->header.snapc->num_snaps);
1026 /* Skip over names until we find the one we are looking for */
1028 snap_name = rbd_dev->header.snap_names;
1029 while (which--)
1030 snap_name += strlen(snap_name) + 1;
1032 return kstrdup(snap_name, GFP_KERNEL);
1036 * Snapshot id comparison function for use with qsort()/bsearch().
1037 * Note that result is for snapshots in *descending* order.
1039 static int snapid_compare_reverse(const void *s1, const void *s2)
1041 u64 snap_id1 = *(u64 *)s1;
1042 u64 snap_id2 = *(u64 *)s2;
1044 if (snap_id1 < snap_id2)
1045 return 1;
1046 return snap_id1 == snap_id2 ? 0 : -1;
1050 * Search a snapshot context to see if the given snapshot id is
1051 * present.
1053 * Returns the position of the snapshot id in the array if it's found,
1054 * or BAD_SNAP_INDEX otherwise.
1056 * Note: The snapshot array is in kept sorted (by the osd) in
1057 * reverse order, highest snapshot id first.
1059 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
1061 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1062 u64 *found;
1064 found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
1065 sizeof (snap_id), snapid_compare_reverse);
1067 return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1070 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
1071 u64 snap_id)
1073 u32 which;
1074 const char *snap_name;
1076 which = rbd_dev_snap_index(rbd_dev, snap_id);
1077 if (which == BAD_SNAP_INDEX)
1078 return ERR_PTR(-ENOENT);
1080 snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
1081 return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1084 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
1086 if (snap_id == CEPH_NOSNAP)
1087 return RBD_SNAP_HEAD_NAME;
1089 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1090 if (rbd_dev->image_format == 1)
1091 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
1093 return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1096 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
1097 u64 *snap_size)
1099 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1100 if (snap_id == CEPH_NOSNAP) {
1101 *snap_size = rbd_dev->header.image_size;
1102 } else if (rbd_dev->image_format == 1) {
1103 u32 which;
1105 which = rbd_dev_snap_index(rbd_dev, snap_id);
1106 if (which == BAD_SNAP_INDEX)
1107 return -ENOENT;
1109 *snap_size = rbd_dev->header.snap_sizes[which];
1110 } else {
1111 u64 size = 0;
1112 int ret;
1114 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
1115 if (ret)
1116 return ret;
1118 *snap_size = size;
1120 return 0;
1123 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
1124 u64 *snap_features)
1126 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1127 if (snap_id == CEPH_NOSNAP) {
1128 *snap_features = rbd_dev->header.features;
1129 } else if (rbd_dev->image_format == 1) {
1130 *snap_features = 0; /* No features for format 1 */
1131 } else {
1132 u64 features = 0;
1133 int ret;
1135 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
1136 if (ret)
1137 return ret;
1139 *snap_features = features;
1141 return 0;
1144 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
1146 u64 snap_id = rbd_dev->spec->snap_id;
1147 u64 size = 0;
1148 u64 features = 0;
1149 int ret;
1151 ret = rbd_snap_size(rbd_dev, snap_id, &size);
1152 if (ret)
1153 return ret;
1154 ret = rbd_snap_features(rbd_dev, snap_id, &features);
1155 if (ret)
1156 return ret;
1158 rbd_dev->mapping.size = size;
1159 rbd_dev->mapping.features = features;
1161 return 0;
1164 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
1166 rbd_dev->mapping.size = 0;
1167 rbd_dev->mapping.features = 0;
1170 static void rbd_segment_name_free(const char *name)
1172 /* The explicit cast here is needed to drop the const qualifier */
1174 kmem_cache_free(rbd_segment_name_cache, (void *)name);
1177 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1179 char *name;
1180 u64 segment;
1181 int ret;
1182 char *name_format;
1184 name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
1185 if (!name)
1186 return NULL;
1187 segment = offset >> rbd_dev->header.obj_order;
1188 name_format = "%s.%012llx";
1189 if (rbd_dev->image_format == 2)
1190 name_format = "%s.%016llx";
1191 ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
1192 rbd_dev->header.object_prefix, segment);
1193 if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
1194 pr_err("error formatting segment name for #%llu (%d)\n",
1195 segment, ret);
1196 rbd_segment_name_free(name);
1197 name = NULL;
1200 return name;
1203 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1205 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1207 return offset & (segment_size - 1);
1210 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1211 u64 offset, u64 length)
1213 u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1215 offset &= segment_size - 1;
1217 rbd_assert(length <= U64_MAX - offset);
1218 if (offset + length > segment_size)
1219 length = segment_size - offset;
1221 return length;
1225 * returns the size of an object in the image
1227 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1229 return 1 << header->obj_order;
1233 * bio helpers
1236 static void bio_chain_put(struct bio *chain)
1238 struct bio *tmp;
1240 while (chain) {
1241 tmp = chain;
1242 chain = chain->bi_next;
1243 bio_put(tmp);
1248 * zeros a bio chain, starting at specific offset
1250 static void zero_bio_chain(struct bio *chain, int start_ofs)
1252 struct bio_vec bv;
1253 struct bvec_iter iter;
1254 unsigned long flags;
1255 void *buf;
1256 int pos = 0;
1258 while (chain) {
1259 bio_for_each_segment(bv, chain, iter) {
1260 if (pos + bv.bv_len > start_ofs) {
1261 int remainder = max(start_ofs - pos, 0);
1262 buf = bvec_kmap_irq(&bv, &flags);
1263 memset(buf + remainder, 0,
1264 bv.bv_len - remainder);
1265 flush_dcache_page(bv.bv_page);
1266 bvec_kunmap_irq(buf, &flags);
1268 pos += bv.bv_len;
1271 chain = chain->bi_next;
1276 * similar to zero_bio_chain(), zeros data defined by a page array,
1277 * starting at the given byte offset from the start of the array and
1278 * continuing up to the given end offset. The pages array is
1279 * assumed to be big enough to hold all bytes up to the end.
1281 static void zero_pages(struct page **pages, u64 offset, u64 end)
1283 struct page **page = &pages[offset >> PAGE_SHIFT];
1285 rbd_assert(end > offset);
1286 rbd_assert(end - offset <= (u64)SIZE_MAX);
1287 while (offset < end) {
1288 size_t page_offset;
1289 size_t length;
1290 unsigned long flags;
1291 void *kaddr;
1293 page_offset = offset & ~PAGE_MASK;
1294 length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
1295 local_irq_save(flags);
1296 kaddr = kmap_atomic(*page);
1297 memset(kaddr + page_offset, 0, length);
1298 flush_dcache_page(*page);
1299 kunmap_atomic(kaddr);
1300 local_irq_restore(flags);
1302 offset += length;
1303 page++;
1308 * Clone a portion of a bio, starting at the given byte offset
1309 * and continuing for the number of bytes indicated.
1311 static struct bio *bio_clone_range(struct bio *bio_src,
1312 unsigned int offset,
1313 unsigned int len,
1314 gfp_t gfpmask)
1316 struct bio *bio;
1318 bio = bio_clone(bio_src, gfpmask);
1319 if (!bio)
1320 return NULL; /* ENOMEM */
1322 bio_advance(bio, offset);
1323 bio->bi_iter.bi_size = len;
1325 return bio;
1329 * Clone a portion of a bio chain, starting at the given byte offset
1330 * into the first bio in the source chain and continuing for the
1331 * number of bytes indicated. The result is another bio chain of
1332 * exactly the given length, or a null pointer on error.
1334 * The bio_src and offset parameters are both in-out. On entry they
1335 * refer to the first source bio and the offset into that bio where
1336 * the start of data to be cloned is located.
1338 * On return, bio_src is updated to refer to the bio in the source
1339 * chain that contains first un-cloned byte, and *offset will
1340 * contain the offset of that byte within that bio.
1342 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1343 unsigned int *offset,
1344 unsigned int len,
1345 gfp_t gfpmask)
1347 struct bio *bi = *bio_src;
1348 unsigned int off = *offset;
1349 struct bio *chain = NULL;
1350 struct bio **end;
1352 /* Build up a chain of clone bios up to the limit */
1354 if (!bi || off >= bi->bi_iter.bi_size || !len)
1355 return NULL; /* Nothing to clone */
1357 end = &chain;
1358 while (len) {
1359 unsigned int bi_size;
1360 struct bio *bio;
1362 if (!bi) {
1363 rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1364 goto out_err; /* EINVAL; ran out of bio's */
1366 bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
1367 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1368 if (!bio)
1369 goto out_err; /* ENOMEM */
1371 *end = bio;
1372 end = &bio->bi_next;
1374 off += bi_size;
1375 if (off == bi->bi_iter.bi_size) {
1376 bi = bi->bi_next;
1377 off = 0;
1379 len -= bi_size;
1381 *bio_src = bi;
1382 *offset = off;
1384 return chain;
1385 out_err:
1386 bio_chain_put(chain);
1388 return NULL;
1392 * The default/initial value for all object request flags is 0. For
1393 * each flag, once its value is set to 1 it is never reset to 0
1394 * again.
1396 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1398 if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1399 struct rbd_device *rbd_dev;
1401 rbd_dev = obj_request->img_request->rbd_dev;
1402 rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1403 obj_request);
1407 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1409 smp_mb();
1410 return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1413 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1415 if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1416 struct rbd_device *rbd_dev = NULL;
1418 if (obj_request_img_data_test(obj_request))
1419 rbd_dev = obj_request->img_request->rbd_dev;
1420 rbd_warn(rbd_dev, "obj_request %p already marked done",
1421 obj_request);
1425 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1427 smp_mb();
1428 return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1432 * This sets the KNOWN flag after (possibly) setting the EXISTS
1433 * flag. The latter is set based on the "exists" value provided.
1435 * Note that for our purposes once an object exists it never goes
1436 * away again. It's possible that the response from two existence
1437 * checks are separated by the creation of the target object, and
1438 * the first ("doesn't exist") response arrives *after* the second
1439 * ("does exist"). In that case we ignore the second one.
1441 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1442 bool exists)
1444 if (exists)
1445 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1446 set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1447 smp_mb();
1450 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1452 smp_mb();
1453 return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1456 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1458 smp_mb();
1459 return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1462 static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
1464 struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
1466 return obj_request->img_offset <
1467 round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
1470 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1472 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1473 atomic_read(&obj_request->kref.refcount));
1474 kref_get(&obj_request->kref);
1477 static void rbd_obj_request_destroy(struct kref *kref);
1478 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1480 rbd_assert(obj_request != NULL);
1481 dout("%s: obj %p (was %d)\n", __func__, obj_request,
1482 atomic_read(&obj_request->kref.refcount));
1483 kref_put(&obj_request->kref, rbd_obj_request_destroy);
1486 static void rbd_img_request_get(struct rbd_img_request *img_request)
1488 dout("%s: img %p (was %d)\n", __func__, img_request,
1489 atomic_read(&img_request->kref.refcount));
1490 kref_get(&img_request->kref);
1493 static bool img_request_child_test(struct rbd_img_request *img_request);
1494 static void rbd_parent_request_destroy(struct kref *kref);
1495 static void rbd_img_request_destroy(struct kref *kref);
1496 static void rbd_img_request_put(struct rbd_img_request *img_request)
1498 rbd_assert(img_request != NULL);
1499 dout("%s: img %p (was %d)\n", __func__, img_request,
1500 atomic_read(&img_request->kref.refcount));
1501 if (img_request_child_test(img_request))
1502 kref_put(&img_request->kref, rbd_parent_request_destroy);
1503 else
1504 kref_put(&img_request->kref, rbd_img_request_destroy);
1507 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1508 struct rbd_obj_request *obj_request)
1510 rbd_assert(obj_request->img_request == NULL);
1512 /* Image request now owns object's original reference */
1513 obj_request->img_request = img_request;
1514 obj_request->which = img_request->obj_request_count;
1515 rbd_assert(!obj_request_img_data_test(obj_request));
1516 obj_request_img_data_set(obj_request);
1517 rbd_assert(obj_request->which != BAD_WHICH);
1518 img_request->obj_request_count++;
1519 list_add_tail(&obj_request->links, &img_request->obj_requests);
1520 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1521 obj_request->which);
1524 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1525 struct rbd_obj_request *obj_request)
1527 rbd_assert(obj_request->which != BAD_WHICH);
1529 dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1530 obj_request->which);
1531 list_del(&obj_request->links);
1532 rbd_assert(img_request->obj_request_count > 0);
1533 img_request->obj_request_count--;
1534 rbd_assert(obj_request->which == img_request->obj_request_count);
1535 obj_request->which = BAD_WHICH;
1536 rbd_assert(obj_request_img_data_test(obj_request));
1537 rbd_assert(obj_request->img_request == img_request);
1538 obj_request->img_request = NULL;
1539 obj_request->callback = NULL;
1540 rbd_obj_request_put(obj_request);
1543 static bool obj_request_type_valid(enum obj_request_type type)
1545 switch (type) {
1546 case OBJ_REQUEST_NODATA:
1547 case OBJ_REQUEST_BIO:
1548 case OBJ_REQUEST_PAGES:
1549 return true;
1550 default:
1551 return false;
1555 static int rbd_obj_request_submit(struct ceph_osd_client *osdc,
1556 struct rbd_obj_request *obj_request)
1558 dout("%s %p\n", __func__, obj_request);
1559 return ceph_osdc_start_request(osdc, obj_request->osd_req, false);
1562 static void rbd_obj_request_end(struct rbd_obj_request *obj_request)
1564 dout("%s %p\n", __func__, obj_request);
1565 ceph_osdc_cancel_request(obj_request->osd_req);
1569 * Wait for an object request to complete. If interrupted, cancel the
1570 * underlying osd request.
1572 * @timeout: in jiffies, 0 means "wait forever"
1574 static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
1575 unsigned long timeout)
1577 long ret;
1579 dout("%s %p\n", __func__, obj_request);
1580 ret = wait_for_completion_interruptible_timeout(
1581 &obj_request->completion,
1582 ceph_timeout_jiffies(timeout));
1583 if (ret <= 0) {
1584 if (ret == 0)
1585 ret = -ETIMEDOUT;
1586 rbd_obj_request_end(obj_request);
1587 } else {
1588 ret = 0;
1591 dout("%s %p ret %d\n", __func__, obj_request, (int)ret);
1592 return ret;
1595 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1597 return __rbd_obj_request_wait(obj_request, 0);
1600 static int rbd_obj_request_wait_timeout(struct rbd_obj_request *obj_request,
1601 unsigned long timeout)
1603 return __rbd_obj_request_wait(obj_request, timeout);
1606 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1609 dout("%s: img %p\n", __func__, img_request);
1612 * If no error occurred, compute the aggregate transfer
1613 * count for the image request. We could instead use
1614 * atomic64_cmpxchg() to update it as each object request
1615 * completes; not clear which way is better off hand.
1617 if (!img_request->result) {
1618 struct rbd_obj_request *obj_request;
1619 u64 xferred = 0;
1621 for_each_obj_request(img_request, obj_request)
1622 xferred += obj_request->xferred;
1623 img_request->xferred = xferred;
1626 if (img_request->callback)
1627 img_request->callback(img_request);
1628 else
1629 rbd_img_request_put(img_request);
1633 * The default/initial value for all image request flags is 0. Each
1634 * is conditionally set to 1 at image request initialization time
1635 * and currently never change thereafter.
1637 static void img_request_write_set(struct rbd_img_request *img_request)
1639 set_bit(IMG_REQ_WRITE, &img_request->flags);
1640 smp_mb();
1643 static bool img_request_write_test(struct rbd_img_request *img_request)
1645 smp_mb();
1646 return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1650 * Set the discard flag when the img_request is an discard request
1652 static void img_request_discard_set(struct rbd_img_request *img_request)
1654 set_bit(IMG_REQ_DISCARD, &img_request->flags);
1655 smp_mb();
1658 static bool img_request_discard_test(struct rbd_img_request *img_request)
1660 smp_mb();
1661 return test_bit(IMG_REQ_DISCARD, &img_request->flags) != 0;
1664 static void img_request_child_set(struct rbd_img_request *img_request)
1666 set_bit(IMG_REQ_CHILD, &img_request->flags);
1667 smp_mb();
1670 static void img_request_child_clear(struct rbd_img_request *img_request)
1672 clear_bit(IMG_REQ_CHILD, &img_request->flags);
1673 smp_mb();
1676 static bool img_request_child_test(struct rbd_img_request *img_request)
1678 smp_mb();
1679 return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1682 static void img_request_layered_set(struct rbd_img_request *img_request)
1684 set_bit(IMG_REQ_LAYERED, &img_request->flags);
1685 smp_mb();
1688 static void img_request_layered_clear(struct rbd_img_request *img_request)
1690 clear_bit(IMG_REQ_LAYERED, &img_request->flags);
1691 smp_mb();
1694 static bool img_request_layered_test(struct rbd_img_request *img_request)
1696 smp_mb();
1697 return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1700 static enum obj_operation_type
1701 rbd_img_request_op_type(struct rbd_img_request *img_request)
1703 if (img_request_write_test(img_request))
1704 return OBJ_OP_WRITE;
1705 else if (img_request_discard_test(img_request))
1706 return OBJ_OP_DISCARD;
1707 else
1708 return OBJ_OP_READ;
1711 static void
1712 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1714 u64 xferred = obj_request->xferred;
1715 u64 length = obj_request->length;
1717 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1718 obj_request, obj_request->img_request, obj_request->result,
1719 xferred, length);
1721 * ENOENT means a hole in the image. We zero-fill the entire
1722 * length of the request. A short read also implies zero-fill
1723 * to the end of the request. An error requires the whole
1724 * length of the request to be reported finished with an error
1725 * to the block layer. In each case we update the xferred
1726 * count to indicate the whole request was satisfied.
1728 rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1729 if (obj_request->result == -ENOENT) {
1730 if (obj_request->type == OBJ_REQUEST_BIO)
1731 zero_bio_chain(obj_request->bio_list, 0);
1732 else
1733 zero_pages(obj_request->pages, 0, length);
1734 obj_request->result = 0;
1735 } else if (xferred < length && !obj_request->result) {
1736 if (obj_request->type == OBJ_REQUEST_BIO)
1737 zero_bio_chain(obj_request->bio_list, xferred);
1738 else
1739 zero_pages(obj_request->pages, xferred, length);
1741 obj_request->xferred = length;
1742 obj_request_done_set(obj_request);
1745 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1747 dout("%s: obj %p cb %p\n", __func__, obj_request,
1748 obj_request->callback);
1749 if (obj_request->callback)
1750 obj_request->callback(obj_request);
1751 else
1752 complete_all(&obj_request->completion);
1755 static void rbd_osd_trivial_callback(struct rbd_obj_request *obj_request)
1757 dout("%s: obj %p\n", __func__, obj_request);
1758 obj_request_done_set(obj_request);
1761 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1763 struct rbd_img_request *img_request = NULL;
1764 struct rbd_device *rbd_dev = NULL;
1765 bool layered = false;
1767 if (obj_request_img_data_test(obj_request)) {
1768 img_request = obj_request->img_request;
1769 layered = img_request && img_request_layered_test(img_request);
1770 rbd_dev = img_request->rbd_dev;
1773 dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1774 obj_request, img_request, obj_request->result,
1775 obj_request->xferred, obj_request->length);
1776 if (layered && obj_request->result == -ENOENT &&
1777 obj_request->img_offset < rbd_dev->parent_overlap)
1778 rbd_img_parent_read(obj_request);
1779 else if (img_request)
1780 rbd_img_obj_request_read_callback(obj_request);
1781 else
1782 obj_request_done_set(obj_request);
1785 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1787 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1788 obj_request->result, obj_request->length);
1790 * There is no such thing as a successful short write. Set
1791 * it to our originally-requested length.
1793 obj_request->xferred = obj_request->length;
1794 obj_request_done_set(obj_request);
1797 static void rbd_osd_discard_callback(struct rbd_obj_request *obj_request)
1799 dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1800 obj_request->result, obj_request->length);
1802 * There is no such thing as a successful short discard. Set
1803 * it to our originally-requested length.
1805 obj_request->xferred = obj_request->length;
1806 /* discarding a non-existent object is not a problem */
1807 if (obj_request->result == -ENOENT)
1808 obj_request->result = 0;
1809 obj_request_done_set(obj_request);
1813 * For a simple stat call there's nothing to do. We'll do more if
1814 * this is part of a write sequence for a layered image.
1816 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1818 dout("%s: obj %p\n", __func__, obj_request);
1819 obj_request_done_set(obj_request);
1822 static void rbd_osd_call_callback(struct rbd_obj_request *obj_request)
1824 dout("%s: obj %p\n", __func__, obj_request);
1826 if (obj_request_img_data_test(obj_request))
1827 rbd_osd_copyup_callback(obj_request);
1828 else
1829 obj_request_done_set(obj_request);
1832 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req,
1833 struct ceph_msg *msg)
1835 struct rbd_obj_request *obj_request = osd_req->r_priv;
1836 u16 opcode;
1838 dout("%s: osd_req %p msg %p\n", __func__, osd_req, msg);
1839 rbd_assert(osd_req == obj_request->osd_req);
1840 if (obj_request_img_data_test(obj_request)) {
1841 rbd_assert(obj_request->img_request);
1842 rbd_assert(obj_request->which != BAD_WHICH);
1843 } else {
1844 rbd_assert(obj_request->which == BAD_WHICH);
1847 if (osd_req->r_result < 0)
1848 obj_request->result = osd_req->r_result;
1850 rbd_assert(osd_req->r_num_ops <= CEPH_OSD_MAX_OP);
1853 * We support a 64-bit length, but ultimately it has to be
1854 * passed to the block layer, which just supports a 32-bit
1855 * length field.
1857 obj_request->xferred = osd_req->r_reply_op_len[0];
1858 rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1860 opcode = osd_req->r_ops[0].op;
1861 switch (opcode) {
1862 case CEPH_OSD_OP_READ:
1863 rbd_osd_read_callback(obj_request);
1864 break;
1865 case CEPH_OSD_OP_SETALLOCHINT:
1866 rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
1867 osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1868 /* fall through */
1869 case CEPH_OSD_OP_WRITE:
1870 case CEPH_OSD_OP_WRITEFULL:
1871 rbd_osd_write_callback(obj_request);
1872 break;
1873 case CEPH_OSD_OP_STAT:
1874 rbd_osd_stat_callback(obj_request);
1875 break;
1876 case CEPH_OSD_OP_DELETE:
1877 case CEPH_OSD_OP_TRUNCATE:
1878 case CEPH_OSD_OP_ZERO:
1879 rbd_osd_discard_callback(obj_request);
1880 break;
1881 case CEPH_OSD_OP_CALL:
1882 rbd_osd_call_callback(obj_request);
1883 break;
1884 case CEPH_OSD_OP_NOTIFY_ACK:
1885 case CEPH_OSD_OP_WATCH:
1886 rbd_osd_trivial_callback(obj_request);
1887 break;
1888 default:
1889 rbd_warn(NULL, "%s: unsupported op %hu",
1890 obj_request->object_name, (unsigned short) opcode);
1891 break;
1894 if (obj_request_done_test(obj_request))
1895 rbd_obj_request_complete(obj_request);
1898 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1900 struct rbd_img_request *img_request = obj_request->img_request;
1901 struct ceph_osd_request *osd_req = obj_request->osd_req;
1902 u64 snap_id;
1904 rbd_assert(osd_req != NULL);
1906 snap_id = img_request ? img_request->snap_id : CEPH_NOSNAP;
1907 ceph_osdc_build_request(osd_req, obj_request->offset,
1908 NULL, snap_id, NULL);
1911 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1913 struct rbd_img_request *img_request = obj_request->img_request;
1914 struct ceph_osd_request *osd_req = obj_request->osd_req;
1915 struct ceph_snap_context *snapc;
1916 struct timespec mtime = CURRENT_TIME;
1918 rbd_assert(osd_req != NULL);
1920 snapc = img_request ? img_request->snapc : NULL;
1921 ceph_osdc_build_request(osd_req, obj_request->offset,
1922 snapc, CEPH_NOSNAP, &mtime);
1926 * Create an osd request. A read request has one osd op (read).
1927 * A write request has either one (watch) or two (hint+write) osd ops.
1928 * (All rbd data writes are prefixed with an allocation hint op, but
1929 * technically osd watch is a write request, hence this distinction.)
1931 static struct ceph_osd_request *rbd_osd_req_create(
1932 struct rbd_device *rbd_dev,
1933 enum obj_operation_type op_type,
1934 unsigned int num_ops,
1935 struct rbd_obj_request *obj_request)
1937 struct ceph_snap_context *snapc = NULL;
1938 struct ceph_osd_client *osdc;
1939 struct ceph_osd_request *osd_req;
1941 if (obj_request_img_data_test(obj_request) &&
1942 (op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1943 struct rbd_img_request *img_request = obj_request->img_request;
1944 if (op_type == OBJ_OP_WRITE) {
1945 rbd_assert(img_request_write_test(img_request));
1946 } else {
1947 rbd_assert(img_request_discard_test(img_request));
1949 snapc = img_request->snapc;
1952 rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1954 /* Allocate and initialize the request, for the num_ops ops */
1956 osdc = &rbd_dev->rbd_client->client->osdc;
1957 osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
1958 GFP_ATOMIC);
1959 if (!osd_req)
1960 return NULL; /* ENOMEM */
1962 if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
1963 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
1964 else
1965 osd_req->r_flags = CEPH_OSD_FLAG_READ;
1967 osd_req->r_callback = rbd_osd_req_callback;
1968 osd_req->r_priv = obj_request;
1970 osd_req->r_base_oloc.pool = ceph_file_layout_pg_pool(rbd_dev->layout);
1971 ceph_oid_set_name(&osd_req->r_base_oid, obj_request->object_name);
1973 return osd_req;
1977 * Create a copyup osd request based on the information in the object
1978 * request supplied. A copyup request has two or three osd ops, a
1979 * copyup method call, potentially a hint op, and a write or truncate
1980 * or zero op.
1982 static struct ceph_osd_request *
1983 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
1985 struct rbd_img_request *img_request;
1986 struct ceph_snap_context *snapc;
1987 struct rbd_device *rbd_dev;
1988 struct ceph_osd_client *osdc;
1989 struct ceph_osd_request *osd_req;
1990 int num_osd_ops = 3;
1992 rbd_assert(obj_request_img_data_test(obj_request));
1993 img_request = obj_request->img_request;
1994 rbd_assert(img_request);
1995 rbd_assert(img_request_write_test(img_request) ||
1996 img_request_discard_test(img_request));
1998 if (img_request_discard_test(img_request))
1999 num_osd_ops = 2;
2001 /* Allocate and initialize the request, for all the ops */
2003 snapc = img_request->snapc;
2004 rbd_dev = img_request->rbd_dev;
2005 osdc = &rbd_dev->rbd_client->client->osdc;
2006 osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2007 false, GFP_ATOMIC);
2008 if (!osd_req)
2009 return NULL; /* ENOMEM */
2011 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
2012 osd_req->r_callback = rbd_osd_req_callback;
2013 osd_req->r_priv = obj_request;
2015 osd_req->r_base_oloc.pool = ceph_file_layout_pg_pool(rbd_dev->layout);
2016 ceph_oid_set_name(&osd_req->r_base_oid, obj_request->object_name);
2018 return osd_req;
2022 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
2024 ceph_osdc_put_request(osd_req);
2027 /* object_name is assumed to be a non-null pointer and NUL-terminated */
2029 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
2030 u64 offset, u64 length,
2031 enum obj_request_type type)
2033 struct rbd_obj_request *obj_request;
2034 size_t size;
2035 char *name;
2037 rbd_assert(obj_request_type_valid(type));
2039 size = strlen(object_name) + 1;
2040 name = kmalloc(size, GFP_NOIO);
2041 if (!name)
2042 return NULL;
2044 obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2045 if (!obj_request) {
2046 kfree(name);
2047 return NULL;
2050 obj_request->object_name = memcpy(name, object_name, size);
2051 obj_request->offset = offset;
2052 obj_request->length = length;
2053 obj_request->flags = 0;
2054 obj_request->which = BAD_WHICH;
2055 obj_request->type = type;
2056 INIT_LIST_HEAD(&obj_request->links);
2057 init_completion(&obj_request->completion);
2058 kref_init(&obj_request->kref);
2060 dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
2061 offset, length, (int)type, obj_request);
2063 return obj_request;
2066 static void rbd_obj_request_destroy(struct kref *kref)
2068 struct rbd_obj_request *obj_request;
2070 obj_request = container_of(kref, struct rbd_obj_request, kref);
2072 dout("%s: obj %p\n", __func__, obj_request);
2074 rbd_assert(obj_request->img_request == NULL);
2075 rbd_assert(obj_request->which == BAD_WHICH);
2077 if (obj_request->osd_req)
2078 rbd_osd_req_destroy(obj_request->osd_req);
2080 rbd_assert(obj_request_type_valid(obj_request->type));
2081 switch (obj_request->type) {
2082 case OBJ_REQUEST_NODATA:
2083 break; /* Nothing to do */
2084 case OBJ_REQUEST_BIO:
2085 if (obj_request->bio_list)
2086 bio_chain_put(obj_request->bio_list);
2087 break;
2088 case OBJ_REQUEST_PAGES:
2089 if (obj_request->pages)
2090 ceph_release_page_vector(obj_request->pages,
2091 obj_request->page_count);
2092 break;
2095 kfree(obj_request->object_name);
2096 obj_request->object_name = NULL;
2097 kmem_cache_free(rbd_obj_request_cache, obj_request);
2100 /* It's OK to call this for a device with no parent */
2102 static void rbd_spec_put(struct rbd_spec *spec);
2103 static void rbd_dev_unparent(struct rbd_device *rbd_dev)
2105 rbd_dev_remove_parent(rbd_dev);
2106 rbd_spec_put(rbd_dev->parent_spec);
2107 rbd_dev->parent_spec = NULL;
2108 rbd_dev->parent_overlap = 0;
2112 * Parent image reference counting is used to determine when an
2113 * image's parent fields can be safely torn down--after there are no
2114 * more in-flight requests to the parent image. When the last
2115 * reference is dropped, cleaning them up is safe.
2117 static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
2119 int counter;
2121 if (!rbd_dev->parent_spec)
2122 return;
2124 counter = atomic_dec_return_safe(&rbd_dev->parent_ref);
2125 if (counter > 0)
2126 return;
2128 /* Last reference; clean up parent data structures */
2130 if (!counter)
2131 rbd_dev_unparent(rbd_dev);
2132 else
2133 rbd_warn(rbd_dev, "parent reference underflow");
2137 * If an image has a non-zero parent overlap, get a reference to its
2138 * parent.
2140 * Returns true if the rbd device has a parent with a non-zero
2141 * overlap and a reference for it was successfully taken, or
2142 * false otherwise.
2144 static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
2146 int counter = 0;
2148 if (!rbd_dev->parent_spec)
2149 return false;
2151 down_read(&rbd_dev->header_rwsem);
2152 if (rbd_dev->parent_overlap)
2153 counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
2154 up_read(&rbd_dev->header_rwsem);
2156 if (counter < 0)
2157 rbd_warn(rbd_dev, "parent reference overflow");
2159 return counter > 0;
2163 * Caller is responsible for filling in the list of object requests
2164 * that comprises the image request, and the Linux request pointer
2165 * (if there is one).
2167 static struct rbd_img_request *rbd_img_request_create(
2168 struct rbd_device *rbd_dev,
2169 u64 offset, u64 length,
2170 enum obj_operation_type op_type,
2171 struct ceph_snap_context *snapc)
2173 struct rbd_img_request *img_request;
2175 img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
2176 if (!img_request)
2177 return NULL;
2179 img_request->rq = NULL;
2180 img_request->rbd_dev = rbd_dev;
2181 img_request->offset = offset;
2182 img_request->length = length;
2183 img_request->flags = 0;
2184 if (op_type == OBJ_OP_DISCARD) {
2185 img_request_discard_set(img_request);
2186 img_request->snapc = snapc;
2187 } else if (op_type == OBJ_OP_WRITE) {
2188 img_request_write_set(img_request);
2189 img_request->snapc = snapc;
2190 } else {
2191 img_request->snap_id = rbd_dev->spec->snap_id;
2193 if (rbd_dev_parent_get(rbd_dev))
2194 img_request_layered_set(img_request);
2195 spin_lock_init(&img_request->completion_lock);
2196 img_request->next_completion = 0;
2197 img_request->callback = NULL;
2198 img_request->result = 0;
2199 img_request->obj_request_count = 0;
2200 INIT_LIST_HEAD(&img_request->obj_requests);
2201 kref_init(&img_request->kref);
2203 dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
2204 obj_op_name(op_type), offset, length, img_request);
2206 return img_request;
2209 static void rbd_img_request_destroy(struct kref *kref)
2211 struct rbd_img_request *img_request;
2212 struct rbd_obj_request *obj_request;
2213 struct rbd_obj_request *next_obj_request;
2215 img_request = container_of(kref, struct rbd_img_request, kref);
2217 dout("%s: img %p\n", __func__, img_request);
2219 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2220 rbd_img_obj_request_del(img_request, obj_request);
2221 rbd_assert(img_request->obj_request_count == 0);
2223 if (img_request_layered_test(img_request)) {
2224 img_request_layered_clear(img_request);
2225 rbd_dev_parent_put(img_request->rbd_dev);
2228 if (img_request_write_test(img_request) ||
2229 img_request_discard_test(img_request))
2230 ceph_put_snap_context(img_request->snapc);
2232 kmem_cache_free(rbd_img_request_cache, img_request);
2235 static struct rbd_img_request *rbd_parent_request_create(
2236 struct rbd_obj_request *obj_request,
2237 u64 img_offset, u64 length)
2239 struct rbd_img_request *parent_request;
2240 struct rbd_device *rbd_dev;
2242 rbd_assert(obj_request->img_request);
2243 rbd_dev = obj_request->img_request->rbd_dev;
2245 parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
2246 length, OBJ_OP_READ, NULL);
2247 if (!parent_request)
2248 return NULL;
2250 img_request_child_set(parent_request);
2251 rbd_obj_request_get(obj_request);
2252 parent_request->obj_request = obj_request;
2254 return parent_request;
2257 static void rbd_parent_request_destroy(struct kref *kref)
2259 struct rbd_img_request *parent_request;
2260 struct rbd_obj_request *orig_request;
2262 parent_request = container_of(kref, struct rbd_img_request, kref);
2263 orig_request = parent_request->obj_request;
2265 parent_request->obj_request = NULL;
2266 rbd_obj_request_put(orig_request);
2267 img_request_child_clear(parent_request);
2269 rbd_img_request_destroy(kref);
2272 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
2274 struct rbd_img_request *img_request;
2275 unsigned int xferred;
2276 int result;
2277 bool more;
2279 rbd_assert(obj_request_img_data_test(obj_request));
2280 img_request = obj_request->img_request;
2282 rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
2283 xferred = (unsigned int)obj_request->xferred;
2284 result = obj_request->result;
2285 if (result) {
2286 struct rbd_device *rbd_dev = img_request->rbd_dev;
2287 enum obj_operation_type op_type;
2289 if (img_request_discard_test(img_request))
2290 op_type = OBJ_OP_DISCARD;
2291 else if (img_request_write_test(img_request))
2292 op_type = OBJ_OP_WRITE;
2293 else
2294 op_type = OBJ_OP_READ;
2296 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
2297 obj_op_name(op_type), obj_request->length,
2298 obj_request->img_offset, obj_request->offset);
2299 rbd_warn(rbd_dev, " result %d xferred %x",
2300 result, xferred);
2301 if (!img_request->result)
2302 img_request->result = result;
2304 * Need to end I/O on the entire obj_request worth of
2305 * bytes in case of error.
2307 xferred = obj_request->length;
2310 /* Image object requests don't own their page array */
2312 if (obj_request->type == OBJ_REQUEST_PAGES) {
2313 obj_request->pages = NULL;
2314 obj_request->page_count = 0;
2317 if (img_request_child_test(img_request)) {
2318 rbd_assert(img_request->obj_request != NULL);
2319 more = obj_request->which < img_request->obj_request_count - 1;
2320 } else {
2321 rbd_assert(img_request->rq != NULL);
2323 more = blk_update_request(img_request->rq, result, xferred);
2324 if (!more)
2325 __blk_mq_end_request(img_request->rq, result);
2328 return more;
2331 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
2333 struct rbd_img_request *img_request;
2334 u32 which = obj_request->which;
2335 bool more = true;
2337 rbd_assert(obj_request_img_data_test(obj_request));
2338 img_request = obj_request->img_request;
2340 dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
2341 rbd_assert(img_request != NULL);
2342 rbd_assert(img_request->obj_request_count > 0);
2343 rbd_assert(which != BAD_WHICH);
2344 rbd_assert(which < img_request->obj_request_count);
2346 spin_lock_irq(&img_request->completion_lock);
2347 if (which != img_request->next_completion)
2348 goto out;
2350 for_each_obj_request_from(img_request, obj_request) {
2351 rbd_assert(more);
2352 rbd_assert(which < img_request->obj_request_count);
2354 if (!obj_request_done_test(obj_request))
2355 break;
2356 more = rbd_img_obj_end_request(obj_request);
2357 which++;
2360 rbd_assert(more ^ (which == img_request->obj_request_count));
2361 img_request->next_completion = which;
2362 out:
2363 spin_unlock_irq(&img_request->completion_lock);
2364 rbd_img_request_put(img_request);
2366 if (!more)
2367 rbd_img_request_complete(img_request);
2371 * Add individual osd ops to the given ceph_osd_request and prepare
2372 * them for submission. num_ops is the current number of
2373 * osd operations already to the object request.
2375 static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
2376 struct ceph_osd_request *osd_request,
2377 enum obj_operation_type op_type,
2378 unsigned int num_ops)
2380 struct rbd_img_request *img_request = obj_request->img_request;
2381 struct rbd_device *rbd_dev = img_request->rbd_dev;
2382 u64 object_size = rbd_obj_bytes(&rbd_dev->header);
2383 u64 offset = obj_request->offset;
2384 u64 length = obj_request->length;
2385 u64 img_end;
2386 u16 opcode;
2388 if (op_type == OBJ_OP_DISCARD) {
2389 if (!offset && length == object_size &&
2390 (!img_request_layered_test(img_request) ||
2391 !obj_request_overlaps_parent(obj_request))) {
2392 opcode = CEPH_OSD_OP_DELETE;
2393 } else if ((offset + length == object_size)) {
2394 opcode = CEPH_OSD_OP_TRUNCATE;
2395 } else {
2396 down_read(&rbd_dev->header_rwsem);
2397 img_end = rbd_dev->header.image_size;
2398 up_read(&rbd_dev->header_rwsem);
2400 if (obj_request->img_offset + length == img_end)
2401 opcode = CEPH_OSD_OP_TRUNCATE;
2402 else
2403 opcode = CEPH_OSD_OP_ZERO;
2405 } else if (op_type == OBJ_OP_WRITE) {
2406 if (!offset && length == object_size)
2407 opcode = CEPH_OSD_OP_WRITEFULL;
2408 else
2409 opcode = CEPH_OSD_OP_WRITE;
2410 osd_req_op_alloc_hint_init(osd_request, num_ops,
2411 object_size, object_size);
2412 num_ops++;
2413 } else {
2414 opcode = CEPH_OSD_OP_READ;
2417 if (opcode == CEPH_OSD_OP_DELETE)
2418 osd_req_op_init(osd_request, num_ops, opcode, 0);
2419 else
2420 osd_req_op_extent_init(osd_request, num_ops, opcode,
2421 offset, length, 0, 0);
2423 if (obj_request->type == OBJ_REQUEST_BIO)
2424 osd_req_op_extent_osd_data_bio(osd_request, num_ops,
2425 obj_request->bio_list, length);
2426 else if (obj_request->type == OBJ_REQUEST_PAGES)
2427 osd_req_op_extent_osd_data_pages(osd_request, num_ops,
2428 obj_request->pages, length,
2429 offset & ~PAGE_MASK, false, false);
2431 /* Discards are also writes */
2432 if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
2433 rbd_osd_req_format_write(obj_request);
2434 else
2435 rbd_osd_req_format_read(obj_request);
2439 * Split up an image request into one or more object requests, each
2440 * to a different object. The "type" parameter indicates whether
2441 * "data_desc" is the pointer to the head of a list of bio
2442 * structures, or the base of a page array. In either case this
2443 * function assumes data_desc describes memory sufficient to hold
2444 * all data described by the image request.
2446 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2447 enum obj_request_type type,
2448 void *data_desc)
2450 struct rbd_device *rbd_dev = img_request->rbd_dev;
2451 struct rbd_obj_request *obj_request = NULL;
2452 struct rbd_obj_request *next_obj_request;
2453 struct bio *bio_list = NULL;
2454 unsigned int bio_offset = 0;
2455 struct page **pages = NULL;
2456 enum obj_operation_type op_type;
2457 u64 img_offset;
2458 u64 resid;
2460 dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2461 (int)type, data_desc);
2463 img_offset = img_request->offset;
2464 resid = img_request->length;
2465 rbd_assert(resid > 0);
2466 op_type = rbd_img_request_op_type(img_request);
2468 if (type == OBJ_REQUEST_BIO) {
2469 bio_list = data_desc;
2470 rbd_assert(img_offset ==
2471 bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2472 } else if (type == OBJ_REQUEST_PAGES) {
2473 pages = data_desc;
2476 while (resid) {
2477 struct ceph_osd_request *osd_req;
2478 const char *object_name;
2479 u64 offset;
2480 u64 length;
2482 object_name = rbd_segment_name(rbd_dev, img_offset);
2483 if (!object_name)
2484 goto out_unwind;
2485 offset = rbd_segment_offset(rbd_dev, img_offset);
2486 length = rbd_segment_length(rbd_dev, img_offset, resid);
2487 obj_request = rbd_obj_request_create(object_name,
2488 offset, length, type);
2489 /* object request has its own copy of the object name */
2490 rbd_segment_name_free(object_name);
2491 if (!obj_request)
2492 goto out_unwind;
2495 * set obj_request->img_request before creating the
2496 * osd_request so that it gets the right snapc
2498 rbd_img_obj_request_add(img_request, obj_request);
2500 if (type == OBJ_REQUEST_BIO) {
2501 unsigned int clone_size;
2503 rbd_assert(length <= (u64)UINT_MAX);
2504 clone_size = (unsigned int)length;
2505 obj_request->bio_list =
2506 bio_chain_clone_range(&bio_list,
2507 &bio_offset,
2508 clone_size,
2509 GFP_ATOMIC);
2510 if (!obj_request->bio_list)
2511 goto out_unwind;
2512 } else if (type == OBJ_REQUEST_PAGES) {
2513 unsigned int page_count;
2515 obj_request->pages = pages;
2516 page_count = (u32)calc_pages_for(offset, length);
2517 obj_request->page_count = page_count;
2518 if ((offset + length) & ~PAGE_MASK)
2519 page_count--; /* more on last page */
2520 pages += page_count;
2523 osd_req = rbd_osd_req_create(rbd_dev, op_type,
2524 (op_type == OBJ_OP_WRITE) ? 2 : 1,
2525 obj_request);
2526 if (!osd_req)
2527 goto out_unwind;
2529 obj_request->osd_req = osd_req;
2530 obj_request->callback = rbd_img_obj_callback;
2531 obj_request->img_offset = img_offset;
2533 rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
2535 rbd_img_request_get(img_request);
2537 img_offset += length;
2538 resid -= length;
2541 return 0;
2543 out_unwind:
2544 for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2545 rbd_img_obj_request_del(img_request, obj_request);
2547 return -ENOMEM;
2550 static void
2551 rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2553 struct rbd_img_request *img_request;
2554 struct rbd_device *rbd_dev;
2555 struct page **pages;
2556 u32 page_count;
2558 dout("%s: obj %p\n", __func__, obj_request);
2560 rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
2561 obj_request->type == OBJ_REQUEST_NODATA);
2562 rbd_assert(obj_request_img_data_test(obj_request));
2563 img_request = obj_request->img_request;
2564 rbd_assert(img_request);
2566 rbd_dev = img_request->rbd_dev;
2567 rbd_assert(rbd_dev);
2569 pages = obj_request->copyup_pages;
2570 rbd_assert(pages != NULL);
2571 obj_request->copyup_pages = NULL;
2572 page_count = obj_request->copyup_page_count;
2573 rbd_assert(page_count);
2574 obj_request->copyup_page_count = 0;
2575 ceph_release_page_vector(pages, page_count);
2578 * We want the transfer count to reflect the size of the
2579 * original write request. There is no such thing as a
2580 * successful short write, so if the request was successful
2581 * we can just set it to the originally-requested length.
2583 if (!obj_request->result)
2584 obj_request->xferred = obj_request->length;
2586 obj_request_done_set(obj_request);
2589 static void
2590 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2592 struct rbd_obj_request *orig_request;
2593 struct ceph_osd_request *osd_req;
2594 struct ceph_osd_client *osdc;
2595 struct rbd_device *rbd_dev;
2596 struct page **pages;
2597 enum obj_operation_type op_type;
2598 u32 page_count;
2599 int img_result;
2600 u64 parent_length;
2602 rbd_assert(img_request_child_test(img_request));
2604 /* First get what we need from the image request */
2606 pages = img_request->copyup_pages;
2607 rbd_assert(pages != NULL);
2608 img_request->copyup_pages = NULL;
2609 page_count = img_request->copyup_page_count;
2610 rbd_assert(page_count);
2611 img_request->copyup_page_count = 0;
2613 orig_request = img_request->obj_request;
2614 rbd_assert(orig_request != NULL);
2615 rbd_assert(obj_request_type_valid(orig_request->type));
2616 img_result = img_request->result;
2617 parent_length = img_request->length;
2618 rbd_assert(parent_length == img_request->xferred);
2619 rbd_img_request_put(img_request);
2621 rbd_assert(orig_request->img_request);
2622 rbd_dev = orig_request->img_request->rbd_dev;
2623 rbd_assert(rbd_dev);
2626 * If the overlap has become 0 (most likely because the
2627 * image has been flattened) we need to free the pages
2628 * and re-submit the original write request.
2630 if (!rbd_dev->parent_overlap) {
2631 struct ceph_osd_client *osdc;
2633 ceph_release_page_vector(pages, page_count);
2634 osdc = &rbd_dev->rbd_client->client->osdc;
2635 img_result = rbd_obj_request_submit(osdc, orig_request);
2636 if (!img_result)
2637 return;
2640 if (img_result)
2641 goto out_err;
2644 * The original osd request is of no use to use any more.
2645 * We need a new one that can hold the three ops in a copyup
2646 * request. Allocate the new copyup osd request for the
2647 * original request, and release the old one.
2649 img_result = -ENOMEM;
2650 osd_req = rbd_osd_req_create_copyup(orig_request);
2651 if (!osd_req)
2652 goto out_err;
2653 rbd_osd_req_destroy(orig_request->osd_req);
2654 orig_request->osd_req = osd_req;
2655 orig_request->copyup_pages = pages;
2656 orig_request->copyup_page_count = page_count;
2658 /* Initialize the copyup op */
2660 osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2661 osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2662 false, false);
2664 /* Add the other op(s) */
2666 op_type = rbd_img_request_op_type(orig_request->img_request);
2667 rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2669 /* All set, send it off. */
2671 osdc = &rbd_dev->rbd_client->client->osdc;
2672 img_result = rbd_obj_request_submit(osdc, orig_request);
2673 if (!img_result)
2674 return;
2675 out_err:
2676 /* Record the error code and complete the request */
2678 orig_request->result = img_result;
2679 orig_request->xferred = 0;
2680 obj_request_done_set(orig_request);
2681 rbd_obj_request_complete(orig_request);
2685 * Read from the parent image the range of data that covers the
2686 * entire target of the given object request. This is used for
2687 * satisfying a layered image write request when the target of an
2688 * object request from the image request does not exist.
2690 * A page array big enough to hold the returned data is allocated
2691 * and supplied to rbd_img_request_fill() as the "data descriptor."
2692 * When the read completes, this page array will be transferred to
2693 * the original object request for the copyup operation.
2695 * If an error occurs, record it as the result of the original
2696 * object request and mark it done so it gets completed.
2698 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2700 struct rbd_img_request *img_request = NULL;
2701 struct rbd_img_request *parent_request = NULL;
2702 struct rbd_device *rbd_dev;
2703 u64 img_offset;
2704 u64 length;
2705 struct page **pages = NULL;
2706 u32 page_count;
2707 int result;
2709 rbd_assert(obj_request_img_data_test(obj_request));
2710 rbd_assert(obj_request_type_valid(obj_request->type));
2712 img_request = obj_request->img_request;
2713 rbd_assert(img_request != NULL);
2714 rbd_dev = img_request->rbd_dev;
2715 rbd_assert(rbd_dev->parent != NULL);
2718 * Determine the byte range covered by the object in the
2719 * child image to which the original request was to be sent.
2721 img_offset = obj_request->img_offset - obj_request->offset;
2722 length = (u64)1 << rbd_dev->header.obj_order;
2725 * There is no defined parent data beyond the parent
2726 * overlap, so limit what we read at that boundary if
2727 * necessary.
2729 if (img_offset + length > rbd_dev->parent_overlap) {
2730 rbd_assert(img_offset < rbd_dev->parent_overlap);
2731 length = rbd_dev->parent_overlap - img_offset;
2735 * Allocate a page array big enough to receive the data read
2736 * from the parent.
2738 page_count = (u32)calc_pages_for(0, length);
2739 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2740 if (IS_ERR(pages)) {
2741 result = PTR_ERR(pages);
2742 pages = NULL;
2743 goto out_err;
2746 result = -ENOMEM;
2747 parent_request = rbd_parent_request_create(obj_request,
2748 img_offset, length);
2749 if (!parent_request)
2750 goto out_err;
2752 result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2753 if (result)
2754 goto out_err;
2755 parent_request->copyup_pages = pages;
2756 parent_request->copyup_page_count = page_count;
2758 parent_request->callback = rbd_img_obj_parent_read_full_callback;
2759 result = rbd_img_request_submit(parent_request);
2760 if (!result)
2761 return 0;
2763 parent_request->copyup_pages = NULL;
2764 parent_request->copyup_page_count = 0;
2765 parent_request->obj_request = NULL;
2766 rbd_obj_request_put(obj_request);
2767 out_err:
2768 if (pages)
2769 ceph_release_page_vector(pages, page_count);
2770 if (parent_request)
2771 rbd_img_request_put(parent_request);
2772 obj_request->result = result;
2773 obj_request->xferred = 0;
2774 obj_request_done_set(obj_request);
2776 return result;
2779 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2781 struct rbd_obj_request *orig_request;
2782 struct rbd_device *rbd_dev;
2783 int result;
2785 rbd_assert(!obj_request_img_data_test(obj_request));
2788 * All we need from the object request is the original
2789 * request and the result of the STAT op. Grab those, then
2790 * we're done with the request.
2792 orig_request = obj_request->obj_request;
2793 obj_request->obj_request = NULL;
2794 rbd_obj_request_put(orig_request);
2795 rbd_assert(orig_request);
2796 rbd_assert(orig_request->img_request);
2798 result = obj_request->result;
2799 obj_request->result = 0;
2801 dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2802 obj_request, orig_request, result,
2803 obj_request->xferred, obj_request->length);
2804 rbd_obj_request_put(obj_request);
2807 * If the overlap has become 0 (most likely because the
2808 * image has been flattened) we need to free the pages
2809 * and re-submit the original write request.
2811 rbd_dev = orig_request->img_request->rbd_dev;
2812 if (!rbd_dev->parent_overlap) {
2813 struct ceph_osd_client *osdc;
2815 osdc = &rbd_dev->rbd_client->client->osdc;
2816 result = rbd_obj_request_submit(osdc, orig_request);
2817 if (!result)
2818 return;
2822 * Our only purpose here is to determine whether the object
2823 * exists, and we don't want to treat the non-existence as
2824 * an error. If something else comes back, transfer the
2825 * error to the original request and complete it now.
2827 if (!result) {
2828 obj_request_existence_set(orig_request, true);
2829 } else if (result == -ENOENT) {
2830 obj_request_existence_set(orig_request, false);
2831 } else if (result) {
2832 orig_request->result = result;
2833 goto out;
2837 * Resubmit the original request now that we have recorded
2838 * whether the target object exists.
2840 orig_request->result = rbd_img_obj_request_submit(orig_request);
2841 out:
2842 if (orig_request->result)
2843 rbd_obj_request_complete(orig_request);
2846 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2848 struct rbd_obj_request *stat_request;
2849 struct rbd_device *rbd_dev;
2850 struct ceph_osd_client *osdc;
2851 struct page **pages = NULL;
2852 u32 page_count;
2853 size_t size;
2854 int ret;
2857 * The response data for a STAT call consists of:
2858 * le64 length;
2859 * struct {
2860 * le32 tv_sec;
2861 * le32 tv_nsec;
2862 * } mtime;
2864 size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2865 page_count = (u32)calc_pages_for(0, size);
2866 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2867 if (IS_ERR(pages))
2868 return PTR_ERR(pages);
2870 ret = -ENOMEM;
2871 stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2872 OBJ_REQUEST_PAGES);
2873 if (!stat_request)
2874 goto out;
2876 rbd_obj_request_get(obj_request);
2877 stat_request->obj_request = obj_request;
2878 stat_request->pages = pages;
2879 stat_request->page_count = page_count;
2881 rbd_assert(obj_request->img_request);
2882 rbd_dev = obj_request->img_request->rbd_dev;
2883 stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
2884 stat_request);
2885 if (!stat_request->osd_req)
2886 goto out;
2887 stat_request->callback = rbd_img_obj_exists_callback;
2889 osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
2890 osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2891 false, false);
2892 rbd_osd_req_format_read(stat_request);
2894 osdc = &rbd_dev->rbd_client->client->osdc;
2895 ret = rbd_obj_request_submit(osdc, stat_request);
2896 out:
2897 if (ret)
2898 rbd_obj_request_put(obj_request);
2900 return ret;
2903 static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2905 struct rbd_img_request *img_request;
2906 struct rbd_device *rbd_dev;
2908 rbd_assert(obj_request_img_data_test(obj_request));
2910 img_request = obj_request->img_request;
2911 rbd_assert(img_request);
2912 rbd_dev = img_request->rbd_dev;
2914 /* Reads */
2915 if (!img_request_write_test(img_request) &&
2916 !img_request_discard_test(img_request))
2917 return true;
2919 /* Non-layered writes */
2920 if (!img_request_layered_test(img_request))
2921 return true;
2924 * Layered writes outside of the parent overlap range don't
2925 * share any data with the parent.
2927 if (!obj_request_overlaps_parent(obj_request))
2928 return true;
2931 * Entire-object layered writes - we will overwrite whatever
2932 * parent data there is anyway.
2934 if (!obj_request->offset &&
2935 obj_request->length == rbd_obj_bytes(&rbd_dev->header))
2936 return true;
2939 * If the object is known to already exist, its parent data has
2940 * already been copied.
2942 if (obj_request_known_test(obj_request) &&
2943 obj_request_exists_test(obj_request))
2944 return true;
2946 return false;
2949 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2951 if (img_obj_request_simple(obj_request)) {
2952 struct rbd_device *rbd_dev;
2953 struct ceph_osd_client *osdc;
2955 rbd_dev = obj_request->img_request->rbd_dev;
2956 osdc = &rbd_dev->rbd_client->client->osdc;
2958 return rbd_obj_request_submit(osdc, obj_request);
2962 * It's a layered write. The target object might exist but
2963 * we may not know that yet. If we know it doesn't exist,
2964 * start by reading the data for the full target object from
2965 * the parent so we can use it for a copyup to the target.
2967 if (obj_request_known_test(obj_request))
2968 return rbd_img_obj_parent_read_full(obj_request);
2970 /* We don't know whether the target exists. Go find out. */
2972 return rbd_img_obj_exists_submit(obj_request);
2975 static int rbd_img_request_submit(struct rbd_img_request *img_request)
2977 struct rbd_obj_request *obj_request;
2978 struct rbd_obj_request *next_obj_request;
2980 dout("%s: img %p\n", __func__, img_request);
2981 for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
2982 int ret;
2984 ret = rbd_img_obj_request_submit(obj_request);
2985 if (ret)
2986 return ret;
2989 return 0;
2992 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
2994 struct rbd_obj_request *obj_request;
2995 struct rbd_device *rbd_dev;
2996 u64 obj_end;
2997 u64 img_xferred;
2998 int img_result;
3000 rbd_assert(img_request_child_test(img_request));
3002 /* First get what we need from the image request and release it */
3004 obj_request = img_request->obj_request;
3005 img_xferred = img_request->xferred;
3006 img_result = img_request->result;
3007 rbd_img_request_put(img_request);
3010 * If the overlap has become 0 (most likely because the
3011 * image has been flattened) we need to re-submit the
3012 * original request.
3014 rbd_assert(obj_request);
3015 rbd_assert(obj_request->img_request);
3016 rbd_dev = obj_request->img_request->rbd_dev;
3017 if (!rbd_dev->parent_overlap) {
3018 struct ceph_osd_client *osdc;
3020 osdc = &rbd_dev->rbd_client->client->osdc;
3021 img_result = rbd_obj_request_submit(osdc, obj_request);
3022 if (!img_result)
3023 return;
3026 obj_request->result = img_result;
3027 if (obj_request->result)
3028 goto out;
3031 * We need to zero anything beyond the parent overlap
3032 * boundary. Since rbd_img_obj_request_read_callback()
3033 * will zero anything beyond the end of a short read, an
3034 * easy way to do this is to pretend the data from the
3035 * parent came up short--ending at the overlap boundary.
3037 rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
3038 obj_end = obj_request->img_offset + obj_request->length;
3039 if (obj_end > rbd_dev->parent_overlap) {
3040 u64 xferred = 0;
3042 if (obj_request->img_offset < rbd_dev->parent_overlap)
3043 xferred = rbd_dev->parent_overlap -
3044 obj_request->img_offset;
3046 obj_request->xferred = min(img_xferred, xferred);
3047 } else {
3048 obj_request->xferred = img_xferred;
3050 out:
3051 rbd_img_obj_request_read_callback(obj_request);
3052 rbd_obj_request_complete(obj_request);
3055 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
3057 struct rbd_img_request *img_request;
3058 int result;
3060 rbd_assert(obj_request_img_data_test(obj_request));
3061 rbd_assert(obj_request->img_request != NULL);
3062 rbd_assert(obj_request->result == (s32) -ENOENT);
3063 rbd_assert(obj_request_type_valid(obj_request->type));
3065 /* rbd_read_finish(obj_request, obj_request->length); */
3066 img_request = rbd_parent_request_create(obj_request,
3067 obj_request->img_offset,
3068 obj_request->length);
3069 result = -ENOMEM;
3070 if (!img_request)
3071 goto out_err;
3073 if (obj_request->type == OBJ_REQUEST_BIO)
3074 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3075 obj_request->bio_list);
3076 else
3077 result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
3078 obj_request->pages);
3079 if (result)
3080 goto out_err;
3082 img_request->callback = rbd_img_parent_read_callback;
3083 result = rbd_img_request_submit(img_request);
3084 if (result)
3085 goto out_err;
3087 return;
3088 out_err:
3089 if (img_request)
3090 rbd_img_request_put(img_request);
3091 obj_request->result = result;
3092 obj_request->xferred = 0;
3093 obj_request_done_set(obj_request);
3096 static int rbd_obj_notify_ack_sync(struct rbd_device *rbd_dev, u64 notify_id)
3098 struct rbd_obj_request *obj_request;
3099 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3100 int ret;
3102 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
3103 OBJ_REQUEST_NODATA);
3104 if (!obj_request)
3105 return -ENOMEM;
3107 ret = -ENOMEM;
3108 obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
3109 obj_request);
3110 if (!obj_request->osd_req)
3111 goto out;
3113 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
3114 notify_id, 0, 0);
3115 rbd_osd_req_format_read(obj_request);
3117 ret = rbd_obj_request_submit(osdc, obj_request);
3118 if (ret)
3119 goto out;
3120 ret = rbd_obj_request_wait(obj_request);
3121 out:
3122 rbd_obj_request_put(obj_request);
3124 return ret;
3127 static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
3129 struct rbd_device *rbd_dev = (struct rbd_device *)data;
3130 int ret;
3132 if (!rbd_dev)
3133 return;
3135 dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__,
3136 rbd_dev->header_name, (unsigned long long)notify_id,
3137 (unsigned int)opcode);
3140 * Until adequate refresh error handling is in place, there is
3141 * not much we can do here, except warn.
3143 * See http://tracker.ceph.com/issues/5040
3145 ret = rbd_dev_refresh(rbd_dev);
3146 if (ret)
3147 rbd_warn(rbd_dev, "refresh failed: %d", ret);
3149 ret = rbd_obj_notify_ack_sync(rbd_dev, notify_id);
3150 if (ret)
3151 rbd_warn(rbd_dev, "notify_ack ret %d", ret);
3155 * Send a (un)watch request and wait for the ack. Return a request
3156 * with a ref held on success or error.
3158 static struct rbd_obj_request *rbd_obj_watch_request_helper(
3159 struct rbd_device *rbd_dev,
3160 bool watch)
3162 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3163 struct ceph_options *opts = osdc->client->options;
3164 struct rbd_obj_request *obj_request;
3165 int ret;
3167 obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
3168 OBJ_REQUEST_NODATA);
3169 if (!obj_request)
3170 return ERR_PTR(-ENOMEM);
3172 obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_WRITE, 1,
3173 obj_request);
3174 if (!obj_request->osd_req) {
3175 ret = -ENOMEM;
3176 goto out;
3179 osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
3180 rbd_dev->watch_event->cookie, 0, watch);
3181 rbd_osd_req_format_write(obj_request);
3183 if (watch)
3184 ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
3186 ret = rbd_obj_request_submit(osdc, obj_request);
3187 if (ret)
3188 goto out;
3190 ret = rbd_obj_request_wait_timeout(obj_request, opts->mount_timeout);
3191 if (ret)
3192 goto out;
3194 ret = obj_request->result;
3195 if (ret) {
3196 if (watch)
3197 rbd_obj_request_end(obj_request);
3198 goto out;
3201 return obj_request;
3203 out:
3204 rbd_obj_request_put(obj_request);
3205 return ERR_PTR(ret);
3209 * Initiate a watch request, synchronously.
3211 static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev)
3213 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3214 struct rbd_obj_request *obj_request;
3215 int ret;
3217 rbd_assert(!rbd_dev->watch_event);
3218 rbd_assert(!rbd_dev->watch_request);
3220 ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
3221 &rbd_dev->watch_event);
3222 if (ret < 0)
3223 return ret;
3225 obj_request = rbd_obj_watch_request_helper(rbd_dev, true);
3226 if (IS_ERR(obj_request)) {
3227 ceph_osdc_cancel_event(rbd_dev->watch_event);
3228 rbd_dev->watch_event = NULL;
3229 return PTR_ERR(obj_request);
3233 * A watch request is set to linger, so the underlying osd
3234 * request won't go away until we unregister it. We retain
3235 * a pointer to the object request during that time (in
3236 * rbd_dev->watch_request), so we'll keep a reference to it.
3237 * We'll drop that reference after we've unregistered it in
3238 * rbd_dev_header_unwatch_sync().
3240 rbd_dev->watch_request = obj_request;
3242 return 0;
3246 * Tear down a watch request, synchronously.
3248 static void rbd_dev_header_unwatch_sync(struct rbd_device *rbd_dev)
3250 struct rbd_obj_request *obj_request;
3252 rbd_assert(rbd_dev->watch_event);
3253 rbd_assert(rbd_dev->watch_request);
3255 rbd_obj_request_end(rbd_dev->watch_request);
3256 rbd_obj_request_put(rbd_dev->watch_request);
3257 rbd_dev->watch_request = NULL;
3259 obj_request = rbd_obj_watch_request_helper(rbd_dev, false);
3260 if (!IS_ERR(obj_request))
3261 rbd_obj_request_put(obj_request);
3262 else
3263 rbd_warn(rbd_dev, "unable to tear down watch request (%ld)",
3264 PTR_ERR(obj_request));
3266 ceph_osdc_cancel_event(rbd_dev->watch_event);
3267 rbd_dev->watch_event = NULL;
3271 * Synchronous osd object method call. Returns the number of bytes
3272 * returned in the outbound buffer, or a negative error code.
3274 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3275 const char *object_name,
3276 const char *class_name,
3277 const char *method_name,
3278 const void *outbound,
3279 size_t outbound_size,
3280 void *inbound,
3281 size_t inbound_size)
3283 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3284 struct rbd_obj_request *obj_request;
3285 struct page **pages;
3286 u32 page_count;
3287 int ret;
3290 * Method calls are ultimately read operations. The result
3291 * should placed into the inbound buffer provided. They
3292 * also supply outbound data--parameters for the object
3293 * method. Currently if this is present it will be a
3294 * snapshot id.
3296 page_count = (u32)calc_pages_for(0, inbound_size);
3297 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
3298 if (IS_ERR(pages))
3299 return PTR_ERR(pages);
3301 ret = -ENOMEM;
3302 obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
3303 OBJ_REQUEST_PAGES);
3304 if (!obj_request)
3305 goto out;
3307 obj_request->pages = pages;
3308 obj_request->page_count = page_count;
3310 obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
3311 obj_request);
3312 if (!obj_request->osd_req)
3313 goto out;
3315 osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
3316 class_name, method_name);
3317 if (outbound_size) {
3318 struct ceph_pagelist *pagelist;
3320 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
3321 if (!pagelist)
3322 goto out;
3324 ceph_pagelist_init(pagelist);
3325 ceph_pagelist_append(pagelist, outbound, outbound_size);
3326 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
3327 pagelist);
3329 osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
3330 obj_request->pages, inbound_size,
3331 0, false, false);
3332 rbd_osd_req_format_read(obj_request);
3334 ret = rbd_obj_request_submit(osdc, obj_request);
3335 if (ret)
3336 goto out;
3337 ret = rbd_obj_request_wait(obj_request);
3338 if (ret)
3339 goto out;
3341 ret = obj_request->result;
3342 if (ret < 0)
3343 goto out;
3345 rbd_assert(obj_request->xferred < (u64)INT_MAX);
3346 ret = (int)obj_request->xferred;
3347 ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
3348 out:
3349 if (obj_request)
3350 rbd_obj_request_put(obj_request);
3351 else
3352 ceph_release_page_vector(pages, page_count);
3354 return ret;
3357 static void rbd_queue_workfn(struct work_struct *work)
3359 struct request *rq = blk_mq_rq_from_pdu(work);
3360 struct rbd_device *rbd_dev = rq->q->queuedata;
3361 struct rbd_img_request *img_request;
3362 struct ceph_snap_context *snapc = NULL;
3363 u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
3364 u64 length = blk_rq_bytes(rq);
3365 enum obj_operation_type op_type;
3366 u64 mapping_size;
3367 int result;
3369 if (rq->cmd_type != REQ_TYPE_FS) {
3370 dout("%s: non-fs request type %d\n", __func__,
3371 (int) rq->cmd_type);
3372 result = -EIO;
3373 goto err;
3376 if (rq->cmd_flags & REQ_DISCARD)
3377 op_type = OBJ_OP_DISCARD;
3378 else if (rq->cmd_flags & REQ_WRITE)
3379 op_type = OBJ_OP_WRITE;
3380 else
3381 op_type = OBJ_OP_READ;
3383 /* Ignore/skip any zero-length requests */
3385 if (!length) {
3386 dout("%s: zero-length request\n", __func__);
3387 result = 0;
3388 goto err_rq;
3391 /* Only reads are allowed to a read-only device */
3393 if (op_type != OBJ_OP_READ) {
3394 if (rbd_dev->mapping.read_only) {
3395 result = -EROFS;
3396 goto err_rq;
3398 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
3402 * Quit early if the mapped snapshot no longer exists. It's
3403 * still possible the snapshot will have disappeared by the
3404 * time our request arrives at the osd, but there's no sense in
3405 * sending it if we already know.
3407 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
3408 dout("request for non-existent snapshot");
3409 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
3410 result = -ENXIO;
3411 goto err_rq;
3414 if (offset && length > U64_MAX - offset + 1) {
3415 rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset,
3416 length);
3417 result = -EINVAL;
3418 goto err_rq; /* Shouldn't happen */
3421 blk_mq_start_request(rq);
3423 down_read(&rbd_dev->header_rwsem);
3424 mapping_size = rbd_dev->mapping.size;
3425 if (op_type != OBJ_OP_READ) {
3426 snapc = rbd_dev->header.snapc;
3427 ceph_get_snap_context(snapc);
3429 up_read(&rbd_dev->header_rwsem);
3431 if (offset + length > mapping_size) {
3432 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
3433 length, mapping_size);
3434 result = -EIO;
3435 goto err_rq;
3438 img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
3439 snapc);
3440 if (!img_request) {
3441 result = -ENOMEM;
3442 goto err_rq;
3444 img_request->rq = rq;
3445 snapc = NULL; /* img_request consumes a ref */
3447 if (op_type == OBJ_OP_DISCARD)
3448 result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
3449 NULL);
3450 else
3451 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3452 rq->bio);
3453 if (result)
3454 goto err_img_request;
3456 result = rbd_img_request_submit(img_request);
3457 if (result)
3458 goto err_img_request;
3460 return;
3462 err_img_request:
3463 rbd_img_request_put(img_request);
3464 err_rq:
3465 if (result)
3466 rbd_warn(rbd_dev, "%s %llx at %llx result %d",
3467 obj_op_name(op_type), length, offset, result);
3468 ceph_put_snap_context(snapc);
3469 err:
3470 blk_mq_end_request(rq, result);
3473 static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
3474 const struct blk_mq_queue_data *bd)
3476 struct request *rq = bd->rq;
3477 struct work_struct *work = blk_mq_rq_to_pdu(rq);
3479 queue_work(rbd_wq, work);
3480 return BLK_MQ_RQ_QUEUE_OK;
3483 static void rbd_free_disk(struct rbd_device *rbd_dev)
3485 struct gendisk *disk = rbd_dev->disk;
3487 if (!disk)
3488 return;
3490 rbd_dev->disk = NULL;
3491 if (disk->flags & GENHD_FL_UP) {
3492 del_gendisk(disk);
3493 if (disk->queue)
3494 blk_cleanup_queue(disk->queue);
3495 blk_mq_free_tag_set(&rbd_dev->tag_set);
3497 put_disk(disk);
3500 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
3501 const char *object_name,
3502 u64 offset, u64 length, void *buf)
3505 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3506 struct rbd_obj_request *obj_request;
3507 struct page **pages = NULL;
3508 u32 page_count;
3509 size_t size;
3510 int ret;
3512 page_count = (u32) calc_pages_for(offset, length);
3513 pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
3514 if (IS_ERR(pages))
3515 return PTR_ERR(pages);
3517 ret = -ENOMEM;
3518 obj_request = rbd_obj_request_create(object_name, offset, length,
3519 OBJ_REQUEST_PAGES);
3520 if (!obj_request)
3521 goto out;
3523 obj_request->pages = pages;
3524 obj_request->page_count = page_count;
3526 obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
3527 obj_request);
3528 if (!obj_request->osd_req)
3529 goto out;
3531 osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
3532 offset, length, 0, 0);
3533 osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
3534 obj_request->pages,
3535 obj_request->length,
3536 obj_request->offset & ~PAGE_MASK,
3537 false, false);
3538 rbd_osd_req_format_read(obj_request);
3540 ret = rbd_obj_request_submit(osdc, obj_request);
3541 if (ret)
3542 goto out;
3543 ret = rbd_obj_request_wait(obj_request);
3544 if (ret)
3545 goto out;
3547 ret = obj_request->result;
3548 if (ret < 0)
3549 goto out;
3551 rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
3552 size = (size_t) obj_request->xferred;
3553 ceph_copy_from_page_vector(pages, buf, 0, size);
3554 rbd_assert(size <= (size_t)INT_MAX);
3555 ret = (int)size;
3556 out:
3557 if (obj_request)
3558 rbd_obj_request_put(obj_request);
3559 else
3560 ceph_release_page_vector(pages, page_count);
3562 return ret;
3566 * Read the complete header for the given rbd device. On successful
3567 * return, the rbd_dev->header field will contain up-to-date
3568 * information about the image.
3570 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
3572 struct rbd_image_header_ondisk *ondisk = NULL;
3573 u32 snap_count = 0;
3574 u64 names_size = 0;
3575 u32 want_count;
3576 int ret;
3579 * The complete header will include an array of its 64-bit
3580 * snapshot ids, followed by the names of those snapshots as
3581 * a contiguous block of NUL-terminated strings. Note that
3582 * the number of snapshots could change by the time we read
3583 * it in, in which case we re-read it.
3585 do {
3586 size_t size;
3588 kfree(ondisk);
3590 size = sizeof (*ondisk);
3591 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
3592 size += names_size;
3593 ondisk = kmalloc(size, GFP_KERNEL);
3594 if (!ondisk)
3595 return -ENOMEM;
3597 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,
3598 0, size, ondisk);
3599 if (ret < 0)
3600 goto out;
3601 if ((size_t)ret < size) {
3602 ret = -ENXIO;
3603 rbd_warn(rbd_dev, "short header read (want %zd got %d)",
3604 size, ret);
3605 goto out;
3607 if (!rbd_dev_ondisk_valid(ondisk)) {
3608 ret = -ENXIO;
3609 rbd_warn(rbd_dev, "invalid header");
3610 goto out;
3613 names_size = le64_to_cpu(ondisk->snap_names_len);
3614 want_count = snap_count;
3615 snap_count = le32_to_cpu(ondisk->snap_count);
3616 } while (snap_count != want_count);
3618 ret = rbd_header_from_disk(rbd_dev, ondisk);
3619 out:
3620 kfree(ondisk);
3622 return ret;
3626 * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
3627 * has disappeared from the (just updated) snapshot context.
3629 static void rbd_exists_validate(struct rbd_device *rbd_dev)
3631 u64 snap_id;
3633 if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
3634 return;
3636 snap_id = rbd_dev->spec->snap_id;
3637 if (snap_id == CEPH_NOSNAP)
3638 return;
3640 if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
3641 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
3644 static void rbd_dev_update_size(struct rbd_device *rbd_dev)
3646 sector_t size;
3647 bool removing;
3650 * Don't hold the lock while doing disk operations,
3651 * or lock ordering will conflict with the bdev mutex via:
3652 * rbd_add() -> blkdev_get() -> rbd_open()
3654 spin_lock_irq(&rbd_dev->lock);
3655 removing = test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
3656 spin_unlock_irq(&rbd_dev->lock);
3658 * If the device is being removed, rbd_dev->disk has
3659 * been destroyed, so don't try to update its size
3661 if (!removing) {
3662 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
3663 dout("setting size to %llu sectors", (unsigned long long)size);
3664 set_capacity(rbd_dev->disk, size);
3665 revalidate_disk(rbd_dev->disk);
3669 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
3671 u64 mapping_size;
3672 int ret;
3674 down_write(&rbd_dev->header_rwsem);
3675 mapping_size = rbd_dev->mapping.size;
3677 ret = rbd_dev_header_info(rbd_dev);
3678 if (ret)
3679 goto out;
3682 * If there is a parent, see if it has disappeared due to the
3683 * mapped image getting flattened.
3685 if (rbd_dev->parent) {
3686 ret = rbd_dev_v2_parent_info(rbd_dev);
3687 if (ret)
3688 goto out;
3691 if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
3692 rbd_dev->mapping.size = rbd_dev->header.image_size;
3693 } else {
3694 /* validate mapped snapshot's EXISTS flag */
3695 rbd_exists_validate(rbd_dev);
3698 out:
3699 up_write(&rbd_dev->header_rwsem);
3700 if (!ret && mapping_size != rbd_dev->mapping.size)
3701 rbd_dev_update_size(rbd_dev);
3703 return ret;
3706 static int rbd_init_request(void *data, struct request *rq,
3707 unsigned int hctx_idx, unsigned int request_idx,
3708 unsigned int numa_node)
3710 struct work_struct *work = blk_mq_rq_to_pdu(rq);
3712 INIT_WORK(work, rbd_queue_workfn);
3713 return 0;
3716 static struct blk_mq_ops rbd_mq_ops = {
3717 .queue_rq = rbd_queue_rq,
3718 .map_queue = blk_mq_map_queue,
3719 .init_request = rbd_init_request,
3722 static int rbd_init_disk(struct rbd_device *rbd_dev)
3724 struct gendisk *disk;
3725 struct request_queue *q;
3726 u64 segment_size;
3727 int err;
3729 /* create gendisk info */
3730 disk = alloc_disk(single_major ?
3731 (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
3732 RBD_MINORS_PER_MAJOR);
3733 if (!disk)
3734 return -ENOMEM;
3736 snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
3737 rbd_dev->dev_id);
3738 disk->major = rbd_dev->major;
3739 disk->first_minor = rbd_dev->minor;
3740 if (single_major)
3741 disk->flags |= GENHD_FL_EXT_DEVT;
3742 disk->fops = &rbd_bd_ops;
3743 disk->private_data = rbd_dev;
3745 memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
3746 rbd_dev->tag_set.ops = &rbd_mq_ops;
3747 rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
3748 rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
3749 rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
3750 rbd_dev->tag_set.nr_hw_queues = 1;
3751 rbd_dev->tag_set.cmd_size = sizeof(struct work_struct);
3753 err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
3754 if (err)
3755 goto out_disk;
3757 q = blk_mq_init_queue(&rbd_dev->tag_set);
3758 if (IS_ERR(q)) {
3759 err = PTR_ERR(q);
3760 goto out_tag_set;
3763 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
3764 /* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
3766 /* set io sizes to object size */
3767 segment_size = rbd_obj_bytes(&rbd_dev->header);
3768 blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
3769 q->limits.max_sectors = queue_max_hw_sectors(q);
3770 blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
3771 blk_queue_max_segment_size(q, segment_size);
3772 blk_queue_io_min(q, segment_size);
3773 blk_queue_io_opt(q, segment_size);
3775 /* enable the discard support */
3776 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
3777 q->limits.discard_granularity = segment_size;
3778 q->limits.discard_alignment = segment_size;
3779 blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
3780 q->limits.discard_zeroes_data = 1;
3782 if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
3783 q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;
3785 disk->queue = q;
3787 q->queuedata = rbd_dev;
3789 rbd_dev->disk = disk;
3791 return 0;
3792 out_tag_set:
3793 blk_mq_free_tag_set(&rbd_dev->tag_set);
3794 out_disk:
3795 put_disk(disk);
3796 return err;
3800 sysfs
3803 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
3805 return container_of(dev, struct rbd_device, dev);
3808 static ssize_t rbd_size_show(struct device *dev,
3809 struct device_attribute *attr, char *buf)
3811 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3813 return sprintf(buf, "%llu\n",
3814 (unsigned long long)rbd_dev->mapping.size);
3818 * Note this shows the features for whatever's mapped, which is not
3819 * necessarily the base image.
3821 static ssize_t rbd_features_show(struct device *dev,
3822 struct device_attribute *attr, char *buf)
3824 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3826 return sprintf(buf, "0x%016llx\n",
3827 (unsigned long long)rbd_dev->mapping.features);
3830 static ssize_t rbd_major_show(struct device *dev,
3831 struct device_attribute *attr, char *buf)
3833 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3835 if (rbd_dev->major)
3836 return sprintf(buf, "%d\n", rbd_dev->major);
3838 return sprintf(buf, "(none)\n");
3841 static ssize_t rbd_minor_show(struct device *dev,
3842 struct device_attribute *attr, char *buf)
3844 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3846 return sprintf(buf, "%d\n", rbd_dev->minor);
3849 static ssize_t rbd_client_id_show(struct device *dev,
3850 struct device_attribute *attr, char *buf)
3852 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3854 return sprintf(buf, "client%lld\n",
3855 ceph_client_id(rbd_dev->rbd_client->client));
3858 static ssize_t rbd_pool_show(struct device *dev,
3859 struct device_attribute *attr, char *buf)
3861 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3863 return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
3866 static ssize_t rbd_pool_id_show(struct device *dev,
3867 struct device_attribute *attr, char *buf)
3869 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3871 return sprintf(buf, "%llu\n",
3872 (unsigned long long) rbd_dev->spec->pool_id);
3875 static ssize_t rbd_name_show(struct device *dev,
3876 struct device_attribute *attr, char *buf)
3878 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3880 if (rbd_dev->spec->image_name)
3881 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
3883 return sprintf(buf, "(unknown)\n");
3886 static ssize_t rbd_image_id_show(struct device *dev,
3887 struct device_attribute *attr, char *buf)
3889 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3891 return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
3895 * Shows the name of the currently-mapped snapshot (or
3896 * RBD_SNAP_HEAD_NAME for the base image).
3898 static ssize_t rbd_snap_show(struct device *dev,
3899 struct device_attribute *attr,
3900 char *buf)
3902 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3904 return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
3908 * For a v2 image, shows the chain of parent images, separated by empty
3909 * lines. For v1 images or if there is no parent, shows "(no parent
3910 * image)".
3912 static ssize_t rbd_parent_show(struct device *dev,
3913 struct device_attribute *attr,
3914 char *buf)
3916 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3917 ssize_t count = 0;
3919 if (!rbd_dev->parent)
3920 return sprintf(buf, "(no parent image)\n");
3922 for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
3923 struct rbd_spec *spec = rbd_dev->parent_spec;
3925 count += sprintf(&buf[count], "%s"
3926 "pool_id %llu\npool_name %s\n"
3927 "image_id %s\nimage_name %s\n"
3928 "snap_id %llu\nsnap_name %s\n"
3929 "overlap %llu\n",
3930 !count ? "" : "\n", /* first? */
3931 spec->pool_id, spec->pool_name,
3932 spec->image_id, spec->image_name ?: "(unknown)",
3933 spec->snap_id, spec->snap_name,
3934 rbd_dev->parent_overlap);
3937 return count;
3940 static ssize_t rbd_image_refresh(struct device *dev,
3941 struct device_attribute *attr,
3942 const char *buf,
3943 size_t size)
3945 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
3946 int ret;
3948 ret = rbd_dev_refresh(rbd_dev);
3949 if (ret)
3950 return ret;
3952 return size;
3955 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
3956 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
3957 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
3958 static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
3959 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
3960 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
3961 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
3962 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
3963 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
3964 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
3965 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
3966 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
3968 static struct attribute *rbd_attrs[] = {
3969 &dev_attr_size.attr,
3970 &dev_attr_features.attr,
3971 &dev_attr_major.attr,
3972 &dev_attr_minor.attr,
3973 &dev_attr_client_id.attr,
3974 &dev_attr_pool.attr,
3975 &dev_attr_pool_id.attr,
3976 &dev_attr_name.attr,
3977 &dev_attr_image_id.attr,
3978 &dev_attr_current_snap.attr,
3979 &dev_attr_parent.attr,
3980 &dev_attr_refresh.attr,
3981 NULL
3984 static struct attribute_group rbd_attr_group = {
3985 .attrs = rbd_attrs,
3988 static const struct attribute_group *rbd_attr_groups[] = {
3989 &rbd_attr_group,
3990 NULL
3993 static void rbd_dev_release(struct device *dev);
3995 static struct device_type rbd_device_type = {
3996 .name = "rbd",
3997 .groups = rbd_attr_groups,
3998 .release = rbd_dev_release,
4001 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
4003 kref_get(&spec->kref);
4005 return spec;
4008 static void rbd_spec_free(struct kref *kref);
4009 static void rbd_spec_put(struct rbd_spec *spec)
4011 if (spec)
4012 kref_put(&spec->kref, rbd_spec_free);
4015 static struct rbd_spec *rbd_spec_alloc(void)
4017 struct rbd_spec *spec;
4019 spec = kzalloc(sizeof (*spec), GFP_KERNEL);
4020 if (!spec)
4021 return NULL;
4023 spec->pool_id = CEPH_NOPOOL;
4024 spec->snap_id = CEPH_NOSNAP;
4025 kref_init(&spec->kref);
4027 return spec;
4030 static void rbd_spec_free(struct kref *kref)
4032 struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
4034 kfree(spec->pool_name);
4035 kfree(spec->image_id);
4036 kfree(spec->image_name);
4037 kfree(spec->snap_name);
4038 kfree(spec);
4041 static void rbd_dev_release(struct device *dev)
4043 struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4044 bool need_put = !!rbd_dev->opts;
4046 rbd_put_client(rbd_dev->rbd_client);
4047 rbd_spec_put(rbd_dev->spec);
4048 kfree(rbd_dev->opts);
4049 kfree(rbd_dev);
4052 * This is racy, but way better than putting module outside of
4053 * the release callback. The race window is pretty small, so
4054 * doing something similar to dm (dm-builtin.c) is overkill.
4056 if (need_put)
4057 module_put(THIS_MODULE);
4060 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
4061 struct rbd_spec *spec,
4062 struct rbd_options *opts)
4064 struct rbd_device *rbd_dev;
4066 rbd_dev = kzalloc(sizeof (*rbd_dev), GFP_KERNEL);
4067 if (!rbd_dev)
4068 return NULL;
4070 spin_lock_init(&rbd_dev->lock);
4071 rbd_dev->flags = 0;
4072 atomic_set(&rbd_dev->parent_ref, 0);
4073 INIT_LIST_HEAD(&rbd_dev->node);
4074 init_rwsem(&rbd_dev->header_rwsem);
4076 rbd_dev->dev.bus = &rbd_bus_type;
4077 rbd_dev->dev.type = &rbd_device_type;
4078 rbd_dev->dev.parent = &rbd_root_dev;
4079 device_initialize(&rbd_dev->dev);
4081 rbd_dev->rbd_client = rbdc;
4082 rbd_dev->spec = spec;
4083 rbd_dev->opts = opts;
4085 /* Initialize the layout used for all rbd requests */
4087 rbd_dev->layout.fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
4088 rbd_dev->layout.fl_stripe_count = cpu_to_le32(1);
4089 rbd_dev->layout.fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
4090 rbd_dev->layout.fl_pg_pool = cpu_to_le32((u32) spec->pool_id);
4093 * If this is a mapping rbd_dev (as opposed to a parent one),
4094 * pin our module. We have a ref from do_rbd_add(), so use
4095 * __module_get().
4097 if (rbd_dev->opts)
4098 __module_get(THIS_MODULE);
4100 return rbd_dev;
4103 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
4105 if (rbd_dev)
4106 put_device(&rbd_dev->dev);
4110 * Get the size and object order for an image snapshot, or if
4111 * snap_id is CEPH_NOSNAP, gets this information for the base
4112 * image.
4114 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
4115 u8 *order, u64 *snap_size)
4117 __le64 snapid = cpu_to_le64(snap_id);
4118 int ret;
4119 struct {
4120 u8 order;
4121 __le64 size;
4122 } __attribute__ ((packed)) size_buf = { 0 };
4124 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4125 "rbd", "get_size",
4126 &snapid, sizeof (snapid),
4127 &size_buf, sizeof (size_buf));
4128 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4129 if (ret < 0)
4130 return ret;
4131 if (ret < sizeof (size_buf))
4132 return -ERANGE;
4134 if (order) {
4135 *order = size_buf.order;
4136 dout(" order %u", (unsigned int)*order);
4138 *snap_size = le64_to_cpu(size_buf.size);
4140 dout(" snap_id 0x%016llx snap_size = %llu\n",
4141 (unsigned long long)snap_id,
4142 (unsigned long long)*snap_size);
4144 return 0;
4147 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
4149 return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
4150 &rbd_dev->header.obj_order,
4151 &rbd_dev->header.image_size);
4154 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
4156 void *reply_buf;
4157 int ret;
4158 void *p;
4160 reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
4161 if (!reply_buf)
4162 return -ENOMEM;
4164 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4165 "rbd", "get_object_prefix", NULL, 0,
4166 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
4167 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4168 if (ret < 0)
4169 goto out;
4171 p = reply_buf;
4172 rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
4173 p + ret, NULL, GFP_NOIO);
4174 ret = 0;
4176 if (IS_ERR(rbd_dev->header.object_prefix)) {
4177 ret = PTR_ERR(rbd_dev->header.object_prefix);
4178 rbd_dev->header.object_prefix = NULL;
4179 } else {
4180 dout(" object_prefix = %s\n", rbd_dev->header.object_prefix);
4182 out:
4183 kfree(reply_buf);
4185 return ret;
4188 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
4189 u64 *snap_features)
4191 __le64 snapid = cpu_to_le64(snap_id);
4192 struct {
4193 __le64 features;
4194 __le64 incompat;
4195 } __attribute__ ((packed)) features_buf = { 0 };
4196 u64 incompat;
4197 int ret;
4199 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4200 "rbd", "get_features",
4201 &snapid, sizeof (snapid),
4202 &features_buf, sizeof (features_buf));
4203 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4204 if (ret < 0)
4205 return ret;
4206 if (ret < sizeof (features_buf))
4207 return -ERANGE;
4209 incompat = le64_to_cpu(features_buf.incompat);
4210 if (incompat & ~RBD_FEATURES_SUPPORTED)
4211 return -ENXIO;
4213 *snap_features = le64_to_cpu(features_buf.features);
4215 dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
4216 (unsigned long long)snap_id,
4217 (unsigned long long)*snap_features,
4218 (unsigned long long)le64_to_cpu(features_buf.incompat));
4220 return 0;
4223 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
4225 return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
4226 &rbd_dev->header.features);
4229 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
4231 struct rbd_spec *parent_spec;
4232 size_t size;
4233 void *reply_buf = NULL;
4234 __le64 snapid;
4235 void *p;
4236 void *end;
4237 u64 pool_id;
4238 char *image_id;
4239 u64 snap_id;
4240 u64 overlap;
4241 int ret;
4243 parent_spec = rbd_spec_alloc();
4244 if (!parent_spec)
4245 return -ENOMEM;
4247 size = sizeof (__le64) + /* pool_id */
4248 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX + /* image_id */
4249 sizeof (__le64) + /* snap_id */
4250 sizeof (__le64); /* overlap */
4251 reply_buf = kmalloc(size, GFP_KERNEL);
4252 if (!reply_buf) {
4253 ret = -ENOMEM;
4254 goto out_err;
4257 snapid = cpu_to_le64(rbd_dev->spec->snap_id);
4258 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4259 "rbd", "get_parent",
4260 &snapid, sizeof (snapid),
4261 reply_buf, size);
4262 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4263 if (ret < 0)
4264 goto out_err;
4266 p = reply_buf;
4267 end = reply_buf + ret;
4268 ret = -ERANGE;
4269 ceph_decode_64_safe(&p, end, pool_id, out_err);
4270 if (pool_id == CEPH_NOPOOL) {
4272 * Either the parent never existed, or we have
4273 * record of it but the image got flattened so it no
4274 * longer has a parent. When the parent of a
4275 * layered image disappears we immediately set the
4276 * overlap to 0. The effect of this is that all new
4277 * requests will be treated as if the image had no
4278 * parent.
4280 if (rbd_dev->parent_overlap) {
4281 rbd_dev->parent_overlap = 0;
4282 rbd_dev_parent_put(rbd_dev);
4283 pr_info("%s: clone image has been flattened\n",
4284 rbd_dev->disk->disk_name);
4287 goto out; /* No parent? No problem. */
4290 /* The ceph file layout needs to fit pool id in 32 bits */
4292 ret = -EIO;
4293 if (pool_id > (u64)U32_MAX) {
4294 rbd_warn(NULL, "parent pool id too large (%llu > %u)",
4295 (unsigned long long)pool_id, U32_MAX);
4296 goto out_err;
4299 image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4300 if (IS_ERR(image_id)) {
4301 ret = PTR_ERR(image_id);
4302 goto out_err;
4304 ceph_decode_64_safe(&p, end, snap_id, out_err);
4305 ceph_decode_64_safe(&p, end, overlap, out_err);
4308 * The parent won't change (except when the clone is
4309 * flattened, already handled that). So we only need to
4310 * record the parent spec we have not already done so.
4312 if (!rbd_dev->parent_spec) {
4313 parent_spec->pool_id = pool_id;
4314 parent_spec->image_id = image_id;
4315 parent_spec->snap_id = snap_id;
4316 rbd_dev->parent_spec = parent_spec;
4317 parent_spec = NULL; /* rbd_dev now owns this */
4318 } else {
4319 kfree(image_id);
4323 * We always update the parent overlap. If it's zero we issue
4324 * a warning, as we will proceed as if there was no parent.
4326 if (!overlap) {
4327 if (parent_spec) {
4328 /* refresh, careful to warn just once */
4329 if (rbd_dev->parent_overlap)
4330 rbd_warn(rbd_dev,
4331 "clone now standalone (overlap became 0)");
4332 } else {
4333 /* initial probe */
4334 rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
4337 rbd_dev->parent_overlap = overlap;
4339 out:
4340 ret = 0;
4341 out_err:
4342 kfree(reply_buf);
4343 rbd_spec_put(parent_spec);
4345 return ret;
4348 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
4350 struct {
4351 __le64 stripe_unit;
4352 __le64 stripe_count;
4353 } __attribute__ ((packed)) striping_info_buf = { 0 };
4354 size_t size = sizeof (striping_info_buf);
4355 void *p;
4356 u64 obj_size;
4357 u64 stripe_unit;
4358 u64 stripe_count;
4359 int ret;
4361 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4362 "rbd", "get_stripe_unit_count", NULL, 0,
4363 (char *)&striping_info_buf, size);
4364 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4365 if (ret < 0)
4366 return ret;
4367 if (ret < size)
4368 return -ERANGE;
4371 * We don't actually support the "fancy striping" feature
4372 * (STRIPINGV2) yet, but if the striping sizes are the
4373 * defaults the behavior is the same as before. So find
4374 * out, and only fail if the image has non-default values.
4376 ret = -EINVAL;
4377 obj_size = (u64)1 << rbd_dev->header.obj_order;
4378 p = &striping_info_buf;
4379 stripe_unit = ceph_decode_64(&p);
4380 if (stripe_unit != obj_size) {
4381 rbd_warn(rbd_dev, "unsupported stripe unit "
4382 "(got %llu want %llu)",
4383 stripe_unit, obj_size);
4384 return -EINVAL;
4386 stripe_count = ceph_decode_64(&p);
4387 if (stripe_count != 1) {
4388 rbd_warn(rbd_dev, "unsupported stripe count "
4389 "(got %llu want 1)", stripe_count);
4390 return -EINVAL;
4392 rbd_dev->header.stripe_unit = stripe_unit;
4393 rbd_dev->header.stripe_count = stripe_count;
4395 return 0;
4398 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
4400 size_t image_id_size;
4401 char *image_id;
4402 void *p;
4403 void *end;
4404 size_t size;
4405 void *reply_buf = NULL;
4406 size_t len = 0;
4407 char *image_name = NULL;
4408 int ret;
4410 rbd_assert(!rbd_dev->spec->image_name);
4412 len = strlen(rbd_dev->spec->image_id);
4413 image_id_size = sizeof (__le32) + len;
4414 image_id = kmalloc(image_id_size, GFP_KERNEL);
4415 if (!image_id)
4416 return NULL;
4418 p = image_id;
4419 end = image_id + image_id_size;
4420 ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
4422 size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
4423 reply_buf = kmalloc(size, GFP_KERNEL);
4424 if (!reply_buf)
4425 goto out;
4427 ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
4428 "rbd", "dir_get_name",
4429 image_id, image_id_size,
4430 reply_buf, size);
4431 if (ret < 0)
4432 goto out;
4433 p = reply_buf;
4434 end = reply_buf + ret;
4436 image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
4437 if (IS_ERR(image_name))
4438 image_name = NULL;
4439 else
4440 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
4441 out:
4442 kfree(reply_buf);
4443 kfree(image_id);
4445 return image_name;
4448 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
4450 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
4451 const char *snap_name;
4452 u32 which = 0;
4454 /* Skip over names until we find the one we are looking for */
4456 snap_name = rbd_dev->header.snap_names;
4457 while (which < snapc->num_snaps) {
4458 if (!strcmp(name, snap_name))
4459 return snapc->snaps[which];
4460 snap_name += strlen(snap_name) + 1;
4461 which++;
4463 return CEPH_NOSNAP;
4466 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
4468 struct ceph_snap_context *snapc = rbd_dev->header.snapc;
4469 u32 which;
4470 bool found = false;
4471 u64 snap_id;
4473 for (which = 0; !found && which < snapc->num_snaps; which++) {
4474 const char *snap_name;
4476 snap_id = snapc->snaps[which];
4477 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
4478 if (IS_ERR(snap_name)) {
4479 /* ignore no-longer existing snapshots */
4480 if (PTR_ERR(snap_name) == -ENOENT)
4481 continue;
4482 else
4483 break;
4485 found = !strcmp(name, snap_name);
4486 kfree(snap_name);
4488 return found ? snap_id : CEPH_NOSNAP;
4492 * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
4493 * no snapshot by that name is found, or if an error occurs.
4495 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
4497 if (rbd_dev->image_format == 1)
4498 return rbd_v1_snap_id_by_name(rbd_dev, name);
4500 return rbd_v2_snap_id_by_name(rbd_dev, name);
4504 * An image being mapped will have everything but the snap id.
4506 static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
4508 struct rbd_spec *spec = rbd_dev->spec;
4510 rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
4511 rbd_assert(spec->image_id && spec->image_name);
4512 rbd_assert(spec->snap_name);
4514 if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
4515 u64 snap_id;
4517 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
4518 if (snap_id == CEPH_NOSNAP)
4519 return -ENOENT;
4521 spec->snap_id = snap_id;
4522 } else {
4523 spec->snap_id = CEPH_NOSNAP;
4526 return 0;
4530 * A parent image will have all ids but none of the names.
4532 * All names in an rbd spec are dynamically allocated. It's OK if we
4533 * can't figure out the name for an image id.
4535 static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
4537 struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4538 struct rbd_spec *spec = rbd_dev->spec;
4539 const char *pool_name;
4540 const char *image_name;
4541 const char *snap_name;
4542 int ret;
4544 rbd_assert(spec->pool_id != CEPH_NOPOOL);
4545 rbd_assert(spec->image_id);
4546 rbd_assert(spec->snap_id != CEPH_NOSNAP);
4548 /* Get the pool name; we have to make our own copy of this */
4550 pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
4551 if (!pool_name) {
4552 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
4553 return -EIO;
4555 pool_name = kstrdup(pool_name, GFP_KERNEL);
4556 if (!pool_name)
4557 return -ENOMEM;
4559 /* Fetch the image name; tolerate failure here */
4561 image_name = rbd_dev_image_name(rbd_dev);
4562 if (!image_name)
4563 rbd_warn(rbd_dev, "unable to get image name");
4565 /* Fetch the snapshot name */
4567 snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
4568 if (IS_ERR(snap_name)) {
4569 ret = PTR_ERR(snap_name);
4570 goto out_err;
4573 spec->pool_name = pool_name;
4574 spec->image_name = image_name;
4575 spec->snap_name = snap_name;
4577 return 0;
4579 out_err:
4580 kfree(image_name);
4581 kfree(pool_name);
4582 return ret;
4585 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
4587 size_t size;
4588 int ret;
4589 void *reply_buf;
4590 void *p;
4591 void *end;
4592 u64 seq;
4593 u32 snap_count;
4594 struct ceph_snap_context *snapc;
4595 u32 i;
4598 * We'll need room for the seq value (maximum snapshot id),
4599 * snapshot count, and array of that many snapshot ids.
4600 * For now we have a fixed upper limit on the number we're
4601 * prepared to receive.
4603 size = sizeof (__le64) + sizeof (__le32) +
4604 RBD_MAX_SNAP_COUNT * sizeof (__le64);
4605 reply_buf = kzalloc(size, GFP_KERNEL);
4606 if (!reply_buf)
4607 return -ENOMEM;
4609 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4610 "rbd", "get_snapcontext", NULL, 0,
4611 reply_buf, size);
4612 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4613 if (ret < 0)
4614 goto out;
4616 p = reply_buf;
4617 end = reply_buf + ret;
4618 ret = -ERANGE;
4619 ceph_decode_64_safe(&p, end, seq, out);
4620 ceph_decode_32_safe(&p, end, snap_count, out);
4623 * Make sure the reported number of snapshot ids wouldn't go
4624 * beyond the end of our buffer. But before checking that,
4625 * make sure the computed size of the snapshot context we
4626 * allocate is representable in a size_t.
4628 if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
4629 / sizeof (u64)) {
4630 ret = -EINVAL;
4631 goto out;
4633 if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
4634 goto out;
4635 ret = 0;
4637 snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
4638 if (!snapc) {
4639 ret = -ENOMEM;
4640 goto out;
4642 snapc->seq = seq;
4643 for (i = 0; i < snap_count; i++)
4644 snapc->snaps[i] = ceph_decode_64(&p);
4646 ceph_put_snap_context(rbd_dev->header.snapc);
4647 rbd_dev->header.snapc = snapc;
4649 dout(" snap context seq = %llu, snap_count = %u\n",
4650 (unsigned long long)seq, (unsigned int)snap_count);
4651 out:
4652 kfree(reply_buf);
4654 return ret;
4657 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
4658 u64 snap_id)
4660 size_t size;
4661 void *reply_buf;
4662 __le64 snapid;
4663 int ret;
4664 void *p;
4665 void *end;
4666 char *snap_name;
4668 size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
4669 reply_buf = kmalloc(size, GFP_KERNEL);
4670 if (!reply_buf)
4671 return ERR_PTR(-ENOMEM);
4673 snapid = cpu_to_le64(snap_id);
4674 ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
4675 "rbd", "get_snapshot_name",
4676 &snapid, sizeof (snapid),
4677 reply_buf, size);
4678 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4679 if (ret < 0) {
4680 snap_name = ERR_PTR(ret);
4681 goto out;
4684 p = reply_buf;
4685 end = reply_buf + ret;
4686 snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
4687 if (IS_ERR(snap_name))
4688 goto out;
4690 dout(" snap_id 0x%016llx snap_name = %s\n",
4691 (unsigned long long)snap_id, snap_name);
4692 out:
4693 kfree(reply_buf);
4695 return snap_name;
4698 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
4700 bool first_time = rbd_dev->header.object_prefix == NULL;
4701 int ret;
4703 ret = rbd_dev_v2_image_size(rbd_dev);
4704 if (ret)
4705 return ret;
4707 if (first_time) {
4708 ret = rbd_dev_v2_header_onetime(rbd_dev);
4709 if (ret)
4710 return ret;
4713 ret = rbd_dev_v2_snap_context(rbd_dev);
4714 if (ret && first_time) {
4715 kfree(rbd_dev->header.object_prefix);
4716 rbd_dev->header.object_prefix = NULL;
4719 return ret;
4722 static int rbd_dev_header_info(struct rbd_device *rbd_dev)
4724 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
4726 if (rbd_dev->image_format == 1)
4727 return rbd_dev_v1_header_info(rbd_dev);
4729 return rbd_dev_v2_header_info(rbd_dev);
4733 * Get a unique rbd identifier for the given new rbd_dev, and add
4734 * the rbd_dev to the global list.
4736 static int rbd_dev_id_get(struct rbd_device *rbd_dev)
4738 int new_dev_id;
4740 new_dev_id = ida_simple_get(&rbd_dev_id_ida,
4741 0, minor_to_rbd_dev_id(1 << MINORBITS),
4742 GFP_KERNEL);
4743 if (new_dev_id < 0)
4744 return new_dev_id;
4746 rbd_dev->dev_id = new_dev_id;
4748 spin_lock(&rbd_dev_list_lock);
4749 list_add_tail(&rbd_dev->node, &rbd_dev_list);
4750 spin_unlock(&rbd_dev_list_lock);
4752 dout("rbd_dev %p given dev id %d\n", rbd_dev, rbd_dev->dev_id);
4754 return 0;
4758 * Remove an rbd_dev from the global list, and record that its
4759 * identifier is no longer in use.
4761 static void rbd_dev_id_put(struct rbd_device *rbd_dev)
4763 spin_lock(&rbd_dev_list_lock);
4764 list_del_init(&rbd_dev->node);
4765 spin_unlock(&rbd_dev_list_lock);
4767 ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
4769 dout("rbd_dev %p released dev id %d\n", rbd_dev, rbd_dev->dev_id);
4773 * Skips over white space at *buf, and updates *buf to point to the
4774 * first found non-space character (if any). Returns the length of
4775 * the token (string of non-white space characters) found. Note
4776 * that *buf must be terminated with '\0'.
4778 static inline size_t next_token(const char **buf)
4781 * These are the characters that produce nonzero for
4782 * isspace() in the "C" and "POSIX" locales.
4784 const char *spaces = " \f\n\r\t\v";
4786 *buf += strspn(*buf, spaces); /* Find start of token */
4788 return strcspn(*buf, spaces); /* Return token length */
4792 * Finds the next token in *buf, dynamically allocates a buffer big
4793 * enough to hold a copy of it, and copies the token into the new
4794 * buffer. The copy is guaranteed to be terminated with '\0'. Note
4795 * that a duplicate buffer is created even for a zero-length token.
4797 * Returns a pointer to the newly-allocated duplicate, or a null
4798 * pointer if memory for the duplicate was not available. If
4799 * the lenp argument is a non-null pointer, the length of the token
4800 * (not including the '\0') is returned in *lenp.
4802 * If successful, the *buf pointer will be updated to point beyond
4803 * the end of the found token.
4805 * Note: uses GFP_KERNEL for allocation.
4807 static inline char *dup_token(const char **buf, size_t *lenp)
4809 char *dup;
4810 size_t len;
4812 len = next_token(buf);
4813 dup = kmemdup(*buf, len + 1, GFP_KERNEL);
4814 if (!dup)
4815 return NULL;
4816 *(dup + len) = '\0';
4817 *buf += len;
4819 if (lenp)
4820 *lenp = len;
4822 return dup;
4826 * Parse the options provided for an "rbd add" (i.e., rbd image
4827 * mapping) request. These arrive via a write to /sys/bus/rbd/add,
4828 * and the data written is passed here via a NUL-terminated buffer.
4829 * Returns 0 if successful or an error code otherwise.
4831 * The information extracted from these options is recorded in
4832 * the other parameters which return dynamically-allocated
4833 * structures:
4834 * ceph_opts
4835 * The address of a pointer that will refer to a ceph options
4836 * structure. Caller must release the returned pointer using
4837 * ceph_destroy_options() when it is no longer needed.
4838 * rbd_opts
4839 * Address of an rbd options pointer. Fully initialized by
4840 * this function; caller must release with kfree().
4841 * spec
4842 * Address of an rbd image specification pointer. Fully
4843 * initialized by this function based on parsed options.
4844 * Caller must release with rbd_spec_put().
4846 * The options passed take this form:
4847 * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
4848 * where:
4849 * <mon_addrs>
4850 * A comma-separated list of one or more monitor addresses.
4851 * A monitor address is an ip address, optionally followed
4852 * by a port number (separated by a colon).
4853 * I.e.: ip1[:port1][,ip2[:port2]...]
4854 * <options>
4855 * A comma-separated list of ceph and/or rbd options.
4856 * <pool_name>
4857 * The name of the rados pool containing the rbd image.
4858 * <image_name>
4859 * The name of the image in that pool to map.
4860 * <snap_id>
4861 * An optional snapshot id. If provided, the mapping will
4862 * present data from the image at the time that snapshot was
4863 * created. The image head is used if no snapshot id is
4864 * provided. Snapshot mappings are always read-only.
4866 static int rbd_add_parse_args(const char *buf,
4867 struct ceph_options **ceph_opts,
4868 struct rbd_options **opts,
4869 struct rbd_spec **rbd_spec)
4871 size_t len;
4872 char *options;
4873 const char *mon_addrs;
4874 char *snap_name;
4875 size_t mon_addrs_size;
4876 struct rbd_spec *spec = NULL;
4877 struct rbd_options *rbd_opts = NULL;
4878 struct ceph_options *copts;
4879 int ret;
4881 /* The first four tokens are required */
4883 len = next_token(&buf);
4884 if (!len) {
4885 rbd_warn(NULL, "no monitor address(es) provided");
4886 return -EINVAL;
4888 mon_addrs = buf;
4889 mon_addrs_size = len + 1;
4890 buf += len;
4892 ret = -EINVAL;
4893 options = dup_token(&buf, NULL);
4894 if (!options)
4895 return -ENOMEM;
4896 if (!*options) {
4897 rbd_warn(NULL, "no options provided");
4898 goto out_err;
4901 spec = rbd_spec_alloc();
4902 if (!spec)
4903 goto out_mem;
4905 spec->pool_name = dup_token(&buf, NULL);
4906 if (!spec->pool_name)
4907 goto out_mem;
4908 if (!*spec->pool_name) {
4909 rbd_warn(NULL, "no pool name provided");
4910 goto out_err;
4913 spec->image_name = dup_token(&buf, NULL);
4914 if (!spec->image_name)
4915 goto out_mem;
4916 if (!*spec->image_name) {
4917 rbd_warn(NULL, "no image name provided");
4918 goto out_err;
4922 * Snapshot name is optional; default is to use "-"
4923 * (indicating the head/no snapshot).
4925 len = next_token(&buf);
4926 if (!len) {
4927 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
4928 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
4929 } else if (len > RBD_MAX_SNAP_NAME_LEN) {
4930 ret = -ENAMETOOLONG;
4931 goto out_err;
4933 snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
4934 if (!snap_name)
4935 goto out_mem;
4936 *(snap_name + len) = '\0';
4937 spec->snap_name = snap_name;
4939 /* Initialize all rbd options to the defaults */
4941 rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
4942 if (!rbd_opts)
4943 goto out_mem;
4945 rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
4946 rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
4948 copts = ceph_parse_options(options, mon_addrs,
4949 mon_addrs + mon_addrs_size - 1,
4950 parse_rbd_opts_token, rbd_opts);
4951 if (IS_ERR(copts)) {
4952 ret = PTR_ERR(copts);
4953 goto out_err;
4955 kfree(options);
4957 *ceph_opts = copts;
4958 *opts = rbd_opts;
4959 *rbd_spec = spec;
4961 return 0;
4962 out_mem:
4963 ret = -ENOMEM;
4964 out_err:
4965 kfree(rbd_opts);
4966 rbd_spec_put(spec);
4967 kfree(options);
4969 return ret;
4973 * Return pool id (>= 0) or a negative error code.
4975 static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
4977 struct ceph_options *opts = rbdc->client->options;
4978 u64 newest_epoch;
4979 int tries = 0;
4980 int ret;
4982 again:
4983 ret = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, pool_name);
4984 if (ret == -ENOENT && tries++ < 1) {
4985 ret = ceph_monc_do_get_version(&rbdc->client->monc, "osdmap",
4986 &newest_epoch);
4987 if (ret < 0)
4988 return ret;
4990 if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
4991 ceph_monc_request_next_osdmap(&rbdc->client->monc);
4992 (void) ceph_monc_wait_osdmap(&rbdc->client->monc,
4993 newest_epoch,
4994 opts->mount_timeout);
4995 goto again;
4996 } else {
4997 /* the osdmap we have is new enough */
4998 return -ENOENT;
5002 return ret;
5006 * An rbd format 2 image has a unique identifier, distinct from the
5007 * name given to it by the user. Internally, that identifier is
5008 * what's used to specify the names of objects related to the image.
5010 * A special "rbd id" object is used to map an rbd image name to its
5011 * id. If that object doesn't exist, then there is no v2 rbd image
5012 * with the supplied name.
5014 * This function will record the given rbd_dev's image_id field if
5015 * it can be determined, and in that case will return 0. If any
5016 * errors occur a negative errno will be returned and the rbd_dev's
5017 * image_id field will be unchanged (and should be NULL).
5019 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
5021 int ret;
5022 size_t size;
5023 char *object_name;
5024 void *response;
5025 char *image_id;
5028 * When probing a parent image, the image id is already
5029 * known (and the image name likely is not). There's no
5030 * need to fetch the image id again in this case. We
5031 * do still need to set the image format though.
5033 if (rbd_dev->spec->image_id) {
5034 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
5036 return 0;
5040 * First, see if the format 2 image id file exists, and if
5041 * so, get the image's persistent id from it.
5043 size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
5044 object_name = kmalloc(size, GFP_NOIO);
5045 if (!object_name)
5046 return -ENOMEM;
5047 sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
5048 dout("rbd id object name is %s\n", object_name);
5050 /* Response will be an encoded string, which includes a length */
5052 size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
5053 response = kzalloc(size, GFP_NOIO);
5054 if (!response) {
5055 ret = -ENOMEM;
5056 goto out;
5059 /* If it doesn't exist we'll assume it's a format 1 image */
5061 ret = rbd_obj_method_sync(rbd_dev, object_name,
5062 "rbd", "get_id", NULL, 0,
5063 response, RBD_IMAGE_ID_LEN_MAX);
5064 dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5065 if (ret == -ENOENT) {
5066 image_id = kstrdup("", GFP_KERNEL);
5067 ret = image_id ? 0 : -ENOMEM;
5068 if (!ret)
5069 rbd_dev->image_format = 1;
5070 } else if (ret >= 0) {
5071 void *p = response;
5073 image_id = ceph_extract_encoded_string(&p, p + ret,
5074 NULL, GFP_NOIO);
5075 ret = PTR_ERR_OR_ZERO(image_id);
5076 if (!ret)
5077 rbd_dev->image_format = 2;
5080 if (!ret) {
5081 rbd_dev->spec->image_id = image_id;
5082 dout("image_id is %s\n", image_id);
5084 out:
5085 kfree(response);
5086 kfree(object_name);
5088 return ret;
5092 * Undo whatever state changes are made by v1 or v2 header info
5093 * call.
5095 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
5097 struct rbd_image_header *header;
5099 rbd_dev_parent_put(rbd_dev);
5101 /* Free dynamic fields from the header, then zero it out */
5103 header = &rbd_dev->header;
5104 ceph_put_snap_context(header->snapc);
5105 kfree(header->snap_sizes);
5106 kfree(header->snap_names);
5107 kfree(header->object_prefix);
5108 memset(header, 0, sizeof (*header));
5111 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5113 int ret;
5115 ret = rbd_dev_v2_object_prefix(rbd_dev);
5116 if (ret)
5117 goto out_err;
5120 * Get the and check features for the image. Currently the
5121 * features are assumed to never change.
5123 ret = rbd_dev_v2_features(rbd_dev);
5124 if (ret)
5125 goto out_err;
5127 /* If the image supports fancy striping, get its parameters */
5129 if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
5130 ret = rbd_dev_v2_striping_info(rbd_dev);
5131 if (ret < 0)
5132 goto out_err;
5134 /* No support for crypto and compression type format 2 images */
5136 return 0;
5137 out_err:
5138 rbd_dev->header.features = 0;
5139 kfree(rbd_dev->header.object_prefix);
5140 rbd_dev->header.object_prefix = NULL;
5142 return ret;
5146 * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
5147 * rbd_dev_image_probe() recursion depth, which means it's also the
5148 * length of the already discovered part of the parent chain.
5150 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
5152 struct rbd_device *parent = NULL;
5153 int ret;
5155 if (!rbd_dev->parent_spec)
5156 return 0;
5158 if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
5159 pr_info("parent chain is too long (%d)\n", depth);
5160 ret = -EINVAL;
5161 goto out_err;
5164 parent = rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec,
5165 NULL);
5166 if (!parent) {
5167 ret = -ENOMEM;
5168 goto out_err;
5172 * Images related by parent/child relationships always share
5173 * rbd_client and spec/parent_spec, so bump their refcounts.
5175 __rbd_get_client(rbd_dev->rbd_client);
5176 rbd_spec_get(rbd_dev->parent_spec);
5178 ret = rbd_dev_image_probe(parent, depth);
5179 if (ret < 0)
5180 goto out_err;
5182 rbd_dev->parent = parent;
5183 atomic_set(&rbd_dev->parent_ref, 1);
5184 return 0;
5186 out_err:
5187 rbd_dev_unparent(rbd_dev);
5188 if (parent)
5189 rbd_dev_destroy(parent);
5190 return ret;
5193 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5195 int ret;
5197 /* Get an id and fill in device name. */
5199 ret = rbd_dev_id_get(rbd_dev);
5200 if (ret)
5201 return ret;
5203 BUILD_BUG_ON(DEV_NAME_LEN
5204 < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
5205 sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
5207 /* Record our major and minor device numbers. */
5209 if (!single_major) {
5210 ret = register_blkdev(0, rbd_dev->name);
5211 if (ret < 0)
5212 goto err_out_id;
5214 rbd_dev->major = ret;
5215 rbd_dev->minor = 0;
5216 } else {
5217 rbd_dev->major = rbd_major;
5218 rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
5221 /* Set up the blkdev mapping. */
5223 ret = rbd_init_disk(rbd_dev);
5224 if (ret)
5225 goto err_out_blkdev;
5227 ret = rbd_dev_mapping_set(rbd_dev);
5228 if (ret)
5229 goto err_out_disk;
5231 set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
5232 set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
5234 dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
5235 ret = device_add(&rbd_dev->dev);
5236 if (ret)
5237 goto err_out_mapping;
5239 /* Everything's ready. Announce the disk to the world. */
5241 set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
5242 add_disk(rbd_dev->disk);
5244 pr_info("%s: added with size 0x%llx\n", rbd_dev->disk->disk_name,
5245 (unsigned long long) rbd_dev->mapping.size);
5247 return ret;
5249 err_out_mapping:
5250 rbd_dev_mapping_clear(rbd_dev);
5251 err_out_disk:
5252 rbd_free_disk(rbd_dev);
5253 err_out_blkdev:
5254 if (!single_major)
5255 unregister_blkdev(rbd_dev->major, rbd_dev->name);
5256 err_out_id:
5257 rbd_dev_id_put(rbd_dev);
5258 return ret;
5261 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
5263 struct rbd_spec *spec = rbd_dev->spec;
5264 size_t size;
5266 /* Record the header object name for this rbd image. */
5268 rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
5270 if (rbd_dev->image_format == 1)
5271 size = strlen(spec->image_name) + sizeof (RBD_SUFFIX);
5272 else
5273 size = sizeof (RBD_HEADER_PREFIX) + strlen(spec->image_id);
5275 rbd_dev->header_name = kmalloc(size, GFP_KERNEL);
5276 if (!rbd_dev->header_name)
5277 return -ENOMEM;
5279 if (rbd_dev->image_format == 1)
5280 sprintf(rbd_dev->header_name, "%s%s",
5281 spec->image_name, RBD_SUFFIX);
5282 else
5283 sprintf(rbd_dev->header_name, "%s%s",
5284 RBD_HEADER_PREFIX, spec->image_id);
5285 return 0;
5288 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
5290 rbd_dev_unprobe(rbd_dev);
5291 kfree(rbd_dev->header_name);
5292 rbd_dev->header_name = NULL;
5293 rbd_dev->image_format = 0;
5294 kfree(rbd_dev->spec->image_id);
5295 rbd_dev->spec->image_id = NULL;
5297 rbd_dev_destroy(rbd_dev);
5301 * Probe for the existence of the header object for the given rbd
5302 * device. If this image is the one being mapped (i.e., not a
5303 * parent), initiate a watch on its header object before using that
5304 * object to get detailed information about the rbd image.
5306 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
5308 int ret;
5311 * Get the id from the image id object. Unless there's an
5312 * error, rbd_dev->spec->image_id will be filled in with
5313 * a dynamically-allocated string, and rbd_dev->image_format
5314 * will be set to either 1 or 2.
5316 ret = rbd_dev_image_id(rbd_dev);
5317 if (ret)
5318 return ret;
5320 ret = rbd_dev_header_name(rbd_dev);
5321 if (ret)
5322 goto err_out_format;
5324 if (!depth) {
5325 ret = rbd_dev_header_watch_sync(rbd_dev);
5326 if (ret) {
5327 if (ret == -ENOENT)
5328 pr_info("image %s/%s does not exist\n",
5329 rbd_dev->spec->pool_name,
5330 rbd_dev->spec->image_name);
5331 goto out_header_name;
5335 ret = rbd_dev_header_info(rbd_dev);
5336 if (ret)
5337 goto err_out_watch;
5340 * If this image is the one being mapped, we have pool name and
5341 * id, image name and id, and snap name - need to fill snap id.
5342 * Otherwise this is a parent image, identified by pool, image
5343 * and snap ids - need to fill in names for those ids.
5345 if (!depth)
5346 ret = rbd_spec_fill_snap_id(rbd_dev);
5347 else
5348 ret = rbd_spec_fill_names(rbd_dev);
5349 if (ret) {
5350 if (ret == -ENOENT)
5351 pr_info("snap %s/%s@%s does not exist\n",
5352 rbd_dev->spec->pool_name,
5353 rbd_dev->spec->image_name,
5354 rbd_dev->spec->snap_name);
5355 goto err_out_probe;
5358 if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
5359 ret = rbd_dev_v2_parent_info(rbd_dev);
5360 if (ret)
5361 goto err_out_probe;
5364 * Need to warn users if this image is the one being
5365 * mapped and has a parent.
5367 if (!depth && rbd_dev->parent_spec)
5368 rbd_warn(rbd_dev,
5369 "WARNING: kernel layering is EXPERIMENTAL!");
5372 ret = rbd_dev_probe_parent(rbd_dev, depth);
5373 if (ret)
5374 goto err_out_probe;
5376 dout("discovered format %u image, header name is %s\n",
5377 rbd_dev->image_format, rbd_dev->header_name);
5378 return 0;
5380 err_out_probe:
5381 rbd_dev_unprobe(rbd_dev);
5382 err_out_watch:
5383 if (!depth)
5384 rbd_dev_header_unwatch_sync(rbd_dev);
5385 out_header_name:
5386 kfree(rbd_dev->header_name);
5387 rbd_dev->header_name = NULL;
5388 err_out_format:
5389 rbd_dev->image_format = 0;
5390 kfree(rbd_dev->spec->image_id);
5391 rbd_dev->spec->image_id = NULL;
5392 return ret;
5395 static ssize_t do_rbd_add(struct bus_type *bus,
5396 const char *buf,
5397 size_t count)
5399 struct rbd_device *rbd_dev = NULL;
5400 struct ceph_options *ceph_opts = NULL;
5401 struct rbd_options *rbd_opts = NULL;
5402 struct rbd_spec *spec = NULL;
5403 struct rbd_client *rbdc;
5404 bool read_only;
5405 int rc;
5407 if (!try_module_get(THIS_MODULE))
5408 return -ENODEV;
5410 /* parse add command */
5411 rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
5412 if (rc < 0)
5413 goto out;
5415 rbdc = rbd_get_client(ceph_opts);
5416 if (IS_ERR(rbdc)) {
5417 rc = PTR_ERR(rbdc);
5418 goto err_out_args;
5421 /* pick the pool */
5422 rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
5423 if (rc < 0) {
5424 if (rc == -ENOENT)
5425 pr_info("pool %s does not exist\n", spec->pool_name);
5426 goto err_out_client;
5428 spec->pool_id = (u64)rc;
5430 /* The ceph file layout needs to fit pool id in 32 bits */
5432 if (spec->pool_id > (u64)U32_MAX) {
5433 rbd_warn(NULL, "pool id too large (%llu > %u)",
5434 (unsigned long long)spec->pool_id, U32_MAX);
5435 rc = -EIO;
5436 goto err_out_client;
5439 rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
5440 if (!rbd_dev) {
5441 rc = -ENOMEM;
5442 goto err_out_client;
5444 rbdc = NULL; /* rbd_dev now owns this */
5445 spec = NULL; /* rbd_dev now owns this */
5446 rbd_opts = NULL; /* rbd_dev now owns this */
5448 rc = rbd_dev_image_probe(rbd_dev, 0);
5449 if (rc < 0)
5450 goto err_out_rbd_dev;
5452 /* If we are mapping a snapshot it must be marked read-only */
5454 read_only = rbd_dev->opts->read_only;
5455 if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
5456 read_only = true;
5457 rbd_dev->mapping.read_only = read_only;
5459 rc = rbd_dev_device_setup(rbd_dev);
5460 if (rc) {
5462 * rbd_dev_header_unwatch_sync() can't be moved into
5463 * rbd_dev_image_release() without refactoring, see
5464 * commit 1f3ef78861ac.
5466 rbd_dev_header_unwatch_sync(rbd_dev);
5467 rbd_dev_image_release(rbd_dev);
5468 goto out;
5471 rc = count;
5472 out:
5473 module_put(THIS_MODULE);
5474 return rc;
5476 err_out_rbd_dev:
5477 rbd_dev_destroy(rbd_dev);
5478 err_out_client:
5479 rbd_put_client(rbdc);
5480 err_out_args:
5481 rbd_spec_put(spec);
5482 kfree(rbd_opts);
5483 goto out;
5486 static ssize_t rbd_add(struct bus_type *bus,
5487 const char *buf,
5488 size_t count)
5490 if (single_major)
5491 return -EINVAL;
5493 return do_rbd_add(bus, buf, count);
5496 static ssize_t rbd_add_single_major(struct bus_type *bus,
5497 const char *buf,
5498 size_t count)
5500 return do_rbd_add(bus, buf, count);
5503 static void rbd_dev_device_release(struct rbd_device *rbd_dev)
5505 rbd_free_disk(rbd_dev);
5506 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
5507 device_del(&rbd_dev->dev);
5508 rbd_dev_mapping_clear(rbd_dev);
5509 if (!single_major)
5510 unregister_blkdev(rbd_dev->major, rbd_dev->name);
5511 rbd_dev_id_put(rbd_dev);
5514 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
5516 while (rbd_dev->parent) {
5517 struct rbd_device *first = rbd_dev;
5518 struct rbd_device *second = first->parent;
5519 struct rbd_device *third;
5522 * Follow to the parent with no grandparent and
5523 * remove it.
5525 while (second && (third = second->parent)) {
5526 first = second;
5527 second = third;
5529 rbd_assert(second);
5530 rbd_dev_image_release(second);
5531 first->parent = NULL;
5532 first->parent_overlap = 0;
5534 rbd_assert(first->parent_spec);
5535 rbd_spec_put(first->parent_spec);
5536 first->parent_spec = NULL;
5540 static ssize_t do_rbd_remove(struct bus_type *bus,
5541 const char *buf,
5542 size_t count)
5544 struct rbd_device *rbd_dev = NULL;
5545 struct list_head *tmp;
5546 int dev_id;
5547 unsigned long ul;
5548 bool already = false;
5549 int ret;
5551 ret = kstrtoul(buf, 10, &ul);
5552 if (ret)
5553 return ret;
5555 /* convert to int; abort if we lost anything in the conversion */
5556 dev_id = (int)ul;
5557 if (dev_id != ul)
5558 return -EINVAL;
5560 ret = -ENOENT;
5561 spin_lock(&rbd_dev_list_lock);
5562 list_for_each(tmp, &rbd_dev_list) {
5563 rbd_dev = list_entry(tmp, struct rbd_device, node);
5564 if (rbd_dev->dev_id == dev_id) {
5565 ret = 0;
5566 break;
5569 if (!ret) {
5570 spin_lock_irq(&rbd_dev->lock);
5571 if (rbd_dev->open_count)
5572 ret = -EBUSY;
5573 else
5574 already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
5575 &rbd_dev->flags);
5576 spin_unlock_irq(&rbd_dev->lock);
5578 spin_unlock(&rbd_dev_list_lock);
5579 if (ret < 0 || already)
5580 return ret;
5582 rbd_dev_header_unwatch_sync(rbd_dev);
5584 * flush remaining watch callbacks - these must be complete
5585 * before the osd_client is shutdown
5587 dout("%s: flushing notifies", __func__);
5588 ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
5591 * Don't free anything from rbd_dev->disk until after all
5592 * notifies are completely processed. Otherwise
5593 * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
5594 * in a potential use after free of rbd_dev->disk or rbd_dev.
5596 rbd_dev_device_release(rbd_dev);
5597 rbd_dev_image_release(rbd_dev);
5599 return count;
5602 static ssize_t rbd_remove(struct bus_type *bus,
5603 const char *buf,
5604 size_t count)
5606 if (single_major)
5607 return -EINVAL;
5609 return do_rbd_remove(bus, buf, count);
5612 static ssize_t rbd_remove_single_major(struct bus_type *bus,
5613 const char *buf,
5614 size_t count)
5616 return do_rbd_remove(bus, buf, count);
5620 * create control files in sysfs
5621 * /sys/bus/rbd/...
5623 static int rbd_sysfs_init(void)
5625 int ret;
5627 ret = device_register(&rbd_root_dev);
5628 if (ret < 0)
5629 return ret;
5631 ret = bus_register(&rbd_bus_type);
5632 if (ret < 0)
5633 device_unregister(&rbd_root_dev);
5635 return ret;
5638 static void rbd_sysfs_cleanup(void)
5640 bus_unregister(&rbd_bus_type);
5641 device_unregister(&rbd_root_dev);
5644 static int rbd_slab_init(void)
5646 rbd_assert(!rbd_img_request_cache);
5647 rbd_img_request_cache = kmem_cache_create("rbd_img_request",
5648 sizeof (struct rbd_img_request),
5649 __alignof__(struct rbd_img_request),
5650 0, NULL);
5651 if (!rbd_img_request_cache)
5652 return -ENOMEM;
5654 rbd_assert(!rbd_obj_request_cache);
5655 rbd_obj_request_cache = kmem_cache_create("rbd_obj_request",
5656 sizeof (struct rbd_obj_request),
5657 __alignof__(struct rbd_obj_request),
5658 0, NULL);
5659 if (!rbd_obj_request_cache)
5660 goto out_err;
5662 rbd_assert(!rbd_segment_name_cache);
5663 rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
5664 CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
5665 if (rbd_segment_name_cache)
5666 return 0;
5667 out_err:
5668 kmem_cache_destroy(rbd_obj_request_cache);
5669 rbd_obj_request_cache = NULL;
5671 kmem_cache_destroy(rbd_img_request_cache);
5672 rbd_img_request_cache = NULL;
5674 return -ENOMEM;
5677 static void rbd_slab_exit(void)
5679 rbd_assert(rbd_segment_name_cache);
5680 kmem_cache_destroy(rbd_segment_name_cache);
5681 rbd_segment_name_cache = NULL;
5683 rbd_assert(rbd_obj_request_cache);
5684 kmem_cache_destroy(rbd_obj_request_cache);
5685 rbd_obj_request_cache = NULL;
5687 rbd_assert(rbd_img_request_cache);
5688 kmem_cache_destroy(rbd_img_request_cache);
5689 rbd_img_request_cache = NULL;
5692 static int __init rbd_init(void)
5694 int rc;
5696 if (!libceph_compatible(NULL)) {
5697 rbd_warn(NULL, "libceph incompatibility (quitting)");
5698 return -EINVAL;
5701 rc = rbd_slab_init();
5702 if (rc)
5703 return rc;
5706 * The number of active work items is limited by the number of
5707 * rbd devices * queue depth, so leave @max_active at default.
5709 rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
5710 if (!rbd_wq) {
5711 rc = -ENOMEM;
5712 goto err_out_slab;
5715 if (single_major) {
5716 rbd_major = register_blkdev(0, RBD_DRV_NAME);
5717 if (rbd_major < 0) {
5718 rc = rbd_major;
5719 goto err_out_wq;
5723 rc = rbd_sysfs_init();
5724 if (rc)
5725 goto err_out_blkdev;
5727 if (single_major)
5728 pr_info("loaded (major %d)\n", rbd_major);
5729 else
5730 pr_info("loaded\n");
5732 return 0;
5734 err_out_blkdev:
5735 if (single_major)
5736 unregister_blkdev(rbd_major, RBD_DRV_NAME);
5737 err_out_wq:
5738 destroy_workqueue(rbd_wq);
5739 err_out_slab:
5740 rbd_slab_exit();
5741 return rc;
5744 static void __exit rbd_exit(void)
5746 ida_destroy(&rbd_dev_id_ida);
5747 rbd_sysfs_cleanup();
5748 if (single_major)
5749 unregister_blkdev(rbd_major, RBD_DRV_NAME);
5750 destroy_workqueue(rbd_wq);
5751 rbd_slab_exit();
5754 module_init(rbd_init);
5755 module_exit(rbd_exit);
5757 MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
5758 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
5759 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
5760 /* following authorship retained from original osdblk.c */
5761 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
5763 MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
5764 MODULE_LICENSE("GPL");