reiserfs: replace barriers with explicit flush / FUA usage

Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers.  Note that reiserfs had a fairly different code
path for barriers before as it wa the only filesystem actually making use
of them.  The new code always uses the old non-barrier codepath and just
sets the WRITE_FLUSH_FUA explicitly for the journal commits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
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, 20 insertions, 86 deletions

diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 812e2c05aa29..076c8b194682 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -138,13 +138,6 @@ static int reiserfs_clean_and_file_buffer(struct buffer_head *bh)
         return 0;
 }
 
-static void disable_barrier(struct super_block *s)
-{
-        REISERFS_SB(s)->s_mount_opt &= ~(1 << REISERFS_BARRIER_FLUSH);
-        printk("reiserfs: disabling flush barriers on %s\n",
-               reiserfs_bdevname(s));
-}
-
 static struct reiserfs_bitmap_node *allocate_bitmap_node(struct super_block
                                                          *sb)
 {
@@ -677,30 +670,6 @@ static void submit_ordered_buffer(struct buffer_head *bh)
         submit_bh(WRITE, bh);
 }
 
-static int submit_barrier_buffer(struct buffer_head *bh)
-{
-        get_bh(bh);
-        bh->b_end_io = reiserfs_end_ordered_io;
-        clear_buffer_dirty(bh);
-        if (!buffer_uptodate(bh))
-                BUG();
-        return submit_bh(WRITE_BARRIER, bh);
-}
-
-static void check_barrier_completion(struct super_block *s,
-                                     struct buffer_head *bh)
-{
-        if (buffer_eopnotsupp(bh)) {
-                clear_buffer_eopnotsupp(bh);
-                disable_barrier(s);
-                set_buffer_uptodate(bh);
-                set_buffer_dirty(bh);
-                reiserfs_write_unlock(s);
-                sync_dirty_buffer(bh);
-                reiserfs_write_lock(s);
-        }
-}
-
 #define CHUNK_SIZE 32
 struct buffer_chunk {
         struct buffer_head *bh[CHUNK_SIZE];
@@ -1009,7 +978,6 @@ static int flush_commit_list(struct super_block *s,
         struct buffer_head *tbh = NULL;
         unsigned int trans_id = jl->j_trans_id;
         struct reiserfs_journal *journal = SB_JOURNAL(s);
-        int barrier = 0;
         int retval = 0;
         int write_len;
 
@@ -1094,24 +1062,6 @@ static int flush_commit_list(struct super_block *s,
         }
         atomic_dec(&journal->j_async_throttle);
 
-        /* We're skipping the commit if there's an error */
-        if (retval || reiserfs_is_journal_aborted(journal))
-                barrier = 0;
-
-        /* wait on everything written so far before writing the commit
-         * if we are in barrier mode, send the commit down now
-         */
-        barrier = reiserfs_barrier_flush(s);
-        if (barrier) {
-                int ret;
-                lock_buffer(jl->j_commit_bh);
-                ret = submit_barrier_buffer(jl->j_commit_bh);
-                if (ret == -EOPNOTSUPP) {
-                        set_buffer_uptodate(jl->j_commit_bh);
-                        disable_barrier(s);
-                        barrier = 0;
-                }
-        }
         for (i = 0; i < (jl->j_len + 1); i++) {
                 bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
                     (jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
@@ -1143,27 +1093,22 @@ static int flush_commit_list(struct super_block *s,
 
         BUG_ON(atomic_read(&(jl->j_commit_left)) != 1);
 
-        if (!barrier) {
-                /* If there was a write error in the journal - we can't commit
-                 * this transaction - it will be invalid and, if successful,
-                 * will just end up propagating the write error out to
-                 * the file system. */
-                if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
-                        if (buffer_dirty(jl->j_commit_bh))
-                                BUG();
-                        mark_buffer_dirty(jl->j_commit_bh) ;
-                        reiserfs_write_unlock(s);
-                        sync_dirty_buffer(jl->j_commit_bh) ;
-                        reiserfs_write_lock(s);
-                }
-        } else {
+        /* If there was a write error in the journal - we can't commit
+         * this transaction - it will be invalid and, if successful,
+         * will just end up propagating the write error out to
+         * the file system. */
+        if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
+                if (buffer_dirty(jl->j_commit_bh))
+                        BUG();
+                mark_buffer_dirty(jl->j_commit_bh) ;
                 reiserfs_write_unlock(s);
-                wait_on_buffer(jl->j_commit_bh);
+                if (reiserfs_barrier_flush(s))
+                        __sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
+                else
+                        sync_dirty_buffer(jl->j_commit_bh);
                 reiserfs_write_lock(s);
         }
 
-        check_barrier_completion(s, jl->j_commit_bh);
-
         /* If there was a write error in the journal - we can't commit this
          * transaction - it will be invalid and, if successful, will just end
          * up propagating the write error out to the filesystem. */
@@ -1319,26 +1264,15 @@ static int _update_journal_header_block(struct super_block *sb,
                 jh->j_first_unflushed_offset = cpu_to_le32(offset);
                 jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
 
-                if (reiserfs_barrier_flush(sb)) {
-                        int ret;
-                        lock_buffer(journal->j_header_bh);
-                        ret = submit_barrier_buffer(journal->j_header_bh);
-                        if (ret == -EOPNOTSUPP) {
-                                set_buffer_uptodate(journal->j_header_bh);
-                                disable_barrier(sb);
-                                goto sync;
-                        }
-                        reiserfs_write_unlock(sb);
-                        wait_on_buffer(journal->j_header_bh);
-                        reiserfs_write_lock(sb);
-                        check_barrier_completion(sb, journal->j_header_bh);
-                } else {
-                      sync:
-                        set_buffer_dirty(journal->j_header_bh);
-                        reiserfs_write_unlock(sb);
+                set_buffer_dirty(journal->j_header_bh);
+                reiserfs_write_unlock(sb);
+
+                if (reiserfs_barrier_flush(sb))
+                        __sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
+                else
                         sync_dirty_buffer(journal->j_header_bh);
-                        reiserfs_write_lock(sb);
-                }
+
+                reiserfs_write_lock(sb);
                 if (!buffer_uptodate(journal->j_header_bh)) {
                         reiserfs_warning(sb, "journal-837",
                                          "IO error during journal replay");