Commit Graph

4629 Commits

Author SHA1 Message Date
Mike Snitzer e99dda8fc4 dm cache policy smq: use hash_32() instead of hash_32_generic()
Switch to using hash_32() because hash_32_generic() should only be used
by the kernel's selftests.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 19:42:37 -05:00
Ondrej Kozina 027c431ccf dm crypt: reject key strings containing whitespace chars
Unfortunately key_string may theoretically contain whitespace even after
it's processed by dm_split_args().  The reason for this is DM core
supports escaping of almost all chars including any whitespace.

If userspace passes a key to the kernel in format ":32:logon:my_prefix:my\ key"
dm-crypt will look up key "my_prefix:my key" in kernel keyring service.
So far everything's fine.

Unfortunately if userspace later calls DM_TABLE_STATUS ioctl, it will not
receive back expected ":32:logon:my_prefix:my\ key" but the unescaped version
instead.  Also userpace (most notably cryptsetup) is not ready to parse
single target argument containing (even escaped) whitespace chars and any
whitespace is simply taken as delimiter of another argument.

This effect is mitigated by the fact libdevmapper curently performs
double escaping of '\' char.  Any user input in format "x\ x" is
transformed into "x\\ x" before being passed to the kernel.  Nonetheless
dm-crypt may be used without libdevmapper.  Therefore the near-term
solution to this is to reject any key string containing whitespace.

Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:16 -05:00
Benjamin Marzinski b446396b74 dm space map: always set ev if sm_ll_mutate() succeeds
If no block was allocated or freed, sm_ll_mutate() wasn't setting
*ev, leaving the variable unitialized. sm_ll_insert(),
sm_disk_inc_block(), and sm_disk_new_block() all check ev to see
if there was an allocation event in sm_ll_mutate(), possibly
reading unitialized data.

If no allocation event occured, sm_ll_mutate() should set *ev
to SM_NONE.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:15 -05:00
Benjamin Marzinski 0c79ce0b75 dm space map metadata: skip useless memcpy in metadata_ll_init_index()
When metadata_ll_init_index() is called by sm_ll_new_metadata(),
ll->mi_le hasn't been initialized yet. So, when
metadata_ll_init_index() copies the contents of ll->mi_le into the
newly allocated bitmap_root, it is just copying garbage. ll->mi_le
will be allocated later in sm_ll_extend() and copied into the
bitmap_root, in sm_ll_commit().

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:15 -05:00
Benjamin Marzinski 314c25c56c dm space map metadata: fix 'struct sm_metadata' leak on failed create
In dm_sm_metadata_create() we temporarily change the dm_space_map
operations from 'ops' (whose .destroy function deallocates the
sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't).

If dm_sm_metadata_create() fails in sm_ll_new_metadata() or
sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls
dm_sm_destroy() with the intention of freeing the sm_metadata, but it
doesn't (because the dm_space_map operations is still set to
'bootstrap_ops').

Fix this by setting the dm_space_map operations back to 'ops' if
dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2016-12-08 14:13:14 -05:00
Heinz Mauelshagen 11e2968478 dm raid: fix discard support regression
Commit ecbfb9f118 ("dm raid: add raid level takeover support") moved the
configure_discard_support() call from raid_ctr() to raid_preresume().

Enabling/disabling discard _must_ happen during table load (through the
.ctr hook).  Fix this regression by moving the
configure_discard_support() call back to raid_ctr().

Fixes: ecbfb9f118 ("dm raid: add raid level takeover support")
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:12 -05:00
Heinz Mauelshagen affa9d28f7 dm raid: don't allow "write behind" with raid4/5/6
Remove CTR_FLAG_MAX_WRITE_BEHIND from raid4/5/6's valid ctr flags.

Only the md raid1 personality supports setting a maximum number
of "write behind" write IOs on any legs set to "write mostly".
"write mostly" enhances throughput with slow links/disks.

Technically the "write behind" value is a write intent bitmap
property only being respected by the raid1 personality.  It allows a
maximum number of "write behind" writes to any "write mostly" raid1
mirror legs to be delayed and avoids reads from such legs.

No other MD personalities supported via dm-raid make use of "write
behind", thus setting this property is superfluous; it wouldn't cause
harm but it is correct to reject it.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:11 -05:00
tang.junhui 54cd640d20 dm mpath: use hw_handler_params if attached hw_handler is same as requested
Let the requested m->hw_handler_params be used if the attached hardware
handler is the same handler as requested with m->hw_handler_name.

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:10 -05:00
Ondrej Kozina c538f6ec9f dm crypt: add ability to use keys from the kernel key retention service
The kernel key service is a generic way to store keys for the use of
other subsystems. Currently there is no way to use kernel keys in dm-crypt.
This patch aims to fix that. Instead of key userspace may pass a key
description with preceding ':'. So message that constructs encryption
mapping now looks like this:

  <cipher> [<key>|:<key_string>] <iv_offset> <dev_path> <start> [<#opt_params> <opt_params>]

where <key_string> is in format: <key_size>:<key_type>:<key_description>

Currently we only support two elementary key types: 'user' and 'logon'.
Keys may be loaded in dm-crypt either via <key_string> or using
classical method and pass the key in hex representation directly.

dm-crypt device initialised with a key passed in hex representation may be
replaced with key passed in key_string format and vice versa.

(Based on original work by Andrey Ryabinin)

Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:09 -05:00
Bart Van Assche 0637018dff dm array: remove a dead assignment in populate_ablock_with_values()
A value is assigned to 'nr_entries' but is never used, remove it.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:09 -05:00
Bart Van Assche 6080758d44 dm ioctl: use offsetof() instead of open-coding it
Subtracting sizes is a fragile approach because the result is only
correct if the compiler has not added any padding at the end of the
structure. Hence use offsetof() instead of size subtraction. An
additional advantage of offsetof() is that it makes the intent more
clear.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:08 -05:00
Bart Van Assche b23df0d048 dm rq: simplify use_blk_mq initialization
Use a single statement to declare and initialize 'use_blk_mq' instead
of two statements.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:07 -05:00
Bart Van Assche 2e91c36941 dm: use blk_set_queue_dying() in __dm_destroy()
After QUEUE_FLAG_DYING has been set any code that is waiting in
get_request() should be woken up.  But to get this behaviour
blk_set_queue_dying() must be used instead of only setting
QUEUE_FLAG_DYING.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:06 -05:00
Mikulas Patocka 41c73a49df dm bufio: drop the lock when doing GFP_NOIO allocation
If the first allocation attempt using GFP_NOWAIT fails, drop the lock
and retry using GFP_NOIO allocation (lock is dropped because the
allocation can take some time).

Note that we won't do GFP_NOIO allocation when we loop for the second
time, because the lock shouldn't be dropped between __wait_for_free_buffer
and __get_unclaimed_buffer.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:05 -05:00
Mikulas Patocka d12067f428 dm bufio: don't take the lock in dm_bufio_shrink_count
dm_bufio_shrink_count() is called from do_shrink_slab to find out how many
freeable objects are there. The reported value doesn't have to be precise,
so we don't need to take the dm-bufio lock.

Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:04 -05:00
Douglas Anderson 9ea61cac0b dm bufio: avoid sleeping while holding the dm_bufio lock
We've seen in-field reports showing _lots_ (18 in one case, 41 in
another) of tasks all sitting there blocked on:

  mutex_lock+0x4c/0x68
  dm_bufio_shrink_count+0x38/0x78
  shrink_slab.part.54.constprop.65+0x100/0x464
  shrink_zone+0xa8/0x198

In the two cases analyzed, we see one task that looks like this:

  Workqueue: kverityd verity_prefetch_io

  __switch_to+0x9c/0xa8
  __schedule+0x440/0x6d8
  schedule+0x94/0xb4
  schedule_timeout+0x204/0x27c
  schedule_timeout_uninterruptible+0x44/0x50
  wait_iff_congested+0x9c/0x1f0
  shrink_inactive_list+0x3a0/0x4cc
  shrink_lruvec+0x418/0x5cc
  shrink_zone+0x88/0x198
  try_to_free_pages+0x51c/0x588
  __alloc_pages_nodemask+0x648/0xa88
  __get_free_pages+0x34/0x7c
  alloc_buffer+0xa4/0x144
  __bufio_new+0x84/0x278
  dm_bufio_prefetch+0x9c/0x154
  verity_prefetch_io+0xe8/0x10c
  process_one_work+0x240/0x424
  worker_thread+0x2fc/0x424
  kthread+0x10c/0x114

...and that looks to be the one holding the mutex.

The problem has been reproduced on fairly easily:
0. Be running Chrome OS w/ verity enabled on the root filesystem
1. Pick test patch: http://crosreview.com/412360
2. Install launchBalloons.sh and balloon.arm from
     http://crbug.com/468342
   ...that's just a memory stress test app.
3. On a 4GB rk3399 machine, run
     nice ./launchBalloons.sh 4 900 100000
   ...that tries to eat 4 * 900 MB of memory and keep accessing.
4. Login to the Chrome web browser and restore many tabs

With that, I've seen printouts like:
  DOUG: long bufio 90758 ms
...and stack trace always show's we're in dm_bufio_prefetch().

The problem is that we try to allocate memory with GFP_NOIO while
we're holding the dm_bufio lock.  Instead we should be using
GFP_NOWAIT.  Using GFP_NOIO can cause us to sleep while holding the
lock and that causes the above problems.

The current behavior explained by David Rientjes:

  It will still try reclaim initially because __GFP_WAIT (or
  __GFP_KSWAPD_RECLAIM) is set by GFP_NOIO.  This is the cause of
  contention on dm_bufio_lock() that the thread holds.  You want to
  pass GFP_NOWAIT instead of GFP_NOIO to alloc_buffer() when holding a
  mutex that can be contended by a concurrent slab shrinker (if
  count_objects didn't use a trylock, this pattern would trivially
  deadlock).

This change significantly increases responsiveness of the system while
in this state.  It makes a real difference because it unblocks kswapd.
In the bug report analyzed, kswapd was hung:

   kswapd0         D ffffffc000204fd8     0    72      2 0x00000000
   Call trace:
   [<ffffffc000204fd8>] __switch_to+0x9c/0xa8
   [<ffffffc00090b794>] __schedule+0x440/0x6d8
   [<ffffffc00090bac0>] schedule+0x94/0xb4
   [<ffffffc00090be44>] schedule_preempt_disabled+0x28/0x44
   [<ffffffc00090d900>] __mutex_lock_slowpath+0x120/0x1ac
   [<ffffffc00090d9d8>] mutex_lock+0x4c/0x68
   [<ffffffc000708e7c>] dm_bufio_shrink_count+0x38/0x78
   [<ffffffc00030b268>] shrink_slab.part.54.constprop.65+0x100/0x464
   [<ffffffc00030dbd8>] shrink_zone+0xa8/0x198
   [<ffffffc00030e578>] balance_pgdat+0x328/0x508
   [<ffffffc00030eb7c>] kswapd+0x424/0x51c
   [<ffffffc00023f06c>] kthread+0x10c/0x114
   [<ffffffc000203dd0>] ret_from_fork+0x10/0x40

By unblocking kswapd memory pressure should be reduced.

Suggested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:04 -05:00
Bart Van Assche 5b8c01f74c dm table: simplify dm_table_determine_type()
Use a single loop instead of two loops to determine whether or not
all_blk_mq has to be set.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:03 -05:00
Bart Van Assche 301fc3f5ef dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device
When dm_table_set_type() is used by a target to establish a DM table's
type (e.g. DM_TYPE_MQ_REQUEST_BASED in the case of DM multipath) the
DM core must go on to verify that the devices in the table are
compatible with the established type.

Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:12:53 -05:00
Mike Snitzer 6936c12cf8 dm table: fix 'all_blk_mq' inconsistency when an empty table is loaded
An earlier DM multipath table could have been build ontop of underlying
devices that were all using blk-mq.  In that case, if that active
multipath table is replaced with an empty DM multipath table (that
reflects all paths have failed) then it is important that the
'all_blk_mq' state of the active table is transfered to the new empty DM
table.  Otherwise dm-rq.c:dm_old_prep_tio() will incorrectly clone a
request that isn't needed by the DM multipath target when it is to issue
IO to an underlying blk-mq device.

Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:12:52 -05:00
Song Liu 3c6edc6608 md/r5cache: after recovery, increase journal seq by 10000
Currently, we increase journal entry seq by 10 after recovery.
However, this is not sufficient in the following case.

After crash the journal looks like

| seq+0 | +1 | +2 | +3 | +4 | +5 | +6 | +7 | ... | +11 | +12 |

If +1 is not valid, we dropped all entries from +1 to +12; and
write seq+10:

| seq+0 | +10 | +2 | +3 | +4 | +5 | +6 | +7 | ... | +11 | +12 |

However, if we write a big journal entry with seq+11, it will
connect with some stale journal entry:

| seq+0 | +10 |                     +11                 | +12 |

To reduce the risk of this issue, we increase seq by 10000 instead.

Shaohua: use 10000 instead of 1000. The risk should be very unlikely. The total
stripe cache size is less than 2k typically, and several stripes can fit into
one meta data block. So the total inflight meta data blocks would be quite
small, which means the the total sequence number used should be quite small.
The 10000 sequence number increase should be far more than safe.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-08 10:54:47 -08:00
Song Liu 5c88f403a5 md/raid5-cache: fix crc in rewrite_data_only_stripes()
r5l_recovery_create_empty_meta_block() creates crc for the empty
metablock. After the metablock is updated, we need clear the
checksum before recalculate it.

Shaohua: moved checksum calculation out of
r5l_recovery_create_empty_meta_block. We should calculate it after all fields
are updated.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-08 10:34:03 -08:00
JackieLiu d30dfeb9be md/raid5-cache: no recovery is required when create super-block
When create the super-block information, We do not need to do this
recovery stage, only need to initialize some variables.

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-08 10:01:17 -08:00
NeilBrown e2342ca832 md: fix refcount problem on mddev when stopping array.
md_open() gets a counted reference on an mddev using mddev_find().
If it ends up returning an error, it must drop this reference.

There are two error paths where the reference is not dropped.
One only happens if the process is signalled and an awkward time,
which is quite unlikely.
The other was introduced recently in commit af8d8e6f0.

Change the code to ensure the drop the reference when returning an error,
and make it harded to re-introduce this sort of bug in the future.

Reported-by: Marc Smith <marc.smith@mcc.edu>
Fixes: af8d8e6f03 ("md: changes for MD_STILL_CLOSED flag")
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-05 17:11:03 -08:00
Zhengyuan Liu 3d7e7e1d9d md/r5cache: do r5c_update_log_state after log recovery
We should update log state after we did a log recovery, current completion
may get wrong log state since log->log_start wasn't initalized until we
called r5l_recovery_log.

At log recovery stage, no lock needed as there is no race conditon.
next_checkpoint field will be initialized in r5l_recovery_log too.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-05 17:11:02 -08:00
JackieLiu 43b9674832 md/raid5-cache: adjust the write position of the empty block if no data blocks
When recovery is complete, we write an empty block and record his
position first, then make the data-only stripes rewritten done,
the location of the empty block as the last checkpoint position
to write into the super block. And we should update last_checkpoint
to this empty block position.

------------------------------------------------------------------
|  old log       | empty block | data only stripes | invalid log |
------------------------------------------------------------------
^                ^                                 ^
|                |- log->last_checkpoint           |- log->log_start
|                |- log->last_cp_seq               |- log->next_checkpoint
|- log->seq=n    |- log->seq=10+n

At the same time, if there is no data-only stripes, this scene may appear,
| meta1 | meta2 | meta3 |
meta 1 is valid, meta 2 is invalid. meta 3 could be valid. so we should
The solution is we create a new meta in meta2 with its seq == meta1's
seq + 10 and let superblock points to meta2.

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-05 17:11:02 -08:00
Song Liu f687a33ef0 md/r5cache: run_no_space_stripes() when R5C_LOG_CRITICAL == 0
With writeback cache, we define log space critical as

   free_space < 2 * reclaim_required_space

So the deassert of R5C_LOG_CRITICAL could happen when
  1. free_space increases
  2. reclaim_required_space decreases

Currently, run_no_space_stripes() is called when 1 happens, but
not (always) when 2 happens.

With this patch, run_no_space_stripes() is call when
R5C_LOG_CRITICAL is cleared.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-12-02 12:03:52 -08:00
Konstantin Khlebnikov e8d7c33232 md/raid5: limit request size according to implementation limits
Current implementation employ 16bit counter of active stripes in lower
bits of bio->bi_phys_segments. If request is big enough to overflow
this counter bio will be completed and freed too early.

Fortunately this not happens in default configuration because several
other limits prevent that: stripe_cache_size * nr_disks effectively
limits count of active stripes. And small max_sectors_kb at lower
disks prevent that during normal read/write operations.

Overflow easily happens in discard if it's enabled by module parameter
"devices_handle_discard_safely" and stripe_cache_size is set big enough.

This patch limits requests size with 256Mb - 8Kb to prevent overflows.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Shaohua Li <shli@kernel.org>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 15:53:21 -08:00
JackieLiu 1a0ec5c30c md/raid5-cache: do not need to set STRIPE_PREREAD_ACTIVE repeatedly
R5c_make_stripe_write_out has set this flag, do not need to set again.

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 14:46:23 -08:00
JackieLiu dbd22c8d7f md/raid5-cache: remove the unnecessary next_cp_seq field from the r5l_log
The next_cp_seq field is useless, remove it.

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 14:46:22 -08:00
JackieLiu bc8f167f9c md/raid5-cache: release the stripe_head at the appropriate location
If we released the 'stripe_head' in r5c_recovery_flush_log,
ctx->cached_list will both release the data-parity stripes and
data-only stripes, which will become empty.
And we also need to use the data-only stripes in
r5c_recovery_rewrite_data_only_stripes, so we should wait util rewrite
data-only stripes is done before releasing them.

Reviewed-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 14:46:22 -08:00
JackieLiu fc833c2a2f md/raid5-cache: use ring add to prevent overflow
'write_pos' must be protected with 'r5l_ring_add', or it may overflow

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 14:46:21 -08:00
JackieLiu 9b69173e5c md/raid5-cache: remove unnecessary function parameters
The function parameter 'recovery_list' is not used in
body, we can delete it

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 14:46:21 -08:00
Zhengyuan Liu 462eb7d872 raid5-cache: don't set STRIPE_R5C_PARTIAL_STRIPE flag while load stripe into cache
r5c_recovery_load_one_stripe should not set STRIPE_R5C_PARTIAL_STRIPE flag,as
the data-only stripe may be STRIPE_R5C_FULL_STRIPE stripe. The state machine
would release the stripe later and add it into neither r5c_cached_full_stripes
list or r5c_cached_partial_stripes list and set correct flag.

Reviewed-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 14:45:14 -08:00
Zhengyuan Liu f7b7bee75e raid5-cache: add another check conditon before replaying one stripe
New stripe that was just allocated has no STRIPE_R5C_CACHING state too,
add this check condition could avoid unnecessary replaying for empty stripe.

r5l_recovery_replay_one_stripe would reset stripe for any case, delete it
to make code more clean.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-29 11:56:20 -08:00
Dan Carpenter d3014e21e1 md/r5cache: enable IRQs on error path
We need to re-enable the IRQs here before returning.

Fixes: a39f7afde3 ("md/r5cache: write-out phase and reclaim support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-27 21:38:08 -08:00
Song Liu d7bd398e97 md/r5cache: handle alloc_page failure
RMW of r5c write back cache uses an extra page to store old data for
prexor. handle_stripe_dirtying() allocates this page by calling
alloc_page(). However, alloc_page() may fail.

To handle alloc_page() failures, this patch adds an extra page to
disk_info. When alloc_page fails, handle_stripe() trys to use these
pages. When these pages are used by other stripe (R5C_EXTRA_PAGE_IN_USE),
the stripe is added to delayed_list.

Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-27 21:35:38 -08:00
Shaohua Li 034e33f5ed md: stop write should stop journal reclaim
__md_stop_writes currently doesn't stop raid5-cache reclaim thread. It's
possible the reclaim thread is still running and doing write, which
doesn't match what __md_stop_writes should do. The extra ->quiesce()
call should not harm any raid types. For raid5-cache, this will
guarantee we reclaim all caches before we update superblock.

Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Cc: Song Liu <songliubraving@fb.com>
2016-11-23 19:30:25 -08:00
Shaohua Li ce1ccd079f raid5-cache: suspend reclaim thread instead of shutdown
There is mechanism to suspend a kernel thread. Use it instead of playing
create/destroy game.

Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Cc: Song Liu <songliubraving@fb.com>
2016-11-23 19:30:06 -08:00
NeilBrown 1919cbb23b md/raid10: add failfast handling for writes.
When writing to a fastfail device, we use MD_FASTFAIL unless
it is the only device being written to.  For
resync/recovery, assume there was a working device to read
from so always use MD_FASTFAIL.

If a write for resync/recovery fails, we just fail the
device - there is not much else to do.

If a normal write fails, but the device cannot be marked
Faulty (must be only one left), we queue for write error
handling which calls narrow_write_error() to write the block
synchronously without any failfast flags.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-22 09:14:42 -08:00
NeilBrown 8d3ca83dcf md/raid10: add failfast handling for reads.
If a device is marked FailFast, and it is not the only
device we can read from, we mark the bio as MD_FAILFAST.

If this does fail-fast, we don't try read repair but just
allow failure.

If it was the last device, it doesn't get marked Faulty so
the retry happens on the same device - this time without
FAILFAST.  A subsequent failure will not retry but will just
pass up the error.

During resync we may use FAILFAST requests, and on a failure
we will simply use the other device(s).

During recovery we will only use FAILFAST in the unusual
case were there are multiple places to read from - i.e. if
there are > 2 devices.  If we get a failure we will fail the
device and complete the resync/recovery with remaining
devices.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-22 09:14:28 -08:00
NeilBrown 212e7eb7a3 md/raid1: add failfast handling for writes.
When writing to a fastfail device we use MD_FASTFAIL unless
it is the only device being written to.

For resync/recovery, assume there was a working device to
read from so always use REQ_FASTFAIL_DEV.

If a write for resync/recovery fails, we just fail the
device - there is not much else to do.

If a normal failfast write fails, but the device cannot be
failed (must be only one left), we queue for write error
handling.  This will call narrow_write_error() to retry the
write synchronously and without any FAILFAST flags.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-22 09:14:10 -08:00
NeilBrown 2e52d449bc md/raid1: add failfast handling for reads.
If a device is marked FailFast and it is not the only device
we can read from, we mark the bio with REQ_FAILFAST_* flags.

If this does fail, we don't try read repair but just allow
failure.  If it was the last device it doesn't fail of
course, so the retry happens on the same device - this time
without FAILFAST.  A subsequent failure will not retry but
will just pass up the error.

During resync we may use FAILFAST requests and on a failure
we will simply use the other device(s).

During recovery we will only use FAILFAST in the unusual
case were there are multiple places to read from - i.e. if
there are > 2 devices.  If we get a failure we will fail the
device and complete the resync/recovery with remaining
devices.

The new R1BIO_FailFast flag is set on read reqest to suggest
the a FAILFAST request might be acceptable.  The rdev needs
to have FailFast set as well for the read to actually use
REQ_FAILFAST_*.

We need to know there are at least two working devices
before we can set R1BIO_FailFast, so we mustn't stop looking
at the first device we find.  So the "min_pending == 0"
handling to not exit early, but too always choose the
best_pending_disk if min_pending == 0.

The spinlocked region in raid1_error() in enlarged to ensure
that if two bios, reading from two different devices, fail
at the same time, then there is no risk that both devices
will be marked faulty, leaving zero "In_sync" devices.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-22 09:13:18 -08:00
NeilBrown 46533ff7fe md: Use REQ_FAILFAST_* on metadata writes where appropriate
This can only be supported on personalities which ensure
that md_error() never causes an array to enter the 'failed'
state.  i.e. if marking a device Faulty would cause some
data to be inaccessible, the device is status is left as
non-Faulty.  This is true for RAID1 and RAID10.

If we get a failure writing metadata but the device doesn't
fail, it must be the last device so we re-write without
FAILFAST to improve chance of success.  We also flag the
device as LastDev so that future metadata updates don't
waste time on failfast writes.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-22 09:11:33 -08:00
NeilBrown 688834e6ae md/failfast: add failfast flag for md to be used by some personalities.
This patch just adds a 'failfast' per-device flag which can be stored
in v0.90 or v1.x metadata.
The flag is not used yet but the intent is that it can be used for
mirrored (raid1/raid10) arrays where low latency is more important
than keeping all devices on-line.

Setting the flag for a device effectively gives permission for that
device to be marked as Faulty and excluded from the array on the first
error.  The underlying driver will be directed not to retry requests
that result in failures.  There is a proviso that the device must not
be marked faulty if that would cause the array as a whole to fail, it
may only be marked Faulty if the array remains functional, but is
degraded.

Failures on read requests will cause the device to be marked
as Faulty immediately so that further reads will avoid that
device.  No attempt will be made to correct read errors by
over-writing with the correct data.

It is expected that if transient errors, such as cable unplug, are
possible, then something in user-space will revalidate failed
devices and re-add them when they appear to be working again.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-22 08:58:17 -08:00
Ming Lei 4113b88a65 bcache: debug: avoid accessing .bi_io_vec directly
Instead we use standard iterator way to do that.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22 08:57:55 -07:00
Ming Lei 3a83f46775 block: bio: pass bvec table to bio_init()
Some drivers often use external bvec table, so introduce
this helper for this case. It is always safe to access the
bio->bi_io_vec in this way for this case.

After converting to this usage, it will becomes a bit easier
to evaluate the remaining direct access to bio->bi_io_vec,
so it can help to prepare for the following multipage bvec
support.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Fixed up the new O_DIRECT cases.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22 08:57:21 -07:00
Bart Van Assche 6599c84e4c dm mpath: do not modify *__clone if blk_mq_alloc_request() fails
Purely cleanup, avoids potential for strange coding bugs.  But in
reality if __multipath_map() fails the caller has no business looking at
*__clone.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:10 -05:00
Bart Van Assche 4813577f93 dm mpath: change return type of pg_init_all_paths() from int to void
None of the callers of pg_init_all_paths() check its return value.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:09 -05:00
tang.junhui cc5bd925f1 dm mpath: add checks for priority group count to avoid invalid memory access
This avoids the potential for invalid memory access, if/when there are
no priority groups, in response to invalid arguments being sent by the
user via DM message (e.g. "switch_group", "disable_group" or
"enable_group").

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:08 -05:00
tang.junhui f97dc42128 dm mpath: add m->hw_handler_name NULL pointer check in parse_hw_handler()
Avoids false positive of no hardware handler being specified (which is
implied by a NULL m->hw_handler_name).

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:07 -05:00
Wei Yongjun bff7e067ee dm flakey: return -EINVAL on interval bounds error in flakey_ctr()
Fix to return error code -EINVAL instead of 0, as is done elsewhere in
this function.

Fixes: e80d1c805a ("dm: do not override error code returned from dm_get_device()")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:07 -05:00
Julia Lawall 1b1b58f54f dm crypt: constify crypt_iv_operations structures
The crypt_iv_operations are never modified, so declare them
as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:06 -05:00
Heinz Mauelshagen 453c2a8967 dm raid: correct error messages on old metadata validation
When target 1.9.1 gets takeover/reshape requests on devices with old superblock
format not supporting such conversions and rejects them in super_init_validation(),
it logs bogus error message (e.g. Reshape when a takeover is requested).

Whilst on it, add messages for disk adding/removing and stripe sectors
reshape requests, use the newer rs_{takeover,reshape}_requested() API,
address a raid10 false positive in checking array positions and
remove rs_set_new() because device members are already set proper.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:05 -05:00
Mike Snitzer 23cab26dfc dm cache: add missing cache device name to DMERR in set_cache_mode()
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:03 -05:00
Mike Snitzer 07d938822a dm cache metadata: remove an extra newline in DMERR and code
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:02 -05:00
Eric Biggers 21ffe552e9 dm verity: fix incorrect error message
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:01 -05:00
Mikulas Patocka 671ea6b457 dm crypt: rename crypt_setkey_allcpus to crypt_setkey
In the past, dm-crypt used per-cpu crypto context. This has been removed
in the kernel 3.15 and the crypto context is shared between all cpus. This
patch renames the function crypt_setkey_allcpus to crypt_setkey, because
there is really no activity that is done for all cpus.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:52:00 -05:00
Ondrej Kozina 265e9098ba dm crypt: mark key as invalid until properly loaded
In crypt_set_key(), if a failure occurs while replacing the old key
(e.g. tfm->setkey() fails) the key must not have DM_CRYPT_KEY_VALID flag
set.  Otherwise, the crypto layer would have an invalid key that still
has DM_CRYPT_KEY_VALID flag set.

Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:51:59 -05:00
Ming Lei 0dae7fe597 dm crypt: use bio_add_page()
Use bio_add_page(), the standard interface for adding a page to a bio,
rather than open-coding the same.

It should be noted that the 'clone' bio that is allocated using
bio_alloc_bioset(), in crypt_alloc_buffer(), does _not_ set the
bio's BIO_CLONED flag.  As such, bio_add_page()'s early return for true
bio clones (those with BIO_CLONED set) isn't applicable.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:51:58 -05:00
Ming Lei cacc7b0556 dm io: use bvec iterator helpers to implement .get_page and .next_page
Firstly we have mature bvec/bio iterator helper for iterate each
page in one bio, not necessary to reinvent a wheel to do that.

Secondly the coming multipage bvecs requires this patch.

Also add comments about the direct access to bvec table.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:51:57 -05:00
Ming Lei 4f9c74c604 dm rq: replace 'bio->bi_vcnt == 1' with !bio_multiple_segments
Avoid accessing .bi_vcnt directly, because the bio can be split from
block layer and .bi_vcnt should never have been used here.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21 09:51:57 -05:00
Song Liu 3bddb7f8f2 md/r5cache: handle FLUSH and FUA
With raid5 cache, we committing data from journal device. When
there is flush request, we need to flush journal device's cache.
This was not needed in raid5 journal, because we will flush the
journal before committing data to raid disks.

This is similar to FUA, except that we also need flush journal for
FUA. Otherwise, corruptions in earlier meta data will stop recovery
from reaching FUA data.

slightly changed the code by Shaohua

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 17:13:49 -08:00
Song Liu 5aabf7c49d md/r5cache: r5cache recovery: part 2
1. In previous patch, we:
      - add new data to r5l_recovery_ctx
      - add new functions to recovery write-back cache
   The new functions are not used in this patch, so this patch does not
   change the behavior of recovery.

2. In this patchpatch, we:
      - modify main recovery procedure r5l_recovery_log() to call new
        functions
      - remove old functions

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:28:28 -08:00
Song Liu b4c625c673 md/r5cache: r5cache recovery: part 1
Recovery of write-back cache has different logic to write-through only
cache. Specifically, for write-back cache, the recovery need to scan
through all active journal entries before flushing data out. Therefore,
large portion of the recovery logic is rewritten here.

To make the diffs cleaner, we split the rewrite as follows:

1. In this patch, we:
      - add new data to r5l_recovery_ctx
      - add new functions to recovery write-back cache
   The new functions are not used in this patch, so this patch does not
   change the behavior of recovery.

2. In next patch, we:
      - modify main recovery procedure r5l_recovery_log() to call new
        functions
      - remove old functions

With cache feature, there are 2 different scenarios of recovery:
1. Data-Parity stripe: a stripe with complete parity in journal.
2. Data-Only stripe: a stripe with only data in journal (or partial
   parity).

The code differentiate Data-Parity stripe from Data-Only stripe with
flag STRIPE_R5C_CACHING.

For Data-Parity stripes, we use the same procedure as raid5 journal,
where all the data and parity are replayed to the RAID devices.

For Data-Only strips, we need to finish complete calculate parity and
finish the full reconstruct write or RMW write. For simplicity, in
the recovery, we load the stripe to stripe cache. Once the array is
started, the stripe cache state machine will handle these stripes
through normal write path.

r5c_recovery_flush_log contains the main procedure of recovery. The
recovery code first scans through the journal and loads data to
stripe cache. The code keeps tracks of all these stripes in a list
(use sh->lru and ctx->cached_list), stripes in the list are
organized in the order of its first appearance on the journal.
During the scan, the recovery code assesses each stripe as
Data-Parity or Data-Only.

During scan, the array may run out of stripe cache. In these cases,
the recovery code will also call raid5_set_cache_size to increase
stripe cache size. If the array still runs out of stripe cache
because there isn't enough memory, the array will not assemble.

At the end of scan, the recovery code replays all Data-Parity
stripes, and sets proper states for Data-Only stripes. The recovery
code also increases seq number by 10 and rewrites all Data-Only
stripes to journal. This is to avoid confusion after repeated
crashes. More details is explained in raid5-cache.c before
r5c_recovery_rewrite_data_only_stripes().

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:28:14 -08:00
Song Liu 9ed988f5dc md/r5cache: refactoring journal recovery code
1. rename r5l_read_meta_block() as r5l_recovery_read_meta_block();
2. pull the code that initialize r5l_meta_block from
   r5l_log_write_empty_meta_block() to a separate function
   r5l_recovery_create_empty_meta_block(), so that we can reuse this
   piece of code.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:27:45 -08:00
Song Liu 2c7da14b90 md/r5cache: sysfs entry journal_mode
With write cache, journal_mode is the knob to switch between
write-back and write-through.

Below is an example:

root@virt-test:~/# cat /sys/block/md0/md/journal_mode
[write-through] write-back
root@virt-test:~/# echo write-back > /sys/block/md0/md/journal_mode
root@virt-test:~/# cat /sys/block/md0/md/journal_mode
write-through [write-back]

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:27:24 -08:00
Song Liu a39f7afde3 md/r5cache: write-out phase and reclaim support
There are two limited resources, stripe cache and journal disk space.
For better performance, we priotize reclaim of full stripe writes.
To free up more journal space, we free earliest data on the journal.

In current implementation, reclaim happens when:
1. Periodically (every R5C_RECLAIM_WAKEUP_INTERVAL, 30 seconds) reclaim
   if there is no reclaim in the past 5 seconds.
2. when there are R5C_FULL_STRIPE_FLUSH_BATCH (256) cached full stripes,
   or cached stripes is enough for a full stripe (chunk size / 4k)
   (r5c_check_cached_full_stripe)
3. when there is pressure on stripe cache (r5c_check_stripe_cache_usage)
4. when there is pressure on journal space (r5l_write_stripe, r5c_cache_data)

r5c_do_reclaim() contains new logic of reclaim.

For stripe cache:

When stripe cache pressure is high (more than 3/4 stripes are cached,
or there is empty inactive lists), flush all full stripe. If fewer
than R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2) full stripes
are flushed, flush some paritial stripes. When stripe cache pressure
is moderate (1/2 to 3/4 of stripes are cached), flush all full stripes.

For log space:

To avoid deadlock due to log space, we need to reserve enough space
to flush cached data. The size of required log space depends on total
number of cached stripes (stripe_in_journal_count). In current
implementation, the writing-out phase automatically include pending
data writes with parity writes (similar to write through case).
Therefore, we need up to (conf->raid_disks + 1) pages for each cached
stripe (1 page for meta data, raid_disks pages for all data and
parity). r5c_log_required_to_flush_cache() calculates log space
required to flush cache. In the following, we refer to the space
calculated by r5c_log_required_to_flush_cache() as
reclaim_required_space.

Two flags are added to r5conf->cache_state: R5C_LOG_TIGHT and
R5C_LOG_CRITICAL. R5C_LOG_TIGHT is set when free space on the log
device is less than 3x of reclaim_required_space. R5C_LOG_CRITICAL
is set when free space on the log device is less than 2x of
reclaim_required_space.

r5c_cache keeps all data in cache (not fully committed to RAID) in
a list (stripe_in_journal_list). These stripes are in the order of their
first appearance on the journal. So the log tail (last_checkpoint)
should point to the journal_start of the first item in the list.

When R5C_LOG_TIGHT is set, r5l_reclaim_thread starts flushing out
stripes at the head of stripe_in_journal. When R5C_LOG_CRITICAL is
set, the state machine only writes data that are already in the
log device (in stripe_in_journal_list).

This patch includes a fix to improve performance by
Shaohua Li <shli@fb.com>.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:26:48 -08:00
Song Liu 1e6d690b93 md/r5cache: caching phase of r5cache
As described in previous patch, write back cache operates in two
phases: caching and writing-out. The caching phase works as:
1. write data to journal
   (r5c_handle_stripe_dirtying, r5c_cache_data)
2. call bio_endio
   (r5c_handle_data_cached, r5c_return_dev_pending_writes).

Then the writing-out phase is as:
1. Mark the stripe as write-out (r5c_make_stripe_write_out)
2. Calcualte parity (reconstruct or RMW)
3. Write parity (and maybe some other data) to journal device
4. Write data and parity to RAID disks

This patch implements caching phase. The cache is integrated with
stripe cache of raid456. It leverages code of r5l_log to write
data to journal device.

Writing-out phase of the cache is implemented in the next patch.

With r5cache, write operation does not wait for parity calculation
and write out, so the write latency is lower (1 write to journal
device vs. read and then write to raid disks). Also, r5cache will
reduce RAID overhead (multipile IO due to read-modify-write of
parity) and provide more opportunities of full stripe writes.

This patch adds 2 flags to stripe_head.state:
 - STRIPE_R5C_PARTIAL_STRIPE,
 - STRIPE_R5C_FULL_STRIPE,

Instead of inactive_list, stripes with cached data are tracked in
r5conf->r5c_full_stripe_list and r5conf->r5c_partial_stripe_list.
STRIPE_R5C_FULL_STRIPE and STRIPE_R5C_PARTIAL_STRIPE are flags for
stripes in these lists. Note: stripes in r5c_full/partial_stripe_list
are not considered as "active".

For RMW, the code allocates an extra page for each data block
being updated.  This is stored in r5dev->orig_page and the old data
is read into it.  Then the prexor calculation subtracts ->orig_page
from the parity block, and the reconstruct calculation adds the
->page data back into the parity block.

r5cache naturally excludes SkipCopy. When the array has write back
cache, async_copy_data() will not skip copy.

There are some known limitations of the cache implementation:

1. Write cache only covers full page writes (R5_OVERWRITE). Writes
   of smaller granularity are write through.
2. Only one log io (sh->log_io) for each stripe at anytime. Later
   writes for the same stripe have to wait. This can be improved by
   moving log_io to r5dev.
3. With writeback cache, read path must enter state machine, which
   is a significant bottleneck for some workloads.
4. There is no per stripe checkpoint (with r5l_payload_flush) in
   the log, so recovery code has to replay more than necessary data
   (sometimes all the log from last_checkpoint). This reduces
   availability of the array.

This patch includes a fix proposed by ZhengYuan Liu
<liuzhengyuan@kylinos.cn>

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:26:30 -08:00
Song Liu 2ded370373 md/r5cache: State machine for raid5-cache write back mode
This patch adds state machine for raid5-cache. With log device, the
raid456 array could operate in two different modes (r5c_journal_mode):
  - write-back (R5C_MODE_WRITE_BACK)
  - write-through (R5C_MODE_WRITE_THROUGH)

Existing code of raid5-cache only has write-through mode. For write-back
cache, it is necessary to extend the state machine.

With write-back cache, every stripe could operate in two different
phases:
  - caching
  - writing-out

In caching phase, the stripe handles writes as:
  - write to journal
  - return IO

In writing-out phase, the stripe behaviors as a stripe in write through
mode R5C_MODE_WRITE_THROUGH.

STRIPE_R5C_CACHING is added to sh->state to differentiate caching and
writing-out phase.

Please note: this is a "no-op" patch for raid5-cache write-through
mode.

The following detailed explanation is copied from the raid5-cache.c:

/*
 * raid5 cache state machine
 *
 * With rhe RAID cache, each stripe works in two phases:
 *      - caching phase
 *      - writing-out phase
 *
 * These two phases are controlled by bit STRIPE_R5C_CACHING:
 *   if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
 *   if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
 *
 * When there is no journal, or the journal is in write-through mode,
 * the stripe is always in writing-out phase.
 *
 * For write-back journal, the stripe is sent to caching phase on write
 * (r5c_handle_stripe_dirtying). r5c_make_stripe_write_out() kicks off
 * the write-out phase by clearing STRIPE_R5C_CACHING.
 *
 * Stripes in caching phase do not write the raid disks. Instead, all
 * writes are committed from the log device. Therefore, a stripe in
 * caching phase handles writes as:
 *      - write to log device
 *      - return IO
 *
 * Stripes in writing-out phase handle writes as:
 *      - calculate parity
 *      - write pending data and parity to journal
 *      - write data and parity to raid disks
 *      - return IO for pending writes
 */

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:26:07 -08:00
Song Liu 937621c36e md/r5cache: move some code to raid5.h
Move some define and inline functions to raid5.h, so they can be
used in raid5-cache.c

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:25:40 -08:00
Song Liu c757ec95c2 md/r5cache: Check array size in r5l_init_log
Currently, r5l_write_stripe checks meta size for each stripe write,
which is not necessary.

With this patch, r5l_init_log checks maximal meta size of the array,
which is (r5l_meta_block + raid_disks x r5l_payload_data_parity).
If this is too big to fit in one page, r5l_init_log aborts.

With current meta data, r5l_log support raid_disks up to 203.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 13:24:46 -08:00
Shaohua Li 504634f60f md: add blktrace event for writes to superblock
superblock write is an expensive operation. With raid5-cache, it can be called
regularly. Tracing to help performance debug.

Signed-off-by: Shaohua Li <shli@fb.com>
Cc: NeilBrown <neilb@suse.com>
2016-11-18 09:47:57 -08:00
NeilBrown 578b54ade8 md/raid1, raid10: add blktrace records when IO is delayed
Both raid1 and raid10 will sometimes delay handling an IO request,
such as when resync is happening or there are too many requests queued.

Add some blktrace messsages so we can see when that is happening when
looking for performance artefacts.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 09:35:37 -08:00
NeilBrown 581dbd94da md/bitmap: add blktrace event for writes to the bitmap
We trace wheneven bitmap_unplug() finds that it needs to write
to the bitmap, or when bitmap_daemon_work() find there is work
to do.

This makes it easier to correlate bitmap updates with data writes.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 09:34:45 -08:00
NeilBrown 109e376530 md: add block tracing for bio_remapping
The block tracing infrastructure (accessed with blktrace/blkparse)
supports the tracing of mapping bios from one device to another.
This is currently used when a bio in a partition is mapped to the
whole device, when bios are mapped by dm, and for mapping in md/raid5.
Other md personalities do not include this tracing yet, so add it.

When a read-error is detected we redirect the request to a different device.
This could justifiably be seen as a new mapping for the originial bio,
or a secondary mapping for the bio that errors.  This patch uses
the second option.

When md is used under dm-raid, the mappings are not traced as we do
not have access to the block device number of the parent.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-18 09:32:50 -08:00
Shaohua Li 354b445b5f raid5-cache: fix lockdep warning
lockdep reports warning of the rcu_dereference usage. Using normal rdev
access pattern to avoid the warning.

Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-17 11:30:27 -08:00
Bart Van Assche d15bb3a646 dm rq: fix a race condition in rq_completed()
It is required to hold the queue lock when calling blk_run_queue_async()
to avoid that a race between blk_run_queue_async() and
blk_cleanup_queue() is triggered.

Cc: stable@vger.kernel.org
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-14 15:17:50 -05:00
Joe Thornber 2e8ed71102 dm block manager: make block locking optional
The block manager's locking is useful for catching cycles that may
result from certain btree metadata corruption.  But in general it serves
as a developer tool to catch bugs in code.  Unless you're finding that
DM thin provisioning is hanging due to infinite loops within the block
manager's access to btree nodes you can safely disable this feature.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de> # do/while(0) macro fix
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-14 15:17:47 -05:00
NeilBrown 6119e6792b md: remove md_super_wait() call after bitmap_flush()
bitmap_flush() finishes with bitmap_update_sb(), and that finishes
with write_page(..., 1), so write_page() will wait for all writes
to complete.  So there is no point calling md_super_wait()
immediately afterwards.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-09 17:14:28 -08:00
NeilBrown be306c2989 md: define mddev flags, recovery flags and r1bio state bits using enums
This is less error prone than using individual #defines.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-09 12:53:52 -08:00
NeilBrown f2c771a655 md/raid1: fix: IO can block resync indefinitely
While performing a resync/recovery, raid1 divides the
array space into three regions:
 - before the resync
 - at or shortly after the resync point
 - much further ahead of the resync point.

Write requests to the first or third do not need to wait.  Write
requests to the middle region do need to wait if resync requests are
pending.

If there are any active write requests in the middle region, resync
will wait for them.

Due to an accounting error, there is a small range of addresses,
between conf->next_resync and conf->start_next_window, where write
requests will *not* be blocked, but *will* be counted in the middle
region.  This can effectively block resync indefinitely if filesystem
writes happen repeatedly to this region.

As ->next_window_requests is incremented when the sector is after
  conf->start_next_window + NEXT_NORMALIO_DISTANCE
the same boundary should be used for determining when write requests
should wait.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-09 12:53:24 -08:00
NeilBrown 85c9ccd4f0 md/bitmap: Don't write bitmap while earlier writes might be in-flight
As we don't wait for writes to complete in bitmap_daemon_work, they
could still be in-flight when bitmap_unplug writes again.  Or when
bitmap_daemon_work tries to write again.
This can be confusing and could risk the wrong data being written last.

So make sure we wait for old writes to complete before new writes start.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:23 -08:00
NeilBrown a9ae93c8cc md/raid10: abort delayed writes when device fails.
When writing to an array with a bitmap enabled, the writes are grouped
in batches which are preceded by an update to the bitmap.

It is quite likely if that a drive develops a problem which is not
media related, that the bitmap write will be the first to report an
error and cause the device to be marked faulty (as the bitmap write is
at the start of a batch).

In this case, there is point submiting the subsequent writes to the
failed device - that just wastes times.

So re-check the Faulty state of a device before submitting a
delayed write.

This requires that we keep the 'rdev', rather than the 'bdev' in the
bio, then swap in the bdev just before final submission.

Reported-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:23 -08:00
NeilBrown 5e2c7a3611 md/raid1: abort delayed writes when device fails.
When writing to an array with a bitmap enabled, the writes are grouped
in batches which are preceded by an update to the bitmap.

It is quite likely if that a drive develops a problem which is not
media related, that the bitmap write will be the first to report an
error and cause the device to be marked faulty (as the bitmap write is
at the start of a batch).

In this case, there is point submiting the subsequent writes to the
failed device - that just wastes times.

So re-check the Faulty state of a device before submitting a
delayed write.

This requires that we keep the 'rdev', rather than the 'bdev' in the
bio, then swap in the bdev just before final submission.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:23 -08:00
NeilBrown 060b0689f5 md: perform async updates for metadata where possible.
When adding devices to, or removing device from, an array we need to
update the metadata.  However we don't need to do it synchronously as
data integrity doesn't depend on these changes being recorded
instantly.  So avoid the synchronous call to md_update_sb and just set
a flag so that the thread will do it.

This can reduce the number of updates performed when lots of devices
are being added or removed.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:23 -08:00
JackieLiu 3fd880af41 raid5-cache: restrict the use area of the log_offset variable
We can calculate this offset by using ctx->meta_total_blocks,
without passing in from the function

Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:22 -08:00
NeilBrown cc6167b4f3 md/raid5: change printk() to pr_*()
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:22 -08:00
NeilBrown 08464e0926 md/raid10: change printk() to pr_*()
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:22 -08:00
NeilBrown 1d41c216fe md/raid1: change printk() to pr_*()
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:22 -08:00
NeilBrown 766038846e md/raid0: replace printk() with pr_*()
This makes md/raid0 much less verbose as the messages about
the array geometry are now pr_debug()

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:22 -08:00
NeilBrown 7279694da4 md/multipath: replace printk() with pr_*()
Also remove all messages about memory allocation failure.
page_alloc() reports those.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:22 -08:00
NeilBrown a2e202afa6 md/linear: replace printk() with pr_*()
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
NeilBrown ec0cc22685 md/bitmap: change all printk() to pr_*()
Follow err/warn distinction introduced in md.c
Join multi-part strings into single string.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
NeilBrown 9d48739ef1 md: change all printk() to pr_err() or pr_warn() etc.
1/ using pr_debug() for a number of messages reduces the noise of
   md, but still allows them to be enabled when needed.
2/ try to be consistent in the usage of pr_err() and pr_warn(), and
   document the intention
3/ When strings have been split onto multiple lines, rejoin into
   a single string.
   The cost of having lines > 80 chars is less than the cost of not
   being able to easily search for a particular message.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
NeilBrown 7f0f0d87fa md: fix some issues with alloc_disk_sb()
1/ don't print a warning if allocation fails.
 page_alloc() does that already.
2/ always check return status for error.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
Guoqing Jiang cbb3873236 md/bitmap: call bitmap_file_unmap once bitmap_storage_alloc returns -ENOMEM
It is possible that bitmap_storage_alloc could return -ENOMEM,
and some member inside store could be allocated such as filemap.

To avoid memory leak, we need to call bitmap_file_unmap to free
those members in the bitmap_resize.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
Tomasz Majchrzak 7adb072ca8 raid5: revert commit 11367799f3
Revert commit 11367799f3 ("md: Prevent IO hold during accessing to faulty
raid5 array") as it doesn't comply with commit c3cce6cda1 ("md/raid5:
ensure device failure recorded before write request returns."). That change
is not required anymore as the problem is resolved by commit 16f889499a
("md: report 'write_pending' state when array in sync") - read request is
stuck as array state is not reported correctly via sysfs attribute.

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
Tomasz Majchrzak 91a6c4aded md: wake up personality thread after array state update
When raid1/raid10 array fails to write to one of the drives, the request
is added to bio_end_io_list and finished by personality thread. The
thread doesn't handle it as long as MD_CHANGE_PENDING flag is set. In
case of external metadata this flag is cleared, however the thread is
not woken up. It causes request to be blocked for few seconds (until
another action on the array wakes up the thread) or to get stuck
indefinitely.

Wake up personality thread once MD_CHANGE_PENDING has been cleared.
Moving 'restart_array' call after the flag is cleared it not a solution
because in read-write mode the call doesn't wake up the thread.

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:21 -08:00
Tomasz Majchrzak dcbcb48650 md: don't fail an array if there are unacknowledged bad blocks
If external metadata handler supports bad blocks and unacknowledged bad
blocks are present, don't report disk via sysfs as faulty. Such
situation can be still handled so disk just has to be blocked for a
moment. It makes it consistent with kernel state as corresponding rdev
flag is also not set.

When the disk in being unblocked there are few cases:
1. Disk has been in blocked and faulty state, it is being unblocked but
it still remains in faulty state. Metadata handler will remove it from
array in the next call.
2. There is no bad block support in external metadata handler and bad
blocks are present - put the disk in blocked and faulty state (see
case 1).
3. There is bad block support in external metadata handler and all bad
blocks are acknowledged - clear all flags, continue.
4. There is bad block support in external metadata handler but there are
still unacknowledged bad blocks - clear all flags, continue. It is fine
to clear Blocked flag because it was probably not set anyway (if it was
it is case 1). BlockedBadBlocks flag can also be cleared because the
request waiting for it will set it again when it finds out that some bad
block is still not acknowledged. Recovery is not necessary but there are
no problems if the flag is set. Sysfs rdev state is still reported as
blocked (due to unacknowledged bad blocks) so metadata handler will
process remaining bad blocks and unblock disk again.

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:20 -08:00
Tomasz Majchrzak 35b785f769 md: add bad block support for external metadata
Add new rdev flag which external metadata handler can use to switch
on/off bad block support. If new bad block is encountered, notify it via
rdev 'unacknowledged_bad_blocks' sysfs file. If bad block has been
cleared, notify update to rdev 'bad_blocks' sysfs file.

When bad blocks support is being removed, just clear rdev flag. It is
not necessary to reset badblocks->shift field. If there are bad blocks
cleared or added at the same time, it is ok for those changes to be
applied to the structure. The array is in blocked state and the drive
which cannot handle bad blocks any more will be removed from the array
before it is unlocked.

Simplify state_show function by adding a separator at the end of each
string and overwrite last separator with new line.

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-11-07 15:08:20 -08:00
Linus Torvalds 6c286e812d Merge tag 'md/4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD fixes from Shaohua Li:
 "There are several bug fixes queued:

   - fix raid5-cache recovery bugs

   - fix discard IO error handling for raid1/10

   - fix array sync writes bogus position to superblock

   - fix IO error handling for raid array with external metadata"

* tag 'md/4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md: be careful not lot leak internal curr_resync value into metadata. -- (all)
  raid1: handle read error also in readonly mode
  raid5-cache: correct condition for empty metadata write
  md: report 'write_pending' state when array in sync
  md/raid5: write an empty meta-block when creating log super-block
  md/raid5: initialize next_checkpoint field before use
  RAID10: ignore discard error
  RAID1: ignore discard error
2016-11-05 11:34:07 -07:00
Bart Van Assche 7b17c2f729 dm: Fix a race condition related to stopping and starting queues
Ensure that all ongoing dm_mq_queue_rq() and dm_mq_requeue_request()
calls have stopped before setting the "queue stopped" flag. This
allows to remove the "queue stopped" test from dm_mq_queue_rq() and
dm_mq_requeue_request(). This patch fixes a race condition because
dm_mq_queue_rq() is called without holding the queue lock and hence
BLK_MQ_S_STOPPED can be set at any time while dm_mq_queue_rq() is
in progress. This patch prevents that the following hang occurs
sporadically when using dm-mq:

INFO: task systemd-udevd:10111 blocked for more than 480 seconds.
Call Trace:
 [<ffffffff8161f397>] schedule+0x37/0x90
 [<ffffffff816239ef>] schedule_timeout+0x27f/0x470
 [<ffffffff8161e76f>] io_schedule_timeout+0x9f/0x110
 [<ffffffff8161fb36>] bit_wait_io+0x16/0x60
 [<ffffffff8161f929>] __wait_on_bit_lock+0x49/0xa0
 [<ffffffff8114fe69>] __lock_page+0xb9/0xc0
 [<ffffffff81165d90>] truncate_inode_pages_range+0x3e0/0x760
 [<ffffffff81166120>] truncate_inode_pages+0x10/0x20
 [<ffffffff81212a20>] kill_bdev+0x30/0x40
 [<ffffffff81213d41>] __blkdev_put+0x71/0x360
 [<ffffffff81214079>] blkdev_put+0x49/0x170
 [<ffffffff812141c0>] blkdev_close+0x20/0x30
 [<ffffffff811d48e8>] __fput+0xe8/0x1f0
 [<ffffffff811d4a29>] ____fput+0x9/0x10
 [<ffffffff810842d3>] task_work_run+0x83/0xb0
 [<ffffffff8106606e>] do_exit+0x3ee/0xc40
 [<ffffffff8106694b>] do_group_exit+0x4b/0xc0
 [<ffffffff81073d9a>] get_signal+0x2ca/0x940
 [<ffffffff8101bf43>] do_signal+0x23/0x660
 [<ffffffff810022b3>] exit_to_usermode_loop+0x73/0xb0
 [<ffffffff81002cb0>] syscall_return_slowpath+0xb0/0xc0
 [<ffffffff81624e33>] entry_SYSCALL_64_fastpath+0xa6/0xa8

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche f0d33ab76c dm: Use BLK_MQ_S_STOPPED instead of QUEUE_FLAG_STOPPED in blk-mq code
Instead of manipulating both QUEUE_FLAG_STOPPED and BLK_MQ_S_STOPPED
in the dm start and stop queue functions, only manipulate the latter
flag. Change blk_queue_stopped() tests into blk_mq_queue_stopped().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche 2b053aca76 blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()
Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
are followed by kicking the requeue list. Hence add an argument to
these two functions that allows to kick the requeue list. This was
proposed by Christoph Hellwig.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche 9b7dd572cc blk-mq: Remove blk_mq_cancel_requeue_work()
Since blk_mq_requeue_work() no longer restarts stopped queues
canceling requeue work is no longer needed to prevent that a
stopped queue would be restarted. Hence remove this function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche 52d7f1b5c2 blk-mq: Avoid that requeueing starts stopped queues
Since blk_mq_requeue_work() starts stopped queues and since
execution of this function can be scheduled after a queue has
been stopped it is not possible to stop queues without using
an additional state variable to track whether or not the queue
has been stopped. Hence modify blk_mq_requeue_work() such that it
does not start stopped queues. My conclusion after a review of
the blk_mq_stop_hw_queues() and blk_mq_{delay_,}kick_requeue_list()
callers is as follows:
* In the dm driver starting and stopping queues should only happen
  if __dm_suspend() or __dm_resume() is called and not if the
  requeue list is processed.
* In the SCSI core queue stopping and starting should only be
  performed by the scsi_internal_device_block() and
  scsi_internal_device_unblock() functions but not by any other
  function. Although the blk_mq_stop_hw_queue() call in
  scsi_queue_rq() may help to reduce CPU load if a LLD queue is
  full, figuring out whether or not a queue should be restarted
  when requeueing a command would require to introduce additional
  locking in scsi_mq_requeue_cmd() to avoid a race with
  scsi_internal_device_block(). Avoid this complexity by removing
  the blk_mq_stop_hw_queue() call from scsi_queue_rq().
* In the NVMe core only the functions that call
  blk_mq_start_stopped_hw_queues() explicitly should start stopped
  queues.
* A blk_mq_start_stopped_hwqueues() call must be added in the
  xen-blkfront driver in its blkif_recover() function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Christoph Hellwig 70fd76140a block,fs: use REQ_* flags directly
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly.  Where applicable this also drops usage of the
bio_set_op_attrs wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
Christoph Hellwig 83b5df67c5 bcache: use op_is_sync to check for synchronous requests
(and remove one layer of masking for the op_is_write call next to it).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
NeilBrown 1217e1d199 md: be careful not lot leak internal curr_resync value into metadata. -- (all)
mddev->curr_resync usually records where the current resync is up to,
but during the starting phase it has some "magic" values.

 1 - means that the array is trying to start a resync, but has yielded
     to another array which shares physical devices, and also needs to
     start a resync
 2 - means the array is trying to start resync, but has found another
     array which shares physical devices and has already started resync.

 3 - means that resync has commensed, but it is possible that nothing
     has actually been resynced yet.

It is important that this value not be visible to user-space and
particularly that it doesn't get written to the metadata, as the
resync or recovery checkpoint.  In part, this is because it may be
slightly higher than the correct value, though this is very rare.
In part, because it is not a multiple of 4K, and some devices only
support 4K aligned accesses.

There are two places where this value is propagates into either
->curr_resync_completed or ->recovery_cp or ->recovery_offset.
These currently avoid the propagation of values 1 and 3, but will
allow 3 to leak through.

Change them to only propagate the value if it is > 3.

As this can cause an array to fail, the patch is suitable for -stable.

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: Viswesh <viswesh.vichu@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-28 22:04:05 -07:00
Tomasz Majchrzak 7449f699b2 raid1: handle read error also in readonly mode
If write is the first operation on a disk and it happens not to be
aligned to page size, block layer sends read request first. If read
operation fails, the disk is set as failed as no attempt to fix the
error is made because array is in auto-readonly mode. Similarily, the
disk is set as failed for read-only array.

Take the same approach as in raid10. Don't fail the disk if array is in
readonly or auto-readonly mode. Try to redirect the request first and if
unsuccessful, return a read error.

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-28 22:04:04 -07:00
Shaohua Li 9a8b27fac5 raid5-cache: correct condition for empty metadata write
As long as we recover one metadata block, we should write the empty metadata
write. The original code could make recovery corrupted if only one meta is
valid.

Reported-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-28 22:04:03 -07:00
Linus Torvalds e0f3e6a7cc - A couple DM raid and DM mirror fixes
- A couple .request_fn request-based DM NULL pointer fixes
 
 - A fix for a DM target reference count leak, on target load error, that
   prevented associated DM target kernel module(s) from being removed
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Merge tag 'dm-4.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a couple DM raid and DM mirror fixes

 - a couple .request_fn request-based DM NULL pointer fixes

 - a fix for a DM target reference count leak, on target load error,
   that prevented associated DM target kernel module(s) from being
   removed

* tag 'dm-4.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm table: fix missing dm_put_target_type() in dm_table_add_target()
  dm rq: clear kworker_task if kthread_run() returned an error
  dm: free io_barrier after blk_cleanup_queue call
  dm raid: fix activation of existing raid4/10 devices
  dm mirror: use all available legs on multiple failures
  dm mirror: fix read error on recovery after default leg failure
  dm raid: fix compat_features validation
2016-10-28 09:27:58 -07:00
Christoph Hellwig ef295ecf09 block: better op and flags encoding
Now that we don't need the common flags to overflow outside the range
of a 32-bit type we can encode them the same way for both the bio and
request fields.  This in addition allows us to place the operation
first (and make some room for more ops while we're at it) and to
stop having to shift around the operation values.

In addition this allows passing around only one value in the block layer
instead of two (and eventuall also in the file systems, but we can do
that later) and thus clean up a lot of code.

Last but not least this allows decreasing the size of the cmd_flags
field in struct request to 32-bits.  Various functions passing this
value could also be updated, but I'd like to avoid the churn for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:48:16 -06:00
Christoph Hellwig e806402130 block: split out request-only flags into a new namespace
A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests.  It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:45:17 -06:00
Tomasz Majchrzak 16f889499a md: report 'write_pending' state when array in sync
If there is a bad block on a disk and there is a recovery performed from
this disk, the same bad block is reported for a new disk. It involves
setting MD_CHANGE_PENDING flag in rdev_set_badblocks. For external
metadata this flag is not being cleared as array state is reported as
'clean'. The read request to bad block in RAID5 array gets stuck as it
is waiting for a flag to be cleared - as per commit c3cce6cda1
("md/raid5: ensure device failure recorded before write request
returns.").

The meaning of MD_CHANGE_PENDING and MD_CHANGE_CLEAN flags has been
clarified in commit 070dc6dd71 ("md: resolve confusion of
MD_CHANGE_CLEAN"), however MD_CHANGE_PENDING flag has been used in
personality error handlers since and it doesn't fully comply with
initial purpose. It was supposed to notify that write request is about
to start, however now it is also used to request metadata update.
Initially (in md_allow_write, md_write_start) MD_CHANGE_PENDING flag has
been set and in_sync has been set to 0 at the same time. Error handlers
just set the flag without modifying in_sync value. Sysfs array state is
a single value so now it reports 'clean' when MD_CHANGE_PENDING flag is
set and in_sync is set to 1. Userspace has no idea it is expected to
take some action.

Swap the order that array state is checked so 'write_pending' is
reported ahead of 'clean' ('write_pending' is a misleading name but it
is too late to rename it now).

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-24 15:28:19 -07:00
Zhengyuan Liu 56056c2e7d md/raid5: write an empty meta-block when creating log super-block
If superblock points to an invalid meta block, r5l_load_log will set
create_super with true and create an new superblock, this runtime path
would always happen if we do no writing I/O to this array since it was
created. Writing an empty meta block could avoid this unnecessary
action at the first time we created log superblock.

Another reason is for the corretness of log recovery. Currently we have
bellow code to guarantee log revocery to be correct.

        if (ctx.seq > log->last_cp_seq + 1) {
                int ret;

                ret = r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq + 10);
                if (ret)
                        return ret;
                log->seq = ctx.seq + 11;
                log->log_start = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
                r5l_write_super(log, ctx.pos);
        } else {
                log->log_start = ctx.pos;
                log->seq = ctx.seq;
        }

If we just created a array with a journal device, log->log_start and
log->last_checkpoint should all be 0, then we write three meta block
which are valid except mid one and supposed crash happened. The ctx.seq
would equal to log->last_cp_seq + 1 and log->log_start would be set to
position of mid invalid meta block after we did a recovery, this will
lead to problems which could be avoided with this patch.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-24 15:28:18 -07:00
Zhengyuan Liu 28cd88e2b4 md/raid5: initialize next_checkpoint field before use
No initial operation was done to this field when we
load/recovery the log, it got assignment only when IO
to raid disk was finished. So r5l_quiesce may use wrong
next_checkpoint to reclaim log space, that would make
reclaimable space calculation confused.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-24 15:28:18 -07:00
Shaohua Li 579ed34f7b RAID10: ignore discard error
This is the counterpart of raid10 fix. If a write error occurs, raid10
will try to rewrite the bio in small chunk size. If the rewrite fails,
raid10 will record the error in bad block. narrow_write_error will
always use WRITE for the bio, but actually it could be a discard. Since
discard bio hasn't payload, write the bio will cause different issues.
But discard error isn't fatal, we can safely ignore it. This is what
this patch does.

This issue should exist since discard is added, but only exposed with
recent arbitrary bio size feature.

Cc: Sitsofe Wheeler <sitsofe@gmail.com>
Cc: stable@vger.kernel.org (v3.6)
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-24 15:28:17 -07:00
Shaohua Li e3f948cd32 RAID1: ignore discard error
If a write error occurs, raid1 will try to rewrite the bio in small
chunk size. If the rewrite fails, raid1 will record the error in bad
block. narrow_write_error will always use WRITE for the bio, but
actually it could be a discard. Since discard bio hasn't payload, write
the bio will cause different issues. But discard error isn't fatal, we
can safely ignore it. This is what this patch does.

This issue should exist since discard is added, but only exposed with
recent arbitrary bio size feature.

Reported-and-tested-by: Sitsofe Wheeler <sitsofe@gmail.com>
Cc: stable@vger.kernel.org (v3.6)
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-24 15:28:17 -07:00
tang.junhui dafa724bf5 dm table: fix missing dm_put_target_type() in dm_table_add_target()
dm_get_target_type() was previously called so any error returned from
dm_table_add_target() must first call dm_put_target_type().  Otherwise
the DM target module's reference count will leak and the associated
kernel module will be unable to be removed.

Also, leverage the fact that r is already -EINVAL and remove an extra
newline.

Fixes: 36a0456 ("dm table: add immutable feature")
Fixes: cc6cbe1 ("dm table: add always writeable feature")
Fixes: 3791e2f ("dm table: add singleton feature")
Cc: stable@vger.kernel.org # 3.2+
Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-24 11:17:46 -04:00
Mike Snitzer 937fa62e8a dm rq: clear kworker_task if kthread_run() returned an error
cleanup_mapped_device() calls kthread_stop() if kworker_task is
non-NULL.  Currently the assigned value could be a valid task struct or
an error code (e.g -ENOMEM).  Reset md->kworker_task to NULL if
kthread_run() returned an erorr.

Fixes: 7193a9defc ("dm rq: check kthread_run return for .request_fn request-based DM")
Cc: stable@vger.kernel.org # 4.8
Reported-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-18 14:02:04 -04:00
Tahsin Erdogan d09960b003 dm: free io_barrier after blk_cleanup_queue call
dm_old_request_fn() has paths that access md->io_barrier.  The party
destroying io_barrier should ensure that no future execution of
dm_old_request_fn() is possible.  Move io_barrier destruction to below
blk_cleanup_queue() to ensure this and avoid a NULL pointer crash during
request-based DM device shutdown.

Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-18 12:02:08 -04:00
Heinz Mauelshagen b052b07c39 dm raid: fix activation of existing raid4/10 devices
dm-raid 1.9.0 fails to activate existing RAID4/10 devices that have the
old superblock format (which does not have takeover/reshaping support
that was added via commit 33e53f0685).

Fix validation path for old superblocks by reverting to the old raid4
layout and basing checks on mddev->new_{level,layout,...} members in
super_init_validation().

Cc: stable@vger.kernel.org # 4.8
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-17 16:41:31 -04:00
Heinz Mauelshagen 12a7cf5ba6 dm mirror: use all available legs on multiple failures
When any leg(s) have failed, any read will cause a new operational
default leg to be selected and the read is resubmitted to it.  If that
new default leg fails the read too, no other still accessible legs are
used to resubmit the read again -- thus failing the io.

Fix by allowing the read to get resubmitted until all operational legs
have been exhausted.  Also, remove any details.bi_dev use as a flag.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-14 11:55:17 -04:00
Heinz Mauelshagen dcb2ff5641 dm mirror: fix read error on recovery after default leg failure
If a default leg has failed, any read will cause a new operational
default leg to be selected and the read is resubmitted.  But until now
the read will return failure even though it was successful due to
resubmission.  The reason for this is bio->bi_error was not being
cleared before resubmitting the bio.

Fix by clearing bio->bi_error before resubmission.

Fixes: 4246a0b63b ("block: add a bi_error field to struct bio")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-14 11:54:10 -04:00
Petr Mladek 3989144f86 kthread: kthread worker API cleanup
A good practice is to prefix the names of functions by the name
of the subsystem.

The kthread worker API is a mix of classic kthreads and workqueues.  Each
worker has a dedicated kthread.  It runs a generic function that process
queued works.  It is implemented as part of the kthread subsystem.

This patch renames the existing kthread worker API to use
the corresponding name from the workqueues API prefixed by
kthread_:

__init_kthread_worker()		-> __kthread_init_worker()
init_kthread_worker()		-> kthread_init_worker()
init_kthread_work()		-> kthread_init_work()
insert_kthread_work()		-> kthread_insert_work()
queue_kthread_work()		-> kthread_queue_work()
flush_kthread_work()		-> kthread_flush_work()
flush_kthread_worker()		-> kthread_flush_worker()

Note that the names of DEFINE_KTHREAD_WORK*() macros stay
as they are. It is common that the "DEFINE_" prefix has
precedence over the subsystem names.

Note that INIT() macros and init() functions use different
naming scheme. There is no good solution. There are several
reasons for this solution:

  + "init" in the function names stands for the verb "initialize"
    aka "initialize worker". While "INIT" in the macro names
    stands for the noun "INITIALIZER" aka "worker initializer".

  + INIT() macros are used only in DEFINE() macros

  + init() functions are used close to the other kthread()
    functions. It looks much better if all the functions
    use the same scheme.

  + There will be also kthread_destroy_worker() that will
    be used close to kthread_cancel_work(). It is related
    to the init() function. Again it looks better if all
    functions use the same naming scheme.

  + there are several precedents for such init() function
    names, e.g. amd_iommu_init_device(), free_area_init_node(),
    jump_label_init_type(),  regmap_init_mmio_clk(),

  + It is not an argument but it was inconsistent even before.

[arnd@arndb.de: fix linux-next merge conflict]
 Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:33 -07:00
Andy Whitcroft 5c33677c87 dm raid: fix compat_features validation
In ecbfb9f118 ("dm raid: add raid level takeover support") a new
compatible feature flag was added.  Validation for these compat_features
was added but this only passes for new raid mappings with this feature
flag.  This causes previously created raid mappings to be failed at
import.

Check compat_features for the only valid combination.

Fixes: ecbfb9f118 ("dm raid: add raid level takeover support")
Cc: stable@vger.kernel.org # v4.8
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-11 15:19:17 -04:00
Linus Torvalds 12e3d3cdd9 Merge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-block
Pull blk-mq irq/cpu mapping updates from Jens Axboe:
 "This is the block-irq topic branch for 4.9-rc. It's mostly from
  Christoph, and it allows drivers to specify their own mappings, and
  more importantly, to share the blk-mq mappings with the IRQ affinity
  mappings. It's a good step towards making this work better out of the
  box"

* 'for-4.9/block-irq' of git://git.kernel.dk/linux-block:
  blk_mq: linux/blk-mq.h does not include all the headers it depends on
  blk-mq: kill unused blk_mq_create_mq_map()
  blk-mq: get rid of the cpumask in struct blk_mq_tags
  nvme: remove the post_scan callout
  nvme: switch to use pci_alloc_irq_vectors
  blk-mq: provide a default queue mapping for PCI device
  blk-mq: allow the driver to pass in a queue mapping
  blk-mq: remove ->map_queue
  blk-mq: only allocate a single mq_map per tag_set
  blk-mq: don't redistribute hardware queues on a CPU hotplug event
2016-10-09 17:29:33 -07:00
Linus Torvalds 48915c2cbc . various fixes and cleanups for request-based DM core
. add support for delaying the requeue of requests; used by DM multipath
   when all paths have failed and 'queue_if_no_path' is enabled
 
 . DM cache improvements to speedup the loading metadata and the writing
   of the hint array
 
 . fix potential for a dm-crypt crash on device teardown
 
 . remove dm_bufio_cond_resched() and just using cond_resched()
 
 . change DM multipath to return a reservation conflict error
   immediately; rather than failing the path and retrying (potentially
   indefinitely)
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Merge tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - various fixes and cleanups for request-based DM core

 - add support for delaying the requeue of requests; used by DM
   multipath when all paths have failed and 'queue_if_no_path' is
   enabled

 - DM cache improvements to speedup the loading metadata and the writing
   of the hint array

 - fix potential for a dm-crypt crash on device teardown

 - remove dm_bufio_cond_resched() and just using cond_resched()

 - change DM multipath to return a reservation conflict error
   immediately; rather than failing the path and retrying (potentially
   indefinitely)

* tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits)
  dm mpath: always return reservation conflict without failing over
  dm bufio: remove dm_bufio_cond_resched()
  dm crypt: fix crash on exit
  dm cache metadata: switch to using the new cursor api for loading metadata
  dm array: introduce cursor api
  dm btree: introduce cursor api
  dm cache policy smq: distribute entries to random levels when switching to smq
  dm cache: speed up writing of the hint array
  dm array: add dm_array_new()
  dm mpath: delay the requeue of blk-mq requests while all paths down
  dm mpath: use dm_mq_kick_requeue_list()
  dm rq: introduce dm_mq_kick_requeue_list()
  dm rq: reduce arguments passed to map_request() and dm_requeue_original_request()
  dm rq: add DM_MAPIO_DELAY_REQUEUE to delay requeue of blk-mq requests
  dm: convert wait loops to use autoremove_wake_function()
  dm: use signal_pending_state() in dm_wait_for_completion()
  dm: rename task state function arguments
  dm: add two lockdep_assert_held() statements
  dm rq: simplify dm_old_stop_queue()
  dm mpath: check if path's request_queue is dying in activate_path()
  ...
2016-10-09 17:16:18 -07:00
Linus Torvalds 513a4befae Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the main pull request for block layer changes in 4.9.

  As mentioned at the last merge window, I've changed things up and now
  do just one branch for core block layer changes, and driver changes.
  This avoids dependencies between the two branches. Outside of this
  main pull request, there are two topical branches coming as well.

  This pull request contains:

   - A set of fixes, and a conversion to blk-mq, of nbd. From Josef.

   - Set of fixes and updates for lightnvm from Matias, Simon, and Arnd.
     Followup dependency fix from Geert.

   - General fixes from Bart, Baoyou, Guoqing, and Linus W.

   - CFQ async write starvation fix from Glauber.

   - Add supprot for delayed kick of the requeue list, from Mike.

   - Pull out the scalable bitmap code from blk-mq-tag.c and make it
     generally available under the name of sbitmap. Only blk-mq-tag uses
     it for now, but the blk-mq scheduling bits will use it as well.
     From Omar.

   - bdev thaw error progagation from Pierre.

   - Improve the blk polling statistics, and allow the user to clear
     them. From Stephen.

   - Set of minor cleanups from Christoph in block/blk-mq.

   - Set of cleanups and optimizations from me for block/blk-mq.

   - Various nvme/nvmet/nvmeof fixes from the various folks"

* 'for-4.9/block' of git://git.kernel.dk/linux-block: (54 commits)
  fs/block_dev.c: return the right error in thaw_bdev()
  nvme: Pass pointers, not dma addresses, to nvme_get/set_features()
  nvme/scsi: Remove power management support
  nvmet: Make dsm number of ranges zero based
  nvmet: Use direct IO for writes
  admin-cmd: Added smart-log command support.
  nvme-fabrics: Add host_traddr options field to host infrastructure
  nvme-fabrics: revise host transport option descriptions
  nvme-fabrics: rework nvmf_get_address() for variable options
  nbd: use BLK_MQ_F_BLOCKING
  blkcg: Annotate blkg_hint correctly
  cfq: fix starvation of asynchronous writes
  blk-mq: add flag for drivers wanting blocking ->queue_rq()
  blk-mq: remove non-blocking pass in blk_mq_map_request
  blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue()
  block: export bio_free_pages to other modules
  lightnvm: propagate device_add() error code
  lightnvm: expose device geometry through sysfs
  lightnvm: control life of nvm_dev in driver
  blk-mq: register device instead of disk
  ...
2016-10-07 14:42:05 -07:00
Linus Torvalds c23112e039 Merge tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD updates from Shaohua Li:
 "This update includes:

   - new AVX512 instruction based raid6 gen/recovery algorithm

   - a couple of md-cluster related bug fixes

   - fix a potential deadlock

   - set nonrotational bit for raid array with SSD

   - set correct max_hw_sectors for raid5/6, which hopefuly can improve
     performance a little bit

   - other minor fixes"

* tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md: set rotational bit
  raid6/test/test.c: bug fix: Specify aligned(alignment) attributes to the char arrays
  raid5: handle register_shrinker failure
  raid5: fix to detect failure of register_shrinker
  md: fix a potential deadlock
  md/bitmap: fix wrong cleanup
  raid5: allow arbitrary max_hw_sectors
  lib/raid6: Add AVX512 optimized xor_syndrome functions
  lib/raid6/test/Makefile: Add avx512 gen_syndrome and recovery functions
  lib/raid6: Add AVX512 optimized recovery functions
  lib/raid6: Add AVX512 optimized gen_syndrome functions
  md-cluster: make resync lock also could be interruptted
  md-cluster: introduce dlm_lock_sync_interruptible to fix tasks hang
  md-cluster: convert the completion to wait queue
  md-cluster: protect md_find_rdev_nr_rcu with rcu lock
  md-cluster: clean related infos of cluster
  md: changes for MD_STILL_CLOSED flag
  md-cluster: remove some unnecessary dlm_unlock_sync
  md-cluster: use FORCEUNLOCK in lockres_free
  md-cluster: call md_kick_rdev_from_array once ack failed
2016-10-07 09:45:43 -07:00
Linus Torvalds 597f03f9d1 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug updates from Thomas Gleixner:
 "Yet another batch of cpu hotplug core updates and conversions:

   - Provide core infrastructure for multi instance drivers so the
     drivers do not have to keep custom lists.

   - Convert custom lists to the new infrastructure. The block-mq custom
     list conversion comes through the block tree and makes the diffstat
     tip over to more lines removed than added.

   - Handle unbalanced hotplug enable/disable calls more gracefully.

   - Remove the obsolete CPU_STARTING/DYING notifier support.

   - Convert another batch of notifier users.

   The relayfs changes which conflicted with the conversion have been
   shipped to me by Andrew.

   The remaining lot is targeted for 4.10 so that we finally can remove
   the rest of the notifiers"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  cpufreq: Fix up conversion to hotplug state machine
  blk/mq: Reserve hotplug states for block multiqueue
  x86/apic/uv: Convert to hotplug state machine
  s390/mm/pfault: Convert to hotplug state machine
  mips/loongson/smp: Convert to hotplug state machine
  mips/octeon/smp: Convert to hotplug state machine
  fault-injection/cpu: Convert to hotplug state machine
  padata: Convert to hotplug state machine
  cpufreq: Convert to hotplug state machine
  ACPI/processor: Convert to hotplug state machine
  virtio scsi: Convert to hotplug state machine
  oprofile/timer: Convert to hotplug state machine
  block/softirq: Convert to hotplug state machine
  lib/irq_poll: Convert to hotplug state machine
  x86/microcode: Convert to hotplug state machine
  sh/SH-X3 SMP: Convert to hotplug state machine
  ia64/mca: Convert to hotplug state machine
  ARM/OMAP/wakeupgen: Convert to hotplug state machine
  ARM/shmobile: Convert to hotplug state machine
  arm64/FP/SIMD: Convert to hotplug state machine
  ...
2016-10-03 19:43:08 -07:00
Shaohua Li bb086a89a4 md: set rotational bit
if all disks in an array are non-rotational, set the array
non-rotational.

This only works for array with all disks populated at startup. Support
for disk hotadd/hotremove could be added later if necessary.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-10-03 10:20:27 -07:00
Hannes Reinecke 8ff232c1a8 dm mpath: always return reservation conflict without failing over
If dm-mpath encounters an reservation conflict it should not fail the
path (as communication with the target is not affected) but should
rather retry on another path.  However, in doing so we might be inducing
a ping-pong between paths, with no guarantee of any forward progress.
And arguably a reservation conflict is an unexpected error, so we should
be passing it upwards to allow the application to take appropriate
steps.

This change resolves a show-stopper problem seen with the pNFS SCSI
layout because it is trivial to hit reservation conflict based failover
loops without it.

Doubts were raised about the implications of this change relative to
products like IBM's SVC.  But there is little point withholding a fix
for Linux because a proprietary product may or may not have some issues
in its implementation of how it interfaces with Linux.  In the future,
if there is glaring evidence that this change is certainly problematic
we can revisit it.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com> # tweaked header
2016-09-29 10:57:07 -04:00
Peter Zijlstra 7cd326747f dm bufio: remove dm_bufio_cond_resched()
Use cond_resched() like everybody else.

Mikulas explained why dm_bufio_cond_resched() was introduced to begin
with (hopefully cond_resched can be improved accordingly) here:
https://www.redhat.com/archives/dm-devel/2016-September/msg00112.html

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com> # added last comment in header
2016-09-22 11:15:07 -04:00
Rabin Vincent f659b10087 dm crypt: fix crash on exit
As the documentation for kthread_stop() says, "if threadfn() may call
do_exit() itself, the caller must ensure task_struct can't go away".
dm-crypt does not ensure this and therefore crashes when crypt_dtr()
calls kthread_stop().  The crash is trivially reproducible by adding a
delay before the call to kthread_stop() and just opening and closing a
dm-crypt device.

 general protection fault: 0000 [#1] PREEMPT SMP
 CPU: 0 PID: 533 Comm: cryptsetup Not tainted 4.8.0-rc7+ #7
 task: ffff88003bd0df40 task.stack: ffff8800375b4000
 RIP: 0010: kthread_stop+0x52/0x300
 Call Trace:
  crypt_dtr+0x77/0x120
  dm_table_destroy+0x6f/0x120
  __dm_destroy+0x130/0x250
  dm_destroy+0x13/0x20
  dev_remove+0xe6/0x120
  ? dev_suspend+0x250/0x250
  ctl_ioctl+0x1fc/0x530
  ? __lock_acquire+0x24f/0x1b10
  dm_ctl_ioctl+0x13/0x20
  do_vfs_ioctl+0x91/0x6a0
  ? ____fput+0xe/0x10
  ? entry_SYSCALL_64_fastpath+0x5/0xbd
  ? trace_hardirqs_on_caller+0x151/0x1e0
  SyS_ioctl+0x41/0x70
  entry_SYSCALL_64_fastpath+0x1f/0xbd

This problem was introduced by bcbd94ff48 ("dm crypt: fix a possible
hang due to race condition on exit").

Looking at the description of that patch (excerpted below), it seems
like the problem it addresses can be solved by just using
set_current_state instead of __set_current_state, since we obviously
need the memory barrier.

| dm crypt: fix a possible hang due to race condition on exit
|
| A kernel thread executes __set_current_state(TASK_INTERRUPTIBLE),
| __add_wait_queue, spin_unlock_irq and then tests kthread_should_stop().
| It is possible that the processor reorders memory accesses so that
| kthread_should_stop() is executed before __set_current_state().  If
| such reordering happens, there is a possible race on thread
| termination: [...]

So this patch just reverts the aforementioned patch and changes the
__set_current_state(TASK_INTERRUPTIBLE) to set_current_state(...).  This
fixes the crash and should also fix the potential hang.

Fixes: bcbd94ff48 ("dm crypt: fix a possible hang due to race condition on exit")
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:06 -04:00
Joe Thornber f177940a80 dm cache metadata: switch to using the new cursor api for loading metadata
This change offers a pretty significant performance improvement.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:05 -04:00
Joe Thornber fdd1315aa5 dm array: introduce cursor api
More efficient way to iterate an array due to prefetching (makes use of
the new dm_btree_cursor_* api).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:04 -04:00
Joe Thornber 7d111c81fa dm btree: introduce cursor api
This uses prefetching to speed up iteration through a btree.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:04 -04:00
Joe Thornber 9d1b404cbc dm cache policy smq: distribute entries to random levels when switching to smq
For smq the 32 bit 'hint' stores the multiqueue level that the entry
should be stored in.  If a different policy has been used previously,
and then switched to smq, the hints will be invalid.  In which case we
used to put all entries in the bottom level of the multiqueue, and then
redistribute.  Redistribution is faster if we put entries with invalid
hints in random levels initially.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:03 -04:00
Joe Thornber 4e781b498e dm cache: speed up writing of the hint array
It's far quicker to always delete the hint array and recreate with
dm_array_new() because we avoid the copying caused by mutation.

Also simplifies the policy interface, replacing the walk_hints() with
the simpler get_hint().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:15:02 -04:00
Joe Thornber dd6a77d998 dm array: add dm_array_new()
dm_array_new() creates a new, populated array more efficiently than
starting with an empty one and resizing.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-22 11:12:23 -04:00
Guoqing Jiang 491221f88d block: export bio_free_pages to other modules
bio_free_pages is introduced in commit 1dfa0f68c0
("block: add a helper to free bio bounce buffer pages"),
we can reuse the func in other modules after it was
imported.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-22 07:48:03 -06:00
Shaohua Li 30c8946566 raid5: handle register_shrinker failure
register_shrinker() now can fail. When it happens, shrinker.nr_deferred is
null. We use it to determine if unregister_shrinker is required.

Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00
Chao Yu 6a0f53ff35 raid5: fix to detect failure of register_shrinker
register_shrinker can fail after commit 1d3d4437ea ("vmscan: per-node
deferred work"), we should detect the failure of it, otherwise we may
fail to register shrinker after raid5 configuration was setup successfully.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00
Shaohua Li 90bcf13381 md: fix a potential deadlock
lockdep reports a potential deadlock. Fix this by droping the mutex
before md_import_device

[ 1137.126601] ======================================================
[ 1137.127013] [ INFO: possible circular locking dependency detected ]
[ 1137.127013] 4.8.0-rc4+ #538 Not tainted
[ 1137.127013] -------------------------------------------------------
[ 1137.127013] mdadm/16675 is trying to acquire lock:
[ 1137.127013]  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81243cf3>] __blkdev_get+0x63/0x450
[ 1137.127013]
but task is already holding lock:
[ 1137.127013]  (detected_devices_mutex){+.+.+.}, at: [<ffffffff81a5138c>] md_ioctl+0x2ac/0x1f50
[ 1137.127013]
which lock already depends on the new lock.

[ 1137.127013]
the existing dependency chain (in reverse order) is:
[ 1137.127013]
-> #1 (detected_devices_mutex){+.+.+.}:
[ 1137.127013]        [<ffffffff810b6f19>] lock_acquire+0xb9/0x220
[ 1137.127013]        [<ffffffff81c51647>] mutex_lock_nested+0x67/0x3d0
[ 1137.127013]        [<ffffffff81a4eeaf>] md_autodetect_dev+0x3f/0x90
[ 1137.127013]        [<ffffffff81595be8>] rescan_partitions+0x1a8/0x2c0
[ 1137.127013]        [<ffffffff81590081>] __blkdev_reread_part+0x71/0xb0
[ 1137.127013]        [<ffffffff815900e5>] blkdev_reread_part+0x25/0x40
[ 1137.127013]        [<ffffffff81590c4b>] blkdev_ioctl+0x51b/0xa30
[ 1137.127013]        [<ffffffff81242bf1>] block_ioctl+0x41/0x50
[ 1137.127013]        [<ffffffff81214c96>] do_vfs_ioctl+0x96/0x6e0
[ 1137.127013]        [<ffffffff81215321>] SyS_ioctl+0x41/0x70
[ 1137.127013]        [<ffffffff81c56825>] entry_SYSCALL_64_fastpath+0x18/0xa8
[ 1137.127013]
-> #0 (&bdev->bd_mutex){+.+.+.}:
[ 1137.127013]        [<ffffffff810b6af2>] __lock_acquire+0x1662/0x1690
[ 1137.127013]        [<ffffffff810b6f19>] lock_acquire+0xb9/0x220
[ 1137.127013]        [<ffffffff81c51647>] mutex_lock_nested+0x67/0x3d0
[ 1137.127013]        [<ffffffff81243cf3>] __blkdev_get+0x63/0x450
[ 1137.127013]        [<ffffffff81244307>] blkdev_get+0x227/0x350
[ 1137.127013]        [<ffffffff812444f6>] blkdev_get_by_dev+0x36/0x50
[ 1137.127013]        [<ffffffff81a46d65>] lock_rdev+0x35/0x80
[ 1137.127013]        [<ffffffff81a49bb4>] md_import_device+0xb4/0x1b0
[ 1137.127013]        [<ffffffff81a513d6>] md_ioctl+0x2f6/0x1f50
[ 1137.127013]        [<ffffffff815909b3>] blkdev_ioctl+0x283/0xa30
[ 1137.127013]        [<ffffffff81242bf1>] block_ioctl+0x41/0x50
[ 1137.127013]        [<ffffffff81214c96>] do_vfs_ioctl+0x96/0x6e0
[ 1137.127013]        [<ffffffff81215321>] SyS_ioctl+0x41/0x70
[ 1137.127013]        [<ffffffff81c56825>] entry_SYSCALL_64_fastpath+0x18/0xa8
[ 1137.127013]
other info that might help us debug this:

[ 1137.127013]  Possible unsafe locking scenario:

[ 1137.127013]        CPU0                    CPU1
[ 1137.127013]        ----                    ----
[ 1137.127013]   lock(detected_devices_mutex);
[ 1137.127013]                                lock(&bdev->bd_mutex);
[ 1137.127013]                                lock(detected_devices_mutex);
[ 1137.127013]   lock(&bdev->bd_mutex);
[ 1137.127013]
 *** DEADLOCK ***

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00
Shaohua Li f71f1cf97c md/bitmap: fix wrong cleanup
if bitmap_create fails, the bitmap is already cleaned up and the returned value
is an error number. We can't do the cleanup again.

Reported-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00
Shaohua Li 1dffddddd8 raid5: allow arbitrary max_hw_sectors
raid5 will split bio to proper size internally, there is no point to use
underlayer disk's max_hw_sectors. In my qemu system, without the change,
the raid5 only receives 128k size bio, which reduces the chance of bio
merge sending to underlayer disks.

Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00
Guoqing Jiang d6385db941 md-cluster: make resync lock also could be interruptted
When one node is perform resync or recovery, other nodes
can't get resync lock and could block for a while before
it holds the lock, so we can't stop array immediately for
this scenario.

To make array could be stop quickly, we check MD_CLOSING
in dlm_lock_sync_interruptible to make us can interrupt
the lock request.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00
Guoqing Jiang 7bcda7149d md-cluster: introduce dlm_lock_sync_interruptible to fix tasks hang
When some node leaves cluster, then it's bitmap need to be
synced by another node, so "md*_recover" thread is triggered
for the purpose. However, with below steps. we can find tasks
hang happened either in B or C.

1. Node A create a resyncing cluster raid1, assemble it in
   other two nodes (B and C).
2. stop array in B and C.
3. stop array in A.

linux44:~ # ps aux|grep md|grep D
root	5938	0.0  0.1  19852  1964 pts/0    D+   14:52   0:00 mdadm -S md0
root	5939	0.0  0.0      0     0 ?        D    14:52   0:00 [md0_recover]

linux44:~ # cat /proc/5939/stack
[<ffffffffa04cf321>] dlm_lock_sync+0x71/0x90 [md_cluster]
[<ffffffffa04d0705>] recover_bitmaps+0x125/0x220 [md_cluster]
[<ffffffffa052105d>] md_thread+0x16d/0x180 [md_mod]
[<ffffffff8107ad94>] kthread+0xb4/0xc0
[<ffffffff8152a518>] ret_from_fork+0x58/0x90

linux44:~ # cat /proc/5938/stack
[<ffffffff8107afde>] kthread_stop+0x6e/0x120
[<ffffffffa0519da0>] md_unregister_thread+0x40/0x80 [md_mod]
[<ffffffffa04cfd20>] leave+0x70/0x120 [md_cluster]
[<ffffffffa0525e24>] md_cluster_stop+0x14/0x30 [md_mod]
[<ffffffffa05269ab>] bitmap_free+0x14b/0x150 [md_mod]
[<ffffffffa0523f3b>] do_md_stop+0x35b/0x5a0 [md_mod]
[<ffffffffa0524e83>] md_ioctl+0x873/0x1590 [md_mod]
[<ffffffff81288464>] blkdev_ioctl+0x214/0x7d0
[<ffffffff811dd3dd>] block_ioctl+0x3d/0x40
[<ffffffff811b92d4>] do_vfs_ioctl+0x2d4/0x4b0
[<ffffffff811b9538>] SyS_ioctl+0x88/0xa0
[<ffffffff8152a5c9>] system_call_fastpath+0x16/0x1b

The problem is caused by recover_bitmaps can't reliably abort
when the thread is unregistered. So dlm_lock_sync_interruptible
is introduced to detect the thread's situation to fix the problem.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21 09:09:44 -07:00