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 <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2012-07-09 21:04:24 -05:00 committed by Sage Weil
parent bf3e5ae112
commit 820a5f3e94

View File

@ -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);