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author | Brian Foster <bfoster@redhat.com> | 2016-05-18 10:56:41 +1000 |
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committer | Dave Chinner <david@fromorbit.com> | 2016-05-18 10:56:41 +1000 |
commit | 9bdd9bd69b826875531bb1b2efb6aeb8d70e6f72 (patch) | |
tree | 8cf9acecfa7280e4c3e43e116dc1f592665fa14b /fs/xfs/xfs_sysfs.c | |
parent | f55532a0c0b8bb6148f4e07853b876ef73bc69ca (diff) | |
download | linux-9bdd9bd69b826875531bb1b2efb6aeb8d70e6f72.tar.bz2 |
xfs: buffer ->bi_end_io function requires irq-safe lock
Reports have surfaced of a lockdep splat complaining about an
irq-safe -> irq-unsafe locking order in the xfs_buf_bio_end_io() bio
completion handler. This only occurs when I/O errors are present
because bp->b_lock is only acquired in this context to protect
setting an error on the buffer. The problem is that this lock can be
acquired with the (request_queue) q->queue_lock held. See
scsi_end_request() or ata_qc_schedule_eh(), for example.
Replace the locked test/set of b_io_error with a cmpxchg() call.
This eliminates the need for the lock and thus the lock ordering
problem goes away.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_sysfs.c')
0 files changed, 0 insertions, 0 deletions