ext4: properly sync file size update after O_SYNC direct IO
Gao Xiang has reported that on ext4 O_SYNC direct IO does not properly sync file size update and thus if we crash at unfortunate moment, the file can have smaller size although O_SYNC IO has reported successful completion. The problem happens because update of on-disk inode size is handled in ext4_dio_write_iter() *after* iomap_dio_rw() (and thus dio_complete() in particular) has returned and generic_file_sync() gets called by dio_complete(). Fix the problem by handling on-disk inode size update directly in our ->end_io completion handler. References: https://lore.kernel.org/all/02d18236-26ef-09b0-90ad-030c4fe3ee20@linux.alibaba.com Reported-by:Gao Xiang <hsiangkao@linux.alibaba.com> CC: stable@vger.kernel.org Fixes: 378f32ba ("ext4: introduce direct I/O write using iomap infrastructure") Signed-off-by:
Jan Kara <jack@suse.cz> Tested-by:
Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by:
"Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20231013121350.26872-1-jack@suse.cz Signed-off-by:
Theodore Ts'o <tytso@mit.edu>
parent
ce56d213