From: Xin Yin yinxin.x@bytedance.com
commit 0b5b5a62b945a141e64011b2f90ee7e46f14be98 upstream.
For now ,we use ext4_punch_hole() during fast commit replay delete range procedure. But it will be affected by inode->i_size, which may not correct during fast commit replay procedure. The following test will failed.
-create & write foo (len 1000K) -falloc FALLOC_FL_ZERO_RANGE foo (range 400K - 600K) -create & fsync bar -falloc FALLOC_FL_PUNCH_HOLE foo (range 300K-500K) -fsync foo -crash before a full commit
After the fast_commit reply procedure, the range 400K-500K will not be removed. Because in this case, when calling ext4_punch_hole() the inode->i_size is 0, and it just retruns with doing nothing.
Change to use ext4_ext_remove_space() instead of ext4_punch_hole() to remove blocks of inode directly.
Signed-off-by: Xin Yin yinxin.x@bytedance.com Reviewed-by: Harshad Shirwadkar harshadshirwadkar@gmail.com Link: https://lore.kernel.org/r/20211223032337.5198-2-yinxin.x@bytedance.com Signed-off-by: Theodore Ts'o tytso@mit.edu Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/fast_commit.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
--- a/fs/ext4/fast_commit.c +++ b/fs/ext4/fast_commit.c @@ -1809,11 +1809,14 @@ ext4_fc_replay_del_range(struct super_bl } }
- ret = ext4_punch_hole(inode, - le32_to_cpu(lrange.fc_lblk) << sb->s_blocksize_bits, - le32_to_cpu(lrange.fc_len) << sb->s_blocksize_bits); - if (ret) - jbd_debug(1, "ext4_punch_hole returned %d", ret); + down_write(&EXT4_I(inode)->i_data_sem); + ret = ext4_ext_remove_space(inode, lrange.fc_lblk, + lrange.fc_lblk + lrange.fc_len - 1); + up_write(&EXT4_I(inode)->i_data_sem); + if (ret) { + iput(inode); + return 0; + } ext4_ext_replay_shrink_inode(inode, i_size_read(inode) >> sb->s_blocksize_bits); ext4_mark_inode_dirty(NULL, inode);