On sudden f2fs shutdown, zoned block device status and f2fs meta data can be inconsistent. When f2fs shutdown happens during write operations, write pointers on the device go forward but the f2fs meta data does not reflect the write pointer progress. This inconsistency will eventually cause "Unaligned write command" error when restarting write operation after the next mount.
This error is observed with xfstests test case generic/388, which enforces sudden shutdown during write operation and checks the file system recovery. This patch series adds a feature to fsck.f2fs to check and fix the inconsistency. Per discussion on the list, implement two checks. The first check is for open zones that current segments point to. Check write pointer consistency with current segment positions recorded in CP, and if they are inconsistent, assign a new zone to the current segment. The second check is for non-open zones that current segments do not point to. Check write pointer consistency with valid block maps recorded in SIT. Reflect fsync data blocks in these checks. If fsync data exists and current segments point to zones with fsync data, keep the fsync data and the current segments untouched so that kernel can recover the fsync data. Another patch series for kernel is being posted to check and fix write pointer consistency after fsync data recovery. Have fsck check and fix the consistency twice. The first fix is at the beginning of fsck so that write by fsck for fix do not fail with unaligned write command error. The second fix is at the end of the fsck to reflect SIT valid block maps updates by fsck. The first three patches add three helper functions to call report zone and reset zone commands to zoned block devices. Next three patches modify existing fsck functions to meet zoned block devices' requirements. The last two patches add the two checks for write pointer consistency. Thank goes to Chao Yu for the detailed discussion on the list. Changes from v4: * Renewed the series based on design discussion on the list Changes from v3: * Set curseg position at a new zone start when its write pointer is at zone end Changes from v2: * Reflected review comments by Chao Yu * Dropped 4th patch and 2nd patch (2nd patch was required for the 4th patch) Changes from v1: * Fixed build failure on dev branch Shin'ichiro Kawasaki (8): libf2fs_zoned: Introduce f2fs_report_zones() helper function libf2fs_zoned: Introduce f2fs_report_zone() helper function libf2fs_zoned: Introduce f2fs_reset_zone() helper function fsck: Find free zones instead of blocks to assign to current segments fsck: Introduce move_one_curseg_info() function fsck: Check fsync data always for zoned block devices fsck: Check write pointer consistency of open zones fsck: Check write pointer consistency of non-open zones fsck/defrag.c | 2 +- fsck/f2fs.h | 5 + fsck/fsck.c | 270 ++++++++++++++++++++++++++++++++++++++++++++ fsck/fsck.h | 11 +- fsck/main.c | 2 + fsck/mount.c | 137 +++++++++++++++------- fsck/segment.c | 4 +- include/f2fs_fs.h | 7 ++ lib/libf2fs_zoned.c | 118 +++++++++++++++++++ 9 files changed, 512 insertions(+), 44 deletions(-) -- 2.21.0 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
