diff options
| author | Qu Wenruo <quwenruo@cn.fujitsu.com> | 2014-01-06 09:58:25 +0800 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-01-28 13:20:16 -0800 |
| commit | 842bef5891aaf13e2dede01d86397d810fde2dd8 (patch) | |
| tree | 33b072d33c9c2479cf78e0fdc31bb8be03985349 /Documentation/filesystems | |
| parent | e8117c26b24098496b6011aabe84e43e0189a506 (diff) | |
| download | op-kernel-dev-842bef5891aaf13e2dede01d86397d810fde2dd8.zip op-kernel-dev-842bef5891aaf13e2dede01d86397d810fde2dd8.tar.gz | |
btrfs: Add "barrier" option to support "-o remount,barrier"
Btrfs can be remounted without barrier, but there is no "barrier" option
so nobody can remount btrfs back with barrier on. Only umount and
mount again can re-enable barrier.(Quite awkward)
Also the mount options in the document is also changed slightly for the
further pairing options changes.
Reported-by: Daniel Blueman <daniel@quora.org>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Mike Fleetwood <mike.fleetwood@googlemail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/btrfs.txt | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/filesystems/btrfs.txt b/Documentation/filesystems/btrfs.txt index 5dd282d..ce487a2 100644 --- a/Documentation/filesystems/btrfs.txt +++ b/Documentation/filesystems/btrfs.txt @@ -38,7 +38,7 @@ Mount Options ============= When mounting a btrfs filesystem, the following option are accepted. -Unless otherwise specified, all options default to off. +Options with (*) are default options and will not show in the mount options. alloc_start=<bytes> Debugging option to force all block allocations above a certain @@ -138,12 +138,13 @@ Unless otherwise specified, all options default to off. Disable support for Posix Access Control Lists (ACLs). See the acl(5) manual page for more information about ACLs. + barrier(*) nobarrier - Disables the use of block layer write barriers. Write barriers ensure - that certain IOs make it through the device cache and are on persistent - storage. If used on a device with a volatile (non-battery-backed) - write-back cache, this option will lead to filesystem corruption on a - system crash or power loss. + Enable/disable the use of block layer write barriers. Write barriers + ensure that certain IOs make it through the device cache and are on + persistent storage. If disabled on a device with a volatile + (non-battery-backed) write-back cache, nobarrier option will lead to + filesystem corruption on a system crash or power loss. nodatacow Disable data copy-on-write for newly created files. Implies nodatasum, |
