1. 21 Feb, 2024 19 commits
  2. 20 Feb, 2024 2 commits
  3. 19 Feb, 2024 4 commits
  4. 17 Feb, 2024 3 commits
    • Long Li's avatar
      xfs: ensure submit buffers on LSN boundaries in error handlers · e4c3b72a
      Long Li authored
      While performing the IO fault injection test, I caught the following data
      corruption report:
      
       XFS (dm-0): Internal error ltbno + ltlen > bno at line 1957 of file fs/xfs/libxfs/xfs_alloc.c.  Caller xfs_free_ag_extent+0x79c/0x1130
       CPU: 3 PID: 33 Comm: kworker/3:0 Not tainted 6.5.0-rc7-next-20230825-00001-g7f8666926889 #214
       Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
       Workqueue: xfs-inodegc/dm-0 xfs_inodegc_worker
       Call Trace:
        <TASK>
        dump_stack_lvl+0x50/0x70
        xfs_corruption_error+0x134/0x150
        xfs_free_ag_extent+0x7d3/0x1130
        __xfs_free_extent+0x201/0x3c0
        xfs_trans_free_extent+0x29b/0xa10
        xfs_extent_free_finish_item+0x2a/0xb0
        xfs_defer_finish_noroll+0x8d1/0x1b40
        xfs_defer_finish+0x21/0x200
        xfs_itruncate_extents_flags+0x1cb/0x650
        xfs_free_eofblocks+0x18f/0x250
        xfs_inactive+0x485/0x570
        xfs_inodegc_worker+0x207/0x530
        process_scheduled_works+0x24a/0xe10
        worker_thread+0x5ac/0xc60
        kthread+0x2cd/0x3c0
        ret_from_fork+0x4a/0x80
        ret_from_fork_asm+0x11/0x20
        </TASK>
       XFS (dm-0): Corruption detected. Unmount and run xfs_repair
      
      After analyzing the disk image, it was found that the corruption was
      triggered by the fact that extent was recorded in both inode datafork
      and AGF btree blocks. After a long time of reproduction and analysis,
      we found that the reason of free sapce btree corruption was that the
      AGF btree was not recovered correctly.
      
      Consider the following situation, Checkpoint A and Checkpoint B are in
      the same record and share the same start LSN1, buf items of same object
      (AGF btree block) is included in both Checkpoint A and Checkpoint B. If
      the buf item in Checkpoint A has been recovered and updates metadata LSN
      permanently, then the buf item in Checkpoint B cannot be recovered,
      because log recovery skips items with a metadata LSN >= the current LSN
      of the recovery item. If there is still an inode item in Checkpoint B
      that records the Extent X, the Extent X will be recorded in both inode
      datafork and AGF btree block after Checkpoint B is recovered. Such
      transaction can be seen when allocing enxtent for inode bmap, it record
      both the addition of extent to the inode extent list and the removing
      extent from the AGF.
      
        |------------Record (LSN1)------------------|---Record (LSN2)---|
        |-------Checkpoint A----------|----------Checkpoint B-----------|
        |     Buf Item(Extent X)      | Buf Item / Inode item(Extent X) |
        |     Extent X is freed       |     Extent X is allocated       |
      
      After commit 12818d24 ("xfs: rework log recovery to submit buffers
      on LSN boundaries") was introduced, we submit buffers on lsn boundaries
      during log recovery. The above problem can be avoided under normal paths,
      but it's not guaranteed under abnormal paths. Consider the following
      process, if an error was encountered after recover buf item in Checkpoint
      A and before recover buf item in Checkpoint B, buffers that have been
      added to the buffer_list will still be submitted, this violates the
      submits rule on lsn boundaries. So buf item in Checkpoint B cannot be
      recovered on the next mount due to current lsn of transaction equal to
      metadata lsn on disk. The detailed process of the problem is as follows.
      
      First Mount:
      
        xlog_do_recovery_pass
          error = xlog_recover_process
            xlog_recover_process_data
              xlog_recover_process_ophdr
                xlog_recovery_process_trans
                  ...
                    /* recover buf item in Checkpoint A */
                    xlog_recover_buf_commit_pass2
                      xlog_recover_do_reg_buffer
                      /* add buffer of agf btree block to buffer_list */
                      xfs_buf_delwri_queue(bp, buffer_list)
                  ...
                  ==> Encounter read IO error and return
          /* submit buffers regardless of error */
          if (!list_empty(&buffer_list))
            xfs_buf_delwri_submit(&buffer_list);
      
          <buf items of agf btree block in Checkpoint A recovery success>
      
      Second Mount:
      
        xlog_do_recovery_pass
          error = xlog_recover_process
            xlog_recover_process_data
              xlog_recover_process_ophdr
                xlog_recovery_process_trans
                  ...
                    /* recover buf item in Checkpoint B */
                    xlog_recover_buf_commit_pass2
                      /* buffer of agf btree block wouldn't added to
                         buffer_list due to lsn equal to current_lsn */
                      if (XFS_LSN_CMP(lsn, current_lsn) >= 0)
                        goto out_release
      
          <buf items of agf btree block in Checkpoint B wouldn't recovery>
      
      In order to make sure that submits buffers on lsn boundaries in the
      abnormal paths, we need to check error status before submit buffers that
      have been added from the last record processed. If error status exist,
      buffers in the bufffer_list should not be writen to disk.
      
      Canceling the buffers in the buffer_list directly isn't correct, unlike
      any other place where write list was canceled, these buffers has been
      initialized by xfs_buf_item_init() during recovery and held by buf item,
      buf items will not be released in xfs_buf_delwri_cancel(), it's not easy
      to solve.
      
      If the filesystem has been shut down, then delwri list submission will
      error out all buffers on the list via IO submission/completion and do
      all the correct cleanup automatically. So shutting down the filesystem
      could prevents buffers in the bufffer_list from being written to disk.
      
      Fixes: 50d5c8d8 ("xfs: check LSN ordering for v5 superblocks during recovery")
      Signed-off-by: default avatarLong Li <leo.lilong@huawei.com>
      Reviewed-by: default avatar"Darrick J. Wong" <djwong@kernel.org>
      Signed-off-by: default avatarChandan Babu R <chandanbabu@kernel.org>
      e4c3b72a
    • Shrikanth Hegde's avatar
      xfs: remove duplicate ifdefs · 0164defd
      Shrikanth Hegde authored
      when a ifdef is used in the below manner, second one could be considered as
      duplicate.
      
      ifdef DEFINE_A
      ...code block...
      ifdef DEFINE_A
      ...code block...
      endif
      ...code block...
      endif
      
      In the xfs code two such patterns were seen. Hence removing these ifdefs.
      No functional change is intended here. It only aims to improve code
      readability.
      Reviewed-by: default avatar"Darrick J. Wong" <djwong@kernel.org>
      Signed-off-by: default avatarShrikanth Hegde <sshegde@linux.ibm.com>
      Signed-off-by: default avatarChandan Babu R <chandanbabu@kernel.org>
      0164defd
    • Darrick J. Wong's avatar
      xfs: disable sparse inode chunk alignment check when there is no alignment · 1149314a
      Darrick J. Wong authored
      While testing a 64k-blocksize filesystem, I noticed that xfs/709 fails
      to rebuild the inode btree with a bunch of "Corruption remains"
      messages.  It turns out that when the inode chunk size is smaller than a
      single filesystem block, no block alignments constraints are necessary
      for inode chunk allocations, and sb_spino_align is zero.  Hence we can
      skip the check.
      
      Fixes: dbfbf3bd ("xfs: repair inode btrees")
      Signed-off-by: default avatar"Darrick J. Wong" <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarChandan Babu R <chandanbabu@kernel.org>
      1149314a
  5. 13 Feb, 2024 12 commits