[XFS] write barrier support Issue all log sync operations as ordered

writes.  In addition flush the disk cache on fsync if the sync cached
operation didn't sync the log to disk (this requires some additional
bookeping in the transaction and log code). If the device doesn't claim to
support barriers, the filesystem has an extern log volume or the trial
superblock write with barriers enabled failed we disable barriers and
print a warning.  We should probably fail the mount completely, but that
could lead to nasty boot failures for the root filesystem.  Not enabled by
default yet, needs more destructive testing first.

SGI-PV: 912426
SGI-Modid: xfs-linux:xfs-kern:198723a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 92efe272b83..5e33891b804 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -661,10 +661,11 @@ xfs_trans_unreserve_and_mod_sb(
  */
  /*ARGSUSED*/
 int
-xfs_trans_commit(
+_xfs_trans_commit(
         xfs_trans_t     *tp,
         uint            flags,
-        xfs_lsn_t       *commit_lsn_p)
+        xfs_lsn_t       *commit_lsn_p,
+        int             *log_flushed)
 {
         xfs_log_iovec_t         *log_vector;
         int                     nvec;
@@ -893,9 +894,11 @@ shut_us_down:
          * log out now and wait for it.
          */
         if (sync) {
-                if (!error)
-                        error = xfs_log_force(mp, commit_lsn,
-                                      XFS_LOG_FORCE | XFS_LOG_SYNC);
+                if (!error) {
+                        error = _xfs_log_force(mp, commit_lsn,
+                                      XFS_LOG_FORCE | XFS_LOG_SYNC,
+                                      log_flushed);
+                }
                 XFS_STATS_INC(xs_trans_sync);
         } else {
                 XFS_STATS_INC(xs_trans_async);