Commit graph

3,697 commits

Author SHA1 Message Date
NeilBrown
18c45d9c8e md: flush ->event_work before stopping array.
commit ee5d004fd0 upstream.

The 'event_work' worker used by dm-raid may still be running
when the array is stopped.  This can result in an oops.

So flush the workqueue on which it is run after detaching
and before destroying the device.

Reported-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Fixes: 9d09e663d5 ("dm: raid456 basic support")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-29 19:26:14 +02:00
NeilBrown
ae286448cf md/raid10: always set reshape_safe when initializing reshape_position.
commit 299b0685e3 upstream.

'reshape_position' tracks where in the reshape we have reached.
'reshape_safe' tracks where in the reshape we have safely recorded
in the metadata.

These are compared to determine when to update the metadata.
So it is important that reshape_safe is initialised properly.
Currently it isn't.  When starting a reshape from the beginning
it usually has the correct value by luck.  But when reducing the
number of devices in a RAID10, it has the wrong value and this leads
to the metadata not being updated correctly.
This can lead to corruption if the reshape is not allowed to complete.

This patch is suitable for any -stable kernel which supports RAID10
reshape, which is 3.5 and later.

Fixes: 3ea7daa5d7 ("md/raid10: add reshape support")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-29 19:26:13 +02:00
NeilBrown
d7edf5fe97 md/raid5: don't let shrink_slab shrink too far.
commit 49895bcc7e upstream.

I have a report of drop_one_stripe() called from
raid5_cache_scan() apparently finding ->max_nr_stripes == 0.

This should not be allowed.

So add a test to keep max_nr_stripes above min_nr_stripes.

Also use a 'mask' rather than a 'mod' in drop_one_stripe
to ensure 'hash' is valid even if max_nr_stripes does reach zero.


Fixes: edbe83ab4c ("md/raid5: allow the stripe_cache to grow and shrink.")
Reported-by: Tomas Papan <tomas.papan@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-29 19:26:13 +02:00
NeilBrown
ed8b312450 md/raid5: avoid races when changing cache size.
commit 2d5b569b66 upstream.

Cache size can grow or shrink due to various pressures at
any time.  So when we resize the cache as part of a 'grow'
operation (i.e. change the size to allow more devices) we need
to blocks that automatic growing/shrinking.

So introduce a mutex.  auto grow/shrink uses mutex_trylock()
and just doesn't bother if there is a blockage.
Resizing the whole cache holds the mutex to ensure that
the correct number of new stripes is allocated.

This bug can result in some stripes not being freed when an
array is stopped.  This leads to the kmem_cache not being
freed and a subsequent array can try to use the same kmem_cache
and get confused.

Fixes: edbe83ab4c ("md/raid5: allow the stripe_cache to grow and shrink.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-29 19:26:13 +02:00
Joe Thornber
32d063ab01 dm thin metadata: delete btrees when releasing metadata snapshot
commit 7f518ad0a2 upstream.

The device details and mapping trees were just being decremented
before.  Now btree_del() is called to do a deep delete.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-13 09:07:40 -07:00
Mike Snitzer
8ce686edc5 dm: fix dm_merge_bvec regression on 32 bit systems
commit bd4aaf8f9b upstream.

A DM regression on 32 bit systems was reported against v4.2-rc3 here:
https://lkml.org/lkml/2015/7/29/401

Fix this by reverting both commit 1c220c69 ("dm: fix casting bug in
dm_merge_bvec()") and 148e51ba ("dm: improve documentation and code
clarity in dm_merge_bvec").  This combined revert is done to eliminate
the possibility of a partial revert in stable@ kernels.

In hindsight the correct fix, at the time 1c220c69 was applied to fix
the regression that 148e51ba introduced, should've been to simply revert
148e51ba.

Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Tested-by: Adam Williamson <awilliam@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16 20:52:23 -07:00
NeilBrown
24a9fa79d5 md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies
commit 423f04d63c upstream.

raid1_end_read_request() assumes that the In_sync bits are consistent
with the ->degaded count.
raid1_spare_active updates the In_sync bit before the ->degraded count
and so exposes an inconsistency, as does error()
So extend the spinlock in raid1_spare_active() and error() to hide those
inconsistencies.

This should probably be part of
  Commit: 34cab6f420 ("md/raid1: fix test for 'was read error from
  last working device'.")
as it addresses the same issue.  It fixes the same bug and should go
to -stable for same reasons.

Fixes: 76073054c9 ("md/raid1: clean up read_balance.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16 20:52:23 -07:00
Benjamin Randazzo
33afeac21b md: use kzalloc() when bitmap is disabled
commit b6878d9e03 upstream.

In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a
mdu_bitmap_file_t called "file".

5769         file = kmalloc(sizeof(*file), GFP_NOIO);
5770         if (!file)
5771                 return -ENOMEM;

This structure is copied to user space at the end of the function.

5786         if (err == 0 &&
5787             copy_to_user(arg, file, sizeof(*file)))
5788                 err = -EFAULT

But if bitmap is disabled only the first byte of "file" is initialized
with zero, so it's possible to read some bytes (up to 4095) of kernel
space memory from user space. This is an information leak.

5775         /* bitmap disabled, zero the first byte and copy out */
5776         if (!mddev->bitmap_info.file)
5777                 file->pathname[0] = '\0';

Signed-off-by: Benjamin Randazzo <benjamin@randazzo.fr>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16 20:52:13 -07:00
NeilBrown
4731b65de6 md/raid1: fix test for 'was read error from last working device'.
commit 34cab6f420 upstream.

When we get a read error from the last working device, we don't
try to repair it, and don't fail the device.  We simple report a
read error to the caller.

However the current test for 'is this the last working device' is
wrong.
When there is only one fully working device, it assumes that a
non-faulty device is that device.  However a spare which is rebuilding
would be non-faulty but so not the only working device.

So change the test from "!Faulty" to "In_sync".  If ->degraded says
there is only one fully working device and this device is in_sync,
this must be the one.

This bug has existed since we allowed read_balance to read from
a recovering spare in v3.0

Reported-and-tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Fixes: 76073054c9 ("md/raid1: clean up read_balance.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-10 12:21:55 -07:00
Mike Snitzer
9bf9f8b09d Revert "dm: only run the queue on completion if congested or no requests pending"
commit 621739b00e upstream.

This reverts commit 9a0e609e3f.
(Resolved a conflict during revert due to commit bfebd1cdb4 that came
after)

This revert is motivated by a couple failure reports on request-based DM
multipath testbeds:
1) Netapp reported that their multipath fault injection test under heavy
   IO load can stall longer than 300 seconds.
2) IBM reported elevated lock contention in their testbed (likely due to
   increased back pressure due to IO not being dispatched as quickly):
   https://www.redhat.com/archives/dm-devel/2015-July/msg00057.html

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-10 12:21:54 -07:00
Firo Yang
528feaeaf1 md: fix a build warning
commit 4e02361232 upstream.

Warning like this:

drivers/md/md.c: In function "update_array_info":
drivers/md/md.c:6394:26: warning: logical not is only applied
to the left hand side of comparison [-Wlogical-not-parentheses]
      !mddev->persistent  != info->not_persistent||

Fix it as Neil Brown said:
mddev->persistent != !info->not_persistent ||

Signed-off-by: Firo Yang <firogm@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:13 -07:00
Goldwyn Rodrigues
7640ca524e md: Skip cluster setup for dm-raid
commit d3b178adb3 upstream.

There is a bug that the bitmap superblock isn't initialised properly for
dm-raid, so a new field can have garbage in new fields.
(dm-raid does initialisation in the kernel - md initialised the
 superblock in mdadm).

This means that for dm-raid we cannot currently trust the new ->nodes
field. So:
 - use __GFP_ZERO to initialise the superblock properly for all new
    arrays
 - initialise all fields in bitmap_info in bitmap_new_disk_sb
 - ignore ->nodes for dm arrays (yes, this is a hack)

This bug exposes dm-raid to bug in the (still experimental) md-cluster
code, so it is suitable for -stable.  It does cause crashes.

References: https://bugzilla.kernel.org/show_bug.cgi?id=100491
Signed-off-By: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:13 -07:00
NeilBrown
0f9457afe1 md: unlock mddev_lock on an error path.
commit 9a8c0fa861 upstream.

This error path retuns while still holding the lock - bad.

Fixes: 6791875e2e ("md: make reconfig_mutex optional for writes to md sysfs files.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:13 -07:00
NeilBrown
adeb846a6d md: clear mddev->private when it has been freed.
commit bd6919228d upstream.

If ->private is set when ->run is called, it is assumed to be
a 'config'  prepared as part of 'reshape'.

So it is important when we free that config, that we also clear ->private.
This is not often a problem as the mddev will normally be discarded
shortly after the config us freed.
However if an 'assemble' races with a final close, the assemble can use
the old mddev which has a stale ->private.  This leads to any of
various sorts of crashes.

So clear ->private after calling ->free().

Reported-by: Nate Clark <nate@neworld.us>
Fixes: afa0f557cb ("md: rename ->stop to ->free")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:12 -07:00
Joe Thornber
be22af9f28 dm btree: silence lockdep lock inversion in dm_btree_del()
commit 1c7518794a upstream.

Allocate memory using GFP_NOIO when deleting a btree.  dm_btree_del()
can be called via an ioctl and we don't want to recurse into the FS or
block layer.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:07 -07:00
Joe Thornber
b2ce140833 dm thin: allocate the cell_sort_array dynamically
commit a822c83e47 upstream.

Given the pool's cell_sort_array holds 8192 pointers it triggers an
order 5 allocation via kmalloc.  This order 5 allocation is prone to
failure as system memory gets more fragmented over time.

Fix this by allocating the cell_sort_array using vmalloc.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:06 -07:00
Dennis Yang
3fa6173cb7 dm btree remove: fix bug in redistribute3
commit 4c7e309340 upstream.

redistribute3() shares entries out across 3 nodes.  Some entries were
being moved the wrong way, breaking the ordering.  This manifested as a
BUG() in dm-btree-remove.c:shift() when entries were removed from the
btree.

For additional context see:
https://www.redhat.com/archives/dm-devel/2015-May/msg00113.html

Signed-off-by: Dennis Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:06 -07:00
Joe Thornber
0cb6b5abbc dm space map metadata: fix occasional leak of a metadata block on resize
commit 6096d91af0 upstream.

The metadata space map has a simplified 'bootstrap' mode that is
operational when extending the space maps.  Whilst in this mode it's
possible for some refcount decrement operations to become queued (eg, as
a result of shadowing one of the bitmap indexes).  These decrements were
not being applied when switching out of bootstrap mode.

The effect of this bug was the leaking of a 4k metadata block.  This is
detected by the latest version of thin_check as a non fatal error.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:06 -07:00
Mikulas Patocka
3198d36127 dm stats: fix divide by zero if 'number_of_areas' arg is zero
commit dd4c1b7d0c upstream.

If the number_of_areas argument was zero the kernel would crash on
div-by-zero.  Add better input validation.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:06 -07:00
Joe Thornber
3bf9ad4c48 dm cache: fix race when issuing a POLICY_REPLACE operation
commit fb4100ae7f upstream.

There is a race between a policy deciding to replace a cache entry,
the core target writing back any dirty data from this block, and other
IO threads doing IO to the same block.

This sort of problem is avoided most of the time by the core target
grabbing a bio prison cell before making the request to the policy.
But for a demotion the core target doesn't know which block will be
demoted, so can't do this in advance.

Fix this demotion race by introducing a callback to the policy interface
that allows the policy to grab the cell on behalf of the core target.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 09:29:06 -07:00
NeilBrown
ea358cd0d2 md: make sure MD_RECOVERY_DONE is clear before starting recovery/resync
MD_RECOVERY_DONE is normally cleared by md_check_recovery after a
resync etc finished.  However it is possible for raid5_start_reshape
to race and start a reshape before MD_RECOVERY_DONE is cleared.  This
can lean to multiple reshapes running at the same time, which isn't
good.

To make sure it is cleared before starting a reshape, and also clear
it when reaping a thread, just to be safe.

Signed-off-by: NeilBrown  <neilb@suse.de>
2015-06-12 20:16:33 +10:00
NeilBrown
8e8e2518fc md: Close race when setting 'action' to 'idle'.
Checking ->sync_thread without holding the mddev_lock()
isn't really safe, even after flushing the workqueue which
ensures md_start_sync() has been run.

While this code is waiting for the lock, md_check_recovery could reap
the thread itself, and then start another thread (e.g. recovery might
finish, then reshape starts).  When this thread gets the lock
md_start_sync() hasn't run so it doesn't get reaped, but
MD_RECOVERY_RUNNING gets cleared.  This allows two threads to start
which leads to confusion.

So don't both if MD_RECOVERY_RUNNING isn't set, but if it is do
the flush and the test and the reap all under the mddev_lock to
avoid any race with md_check_recovery.

Signed-off-by: NeilBrown <neilb@suse.de>
Fixes: 6791875e2e ("md: make reconfig_mutex optional for writes to md sysfs files.")
Cc: stable@vger.kernel.org (v4.0+)
2015-06-12 20:16:26 +10:00
NeilBrown
c008f1d356 md: don't return 0 from array_state_store
Returning zero from a 'store' function is bad.
The return value should be either len length of the string
or an error.

So use 'len' if 'err' is zero.

Fixes: 6791875e2e ("md: make reconfig_mutex optional for writes to md sysfs files.")
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel (v4.0+)
2015-06-12 20:16:16 +10:00
Linus Torvalds
0f1e5b5d19 Quite a few fixes for DM's blk-mq support thanks to extra DM multipath
testing from Junichi Nomura and Bart Van Assche.
 
 Also fix a casting bug in dm_merge_bvec() that could cause only a single
 page to be added to a bio (Joe identified this while testing dm-cache
 writeback).
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Merge tag 'dm-4.1-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes from Mike Snitzer:
 "Quite a few fixes for DM's blk-mq support thanks to extra DM multipath
  testing from Junichi Nomura and Bart Van Assche.

  Also fix a casting bug in dm_merge_bvec() that could cause only a
  single page to be added to a bio (Joe identified this while testing
  dm-cache writeback)"

* tag 'dm-4.1-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix casting bug in dm_merge_bvec()
  dm: fix reload failure of 0 path multipath mapping on blk-mq devices
  dm: fix false warning in free_rq_clone() for unmapped requests
  dm: requeue from blk-mq dm_mq_queue_rq() using BLK_MQ_RQ_QUEUE_BUSY
  dm mpath: fix leak of dm_mpath_io structure in blk-mq .queue_rq error path
  dm: fix NULL pointer when clone_and_map_rq returns !DM_MAPIO_REMAPPED
  dm: run queue on re-queue
2015-05-29 14:39:24 -07:00
Joe Thornber
1c220c69ce dm: fix casting bug in dm_merge_bvec()
dm_merge_bvec() was originally added in f6fccb ("dm: introduce
merge_bvec_fn").  In that commit a value in sectors is converted to
bytes using << 9, and then assigned to an int.  This code made
assumptions about the value of BIO_MAX_SECTORS.

A later commit 148e51 ("dm: improve documentation and code clarity in
dm_merge_bvec") was meant to have no functional change but it removed
the use of BIO_MAX_SECTORS in favor of using queue_max_sectors().  At
this point the cast from sector_t to int resulted in a zero value.  The
fallout being dm_merge_bvec() would only allow a single page to be added
to a bio.

This interim fix is minimal for the benefit of stable@ because the more
comprehensive cleanup of passing a sector_t to all DM targets' merge
function will impact quite a few DM targets.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.19+
2015-05-29 13:41:16 -04:00
Junichi Nomura
15b94a6904 dm: fix reload failure of 0 path multipath mapping on blk-mq devices
dm-multipath accepts 0 path mapping.

  # echo '0 2097152 multipath 0 0 0 0' | dmsetup create newdev

Such a mapping can be used to release underlying devices while still
holding requests in its queue until working paths come back.

However, once the multipath device is created over blk-mq devices,
it rejects reloading of 0 path mapping:

  # echo '0 2097152 multipath 0 0 1 1 queue-length 0 1 1 /dev/sda 1' \
      | dmsetup create mpath1
  # echo '0 2097152 multipath 0 0 0 0' | dmsetup load mpath1
  device-mapper: reload ioctl on mpath1 failed: Invalid argument
  Command failed

With following kernel message:
  device-mapper: ioctl: can't change device type after initial table load.

DM tries to inherit the current table type using dm_table_set_type()
but it doesn't work as expected because of unnecessary check about
whether the target type is hybrid or not.

Hybrid type is for targets that work as either request-based or bio-based
and not required for blk-mq or non blk-mq checking.

Fixes: 65803c2059 ("dm table: train hybrid target type detection to select blk-mq if appropriate")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29 13:41:16 -04:00
Linus Torvalds
c492e2d464 Assorted fixes for new RAID5 stripe-batching functionality.
Unfortunately this functionality was merged a little prematurely.
 The necessary testing and code review is now complete (or as
 complete as it can be) and to code passes a variety of tests
 and looks quite sensible.
 
 Also a fix for some recent locking changes - a race was introduced
 which causes a reshape request to sometimes fail.  No data safety issues.
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Merge tag 'md/4.1-rc5-fixes' of git://neil.brown.name/md

Pull m,ore md bugfixes gfrom Neil Brown:
 "Assorted fixes for new RAID5 stripe-batching functionality.

  Unfortunately this functionality was merged a little prematurely.  The
  necessary testing and code review is now complete (or as complete as
  it can be) and to code passes a variety of tests and looks quite
  sensible.

  Also a fix for some recent locking changes - a race was introduced
  which causes a reshape request to sometimes fail.  No data safety
  issues"

* tag 'md/4.1-rc5-fixes' of git://neil.brown.name/md:
  md: fix race when unfreezing sync_action
  md/raid5: break stripe-batches when the array has failed.
  md/raid5: call break_stripe_batch_list from handle_stripe_clean_event
  md/raid5: be more selective about distributing flags across batch.
  md/raid5: add handle_flags arg to break_stripe_batch_list.
  md/raid5: duplicate some more handle_stripe_clean_event code in break_stripe_batch_list
  md/raid5: remove condition test from check_break_stripe_batch_list.
  md/raid5: Ensure a batch member is not handled prematurely.
  md/raid5: close race between STRIPE_BIT_DELAY and batching.
  md/raid5: ensure whole batch is delayed for all required bitmap updates.
2015-05-29 10:35:21 -07:00
Mike Snitzer
e5d8de32cc dm: fix false warning in free_rq_clone() for unmapped requests
When stacking request-based dm device on non blk-mq device and
device-mapper target could not map the request (error target is used,
multipath target with all paths down, etc), the WARN_ON_ONCE() in
free_rq_clone() will trigger when it shouldn't.

The warning was added by commit aa6df8d ("dm: fix free_rq_clone() NULL
pointer when requeueing unmapped request").  But free_rq_clone() with
clone->q == NULL is valid usage for the case where
dm_kill_unmapped_request() initiates request cleanup.

Fix this false warning by just removing the WARN_ON -- it only generated
false positives and was never useful in catching the intended case
(completing clone request not being mapped e.g. clone->q being NULL).

Fixes: aa6df8d ("dm: fix free_rq_clone() NULL pointer when requeueing unmapped request")
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29 11:07:36 -04:00
NeilBrown
56ccc1125b md: fix race when unfreezing sync_action
A recent change removed the need for locking around writing
to "sync_action" (and various other places), but introduced a
subtle race.
When e.g. setting 'reshape' on a 'frozen' array, the 'frozen'
flag is cleared before 'reshape' is set, so the md thread can
get in and start trying recovery - which isn't wanted.

So instead of clearing MD_RECOVERY_FROZEN for any command
except 'frozen', only clear it when each specific command
is parsed.  This allows the handling of 'reshape' to clear
the bit while a lock is held.

Also remove some places where we set MD_RECOVERY_NEEDED,
as it is always set on non-error exit of the function.


Signed-off-by: NeilBrown <neilb@suse.de>
Fixes: 6791875e2e ("md: make reconfig_mutex optional for writes to md sysfs files.")
2015-05-28 18:04:45 +10:00
NeilBrown
626f2092c8 md/raid5: break stripe-batches when the array has failed.
Once the array has too much failure, we need to break
stripe-batches up so they can all be dealt with.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:48:59 +10:00
NeilBrown
787b76fa37 md/raid5: call break_stripe_batch_list from handle_stripe_clean_event
Now that the code in break_stripe_batch_list() is nearly identical
to the end of handle_stripe_clean_event, replace the later
with a function call.

The only remaining difference of any interest is the masking that is
applieds to dev[i].flags copied from head_sh.
R5_WriteError certainly isn't wanted as it is set per-stripe, not
per-patch.  R5_Overlap isn't wanted as it is explicitly handled.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:47:02 +10:00
NeilBrown
1b956f7a8f md/raid5: be more selective about distributing flags across batch.
When a batch of stripes is broken up, we keep some of the flags
that were per-stripe, and copy other flags from the head to all
others.

This only happens while a stripe is being handled, so many of the
flags are irrelevant.

The "SYNC_FLAGS" (which I've renamed to make it clear there are
several) and STRIPE_DEGRADED are set per-stripe and so need to be
preserved.  STRIPE_INSYNC is the only flag that is set on the head
that needs to be propagated to all others.

For safety, add a WARN_ON if others are set, except:
 STRIPE_HANDLE - this is safe and per-stripe and we are going to set
      in several cases anyway
 STRIPE_INSYNC
 STRIPE_IO_STARTED - this is just a hint and doesn't hurt.
 STRIPE_ON_PLUG_LIST
 STRIPE_ON_RELEASE_LIST - It is a point pointless for a batched
           stripe to be on one of these lists, but it can happen
           as can be safely ignored.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:40:01 +10:00
NeilBrown
3960ce7961 md/raid5: add handle_flags arg to break_stripe_batch_list.
When we break a stripe_batch_list we sometimes want to set
STRIPE_HANDLE on the individual stripes, and sometimes not.

So pass a 'handle_flags' arg.  If it is zero, always set STRIPE_HANDLE
(on non-head stripes).  If not zero, only set it if any of the given
flags are present.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:39:30 +10:00
NeilBrown
fb642b92c2 md/raid5: duplicate some more handle_stripe_clean_event code in break_stripe_batch_list
break_stripe_batch list didn't clear head_sh->batch_head.
This was probably a bug.

Also clear all R5_Overlap flags and if any were cleared, wake up
'wait_for_overlap'.
This isn't always necessary but the worst effect is a little
extra checking for code that is waiting on wait_for_overlap.

Also, don't use wake_up_nr() because that does the wrong thing
if 'nr' is zero, and it number of flags cleared doesn't
strongly correlate with the number of threads to wake.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:36:25 +10:00
NeilBrown
4e3d62ff49 md/raid5: remove condition test from check_break_stripe_batch_list.
handle_stripe_clean_event() contains a chunk of code very
similar to check_break_stripe_batch_list().
If we make the latter more like the former, we can end up
with just one copy of this code.

This  first step removed the condition (and the 'check_') part
of the name.  This has the added advantage of making it clear
what check is being performed at the point where the function is
called.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:36:06 +10:00
NeilBrown
b15a9dbdbf md/raid5: Ensure a batch member is not handled prematurely.
If a stripe is a member of a batch, but not the head, it must
not be handled separately from the rest of the batch.

'clear_batch_ready()' handles this requirement to some
extent but not completely.  If a member is passed to handle_stripe()
a second time it returns '0' indicating the stripe can be handled,
which is wrong.
So add an extra test.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:35:47 +10:00
NeilBrown
d0852df543 md/raid5: close race between STRIPE_BIT_DELAY and batching.
When we add a write to a stripe we need to make sure the bitmap
bit is set.  While doing that the stripe is not locked so it could
be added to a batch after which further changes to STRIPE_BIT_DELAY
and ->bm_seq are ineffective.

So we need to hold off adding to a stripe until bitmap_startwrite has
completed at least once, and we need to avoid further changes to
STRIPE_BIT_DELAY once the stripe has been added to a batch.

If a bitmap_startwrite() completes after the stripe was added to a
batch, it will not have set the bit, only incremented a counter, so no
extra delay of the stripe is needed.

Reported-by: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:34:40 +10:00
NeilBrown
2b6b245742 md/raid5: ensure whole batch is delayed for all required bitmap updates.
When we add a stripe to a batch, we need to be sure that
head stripe will wait for the bitmap update required for the new
stripe.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-28 11:29:14 +10:00
Mike Snitzer
45714fbed4 dm: requeue from blk-mq dm_mq_queue_rq() using BLK_MQ_RQ_QUEUE_BUSY
Use BLK_MQ_RQ_QUEUE_BUSY to requeue a blk-mq request directly from the
DM blk-mq device's .queue_rq.  This cleans up the previous convoluted
handling of request requeueing that would return BLK_MQ_RQ_QUEUE_OK
(even though it wasn't) and then run blk_mq_requeue_request() followed
by blk_mq_kick_requeue_list().

Also, document that DM blk-mq ontop of old request_fn devices cannot
fail in clone_rq() since the clone request is preallocated as part of
the pdu.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-27 17:37:23 -04:00
Mike Snitzer
4c6dd53dd3 dm mpath: fix leak of dm_mpath_io structure in blk-mq .queue_rq error path
Otherwise kmemleak reported:

unreferenced object 0xffff88009b14e2b0 (size 16):
  comm "fio", pid 4274, jiffies 4294978034 (age 1253.210s)
  hex dump (first 16 bytes):
    40 12 f3 99 01 88 ff ff 00 10 00 00 00 00 00 00  @...............
  backtrace:
    [<ffffffff81600029>] kmemleak_alloc+0x49/0xb0
    [<ffffffff811679a8>] kmem_cache_alloc+0xf8/0x160
    [<ffffffff8111c950>] mempool_alloc_slab+0x10/0x20
    [<ffffffff8111cb37>] mempool_alloc+0x57/0x150
    [<ffffffffa04d2b61>] __multipath_map.isra.17+0xe1/0x220 [dm_multipath]
    [<ffffffffa04d2cb5>] multipath_clone_and_map+0x15/0x20 [dm_multipath]
    [<ffffffffa02889b5>] map_request.isra.39+0xd5/0x220 [dm_mod]
    [<ffffffffa028b0e4>] dm_mq_queue_rq+0x134/0x240 [dm_mod]
    [<ffffffff812cccb5>] __blk_mq_run_hw_queue+0x1d5/0x380
    [<ffffffff812ccaa5>] blk_mq_run_hw_queue+0xc5/0x100
    [<ffffffff812ce350>] blk_sq_make_request+0x240/0x300
    [<ffffffff812c0f30>] generic_make_request+0xc0/0x110
    [<ffffffff812c0ff2>] submit_bio+0x72/0x150
    [<ffffffff811c07cb>] do_blockdev_direct_IO+0x1f3b/0x2da0
    [<ffffffff811c166e>] __blockdev_direct_IO+0x3e/0x40
    [<ffffffff8120aa1a>] ext4_direct_IO+0x1aa/0x390

Fixes: e5863d9ad ("dm: allocate requests in target when stacking on blk-mq devices")
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.0+
2015-05-27 17:37:22 -04:00
Junichi Nomura
3a1407559a dm: fix NULL pointer when clone_and_map_rq returns !DM_MAPIO_REMAPPED
When stacking request-based DM on blk_mq device, request cloning and
remapping are done in a single call to target's clone_and_map_rq().
The clone is allocated and valid only if clone_and_map_rq() returns
DM_MAPIO_REMAPPED.

The "IS_ERR(clone)" check in map_request() does not cover all the
!DM_MAPIO_REMAPPED cases that are possible (E.g. if underlying devices
are not ready or unavailable, clone_and_map_rq() may return
DM_MAPIO_REQUEUE without ever having established an ERR_PTR).  Fix this
by explicitly checking for a return that is not DM_MAPIO_REMAPPED in
map_request().

Without this fix, DM core may call setup_clone() for a NULL clone
and oops like this:

   BUG: unable to handle kernel NULL pointer dereference at 0000000000000068
   IP: [<ffffffff81227525>] blk_rq_prep_clone+0x7d/0x137
   ...
   CPU: 2 PID: 5793 Comm: kdmwork-253:3 Not tainted 4.0.0-nm #1
   ...
   Call Trace:
    [<ffffffffa01d1c09>] map_tio_request+0xa9/0x258 [dm_mod]
    [<ffffffff81071de9>] kthread_worker_fn+0xfd/0x150
    [<ffffffff81071cec>] ? kthread_parkme+0x24/0x24
    [<ffffffff81071cec>] ? kthread_parkme+0x24/0x24
    [<ffffffff81071fdd>] kthread+0xe6/0xee
    [<ffffffff81093a59>] ? put_lock_stats+0xe/0x20
    [<ffffffff81071ef7>] ? __init_kthread_worker+0x5b/0x5b
    [<ffffffff814c2d98>] ret_from_fork+0x58/0x90
    [<ffffffff81071ef7>] ? __init_kthread_worker+0x5b/0x5b

Fixes: e5863d9ad ("dm: allocate requests in target when stacking on blk-mq devices")
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.0+
2015-05-27 09:48:51 -04:00
Junichi Nomura
4ae9944d13 dm: run queue on re-queue
Without kicking queue, requeued request may stay forever in
the queue if there are no other I/O activities to the device.

The original error had been in v2.6.39 with commit 7eaceaccab
("block: remove per-queue plugging"), which replaced conditional
plugging by periodic runqueue.

Commit 9d1deb83d4 in v4.1-rc1 removed the periodic runqueue
and the problem started to manifest.

Fixes: 9d1deb83d4 ("dm: don't schedule delayed run of the queue if nothing to do")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-26 09:57:36 -04:00
Linus Torvalds
a30ec4b347 md fixes for 4.1-rc4
- one serious RAID0 data corruption - caused by recent bugfix that wasn't
   reviewed properly.
 - one raid5 fix in new code (a couple more of those to come).
 - one little fix to stop static analysis complaining about silly rcu
   annotation.
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Merge tag 'md/4.1-rc4-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "I have a few more raid5 bugfixes pending, but I want them to get a bit
  more review first.  In the meantime:

   - one serious RAID0 data corruption - caused by recent bugfix that
     wasn't reviewed properly.

   - one raid5 fix in new code (a couple more of those to come).

   - one little fix to stop static analysis complaining about silly rcu
     annotation"

* tag 'md/4.1-rc4-fixes' of git://neil.brown.name/md:
  md/bitmap: remove rcu annotation from pointer arithmetic.
  md/raid0: fix restore to sector variable in raid0_make_request
  raid5: fix broken async operation chain
2015-05-22 15:10:07 -07:00
NeilBrown
8532e34390 md/bitmap: remove rcu annotation from pointer arithmetic.
Evaluating  "&mddev->disks" is simple pointer arithmetic, so
it does not need 'rcu' annotations - no dereferencing is happening.

Also enhance the comment to explain that 'rdev' in that case
is not actually a pointer to an rdev.

Reported-by: Patrick Marlier <patrick.marlier@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-21 09:14:41 +10:00
Eric Work
a81157768a md/raid0: fix restore to sector variable in raid0_make_request
The variable "sector" in "raid0_make_request()" was improperly updated
by a call to "sector_div()" which modifies its first argument in place.
Commit 47d68979cc restored this variable
after the call for later re-use.  Unfortunetly the restore was done after
the referenced variable "bio" was advanced.  This lead to the original
value and the restored value being different.  Here we move this line to
the proper place.

One observed side effect of this bug was discarding a file though
unlinking would cause an unrelated file's contents to be discarded.

Signed-off-by: NeilBrown <neilb@suse.de>
Fixes: 47d68979cc ("md/raid0: fix bug with chunksize not a power of 2.")
Cc: stable@vger.kernel.org (any that received above backport)
URL: https://bugzilla.kernel.org/show_bug.cgi?id=98501
2015-05-21 09:14:25 +10:00
Shaohua Li
487696957e raid5: fix broken async operation chain
ops_run_reconstruct6() doesn't correctly chain asyn operations. The tx returned
by async_gen_syndrome should be added as the dependent tx of next stripe.

The issue is introduced by commit 59fc630b8b
    RAID5: batch adjacent full stripe write

Reported-and-tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-21 09:14:20 +10:00
Linus Torvalds
c91aa67eed A few fixes for md.
Most of these are related to the new "batched stripe writeout",
 but there are a few others.
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Merge tag 'md/4.1-rc3-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "A few fixes for md.

  Most of these are related to the new "batched stripe writeout", but
  there are a few others"

* tag 'md/4.1-rc3-fixes' of git://neil.brown.name/md:
  md/raid5: fix handling of degraded stripes in batches.
  md/raid5: fix allocation of 'scribble' array.
  md/raid5: don't record new size if resize_stripes fails.
  md/raid5: avoid reading parity blocks for full-stripe write to degraded array
  md/raid5: more incorrect BUG_ON in handle_stripe_fill.
  md/raid5: new alloc_stripe() to allocate an initialize a stripe.
  md-raid0: conditional mddev->queue access to suit dm-raid
2015-05-11 10:33:31 -07:00
Linus Torvalds
5d5df5ee7c Two additional fixes for changes introduced via DM during the 4.1 merge
window: The first reverts a dm-crypt change that wasn't correct.  The
 second fixes a device format regression that impacted userspace.
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Merge tag 'dm-4.1-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "Two additional fixes for changes introduced via DM during the 4.1
  merge window.

  The first reverts a dm-crypt change that wasn't correct.  The second
  fixes a device format regression that impacted userspace"

* tag 'dm-4.1-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  init: fix regression by supporting devices with major:minor:offset format
  Revert "dm crypt: fix deadlock when async crypto algorithm returns -EBUSY"
2015-05-08 20:38:21 -07:00
Linus Torvalds
1daac193f2 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "A collection of fixes since the merge window;

   - fix for a double elevator module release, from Chao Yu.  Ancient bug.

   - the splice() MORE flag fix from Christophe Leroy.

   - a fix for NVMe, fixing a patch that went in in the merge window.
     From Keith.

   - two fixes for blk-mq CPU hotplug handling, from Ming Lei.

   - bdi vs blockdev lifetime fix from Neil Brown, fixing and oops in md.

   - two blk-mq fixes from Shaohua, fixing a race on queue stop and a
     bad merge issue with FUA writes.

   - division-by-zero fix for writeback from Tejun.

   - a block bounce page accounting fix, making sure we inc/dec after
     bouncing so that pre/post IO pages match up.  From Wang YanQing"

* 'for-linus' of git://git.kernel.dk/linux-block:
  splice: sendfile() at once fails for big files
  blk-mq: don't lose requests if a stopped queue restarts
  blk-mq: fix FUA request hang
  block: destroy bdi before blockdev is unregistered.
  block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE
  elevator: fix double release of elevator module
  writeback: use |1 instead of +1 to protect against div by zero
  blk-mq: fix CPU hotplug handling
  blk-mq: fix race between timeout and CPU hotplug
  NVMe: Fix VPD B0 max sectors translation
2015-05-08 19:49:35 -07:00
NeilBrown
bb27051f9f md/raid5: fix handling of degraded stripes in batches.
There is no need for special handling of stripe-batches when the array
is degraded.

There may be if there is a failure in the batch, but STRIPE_DEGRADED
does not imply an error.

So don't set STRIPE_BATCH_ERR in ops_run_io just because the array is
degraded.
This actually causes a bug: the STRIPE_DEGRADED flag gets cleared in
check_break_stripe_batch_list() and so the bitmap bit gets cleared
when it shouldn't.

So in check_break_stripe_batch_list(), split the batch up completely -
again STRIPE_DEGRADED isn't meaningful.

Also don't set STRIPE_BATCH_ERR when there is a write error to a
replacement device.  This simply removes the replacement device and
requires no extra handling.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-05-08 18:47:57 +10:00