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| author | Amir Goldstein <amir73il@gmail.com> | 2023-07-07 11:20:41 +0300 |
|---|---|---|
| committer | Amir Goldstein <amir73il@gmail.com> | 2023-08-12 19:02:50 +0300 |
| commit | d9544c1b0d9e14a66936814dcc8a85861ea1b99f (patch) | |
| tree | b8c8a2f1daee13141cd107888e932902873569d4 /Documentation/filesystems | |
| parent | b0504bfe1b8acdcfb5ef466581d930835ef3c49e (diff) | |
| download | linux-d9544c1b0d9e14a66936814dcc8a85861ea1b99f.tar.gz | |
ovl: store persistent uuid/fsid with uuid=on
With uuid=on, store a persistent uuid in xattr on the upper dir to
give the overlayfs instance a persistent identifier.
This also makes f_fsid persistent and more reliable for reporting
fid info in fanotify events.
uuid=on is not supported on non-upper overlayfs or with upper fs
that does not support xattrs.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/overlayfs.rst | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index d55381d3fa0f4..8275ed735f774 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -671,6 +671,9 @@ controlled by the "uuid" mount option, which supports these values: UUID of underlying layers is ignored. - "on": UUID of overlayfs is generated and used to report a unique fsid. + 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. Volatile mount |