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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2020-09-10 19:57:17 +0200 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2020-09-16 05:52:43 +0200 |
| commit | b96cb835e37c2ca03aaceef9555ec9047a422d91 (patch) | |
| tree | 7f686890071d175b91ad07346ef4df85de9a0494 /Documentation/admin-guide/xfs.rst | |
| parent | xfs: don't propagate RTINHERIT -> REALTIME when there is no rtdev (diff) | |
| download | linux-b96cb835e37c2ca03aaceef9555ec9047a422d91.tar.xz linux-b96cb835e37c2ca03aaceef9555ec9047a422d91.zip | |
xfs: deprecate the V4 format
The V4 filesystem format contains known weaknesses in the on-disk format
that make metadata verification diffiult. In addition, the format does
not support dates past 2038 and will not be upgraded to do so. We
should start the process of retiring the old format to close off attack
surfaces and to encourage users to migrate onto V5.
Therefore, make XFS V4 support a configurable option. For the first
period it will be default Y in case some distributors want to withdraw
support early; for the second period it will be default N so that anyone
who wishes to continue support can do so; and after that, support will
be removed from the kernel. Dates for these events have been added to
the upstream kernel.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Diffstat (limited to 'Documentation/admin-guide/xfs.rst')
| -rw-r--r-- | Documentation/admin-guide/xfs.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/admin-guide/xfs.rst b/Documentation/admin-guide/xfs.rst index f461d6c33534..a0e271dcaf82 100644 --- a/Documentation/admin-guide/xfs.rst +++ b/Documentation/admin-guide/xfs.rst @@ -210,6 +210,28 @@ When mounting an XFS filesystem, the following options are accepted. inconsistent namespace presentation during or after a failover event. +Deprecation of V4 Format +======================== + +The V4 filesystem format lacks certain features that are supported by +the V5 format, such as metadata checksumming, strengthened metadata +verification, and the ability to store timestamps past the year 2038. +Because of this, the V4 format is deprecated. All users should upgrade +by backing up their files, reformatting, and restoring from the backup. + +Administrators and users can detect a V4 filesystem by running xfs_info +against a filesystem mountpoint and checking for a string containing +"crc=". If no such string is found, please upgrade xfsprogs to the +latest version and try again. + +The deprecation will take place in two parts. Support for mounting V4 +filesystems can now be disabled at kernel build time via Kconfig option. +The option will default to yes until September 2025, at which time it +will be changed to default to no. In September 2030, support will be +removed from the codebase entirely. + +Note: Distributors may choose to withdraw V4 format support earlier than +the dates listed above. Deprecated Mount Options ======================== @@ -217,6 +239,7 @@ Deprecated Mount Options =========================== ================ Name Removal Schedule =========================== ================ +Mounting with V4 filesystem September 2030 =========================== ================ |