linux-stable.git/drivers/md, branch v3.4.112 Linux kernel stable tree raid1: include bio_end_io_list in nr_queued to prevent freeze_array hang 2016-04-27T10:55:30+00:00 Nate Dailey nate.dailey@stratus.com 2016-02-29T15:43:58+00:00 9237baa5c61ef9e11d8a71d02d73b53d8a2b7d01 commit ccfc7bf1f09d6190ef86693ddc761d5fe3fa47cb upstream. If raid1d is handling a mix of read and write errors, handle_read_error's call to freeze_array can get stuck. This can happen because, though the bio_end_io_list is initially drained, writes can be added to it via handle_write_finished as the retry_list is processed. These writes contribute to nr_pending but are not included in nr_queued. If a later entry on the retry_list triggers a call to handle_read_error, freeze array hangs waiting for nr_pending == nr_queued+extra. The writes on the bio_end_io_list aren't included in nr_queued so the condition will never be satisfied. To prevent the hang, include bio_end_io_list writes in nr_queued. There's probably a better way to handle decrementing nr_queued, but this seemed like the safest way to avoid breaking surrounding code. I'm happy to supply the script I used to repro this hang. Fixes: 55ce74d4bfe1b(md/raid1: ensure device failure recorded before write request returns.) Signed-off-by: Nate Dailey <nate.dailey@stratus.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit ccfc7bf1f09d6190ef86693ddc761d5fe3fa47cb upstream.

If raid1d is handling a mix of read and write errors, handle_read_error's
call to freeze_array can get stuck.

This can happen because, though the bio_end_io_list is initially drained,
writes can be added to it via handle_write_finished as the retry_list
is processed. These writes contribute to nr_pending but are not included
in nr_queued.

If a later entry on the retry_list triggers a call to handle_read_error,
freeze array hangs waiting for nr_pending == nr_queued+extra. The writes
on the bio_end_io_list aren't included in nr_queued so the condition will
never be satisfied.

To prevent the hang, include bio_end_io_list writes in nr_queued.

There's probably a better way to handle decrementing nr_queued, but this
seemed like the safest way to avoid breaking surrounding code.

I'm happy to supply the script I used to repro this hang.

Fixes: 55ce74d4bfe1b(md/raid1: ensure device failure recorded before write request returns.)
Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
dm btree: fix leak of bufio-backed block in btree_split_beneath error path 2016-04-27T10:55:29+00:00 Mike Snitzer snitzer@redhat.com 2015-10-22T14:56:40+00:00 ede7386c3e8605a23c9ea89530894ce074397aa6 commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream. btree_split_beneath()'s error path had an outstanding FIXME that speaks directly to the potential for _not_ cleaning up a previously allocated bufio-backed block. Fix this by releasing the previously allocated bufio block using unlock_block(). Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream.

btree_split_beneath()'s error path had an outstanding FIXME that speaks
directly to the potential for _not_ cleaning up a previously allocated
bufio-backed block.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
md/raid1: don't clear bitmap bit when bad-block-list write fails. 2016-04-27T10:55:22+00:00 NeilBrown neilb@suse.com 2015-10-24T05:02:16+00:00 6126604d3fafa03231cadbdbef2d8cd5faa00085 commit bd8688a199b864944bf62eebed0ca13b46249453 upstream. When a write fails and a bad-block-list is present, we can update the bad-block-list instead of writing the data. If this succeeds then it is OK clear the relevant bitmap-bit as no further 'sync' of the block is needed. However if writing the bad-block-list fails then we need to treat the write as failed and particularly must not clear the bitmap bit. Otherwise the device can be re-added (after any hardware connection issues are resolved) and because the relevant bit in the bitmap is clear, that block will not be resynced. This leads to data corruption. We already delay the final bio_endio() on the write until the bad-block-list is written so that when the write returns: either that data is safe, the bad-block record is safe, or the fact that the device is faulty is safe. However we *don't* delay the clearing of the bitmap, so the bitmap bit can be recorded as cleared before we know if the bad-block-list was written safely. So: delay that until the write really is safe. i.e. move the call to close_write() until just before calling bio_endio(), and recheck the 'is array degraded' status before making that call. This bug goes back to v3.1 when bad-block-lists were introduced, though it only affects arrays created with mdadm-3.3 or later as only those have bad-block lists. Backports will require at least Commit: 55ce74d4bfe1 ("md/raid1: ensure device failure recorded before write request returns.") as well. I'll send that to 'stable' separately. Note that of the two tests of R1BIO_WriteError that this patch adds, the first is certain to fail and the second is certain to succeed. However doing it this way makes the patch more obviously correct. I will tidy the code up in a future merge window. Reported-and-tested-by: Nate Dailey <nate.dailey@stratus.com> Cc: Jes Sorensen <Jes.Sorensen@redhat.com> Fixes: cd5ff9a16f08 ("md/raid1: Handle write errors by updating badblock log.") Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit bd8688a199b864944bf62eebed0ca13b46249453 upstream.

When a write fails and a bad-block-list is present, we can
update the bad-block-list instead of writing the data.  If
this succeeds then it is OK clear the relevant bitmap-bit as
no further 'sync' of the block is needed.

However if writing the bad-block-list fails then we need to
treat the write as failed and particularly must not clear
the bitmap bit.  Otherwise the device can be re-added (after
any hardware connection issues are resolved) and because the
relevant bit in the bitmap is clear, that block will not be
resynced.  This leads to data corruption.

We already delay the final bio_endio() on the write until
the bad-block-list is written so that when the write
returns: either that data is safe, the bad-block record is
safe, or the fact that the device is faulty is safe.
However we *don't* delay the clearing of the bitmap, so the
bitmap bit can be recorded as cleared before we know if the
bad-block-list was written safely.

So: delay that until the write really is safe.
i.e. move the call to close_write() until just before
calling bio_endio(), and recheck the 'is array degraded'
status before making that call.

This bug goes back to v3.1 when bad-block-lists were
introduced, though it only affects arrays created with
mdadm-3.3 or later as only those have bad-block lists.

Backports will require at least
Commit: 55ce74d4bfe1 ("md/raid1: ensure device failure recorded before write request returns.")
as well.  I'll send that to 'stable' separately.

Note that of the two tests of R1BIO_WriteError that this
patch adds, the first is certain to fail and the second is
certain to succeed.  However doing it this way makes the
patch more obviously correct.  I will tidy the code up in a
future merge window.

Reported-and-tested-by: Nate Dailey <nate.dailey@stratus.com>
Cc: Jes Sorensen <Jes.Sorensen@redhat.com>
Fixes: cd5ff9a16f08 ("md/raid1:  Handle write errors by updating badblock log.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
md/raid1: ensure device failure recorded before write request returns. 2016-04-27T10:55:21+00:00 NeilBrown neilb@suse.com 2015-08-14T01:11:10+00:00 f6b1d7cb981875eb995795eb9987be6d7825099e commit 55ce74d4bfe1b9444436264c637f39a152d1e5ac upstream. When a write to one of the legs of a RAID1 fails, the failure is recorded in the metadata of the other leg(s) so that after a restart the data on the failed drive wont be trusted even if that drive seems to be working again (maybe a cable was unplugged). Similarly when we record a bad-block in response to a write failure, we must not let the write complete until the bad-block update is safe. Currently there is no interlock between the write request completing and the metadata update. So it is possible that the write will complete, the app will confirm success in some way, and then the machine will crash before the metadata update completes. This is an extremely small hole for a racy to fit in, but it is theoretically possible and so should be closed. So: - set MD_CHANGE_PENDING when requesting a metadata update for a failed device, so we can know with certainty when it completes - queue requests that experienced an error on a new queue which is only processed after the metadata update completes - call raid_end_bio_io() on bios in that queue when the time comes. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 55ce74d4bfe1b9444436264c637f39a152d1e5ac upstream.

When a write to one of the legs of a RAID1 fails, the failure is
recorded in the metadata of the other leg(s) so that after a restart
the data on the failed drive wont be trusted even if that drive seems
to be working again  (maybe a cable was unplugged).

Similarly when we record a bad-block in response to a write failure,
we must not let the write complete until the bad-block update is safe.

Currently there is no interlock between the write request completing
and the metadata update.  So it is possible that the write will
complete, the app will confirm success in some way, and then the
machine will crash before the metadata update completes.

This is an extremely small hole for a racy to fit in, but it is
theoretically possible and so should be closed.

So:
 - set MD_CHANGE_PENDING when requesting a metadata update for a
   failed device, so we can know with certainty when it completes
 - queue requests that experienced an error on a new queue which
   is only processed after the metadata update completes
 - call raid_end_bio_io() on bios in that queue when the time comes.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
md/raid10: don't clear bitmap bit when bad-block-list write fails. 2016-04-27T10:55:21+00:00 NeilBrown neilb@suse.com 2015-10-24T05:23:48+00:00 0570dab32ddd0f0c7db5ccd025a1597fffb9e464 commit c340702ca26a628832fade4f133d8160a55c29cc upstream. When a write fails and a bad-block-list is present, we can update the bad-block-list instead of writing the data. If this succeeds then it is OK clear the relevant bitmap-bit as no further 'sync' of the block is needed. However if writing the bad-block-list fails then we need to treat the write as failed and particularly must not clear the bitmap bit. Otherwise the device can be re-added (after any hardware connection issues are resolved) and because the relevant bit in the bitmap is clear, that block will not be resynced. This leads to data corruption. We already delay the final bio_endio() on the write until the bad-block-list is written so that when the write returns: either that data is safe, the bad-block record is safe, or the fact that the device is faulty is safe. However we *don't* delay the clearing of the bitmap, so the bitmap bit can be recorded as cleared before we know if the bad-block-list was written safely. So: delay that until the write really is safe. i.e. move the call to close_write() until just before calling bio_endio(), and recheck the 'is array degraded' status before making that call. This bug goes back to v3.1 when bad-block-lists were introduced, though it only affects arrays created with mdadm-3.3 or later as only those have bad-block lists. Backports will require at least Commit: 95af587e95aa ("md/raid10: ensure device failure recorded before write request returns.") as well. I'll send that to 'stable' separately. Note that of the two tests of R10BIO_WriteError that this patch adds, the first is certain to fail and the second is certain to succeed. However doing it this way makes the patch more obviously correct. I will tidy the code up in a future merge window. Reported-by: Nate Dailey <nate.dailey@stratus.com> Fixes: bd870a16c594 ("md/raid10: Handle write errors by updating badblock log.") Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit c340702ca26a628832fade4f133d8160a55c29cc upstream.

When a write fails and a bad-block-list is present, we can
update the bad-block-list instead of writing the data.  If
this succeeds then it is OK clear the relevant bitmap-bit as
no further 'sync' of the block is needed.

However if writing the bad-block-list fails then we need to
treat the write as failed and particularly must not clear
the bitmap bit.  Otherwise the device can be re-added (after
any hardware connection issues are resolved) and because the
relevant bit in the bitmap is clear, that block will not be
resynced.  This leads to data corruption.

We already delay the final bio_endio() on the write until
the bad-block-list is written so that when the write
returns: either that data is safe, the bad-block record is
safe, or the fact that the device is faulty is safe.
However we *don't* delay the clearing of the bitmap, so the
bitmap bit can be recorded as cleared before we know if the
bad-block-list was written safely.

So: delay that until the write really is safe.
i.e. move the call to close_write() until just before
calling bio_endio(), and recheck the 'is array degraded'
status before making that call.

This bug goes back to v3.1 when bad-block-lists were
introduced, though it only affects arrays created with
mdadm-3.3 or later as only those have bad-block lists.

Backports will require at least
Commit: 95af587e95aa ("md/raid10: ensure device failure recorded before write request returns.")
as well.  I'll send that to 'stable' separately.

Note that of the two tests of R10BIO_WriteError that this
patch adds, the first is certain to fail and the second is
certain to succeed.  However doing it this way makes the
patch more obviously correct.  I will tidy the code up in a
future merge window.

Reported-by: Nate Dailey <nate.dailey@stratus.com>
Fixes: bd870a16c594 ("md/raid10:  Handle write errors by updating badblock log.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
md/raid10: ensure device failure recorded before write request returns. 2016-04-27T10:55:21+00:00 NeilBrown neilb@suse.com 2015-08-14T01:26:17+00:00 43bf02bac43bd2697f9e20c0feee434ba6ebe9db commit 95af587e95aacb9cfda4a9641069a5244a540dc8 upstream. When a write to one of the legs of a RAID10 fails, the failure is recorded in the metadata of the other legs so that after a restart the data on the failed drive wont be trusted even if that drive seems to be working again (maybe a cable was unplugged). Currently there is no interlock between the write request completing and the metadata update. So it is possible that the write will complete, the app will confirm success in some way, and then the machine will crash before the metadata update completes. This is an extremely small hole for a racy to fit in, but it is theoretically possible and so should be closed. So: - set MD_CHANGE_PENDING when requesting a metadata update for a failed device, so we can know with certainty when it completes - queue requests that experienced an error on a new queue which is only processed after the metadata update completes - call raid_end_bio_io() on bios in that queue when the time comes. Signed-off-by: NeilBrown <neilb@suse.com> [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 95af587e95aacb9cfda4a9641069a5244a540dc8 upstream.

When a write to one of the legs of a RAID10 fails, the failure is
recorded in the metadata of the other legs so that after a restart
the data on the failed drive wont be trusted even if that drive seems
to be working again (maybe a cable was unplugged).

Currently there is no interlock between the write request completing
and the metadata update.  So it is possible that the write will
complete, the app will confirm success in some way, and then the
machine will crash before the metadata update completes.

This is an extremely small hole for a racy to fit in, but it is
theoretically possible and so should be closed.

So:
 - set MD_CHANGE_PENDING when requesting a metadata update for a
   failed device, so we can know with certainty when it completes
 - queue requests that experienced an error on a new queue which
   is only processed after the metadata update completes
 - call raid_end_bio_io() on bios in that queue when the time comes.

Signed-off-by: NeilBrown <neilb@suse.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
md/raid0: apply base queue limits *before* disk_stack_limits 2016-04-27T10:55:20+00:00 NeilBrown neilb@suse.com 2015-09-24T05:47:47+00:00 55555bf1c6f353b84a23e681f3b487152f730926 commit 66eefe5de11db1e0d8f2edc3880d50e7c36a9d43 upstream. Calling e.g. blk_queue_max_hw_sectors() after calls to disk_stack_limits() discards the settings determined by disk_stack_limits(). So we need to make those calls first. Fixes: 199dc6ed5179 ("md/raid0: update queue parameter in a safer location.") Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 66eefe5de11db1e0d8f2edc3880d50e7c36a9d43 upstream.

Calling e.g. blk_queue_max_hw_sectors() after calls to
disk_stack_limits() discards the settings determined by
disk_stack_limits().
So we need to make those calls first.

Fixes: 199dc6ed5179 ("md/raid0: update queue parameter in a safer location.")
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
scsi_dh: fix randconfig build error 2016-04-27T10:55:18+00:00 Christoph Hellwig hch@lst.de 2015-09-09T16:04:18+00:00 3cd0ee55312d9e53ac6966d071c48e218c3a2a53 commit 294ab783ad98066b87296db1311c7ba2a60206a5 upstream. It looks like the Kconfig check that was meant to fix this (commit fe9233fb6914a0eb20166c967e3020f7f0fba2c9 [SCSI] scsi_dh: fix kconfig related build errors) was actually reversed, but no-one noticed until the new set of patches which separated DM and SCSI_DH). Fixes: fe9233fb6914a0eb20166c967e3020f7f0fba2c9 Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 294ab783ad98066b87296db1311c7ba2a60206a5 upstream.

It looks like the Kconfig check that was meant to fix this (commit
fe9233fb6914a0eb20166c967e3020f7f0fba2c9 [SCSI] scsi_dh: fix kconfig related
build errors) was actually reversed, but no-one noticed until the new set of
patches which separated DM and SCSI_DH).

Fixes: fe9233fb6914a0eb20166c967e3020f7f0fba2c9
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
md/raid0: update queue parameter in a safer location. 2016-04-27T10:55:14+00:00 NeilBrown neilb@suse.com 2015-08-03T03:11:47+00:00 ec2890a5fd0febb6e27e4893f5f6ffbd4dfaf735 commit 199dc6ed5179251fa6158a461499c24bdd99c836 upstream. When a (e.g.) RAID5 array is reshaped to RAID0, the updating of queue parameters (e.g. max number of sectors per bio) is done in the wrong place. It should be part of ->run, but it is actually part of ->takeover. This means it happens before level_store() calls: blk_set_stacking_limits(&mddev->queue->limits); and so it ineffective. This can lead to errors from underlying devices. So move all the relevant settings out of create_stripe_zones() and into raid0_run(). As this can lead to a bug-on it is suitable for any -stable kernel which supports reshape to RAID0. So 2.6.35 or later. As the bug has been present for five years there is no urgency, so no need to rush into -stable. Fixes: 9af204cf720c ("md: Add support for Raid5->Raid0 and Raid10->Raid0 takeover") Reported-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> [lizf: Backported to 3.4: - adjust context - remove changes to discard and write-same features] Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 199dc6ed5179251fa6158a461499c24bdd99c836 upstream.

When a (e.g.) RAID5 array is reshaped to RAID0, the updating
of queue parameters (e.g. max number of sectors per bio) is
done in the wrong place.
It should be part of ->run, but it is actually part of ->takeover.
This means it happens before level_store() calls:

	blk_set_stacking_limits(&mddev->queue->limits);

and so it ineffective.  This can lead to errors from underlying
devices.

So move all the relevant settings out of create_stripe_zones()
and into raid0_run().

As this can lead to a bug-on it is suitable for any -stable
kernel which supports reshape to RAID0.  So 2.6.35 or later.
As the bug has been present for five years there is no urgency,
so no need to rush into -stable.

Fixes: 9af204cf720c ("md: Add support for Raid5->Raid0 and Raid10->Raid0 takeover")
Reported-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
[lizf: Backported to 3.4:
 - adjust context
 - remove changes to discard and write-same features]
Signed-off-by: Zefan Li <lizefan@huawei.com>
dm btree remove: fix a bug when rebalancing nodes after removal 2016-03-21T01:17:58+00:00 Joe Thornber ejt@redhat.com 2015-10-21T17:36:49+00:00 24fa51bde52b3671afa476c96d63bcf8a4e8a307 commit 2871c69e025e8bc507651d5a9cf81a8a7da9d24b upstream. Commit 4c7e309340ff ("dm btree remove: fix bug in redistribute3") wasn't a complete fix for redistribute3(). The redistribute3 function takes 3 btree nodes and shares out the entries evenly between them. If the three nodes in total contained (MAX_ENTRIES * 3) - 1 entries between them then this was erroneously getting rebalanced as (MAX_ENTRIES - 1) on the left and right, and (MAX_ENTRIES + 1) in the center. Fix this issue by being more careful about calculating the target number of entries for the left and right nodes. Unit tested in userspace using this program: https://github.com/jthornber/redistribute3-test/blob/master/redistribute3_t.c Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Zefan Li <lizefan@huawei.com> 
commit 2871c69e025e8bc507651d5a9cf81a8a7da9d24b upstream.

Commit 4c7e309340ff ("dm btree remove: fix bug in redistribute3") wasn't
a complete fix for redistribute3().

The redistribute3 function takes 3 btree nodes and shares out the entries
evenly between them.  If the three nodes in total contained
(MAX_ENTRIES * 3) - 1 entries between them then this was erroneously getting
rebalanced as (MAX_ENTRIES - 1) on the left and right, and (MAX_ENTRIES + 1) in
the center.

Fix this issue by being more careful about calculating the target number
of entries for the left and right nodes.

Unit tested in userspace using this program:
https://github.com/jthornber/redistribute3-test/blob/master/redistribute3_t.c

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>