rbd: separate mapping info in rbd_dev
Several fields in a struct rbd_dev are related to what is mapped, as opposed to the actual base rbd image. If the base image is mapped these are almost unneeded, but if a snapshot is mapped they describe information about that snapshot. In some contexts this can be a little bit confusing. So group these mapping-related field into a structure to make it clear what they are describing. This also includes a minor change that rearranges the fields in the in-core image header structure so that invariant fields are at the top, followed by those that change. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder
Родитель
c9aadfe786
Коммит
f84344f334
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@ -81,13 +81,15 @@
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* block device image metadata (in-memory version)
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*/
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struct rbd_image_header {
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u64 image_size;
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/* These four fields never change for a given rbd image */
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char *object_prefix;
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__u8 obj_order;
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__u8 crypt_type;
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__u8 comp_type;
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struct ceph_snap_context *snapc;
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/* The remaining fields need to be updated occasionally */
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u64 image_size;
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struct ceph_snap_context *snapc;
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char *snap_names;
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u64 *snap_sizes;
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@ -146,6 +148,13 @@ struct rbd_snap {
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u64 id;
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};
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struct rbd_mapping {
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char *snap_name;
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u64 snap_id;
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bool snap_exists;
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bool read_only;
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};
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/*
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* a single device
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*/
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@ -174,13 +183,8 @@ struct rbd_device {
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/* protects updating the header */
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struct rw_semaphore header_rwsem;
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/* name of the snapshot this device reads from */
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char *snap_name;
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/* id of the snapshot this device reads from */
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u64 snap_id; /* current snapshot id */
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/* whether the snap_id this device reads from still exists */
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bool snap_exists;
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bool read_only;
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struct rbd_mapping mapping;
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struct list_head node;
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@ -261,11 +265,11 @@ static int rbd_open(struct block_device *bdev, fmode_t mode)
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{
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struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
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if ((mode & FMODE_WRITE) && rbd_dev->read_only)
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if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
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return -EROFS;
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rbd_get_dev(rbd_dev);
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set_device_ro(bdev, rbd_dev->read_only);
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set_device_ro(bdev, rbd_dev->mapping.read_only);
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return 0;
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}
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@ -375,7 +379,7 @@ enum {
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static match_table_t rbd_opts_tokens = {
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/* int args above */
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/* string args above */
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{Opt_read_only, "read_only"},
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{Opt_read_only, "mapping.read_only"},
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{Opt_read_only, "ro"}, /* Alternate spelling */
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{Opt_read_write, "read_write"},
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{Opt_read_write, "rw"}, /* Alternate spelling */
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@ -583,13 +587,13 @@ static int rbd_header_from_disk(struct rbd_image_header *header,
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header->snap_sizes = NULL;
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}
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header->image_size = le64_to_cpu(ondisk->image_size);
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header->obj_order = ondisk->options.order;
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header->crypt_type = ondisk->options.crypt_type;
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header->comp_type = ondisk->options.comp_type;
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/* Allocate and fill in the snapshot context */
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header->image_size = le64_to_cpu(ondisk->image_size);
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size = sizeof (struct ceph_snap_context);
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size += snap_count * sizeof (header->snapc->snaps[0]);
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header->snapc = kzalloc(size, GFP_KERNEL);
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@ -645,23 +649,24 @@ static int rbd_header_set_snap(struct rbd_device *rbd_dev, u64 *size)
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down_write(&rbd_dev->header_rwsem);
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if (!memcmp(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME,
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if (!memcmp(rbd_dev->mapping.snap_name, RBD_SNAP_HEAD_NAME,
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sizeof (RBD_SNAP_HEAD_NAME))) {
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rbd_dev->snap_id = CEPH_NOSNAP;
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rbd_dev->snap_exists = false;
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rbd_dev->read_only = rbd_dev->rbd_opts.read_only;
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rbd_dev->mapping.snap_id = CEPH_NOSNAP;
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rbd_dev->mapping.snap_exists = false;
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rbd_dev->mapping.read_only = rbd_dev->rbd_opts.read_only;
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if (size)
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*size = rbd_dev->header.image_size;
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} else {
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u64 snap_id = 0;
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ret = snap_by_name(&rbd_dev->header, rbd_dev->snap_name,
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ret = snap_by_name(&rbd_dev->header,
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rbd_dev->mapping.snap_name,
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&snap_id, size);
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if (ret < 0)
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goto done;
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rbd_dev->snap_id = snap_id;
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rbd_dev->snap_exists = true;
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rbd_dev->read_only = true; /* No choice for snapshots */
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rbd_dev->mapping.snap_id = snap_id;
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rbd_dev->mapping.snap_exists = true;
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rbd_dev->mapping.read_only = true;
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}
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ret = 0;
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@ -1532,7 +1537,7 @@ static void rbd_rq_fn(struct request_queue *q)
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size = blk_rq_bytes(rq);
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ofs = blk_rq_pos(rq) * SECTOR_SIZE;
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rq_bio = rq->bio;
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if (do_write && rbd_dev->read_only) {
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if (do_write && rbd_dev->mapping.read_only) {
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__blk_end_request_all(rq, -EROFS);
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continue;
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}
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@ -1541,7 +1546,8 @@ static void rbd_rq_fn(struct request_queue *q)
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down_read(&rbd_dev->header_rwsem);
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if (rbd_dev->snap_id != CEPH_NOSNAP && !rbd_dev->snap_exists) {
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if (rbd_dev->mapping.snap_id != CEPH_NOSNAP &&
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!rbd_dev->mapping.snap_exists) {
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up_read(&rbd_dev->header_rwsem);
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dout("request for non-existent snapshot");
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spin_lock_irq(q->queue_lock);
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@ -1595,7 +1601,7 @@ static void rbd_rq_fn(struct request_queue *q)
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coll, cur_seg);
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else
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rbd_req_read(rq, rbd_dev,
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rbd_dev->snap_id,
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rbd_dev->mapping.snap_id,
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ofs,
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op_size, bio,
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coll, cur_seg);
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@ -1767,7 +1773,7 @@ static int rbd_header_add_snap(struct rbd_device *rbd_dev,
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struct ceph_mon_client *monc;
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/* we should create a snapshot only if we're pointing at the head */
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if (rbd_dev->snap_id != CEPH_NOSNAP)
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if (rbd_dev->mapping.snap_id != CEPH_NOSNAP)
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return -EINVAL;
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monc = &rbd_dev->rbd_client->client->monc;
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@ -1821,7 +1827,7 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
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down_write(&rbd_dev->header_rwsem);
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/* resized? */
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if (rbd_dev->snap_id == CEPH_NOSNAP) {
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if (rbd_dev->mapping.snap_id == CEPH_NOSNAP) {
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sector_t size = (sector_t) h.image_size / SECTOR_SIZE;
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dout("setting size to %llu sectors", (unsigned long long) size);
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@ -2004,7 +2010,7 @@ static ssize_t rbd_snap_show(struct device *dev,
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{
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struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
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return sprintf(buf, "%s\n", rbd_dev->snap_name);
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return sprintf(buf, "%s\n", rbd_dev->mapping.snap_name);
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}
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static ssize_t rbd_image_refresh(struct device *dev,
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@ -2205,11 +2211,12 @@ static int rbd_dev_snap_devs_update(struct rbd_device *rbd_dev)
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/* Existing snapshot not in the new snap context */
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if (rbd_dev->snap_id == snap->id)
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rbd_dev->snap_exists = false;
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if (rbd_dev->mapping.snap_id == snap->id)
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rbd_dev->mapping.snap_exists = false;
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__rbd_remove_snap_dev(snap);
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dout("%ssnap id %llu has been removed\n",
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rbd_dev->snap_id == snap->id ? "mapped " : "",
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rbd_dev->mapping.snap_id == snap->id ?
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"mapped " : "",
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(unsigned long long) snap->id);
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/* Done with this list entry; advance */
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@ -2522,18 +2529,18 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev,
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* The snapshot name is optional. If none is is supplied,
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* we use the default value.
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*/
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rbd_dev->snap_name = dup_token(&buf, &len);
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if (!rbd_dev->snap_name)
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rbd_dev->mapping.snap_name = dup_token(&buf, &len);
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if (!rbd_dev->mapping.snap_name)
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goto out_err;
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if (!len) {
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/* Replace the empty name with the default */
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kfree(rbd_dev->snap_name);
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rbd_dev->snap_name
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kfree(rbd_dev->mapping.snap_name);
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rbd_dev->mapping.snap_name
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= kmalloc(sizeof (RBD_SNAP_HEAD_NAME), GFP_KERNEL);
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if (!rbd_dev->snap_name)
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if (!rbd_dev->mapping.snap_name)
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goto out_err;
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memcpy(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME,
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memcpy(rbd_dev->mapping.snap_name, RBD_SNAP_HEAD_NAME,
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sizeof (RBD_SNAP_HEAD_NAME));
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}
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@ -2642,7 +2649,7 @@ err_out_client:
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rbd_put_client(rbd_dev);
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err_put_id:
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if (rbd_dev->pool_name) {
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kfree(rbd_dev->snap_name);
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kfree(rbd_dev->mapping.snap_name);
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kfree(rbd_dev->header_name);
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kfree(rbd_dev->image_name);
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kfree(rbd_dev->pool_name);
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@ -2695,7 +2702,7 @@ static void rbd_dev_release(struct device *dev)
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unregister_blkdev(rbd_dev->major, rbd_dev->name);
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/* done with the id, and with the rbd_dev */
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kfree(rbd_dev->snap_name);
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kfree(rbd_dev->mapping.snap_name);
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kfree(rbd_dev->header_name);
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kfree(rbd_dev->pool_name);
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kfree(rbd_dev->image_name);
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