From 820a5f3e94b9f8ea8c0c6125ce34b237ed67b1dc Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 9 Jul 2012 21:04:24 -0500 Subject: [PATCH] rbd: dynamically allocate snapshot name There is no need to impose a small limit the length of the snapshot name recorded for an rbd image in a struct rbd_dev. Remove the limitation by allocating space for the snapshot name dynamically. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 7d4735c9dba5..5c0f0445982c 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -172,7 +172,7 @@ struct rbd_device { /* protects updating the header */ struct rw_semaphore header_rwsem; - char snap_name[RBD_MAX_SNAP_NAME_LEN]; + char *snap_name; u64 snap_id; /* current snapshot id */ int read_only; @@ -588,8 +588,6 @@ static int rbd_header_set_snap(struct rbd_device *dev, u64 *size) struct ceph_snap_context *snapc = header->snapc; int ret = -ENOENT; - BUILD_BUG_ON(sizeof (dev->snap_name) < sizeof (RBD_SNAP_HEAD_NAME)); - down_write(&dev->header_rwsem); if (!memcmp(dev->snap_name, RBD_SNAP_HEAD_NAME, @@ -2390,16 +2388,22 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev, sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX); /* - * The snapshot name is optional, but it's an error if it's - * too long. If no snapshot is supplied, fill in the default. + * The snapshot name is optional. If none is is supplied, + * we use the default value. */ - len = copy_token(&buf, rbd_dev->snap_name, sizeof (rbd_dev->snap_name)); - if (!len) + rbd_dev->snap_name = dup_token(&buf, &len); + if (!rbd_dev->snap_name) + goto out_err; + if (!len) { + /* Replace the empty name with the default */ + kfree(rbd_dev->snap_name); + rbd_dev->snap_name + = kmalloc(sizeof (RBD_SNAP_HEAD_NAME), GFP_KERNEL); + if (!rbd_dev->snap_name) + goto out_err; + memcpy(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME, sizeof (RBD_SNAP_HEAD_NAME)); - else if (len >= sizeof (rbd_dev->snap_name)) { - ret = -EINVAL; - goto out_err; } return 0; @@ -2509,6 +2513,7 @@ err_out_client: rbd_put_client(rbd_dev); err_put_id: if (rbd_dev->pool_name) { + kfree(rbd_dev->snap_name); kfree(rbd_dev->obj_md_name); kfree(rbd_dev->obj); kfree(rbd_dev->pool_name); @@ -2561,6 +2566,7 @@ static void rbd_dev_release(struct device *dev) unregister_blkdev(rbd_dev->major, rbd_dev->name); /* done with the id, and with the rbd_dev */ + kfree(rbd_dev->snap_name); kfree(rbd_dev->obj_md_name); kfree(rbd_dev->pool_name); kfree(rbd_dev->obj); -- 2.20.1