diff options
Diffstat (limited to 'Documentation/filesystems/overlayfs.rst')
| -rw-r--r-- | Documentation/filesystems/overlayfs.rst | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index 8275ed735f77..35853906accb 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -664,7 +664,7 @@ UUID and fsid The UUID of overlayfs instance itself and the fsid reported by statfs(2) are controlled by the "uuid" mount option, which supports these values: -- "null": (default) +- "null": UUID of overlayfs is null. fsid is taken from upper most filesystem. - "off": UUID of overlayfs is null. fsid is taken from upper most filesystem. @@ -674,6 +674,12 @@ controlled by the "uuid" mount option, which supports these values: UUID is stored in xattr "trusted.overlay.uuid", making overlayfs fsid unique and persistent. This option requires an overlayfs with upper filesystem that supports xattrs. +- "auto": (default) + UUID is taken from xattr "trusted.overlay.uuid" if it exists. + Upgrade to "uuid=on" on first time mount of new overlay filesystem that + meets the prerequites. + Downgrade to "uuid=null" for existing overlay filesystems that were never + mounted with "uuid=on". Volatile mount |