xfs: remove obsolete osyncisosync mount option

Since Linux 2.6.33 the kernel has support for real O_SYNC, which made
the osyncisosync option a no-op.  Warn the users about this and remove
the mount flag for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 0 insertions, 11 deletions

diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index 9878f50d6ed6..7bff3e4f35df 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -131,17 +131,6 @@ When mounting an XFS filesystem, the following options are accepted.
         Don't check for double mounted file systems using the file system uuid.
         This is useful to mount LVM snapshot volumes.
 
-  osyncisosync
-        Make O_SYNC writes implement true O_SYNC.  WITHOUT this option,
-        Linux XFS behaves as if an "osyncisdsync" option is used,
-        which will make writes to files opened with the O_SYNC flag set
-        behave as if the O_DSYNC flag had been used instead.
-        This can result in better performance without compromising
-        data safety.
-        However if this option is not in effect, timestamp updates from
-        O_SYNC writes can be lost if the system crashes.
-        If timestamp updates are critical, use the osyncisosync option.
-
   uquota/usrquota/uqnoenforce/quota
         User disk quota accounting enabled, and limits (optionally)
         enforced.  Refer to xfs_quota(8) for further details.