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Diffstat (limited to 'fs/overlayfs/Kconfig')
| -rw-r--r-- | fs/overlayfs/Kconfig | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig index 9eac01c3e21e..406e72de88f6 100644 --- a/fs/overlayfs/Kconfig +++ b/fs/overlayfs/Kconfig @@ -50,3 +50,25 @@ config OVERLAY_FS_INDEX Note, that the inodes index feature is not backward compatible. That is, mounting an overlay which has an inodes index on a kernel that doesn't support this feature will have unexpected results. + +config OVERLAY_FS_NFS_EXPORT + bool "Overlayfs: turn on NFS export feature by default" + depends on OVERLAY_FS + depends on OVERLAY_FS_INDEX + help + If this config option is enabled then overlay filesystems will use + the inodes index dir to decode overlay NFS file handles by default. + In this case, it is still possible to turn off NFS export support + globally with the "nfs_export=off" module option or on a filesystem + instance basis with the "nfs_export=off" mount option. + + The NFS export feature creates an index on copy up of every file and + directory. This full index is used to detect overlay filesystems + inconsistencies on lookup, like redirect from multiple upper dirs to + the same lower dir. The full index may incur some overhead on mount + time, especially when verifying that directory file handles are not + stale. + + Note, that the NFS export feature is not backward compatible. + That is, mounting an overlay which has a full index on a kernel + that doesn't support this feature will have unexpected results. |