3.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: Alex Elder <[email protected]> (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 <[email protected]> Reviewed-by: Dan Mick <[email protected]> Reviewed-by: Josh Durgin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/block/rbd.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) --- 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 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 r 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 r 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: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
