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>

2 files changed, 7 insertions, 17 deletions

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index cde1248a622..9c65170e932 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);
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 171a744f8e4..37931647291 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -854,8 +854,7 @@ static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
                                 if ((start + nr_sects) != blk) {
                                         rv = blkdev_issue_discard(bdev, start,
                                                             nr_sects, GFP_NOFS,
-                                                            BLKDEV_IFL_WAIT |
-                                                            BLKDEV_IFL_BARRIER);
+                                                            BLKDEV_IFL_WAIT);
                                         if (rv)
                                                 goto fail;
                                         nr_sects = 0;
@@ -870,7 +869,7 @@ start_new_extent:
         }
         if (nr_sects) {
                 rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS,
-                                         BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+                                         BLKDEV_IFL_WAIT);
                 if (rv)
                         goto fail;
         }