[PATCH -V4 2/2] ext4: Use -1 as the fake block number for delayed new buffer_head

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Block number '0' should not be used as the fake block number for
the delayed new buffer. This will result in vfs calling umap_underlying_metadata for
block number '0'. So  use -1 instead.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

---
 fs/ext4/inode.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 12dcfab..c7c2156 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2318,7 +2318,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 			/* not enough space to reserve */
 			return ret;
 
-		map_bh(bh_result, inode->i_sb, 0);
+		map_bh(bh_result, inode->i_sb, -1);
 		set_buffer_new(bh_result);
 		set_buffer_delay(bh_result);
 	} else if (ret > 0) {
-- 
tg: (15262e5..) proper_mappingblock_for_delay (depends on: preallocate_corruption_quickfix)