btrfs: 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: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 4 insertions, 15 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 64f10082f048..5e789f4a3ed0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2063,7 +2063,7 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
         if (uptodate) {
                 set_buffer_uptodate(bh);
         } else {
-                if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+                if (printk_ratelimit()) {
                         printk(KERN_WARNING "lost page write due to "
                                         "I/O error on %s\n",
                                        bdevname(bh->b_bdev, b));
@@ -2200,21 +2200,10 @@ static int write_dev_supers(struct btrfs_device *device,
                         bh->b_end_io = btrfs_end_buffer_write_sync;
                 }
 
-                if (i == last_barrier && do_barriers && device->barriers) {
-                        ret = submit_bh(WRITE_BARRIER, bh);
-                        if (ret == -EOPNOTSUPP) {
-                                printk("btrfs: disabling barriers on dev %s\n",
-                                       device->name);
-                                set_buffer_uptodate(bh);
-                                device->barriers = 0;
-                                /* one reference for submit_bh */
-                                get_bh(bh);
-                                lock_buffer(bh);
-                                ret = submit_bh(WRITE_SYNC, bh);
-                        }
-                } else {
+                if (i == last_barrier && do_barriers)
+                        ret = submit_bh(WRITE_FLUSH_FUA, bh);
+                else
                         ret = submit_bh(WRITE_SYNC, bh);
-                }
 
                 if (ret)
                         errors++;