linux-stable.git/drivers/md, branch v3.16.35 Linux kernel stable tree md: multipath: don't hardcopy bio in .make_request path 2016-04-30T22:06:00+00:00 Ming Lei ming.lei@canonical.com 2016-03-12T01:29:40+00:00 e29d122d063662e2e2eb838ad28c82492361e154 commit fafcde3ac1a418688a734365203a12483b83907a upstream. Inside multipath_make_request(), multipath maps the incoming bio into low level device's bio, but it is totally wrong to copy the bio into mapped bio via '*mapped_bio = *bio'. For example, .__bi_remaining is kept in the copy, especially if the incoming bio is chained to via bio splitting, so .bi_end_io can't be called for the mapped bio at all in the completing path in this kind of situation. This patch fixes the issue by using clone style. Reported-and-tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit fafcde3ac1a418688a734365203a12483b83907a upstream.

Inside multipath_make_request(), multipath maps the incoming
bio into low level device's bio, but it is totally wrong to
copy the bio into mapped bio via '*mapped_bio = *bio'. For
example, .__bi_remaining is kept in the copy, especially if
the incoming bio is chained to via bio splitting, so .bi_end_io
can't be called for the mapped bio at all in the completing path
in this kind of situation.

This patch fixes the issue by using clone style.

Reported-and-tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
bcache: fix cache_set_flush() NULL pointer dereference on OOM 2016-04-30T22:05:56+00:00 Eric Wheeler git@linux.ewheeler.net 2016-03-07T23:17:50+00:00 456aee7e1f2bc28775a13abd3f6395aae49cf9b4 commit f8b11260a445169989d01df75d35af0f56178f95 upstream. When bch_cache_set_alloc() fails to kzalloc the cache_set, the asyncronous closure handling tries to dereference a cache_set that hadn't yet been allocated inside of cache_set_flush() which is called by __cache_set_unregister() during cleanup. This appears to happen only during an OOM condition on bcache_register. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f8b11260a445169989d01df75d35af0f56178f95 upstream.

When bch_cache_set_alloc() fails to kzalloc the cache_set, the
asyncronous closure handling tries to dereference a cache_set that
hadn't yet been allocated inside of cache_set_flush() which is called
by __cache_set_unregister() during cleanup.  This appears to happen only
during an OOM condition on bcache_register.

Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
bcache: cleaned up error handling around register_cache() 2016-04-30T22:05:56+00:00 Eric Wheeler git@linux.ewheeler.net 2016-02-26T22:33:56+00:00 53285dd2311096a04631998323560f265c8f4296 commit 9b299728ed777428b3908ac72ace5f8f84b97789 upstream. Fix null pointer dereference by changing register_cache() to return an int instead of being void. This allows it to return -ENOMEM or -ENODEV and enables upper layers to handle the OOM case without NULL pointer issues. See this thread: http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3521 Fixes this error: gargamel:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/register bcache: register_cache() error opening sdh2: cannot allocate memory BUG: unable to handle kernel NULL pointer dereference at 00000000000009b8 IP: [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache] PGD 120dff067 PUD 1119a3067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: veth ip6table_filter ip6_tables (...) CPU: 4 PID: 3371 Comm: kworker/4:3 Not tainted 4.4.2-amd64-i915-volpreempt-20160213bc1 #3 Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013 Workqueue: events cache_set_flush [bcache] task: ffff88020d5dc280 ti: ffff88020b6f8000 task.ti: ffff88020b6f8000 RIP: 0010:[<ffffffffc05a7e8d>] [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache] Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Tested-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 9b299728ed777428b3908ac72ace5f8f84b97789 upstream.

Fix null pointer dereference by changing register_cache() to return an int
instead of being void.  This allows it to return -ENOMEM or -ENODEV and
enables upper layers to handle the OOM case without NULL pointer issues.

See this thread:
  http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3521

Fixes this error:
  gargamel:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/register

  bcache: register_cache() error opening sdh2: cannot allocate memory
  BUG: unable to handle kernel NULL pointer dereference at 00000000000009b8
  IP: [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache]
  PGD 120dff067 PUD 1119a3067 PMD 0
  Oops: 0000 [#1] SMP
  Modules linked in: veth ip6table_filter ip6_tables
  (...)
  CPU: 4 PID: 3371 Comm: kworker/4:3 Not tainted 4.4.2-amd64-i915-volpreempt-20160213bc1 #3
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  Workqueue: events cache_set_flush [bcache]
  task: ffff88020d5dc280 ti: ffff88020b6f8000 task.ti: ffff88020b6f8000
  RIP: 0010:[<ffffffffc05a7e8d>]  [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache]

Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
bcache: Fix more early shutdown bugs 2016-04-30T22:05:55+00:00 Kent Overstreet kmo@daterainc.com 2014-06-12T02:44:49+00:00 eebbc086adaef10e7cd91e1b13b4063a4d4756a2 commit d83353b319d47ef8cce82467da6a25c2d558253f upstream. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit d83353b319d47ef8cce82467da6a25c2d558253f upstream.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
md/raid5: Compare apples to apples (or sectors to sectors) 2016-04-30T22:05:51+00:00 Jes Sorensen Jes.Sorensen@redhat.com 2016-02-16T21:44:24+00:00 2af186e096d2ddbba05a742f588e2b1d1fcb5662 commit e7597e69dec59b65c5525db1626b9d34afdfa678 upstream. 'max_discard_sectors' is in sectors, while 'stripe' is in bytes. This fixes the problem where DISCARD would get disabled on some larger RAID5 configurations (6 or more drives in my testing), while it worked as expected with smaller configurations. Fixes: 620125f2bf8 ("MD: raid5 trim support") Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e7597e69dec59b65c5525db1626b9d34afdfa678 upstream.

'max_discard_sectors' is in sectors, while 'stripe' is in bytes.

This fixes the problem where DISCARD would get disabled on some larger
RAID5 configurations (6 or more drives in my testing), while it worked
as expected with smaller configurations.

Fixes: 620125f2bf8 ("MD: raid5 trim support")
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
bcache: add mutex lock for bch_is_open 2016-03-24T10:01:17+00:00 Jianjian Huo samuel.huo@gmail.com 2014-07-13T16:08:59+00:00 9541db7a989ae95b320013de227f2a132e6f0463 commit 789d21dbd9d8889e62c79ec19585fcc97e42ef07 upstream. Since bch_is_open will iterate linked list bch_cache_sets and uncached_devices, it needs bch_register_lock. Signed-off-by: Jianjian Huo <samuel.huo@gmail.com> Cc: Kamal Mostafa <kamal@canonical.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit 789d21dbd9d8889e62c79ec19585fcc97e42ef07 upstream.

Since bch_is_open will iterate linked list bch_cache_sets and
uncached_devices, it needs bch_register_lock.

Signed-off-by: Jianjian Huo <samuel.huo@gmail.com>
Cc: Kamal Mostafa <kamal@canonical.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
dm snapshot: fix hung bios when copy error occurs 2016-02-02T19:09:21+00:00 Mikulas Patocka mpatocka@redhat.com 2016-01-09T00:07:55+00:00 e33972a9b5e6a1ab92258308215044bb81e159a1 commit 385277bfb57faac44e92497104ba542cdd82d5fe upstream. When there is an error copying a chunk dm-snapshot can incorrectly hold associated bios indefinitely, resulting in hung IO. The function copy_callback sets pe->error if there was error copying the chunk, and then calls complete_exception. complete_exception calls pending_complete on error, otherwise it calls commit_exception with commit_callback (and commit_callback calls complete_exception). The persistent exception store (dm-snap-persistent.c) assumes that calls to prepare_exception and commit_exception are paired. persistent_prepare_exception increases ps->pending_count and persistent_commit_exception decreases it. If there is a copy error, persistent_prepare_exception is called but persistent_commit_exception is not. This results in the variable ps->pending_count never returning to zero and that causes some pending exceptions (and their associated bios) to be held forever. Fix this by unconditionally calling commit_exception regardless of whether the copy was successful. A new "valid" parameter is added to commit_exception -- when the copy fails this parameter is set to zero so that the chunk that failed to copy (and all following chunks) is not recorded in the snapshot store. Also, remove commit_callback now that it is merely a wrapper around pending_complete. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit 385277bfb57faac44e92497104ba542cdd82d5fe upstream.

When there is an error copying a chunk dm-snapshot can incorrectly hold
associated bios indefinitely, resulting in hung IO.

The function copy_callback sets pe->error if there was error copying the
chunk, and then calls complete_exception.  complete_exception calls
pending_complete on error, otherwise it calls commit_exception with
commit_callback (and commit_callback calls complete_exception).

The persistent exception store (dm-snap-persistent.c) assumes that calls
to prepare_exception and commit_exception are paired.
persistent_prepare_exception increases ps->pending_count and
persistent_commit_exception decreases it.

If there is a copy error, persistent_prepare_exception is called but
persistent_commit_exception is not.  This results in the variable
ps->pending_count never returning to zero and that causes some pending
exceptions (and their associated bios) to be held forever.

Fix this by unconditionally calling commit_exception regardless of
whether the copy was successful.  A new "valid" parameter is added to
commit_exception -- when the copy fails this parameter is set to zero so
that the chunk that failed to copy (and all following chunks) is not
recorded in the snapshot store.  Also, remove commit_callback now that
it is merely a wrapper around pending_complete.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
bcache: Change refill_dirty() to always scan entire disk if necessary 2016-02-02T19:09:12+00:00 Kent Overstreet kent.overstreet@gmail.com 2015-11-30T02:47:01+00:00 412d44066a0effc1bb761ba8da4336ba45f84c8e commit 627ccd20b4ad3ba836472468208e2ac4dfadbf03 upstream. Previously, it would only scan the entire disk if it was starting from the very start of the disk - i.e. if the previous scan got to the end. This was broken by refill_full_stripes(), which updates last_scanned so that refill_dirty was never triggering the searched_from_start path. But if we change refill_dirty() to always scan the entire disk if necessary, regardless of what last_scanned was, the code gets cleaner and we fix that bug too. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit 627ccd20b4ad3ba836472468208e2ac4dfadbf03 upstream.

Previously, it would only scan the entire disk if it was starting from
the very start of the disk - i.e. if the previous scan got to the end.

This was broken by refill_full_stripes(), which updates last_scanned so
that refill_dirty was never triggering the searched_from_start path.

But if we change refill_dirty() to always scan the entire disk if
necessary, regardless of what last_scanned was, the code gets cleaner
and we fix that bug too.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
bcache: prevent crash on changing writeback_running 2016-02-02T19:09:12+00:00 Stefan Bader stefan.bader@canonical.com 2015-11-30T02:44:49+00:00 79eeb71cb888fe9cd2c5fde1e31ad4fe545b5fc1 commit 8d16ce540c94c9d366eb36fc91b7154d92d6397b upstream. Added a safeguard in the shutdown case. At least while not being attached it is also possible to trigger a kernel bug by writing into writeback_running. This change adds the same check before trying to wake up the thread for that case. Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit 8d16ce540c94c9d366eb36fc91b7154d92d6397b upstream.

Added a safeguard in the shutdown case. At least while not being
attached it is also possible to trigger a kernel bug by writing into
writeback_running. This change  adds the same check before trying to
wake up the thread for that case.

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
bcache: allows use of register in udev to avoid "device_busy" error. 2016-02-02T19:09:11+00:00 Gabriel de Perthuis g2p.code@gmail.com 2015-11-30T02:40:23+00:00 6468bfb9bcd2db7697612afc854132b7554fb465 commit d7076f21629f8f329bca4a44dc408d94670f49e2 upstream. Allows to use register, not register_quiet in udev to avoid "device_busy" error. The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis <g2p.code@gmail.com> does not unlock the mutex and hangs the kernel. See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion. Cc: Denis Bychkov <manover@gmail.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Gabriel de Perthuis <g2p.code@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit d7076f21629f8f329bca4a44dc408d94670f49e2 upstream.

Allows to use register, not register_quiet in udev to avoid "device_busy" error.
The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis
<g2p.code@gmail.com> does not unlock the mutex and hangs the kernel.

See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion.

Cc: Denis Bychkov <manover@gmail.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Eric Wheeler <bcache@linux.ewheeler.net>
Cc: Gabriel de Perthuis <g2p.code@gmail.com>

Signed-off-by: Jens Axboe <axboe@fb.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>