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authorAlex Elder <elder@inktank.com>2012-07-03 16:01:19 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-17 08:46:49 -0800
commitfefc034ae0af85c0b18fe209a1b6803d51880556 (patch)
tree34c6c986f149c8993dac84debc476d2a078fcc08
parentd741dc0695e62bcd1b7cfc7a8baa1f9e95fd07c7 (diff)
rbd: increase maximum snapshot name length
(cherry picked from commit d4b125e9eb43babd14538ba61718e3db71a98d29) Change RBD_MAX_SNAP_NAME_LEN to be based on NAME_MAX. That is a practical limit for the length of a snapshot name (based on the presence of a directory using the name under /sys/bus/rbd to represent the snapshot). The /sys entry is created by prefixing it with "snap_"; define that prefix symbolically, and take its length into account in defining the snapshot name length limit. Enforce the limit in rbd_add_parse_args(). Also delete a dout() call in that function that was not meant to be committed. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Dan Mick <dan.mick@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/block/rbd.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index b5e5ffec9c05..cd75b4d38e27 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -61,7 +61,10 @@
#define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
-#define RBD_MAX_SNAP_NAME_LEN 32
+#define RBD_SNAP_DEV_NAME_PREFIX "snap_"
+#define RBD_MAX_SNAP_NAME_LEN \
+ (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
+
#define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
#define RBD_MAX_OPT_LEN 1024
@@ -2073,7 +2076,7 @@ static int rbd_register_snap_dev(struct rbd_snap *snap,
dev->type = &rbd_snap_device_type;
dev->parent = parent;
dev->release = rbd_snap_dev_release;
- dev_set_name(dev, "snap_%s", snap->name);
+ dev_set_name(dev, "%s%s", RBD_SNAP_DEV_NAME_PREFIX, snap->name);
dout("%s: registering device for snapshot %s\n", __func__, snap->name);
ret = device_register(dev);
@@ -2766,8 +2769,13 @@ static char *rbd_add_parse_args(struct rbd_device *rbd_dev,
if (!rbd_dev->image_name)
goto out_err;
- /* Snapshot name is optional */
+ /* Snapshot name is optional; default is to use "head" */
+
len = next_token(&buf);
+ if (len > RBD_MAX_SNAP_NAME_LEN) {
+ err_ptr = ERR_PTR(-ENAMETOOLONG);
+ goto out_err;
+ }
if (!len) {
buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
@@ -2778,8 +2786,6 @@ static char *rbd_add_parse_args(struct rbd_device *rbd_dev,
memcpy(snap_name, buf, len);
*(snap_name + len) = '\0';
-dout(" SNAP_NAME is <%s>, len is %zd\n", snap_name, len);
-
return snap_name;
out_err: