Currently there is an inconsistency for failing the member drives
for arrays with different RAID levels. For RAID456 - there is a possibility
to fail all of the devices. However - for other RAID levels - kernel blocks
removing the member drive, if the operation results in array's FAIL state
(EBUSY is returned). For example - removing last drive from RAID1 is not
possible.
This kind of blocker was never implemented for raid456 and we cannot see
the reason why.
We had tested following patch and did not observe any regression, so do you
have any comments/reasons for current approach, or we can send the proper
patch for this?
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
We don't support reshape yet if an array supports log device. Previously we
determine the fact by checking ->log. However, ->log could be NULL after a log
device is removed, but the array is still marked to support log device. Don't
allow reshape in this case too. User can disable log device support by setting
'consistency_policy' to 'resync' then do reshape.
Reported-by: Xiao Ni <xni@redhat.com>
Tested-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Pull input updates from Dmitry Torokhov:
- a new driver for Rohm BU21029 touch controller
- new bitmap APIs: bitmap_alloc, bitmap_zalloc and bitmap_free
- updates to Atmel, eeti. pxrc and iforce drivers
- assorted driver cleanups and fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (57 commits)
MAINTAINERS: Add PhoenixRC Flight Controller Adapter
Input: do not use WARN() in input_alloc_absinfo()
Input: mark expected switch fall-throughs
Input: raydium_i2c_ts - use true and false for boolean values
Input: evdev - switch to bitmap API
Input: gpio-keys - switch to bitmap_zalloc()
Input: elan_i2c_smbus - cast sizeof to int for comparison
bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()
md: Avoid namespace collision with bitmap API
dm: Avoid namespace collision with bitmap API
Input: pm8941-pwrkey - add resin entry
Input: pm8941-pwrkey - abstract register offsets and event code
Input: iforce - reorganize joystick configuration lists
Input: atmel_mxt_ts - move completion to after config crc is updated
Input: atmel_mxt_ts - don't report zero pressure from T9
Input: atmel_mxt_ts - zero terminate config firmware file
Input: atmel_mxt_ts - refactor config update code to add context struct
Input: atmel_mxt_ts - config CRC may start at T71
Input: atmel_mxt_ts - remove unnecessary debug on ENOMEM
Input: atmel_mxt_ts - remove duplicate setup of ABS_MT_PRESSURE
...
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>
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.
On the other hand MD bitmap API is special case.
Adding 'md' prefix to it to avoid name space collision.
No functional changes intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Shaohua Li <shli@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
There is no need to invoke release_inactive_stripe_list() with interrupts
disabled. All call sites, except raid5_release_stripe(), unlock
->device_lock and enable interrupts before invoking the function.
Make it consistent.
Cc: Shaohua Li <shli@kernel.org>
Cc: linux-raid@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Shaohua Li <shli@fb.com>
The irqsave variant of atomic_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock. With this variant the call of
local_irq_save is no longer required.
Cc: Shaohua Li <shli@kernel.org>
Cc: linux-raid@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Pull MD updates from Shaohua Li:
"A few fixes of MD for this merge window. Mostly bug fixes:
- raid5 stripe batch fix from Amy
- Read error handling for raid1 FailFast device from Gioh
- raid10 recovery NULL pointer dereference fix from Guoqing
- Support write hint for raid5 stripe cache from Mariusz
- Fixes for device hot add/remove from Neil and Yufen
- Improve flush bio scalability from Xiao"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
MD: fix lock contention for flush bios
md/raid5: Assigning NULL to sh->batch_head before testing bit R5_Overlap of a stripe
md/raid1: add error handling of read error from FailFast device
md: fix NULL dereference of mddev->pers in remove_and_add_spares()
raid5: copy write hint from origin bio to stripe
md: fix two problems with setting the "re-add" device state.
raid10: check bio in r10buf_pool_free to void NULL pointer dereference
md: fix an error code format and remove unsed bio_sector
In add_stripe_bio(), if the stripe_head is in batch list, the incoming
bio is regarded as overlapping, and the bit R5_Overlap on this stripe_head
is set. break_stripe_batch_list() checks bit R5_Overlap on each stripe_head
first then assigns NULL to sh->batch_head.
If break_stripe_batch_list() checks bit R5_Overlap on stripe_head A
after add_stripe_bio() finds stripe_head A is in batch list and before
add_stripe_bio() sets bit R5_Overlapt of stripe_head A,
break_stripe_batch_list() would not know there's a process in
wait_for_overlap and needs to call wake_up(). There's a huge chance a
process never returns from schedule() if add_stripe_bio() is called
from raid5_make_request().
In break_stripe_batch_list(), assigning NULL to sh->batch_head should
be done before it checks bit R5_Overlap of a stripe_head.
Signed-off-by: Amy Chiang <amychiang@qnap.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Store write hint from original bio in stripe head so it can be assigned
to bio sent to each RAID device.
Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@intel.com>
Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Reviewed-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
"It's a pretty quiet round this time, which is nice. This contains:
- series from Bart, cleaning up the way we set/test/clear atomic
queue flags.
- series from Bart, fixing races between gendisk and queue
registration and removal.
- set of bcache fixes and improvements from various folks, by way of
Michael Lyle.
- set of lightnvm updates from Matias, most of it being the 1.2 to
2.0 transition.
- removal of unused DIO flags from Nikolay.
- blk-mq/sbitmap memory ordering fixes from Omar.
- divide-by-zero fix for BFQ from Paolo.
- minor documentation patches from Randy.
- timeout fix from Tejun.
- Alpha "can't write a char atomically" fix from Mikulas.
- set of NVMe fixes by way of Keith.
- bsg and bsg-lib improvements from Christoph.
- a few sed-opal fixes from Jonas.
- cdrom check-disk-change deadlock fix from Maurizio.
- various little fixes, comment fixes, etc from various folks"
* tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits)
blk-mq: Directly schedule q->timeout_work when aborting a request
blktrace: fix comment in blktrace_api.h
lightnvm: remove function name in strings
lightnvm: pblk: remove some unnecessary NULL checks
lightnvm: pblk: don't recover unwritten lines
lightnvm: pblk: implement 2.0 support
lightnvm: pblk: implement get log report chunk
lightnvm: pblk: rename ppaf* to addrf*
lightnvm: pblk: check for supported version
lightnvm: implement get log report chunk helpers
lightnvm: make address conversions depend on generic device
lightnvm: add support for 2.0 address format
lightnvm: normalize geometry nomenclature
lightnvm: complete geo structure with maxoc*
lightnvm: add shorten OCSSD version in geo
lightnvm: add minor version to generic geometry
lightnvm: simplify geometry structure
lightnvm: pblk: refactor init/exit sequences
lightnvm: Avoid validation of default op value
lightnvm: centralize permission check for lightnvm ioctl
...
This patch has been generated as follows:
for verb in set_unlocked clear_unlocked set clear; do
replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \
$(git grep -lw queue_flag_${verb} drivers block/bsg*)
done
Except for protecting all queue flag changes with the queue lock
this patch does not change any functionality.
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
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>
Don't use shrinker.nr_deferred to check whether shrinker was
initialized or not. Now this check was integrated into
unregister_shrinker(), so it is safe to call it against
unregistered shrinker.
Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
In order to provide data consistency with PPL for disks with write-back
cache enabled all data has to be flushed to disks before next PPL
entry. The disks to be flushed are marked in the bitmap. It's modified
under a mutex and it's only read after PPL io unit is submitted.
A limitation of 64 disks in the array has been introduced to keep data
structures and implementation simple. RAID5 arrays with so many disks are
not likely due to high risk of multiple disks failure. Such restriction
should not be a real life limitation.
With write-back cache disabled next PPL entry is submitted when data write
for current one completes. Data flush defers next log submission so trigger
it when there are no stripes for handling found.
As PPL assures all data is flushed to disk at request completion, just
acknowledge flush request when PPL is enabled.
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
In do_md_run(), md threads should not wake up until the array is fully
initialized in md_run(). However, in raid5_run(), raid5-cache may wake
up mddev->thread to flush stripes that need to be written back. This
design doesn't break badly right now. But it could lead to bad bug in
the future.
This patch tries to resolve this problem by splitting start up work
into two personality functions, run() and start(). Tasks that do not
require the md threads should go into run(), while task that require
the md threads go into start().
r5l_load_log() is moved to raid5_start(), so it is not called until
the md threads are started in do_md_run().
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
When disk failure occurs on new disks for reshape, mddev->degraded
is not calculated correctly. Faulty bit of the failure device is not
set before raid5_calc_degraded(conf).
mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/loop[012]
mdadm /dev/md0 -a /dev/loop3
mdadm /dev/md0 --grow -n4
mdadm /dev/md0 -f /dev/loop3 # simulating disk failure
cat /sys/block/md0/md/degraded # it outputs 0, but it should be 1.
However, mdadm -D /dev/md0 will show that it is degraded. It's a bug.
It can be fixed by moving the resources raid5_calc_degraded() depends
on before it.
Reported-by: Roy Chung <roychung@synology.com>
Reviewed-by: Alex Wu <alexwu@synology.com>
Signed-off-by: BingJing Chang <bingjingc@synology.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Pull MD update from Shaohua Li:
"This update mostly includes bug fixes:
- md-cluster now supports raid10 from Guoqing
- raid5 PPL fixes from Artur
- badblock regression fix from Bo
- suspend hang related fixes from Neil
- raid5 reshape fixes from Neil
- raid1 freeze deadlock fix from Nate
- memleak fixes from Zdenek
- bitmap related fixes from Me and Tao
- other fixes and cleanups"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (33 commits)
md: free unused memory after bitmap resize
md: release allocated bitset sync_set
md/bitmap: clear BITMAP_WRITE_ERROR bit before writing it to sb
md: be cautious about using ->curr_resync_completed for ->recovery_offset
badblocks: fix wrong return value in badblocks_set if badblocks are disabled
md: don't check MD_SB_CHANGE_CLEAN in md_allow_write
md-cluster: update document for raid10
md: remove redundant variable q
raid1: remove obsolete code in raid1_write_request
md-cluster: Use a small window for raid10 resync
md-cluster: Suspend writes in RAID10 if within range
md-cluster/raid10: set "do_balance = 0" if area is resyncing
md: use lockdep_assert_held
raid1: prevent freeze_array/wait_all_barriers deadlock
md: use TASK_IDLE instead of blocking signals
md: remove special meaning of ->quiesce(.., 2)
md: allow metadata update while suspending.
md: use mddev_suspend/resume instead of ->quiesce()
md: move suspend_hi/lo handling into core md code
md: don't call bitmap_create() while array is quiesced.
...
The ->recovery_offset shows how much of a non-InSync device is actually
in sync - how much has been recoveryed.
When performing a recovery, ->curr_resync and ->curr_resync_completed
follow the device address being recovered and so can be used to update
->recovery_offset.
When performing a reshape, ->curr_resync* might follow the device
addresses (raid5) or might follow array addresses (raid10), so cannot
in general be used to set ->recovery_offset. When reshaping backwards,
->curre_resync* measures from the *end* of the array-or-device, so is
particularly unhelpful.
So change the common code in md.c to only use ->curr_resync_complete
for the simple recovery case, and add code to raid5.c to update
->recovery_offset during a forwards reshape.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Hi - I submit this patch for the next merge window:
Some times ago, I made a patch f9c79bc05a that blocks signals around the
schedule() calls in MD. The MD subsystem needs to do an uninterruptible
sleep that is not accounted in load average - so we block signals and use
interruptible sleep.
The kernel has a special TASK_IDLE state for this purpose, so we can use
it instead of blocking signals. This patch doesn't fix any bug, it just
makes the code simpler.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The '2' argument means "wake up anything that is waiting".
This is an inelegant part of the design and was added
to help support management of suspend_lo/suspend_hi setting.
Now that suspend_lo/hi is managed in mddev_suspend/resume,
that need is gone.
These is still a couple of places where we call 'quiesce'
with an argument of '2', but they can safely be changed to
call ->quiesce(.., 1); ->quiesce(.., 0) which
achieve the same result at the small cost of pausing IO
briefly.
This removes a small "optimization" from suspend_{hi,lo}_store,
but it isn't clear that optimization served a useful purpose.
The code now is a lot clearer.
Suggested-by: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
responding to ->suspend_lo and ->suspend_hi is similar
to responding to ->suspended. It is best to wait in
the common core code without incrementing ->active_io.
This allows mddev_suspend()/mddev_resume() to work while
requests are waiting for suspend_lo/hi to change.
This is will be important after a subsequent patch
which uses mddev_suspend() to synchronize updating for
suspend_lo/hi.
So move the code for testing suspend_lo/hi out of raid1.c
and raid5.c, and place it in md.c
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Having both a bitmap and a journal is pointless.
Attempting to do so can corrupt the bitmap if the journal
replay happens before the bitmap is initialized.
Rather than try to avoid this corruption, simply
refuse to allow arrays with both a bitmap and a journal.
So:
- if raid5_run sees both are present, fail.
- if adding a bitmap finds a journal is present, fail
- if adding a journal finds a bitmap is present, fail.
Cc: stable@vger.kernel.org (4.10+)
Signed-off-by: NeilBrown <neilb@suse.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.
However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:
----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()
// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch
virtual patch
@ depends on patch @
expression E1, E2;
@@
- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)
@ depends on patch @
expression E;
@@
- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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>
Motivated by the desire to illiminate the imprecise nature of
DM-specific patches being unnecessarily sent to both the MD maintainer
and mailing-list. Which is born out of the fact that DM files also
reside in drivers/md/
Now all MD-specific files in drivers/md/ start with either "raid" or
"md-" and the MAINTAINERS file has been updated accordingly.
Shaohua: don't change module name
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
static checker reports a potential integer overflow. Cap the worker count to
avoid the overflow.
Reported:-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Pull MD fixes from Shaohua Li:
"Two small patches to fix long-lived raid5 stripe batch bugs, one from
Dennis and the other from me"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
md/raid5: preserve STRIPE_ON_UNPLUG_LIST in break_stripe_batch_list
md/raid5: fix a race condition in stripe batch
Pull MD updates from Shaohua Li:
"This update mainly fixes bugs:
- Make raid5 ppl support several ppl from Pawel
- Several raid5-cache bug fixes from Song
- Bitmap fixes from Neil and Me
- One raid1/10 regression fix since 4.12 from Me
- Other small fixes and cleanup"
* tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
md/bitmap: disable bitmap_resize for file-backed bitmaps.
raid5-ppl: Recovery support for multiple partial parity logs
md: Runtime support for multiple ppls
md/raid0: attach correct cgroup info in bio
lib/raid6: align AVX512 constants to 512 bits, not bytes
raid5: remove raid5_build_block
md/r5cache: call mddev_lock/unlock() in r5c_journal_mode_show
md: replace seq_release_private with seq_release
md: notify about new spare disk in the container
md/raid1/10: reset bio allocated from mempool
md/raid5: release/flush io in raid5_do_work()
md/bitmap: copy correct data for bitmap super
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>
Cc: stable@vger.kernel.org (v4.1+)
Signed-off-by: Shaohua Li <shli@fb.com>
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>
Cc: stable@vger.kernel.org (v4.1+)
Signed-off-by: Shaohua Li <shli@fb.com>
Increase PPL area to 1MB and use it as circular buffer to store PPL. The
entry with highest generation number is the latest one. If PPL to be
written is larger then space left in a buffer, rewind the buffer to the
start (don't wrap it).
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Now raid5_build_block is just called to set the
sector of r5dev, raid5_compute_blocknr can be
used directly for the purpose.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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+
Cc: stable@vger.kernel.org (4.4+)
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This way we don't need a block_device structure to submit I/O. The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open. Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).
For the actual I/O path all that we need is the gendisk, which exists
once per block device. But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.
Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The block layer always remaps partitions before calling into the
->make_request methods of drivers. Thus the call to get_start_sect in
in_chunk_boundary will always return 0 and can be removed.
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fb.com>
Since bio_io_error sets bi_status to BLK_STS_IOERR,
and calls bio_endio, so we can use it directly.
And as mentioned by Shaohua, there are also two
places in raid5.c can use bio_io_error either.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fb.com>
Pull MD update from Shaohua Li:
- fixed deadlock in MD suspend and a potential bug in bio allocation
(Neil Brown)
- fixed signal issue (Mikulas Patocka)
- fixed typo in FailFast test (Guoqing Jiang)
- other trival fixes
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
MD: fix sleep in atomic
MD: fix a null dereference
md: use a separate bio_set for synchronous IO.
md: change the initialization value for a spare device spot to MD_DISK_ROLE_SPARE
md/raid1: remove unused bio in sync_request_write
md/raid10: fix FailFast test for wrong device
md: don't use flush_signals in userspace processes
md: fix deadlock between mddev_suspend() and md_write_start()
"flags" arguments are often seen as good API design as they allow
easy extensibility.
bioset_create_nobvec() is implemented internally as a variation in
flags passed to __bioset_create().
To support future extension, make the internal structure part of the
API.
i.e. add a 'flags' argument to bioset_create() and discard
bioset_create_nobvec().
Note that the bio_split allocations in drivers/md/raid* do not need
the bvec mempool - they should have used bioset_create_nobvec().
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Cc: stable@vger.kernel.org
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
If mddev_suspend() races with md_write_start() we can deadlock
with mddev_suspend() waiting for the request that is currently
in md_write_start() to complete the ->make_request() call,
and md_write_start() waiting for the metadata to be updated
to mark the array as 'dirty'.
As metadata updates done by md_check_recovery() only happen then
the mddev_lock() can be claimed, and as mddev_suspend() is often
called with the lock held, these threads wait indefinitely for each
other.
We fix this by having md_write_start() abort if mddev_suspend()
is happening, and ->make_request() aborts if md_write_start()
aborted.
md_make_request() can detect this abort, decrease the ->active_io
count, and wait for mddev_suspend().
Reported-by: Nix <nix@esperi.org.uk>
Fix: 68866e425be2(MD: no sync IO while suspended)
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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Merge tag 'v4.12-rc5' into for-4.13/block
We've already got a few conflicts and upcoming work depends on some of the
changes that have gone into mainline as regression fixes for this series.
Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream
trees to continue working on 4.13 changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The new per-cpu counter for writes_pending is initialised in
md_alloc(), which is not called by dm-raid.
So dm-raid fails when md_write_start() is called.
Move the initialization to the personality modules
that need it. This way it is always initialised when needed,
but isn't unnecessarily initialized (requiring memory allocation)
when the personality doesn't use writes_pending.
Reported-by: Heinz Mauelshagen <heinzm@redhat.com>
Fixes: 4ad23a9764 ("MD: use per-cpu counter for writes_pending")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This makes it possible, with appropriate filesystem support, for a
sysadmin to tell what is affected by the mismatch, and whether
it should be ignored (if it's inside a swap partition, for
instance).
We ratelimit to prevent log flooding: if there are so many
mismatches that ratelimiting is necessary, the individual messages
are relatively unlikely to be important (either the machine is
swapping like crazy or something is very wrong with the disk).
Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Signed-off-by: Shaohua Li <shli@fb.com>
