ext4: Properly initialize the buffer_head state

These struct buffer_heads are allocated on the stack (and hence are
initialized with stack garbage).  They are only used to call a
get_blocks() function, so that's mostly OK, but b_state must be
initialized to be 0 so we don't have any unexpected BH_* flags set by
accident, such as BH_Unwritten or BH_Delay.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e3a55eb8b26a..a953214f2829 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3150,6 +3150,7 @@ retry:
                         ret = PTR_ERR(handle);
                         break;
                 }
+                map_bh.b_state = 0;
                 ret = ext4_get_blocks_wrap(handle, inode, block,
                                           max_blocks, &map_bh,
                                           EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);