gfs2: replace barriers with explicit flush / FUA usage

Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 5 insertions, 14 deletions

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index cde1248a6225..9c65170e932e 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -592,22 +592,13 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
         lh->lh_hash = cpu_to_be32(hash);
 
         bh->b_end_io = end_buffer_write_sync;
-        if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
-                goto skip_barrier;
         get_bh(bh);
-        submit_bh(WRITE_BARRIER | REQ_META, bh);
-        wait_on_buffer(bh);
-        if (buffer_eopnotsupp(bh)) {
-                clear_buffer_eopnotsupp(bh);
-                set_buffer_uptodate(bh);
-                fs_info(sdp, "barrier sync failed - disabling barriers\n");
-                set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
-                lock_buffer(bh);
-skip_barrier:
-                get_bh(bh);
+        if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
                 submit_bh(WRITE_SYNC | REQ_META, bh);
-                wait_on_buffer(bh);
-        }
+        else
+                submit_bh(WRITE_FLUSH_FUA | REQ_META, bh);
+        wait_on_buffer(bh);
+
         if (!buffer_uptodate(bh))
                 gfs2_io_error_bh(sdp, bh);
         brelse(bh);