Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
接近 2 年 前同步成功

通知 170
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 19 8月, 2014 2 次提交
    • N
      md/raid10: Fix memory leak when raid10 reshape completes. · b3968552
      由 NeilBrown 提交于 
      When a raid10 commences a resync/recovery/reshape it allocates
some buffer space.
When a resync/recovery completes the buffer space is freed.  But not
when the reshape completes.
This can result in a small memory leak.

There is a subtle side-effect of this bug.  When a RAID10 is reshaped
to a larger array (more devices), the reshape is immediately followed
by a "resync" of the new space.  This "resync" will use the buffer
space which was allocated for "reshape".  This can cause problems
including a "BUG" in the SCSI layer.  So this is suitable for -stable.

Cc: stable@vger.kernel.org (v3.5+)
Fixes: 3ea7daa5Signed-off-by: NNeilBrown <neilb@suse.de>
      b3968552
    • N
      md/raid10: fix memory leak when reshaping a RAID10. · ce0b0a46
      由 NeilBrown 提交于 
      raid10 reshape clears unwanted bits from a bio->bi_flags using
a method which, while clumsy, worked until 3.10 when BIO_OWNS_VEC
was added.
Since then it clears that bit but shouldn't.  This results in a
memory leak.

So change to used the approved method of clearing unwanted bits.

As this causes a memory leak which can consume all of memory
the fix is suitable for -stable.

Fixes: a38352e0
Cc: stable@vger.kernel.org (v3.10+)
Reported-by: mdraid.pkoch@dfgh.net (Peter Koch)
Signed-off-by: NNeilBrown <neilb@suse.de>
      ce0b0a46
  3. 18 8月, 2014 2 次提交
    • N
      md/raid6: avoid data corruption during recovery of double-degraded RAID6 · 9c4bdf69
      由 NeilBrown 提交于 
      During recovery of a double-degraded RAID6 it is possible for
some blocks not to be recovered properly, leading to corruption.

If a write happens to one block in a stripe that would be written to a
missing device, and at the same time that stripe is recovering data
to the other missing device, then that recovered data may not be written.

This patch skips, in the double-degraded case, an optimisation that is
only safe for single-degraded arrays.

Bug was introduced in 2.6.32 and fix is suitable for any kernel since
then.  In an older kernel with separate handle_stripe5() and
handle_stripe6() functions the patch must change handle_stripe6().

Cc: stable@vger.kernel.org (2.6.32+)
Fixes: 6c0069c0
Cc: Yuri Tikhonov <yur@emcraft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: N"Manibalan P" <pmanibalan@amiindia.co.in>
Tested-by: N"Manibalan P" <pmanibalan@amiindia.co.in>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1090423Signed-off-by: NNeilBrown <neilb@suse.de>
Acked-by: NDan Williams <dan.j.williams@intel.com>
      9c4bdf69
    • N
      md/raid5: avoid livelock caused by non-aligned writes. · a40687ff
      由 NeilBrown 提交于 
      If a stripe in a raid6 array received a write to each data block while
the array is degraded, and if any of these writes to a missing device
are not page-aligned, then a live-lock happens.

In this case the P and Q blocks need to be read so that the part of
the missing block which is *not* being updated by the write can be
constructed.  Due to a logic error, these blocks are not loaded, so
the update cannot proceed and the stripe is 'handled' repeatedly in an
infinite loop.

This bug is unlikely as most writes are page aligned.  However as it
can lead to a livelock it is suitable for -stable.  It was introduced
in 3.16.

Cc: stable@vger.kernel.org (v3.16)
Fixed: 67f45548Signed-off-by: NNeilBrown <neilb@suse.de>
      a40687ff
  5. 11 8月, 2014 1 次提交
    • J
      dm table: propagate QUEUE_FLAG_NO_SG_MERGE · 200612ec
      由 Jeff Moyer 提交于 
      Commit 05f1dd53 ("block: add queue flag for disabling SG merging")
introduced a new queue flag: QUEUE_FLAG_NO_SG_MERGE.  This gets set by
default in blk_mq_init_queue for mq-enabled devices.  The effect of
the flag is to bypass the SG segment merging.  Instead, the
bio->bi_vcnt is used as the number of hardware segments.

With a device mapper target on top of a device with
QUEUE_FLAG_NO_SG_MERGE set, we can end up sending down more segments
than a driver is prepared to handle.  I ran into this when backporting
the virtio_blk mq support.  It triggerred this BUG_ON, in
virtio_queue_rq:

        BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);

The queue's max is set here:
        blk_queue_max_segments(q, vblk->sg_elems-2);

Basically, what happens is that a bio is built up for the dm device
(which does not have the QUEUE_FLAG_NO_SG_MERGE flag set) using
bio_add_page.  That path will call into __blk_recalc_rq_segments, so
what you end up with is bi_phys_segments being much smaller than bi_vcnt
(and bi_vcnt grows beyond the maximum sg elements).  Then, when the bio
is submitted, it gets cloned.  When the cloned bio is submitted, it will
end up in blk_recount_segments, here:

        if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags))
                bio->bi_phys_segments = bio->bi_vcnt;

and now we've set bio->bi_phys_segments to a number that is beyond what
was registered as queue_max_segments by the driver.

The right way to fix this is to propagate the queue flag up the stack.

The rules for propagating the flag are simple:
- if the flag is set for any underlying device, it must be set for the
  upper device
- consequently, if the flag is not set for any underlying device, it
  should not be set for the upper device.
Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.16+
      200612ec
  7. 08 8月, 2014 3 次提交
  9. 05 8月, 2014 22 次提交
  11. 02 8月, 2014 10 次提交