xfs: share more code in xfs_buffered_write_iomap_begin

Introduce a local iomap_flags variable so that the code allocating new
delalloc blocks in the data fork can fall through to the found_imap
label and reuse the code to unlock and fill the iomap.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

fs/xfs/xfs_iomap.c

@@ -975,6 +975,7 @@ xfs_buffered_write_iomap_begin(
 	int			allocfork = XFS_DATA_FORK;
 	int			error = 0;
 	unsigned int		lockmode = XFS_ILOCK_EXCL;
+	unsigned int		iomap_flags = 0;
 	u64			seq;
 
 	if (xfs_is_shutdown(mp))
@@ -1145,6 +1146,11 @@ xfs_buffered_write_iomap_begin(
 		}
 	}
 
+	/*
+	 * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
+	 * them out if the write happens to fail.
+	 */
+	iomap_flags |= IOMAP_F_NEW;
 	if (allocfork == XFS_COW_FORK) {
 		error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb,
 				end_fsb - offset_fsb, prealloc_blocks, &cmap,
@@ -1162,19 +1168,11 @@ xfs_buffered_write_iomap_begin(
 	if (error)
 		goto out_unlock;
 
-	/*
-	 * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
-	 * them out if the write happens to fail.
-	 */
-	seq = xfs_iomap_inode_sequence(ip, IOMAP_F_NEW);
-	xfs_iunlock(ip, lockmode);
 	trace_xfs_iomap_alloc(ip, offset, count, allocfork, &imap);
-	return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, IOMAP_F_NEW, seq);
-
 found_imap:
-	seq = xfs_iomap_inode_sequence(ip, 0);
+	seq = xfs_iomap_inode_sequence(ip, iomap_flags);
 	xfs_iunlock(ip, lockmode);
-	return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, 0, seq);
+	return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq);
 
 convert_delay:
 	xfs_iunlock(ip, lockmode);