• Dave Chinner's avatar
    xfs: quotacheck leaves dquot buffers without verifiers · 5fd364fe
    Dave Chinner authored
    When running xfs/305, I noticed that quotacheck was flushing dquot
    buffers that did not have the xfs_dquot_buf_ops verifiers attached:
    
    XFS (vdb): _xfs_buf_ioapply: no ops on block 0x1dc8/0x1dc8
    ffff880052489000: 44 51 01 04 00 00 65 b8 00 00 00 00 00 00 00 00  DQ....e.........
    ffff880052489010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    ffff880052489020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    ffff880052489030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    CPU: 1 PID: 2376 Comm: mount Not tainted 3.16.0-rc2-dgc+ #306
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
     ffff88006fe38000 ffff88004a0ffae8 ffffffff81cf1cca 0000000000000001
     ffff88004a0ffb88 ffffffff814d50ca 000010004a0ffc70 0000000000000000
     ffff88006be56dc4 0000000000000021 0000000000001dc8 ffff88007c773d80
    Call Trace:
     [<ffffffff81cf1cca>] dump_stack+0x45/0x56
     [<ffffffff814d50ca>] _xfs_buf_ioapply+0x3ca/0x3d0
     [<ffffffff810db520>] ? wake_up_state+0x20/0x20
     [<ffffffff814d51f5>] ? xfs_bdstrat_cb+0x55/0xb0
     [<ffffffff814d513b>] xfs_buf_iorequest+0x6b/0xd0
     [<ffffffff814d51f5>] xfs_bdstrat_cb+0x55/0xb0
     [<ffffffff814d53ab>] __xfs_buf_delwri_submit+0x15b/0x220
     [<ffffffff814d6040>] ? xfs_buf_delwri_submit+0x30/0x90
     [<ffffffff814d6040>] xfs_buf_delwri_submit+0x30/0x90
     [<ffffffff8150f89d>] xfs_qm_quotacheck+0x17d/0x3c0
     [<ffffffff81510591>] xfs_qm_mount_quotas+0x151/0x1e0
     [<ffffffff814ed01c>] xfs_mountfs+0x56c/0x7d0
     [<ffffffff814f0f12>] xfs_fs_fill_super+0x2c2/0x340
     [<ffffffff811c9fe4>] mount_bdev+0x194/0x1d0
     [<ffffffff814f0c50>] ? xfs_finish_flags+0x170/0x170
     [<ffffffff814ef0f5>] xfs_fs_mount+0x15/0x20
     [<ffffffff811ca8c9>] mount_fs+0x39/0x1b0
     [<ffffffff811e4d67>] vfs_kern_mount+0x67/0x120
     [<ffffffff811e757e>] do_mount+0x23e/0xad0
     [<ffffffff8117abde>] ? __get_free_pages+0xe/0x50
     [<ffffffff811e71e6>] ? copy_mount_options+0x36/0x150
     [<ffffffff811e8103>] SyS_mount+0x83/0xc0
     [<ffffffff81cfd40b>] tracesys+0xdd/0xe2
    
    This was caused by dquot buffer readahead not attaching a verifier
    structure to the buffer when readahead was issued, resulting in the
    followup read of the buffer finding a valid buffer and so not
    attaching new verifiers to the buffer as part of the read.
    
    Also, when a verifier failure occurs, we then read the buffer
    without verifiers. Attach the verifiers manually after this read so
    that if the buffer is then written it will be verified that the
    corruption has been repaired.
    
    Further, when flushing a dquot we don't ask for a verifier when
    reading in the dquot buffer the dquot belongs to. Most of the time
    this isn't an issue because the buffer is still cached, but when it
    is not cached it will result in writing the dquot buffer without
    having the verfier attached.
    Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
    Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    5fd364fe
xfs_qm.c 47.4 KB