On Fri, Nov 08, 2024 at 08:27:38PM +0800, Long Li wrote: > After reboot, file has zero padding in range [A+B, A+B+C]: > > |< Block Size (BS) >| > |DDDDDDDDDDDDDDDD0000000000000000| > ^ ^ ^ > A A+B A+B+C (EOF) > > D = Valid Data > 0 = Zero Padding > > The issue stems from disk size being set to min(io_offset + io_size, > inode->i_size) at I/O completion. Since io_offset+io_size is block > size granularity, it may exceed the actual valid file data size. In > the case of concurrent append writes, inode->i_size may be larger > than the actual range of valid file data written to disk, leading to > inaccurate disk size updates. Oh, interesting one. Do you have a reproducer we could wire up to xfstests? > This patch introduce ioend->io_end to trace the end position of the > valid data in ioend, rather than solely relying on ioend->io_size. > It ensures more precise disk size updates and avoids the zero padding > issue. Another benefit is that it makes the xfs_ioend_is_append() > check more accurate, which can reduce unnecessary end bio callbacks > of xfs_end_bio() in certain scenarios, such as repeated writes at the > file tail without extending the file size. Hmm. Can we do away with two members for the size by just rounding up the block size for the block based operations?
