[PATCH 8/8] rbd: introduce rados block device (rbd), based on libceph

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From: Sage Weil on 13 Aug 2010 13:50

---

From: Yehuda Sadeh <yehuda(a)hq.newdream.net>

The rados block device (rbd), based on osdblk, creates a block device
that is backed by objects stored in the Ceph distributed object storage
cluster. Each device consists of a single metadata object and data
striped over many data objects.

The rbd driver supports read-only snapshots.

Signed-off-by: Yehuda Sadeh <yehuda(a)hq.newdream.net>
Signed-off-by: Sage Weil <sage(a)newdream.net>
---
MAINTAINERS | 9 +
drivers/block/Kconfig | 13 +
drivers/block/Makefile | 1 +
drivers/block/rbd.c | 1844 +++++++++++++++++++++++++++++++++++++++++++++
drivers/block/rbd_types.h | 73 ++
5 files changed, 1940 insertions(+), 0 deletions(-)
create mode 100644 drivers/block/rbd.c
create mode 100644 drivers/block/rbd_types.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 5102922..cb34b1b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4694,6 +4694,15 @@ F: fs/qnx4/
F: include/linux/qnx4_fs.h
F: include/linux/qnxtypes.h

+RADOS BLOCK DEVICE (RBD)
+F: include/linux/qnxtypes.h
+M: Yehuda Sadeh <yehuda(a)hq.newdream.net>
+M: Sage Weil <sage(a)newdream.net>
+M: ceph-devel(a)vger.kernel.org
+S: Supported
+F: drivers/block/rbd.c
+F: drivers/block/rbd_types.h
+
RADEON FRAMEBUFFER DISPLAY DRIVER
M: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
L: linux-fbdev(a)vger.kernel.org
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index de27768..708104b 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -488,4 +488,17 @@ config BLK_DEV_HD

If unsure, say N.

+config BLK_DEV_RBD
+ tristate "Rados block device (RBD)"
+ select CEPH_LIB
+ default n
+ help
+ Say Y here if you want include the Rados block device, which stripes
+ a block device over objects stored in the Ceph distributed object
+ store.
+
+ More information at http://ceph.newdream.net/.
+
+ If unsure, say N.
+
endif # BLK_DEV
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index aff5ac9..d7f463d 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -37,5 +37,6 @@ obj-$(CONFIG_BLK_DEV_HD) += hd.o

obj-$(CONFIG_XEN_BLKDEV_FRONTEND) += xen-blkfront.o
obj-$(CONFIG_BLK_DEV_DRBD) += drbd/
+obj-$(CONFIG_BLK_DEV_RBD) += rbd.o

swim_mod-objs := swim.o swim_asm.o
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
new file mode 100644
index 0000000..f4cd870
--- /dev/null
+++ b/drivers/block/rbd.c
@@ -0,0 +1,1844 @@
+/*
+ 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.
+
+
+
+ Instructions for use
+ --------------------
+
+ 1) Map a Linux block device to an existing rbd image.
+
+ Usage: <mon ip addr> <options> <pool name> <rbd image name> [snap name]
+
+ $ echo "192.168.0.1 name=admin rbd foo" > /sys/class/rbd/add
+
+ The snapshot name can be "-" or omitted to map the image read/write.
+
+ 2) List all active blkdev<->object mappings.
+
+ In this example, we have performed step #1 twice, creating two blkdevs,
+ mapped to two separate rados objects in the rados rbd pool
+
+ $ cat /sys/class/rbd/list
+ #id major client_name pool name snap KB
+ 0 254 client4143 rbd foo - 1024000
+
+ The columns, in order, are:
+ - blkdev unique id
+ - blkdev assigned major
+ - rados client id
+ - rados pool name
+ - rados block device name
+ - mapped snapshot ("-" if none)
+ - device size in KB
+
+
+ 3) Create a snapshot.
+
+ Usage: <blkdev id> <snapname>
+
+ $ echo "0 mysnap" > /sys/class/rbd/snap_create
+
+
+ 4) Listing a snapshot.
+
+ $ cat /sys/class/rbd/snaps_list
+ #id snap KB
+ 0 - 1024000 (*)
+ 0 foo 1024000
+
+ The columns, in order, are:
+ - blkdev unique id
+ - snapshot name, '-' means none (active read/write version)
+ - size of device at time of snapshot
+ - the (*) indicates this is the active version
+
+ 5) Rollback to snapshot.
+
+ Usage: <blkdev id> <snapname>
+
+ $ echo "0 mysnap" > /sys/class/rbd/snap_rollback
+
+
+ 6) Mapping an image using snapshot.
+
+ A snapshot mapping is read-only. This is being done by passing
+ snap=<snapname> to the options when adding a device.
+
+ $ echo "192.168.0.1 name=admin,snap=mysnap rbd foo" > /sys/class/rbd/add
+
+
+ 7) Remove an active blkdev<->rbd image mapping.
+
+ In this example, we remove the mapping with blkdev unique id 1.
+
+ $ echo 1 > /sys/class/rbd/remove
+
+
+ NOTE: The actual creation and deletion of rados objects is outside the scope
+ of this driver.
+
+ */
+
+#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;
+};
+
+/*
+ * 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;
+};
+
+static spinlock_t node_lock; /* protects client get/put */
+
+static struct class *class_rbd; /* /sys/class/rbd */
+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_open(struct block_device *bdev, fmode_t mode)
+{
+ struct gendisk *disk = bdev->bd_disk;
+ struct rbd_device *rbd_dev = disk->private_data;
+
+ set_device_ro(bdev, rbd_dev->read_only);
+
+ if ((mode & FMODE_WRITE) && rbd_dev->read_only)
+ return -EROFS;
+
+ return 0;
+}
+
+static const struct block_device_operations rbd_bd_ops = {
+ .owner = THIS_MODULE,
+ .open = rbd_open,
+};
+
+/*
+ * Initialize an rbd client instance.
+ */
+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;
+
+ kref_init(&rbdc->kref);
+ INIT_LIST_HEAD(&rbdc->node);
+
+ rbdc->client = ceph_create_client(opt, rbdc);
+ if (IS_ERR(rbdc->client))
+ goto out_free;
+
+ 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_free:
+ kfree(rbdc);
+out:
+ return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * 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)) {
+ ret = PTR_ERR(rbdc);
+ goto out_args;
+ }
+ rbd_dev->rbd_client = rbdc;
+ rbd_dev->client = rbdc->client;
+ return 0;
+
+out_args:
+ ceph_destroy_options(opt);
+ return ret;
+}
+
+/*
+ * 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(bv, &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 (!pages)
+ return -ENOMEM;
+
+ 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);
+ if (seg_len < 0)
+ return seg_len;
+
+ 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;
+}
+
+/*
+ * 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_sizes = h.snap_sizes;
+ rbd_dev->header.snapc->seq = snap_seq;
+
+ up_write(&rbd_dev->header.snap_rwsem);
+
+ return 0;
+}
+
+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;
+
+ 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;
+}
+
+/********************************************************************
+ * /sys/class/rbd/
+ * add map rados objects to blkdev
+ * remove unmap rados objects
+ * list show mappings
+ *******************************************************************/
+
+static void class_rbd_release(struct class *cls)
+{
+ kfree(cls);
+}
+
+static ssize_t class_rbd_list(struct class *c,
+ struct class_attribute *attr,
+ char *data)
+{
+ int n = 0;
+ struct list_head *tmp;
+ int max = PAGE_SIZE;
+
+ mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
+ n += snprintf(data, max,
+ "#id\tmajor\tclient_name\tpool\tname\tsnap\tKB\n");
+
+ list_for_each(tmp, &rbd_dev_list) {
+ struct rbd_device *rbd_dev;
+
+ rbd_dev = list_entry(tmp, struct rbd_device, node);
+ n += snprintf(data+n, max-n,
+ "%d\t%d\tclient%lld\t%s\t%s\t%s\t%lld\n",
+ rbd_dev->id,
+ rbd_dev->major,
+ ceph_client_id(rbd_dev->client),
+ rbd_dev->pool_name,
+ rbd_dev->obj, rbd_dev->snap_name,
+ rbd_dev->header.image_size >> 10);
+ if (n == max)
+ break;
+ }
+
+ mutex_unlock(&ctl_mutex);
+ return n;
+}
+
+static ssize_t class_rbd_add(struct class *c,
+ struct class_attribute *attr,
+ 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);
+
+ /* 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;
+
+ /* set up and announce blkdev mapping */
+ rc = rbd_init_disk(rbd_dev);
+ if (rc)
+ goto err_out_blkdev;
+
+ return count;
+
+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 ssize_t class_rbd_remove(struct class *c,
+ struct class_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct rbd_device *rbd_dev = NULL;
+ int target_id, rc;
+ unsigned long ul;
+
+ 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;
+
+ /* remove object from list immediately */
+ mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
+ rbd_dev = __rbd_get_dev(target_id);
+ if (rbd_dev)
+ list_del_init(&rbd_dev->node);
+
+ mutex_unlock(&ctl_mutex);
+
+ if (!rbd_dev)
+ return -ENOENT;
+
+ 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);
+
+ return count;
+}
+
+static ssize_t class_rbd_snaps_list(struct class *c,
+ struct class_attribute *attr,
+ char *data)
+{
+ struct rbd_device *rbd_dev = NULL;
+ struct list_head *tmp;
+ struct rbd_image_header *header;
+ int i, n = 0, max = PAGE_SIZE;
+ int ret;
+
+ mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
+ n += snprintf(data, max, "#id\tsnap\tKB\n");
+
+ list_for_each(tmp, &rbd_dev_list) {
+ char *names, *p;
+ struct ceph_snap_context *snapc;
+
+ rbd_dev = list_entry(tmp, struct rbd_device, node);
+ header = &rbd_dev->header;
+
+ down_read(&header->snap_rwsem);
+
+ names = header->snap_names;
+ snapc = header->snapc;
+
+ n += snprintf(data + n, max - n, "%d\t%s\t%lld%s\n",
+ rbd_dev->id, RBD_SNAP_HEAD_NAME,
+ header->image_size >> 10,
+ (!rbd_dev->cur_snap ? " (*)" : ""));
+ if (n == max)
+ break;
+
+ p = names;
+ for (i = 0; i < header->total_snaps; i++, p += strlen(p) + 1) {
+ n += snprintf(data + n, max - n, "%d\t%s\t%lld%s\n",
+ rbd_dev->id, p, header->snap_sizes[i] >> 10,
+ (rbd_dev->cur_snap &&
+ (snap_index(header, i) == rbd_dev->cur_snap) ?
+ " (*)" : ""));
+ if (n == max)
+ break;
+ }
+
+ up_read(&header->snap_rwsem);
+ }
+
+
+ ret = n;
+ mutex_unlock(&ctl_mutex);
+ return ret;
+}
+
+static ssize_t class_rbd_snaps_refresh(struct class *c,
+ struct class_attribute *attr,
+ 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;
+ }
+
+ rc = rbd_update_snaps(rbd_dev);
+ if (rc < 0)
+ ret = rc;
+
+done:
+ mutex_unlock(&ctl_mutex);
+ return ret;
+}
+
+static ssize_t class_rbd_snap_create(struct class *c,
+ struct class_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct rbd_device *rbd_dev = NULL;
+ int target_id, ret;
+ char *name;
+
+ name = kmalloc(RBD_MAX_SNAP_NAME_LEN + 1, GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+
+ /* parse snaps add command */
+ if (sscanf(buf, "%d "
+ "%" __stringify(RBD_MAX_SNAP_NAME_LEN) "s",
+ &target_id,
+ name) != 2) {
+ ret = -EINVAL;
+ goto done;
+ }
+
+ mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
+ rbd_dev = __rbd_get_dev(target_id);
+ if (!rbd_dev) {
+ ret = -ENOENT;
+ goto done_unlock;
+ }
+
+ 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);
+done:
+ kfree(name);
+ return ret;
+}
+
+static ssize_t class_rbd_rollback(struct class *c,
+ struct class_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct rbd_device *rbd_dev = NULL;
+ int target_id, ret;
+ u64 snapid;
+ char snap_name[RBD_MAX_SNAP_NAME_LEN];
+ u64 cur_ofs;
+ char *seg_name;
+
+ /* parse snaps add command */
+ if (sscanf(buf, "%d "
+ "%" __stringify(RBD_MAX_SNAP_NAME_LEN) "s",
+ &target_id,
+ snap_name) != 2) {
+ return -EINVAL;
+ }
+
+ ret = -ENOMEM;
+ seg_name = kmalloc(RBD_MAX_SEG_NAME_LEN + 1, GFP_NOIO);
+ if (!seg_name)
+ return ret;
+
+ mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
+ rbd_dev = __rbd_get_dev(target_id);
+ if (!rbd_dev) {
+ ret = -ENOENT;
+ goto done_unlock;
+ }
+
+ 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);
+ kfree(seg_name);
+
+ return ret;
+}
+
+static struct class_attribute class_rbd_attrs[] = {
+ __ATTR(add, 0200, NULL, class_rbd_add),
+ __ATTR(remove, 0200, NULL, class_rbd_remove),
+ __ATTR(list, 0444, class_rbd_list, NULL),
+ __ATTR(snaps_refresh, 0200, NULL, class_rbd_snaps_refresh),
+ __ATTR(snap_create, 0200, NULL, class_rbd_snap_create),
+ __ATTR(snaps_list, 0444, class_rbd_snaps_list, NULL),
+ __ATTR(snap_rollback, 0200, NULL, class_rbd_rollback),
+ __ATTR_NULL
+};
+
+/*
+ * create control files in sysfs
+ * /sys/class/rbd/...
+ */
+static int rbd_sysfs_init(void)
+{
+ int ret = -ENOMEM;
+
+ class_rbd = kzalloc(sizeof(*class_rbd), GFP_KERNEL);
+ if (!class_rbd)
+ goto out;
+
+ class_rbd->name = DRV_NAME;
+ class_rbd->owner = THIS_MODULE;
+ class_rbd->class_release = class_rbd_release;
+ class_rbd->class_attrs = class_rbd_attrs;
+
+ ret = class_register(class_rbd);
+ if (ret)
+ goto out_class;
+ return 0;
+
+out_class:
+ kfree(class_rbd);
+ class_rbd = NULL;
+ pr_err(DRV_NAME ": failed to create class rbd\n");
+out:
+ return ret;
+}
+
+static void rbd_sysfs_cleanup(void)
+{
+ if (class_rbd)
+ class_destroy(class_rbd);
+ class_rbd = NULL;
+}
+
+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(a)newdream.net>");
+MODULE_AUTHOR("Yehuda Sadeh <yehuda(a)hq.newdream.net>");
+MODULE_DESCRIPTION("rados block device");
+
+/* following authorship retained from original osdblk.c */
+MODULE_AUTHOR("Jeff Garzik <jeff(a)garzik.org>");
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/block/rbd_types.h b/drivers/block/rbd_types.h
new file mode 100644
index 0000000..fc6c678
--- /dev/null
+++ b/drivers/block/rbd_types.h
@@ -0,0 +1,73 @@
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2010 Sage Weil <sage(a)newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#ifndef CEPH_RBD_TYPES_H
+#define CEPH_RBD_TYPES_H
+
+#include <linux/types.h>
+
+/*
+ * rbd image 'foo' consists of objects
+ * foo.rbd - image metadata
+ * foo.00000000
+ * foo.00000001
+ * ... - data
+ */
+
+#define RBD_SUFFIX ".rbd"
+#define RBD_DIRECTORY "rbd_directory"
+#define RBD_INFO "rbd_info"
+
+#define RBD_DEFAULT_OBJ_ORDER 22 /* 4MB */
+#define RBD_MIN_OBJ_ORDER 16
+#define RBD_MAX_OBJ_ORDER 30
+
+#define RBD_MAX_OBJ_NAME_LEN 96
+#define RBD_MAX_SEG_NAME_LEN 128
+
+#define RBD_COMP_NONE 0
+#define RBD_CRYPT_NONE 0
+
+#define RBD_HEADER_TEXT "<<< Rados Block Device Image >>>\n"
+#define RBD_HEADER_SIGNATURE "RBD"
+#define RBD_HEADER_VERSION "001.005"
+
+struct rbd_info {
+ __le64 max_id;
+} __attribute__ ((packed));
+
+struct rbd_image_snap_ondisk {
+ __le64 id;
+ __le64 image_size;
+} __attribute__((packed));
+
+struct rbd_image_header_ondisk {
+ char text[40];
+ char block_name[24];
+ char signature[4];
+ char version[8];
+ struct {
+ __u8 order;
+ __u8 crypt_type;
+ __u8 comp_type;
+ __u8 unused;
+ } __attribute__((packed)) options;
+ __le64 image_size;
+ __le64 snap_seq;
+ __le32 snap_count;
+ __le32 reserved;
+ __le64 snap_names_len;
+ struct rbd_image_snap_ondisk snaps[0];
+} __attribute__((packed));
+
+
+#endif
--
1.7.0

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