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| author | Vivek Goyal <vgoyal@redhat.com> | 2018-05-11 17:49:27 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-07-20 09:56:06 +0200 |
| commit | d5791044d2e5749ef4de84161cec5532e2111540 (patch) | |
| tree | 3abb05f2e56381c9d591b8f74bc838836ef4f6fd /fs/overlayfs/Kconfig | |
| parent | ovl: Move the copy up helpers to copy_up.c (diff) | |
| download | linux-d5791044d2e5749ef4de84161cec5532e2111540.tar.xz linux-d5791044d2e5749ef4de84161cec5532e2111540.zip | |
ovl: Provide a mount option metacopy=on/off for metadata copyup
By default metadata only copy up is disabled. Provide a mount option so
that users can choose one way or other.
Also provide a kernel config and module option to enable/disable metacopy
feature.
metacopy feature requires redirect_dir=on when upper is present.
Otherwise, it requires redirect_dir=follow atleast.
As of now, metacopy does not work with nfs_export=on. So if both
metacopy=on and nfs_export=on then nfs_export is disabled.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/Kconfig')
| -rw-r--r-- | fs/overlayfs/Kconfig | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig index 9384164253ac..2ef91be2a04e 100644 --- a/fs/overlayfs/Kconfig +++ b/fs/overlayfs/Kconfig @@ -64,6 +64,7 @@ config OVERLAY_FS_NFS_EXPORT bool "Overlayfs: turn on NFS export feature by default" depends on OVERLAY_FS depends on OVERLAY_FS_INDEX + depends on !OVERLAY_FS_METACOPY help If this config option is enabled then overlay filesystems will use the index directory to decode overlay NFS file handles by default. @@ -103,3 +104,21 @@ config OVERLAY_FS_XINO_AUTO For more information, see Documentation/filesystems/overlayfs.txt If unsure, say N. + +config OVERLAY_FS_METACOPY + bool "Overlayfs: turn on metadata only copy up feature by default" + depends on OVERLAY_FS + select OVERLAY_FS_REDIRECT_DIR + help + If this config option is enabled then overlay filesystems will + copy up only metadata where appropriate and data copy up will + happen when a file is opened for WRITE operation. It is still + possible to turn off this feature globally with the "metacopy=off" + module option or on a filesystem instance basis with the + "metacopy=off" mount option. + + Note, that this feature is not backward compatible. That is, + mounting an overlay which has metacopy only inodes on a kernel + that doesn't support this feature will have unexpected results. + + If unsure, say N. |