3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jerry Lee <jerry...@qnap.com>
commit aec51758ce10a9c847a62a48a168f8c804c6e053 upstream.
On a 32-bit platform, the value of n_blcoks_count may be wrong during
the file system is resized to size larger than 2^32 blocks. This may
caused the superblock being corrupted with zero blocks count.
Fixes: 1c6bd7173d66
Signed-off-by: Jerry Lee <jerry...@qnap.com>
Signed-off-by: Theodore Ts'o <ty...@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/ext4/resize.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1929,7 +1929,8 @@ retry:
n_desc_blocks = o_desc_blocks +
le16_to_cpu(es->s_reserved_gdt_blocks);
n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
- n_blocks_count = n_group * EXT4_BLOCKS_PER_GROUP(sb);
+ n_blocks_count = (ext4_fsblk_t)n_group *
+ EXT4_BLOCKS_PER_GROUP(sb);
n_group--; /* set to last group number */
}
