Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
dm mpath: take m->lock spinlock when testing QUEUE_IF_NO_PATH
Fix multipath_end_io, multipath_end_io_bio and multipath_busy to take
m->lock while testing if MPATHF_QUEUE_IF_NO_PATH bit is set. These are
all slow-path cases when no paths are available so extra locking isn't a
performance hit. Correctness matters most.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+34
-18
+34
-18
drivers/md/dm-mpath.c
+34
-18
drivers/md/dm-mpath.c
···
1621
1621
if (pgpath)
1622
1622
fail_path(pgpath);
1623
1623
1624
-
if (atomic_read(&m->nr_valid_paths) == 0 &&
1625
-
!must_push_back_rq(m)) {
1626
-
if (error == BLK_STS_IOERR)
1627
-
dm_report_EIO(m);
1628
-
/* complete with the original error */
1629
-
r = DM_ENDIO_DONE;
1624
+
if (!atomic_read(&m->nr_valid_paths)) {
1625
+
unsigned long flags;
1626
+
spin_lock_irqsave(&m->lock, flags);
1627
+
if (!must_push_back_rq(m)) {
1628
+
if (error == BLK_STS_IOERR)
1629
+
dm_report_EIO(m);
1630
+
/* complete with the original error */
1631
+
r = DM_ENDIO_DONE;
1632
+
}
1633
+
spin_unlock_irqrestore(&m->lock, flags);
1630
1634
}
1631
1635
}
1632
1636
···
1660
1656
if (pgpath)
1661
1657
fail_path(pgpath);
1662
1658
1663
-
if (atomic_read(&m->nr_valid_paths) == 0 &&
1664
-
!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
1665
-
if (__must_push_back(m)) {
1666
-
r = DM_ENDIO_REQUEUE;
1667
-
} else {
1668
-
dm_report_EIO(m);
1669
-
*error = BLK_STS_IOERR;
1659
+
if (!atomic_read(&m->nr_valid_paths)) {
1660
+
spin_lock_irqsave(&m->lock, flags);
1661
+
if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
1662
+
if (__must_push_back(m)) {
1663
+
r = DM_ENDIO_REQUEUE;
1664
+
} else {
1665
+
dm_report_EIO(m);
1666
+
*error = BLK_STS_IOERR;
1667
+
}
1668
+
spin_unlock_irqrestore(&m->lock, flags);
1669
+
goto done;
1670
1670
}
1671
-
goto done;
1671
+
spin_unlock_irqrestore(&m->lock, flags);
1672
1672
}
1673
1673
1674
1674
spin_lock_irqsave(&m->lock, flags);
···
1970
1962
}
1971
1963
} else {
1972
1964
/* No path is available */
1965
+
r = -EIO;
1966
+
spin_lock_irqsave(&m->lock, flags);
1973
1967
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
1974
1968
r = -ENOTCONN;
1975
-
else
1976
-
r = -EIO;
1969
+
spin_unlock_irqrestore(&m->lock, flags);
1977
1970
}
1978
1971
1979
1972
if (r == -ENOTCONN) {
···
2045
2036
return true;
2046
2037
2047
2038
/* no paths available, for blk-mq: rely on IO mapping to delay requeue */
2048
-
if (!atomic_read(&m->nr_valid_paths) && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
2049
-
return (m->queue_mode != DM_TYPE_REQUEST_BASED);
2039
+
if (!atomic_read(&m->nr_valid_paths)) {
2040
+
unsigned long flags;
2041
+
spin_lock_irqsave(&m->lock, flags);
2042
+
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
2043
+
spin_unlock_irqrestore(&m->lock, flags);
2044
+
return (m->queue_mode != DM_TYPE_REQUEST_BASED);
2045
+
}
2046
+
spin_unlock_irqrestore(&m->lock, flags);
2047
+
}
2050
2048
2051
2049
/* Guess which priority_group will be used at next mapping time */
2052
2050
pg = READ_ONCE(m->current_pg);