ext4: use ext4_ext_remove_space() for fast commit replay delete range

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

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index dd002facf6c9548ac768e009da47fb2fb1da8ace..28ddeb1d6afb913f58e5916e44514b633d2c8d51 100644 (file)
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1770,11 +1770,14 @@ ext4_fc_replay_del_range(struct super_block *sb, struct ext4_fc_tl *tl,
                }
        }
 
-       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);