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  1. 09 12月, 2010 3 次提交
    • N
      md: fix possible deadlock in handling flush requests. · a035fc3e
      由 NeilBrown 提交于 
      As recorded in
    https://bugzilla.kernel.org/show_bug.cgi?id=24012

it is possible for a flush request through md to hang.  This is due to
an interaction between the recursion avoidance in
generic_make_request, the insistence in md of only having one flush
active at a time, and the possibility of dm (or md) submitting two
flush requests to a device from the one generic_make_request.

If a generic_make_request call into dm causes two flush requests to be
queued (as happens if the dm table has two targets - they get one
each), these two will be queued inside generic_make_request.

Assume they are for the same md device.
The first is processed and causes 1 or more flush requests to be sent
to lower devices.  These get queued within generic_make_request too.
Then the second flush to the md device gets handled and it blocks
waiting for the first flush to complete.  But it won't complete until
the two lower-device requests complete, and they haven't even been
submitted yet as they are on the generic_make_request queue.

The deadlock can be broken by using a separate thread to submit the
requests to lower devices.  md has such a thread readily available:
md_wq.

So use it to submit these requests.
Reported-by: NGiacomo Catenazzi <cate@cateee.net>
Tested-by: NGiacomo Catenazzi <cate@cateee.net>
Signed-off-by: NNeilBrown <neilb@suse.de>
      a035fc3e
    • N
      md: move code in to submit_flushes. · a7a07e69
      由 NeilBrown 提交于 
      submit_flushes is called from exactly one place.
Move the code that is before and after that call into
submit_flushes.

This has not functional change, but will make the next patch
smaller and easier to follow.
Signed-off-by: NNeilBrown <neilb@suse.de>
      a7a07e69
    • N
      md: remove handling of flush_pending in md_submit_flush_data · 2b74e12e
      由 NeilBrown 提交于 
      None of the functions called between setting flush_pending to 1, and
atomic_dec_and_test can change flush_pending, or will anything
running in any other thread (as ->flush_bio is not NULL).  So the
atomic_dec_and_test will always succeed.
So remove the atomic_sec and the atomic_dec_and_test.
Signed-off-by: NNeilBrown <neilb@suse.de>
      2b74e12e
  3. 24 11月, 2010 3 次提交
    • D
      md: Call blk_queue_flush() to establish flush/fua support · be20e6c6
      由 Darrick J. Wong 提交于 
      Before 2.6.37, the md layer had a mechanism for catching I/Os with the
barrier flag set, and translating the barrier into barriers for all
the underlying devices.  With 2.6.37, I/O barriers have become plain
old flushes, and the md code was updated to reflect this.  However,
one piece was left out -- the md layer does not tell the block layer
that it supports flushes or FUA access at all, which results in md
silently dropping flush requests.

Since the support already seems there, just add this one piece of
bookkeeping.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
      be20e6c6
    • N
      md/raid1: really fix recovery looping when single good device fails. · 8f9e0ee3
      由 NeilBrown 提交于 
      Commit 4044ba58 supposedly fixed a
problem where if a raid1 with just one good device gets a read-error
during recovery, the recovery would abort and immediately restart in
an infinite loop.

However it depended on raid1_remove_disk removing the spare device
from the array.  But that does not happen in this case.  So add a test
so that in the 'recovery_disabled' case, the device will be removed.

This suitable for any kernel since 2.6.29 which is when
recovery_disabled was introduced.

Cc: stable@kernel.org
Reported-by: NSebastian Färber <faerber@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
      8f9e0ee3
    • J
      md: fix return value of rdev_size_change() · c26a44ed
      由 Justin Maggard 提交于 
      When trying to grow an array by enlarging component devices,
rdev_size_store() expects the return value of rdev_size_change() to be
in sectors, but the actual value is returned in KBs.

This functionality was broken by commit
     dd8ac336
so this patch is suitable for any kernel since 2.6.30.

Cc: stable@kernel.org
Signed-off-by: NJustin Maggard <jmaggard10@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
      c26a44ed
  5. 22 11月, 2010 1 次提交
  7. 20 11月, 2010 13 次提交
  9. 19 11月, 2010 20 次提交