1 files changed, 24 insertions, 8 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 5c23ef5..d48caee 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -821,7 +821,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 				 * contents - it is a noop if I/O is still in
 				 * flight on potentially older contents.
 				 */
-				ll_rw_block(SWRITE, 1, &bh);
+				ll_rw_block(SWRITE_SYNC, 1, &bh);
 				brelse(bh);
 				spin_lock(lock);
 			}
@@ -1691,11 +1691,13 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 			 */
 			clear_buffer_dirty(bh);
 			set_buffer_uptodate(bh);
-		} else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
+		} else if ((!buffer_mapped(bh) || buffer_delay(bh)) &&
+			   buffer_dirty(bh)) {
 			WARN_ON(bh->b_size != blocksize);
 			err = get_block(inode, block, bh, 1);
 			if (err)
 				goto recover;
+			clear_buffer_delay(bh);
 			if (buffer_new(bh)) {
 				/* blockdev mappings never come here */
 				clear_buffer_new(bh);
@@ -1774,7 +1776,8 @@ recover:
 	bh = head;
 	/* Recovery: lock and submit the mapped buffers */
 	do {
-		if (buffer_mapped(bh) && buffer_dirty(bh)) {
+		if (buffer_mapped(bh) && buffer_dirty(bh) &&
+		    !buffer_delay(bh)) {
 			lock_buffer(bh);
 			mark_buffer_async_write(bh);
 		} else {
@@ -2061,6 +2064,7 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 			struct page *page, void *fsdata)
 {
 	struct inode *inode = mapping->host;
+	int i_size_changed = 0;
 
 	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
 
@@ -2073,12 +2077,21 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 	 */
 	if (pos+copied > inode->i_size) {
 		i_size_write(inode, pos+copied);
-		mark_inode_dirty(inode);
+		i_size_changed = 1;
 	}
 
 	unlock_page(page);
 	page_cache_release(page);
 
+	/*
+	 * Don't mark the inode dirty under page lock. First, it unnecessarily
+	 * makes the holding time of page lock longer. Second, it forces lock
+	 * ordering of page lock and transaction start for journaling
+	 * filesystems.
+	 */
+	if (i_size_changed)
+		mark_inode_dirty(inode);
+
 	return copied;
 }
 EXPORT_SYMBOL(generic_write_end);
@@ -2940,16 +2953,19 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 	for (i = 0; i < nr; i++) {
 		struct buffer_head *bh = bhs[i];
 
-		if (rw == SWRITE)
+		if (rw == SWRITE || rw == SWRITE_SYNC)
 			lock_buffer(bh);
 		else if (test_set_buffer_locked(bh))
 			continue;
 
-		if (rw == WRITE || rw == SWRITE) {
+		if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC) {
 			if (test_clear_buffer_dirty(bh)) {
 				bh->b_end_io = end_buffer_write_sync;
 				get_bh(bh);
-				submit_bh(WRITE, bh);
+				if (rw == SWRITE_SYNC)
+					submit_bh(WRITE_SYNC, bh);
+				else
+					submit_bh(WRITE, bh);
 				continue;
 			}
 		} else {
@@ -2978,7 +2994,7 @@ 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, bh);
+		ret = submit_bh(WRITE_SYNC, bh);
 		wait_on_buffer(bh);
 		if (buffer_eopnotsupp(bh)) {
 			clear_buffer_eopnotsupp(bh);