kill BH_Ordered flag

Instead of abusing a buffer_head flag just add a variant of
sync_dirty_buffer which allows passing the exact type of write
flag required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 62 insertions, 71 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 50efa339e051..6c8ad977f3d4 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2912,13 +2912,6 @@ int submit_bh(int rw, struct buffer_head * bh)
         BUG_ON(buffer_unwritten(bh));
 
         /*
-         * Mask in barrier bit for a write (could be either a WRITE or a
-         * WRITE_SYNC
-         */
-        if (buffer_ordered(bh) && (rw & WRITE))
-                rw |= WRITE_BARRIER;
-
-        /*
          * Only clear out a write error when rewriting
          */
         if (test_set_buffer_req(bh) && (rw & WRITE))
@@ -3021,7 +3014,7 @@ EXPORT_SYMBOL(ll_rw_block);
  * and then start new I/O and then wait upon it.  The caller must have a ref on
  * the buffer_head.
  */
-int sync_dirty_buffer(struct buffer_head *bh)
+int __sync_dirty_buffer(struct buffer_head *bh, int rw)
 {
         int ret = 0;
 
@@ -3030,7 +3023,7 @@ int sync_dirty_buffer(struct buffer_head *bh)
         if (test_clear_buffer_dirty(bh)) {
                 get_bh(bh);
                 bh->b_end_io = end_buffer_write_sync;
-                ret = submit_bh(WRITE_SYNC, bh);
+                ret = submit_bh(rw, bh);
                 wait_on_buffer(bh);
                 if (buffer_eopnotsupp(bh)) {
                         clear_buffer_eopnotsupp(bh);
@@ -3043,6 +3036,12 @@ int sync_dirty_buffer(struct buffer_head *bh)
         }
         return ret;
 }
+EXPORT_SYMBOL(__sync_dirty_buffer);
+
+int sync_dirty_buffer(struct buffer_head *bh)
+{
+        return __sync_dirty_buffer(bh, WRITE_SYNC);
+}
 EXPORT_SYMBOL(sync_dirty_buffer);
 
 /*
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 28a9ddaa0c49..95d8c11c929e 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -119,7 +119,6 @@ static int journal_write_commit_record(journal_t *journal,
         struct buffer_head *bh;
         journal_header_t *header;
         int ret;
-        int barrier_done = 0;
 
         if (is_journal_aborted(journal))
                 return 0;
@@ -137,34 +136,36 @@ static int journal_write_commit_record(journal_t *journal,
 
         JBUFFER_TRACE(descriptor, "write commit block");
         set_buffer_dirty(bh);
+
         if (journal->j_flags & JFS_BARRIER) {
-                set_buffer_ordered(bh);
-                barrier_done = 1;
-        }
-        ret = sync_dirty_buffer(bh);
-        if (barrier_done)
-                clear_buffer_ordered(bh);
-        /* is it possible for another commit to fail at roughly
-         * the same time as this one?  If so, we don't want to
-         * trust the barrier flag in the super, but instead want
-         * to remember if we sent a barrier request
-         */
-        if (ret == -EOPNOTSUPP && barrier_done) {
-                char b[BDEVNAME_SIZE];
+                ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER);
 
-                printk(KERN_WARNING
-                        "JBD: barrier-based sync failed on %s - "
-                        "disabling barriers\n",
-                        bdevname(journal->j_dev, b));
-                spin_lock(&journal->j_state_lock);
-                journal->j_flags &= ~JFS_BARRIER;
-                spin_unlock(&journal->j_state_lock);
+                /*
+                 * Is it possible for another commit to fail at roughly
+                 * the same time as this one?  If so, we don't want to
+                 * trust the barrier flag in the super, but instead want
+                 * to remember if we sent a barrier request
+                 */
+                if (ret == -EOPNOTSUPP) {
+                        char b[BDEVNAME_SIZE];
 
-                /* And try again, without the barrier */
-                set_buffer_uptodate(bh);
-                set_buffer_dirty(bh);
+                        printk(KERN_WARNING
+                                "JBD: barrier-based sync failed on %s - "
+                                "disabling barriers\n",
+                                bdevname(journal->j_dev, b));
+                        spin_lock(&journal->j_state_lock);
+                        journal->j_flags &= ~JFS_BARRIER;
+                        spin_unlock(&journal->j_state_lock);
+
+                        /* And try again, without the barrier */
+                        set_buffer_uptodate(bh);
+                        set_buffer_dirty(bh);
+                        ret = sync_dirty_buffer(bh);
+                }
+        } else {
                 ret = sync_dirty_buffer(bh);
         }
+
         put_bh(bh);             /* One for getblk() */
         journal_put_journal_head(descriptor);
 
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index f52e5e8049f1..7c068c189d80 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -101,7 +101,6 @@ static int journal_submit_commit_record(journal_t *journal,
         struct commit_header *tmp;
         struct buffer_head *bh;
         int ret;
-        int barrier_done = 0;
         struct timespec now = current_kernel_time();
 
         if (is_journal_aborted(journal))
@@ -136,30 +135,22 @@ static int journal_submit_commit_record(journal_t *journal,
         if (journal->j_flags & JBD2_BARRIER &&
             !JBD2_HAS_INCOMPAT_FEATURE(journal,
                                        JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
-                set_buffer_ordered(bh);
-                barrier_done = 1;
-        }
-        ret = submit_bh(WRITE_SYNC_PLUG, bh);
-        if (barrier_done)
-                clear_buffer_ordered(bh);
-
-        /* is it possible for another commit to fail at roughly
-         * the same time as this one?  If so, we don't want to
-         * trust the barrier flag in the super, but instead want
-         * to remember if we sent a barrier request
-         */
-        if (ret == -EOPNOTSUPP && barrier_done) {
-                printk(KERN_WARNING
-                       "JBD2: Disabling barriers on %s, "
-                       "not supported by device\n", journal->j_devname);
-                write_lock(&journal->j_state_lock);
-                journal->j_flags &= ~JBD2_BARRIER;
-                write_unlock(&journal->j_state_lock);
+                ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh);
+                if (ret == -EOPNOTSUPP) {
+                        printk(KERN_WARNING
+                               "JBD2: Disabling barriers on %s, "
+                               "not supported by device\n", journal->j_devname);
+                        write_lock(&journal->j_state_lock);
+                        journal->j_flags &= ~JBD2_BARRIER;
+                        write_unlock(&journal->j_state_lock);
 
-                /* And try again, without the barrier */
-                lock_buffer(bh);
-                set_buffer_uptodate(bh);
-                clear_buffer_dirty(bh);
+                        /* And try again, without the barrier */
+                        lock_buffer(bh);
+                        set_buffer_uptodate(bh);
+                        clear_buffer_dirty(bh);
+                        ret = submit_bh(WRITE_SYNC_PLUG, bh);
+                }
+        } else {
                 ret = submit_bh(WRITE_SYNC_PLUG, bh);
         }
         *cbh = bh;
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 1fa86b9df73b..68345430fb48 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -175,24 +175,24 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 {
         struct the_nilfs *nilfs = sbi->s_nilfs;
         int err;
-        int barrier_done = 0;
 
-        if (nilfs_test_opt(sbi, BARRIER)) {
-                set_buffer_ordered(nilfs->ns_sbh[0]);
-                barrier_done = 1;
-        }
  retry:
         set_buffer_dirty(nilfs->ns_sbh[0]);
-        err = sync_dirty_buffer(nilfs->ns_sbh[0]);
-        if (err == -EOPNOTSUPP && barrier_done) {
-                nilfs_warning(sbi->s_super, __func__,
-                              "barrier-based sync failed. "
-                              "disabling barriers\n");
-                nilfs_clear_opt(sbi, BARRIER);
-                barrier_done = 0;
-                clear_buffer_ordered(nilfs->ns_sbh[0]);
-                goto retry;
+
+        if (nilfs_test_opt(sbi, BARRIER)) {
+                err = __sync_dirty_buffer(nilfs->ns_sbh[0],
+                                          WRITE_SYNC | WRITE_BARRIER);
+                if (err == -EOPNOTSUPP) {
+                        nilfs_warning(sbi->s_super, __func__,
+                                      "barrier-based sync failed. "
+                                      "disabling barriers\n");
+                        nilfs_clear_opt(sbi, BARRIER);
+                        goto retry;
+                }
+        } else {
+                err = sync_dirty_buffer(nilfs->ns_sbh[0]);
         }
+
         if (unlikely(err)) {
                 printk(KERN_ERR
                        "NILFS: unable to write superblock (err=%d)\n", err);