hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9DN5Z CVE: NA

--------------------------------

Since commit 7f6416dcd4a3f ("ext4: implement writeback iomap path"), the order mode is removed in iomap framework, which lets ext4_mb_clear_bb() free data blocks immediately. It may cause stale data read from truncated file in power-cut case. Following is details: P1 P2 vfs_truncate(file A) ext4_setattr EXT4_I(inode)->i_disksize = attr->ia_size // record in journal ext4_truncate ext4_mb_clear_bb mb_free_blocks // free block i vfs_write(file B) // get block i and writeback >> powercut << In the next mount, inode size and extent tree is stale(before truncated), the content in block i is file B. Fix the problem by adding free data blocks in journal for iomap case.

Fixes: 7f6416dcd4a3 ("ext4: implement writeback iomap path") Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Zhihao Cheng chengzhihao@huaweicloud.com --- fs/ext4/mballoc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b138902fd42c..4d34e2b33fa0 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -6624,7 +6624,8 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode, */ if (ext4_handle_valid(handle) && ((flags & EXT4_FREE_BLOCKS_METADATA) || - !ext4_should_writeback_data(inode))) { + !ext4_should_writeback_data(inode) || + ext4_test_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP))) { struct ext4_free_data *new_entry; /* * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed