[ Upstream commit d63e2fc804 ]
During raid5 replacement, the stripes can be marked with R5_NeedReplace
flag. Data can be read from being-replaced devices and written to
replacing spares without reading all other devices. (It's 'replace'
mode. s.replacing = 1) If a being-replaced device is dropped, the
replacement progress will be interrupted and resumed with pure recovery
mode. However, existing stripes before being interrupted cannot read
from the dropped device anymore. It prints lots of WARN_ON messages.
And it results in data corruption because existing stripes write
problematic data into its replacement device and update the progress.
\# Erase disks (1MB + 2GB)
dd if=/dev/zero of=/dev/sda bs=1MB count=2049
dd if=/dev/zero of=/dev/sdb bs=1MB count=2049
dd if=/dev/zero of=/dev/sdc bs=1MB count=2049
dd if=/dev/zero of=/dev/sdd bs=1MB count=2049
mdadm -C /dev/md0 -amd -R -l5 -n3 -x0 /dev/sd[abc] -z 2097152
\# Ensure array stores non-zero data
dd if=/root/data_4GB.iso of=/dev/md0 bs=1MB
\# Start replacement
mdadm /dev/md0 -a /dev/sdd
mdadm /dev/md0 --replace /dev/sda
Then, Hot-plug out /dev/sda during recovery, and wait for recovery done.
echo check > /sys/block/md0/md/sync_action
cat /sys/block/md0/md/mismatch_cnt # it will be greater than 0.
Soon after you hot-plug out /dev/sda, you will see many WARN_ON
messages. The replacement recovery will be interrupted shortly. After
the recovery finishes, it will result in data corruption.
Actually, it's just an unhandled case of replacement. In commit
<f94c0b6658c7> (md/raid5: fix interaction of 'replace' and 'recovery'.),
if a NeedReplace device is not UPTODATE then that is an error, the
commit just simply print WARN_ON but also mark these corrupted stripes
with R5_WantReplace. (it means it's ready for writes.)
To fix this case, we can leverage 'sync and replace' mode mentioned in
commit <9a3e1101b827> (md/raid5: detect and handle replacements during
recovery.). We can add logics to detect and use 'sync and replace' mode
for these stripes.
Reported-by: Alex Chen <alexchen@synology.com>
Reviewed-by: Alex Wu <alexwu@synology.com>
Reviewed-by: Chung-Chiang Cheng <cccheng@synology.com>
Signed-off-by: BingJing Chang <bingjingc@synology.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8876391e44 ]
There is a potential deadlock if mount/umount happens when
raid5_finish_reshape() tries to grow the size of emulated disk.
How the deadlock happens?
1) The raid5 resync thread finished reshape (expanding array).
2) The mount or umount thread holds VFS sb->s_umount lock and tries to
write through critical data into raid5 emulated block device. So it
waits for raid5 kernel thread handling stripes in order to finish it
I/Os.
3) In the routine of raid5 kernel thread, md_check_recovery() will be
called first in order to reap the raid5 resync thread. That is,
raid5_finish_reshape() will be called. In this function, it will try
to update conf and call VFS revalidate_disk() to grow the raid5
emulated block device. It will try to acquire VFS sb->s_umount lock.
The raid5 kernel thread cannot continue, so no one can handle mount/
umount I/Os (stripes). Once the write-through I/Os cannot be finished,
mount/umount will not release sb->s_umount lock. The deadlock happens.
The raid5 kernel thread is an emulated block device. It is responible to
handle I/Os (stripes) from upper layers. The emulated block device
should not request any I/Os on itself. That is, it should not call VFS
layer functions. (If it did, it will try to acquire VFS locks to
guarantee the I/Os sequence.) So we have the resync thread to send
resync I/O requests and to wait for the results.
For solving this potential deadlock, we can put the size growth of the
emulated block device as the final step of reshape thread.
2017/12/29:
Thanks to Guoqing Jiang <gqjiang@suse.com>,
we confirmed that there is the same deadlock issue in raid10. It's
reproducible and can be fixed by this patch. For raid10.c, we can remove
the similar code to prevent deadlock as well since they has been called
before.
Reported-by: Alex Wu <alexwu@synology.com>
Reviewed-by: Alex Wu <alexwu@synology.com>
Reviewed-by: Chung-Chiang Cheng <cccheng@synology.com>
Signed-off-by: BingJing Chang <bingjingc@synology.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 53b8d89ddb ]
gcc warns about a possible overflow of the kmem_cache string, when adding
four characters to a string of the same length:
drivers/md/raid5.c: In function 'setup_conf':
drivers/md/raid5.c:2207:34: error: '-alt' directive writing 4 bytes into a region of size between 1 and 32 [-Werror=format-overflow=]
sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
^~~~
drivers/md/raid5.c:2207:2: note: 'sprintf' output between 5 and 36 bytes into a destination of size 32
sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If I'm counting correctly, we need 11 characters for the fixed part
of the string and 18 characters for a 64-bit pointer (when no gendisk
is used), so that leaves three characters for conf->level, which should
always be sufficient.
This makes the code use snprintf() with the correct length, to
make the code more robust against changes, and to get the compiler
to shut up.
In commit f4be6b43f1 ("md/raid5: ensure we create a unique name for
kmem_cache when mddev has no gendisk") from 2010, Neil said that
the pointer could be removed "shortly" once devices without gendisk
are disallowed. I have no idea if that happened, but if it did, that
should probably be changed as well.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3d05f3aed5 ]
On mainline, there is no functional difference, just less code, and
symmetric lock/unlock paths.
On PREEMPT_RT builds, this fixes the following warning, seen by
Alexander GQ Gerasiov, due to the sleeping nature of spinlocks.
BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:993
in_atomic(): 0, irqs_disabled(): 1, pid: 58, name: kworker/u12:1
CPU: 5 PID: 58 Comm: kworker/u12:1 Tainted: G W 4.9.20-rt16-stand6-686 #1
Hardware name: Supermicro SYS-5027R-WRF/X9SRW-F, BIOS 3.2a 10/28/2015
Workqueue: writeback wb_workfn (flush-253:0)
Call Trace:
dump_stack+0x47/0x68
? migrate_enable+0x4a/0xf0
___might_sleep+0x101/0x180
rt_spin_lock+0x17/0x40
add_stripe_bio+0x4e3/0x6c0 [raid456]
? preempt_count_add+0x42/0xb0
raid5_make_request+0x737/0xdd0 [raid456]
Reported-by: Alexander GQ Gerasiov <gq@redlab-i.ru>
Tested-by: Alexander GQ Gerasiov <gq@redlab-i.ru>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7471fb77ce ]
When recoverying a single missing/failed device in a RAID6,
those stripes where the Q block is on the missing device are
handled a bit differently. In these cases it is easy to
check that the P block is correct, so we do. This results
in the P block be destroy. Consequently the P block needs
to be read a second time in order to compute Q. This causes
lots of seeks and hurts performance.
It shouldn't be necessary to re-read P as it can be computed
from the DATA. But we only compute blocks on missing
devices, since c337869d95 ("md: do not compute parity
unless it is on a failed drive").
So relax the change made in that commit to allow computing
of the P block in a RAID6 which it is the only missing that
block.
This makes RAID6 recovery run much faster as the disk just
"before" the recovering device is no longer seeking
back-and-forth.
Reported-by-tested-by: Brad Campbell <lists2009@fnarfbargle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 235b6003fb ]
When reshaping a fully degraded raid5/raid6 to a larger
nubmer of devices, the new device(s) are not in-sync
and so that can make the newly grown stripe appear to be
"failed".
To avoid this, we set the R5_Expanded flag to say "Even though
this device is not fully in-sync, this block is safe so
don't treat the device as failed for this stripe".
This flag is set for data devices, not not for parity devices.
Consequently, if you have a RAID6 with two devices that are partly
recovered and a spare, and start a reshape to include the spare,
then when the reshape gets past the point where the recovery was
up to, it will think the stripes are failed and will get into
an infinite loop, failing to make progress.
So when contructing parity on an EXPAND_READY stripe,
set R5_Expanded.
Reported-by: Curt <lightspd@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 184a09eb9a upstream.
In release_stripe_plug(), if a stripe_head has its STRIPE_ON_UNPLUG_LIST
set, it indicates that this stripe_head is already in the raid5_plug_cb
list and release_stripe() would be called instead to drop a reference
count. Otherwise, the STRIPE_ON_UNPLUG_LIST bit would be set for this
stripe_head and it will get queued into the raid5_plug_cb list.
Since break_stripe_batch_list() did not preserve STRIPE_ON_UNPLUG_LIST,
A stripe could be re-added to plug list while it is still on that list
in the following situation. If stripe_head A is added to another
stripe_head B's batch list, in this case A will have its
batch_head != NULL and be added into the plug list. After that,
stripe_head B gets handled and called break_stripe_batch_list() to
reset all the batched stripe_head(including A which is still on
the plug list)'s state and reset their batch_head to NULL.
Before the plug list gets processed, if there is another write request
comes in and get stripe_head A, A will have its batch_head == NULL
(cleared by calling break_stripe_batch_list() on B) and be added to
plug list once again.
Signed-off-by: Dennis Yang <dennisyang@qnap.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3664847d95 upstream.
We have a race condition in below scenario, say have 3 continuous stripes, sh1,
sh2 and sh3, sh1 is the stripe_head of sh2 and sh3:
CPU1 CPU2 CPU3
handle_stripe(sh3)
stripe_add_to_batch_list(sh3)
-> lock(sh2, sh3)
-> lock batch_lock(sh1)
-> add sh3 to batch_list of sh1
-> unlock batch_lock(sh1)
clear_batch_ready(sh1)
-> lock(sh1) and batch_lock(sh1)
-> clear STRIPE_BATCH_READY for all stripes in batch_list
-> unlock(sh1) and batch_lock(sh1)
->clear_batch_ready(sh3)
-->test_and_clear_bit(STRIPE_BATCH_READY, sh3)
--->return 0 as sh->batch == NULL
-> sh3->batch_head = sh1
-> unlock (sh2, sh3)
In CPU1, handle_stripe will continue handle sh3 even it's in batch stripe list
of sh1. By moving sh3->batch_head assignment in to batch_lock, we make it
impossible to clear STRIPE_BATCH_READY before batch_head is set.
Thanks Stephane for helping debug this tricky issue.
Reported-and-tested-by: Stephane Thiell <sthiell@stanford.edu>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9c72a18e46 upstream.
In raid5, there are scenarios where some ios are deferred to a later
time, and some IO need a flush to complete. To make sure we make
progress with these IOs, we need to call the following functions:
flush_deferred_bios(conf);
r5l_flush_stripe_to_raid(conf->log);
Both of these functions are called in raid5d(), but missing in
raid5_do_work(). As a result, these functions are not called
when multi-threading (group_thread_cnt > 0) is enabled. This patch
adds calls to these function to raid5_do_work().
Note for stable branches:
r5l_flush_stripe_to_raid(conf->log) is need for 4.4+
flush_deferred_bios(conf) is only needed for 4.11+
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7e96d55963 upstream.
Since thread_group worker and raid5d kthread are not in sync, if
worker writes stripe before raid5d then requests will be waiting
for issue_pendig.
Issue observed when building raid5 with ext4, in some build runs
jbd2 would get hung and requests were waiting in the HW engine
waiting to be issued.
Fix this by adding a call to async_tx_issue_pending_all in the
raid5_do_work.
Signed-off-by: Ofer Heifetz <oferh@marvell.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5d27718f3 upstream.
The raid5 md device is created by the disks which we don't use the total size. For example,
the size of the device is 5G and it just uses 3G of the devices to create one raid5 device.
Then change the chunksize and wait reshape to finish. After reshape finishing stop the raid
and assemble it again. It fails.
mdadm -CR /dev/md0 -l5 -n3 /dev/loop[0-2] --size=3G --chunk=32 --assume-clean
mdadm /dev/md0 --grow --chunk=64
wait reshape to finish
mdadm -S /dev/md0
mdadm -As
The error messages:
[197519.814302] md: loop1 does not have a valid v1.2 superblock, not importing!
[197519.821686] md: md_import_device returned -22
After reshape the data offset is changed. It selects backwards direction in this condition.
In function super_1_load it compares the available space of the underlying device with
sb->data_size. The new data offset gets bigger after reshape. So super_1_load returns -EINVAL.
rdev->sectors is updated in md_finish_reshape. Then sb->data_size is set in super_1_sync based
on rdev->sectors. So add md_finish_reshape in end_reshape.
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f9c79bc05a upstream.
The function flush_signals clears all pending signals for the process. It
may be used by kernel threads when we need to prepare a kernel thread for
responding to signals. However using this function for an userspaces
processes is incorrect - clearing signals without the program expecting it
can cause misbehavior.
The raid1 and raid5 code uses flush_signals in its request routine because
it wants to prepare for an interruptible wait. This patch drops
flush_signals and uses sigprocmask instead to block all signals (including
SIGKILL) around the schedule() call. The signals are not lost, but the
schedule() call won't respond to them.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e8d7c33232 upstream.
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>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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
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
...
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>
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>
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>
commit 5f9d1fde7d54a5(raid5: fix memory leak of bio integrity data)
moves bio_reset to bio_endio. But it introduces a small race condition.
It does bio_reset after raid5_release_stripe, which could make the
stripe reusable and hence reuse the bio just before bio_reset. Moving
bio_reset before raid5_release_stripe is called should fix the race.
Reported-and-tested-by: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Signed-off-by: Shaohua Li <shli@fb.com>
If there aren't enough stripes, reshape will hang. We have a check for
this in new reshape, but miss it for reshape resume, hence we could see
hang in reshape resume. This patch forces enough stripes existed if
reshape resumes.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Pull MD fixes from Shaohua Li:
"This includes several bug fixes:
- Alexey Obitotskiy fixed a hang for faulty raid5 array with external
management
- Song Liu fixed two raid5 journal related bugs
- Tomasz Majchrzak fixed a bad block recording issue and an
accounting issue for raid10
- ZhengYuan Liu fixed an accounting issue for raid5
- I fixed a potential race condition and memory leak with DIF/DIX
enabled
- other trival fixes"
* tag 'md/4.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
raid5: avoid unnecessary bio data set
raid5: fix memory leak of bio integrity data
raid10: record correct address of bad block
md-cluster: fix error return code in join()
r5cache: set MD_JOURNAL_CLEAN correctly
md: don't print the same repeated messages about delayed sync operation
md: remove obsolete ret in md_start_sync
md: do not count journal as spare in GET_ARRAY_INFO
md: Prevent IO hold during accessing to faulty raid5 array
MD: hold mddev lock to change bitmap location
raid5: fix incorrectly counter of conf->empty_inactive_list_nr
raid10: increment write counter after bio is split
bio_reset doesn't change bi_io_vec and bi_max_vecs, so we don't need to
set them every time. bi_private will be set before the bio is
dispatched.
Signed-off-by: Shaohua Li <shli@fb.com>
Yi reported a memory leak of raid5 with DIF/DIX enabled disks. raid5
doesn't alloc/free bio, instead it reuses bios. There are two issues in
current code:
1. the code calls bio_init (from
init_stripe->raid5_build_block->bio_init) then bio_reset (ops_run_io).
The bio is reused, so likely there is integrity data attached. bio_init
will clear a pointer to integrity data and makes bio_reset can't release
the data
2. bio_reset is called before dispatching bio. After bio is finished,
it's possible we don't free bio's integrity data (eg, we don't call
bio_reset again)
Both issues will cause memory leak. The patch moves bio_init to stripe
creation and bio_reset to bio end io. This will fix the two issues.
Reported-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Currently, the code sets MD_JOURNAL_CLEAN when the array has
MD_FEATURE_JOURNAL and the recovery_cp is MaxSector. The array
will be MD_JOURNAL_CLEAN even if the journal device is missing.
With this patch, the MD_JOURNAL_CLEAN is only set when the journal
device presents.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Since commit 63a4cc2486, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.
No intended functional changes in this commit.
Signed-off-by: Jens Axboe <axboe@fb.com>
After array enters in faulty state (e.g. number of failed drives
becomes more then accepted for raid5 level) it sets error flags
(one of this flags is MD_CHANGE_PENDING). For internal metadata
arrays MD_CHANGE_PENDING cleared into md_update_sb, but not for
external metadata arrays. MD_CHANGE_PENDING flag set prevents to
finish all new or non-finished IOs to array and hold them in
pending state. In some cases this can leads to deadlock situation.
For example, we have faulty array (2 of 4 drives failed) and
udev handle array state changes and blkid started (or other
userspace application that used array to read/write) but unable
to finish reads due to IO hold. At the same time we unable to get
exclusive access to array (to stop array in our case) because
another external application still use this array.
Fix makes possible to return IO with errors immediately.
So external application can finish working with array and
give exclusive access to other applications to perform
required management actions with array.
Signed-off-by: Alexey Obitotskiy <aleksey.obitotskiy@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The counter conf->empty_inactive_list_nr is only used for determine if the
raid5 is congested which is deal with in function raid5_congested().
It was increased in get_free_stripe() when conf->inactive_list got to be
empty and decreased in release_inactive_stripe_list() when splice
temp_inactive_list to conf->inactive_list. However, this may have a
problem when raid5_get_active_stripe or stripe_add_to_batch_list was called,
because these two functions may call list_del_init(&sh->lru) to delete sh from
"conf->inactive_list + hash" which may cause "conf->inactive_list + hash" to
be empty when atomic_inc_not_zero(&sh->count) got false. So a check should be
done at these two point and increase empty_inactive_list_nr accordingly.
Otherwise the counter may get to be negative number which would influence
async readahead from VFS.
Signed-off-by: ZhengYuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces. For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense. Any check for READA is replaced with an
explicit check for REQ_RAHEAD. Also remove the READA alias for
REQ_RAHEAD.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Every time a device is removed with ->hot_remove_disk() a synchronize_rcu() call is made
which can delay several milliseconds in some case.
If lots of devices fail at once - as could happen with a large RAID10 where one set
of devices are removed all at once - these delays can add up to be very inconcenient.
As failure is not reversible we can check for that first, setting a
separate flag if it is found, and then all synchronize_rcu() once for
all the flagged devices. Then ->hot_remove_disk() function can skip the
synchronize_rcu() step if the flag is set.
fix build error(Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
It is important that we never increment rdev->nr_pending on a Faulty
device as ->hot_remove_disk() assumes that once the Faulty flag is visible
no code will take a new reference.
Some places take a new reference after only check In_sync. This should
be safe as the two are changed together. However to make the code more
obviously safe, add checks for 'Faulty' as well.
Note: the actual rule is:
Never increment nr_pending if Faulty is set and Blocked is clear,
never clear Faulty, and never set Blocked without holding a reference
through nr_pending.
fix build error (Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Being in the middle of resync is no longer protection against failed
rdevs disappearing. So add rcu protection.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The rdev could be freed while handle_failed_sync is running, so
rcu protection is needed.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We don't need bi_rw to be so large on 64 bit archs, so
reduce it to unsigned int.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Separate the op from the rq_flag_bits and have md
set/get the bio using bio_set_op_attrs/bio_op.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In current handle_stripe_dirtying, the code prefers rmw with
PARITY_ENABLE_RMW; while prefers rcw with PARITY_PREFER_RMW.
This patch reverses this behavior.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Some code waits for a metadata update by:
1. flagging that it is needed (MD_CHANGE_DEVS or MD_CHANGE_CLEAN)
2. setting MD_CHANGE_PENDING and waking the management thread
3. waiting for MD_CHANGE_PENDING to be cleared
If the first two are done without locking, the code in md_update_sb()
which checks if it needs to repeat might test if an update is needed
before step 1, then clear MD_CHANGE_PENDING after step 2, resulting
in the wait returning early.
So make sure all places that set MD_CHANGE_PENDING are atomicial, and
bit_clear_unless (suggested by Neil) is introduced for the purpose.
Cc: Martin Kepplinger <martink@posteo.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: <linux-kernel@vger.kernel.org>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
In case md runs underneath the dm-raid target, the mddev does not have
a request queue or gendisk, thus avoid accesses.
This patch adds a missing conditional to the raid5 personality.
Signed-of-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
If device has R5_LOCKED set, it's legit device has R5_SkipCopy set and page !=
orig_page. After R5_LOCKED is clear, handle_stripe_clean_event will clear the
SkipCopy flag and set page to orig_page. So the warning is unnecessary.
Reported-by: Joey Liao <joeyliao@qnap.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The raid456_cpu_notify() hotplug callback lacks handling of the
CPU_UP_CANCELED case. That means if CPU_UP_PREPARE fails, the scratch
buffer is leaked.
Add handling for CPU_UP_CANCELED[_FROZEN] hotplug notifier transitions
to free the scratch buffer.
CC: Shaohua Li <shli@kernel.org>
CC: linux-raid@vger.kernel.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Neil recently fixed an obscure race in break_stripe_batch_list. Debug would be
quite convenient if we know the stripe state. This is what this patch does.
Signed-off-by: Shaohua Li <shli@fb.com>
break_stripe_batch_list breaks up a batch and copies some flags from
the batch head to the members, preserving others.
It doesn't preserve or copy STRIPE_PREREAD_ACTIVE. This is not
normally a problem as STRIPE_PREREAD_ACTIVE is cleared when a
stripe_head is added to a batch, and is not set on stripe_heads
already in a batch.
However there is no locking to ensure one thread doesn't set the flag
after it has just been cleared in another. This does occasionally happen.
md/raid5 maintains a count of the number of stripe_heads with
STRIPE_PREREAD_ACTIVE set: conf->preread_active_stripes. When
break_stripe_batch_list clears STRIPE_PREREAD_ACTIVE inadvertently
this could becomes incorrect and will never again return to zero.
md/raid5 delays the handling of some stripe_heads until
preread_active_stripes becomes zero. So when the above mention race
happens, those stripe_heads become blocked and never progress,
resulting is write to the array handing.
So: change break_stripe_batch_list to preserve STRIPE_PREREAD_ACTIVE
in the members of a batch.
URL: https://bugzilla.kernel.org/show_bug.cgi?id=108741
URL: https://bugzilla.redhat.com/show_bug.cgi?id=1258153
URL: http://thread.gmane.org/5649C0E9.2030204@zoner.cz
Reported-by: Martin Svec <martin.svec@zoner.cz> (and others)
Tested-by: Tom Weber <linux@junkyard.4t2.com>
Fixes: 1b956f7a8f ("md/raid5: be more selective about distributing flags across batch.")
Cc: stable@vger.kernel.org (v4.1 and later)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Revert commit
e9e4c377e2f563(md/raid5: per hash value and exclusive wait_for_stripe)
The problem is raid5_get_active_stripe waits on
conf->wait_for_stripe[hash]. Assume hash is 0. My test release stripes
in this order:
- release all stripes with hash 0
- raid5_get_active_stripe still sleeps since active_stripes >
max_nr_stripes * 3 / 4
- release all stripes with hash other than 0. active_stripes becomes 0
- raid5_get_active_stripe still sleeps, since nobody wakes up
wait_for_stripe[0]
The system live locks. The problem is active_stripes isn't a per-hash
count. Revert the patch makes the live lock go away.
Cc: stable@vger.kernel.org (v4.2+)
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Shaohua Li <shli@fb.com>
check_reshape() is called from raid5d thread. raid5d thread shouldn't
call mddev_suspend(), because mddev_suspend() waits for all IO finish
but IO is handled in raid5d thread, we could easily deadlock here.
This issue is introduced by
738a273 ("md/raid5: fix allocation of 'scribble' array.")
Cc: stable@vger.kernel.org (v4.1+)
Reported-and-tested-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
'max_discard_sectors' is in sectors, while 'stripe' is in bytes.
This fixes the problem where DISCARD would get disabled on some larger
RAID5 configurations (6 or more drives in my testing), while it worked
as expected with smaller configurations.
Fixes: 620125f2bf ("MD: raid5 trim support")
Cc: stable@vger.kernel.org v3.7+
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
