diff options
Diffstat (limited to 'drivers/block/rbd.c')
| -rw-r--r-- | drivers/block/rbd.c | 2046 |
1 files changed, 2046 insertions, 0 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c new file mode 100644 index 00000000000..e1e38b11f48 --- /dev/null +++ b/drivers/block/rbd.c @@ -0,0 +1,2046 @@ +/* + rbd.c -- Export ceph rados objects as a Linux block device + + + based on drivers/block/osdblk.c: + + Copyright 2009 Red Hat, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; see the file COPYING. If not, write to + the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + + + + For usage instructions, please refer to: + + Documentation/ABI/testing/sysfs-bus-rbd + + */ + +#include <linux/ceph/libceph.h> +#include <linux/ceph/osd_client.h> +#include <linux/ceph/mon_client.h> +#include <linux/ceph/decode.h> + +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/blkdev.h> + +#include "rbd_types.h" + +#define DRV_NAME "rbd" +#define DRV_NAME_LONG "rbd (rados block device)" + +#define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */ + +#define RBD_MAX_MD_NAME_LEN (96 + sizeof(RBD_SUFFIX)) +#define RBD_MAX_POOL_NAME_LEN 64 +#define RBD_MAX_SNAP_NAME_LEN 32 +#define RBD_MAX_OPT_LEN 1024 + +#define RBD_SNAP_HEAD_NAME "-" + +#define DEV_NAME_LEN 32 + +/* + * block device image metadata (in-memory version) + */ +struct rbd_image_header { + u64 image_size; + char block_name[32]; + __u8 obj_order; + __u8 crypt_type; + __u8 comp_type; + struct rw_semaphore snap_rwsem; + struct ceph_snap_context *snapc; + size_t snap_names_len; + u64 snap_seq; + u32 total_snaps; + + char *snap_names; + u64 *snap_sizes; +}; + +/* + * an instance of the client. multiple devices may share a client. + */ +struct rbd_client { + struct ceph_client *client; + struct kref kref; + struct list_head node; +}; + +/* + * a single io request + */ +struct rbd_request { + struct request *rq; /* blk layer request */ + struct bio *bio; /* cloned bio */ + struct page **pages; /* list of used pages */ + u64 len; +}; + +struct rbd_snap { + struct device dev; + const char *name; + size_t size; + struct list_head node; + u64 id; +}; + +/* + * a single device + */ +struct rbd_device { + int id; /* blkdev unique id */ + + int major; /* blkdev assigned major */ + struct gendisk *disk; /* blkdev's gendisk and rq */ + struct request_queue *q; + + struct ceph_client *client; + struct rbd_client *rbd_client; + + char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */ + + spinlock_t lock; /* queue lock */ + + struct rbd_image_header header; + char obj[RBD_MAX_OBJ_NAME_LEN]; /* rbd image name */ + int obj_len; + char obj_md_name[RBD_MAX_MD_NAME_LEN]; /* hdr nm. */ + char pool_name[RBD_MAX_POOL_NAME_LEN]; + int poolid; + + char snap_name[RBD_MAX_SNAP_NAME_LEN]; + u32 cur_snap; /* index+1 of current snapshot within snap context + 0 - for the head */ + int read_only; + + struct list_head node; + + /* list of snapshots */ + struct list_head snaps; + + /* sysfs related */ + struct device dev; +}; + +static struct bus_type rbd_bus_type = { + .name = "rbd", +}; + +static spinlock_t node_lock; /* protects client get/put */ + +static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */ +static LIST_HEAD(rbd_dev_list); /* devices */ +static LIST_HEAD(rbd_client_list); /* clients */ + +static int __rbd_init_snaps_header(struct rbd_device *rbd_dev); +static void rbd_dev_release(struct device *dev); +static ssize_t rbd_snap_rollback(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t size); +static ssize_t rbd_snap_add(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count); +static void __rbd_remove_snap_dev(struct rbd_device *rbd_dev, + struct rbd_snap *snap);; + + +static struct rbd_device *dev_to_rbd(struct device *dev) +{ + return container_of(dev, struct rbd_device, dev); +} + +static struct device *rbd_get_dev(struct rbd_device *rbd_dev) +{ + return get_device(&rbd_dev->dev); +} + +static void rbd_put_dev(struct rbd_device *rbd_dev) +{ + put_device(&rbd_dev->dev); +} + +static int rbd_open(struct block_device *bdev, fmode_t mode) +{ + struct gendisk *disk = bdev->bd_disk; + struct rbd_device *rbd_dev = disk->private_data; + + rbd_get_dev(rbd_dev); + + set_device_ro(bdev, rbd_dev->read_only); + + if ((mode & FMODE_WRITE) && rbd_dev->read_only) + return -EROFS; + + return 0; +} + +static int rbd_release(struct gendisk *disk, fmode_t mode) +{ + struct rbd_device *rbd_dev = disk->private_data; + + rbd_put_dev(rbd_dev); + + return 0; +} + +static const struct block_device_operations rbd_bd_ops = { + .owner = THIS_MODULE, + .open = rbd_open, + .release = rbd_release, +}; + +/* + * Initialize an rbd client instance. + * We own *opt. + */ +static struct rbd_client *rbd_client_create(struct ceph_options *opt) +{ + struct rbd_client *rbdc; + int ret = -ENOMEM; + + dout("rbd_client_create\n"); + rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL); + if (!rbdc) + goto out_opt; + + kref_init(&rbdc->kref); + INIT_LIST_HEAD(&rbdc->node); + + rbdc->client = ceph_create_client(opt, rbdc); + if (IS_ERR(rbdc->client)) + goto out_rbdc; + opt = NULL; /* Now rbdc->client is responsible for opt */ + + ret = ceph_open_session(rbdc->client); + if (ret < 0) + goto out_err; + + spin_lock(&node_lock); + list_add_tail(&rbdc->node, &rbd_client_list); + spin_unlock(&node_lock); + + dout("rbd_client_create created %p\n", rbdc); + return rbdc; + +out_err: + ceph_destroy_client(rbdc->client); +out_rbdc: + kfree(rbdc); +out_opt: + if (opt) + ceph_destroy_options(opt); + return ERR_PTR(ret); +} + +/* + * Find a ceph client with specific addr and configuration. + */ +static struct rbd_client *__rbd_client_find(struct ceph_options *opt) +{ + struct rbd_client *client_node; + + if (opt->flags & CEPH_OPT_NOSHARE) + return NULL; + + list_for_each_entry(client_node, &rbd_client_list, node) + if (ceph_compare_options(opt, client_node->client) == 0) + return client_node; + return NULL; +} + +/* + * Get a ceph client with specific addr and configuration, if one does + * not exist create it. + */ +static int rbd_get_client(struct rbd_device *rbd_dev, const char *mon_addr, + char *options) +{ + struct rbd_client *rbdc; + struct ceph_options *opt; + int ret; + + ret = ceph_parse_options(&opt, options, mon_addr, + mon_addr + strlen(mon_addr), NULL, NULL); + if (ret < 0) + return ret; + + spin_lock(&node_lock); + rbdc = __rbd_client_find(opt); + if (rbdc) { + ceph_destroy_options(opt); + + /* using an existing client */ + kref_get(&rbdc->kref); + rbd_dev->rbd_client = rbdc; + rbd_dev->client = rbdc->client; + spin_unlock(&node_lock); + return 0; + } + spin_unlock(&node_lock); + + rbdc = rbd_client_create(opt); + if (IS_ERR(rbdc)) + return PTR_ERR(rbdc); + + rbd_dev->rbd_client = rbdc; + rbd_dev->client = rbdc->client; + return 0; +} + +/* + * Destroy ceph client + */ +static void rbd_client_release(struct kref *kref) +{ + struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref); + + dout("rbd_release_client %p\n", rbdc); + spin_lock(&node_lock); + list_del(&rbdc->node); + spin_unlock(&node_lock); + + ceph_destroy_client(rbdc->client); + kfree(rbdc); +} + +/* + * Drop reference to ceph client node. If it's not referenced anymore, release + * it. + */ +static void rbd_put_client(struct rbd_device *rbd_dev) +{ + kref_put(&rbd_dev->rbd_client->kref, rbd_client_release); + rbd_dev->rbd_client = NULL; + rbd_dev->client = NULL; +} + + +/* + * Create a new header structure, translate header format from the on-disk + * header. + */ +static int rbd_header_from_disk(struct rbd_image_header *header, + struct rbd_image_header_ondisk *ondisk, + int allocated_snaps, + gfp_t gfp_flags) +{ + int i; + u32 snap_count = le32_to_cpu(ondisk->snap_count); + int ret = -ENOMEM; + + init_rwsem(&header->snap_rwsem); + header->snap_names_len = le64_to_cpu(ondisk->snap_names_len); + header->snapc = kmalloc(sizeof(struct ceph_snap_context) + + snap_count * + sizeof(struct rbd_image_snap_ondisk), + gfp_flags); + if (!header->snapc) + return -ENOMEM; + if (snap_count) { + header->snap_names = kmalloc(header->snap_names_len, + GFP_KERNEL); + if (!header->snap_names) + goto err_snapc; + header->snap_sizes = kmalloc(snap_count * sizeof(u64), + GFP_KERNEL); + if (!header->snap_sizes) + goto err_names; + } else { + header->snap_names = NULL; + header->snap_sizes = NULL; + } + memcpy(header->block_name, ondisk->block_name, + sizeof(ondisk->block_name)); + + header->image_size = le64_to_cpu(ondisk->image_size); + header->obj_order = ondisk->options.order; + header->crypt_type = ondisk->options.crypt_type; + header->comp_type = ondisk->options.comp_type; + + atomic_set(&header->snapc->nref, 1); + header->snap_seq = le64_to_cpu(ondisk->snap_seq); + header->snapc->num_snaps = snap_count; + header->total_snaps = snap_count; + + if (snap_count && + allocated_snaps == snap_count) { + for (i = 0; i < snap_count; i++) { + header->snapc->snaps[i] = + le64_to_cpu(ondisk->snaps[i].id); + header->snap_sizes[i] = + le64_to_cpu(ondisk->snaps[i].image_size); + } + + /* copy snapshot names */ + memcpy(header->snap_names, &ondisk->snaps[i], + header->snap_names_len); + } + + return 0; + +err_names: + kfree(header->snap_names); +err_snapc: + kfree(header->snapc); + return ret; +} + +static int snap_index(struct rbd_image_header *header, int snap_num) +{ + return header->total_snaps - snap_num; +} + +static u64 cur_snap_id(struct rbd_device *rbd_dev) +{ + struct rbd_image_header *header = &rbd_dev->header; + + if (!rbd_dev->cur_snap) + return 0; + + return header->snapc->snaps[snap_index(header, rbd_dev->cur_snap)]; +} + +static int snap_by_name(struct rbd_image_header *header, const char *snap_name, + u64 *seq, u64 *size) +{ + int i; + char *p = header->snap_names; + + for (i = 0; i < header->total_snaps; i++, p += strlen(p) + 1) { + if (strcmp(snap_name, p) == 0) + break; + } + if (i == header->total_snaps) + return -ENOENT; + if (seq) + *seq = header->snapc->snaps[i]; + + if (size) + *size = header->snap_sizes[i]; + + return i; +} + +static int rbd_header_set_snap(struct rbd_device *dev, + const char *snap_name, + u64 *size) +{ + struct rbd_image_header *header = &dev->header; + struct ceph_snap_context *snapc = header->snapc; + int ret = -ENOENT; + + down_write(&header->snap_rwsem); + + if (!snap_name || + !*snap_name || + strcmp(snap_name, "-") == 0 || + strcmp(snap_name, RBD_SNAP_HEAD_NAME) == 0) { + if (header->total_snaps) + snapc->seq = header->snap_seq; + else + snapc->seq = 0; + dev->cur_snap = 0; + dev->read_only = 0; + if (size) + *size = header->image_size; + } else { + ret = snap_by_name(header, snap_name, &snapc->seq, size); + if (ret < 0) + goto done; + + dev->cur_snap = header->total_snaps - ret; + dev->read_only = 1; + } + + ret = 0; +done: + up_write(&header->snap_rwsem); + return ret; +} + +static void rbd_header_free(struct rbd_image_header *header) +{ + kfree(header->snapc); + kfree(header->snap_names); + kfree(header->snap_sizes); +} + +/* + * get the actual striped segment name, offset and length + */ +static u64 rbd_get_segment(struct rbd_image_header *header, + const char *block_name, + u64 ofs, u64 len, + char *seg_name, u64 *segofs) +{ + u64 seg = ofs >> header->obj_order; + + if (seg_name) + snprintf(seg_name, RBD_MAX_SEG_NAME_LEN, + "%s.%012llx", block_name, seg); + + ofs = ofs & ((1 << header->obj_order) - 1); + len = min_t(u64, len, (1 << header->obj_order) - ofs); + + if (segofs) + *segofs = ofs; + + return len; +} + +/* + * bio helpers + */ + +static void bio_chain_put(struct bio *chain) +{ + struct bio *tmp; + + while (chain) { + tmp = chain; + chain = chain->bi_next; + bio_put(tmp); + } +} + +/* + * zeros a bio chain, starting at specific offset + */ +static void zero_bio_chain(struct bio *chain, int start_ofs) +{ + struct bio_vec *bv; + unsigned long flags; + void *buf; + int i; + int pos = 0; + + while (chain) { + bio_for_each_segment(bv, chain, i) { + if (pos + bv->bv_len > start_ofs) { + int remainder = max(start_ofs - pos, 0); + buf = bvec_kmap_irq(bv, &flags); + memset(buf + remainder, 0, + bv->bv_len - remainder); + bvec_kunmap_irq(buf, &flags); + } + pos += bv->bv_len; + } + + chain = chain->bi_next; + } +} + +/* + * bio_chain_clone - clone a chain of bios up to a certain length. + * might return a bio_pair that will need to be released. + */ +static struct bio *bio_chain_clone(struct bio **old, struct bio **next, + struct bio_pair **bp, + int len, gfp_t gfpmask) +{ + struct bio *tmp, *old_chain = *old, *new_chain = NULL, *tail = NULL; + int total = 0; + + if (*bp) { + bio_pair_release(*bp); + *bp = NULL; + } + + while (old_chain && (total < len)) { + tmp = bio_kmalloc(gfpmask, old_chain->bi_max_vecs); + if (!tmp) + goto err_out; + + if (total + old_chain->bi_size > len) { + struct bio_pair *bp; + + /* + * this split can only happen with a single paged bio, + * split_bio will BUG_ON if this is not the case + */ + dout("bio_chain_clone split! total=%d remaining=%d" + "bi_size=%d\n", + (int)total, (int)len-total, + (int)old_chain->bi_size); + + /* split the bio. We'll release it either in the next + call, or it will have to be released outside */ + bp = bio_split(old_chain, (len - total) / 512ULL); + if (!bp) + goto err_out; + + __bio_clone(tmp, &bp->bio1); + + *next = &bp->bio2; + } else { + __bio_clone(tmp, old_chain); + *next = old_chain->bi_next; + } + + tmp->bi_bdev = NULL; + gfpmask &= ~__GFP_WAIT; + tmp->bi_next = NULL; + + if (!new_chain) { + new_chain = tail = tmp; + } else { + tail->bi_next = tmp; + tail = tmp; + } + old_chain = old_chain->bi_next; + + total += tmp->bi_size; + } + + BUG_ON(total < len); + + if (tail) + tail->bi_next = NULL; + + *old = old_chain; + + return new_chain; + +err_out: + dout("bio_chain_clone with err\n"); + bio_chain_put(new_chain); + return NULL; +} + +/* + * helpers for osd request op vectors. + */ +static int rbd_create_rw_ops(struct ceph_osd_req_op **ops, + int num_ops, + int opcode, + u32 payload_len) +{ + *ops = kzalloc(sizeof(struct ceph_osd_req_op) * (num_ops + 1), + GFP_NOIO); + if (!*ops) + return -ENOMEM; + (*ops)[0].op = opcode; + /* + * op extent offset and length will be set later on + * in calc_raw_layout() + */ + (*ops)[0].payload_len = payload_len; + return 0; +} + +static void rbd_destroy_ops(struct ceph_osd_req_op *ops) +{ + kfree(ops); +} + +/* + * Send ceph osd request + */ +static int rbd_do_request(struct request *rq, + struct rbd_device *dev, + struct ceph_snap_context *snapc, + u64 snapid, + const char *obj, u64 ofs, u64 len, + struct bio *bio, + struct page **pages, + int num_pages, + int flags, + struct ceph_osd_req_op *ops, + int num_reply, + void (*rbd_cb)(struct ceph_osd_request *req, + struct ceph_msg *msg)) +{ + struct ceph_osd_request *req; + struct ceph_file_layout *layout; + int ret; + u64 bno; + struct timespec mtime = CURRENT_TIME; + struct rbd_request *req_data; + struct ceph_osd_request_head *reqhead; + struct rbd_image_header *header = &dev->header; + + ret = -ENOMEM; + req_data = kzalloc(sizeof(*req_data), GFP_NOIO); + if (!req_data) + goto done; + + dout("rbd_do_request len=%lld ofs=%lld\n", len, ofs); + + down_read(&header->snap_rwsem); + + req = ceph_osdc_alloc_request(&dev->client->osdc, flags, + snapc, + ops, + false, + GFP_NOIO, pages, bio); + if (IS_ERR(req)) { + up_read(&header->snap_rwsem); + ret = PTR_ERR(req); + goto done_pages; + } + + req->r_callback = rbd_cb; + + req_data->rq = rq; + req_data->bio = bio; + req_data->pages = pages; + req_data->len = len; + + req->r_priv = req_data; + + reqhead = req->r_request->front.iov_base; + reqhead->snapid = cpu_to_le64(CEPH_NOSNAP); + + strncpy(req->r_oid, obj, sizeof(req->r_oid)); + req->r_oid_len = strlen(req->r_oid); + + layout = &req->r_file_layout; + memset(layout, 0, sizeof(*layout)); + layout->fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER); + layout->fl_stripe_count = cpu_to_le32(1); + layout->fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER); + layout->fl_pg_preferred = cpu_to_le32(-1); + layout->fl_pg_pool = cpu_to_le32(dev->poolid); + ceph_calc_raw_layout(&dev->client->osdc, layout, snapid, + ofs, &len, &bno, req, ops); + + ceph_osdc_build_request(req, ofs, &len, + ops, + snapc, + &mtime, + req->r_oid, req->r_oid_len); + up_read(&header->snap_rwsem); + + ret = ceph_osdc_start_request(&dev->client->osdc, req, false); + if (ret < 0) + goto done_err; + + if (!rbd_cb) { + ret = ceph_osdc_wait_request(&dev->client->osdc, req); + ceph_osdc_put_request(req); + } + return ret; + +done_err: + bio_chain_put(req_data->bio); + ceph_osdc_put_request(req); +done_pages: + kfree(req_data); +done: + if (rq) + blk_end_request(rq, ret, len); + return ret; +} + +/* + * Ceph osd op callback + */ +static void rbd_req_cb(struct ceph_osd_request *req, struct ceph_msg *msg) +{ + struct rbd_request *req_data = req->r_priv; + struct ceph_osd_reply_head *replyhead; + struct ceph_osd_op *op; + __s32 rc; + u64 bytes; + int read_op; + + /* parse reply */ + replyhead = msg->front.iov_base; + WARN_ON(le32_to_cpu(replyhead->num_ops) == 0); + op = (void *)(replyhead + 1); + rc = le32_to_cpu(replyhead->result); + bytes = le64_to_cpu(op->extent.length); + read_op = (le32_to_cpu(op->op) == CEPH_OSD_OP_READ); + + dout("rbd_req_cb bytes=%lld readop=%d rc=%d\n", bytes, read_op, rc); + + if (rc == -ENOENT && read_op) { + zero_bio_chain(req_data->bio, 0); + rc = 0; + } else if (rc == 0 && read_op && bytes < req_data->len) { + zero_bio_chain(req_data->bio, bytes); + bytes = req_data->len; + } + + blk_end_request(req_data->rq, rc, bytes); + + if (req_data->bio) + bio_chain_put(req_data->bio); + + ceph_osdc_put_request(req); + kfree(req_data); +} + +/* + * Do a synchronous ceph osd operation + */ +static int rbd_req_sync_op(struct rbd_device *dev, + struct ceph_snap_context *snapc, + u64 snapid, + int opcode, + int flags, + struct ceph_osd_req_op *orig_ops, + int num_reply, + const char *obj, + u64 ofs, u64 len, + char *buf) +{ + int ret; + struct page **pages; + int num_pages; + struct ceph_osd_req_op *ops = orig_ops; + u32 payload_len; + + num_pages = calc_pages_for(ofs , len); + pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL); + if (IS_ERR(pages)) + return PTR_ERR(pages); + + if (!orig_ops) { + payload_len = (flags & CEPH_OSD_FLAG_WRITE ? len : 0); + ret = rbd_create_rw_ops(&ops, 1, opcode, payload_len); + if (ret < 0) + goto done; + + if ((flags & CEPH_OSD_FLAG_WRITE) && buf) { + ret = ceph_copy_to_page_vector(pages, buf, ofs, len); + if (ret < 0) + goto done_ops; + } + } + + ret = rbd_do_request(NULL, dev, snapc, snapid, + obj, ofs, len, NULL, + pages, num_pages, + flags, + ops, + 2, + NULL); + if (ret < 0) + goto done_ops; + + if ((flags & CEPH_OSD_FLAG_READ) && buf) + ret = ceph_copy_from_page_vector(pages, buf, ofs, ret); + +done_ops: + if (!orig_ops) + rbd_destroy_ops(ops); +done: + ceph_release_page_vector(pages, num_pages); + return ret; +} + +/* + * Do an asynchronous ceph osd operation + */ +static int rbd_do_op(struct request *rq, + struct rbd_device *rbd_dev , + struct ceph_snap_context *snapc, + u64 snapid, + int opcode, int flags, int num_reply, + u64 ofs, u64 len, + struct bio *bio) +{ + char *seg_name; + u64 seg_ofs; + u64 seg_len; + int ret; + struct ceph_osd_req_op *ops; + u32 payload_len; + + seg_name = kmalloc(RBD_MAX_SEG_NAME_LEN + 1, GFP_NOIO); + if (!seg_name) + return -ENOMEM; + + seg_len = rbd_get_segment(&rbd_dev->header, + rbd_dev->header.block_name, + ofs, len, + seg_name, &seg_ofs); + + payload_len = (flags & CEPH_OSD_FLAG_WRITE ? seg_len : 0); + + ret = rbd_create_rw_ops(&ops, 1, opcode, payload_len); + if (ret < 0) + goto done; + + /* we've taken care of segment sizes earlier when we + cloned the bios. We should never have a segment + truncated at this point */ + BUG_ON(seg_len < len); + + ret = rbd_do_request(rq, rbd_dev, snapc, snapid, + seg_name, seg_ofs, seg_len, + bio, + NULL, 0, + flags, + ops, + num_reply, + rbd_req_cb); +done: + kfree(seg_name); + return ret; +} + +/* + * Request async osd write + */ +static int rbd_req_write(struct request *rq, + struct rbd_device *rbd_dev, + struct ceph_snap_context *snapc, + u64 ofs, u64 len, + struct bio *bio) +{ + return rbd_do_op(rq, rbd_dev, snapc, CEPH_NOSNAP, + CEPH_OSD_OP_WRITE, + CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK, + 2, + ofs, len, bio); +} + +/* + * Request async osd read + */ +static int rbd_req_read(struct request *rq, + struct rbd_device *rbd_dev, + u64 snapid, + u64 ofs, u64 len, + struct bio *bio) +{ + return rbd_do_op(rq, rbd_dev, NULL, + (snapid ? snapid : CEPH_NOSNAP), + CEPH_OSD_OP_READ, + CEPH_OSD_FLAG_READ, + 2, + ofs, len, bio); +} + +/* + * Request sync osd read + */ +static int rbd_req_sync_read(struct rbd_device *dev, + struct ceph_snap_context *snapc, + u64 snapid, + const char *obj, + u64 ofs, u64 len, + char *buf) +{ + return rbd_req_sync_op(dev, NULL, + (snapid ? snapid : CEPH_NOSNAP), + CEPH_OSD_OP_READ, + CEPH_OSD_FLAG_READ, + NULL, + 1, obj, ofs, len, buf); +} + +/* + * Request sync osd read + */ +static int rbd_req_sync_rollback_obj(struct rbd_device *dev, + u64 snapid, + const char *obj) +{ + struct ceph_osd_req_op *ops; + int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_ROLLBACK, 0); + if (ret < 0) + return ret; + + ops[0].snap.snapid = snapid; + + ret = rbd_req_sync_op(dev, NULL, + CEPH_NOSNAP, + 0, + CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK, + ops, + 1, obj, 0, 0, NULL); + + rbd_destroy_ops(ops); + + if (ret < 0) + return ret; + + return ret; +} + +/* + * Request sync osd read + */ +static int rbd_req_sync_exec(struct rbd_device *dev, + const char *obj, + const char *cls, + const char *method, + const char *data, + int len) +{ + struct ceph_osd_req_op *ops; + int cls_len = strlen(cls); + int method_len = strlen(method); + int ret = rbd_create_rw_ops(&ops, 1, CEPH_OSD_OP_CALL, + cls_len + method_len + len); + if (ret < 0) + return ret; + + ops[0].cls.class_name = cls; + ops[0].cls.class_len = (__u8)cls_len; + ops[0].cls.method_name = method; + ops[0].cls.method_len = (__u8)method_len; + ops[0].cls.argc = 0; + ops[0].cls.indata = data; + ops[0].cls.indata_len = len; + + ret = rbd_req_sync_op(dev, NULL, + CEPH_NOSNAP, + 0, + CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK, + ops, + 1, obj, 0, 0, NULL); + + rbd_destroy_ops(ops); + + dout("cls_exec returned %d\n", ret); + return ret; +} + +/* + * block device queue callback + */ +static void rbd_rq_fn(struct request_queue *q) +{ + struct rbd_device *rbd_dev = q->queuedata; + struct request *rq; + struct bio_pair *bp = NULL; + + rq = blk_fetch_request(q); + + while (1) { + struct bio *bio; + struct bio *rq_bio, *next_bio = NULL; + bool do_write; + int size, op_size = 0; + u64 ofs; + + /* peek at request from block layer */ + if (!rq) + break; + + dout("fetched request\n"); + + /* filter out block requests we don't understand */ + if ((rq->cmd_type != REQ_TYPE_FS)) { + __blk_end_request_all(rq, 0); + goto next; + } + + /* deduce our operation (read, write) */ + do_write = (rq_data_dir(rq) == WRITE); + + size = blk_rq_bytes(rq); + ofs = blk_rq_pos(rq) * 512ULL; + rq_bio = rq->bio; + if (do_write && rbd_dev->read_only) { + __blk_end_request_all(rq, -EROFS); + goto next; + } + + spin_unlock_irq(q->queue_lock); + + dout("%s 0x%x bytes at 0x%llx\n", + do_write ? "write" : "read", + size, blk_rq_pos(rq) * 512ULL); + + do { + /* a bio clone to be passed down to OSD req */ + dout("rq->bio->bi_vcnt=%d\n", rq->bio->bi_vcnt); + op_size = rbd_get_segment(&rbd_dev->header, + rbd_dev->header.block_name, + ofs, size, + NULL, NULL); + bio = bio_chain_clone(&rq_bio, &next_bio, &bp, + op_size, GFP_ATOMIC); + if (!bio) { + spin_lock_irq(q->queue_lock); + __blk_end_request_all(rq, -ENOMEM); + goto next; + } + + /* init OSD command: write or read */ + if (do_write) + rbd_req_write(rq, rbd_dev, + rbd_dev->header.snapc, + ofs, + op_size, bio); + else + rbd_req_read(rq, rbd_dev, + cur_snap_id(rbd_dev), + ofs, + op_size, bio); + + size -= op_size; + ofs += op_size; + + rq_bio = next_bio; + } while (size > 0); + + if (bp) + bio_pair_release(bp); + + spin_lock_irq(q->queue_lock); +next: + rq = blk_fetch_request(q); + } +} + +/* + * a queue callback. Makes sure that we don't create a bio that spans across + * multiple osd objects. One exception would be with a single page bios, + * which we handle later at bio_chain_clone + */ +static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd, + struct bio_vec *bvec) +{ + struct rbd_device *rbd_dev = q->queuedata; + unsigned int chunk_sectors = 1 << (rbd_dev->header.obj_order - 9); + sector_t sector = bmd->bi_sector + get_start_sect(bmd->bi_bdev); + unsigned int bio_sectors = bmd->bi_size >> 9; + int max; + + max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + + bio_sectors)) << 9; + if (max < 0) + max = 0; /* bio_add cannot handle a negative return */ + if (max <= bvec->bv_len && bio_sectors == 0) + return bvec->bv_len; + return max; +} + +static void rbd_free_disk(struct rbd_device *rbd_dev) +{ + struct gendisk *disk = rbd_dev->disk; + + if (!disk) + return; + + rbd_header_free(&rbd_dev->header); + + if (disk->flags & GENHD_FL_UP) + del_gendisk(disk); + if (disk->queue) + blk_cleanup_queue(disk->queue); + put_disk(disk); +} + +/* + * reload the ondisk the header + */ +static int rbd_read_header(struct rbd_device *rbd_dev, + struct rbd_image_header *header) +{ + ssize_t rc; + struct rbd_image_header_ondisk *dh; + int snap_count = 0; + u64 snap_names_len = 0; + + while (1) { + int len = sizeof(*dh) + + snap_count * sizeof(struct rbd_image_snap_ondisk) + + snap_names_len; + + rc = -ENOMEM; + dh = kmalloc(len, GFP_KERNEL); + if (!dh) + return -ENOMEM; + + rc = rbd_req_sync_read(rbd_dev, + NULL, CEPH_NOSNAP, + rbd_dev->obj_md_name, + 0, len, + (char *)dh); + if (rc < 0) + goto out_dh; + + rc = rbd_header_from_disk(header, dh, snap_count, GFP_KERNEL); + if (rc < 0) + goto out_dh; + + if (snap_count != header->total_snaps) { + snap_count = header->total_snaps; + snap_names_len = header->snap_names_len; + rbd_header_free(header); + kfree(dh); + continue; + } + break; + } + +out_dh: + kfree(dh); + return rc; +} + +/* + * create a snapshot + */ +static int rbd_header_add_snap(struct rbd_device *dev, + const char *snap_name, + gfp_t gfp_flags) +{ + int name_len = strlen(snap_name); + u64 new_snapid; + int ret; + void *data, *data_start, *data_end; + + /* we should create a snapshot only if we're pointing at the head */ + if (dev->cur_snap) + return -EINVAL; + + ret = ceph_monc_create_snapid(&dev->client->monc, dev->poolid, + &new_snapid); + dout("created snapid=%lld\n", new_snapid); + if (ret < 0) + return ret; + + data = kmalloc(name_len + 16, gfp_flags); + if (!data) + return -ENOMEM; + + data_start = data; + data_end = data + name_len + 16; + + ceph_encode_string_safe(&data, data_end, snap_name, name_len, bad); + ceph_encode_64_safe(&data, data_end, new_snapid, bad); + + ret = rbd_req_sync_exec(dev, dev->obj_md_name, "rbd", "snap_add", + data_start, data - data_start); + + kfree(data_start); + + if (ret < 0) + return ret; + + dev->header.snapc->seq = new_snapid; + + return 0; +bad: + return -ERANGE; +} + +static void __rbd_remove_all_snaps(struct rbd_device *rbd_dev) +{ + struct rbd_snap *snap; + + while (!list_empty(&rbd_dev->snaps)) { + snap = list_first_entry(&rbd_dev->snaps, struct rbd_snap, node); + __rbd_remove_snap_dev(rbd_dev, snap); + } +} + +/* + * only read the first part of the ondisk header, without the snaps info + */ +static int __rbd_update_snaps(struct rbd_device *rbd_dev) +{ + int ret; + struct rbd_image_header h; + u64 snap_seq; + + ret = rbd_read_header(rbd_dev, &h); + if (ret < 0) + return ret; + + down_write(&rbd_dev->header.snap_rwsem); + + snap_seq = rbd_dev->header.snapc->seq; + + kfree(rbd_dev->header.snapc); + kfree(rbd_dev->header.snap_names); + kfree(rbd_dev->header.snap_sizes); + + rbd_dev->header.total_snaps = h.total_snaps; + rbd_dev->header.snapc = h.snapc; + rbd_dev->header.snap_names = h.snap_names; + rbd_dev->header.snap_names_len = h.snap_names_len; + rbd_dev->header.snap_sizes = h.snap_sizes; + rbd_dev->header.snapc->seq = snap_seq; + + ret = __rbd_init_snaps_header(rbd_dev); + + up_write(&rbd_dev->header.snap_rwsem); + + return ret; +} + +static int rbd_init_disk(struct rbd_device *rbd_dev) +{ + struct gendisk *disk; + struct request_queue *q; + int rc; + u64 total_size = 0; + + /* contact OSD, request size info about the object being mapped */ + rc = rbd_read_header(rbd_dev, &rbd_dev->header); + if (rc) + return rc; + + /* no need to lock here, as rbd_dev is not registered yet */ + rc = __rbd_init_snaps_header(rbd_dev); + if (rc) + return rc; + + rc = rbd_header_set_snap(rbd_dev, rbd_dev->snap_name, &total_size); + if (rc) + return rc; + + /* create gendisk info */ + rc = -ENOMEM; + disk = alloc_disk(RBD_MINORS_PER_MAJOR); + if (!disk) + goto out; + + sprintf(disk->disk_name, DRV_NAME "%d", rbd_dev->id); + disk->major = rbd_dev->major; + disk->first_minor = 0; + disk->fops = &rbd_bd_ops; + disk->private_data = rbd_dev; + + /* init rq */ + rc = -ENOMEM; + q = blk_init_queue(rbd_rq_fn, &rbd_dev->lock); + if (!q) + goto out_disk; + blk_queue_merge_bvec(q, rbd_merge_bvec); + disk->queue = q; + + q->queuedata = rbd_dev; + + rbd_dev->disk = disk; + rbd_dev->q = q; + + /* finally, announce the disk to the world */ + set_capacity(disk, total_size / 512ULL); + add_disk(disk); + + pr_info("%s: added with size 0x%llx\n", + disk->disk_name, (unsigned long long)total_size); + return 0; + +out_disk: + put_disk(disk); +out: + return rc; +} + +/* + sysfs +*/ + +static ssize_t rbd_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + + return sprintf(buf, "%llu\n", (unsigned long long)rbd_dev->header.image_size); +} + +static ssize_t rbd_major_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + + return sprintf(buf, "%d\n", rbd_dev->major); +} + +static ssize_t rbd_client_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + + return sprintf(buf, "client%lld\n", ceph_client_id(rbd_dev->client)); +} + +static ssize_t rbd_pool_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + + return sprintf(buf, "%s\n", rbd_dev->pool_name); +} + +static ssize_t rbd_name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + + return sprintf(buf, "%s\n", rbd_dev->obj); +} + +static ssize_t rbd_snap_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + + return sprintf(buf, "%s\n", rbd_dev->snap_name); +} + +static ssize_t rbd_image_refresh(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t size) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + int rc; + int ret = size; + + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + + rc = __rbd_update_snaps(rbd_dev); + if (rc < 0) + ret = rc; + + mutex_unlock(&ctl_mutex); + return ret; +} + +static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL); +static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL); +static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL); +static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL); +static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL); +static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh); +static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL); +static DEVICE_ATTR(create_snap, S_IWUSR, NULL, rbd_snap_add); +static DEVICE_ATTR(rollback_snap, S_IWUSR, NULL, rbd_snap_rollback); + +static struct attribute *rbd_attrs[] = { + &dev_attr_size.attr, + &dev_attr_major.attr, + &dev_attr_client_id.attr, + &dev_attr_pool.attr, + &dev_attr_name.attr, + &dev_attr_current_snap.attr, + &dev_attr_refresh.attr, + &dev_attr_create_snap.attr, + &dev_attr_rollback_snap.attr, + NULL +}; + +static struct attribute_group rbd_attr_group = { + .attrs = rbd_attrs, +}; + +static const struct attribute_group *rbd_attr_groups[] = { + &rbd_attr_group, + NULL +}; + +static void rbd_sysfs_dev_release(struct device *dev) +{ +} + +static struct device_type rbd_device_type = { + .name = "rbd", + .groups = rbd_attr_groups, + .release = rbd_sysfs_dev_release, +}; + + +/* + sysfs - snapshots +*/ + +static ssize_t rbd_snap_size_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev); + + return sprintf(buf, "%lld\n", (long long)snap->size); +} + +static ssize_t rbd_snap_id_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev); + + return sprintf(buf, "%lld\n", (long long)snap->id); +} + +static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL); +static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL); + +static struct attribute *rbd_snap_attrs[] = { + &dev_attr_snap_size.attr, + &dev_attr_snap_id.attr, + NULL, +}; + +static struct attribute_group rbd_snap_attr_group = { + .attrs = rbd_snap_attrs, +}; + +static void rbd_snap_dev_release(struct device *dev) +{ + struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev); + kfree(snap->name); + kfree(snap); +} + +static const struct attribute_group *rbd_snap_attr_groups[] = { + &rbd_snap_attr_group, + NULL +}; + +static struct device_type rbd_snap_device_type = { + .groups = rbd_snap_attr_groups, + .release = rbd_snap_dev_release, +}; + +static void __rbd_remove_snap_dev(struct rbd_device *rbd_dev, + struct rbd_snap *snap) +{ + list_del(&snap->node); + device_unregister(&snap->dev); +} + +static int rbd_register_snap_dev(struct rbd_device *rbd_dev, + struct rbd_snap *snap, + struct device *parent) +{ + struct device *dev = &snap->dev; + int ret; + + dev->type = &rbd_snap_device_type; + dev->parent = parent; + dev->release = rbd_snap_dev_release; + dev_set_name(dev, "snap_%s", snap->name); + ret = device_register(dev); + + return ret; +} + +static int __rbd_add_snap_dev(struct rbd_device *rbd_dev, + int i, const char *name, + struct rbd_snap **snapp) +{ + int ret; + struct rbd_snap *snap = kzalloc(sizeof(*snap), GFP_KERNEL); + if (!snap) + return -ENOMEM; + snap->name = kstrdup(name, GFP_KERNEL); + snap->size = rbd_dev->header.snap_sizes[i]; + snap->id = rbd_dev->header.snapc->snaps[i]; + if (device_is_registered(&rbd_dev->dev)) { + ret = rbd_register_snap_dev(rbd_dev, snap, + &rbd_dev->dev); + if (ret < 0) + goto err; + } + *snapp = snap; + return 0; +err: + kfree(snap->name); + kfree(snap); + return ret; +} + +/* + * search for the previous snap in a null delimited string list + */ +const char *rbd_prev_snap_name(const char *name, const char *start) +{ + if (name < start + 2) + return NULL; + + name -= 2; + while (*name) { + if (name == start) + return start; + name--; + } + return name + 1; +} + +/* + * compare the old list of snapshots that we have to what's in the header + * and update it accordingly. Note that the header holds the snapshots + * in a reverse order (from newest to oldest) and we need to go from + * older to new so that we don't get a duplicate snap name when + * doing the process (e.g., removed snapshot and recreated a new + * one with the same name. + */ +static int __rbd_init_snaps_header(struct rbd_device *rbd_dev) +{ + const char *name, *first_name; + int i = rbd_dev->header.total_snaps; + struct rbd_snap *snap, *old_snap = NULL; + int ret; + struct list_head *p, *n; + + first_name = rbd_dev->header.snap_names; + name = first_name + rbd_dev->header.snap_names_len; + + list_for_each_prev_safe(p, n, &rbd_dev->snaps) { + u64 cur_id; + + old_snap = list_entry(p, struct rbd_snap, node); + + if (i) + cur_id = rbd_dev->header.snapc->snaps[i - 1]; + + if (!i || old_snap->id < cur_id) { + /* old_snap->id was skipped, thus was removed */ + __rbd_remove_snap_dev(rbd_dev, old_snap); + continue; + } + if (old_snap->id == cur_id) { + /* we have this snapshot already */ + i--; + name = rbd_prev_snap_name(name, first_name); + continue; + } + for (; i > 0; + i--, name = rbd_prev_snap_name(name, first_name)) { + if (!name) { + WARN_ON(1); + return -EINVAL; + } + cur_id = rbd_dev->header.snapc->snaps[i]; + /* snapshot removal? handle it above */ + if (cur_id >= old_snap->id) + break; + /* a new snapshot */ + ret = __rbd_add_snap_dev(rbd_dev, i - 1, name, &snap); + if (ret < 0) + return ret; + + /* note that we add it backward so using n and not p */ + list_add(&snap->node, n); + p = &snap->node; + } + } + /* we're done going over the old snap list, just add what's left */ + for (; i > 0; i--) { + name = rbd_prev_snap_name(name, first_name); + if (!name) { + WARN_ON(1); + return -EINVAL; + } + ret = __rbd_add_snap_dev(rbd_dev, i - 1, name, &snap); + if (ret < 0) + return ret; + list_add(&snap->node, &rbd_dev->snaps); + } + + return 0; +} + + +static void rbd_root_dev_release(struct device *dev) +{ +} + +static struct device rbd_root_dev = { + .init_name = "rbd", + .release = rbd_root_dev_release, +}; + +static int rbd_bus_add_dev(struct rbd_device *rbd_dev) +{ + int ret = -ENOMEM; + struct device *dev; + struct rbd_snap *snap; + + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + dev = &rbd_dev->dev; + + dev->bus = &rbd_bus_type; + dev->type = &rbd_device_type; + dev->parent = &rbd_root_dev; + dev->release = rbd_dev_release; + dev_set_name(dev, "%d", rbd_dev->id); + ret = device_register(dev); + if (ret < 0) + goto done_free; + + list_for_each_entry(snap, &rbd_dev->snaps, node) { + ret = rbd_register_snap_dev(rbd_dev, snap, + &rbd_dev->dev); + if (ret < 0) + break; + } + + mutex_unlock(&ctl_mutex); + return 0; +done_free: + mutex_unlock(&ctl_mutex); + return ret; +} + +static void rbd_bus_del_dev(struct rbd_device *rbd_dev) +{ + device_unregister(&rbd_dev->dev); +} + +static ssize_t rbd_add(struct bus_type *bus, const char *buf, size_t count) +{ + struct ceph_osd_client *osdc; + struct rbd_device *rbd_dev; + ssize_t rc = -ENOMEM; + int irc, new_id = 0; + struct list_head *tmp; + char *mon_dev_name; + char *options; + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + mon_dev_name = kmalloc(RBD_MAX_OPT_LEN, GFP_KERNEL); + if (!mon_dev_name) + goto err_out_mod; + + options = kmalloc(RBD_MAX_OPT_LEN, GFP_KERNEL); + if (!options) + goto err_mon_dev; + + /* new rbd_device object */ + rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL); + if (!rbd_dev) + goto err_out_opt; + + /* static rbd_device initialization */ + spin_lock_init(&rbd_dev->lock); + INIT_LIST_HEAD(&rbd_dev->node); + INIT_LIST_HEAD(&rbd_dev->snaps); + + /* generate unique id: find highest unique id, add one */ + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + + list_for_each(tmp, &rbd_dev_list) { + struct rbd_device *rbd_dev; + + rbd_dev = list_entry(tmp, struct rbd_device, node); + if (rbd_dev->id >= new_id) + new_id = rbd_dev->id + 1; + } + + rbd_dev->id = new_id; + + /* add to global list */ + list_add_tail(&rbd_dev->node, &rbd_dev_list); + + /* parse add command */ + if (sscanf(buf, "%" __stringify(RBD_MAX_OPT_LEN) "s " + "%" __stringify(RBD_MAX_OPT_LEN) "s " + "%" __stringify(RBD_MAX_POOL_NAME_LEN) "s " + "%" __stringify(RBD_MAX_OBJ_NAME_LEN) "s" + "%" __stringify(RBD_MAX_SNAP_NAME_LEN) "s", + mon_dev_name, options, rbd_dev->pool_name, + rbd_dev->obj, rbd_dev->snap_name) < 4) { + rc = -EINVAL; + goto err_out_slot; + } + + if (rbd_dev->snap_name[0] == 0) + rbd_dev->snap_name[0] = '-'; + + rbd_dev->obj_len = strlen(rbd_dev->obj); + snprintf(rbd_dev->obj_md_name, sizeof(rbd_dev->obj_md_name), "%s%s", + rbd_dev->obj, RBD_SUFFIX); + + /* initialize rest of new object */ + snprintf(rbd_dev->name, DEV_NAME_LEN, DRV_NAME "%d", rbd_dev->id); + rc = rbd_get_client(rbd_dev, mon_dev_name, options); + if (rc < 0) + goto err_out_slot; + + mutex_unlock(&ctl_mutex); + + /* pick the pool */ + osdc = &rbd_dev->client->osdc; + rc = ceph_pg_poolid_by_name(osdc->osdmap, rbd_dev->pool_name); + if (rc < 0) + goto err_out_client; + rbd_dev->poolid = rc; + + /* register our block device */ + irc = register_blkdev(0, rbd_dev->name); + if (irc < 0) { + rc = irc; + goto err_out_client; + } + rbd_dev->major = irc; + + rc = rbd_bus_add_dev(rbd_dev); + if (rc) + goto err_out_blkdev; + + /* set up and announce blkdev mapping */ + rc = rbd_init_disk(rbd_dev); + if (rc) + goto err_out_bus; + + return count; + +err_out_bus: + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + list_del_init(&rbd_dev->node); + mutex_unlock(&ctl_mutex); + + /* this will also clean up rest of rbd_dev stuff */ + + rbd_bus_del_dev(rbd_dev); + kfree(options); + kfree(mon_dev_name); + return rc; + +err_out_blkdev: + unregister_blkdev(rbd_dev->major, rbd_dev->name); +err_out_client: + rbd_put_client(rbd_dev); + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); +err_out_slot: + list_del_init(&rbd_dev->node); + mutex_unlock(&ctl_mutex); + + kfree(rbd_dev); +err_out_opt: + kfree(options); +err_mon_dev: + kfree(mon_dev_name); +err_out_mod: + dout("Error adding device %s\n", buf); + module_put(THIS_MODULE); + return rc; +} + +static struct rbd_device *__rbd_get_dev(unsigned long id) +{ + struct list_head *tmp; + struct rbd_device *rbd_dev; + + list_for_each(tmp, &rbd_dev_list) { + rbd_dev = list_entry(tmp, struct rbd_device, node); + if (rbd_dev->id == id) + return rbd_dev; + } + return NULL; +} + +static void rbd_dev_release(struct device *dev) +{ + struct rbd_device *rbd_dev = + container_of(dev, struct rbd_device, dev); + + rbd_put_client(rbd_dev); + + /* clean up and free blkdev */ + rbd_free_disk(rbd_dev); + unregister_blkdev(rbd_dev->major, rbd_dev->name); + kfree(rbd_dev); + + /* release module ref */ + module_put(THIS_MODULE); +} + +static ssize_t rbd_remove(struct bus_type *bus, + const char *buf, + size_t count) +{ + struct rbd_device *rbd_dev = NULL; + int target_id, rc; + unsigned long ul; + int ret = count; + + rc = strict_strtoul(buf, 10, &ul); + if (rc) + return rc; + + /* convert to int; abort if we lost anything in the conversion */ + target_id = (int) ul; + if (target_id != ul) + return -EINVAL; + + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + + rbd_dev = __rbd_get_dev(target_id); + if (!rbd_dev) { + ret = -ENOENT; + goto done; + } + + list_del_init(&rbd_dev->node); + + __rbd_remove_all_snaps(rbd_dev); + rbd_bus_del_dev(rbd_dev); + +done: + mutex_unlock(&ctl_mutex); + return ret; +} + +static ssize_t rbd_snap_add(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + int ret; + char *name = kmalloc(count + 1, GFP_KERNEL); + if (!name) + return -ENOMEM; + + snprintf(name, count, "%s", buf); + + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + + ret = rbd_header_add_snap(rbd_dev, + name, GFP_KERNEL); + if (ret < 0) + goto done_unlock; + + ret = __rbd_update_snaps(rbd_dev); + if (ret < 0) + goto done_unlock; + + ret = count; +done_unlock: + mutex_unlock(&ctl_mutex); + kfree(name); + return ret; +} + +static ssize_t rbd_snap_rollback(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct rbd_device *rbd_dev = dev_to_rbd(dev); + int ret; + u64 snapid; + u64 cur_ofs; + char *seg_name = NULL; + char *snap_name = kmalloc(count + 1, GFP_KERNEL); + ret = -ENOMEM; + if (!snap_name) + return ret; + + /* parse snaps add command */ + snprintf(snap_name, count, "%s", buf); + seg_name = kmalloc(RBD_MAX_SEG_NAME_LEN + 1, GFP_NOIO); + if (!seg_name) + goto done; + + mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); + + ret = snap_by_name(&rbd_dev->header, snap_name, &snapid, NULL); + if (ret < 0) + goto done_unlock; + + dout("snapid=%lld\n", snapid); + + cur_ofs = 0; + while (cur_ofs < rbd_dev->header.image_size) { + cur_ofs += rbd_get_segment(&rbd_dev->header, + rbd_dev->obj, + cur_ofs, (u64)-1, + seg_name, NULL); + dout("seg_name=%s\n", seg_name); + + ret = rbd_req_sync_rollback_obj(rbd_dev, snapid, seg_name); + if (ret < 0) + pr_warning("could not roll back obj %s err=%d\n", + seg_name, ret); + } + + ret = __rbd_update_snaps(rbd_dev); + if (ret < 0) + goto done_unlock; + + ret = count; + +done_unlock: + mutex_unlock(&ctl_mutex); +done: + kfree(seg_name); + kfree(snap_name); + + return ret; +} + +static struct bus_attribute rbd_bus_attrs[] = { + __ATTR(add, S_IWUSR, NULL, rbd_add), + __ATTR(remove, S_IWUSR, NULL, rbd_remove), + __ATTR_NULL +}; + +/* + * create control files in sysfs + * /sys/bus/rbd/... + */ +static int rbd_sysfs_init(void) +{ + int ret; + + rbd_bus_type.bus_attrs = rbd_bus_attrs; + + ret = bus_register(&rbd_bus_type); + if (ret < 0) + return ret; + + ret = device_register(&rbd_root_dev); + + return ret; +} + +static void rbd_sysfs_cleanup(void) +{ + device_unregister(&rbd_root_dev); + bus_unregister(&rbd_bus_type); +} + +int __init rbd_init(void) +{ + int rc; + + rc = rbd_sysfs_init(); + if (rc) + return rc; + spin_lock_init(&node_lock); + pr_info("loaded " DRV_NAME_LONG "\n"); + return 0; +} + +void __exit rbd_exit(void) +{ + rbd_sysfs_cleanup(); +} + +module_init(rbd_init); +module_exit(rbd_exit); + +MODULE_AUTHOR("Sage Weil <sage@newdream.net>"); +MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>"); +MODULE_DESCRIPTION("rados block device"); + +/* following authorship retained from original osdblk.c */ +MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>"); + +MODULE_LICENSE("GPL"); |