sfrench/cifs-2.6.git
4 years agobcache: move closure debug file into debug directory
Chengguang Xu [Mon, 19 Mar 2018 00:36:23 +0000 (17:36 -0700)]
bcache: move closure debug file into debug directory

In current code closure debug file is outside of debug directory
and when unloading module there is lack of removing operation
for closure debug file, so it will cause creating error when trying
to reload  module.

This patch move closure debug file into "bcache" debug direcory
so that the file can get deleted properly.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: fix using of loop variable in memory shrink
Tang Junhui [Mon, 19 Mar 2018 00:36:22 +0000 (17:36 -0700)]
bcache: fix using of loop variable in memory shrink

In bch_mca_scan(), There are some confusion and logical error in the use of
loop variables. In this patch, we clarify them as:
1) nr: the number of btree nodes needs to scan, which will decrease after
we scan a btree node, and should not be less than 0;
2) i: the number of btree nodes have scanned, includes both
btree_cache_freeable and btree_cache, which should not be bigger than
btree_cache_used;
3) freed: the number of btree nodes have freed.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: fix error return value in memory shrink
Tang Junhui [Mon, 19 Mar 2018 00:36:21 +0000 (17:36 -0700)]
bcache: fix error return value in memory shrink

In bch_mca_scan(), the return value should not be the number of freed btree
nodes, but the number of pages of freed btree nodes.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: fix incorrect sysfs output value of strip size
Tang Junhui [Mon, 19 Mar 2018 00:36:20 +0000 (17:36 -0700)]
bcache: fix incorrect sysfs output value of strip size

Stripe size is shown as zero when no strip in back end device:
[root@ceph132 ~]# cat /sys/block/sdd/bcache/stripe_size
0.0k

Actually it should be 1T Bytes (1 << 31 sectors), but in sysfs
interface, stripe_size was changed from sectors to bytes, and move
9 bits left, so the 32 bits variable overflows.

This patch change the variable to a 64 bits type before moving bits.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: fix inaccurate io state for detached bcache devices
Tang Junhui [Mon, 19 Mar 2018 00:36:19 +0000 (17:36 -0700)]
bcache: fix inaccurate io state for detached bcache devices

When we run IO in a detached device,  and run iostat to shows IO status,
normally it will show like bellow (Omitted some fields):
Device: ... avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sdd        ... 15.89     0.53    1.82    0.20    2.23   1.81  52.30
bcache0    ... 15.89   115.42    0.00    0.00    0.00   2.40  69.60
but after IO stopped, there are still very big avgqu-sz and %util
values as bellow:
Device: ... avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
bcache0   ...      0   5326.32    0.00    0.00    0.00   0.00 100.10

The reason for this issue is that, only generic_start_io_acct() called
and no generic_end_io_acct() called for detached device in
cached_dev_make_request(). See the code:
//start generic_start_io_acct()
generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0);
if (cached_dev_get(dc)) {
//will callback generic_end_io_acct()
}
else {
//will not call generic_end_io_acct()
}

This patch calls generic_end_io_acct() in the end of IO for detached
devices, so we can show IO state correctly.

(Modified to use GFP_NOIO in kzalloc() by Coly Li)

Changelog:
v2: fix typo.
v1: the initial version.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: add stop_when_cache_set_failed option to backing device
Coly Li [Mon, 19 Mar 2018 00:36:18 +0000 (17:36 -0700)]
bcache: add stop_when_cache_set_failed option to backing device

When there are too many I/O errors on cache device, current bcache code
will retire the whole cache set, and detach all bcache devices. But the
detached bcache devices are not stopped, which is problematic when bcache
is in writeback mode.

If the retired cache set has dirty data of backing devices, continue
writing to bcache device will write to backing device directly. If the
LBA of write request has a dirty version cached on cache device, next time
when the cache device is re-registered and backing device re-attached to
it again, the stale dirty data on cache device will be written to backing
device, and overwrite latest directly written data. This situation causes
a quite data corruption.

But we cannot simply stop all attached bcache devices when the cache set is
broken or disconnected. For example, use bcache to accelerate performance
of an email service. In such workload, if cache device is broken but no
dirty data lost, keep the bcache device alive and permit email service
continue to access user data might be a better solution for the cache
device failure.

Nix <nix@esperi.org.uk> points out the issue and provides the above example
to explain why it might be necessary to not stop bcache device for broken
cache device. Pavel Goran <via-bcache@pvgoran.name> provides a brilliant
suggestion to provide "always" and "auto" options to per-cached device
sysfs file stop_when_cache_set_failed. If cache set is retiring and the
backing device has no dirty data on cache, it should be safe to keep the
bcache device alive. In this case, if stop_when_cache_set_failed is set to
"auto", the device failure handling code will not stop this bcache device
and permit application to access the backing device with a unattached
bcache device.

Changelog:
[mlyle: edited to not break string constants across lines]
v3: fix typos pointed out by Nix.
v2: change option values of stop_when_cache_set_failed from 1/0 to
    "auto"/"always".
v1: initial version, stop_when_cache_set_failed can be 0 (not stop) or 1
    (always stop).

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Cc: Nix <nix@esperi.org.uk>
Cc: Pavel Goran <via-bcache@pvgoran.name>
Cc: Junhui Tang <tang.junhui@zte.com.cn>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: add CACHE_SET_IO_DISABLE to struct cache_set flags
Coly Li [Mon, 19 Mar 2018 00:36:17 +0000 (17:36 -0700)]
bcache: add CACHE_SET_IO_DISABLE to struct cache_set flags

When too many I/Os failed on cache device, bch_cache_set_error() is called
in the error handling code path to retire whole problematic cache set. If
new I/O requests continue to come and take refcount dc->count, the cache
set won't be retired immediately, this is a problem.

Further more, there are several kernel thread and self-armed kernel work
may still running after bch_cache_set_error() is called. It needs to wait
quite a while for them to stop, or they won't stop at all. They also
prevent the cache set from being retired.

The solution in this patch is, to add per cache set flag to disable I/O
request on this cache and all attached backing devices. Then new coming I/O
requests can be rejected in *_make_request() before taking refcount, kernel
threads and self-armed kernel worker can stop very fast when flags bit
CACHE_SET_IO_DISABLE is set.

Because bcache also do internal I/Os for writeback, garbage collection,
bucket allocation, journaling, this kind of I/O should be disabled after
bch_cache_set_error() is called. So closure_bio_submit() is modified to
check whether CACHE_SET_IO_DISABLE is set on cache_set->flags. If set,
closure_bio_submit() will set bio->bi_status to BLK_STS_IOERR and
return, generic_make_request() won't be called.

A sysfs interface is also added to set or clear CACHE_SET_IO_DISABLE bit
from cache_set->flags, to disable or enable cache set I/O for debugging. It
is helpful to trigger more corner case issues for failed cache device.

Changelog
v4, add wait_for_kthread_stop(), and call it before exits writeback and gc
    kernel threads.
v3, change CACHE_SET_IO_DISABLE from 4 to 3, since it is bit index.
    remove "bcache: " prefix when printing out kernel message.
v2, more changes by previous review,
- Use CACHE_SET_IO_DISABLE of cache_set->flags, suggested by Junhui.
- Check CACHE_SET_IO_DISABLE in bch_btree_gc() to stop a while-loop, this
  is reported and inspired from origal patch of Pavel Vazharov.
v1, initial version.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Cc: Junhui Tang <tang.junhui@zte.com.cn>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Pavel Vazharov <freakpv@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: stop dc->writeback_rate_update properly
Coly Li [Mon, 19 Mar 2018 00:36:16 +0000 (17:36 -0700)]
bcache: stop dc->writeback_rate_update properly

struct delayed_work writeback_rate_update in struct cache_dev is a delayed
worker to call function update_writeback_rate() in period (the interval is
defined by dc->writeback_rate_update_seconds).

When a metadate I/O error happens on cache device, bcache error handling
routine bch_cache_set_error() will call bch_cache_set_unregister() to
retire whole cache set. On the unregister code path, this delayed work is
stopped by calling cancel_delayed_work_sync(&dc->writeback_rate_update).

dc->writeback_rate_update is a special delayed work from others in bcache.
In its routine update_writeback_rate(), this delayed work is re-armed
itself. That means when cancel_delayed_work_sync() returns, this delayed
work can still be executed after several seconds defined by
dc->writeback_rate_update_seconds.

The problem is, after cancel_delayed_work_sync() returns, the cache set
unregister code path will continue and release memory of struct cache set.
Then the delayed work is scheduled to run, __update_writeback_rate()
will reference the already released cache_set memory, and trigger a NULL
pointer deference fault.

This patch introduces two more bcache device flags,
- BCACHE_DEV_WB_RUNNING
  bit set:  bcache device is in writeback mode and running, it is OK for
            dc->writeback_rate_update to re-arm itself.
  bit clear:bcache device is trying to stop dc->writeback_rate_update,
            this delayed work should not re-arm itself and quit.
- BCACHE_DEV_RATE_DW_RUNNING
  bit set:  routine update_writeback_rate() is executing.
  bit clear: routine update_writeback_rate() quits.

This patch also adds a function cancel_writeback_rate_update_dwork() to
wait for dc->writeback_rate_update quits before cancel it by calling
cancel_delayed_work_sync(). In order to avoid a deadlock by unexpected
quit dc->writeback_rate_update, after time_out seconds this function will
give up and continue to call cancel_delayed_work_sync().

And here I explain how this patch stops self re-armed delayed work properly
with the above stuffs.

update_writeback_rate() sets BCACHE_DEV_RATE_DW_RUNNING at its beginning
and clears BCACHE_DEV_RATE_DW_RUNNING at its end. Before calling
cancel_writeback_rate_update_dwork() clear flag BCACHE_DEV_WB_RUNNING.

Before calling cancel_delayed_work_sync() wait utill flag
BCACHE_DEV_RATE_DW_RUNNING is clear. So when calling
cancel_delayed_work_sync(), dc->writeback_rate_update must be already re-
armed, or quite by seeing BCACHE_DEV_WB_RUNNING cleared. In both cases
delayed work routine update_writeback_rate() won't be executed after
cancel_delayed_work_sync() returns.

Inside update_writeback_rate() before calling schedule_delayed_work(), flag
BCACHE_DEV_WB_RUNNING is checked before. If this flag is cleared, it means
someone is about to stop the delayed work. Because flag
BCACHE_DEV_RATE_DW_RUNNING is set already and cancel_delayed_work_sync()
has to wait for this flag to be cleared, we don't need to worry about race
condition here.

If update_writeback_rate() is scheduled to run after checking
BCACHE_DEV_RATE_DW_RUNNING and before calling cancel_delayed_work_sync()
in cancel_writeback_rate_update_dwork(), it is also safe. Because at this
moment BCACHE_DEV_WB_RUNNING is cleared with memory barrier. As I mentioned
previously, update_writeback_rate() will see BCACHE_DEV_WB_RUNNING is clear
and quit immediately.

Because there are more dependences inside update_writeback_rate() to struct
cache_set memory, dc->writeback_rate_update is not a simple self re-arm
delayed work. After trying many different methods (e.g. hold dc->count, or
use locks), this is the only way I can find which works to properly stop
dc->writeback_rate_update delayed work.

Changelog:
v3: change values of BCACHE_DEV_WB_RUNNING and BCACHE_DEV_RATE_DW_RUNNING
    to bit index, for test_bit().
v2: Try to fix the race issue which is pointed out by Junhui.
v1: The initial version for review

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Junhui Tang <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set
Coly Li [Mon, 19 Mar 2018 00:36:15 +0000 (17:36 -0700)]
bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set

In patch "bcache: fix cached_dev->count usage for bch_cache_set_error()",
cached_dev_get() is called when creating dc->writeback_thread, and
cached_dev_put() is called when exiting dc->writeback_thread. This
modification works well unless people detach the bcache device manually by
    'echo 1 > /sys/block/bcache<N>/bcache/detach'
Because this sysfs interface only calls bch_cached_dev_detach() which wakes
up dc->writeback_thread but does not stop it. The reason is, before patch
"bcache: fix cached_dev->count usage for bch_cache_set_error()", inside
bch_writeback_thread(), if cache is not dirty after writeback,
cached_dev_put() will be called here. And in cached_dev_make_request() when
a new write request makes cache from clean to dirty, cached_dev_get() will
be called there. Since we don't operate dc->count in these locations,
refcount d->count cannot be dropped after cache becomes clean, and
cached_dev_detach_finish() won't be called to detach bcache device.

This patch fixes the issue by checking whether BCACHE_DEV_DETACHING is
set inside bch_writeback_thread(). If this bit is set and cache is clean
(no existing writeback_keys), break the while-loop, call cached_dev_put()
and quit the writeback thread.

Please note if cache is still dirty, even BCACHE_DEV_DETACHING is set the
writeback thread should continue to perform writeback, this is the original
design of manually detach.

It is safe to do the following check without locking, let me explain why,
+ if (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) &&
+     (!atomic_read(&dc->has_dirty) || !dc->writeback_running)) {

If the kenrel thread does not sleep and continue to run due to conditions
are not updated in time on the running CPU core, it just consumes more CPU
cycles and has no hurt. This should-sleep-but-run is safe here. We just
focus on the should-run-but-sleep condition, which means the writeback
thread goes to sleep in mistake while it should continue to run.
1, First of all, no matter the writeback thread is hung or not,
   kthread_stop() from cached_dev_detach_finish() will wake up it and
   terminate by making kthread_should_stop() return true. And in normal
   run time, bit on index BCACHE_DEV_DETACHING is always cleared, the
   condition
!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)
   is always true and can be ignored as constant value.
2, If one of the following conditions is true, the writeback thread should
   go to sleep,
   "!atomic_read(&dc->has_dirty)" or "!dc->writeback_running)"
   each of them independently controls the writeback thread should sleep or
   not, let's analyse them one by one.
2.1 condition "!atomic_read(&dc->has_dirty)"
   If dc->has_dirty is set from 0 to 1 on another CPU core, bcache will
   call bch_writeback_queue() immediately or call bch_writeback_add() which
   indirectly calls bch_writeback_queue() too. In bch_writeback_queue(),
   wake_up_process(dc->writeback_thread) is called. It sets writeback
   thread's task state to TASK_RUNNING and following an implicit memory
   barrier, then tries to wake up the writeback thread.
   In writeback thread, its task state is set to TASK_INTERRUPTIBLE before
   doing the condition check. If other CPU core sets the TASK_RUNNING state
   after writeback thread setting TASK_INTERRUPTIBLE, the writeback thread
   will be scheduled to run very soon because its state is not
   TASK_INTERRUPTIBLE. If other CPU core sets the TASK_RUNNING state before
   writeback thread setting TASK_INTERRUPTIBLE, the implict memory barrier
   of wake_up_process() will make sure modification of dc->has_dirty on
   other CPU core is updated and observed on the CPU core of writeback
   thread. Therefore the condition check will correctly be false, and
   continue writeback code without sleeping.
2.2 condition "!dc->writeback_running)"
   dc->writeback_running can be changed via sysfs file, every time it is
   modified, a following bch_writeback_queue() is alwasy called. So the
   change is always observed on the CPU core of writeback thread. If
   dc->writeback_running is changed from 0 to 1 on other CPU core, this
   condition check will observe the modification and allow writeback
   thread to continue to run without sleeping.
Now we can see, even without a locking protection, multiple conditions
check is safe here, no deadlock or process hang up will happen.

I compose a separte patch because that patch "bcache: fix cached_dev->count
usage for bch_cache_set_error()" already gets a "Reviewed-by:" from Hannes
Reinecke. Also this fix is not trivial and good for a separate patch.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Huijun Tang <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: fix cached_dev->count usage for bch_cache_set_error()
Coly Li [Mon, 19 Mar 2018 00:36:14 +0000 (17:36 -0700)]
bcache: fix cached_dev->count usage for bch_cache_set_error()

When bcache metadata I/O fails, bcache will call bch_cache_set_error()
to retire the whole cache set. The expected behavior to retire a cache
set is to unregister the cache set, and unregister all backing device
attached to this cache set, then remove sysfs entries of the cache set
and all attached backing devices, finally release memory of structs
cache_set, cache, cached_dev and bcache_device.

In my testing when journal I/O failure triggered by disconnected cache
device, sometimes the cache set cannot be retired, and its sysfs
entry /sys/fs/bcache/<uuid> still exits and the backing device also
references it. This is not expected behavior.

When metadata I/O failes, the call senquence to retire whole cache set is,
        bch_cache_set_error()
        bch_cache_set_unregister()
        bch_cache_set_stop()
        __cache_set_unregister()     <- called as callback by calling
                                        clousre_queue(&c->caching)
        cache_set_flush()            <- called as a callback when refcount
                                        of cache_set->caching is 0
        cache_set_free()             <- called as a callback when refcount
                                        of catch_set->cl is 0
        bch_cache_set_release()      <- called as a callback when refcount
                                        of catch_set->kobj is 0

I find if kernel thread bch_writeback_thread() quits while-loop when
kthread_should_stop() is true and searched_full_index is false, clousre
callback cache_set_flush() set by continue_at() will never be called. The
result is, bcache fails to retire whole cache set.

cache_set_flush() will be called when refcount of closure c->caching is 0,
and in function bcache_device_detach() refcount of closure c->caching is
released to 0 by clousre_put(). In metadata error code path, function
bcache_device_detach() is called by cached_dev_detach_finish(). This is a
callback routine being called when cached_dev->count is 0. This refcount
is decreased by cached_dev_put().

The above dependence indicates, cache_set_flush() will be called when
refcount of cache_set->cl is 0, and refcount of cache_set->cl to be 0
when refcount of cache_dev->count is 0.

The reason why sometimes cache_dev->count is not 0 (when metadata I/O fails
and bch_cache_set_error() called) is, in bch_writeback_thread(), refcount
of cache_dev is not decreased properly.

In bch_writeback_thread(), cached_dev_put() is called only when
searched_full_index is true and cached_dev->writeback_keys is empty, a.k.a
there is no dirty data on cache. In most of run time it is correct, but
when bch_writeback_thread() quits the while-loop while cache is still
dirty, current code forget to call cached_dev_put() before this kernel
thread exits. This is why sometimes cache_set_flush() is not executed and
cache set fails to be retired.

The reason to call cached_dev_put() in bch_writeback_rate() is, when the
cache device changes from clean to dirty, cached_dev_get() is called, to
make sure during writeback operatiions both backing and cache devices
won't be released.

Adding following code in bch_writeback_thread() does not work,
   static int bch_writeback_thread(void *arg)
        }

+       if (atomic_read(&dc->has_dirty))
+               cached_dev_put()
+
        return 0;
 }
because writeback kernel thread can be waken up and start via sysfs entry:
        echo 1 > /sys/block/bcache<N>/bcache/writeback_running
It is difficult to check whether backing device is dirty without race and
extra lock. So the above modification will introduce potential refcount
underflow in some conditions.

The correct fix is, to take cached dev refcount when creating the kernel
thread, and put it before the kernel thread exits. Then bcache does not
need to take a cached dev refcount when cache turns from clean to dirty,
or to put a cached dev refcount when cache turns from ditry to clean. The
writeback kernel thread is alwasy safe to reference data structure from
cache set, cache and cached device (because a refcount of cache device is
taken for it already), and no matter the kernel thread is stopped by I/O
errors or system reboot, cached_dev->count can always be used correctly.

The patch is simple, but understanding how it works is quite complicated.

Changelog:
v2: set dc->writeback_thread to NULL in this patch, as suggested by Hannes.
v1: initial version for review.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Junhui Tang <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: bio_check_eod() needs to consider partitions
Christoph Hellwig [Wed, 14 Mar 2018 15:56:53 +0000 (16:56 +0100)]
block: bio_check_eod() needs to consider partitions

bio_check_eod() should check partition size not the whole disk if
bio->bi_partno is non-zero.  Do this by moving the call
to bio_check_eod() into blk_partition_remap().

Based on an earlier patch from Jiufei Xue.

Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index")
Reported-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h>
Bart Van Assche [Wed, 14 Mar 2018 22:48:06 +0000 (15:48 -0700)]
block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h>

It happens often while I'm preparing a patch for a block driver that
I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
available for this driver? Do I have to introduce definitions of these
constants before I can use these constants? To avoid this confusion,
move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
<linux/blkdev.h> header file such that these become available for all
block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
header file conditional to avoid that including that header file after
<linux/blkdev.h> causes the compiler to complain about a SECTOR_SIZE
redefinition.

Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
not been removed from uapi header files nor from NAND drivers in
which these constants are used for another purpose than converting
block layer offsets and sizes into a number of sectors.

Cc: David S. Miller <davem@davemloft.net>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq-debugfs: Show more request state information
Bart Van Assche [Fri, 16 Mar 2018 17:31:11 +0000 (10:31 -0700)]
blk-mq-debugfs: Show more request state information

Since commit 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages
from blk-mq") blk_rq_is_complete() only reports whether or not a
request has completed for legacy queues. Hence modify the
blk-mq-debugfs code such that it shows the blk-mq request state
again.

Fixes: 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()
Joseph Qi [Fri, 16 Mar 2018 06:51:27 +0000 (14:51 +0800)]
blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()

We've triggered a WARNING in blk_throtl_bio() when throttling writeback
io, which complains blkg->refcnt is already 0 when calling blkg_get(),
and then kernel crashes with invalid page request.
After investigating this issue, we've found it is caused by a race
between blkcg_bio_issue_check() and cgroup_rmdir(), which is described
below:

writeback kworker               cgroup_rmdir
                                  cgroup_destroy_locked
                                    kill_css
                                      css_killed_ref_fn
                                        css_killed_work_fn
                                          offline_css
                                            blkcg_css_offline
  blkcg_bio_issue_check
    rcu_read_lock
    blkg_lookup
                                              spin_trylock(q->queue_lock)
                                              blkg_destroy
                                              spin_unlock(q->queue_lock)
    blk_throtl_bio
    spin_lock_irq(q->queue_lock)
    ...
    spin_unlock_irq(q->queue_lock)
  rcu_read_unlock

Since rcu can only prevent blkg from releasing when it is being used,
the blkg->refcnt can be decreased to 0 during blkg_destroy() and schedule
blkg release.
Then trying to blkg_get() in blk_throtl_bio() will complains the WARNING.
And then the corresponding blkg_put() will schedule blkg release again,
which result in double free.
This race is introduced by commit ae1188963611 ("blkcg: consolidate blkg
creation in blkcg_bio_issue_check()"). Before this commit, it will
lookup first and then try to lookup/create again with queue_lock. Since
revive this logic is a bit drastic, so fix it by only offlining pd during
blkcg_css_offline(), and move the rest destruction (especially
blkg_put()) into blkcg_css_free(), which should be the right way as
discussed.

Fixes: ae1188963611 ("blkcg: consolidate blkg creation in blkcg_bio_issue_check()")
Reported-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: sed-opal: fix u64 short atom length
Jonas Rabenstein [Wed, 7 Mar 2018 16:55:56 +0000 (17:55 +0100)]
block: sed-opal: fix u64 short atom length

The length must be given as bytes and not as 4 bit tuples.

Reviewed-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobsg: split handling of SCSI CDBs vs transport requeues
Christoph Hellwig [Tue, 13 Mar 2018 16:28:41 +0000 (17:28 +0100)]
bsg: split handling of SCSI CDBs vs transport requeues

The current BSG design tries to shoe-horn the transport-specific
passthrough commands into the overall framework for SCSI passthrough
requests.  This has a couple problems:

 - each passthrough queue has to set the QUEUE_FLAG_SCSI_PASSTHROUGH flag
   despite not dealing with SCSI commands at all.  Because of that these
   queues could also incorrectly accept SCSI commands from in-kernel
   users or through the legacy SCSI_IOCTL_SEND_COMMAND ioctl.
 - the real SCSI bsg queues also incorrectly accept bsg requests of the
   BSG_SUB_PROTOCOL_SCSI_TRANSPORT type
 - the bsg transport code is almost unredable because it tries to reuse
   different SCSI concepts for its own purpose.

This patch instead adds a new bsg_ops structure to handle the two cases
differently, and thus solves all of the above problems.  Another side
effect is that the bsg-lib queues also don't need to embedd a
struct scsi_request anymore.

Signed-off-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@kernel.dk>
4 years agobsg-lib: remove bsg_job.req
Christoph Hellwig [Tue, 13 Mar 2018 16:28:40 +0000 (17:28 +0100)]
bsg-lib: remove bsg_job.req

Users of the bsg-lib interface should only use the bsg_job data structure
and not know about implementation details of it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobsg-lib: introduce a timeout field in struct bsg_job
Christoph Hellwig [Tue, 13 Mar 2018 16:28:39 +0000 (17:28 +0100)]
bsg-lib: introduce a timeout field in struct bsg_job

The zfcp driver wants to know the timeout for a bsg job, so add a field
to struct bsg_job for it in preparation of not exposing the request
to the bsg-lib users.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agodirect-io: Remove unused DIO_SKIP_DIO_COUNT logic
Nikolay Borisov [Fri, 23 Feb 2018 11:45:29 +0000 (13:45 +0200)]
direct-io: Remove unused DIO_SKIP_DIO_COUNT logic

This flag was added by fe0f07d08ee3 ("direct-io: only inc/deci
inode->i_dio_count for file systems") as means to optimise the atomic
modificaiton of the variable for blockdevices. However with the advent
of 542ff7bf18c6 ("block: new direct I/O implementation") it became
unused. So let's remove it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agodirect-io: Remove unused DIO_ASYNC_EXTEND flag
Nikolay Borisov [Fri, 23 Feb 2018 11:45:28 +0000 (13:45 +0200)]
direct-io: Remove unused DIO_ASYNC_EXTEND flag

This flag was added by 6039257378e4 ("direct-io: add flag to allow aio
writes beyond i_size") to support XFS. However, with the rework of
XFS' DIO's path to use iomap in acdda3aae146 ("xfs: use iomap_dio_rw")
it became redundant. So let's remove it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoMAINTAINERS: add coverage for drivers/block
Ross Zwisler [Fri, 9 Mar 2018 16:38:26 +0000 (09:38 -0700)]
MAINTAINERS: add coverage for drivers/block

To help folks like me that use scripts/get_maintainer.pl.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Suppress kernel-doc warnings triggered by blk-zoned.c
Bart Van Assche [Thu, 8 Mar 2018 23:28:50 +0000 (15:28 -0800)]
block: Suppress kernel-doc warnings triggered by blk-zoned.c

Avoid that building with W=1 causes the kernel-doc tool to complain
about undocumented function arguments for the blk-zoned.c source file.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agocdrom: do not call check_disk_change() inside cdrom_open()
Maurizio Lombardi [Fri, 9 Mar 2018 12:59:06 +0000 (13:59 +0100)]
cdrom: do not call check_disk_change() inside cdrom_open()

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoDocumentation/cdrom: fix German sharp s in LaTex
Randy Dunlap [Sun, 28 Jan 2018 00:31:45 +0000 (16:31 -0800)]
Documentation/cdrom: fix German sharp s in LaTex

Apparently the LaTex abbreviation for the German "sharp s" (ß)
(Unicode U+00DF) has changed from {\sz} to {\ss}.  With {\sz},
I get this error at line 1016 (line number after another patch):

! Undefined control sequence.
l.1016 ...nel~2.0.  Further thanks to Heiko Ei{\sz
                                                  }feldt,

This is fixed by changing the {\sz} to {\ss}.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoDocumentation/cdrom: update cdrom-standard.tex for kernel changes
Randy Dunlap [Sat, 27 Jan 2018 03:58:16 +0000 (19:58 -0800)]
Documentation/cdrom: update cdrom-standard.tex for kernel changes

Documentation updates for Documentation/cdrom/cdrom-standard.tex:

cdrom_device_ops:
- add check_events() and generic_packet()

cdrom_device_info:
- add one 'const' modifier
- correct some field descriptions
- add some missing fields
- drop 'kdev_t dev;' field

Also drop <n_discs> sentence from documentation because it is not
referenced anywhere in the kernel header or C files.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Move the queue_flag_*() functions from a public into a private header file
Bart Van Assche [Thu, 8 Mar 2018 01:10:12 +0000 (17:10 -0800)]
block: Move the queue_flag_*() functions from a public into a private header file

This patch helps to avoid that new code gets introduced in block drivers
that manipulates queue flags without holding the queue lock when that
lock should be held.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Complain if queue_flag_(set|clear)_unlocked() is abused
Bart Van Assche [Thu, 8 Mar 2018 01:10:11 +0000 (17:10 -0800)]
block: Complain if queue_flag_(set|clear)_unlocked() is abused

Since it is not safe to use queue_flag_(set|clear)_unlocked()
without holding the queue lock after the sysfs entries for a
queue have been created, complain if this happens.

Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Use blk_queue_flag_*() in drivers instead of queue_flag_*()
Bart Van Assche [Thu, 8 Mar 2018 01:10:10 +0000 (17:10 -0800)]
block: Use blk_queue_flag_*() in drivers instead of queue_flag_*()

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>
4 years agotarget/tcm_loop: Use blk_queue_flag_set()
Bart Van Assche [Thu, 8 Mar 2018 01:10:09 +0000 (17:10 -0800)]
target/tcm_loop: Use blk_queue_flag_set()

Use blk_queue_flag_set() instead of open-coding this function.

Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoiscsi: Use blk_queue_flag_set()
Bart Van Assche [Thu, 8 Mar 2018 01:10:08 +0000 (17:10 -0800)]
iscsi: Use blk_queue_flag_set()

Use blk_queue_flag_set() instead of open-coding this function.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: Use the blk_queue_flag_{set,clear}() functions
Bart Van Assche [Thu, 8 Mar 2018 01:10:07 +0000 (17:10 -0800)]
bcache: Use the blk_queue_flag_{set,clear}() functions

Use the blk_queue_flag_{set,clear}() functions instead of open-coding
these.

Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agomtip32xx: Use the blk_queue_flag_*() functions
Bart Van Assche [Thu, 8 Mar 2018 01:10:06 +0000 (17:10 -0800)]
mtip32xx: Use the blk_queue_flag_*() functions

Use the blk_queue_flag_*() functions instead of open-coding these.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Protect queue flag changes with the queue lock
Bart Van Assche [Thu, 8 Mar 2018 01:10:05 +0000 (17:10 -0800)]
block: Protect queue flag changes with the queue lock

Since the queue flags may be changed concurrently from multiple
contexts after a queue becomes visible in sysfs, make these changes
safe by protecting these with the queue lock.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}()
Bart Van Assche [Thu, 8 Mar 2018 01:10:04 +0000 (17:10 -0800)]
block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}()

Introduce functions that modify the queue flags and that protect
these modifications with the request queue lock. Except for moving
one wake_up_all() call from inside to outside a critical section,
this patch does not change any functionality.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Use the queue_flag_*() functions instead of open-coding these
Bart Van Assche [Thu, 8 Mar 2018 01:10:03 +0000 (17:10 -0800)]
block: Use the queue_flag_*() functions instead of open-coding these

Except for changing the atomic queue flag manipulations that are
protected by the queue lock into non-atomic manipulations, this
patch does not change any functionality.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Reorder the queue flag manipulation function definitions
Bart Van Assche [Thu, 8 Mar 2018 01:10:02 +0000 (17:10 -0800)]
block: Reorder the queue flag manipulation function definitions

Move the definition of queue_flag_clear_unlocked() up and move the
definition of queue_in_flight() down such that all queue flag
manipulation function definitions become contiguous.

This patch does not change any functionality.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: sed-opal: fix response string extraction
Jonas Rabenstein [Thu, 1 Mar 2018 13:26:37 +0000 (14:26 +0100)]
block: sed-opal: fix response string extraction

Tokens are prefixed by a variable length of bytes. If a bytestring is
not stored in an tiny or short atom, we have to skip more than one byte
in order to have the actual bytes not prefixed by the bytes describing
the actual length of the string.

Acked-by: Jonathan Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: null_blk: fix 'Invalid parameters' when loading module
Ming Lei [Tue, 6 Mar 2018 04:07:13 +0000 (12:07 +0800)]
block: null_blk: fix 'Invalid parameters' when loading module

On ARM64, the default page size has been 64K on some distributions, and
we should allow ARM64 people to play null_blk.

This patch fixes the issue by extend page bitmap size for supporting
other non-4KB PAGE_SIZE.

Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Kyungchan Koh <kkc6196@fb.com>,
Cc: weiping zhang <zhangweiping@didichuxing.com>
Cc: Yi Zhang <yi.zhang@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agostaging: rts5208: rename SG_END macro
Arnd Bergmann [Thu, 1 Mar 2018 10:31:29 +0000 (11:31 +0100)]
staging: rts5208: rename SG_END macro

A change to the generic scatterlist code caused a conflict with
the rtsx card reader driver:

In file included from drivers/staging/rts5208/rtsx.h:180,
                 from drivers/staging/rts5208/rtsx.c:28:
drivers/staging/rts5208/rtsx_chip.h:343: error: "SG_END" redefined [-Werror]

This changes one instance of the driver to prefix SG_END and
related constants.

Fixes: 723fbf563a6a ("lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings")
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agomisc: rtsx: rename SG_END macro
Arnd Bergmann [Thu, 1 Mar 2018 10:31:28 +0000 (11:31 +0100)]
misc: rtsx: rename SG_END macro

A change to the generic scatterlist code caused a conflict with
the rtsx card reader driver:

In file included from drivers/misc/cardreader/rtsx_pcr.c:32:
include/linux/rtsx_pci.h:40: error: "SG_END" redefined [-Werror]

This changes one instance of the driver to prefix SG_END and
related constants.

Fixes: 723fbf563a6a ("lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings")
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Fix a race between request queue removal and the block cgroup controller
Bart Van Assche [Wed, 28 Feb 2018 18:15:33 +0000 (10:15 -0800)]
block: Fix a race between request queue removal and the block cgroup controller

Avoid that the following race can occur:

blk_cleanup_queue()               blkcg_print_blkgs()
  spin_lock_irq(lock) (1)           spin_lock_irq(blkg->q->queue_lock) (2,5)
    q->queue_lock = &q->__queue_lock (3)
  spin_unlock_irq(lock) (4)
                                    spin_unlock_irq(blkg->q->queue_lock) (6)

(1) take driver lock;
(2) busy loop for driver lock;
(3) override driver lock with internal lock;
(4) unlock driver lock;
(5) can take driver lock now;
(6) but unlock internal lock.

This change is safe because only the SCSI core and the NVME core keep
a reference on a request queue after having called blk_cleanup_queue().
Neither driver accesses any of the removed data structures between its
blk_cleanup_queue() and blk_put_queue() calls.

Reported-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Jan Kara <jack@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Fix a race between the cgroup code and request queue initialization
Bart Van Assche [Wed, 28 Feb 2018 18:15:32 +0000 (10:15 -0800)]
block: Fix a race between the cgroup code and request queue initialization

Initialize the request queue lock earlier such that the following
race can no longer occur:

blk_init_queue_node()             blkcg_print_blkgs()
  blk_alloc_queue_node (1)
    q->queue_lock = &q->__queue_lock (2)
    blkcg_init_queue(q) (3)
                                    spin_lock_irq(blkg->q->queue_lock) (4)
  q->queue_lock = lock (5)
                                    spin_unlock_irq(blkg->q->queue_lock) (6)

(1) allocate an uninitialized queue;
(2) initialize queue_lock to its default internal lock;
(3) initialize blkcg part of request queue, which will create blkg and
    then insert it to blkg_list;
(4) traverse blkg_list and find the created blkg, and then take its
    queue lock, here it is the default *internal lock*;
(5) *race window*, now queue_lock is overridden with *driver specified
    lock*;
(6) now unlock *driver specified lock*, not the locked *internal lock*,
    unlock balance breaks.

The changes in this patch are as follows:
- Move the .queue_lock initialization from blk_init_queue_node() into
  blk_alloc_queue_node().
- Only override the .queue_lock pointer for legacy queues because it
  is not useful for blk-mq queues to override this pointer.
- For all all block drivers that initialize .queue_lock explicitly,
  change the blk_alloc_queue() call in the driver into a
  blk_alloc_queue_node() call and remove the explicit .queue_lock
  initialization. Additionally, initialize the spin lock that will
  be used as queue lock earlier if necessary.

Reported-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Add 'lock' as third argument to blk_alloc_queue_node()
Bart Van Assche [Wed, 28 Feb 2018 18:15:31 +0000 (10:15 -0800)]
block: Add 'lock' as third argument to blk_alloc_queue_node()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agozram: Delete gendisk before cleaning up the request queue
Bart Van Assche [Wed, 28 Feb 2018 18:15:30 +0000 (10:15 -0800)]
zram: Delete gendisk before cleaning up the request queue

Remove the disk, partition and bdi sysfs attributes before cleaning up
the request queue associated with the disk.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agomd: Delete gendisk before cleaning up the request queue
Bart Van Assche [Wed, 28 Feb 2018 18:15:29 +0000 (10:15 -0800)]
md: Delete gendisk before cleaning up the request queue

Remove the disk, partition and bdi sysfs attributes before cleaning up
the request queue associated with the disk.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock/loop: Delete gendisk before cleaning up the request queue
Bart Van Assche [Wed, 28 Feb 2018 18:15:28 +0000 (10:15 -0800)]
block/loop: Delete gendisk before cleaning up the request queue

Remove the disk, partition and bdi sysfs attributes before cleaning up
the request queue associated with the disk.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: add 'requeue' fault attribute
Jens Axboe [Wed, 28 Feb 2018 16:18:57 +0000 (09:18 -0700)]
null_blk: add 'requeue' fault attribute

Similarly to the support we have for testing/faking timeouts for
null_blk, this adds support for triggering a requeue condition.
Considering the issues around restart we've been seeing, this should be
a useful addition to the testing arsenal to ensure that we are handling
requeue conditions correctly.

This works for queue mode 1 (legacy request_fn based path) and 2 (blk-mq
path), as there's no good way to do requeue with a bio based driver.
This is similar to the timeout path. For the blk-mq path, we alternate
between passing back BLK_STS_RESOURCE and manually calling
blk_mq_requeue_request() in the driver. The former will hit the core
requeue path, while the latter exercises the IO scheduler requeue
path.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agosbitmap: use test_and_set_bit_lock()/clear_bit_unlock()
Omar Sandoval [Wed, 28 Feb 2018 00:56:43 +0000 (16:56 -0800)]
sbitmap: use test_and_set_bit_lock()/clear_bit_unlock()

sbitmap_queue_get()/sbitmap_queue_clear() are used for
allocating/freeing a resource, so they should provide acquire/release
barrier semantics, respectively. sbitmap_get() currently contains a full
barrier, which is unnecessary, so use test_and_set_bit_lock() instead of
test_and_set_bit() (these are equivalent on x86_64). sbitmap_clear_bit()
does not imply any barriers, which is incorrect, as accesses of the
resource (e.g., request) could potentially get reordered to after the
clear_bit(). Introduce sbitmap_clear_bit_unlock() and use it for
sbitmap_queue_clear() (this only adds a compiler barrier on x86_64). The
other existing user of sbitmap_clear_bit() (the blk-mq software queue
pending map) is serialized through a spinlock and does not need this.

Reported-by: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: clear ctx pending bit under ctx lock
Omar Sandoval [Wed, 28 Feb 2018 00:56:42 +0000 (16:56 -0800)]
block: clear ctx pending bit under ctx lock

When we insert a request, we set the software queue pending bit while
holding the software queue lock. However, we clear it outside of the
lock, so it's possible that a concurrent insert could reset the bit
after we clear it but before we empty the request list. Afterwards, the
bit would still be set but the software queue wouldn't have any requests
in it, leading us to do a spurious run in the future. This is mostly a
benign/theoretical issue, but it makes the following change easier to
justify.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq-debugfs: Show zone locking information
Bart Van Assche [Wed, 28 Feb 2018 00:32:14 +0000 (16:32 -0800)]
blk-mq-debugfs: Show zone locking information

When debugging the ZBC code in the mq-deadline scheduler it is very
important to know which zones are locked and which zones are not
locked. Hence this patch that exports the zone locking information
through debugfs.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq-debugfs: Reorder queue show and store methods
Bart Van Assche [Wed, 28 Feb 2018 00:32:13 +0000 (16:32 -0800)]
blk-mq-debugfs: Reorder queue show and store methods

Make sure that the queue show and store methods are contiguous and
also that these appear in alphabetical order.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback: remove dead code in wb_blkcg/memcg_offline
Jiufei Xue [Wed, 28 Feb 2018 05:44:18 +0000 (13:44 +0800)]
writeback: remove dead code in wb_blkcg/memcg_offline

Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agolib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings
Anshuman Khandual [Thu, 15 Feb 2018 03:33:56 +0000 (09:03 +0530)]
lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings

This replaces scatterlist->page_link LSB encodings with SG_CHAIN and
SG_END definitions without any functional change.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoMerge branch 'for-jens' of git://git.infradead.org/nvme into for-linus
Jens Axboe [Wed, 28 Feb 2018 19:18:58 +0000 (12:18 -0700)]
Merge branch 'for-jens' of git://git.infradead.org/nvme into for-linus

Pull NVMe fixes from Keith for 4.16-rc.

* 'for-jens' of git://git.infradead.org/nvme:
  nvmet: fix PSDT field check in command format
  nvme-multipath: fix sysfs dangerously created links
  nvme-pci: Fix nvme queue cleanup if IRQ setup fails
  nvmet-loop: use blk_rq_payload_bytes for sgl selection
  nvme-rdma: use blk_rq_payload_bytes instead of blk_rq_bytes
  nvme-fabrics: don't check for non-NULL module in nvmf_register_transport

4 years agonvmet: fix PSDT field check in command format
Max Gurtovoy [Wed, 24 Jan 2018 15:31:45 +0000 (17:31 +0200)]
nvmet: fix PSDT field check in command format

PSDT field section according to NVM_Express-1.3:
"This field specifies whether PRPs or SGLs are used for any data
transfer associated with the command. PRPs shall be used for all
Admin commands for NVMe over PCIe. SGLs shall be used for all Admin
and I/O commands for NVMe over Fabrics. This field shall be set to
01b for NVMe over Fabrics 1.0 implementations.

Suggested-by: Idan Burstein <idanb@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
4 years agonvme-multipath: fix sysfs dangerously created links
Baegjae Sung [Wed, 28 Feb 2018 07:06:04 +0000 (16:06 +0900)]
nvme-multipath: fix sysfs dangerously created links

If multipathing is enabled, each NVMe subsystem creates a head
namespace (e.g., nvme0n1) and multiple private namespaces
(e.g., nvme0c0n1 and nvme0c1n1) in sysfs. When creating links for
private namespaces, links of head namespace are used, so the
namespace creation order must be followed (e.g., nvme0n1 ->
nvme0c1n1). If the order is not followed, links of sysfs will be
incomplete or kernel panic will occur.

The kernel panic was:
  kernel BUG at fs/sysfs/symlink.c:27!
  Call Trace:
    nvme_mpath_add_disk_links+0x5d/0x80 [nvme_core]
    nvme_validate_ns+0x5c2/0x850 [nvme_core]
    nvme_scan_work+0x1af/0x2d0 [nvme_core]

Correct order
Context A     Context B
nvme0n1
nvme0c0n1     nvme0c1n1

Incorrect order
Context A     Context B
              nvme0c1n1
nvme0n1
nvme0c0n1

The nvme_mpath_add_disk (for creating head namespace) is called
just before the nvme_mpath_add_disk_links (for creating private
namespaces). In nvme_mpath_add_disk, the first context acquires
the lock of subsystem and creates a head namespace, and other
contexts do nothing by checking GENHD_FL_UP of a head namespace
after waiting to acquire the lock. We verified the code with or
without multipathing using three vendors of dual-port NVMe SSDs.

Signed-off-by: Baegjae Sung <baegjae@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
4 years agonbd: fix return value in error handling path
Gustavo A. R. Silva [Mon, 12 Feb 2018 17:14:55 +0000 (11:14 -0600)]
nbd: fix return value in error handling path

It seems that the proper value to return in this particular case is the
one contained into variable new_index instead of ret.

Addresses-Coverity-ID: 1465148 ("Copy-paste error")
Fixes: e46c7287b1c2 ("nbd: add a basic netlink interface")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: fix kcrashes with fio in RAID5 backend dev
Tang Junhui [Tue, 27 Feb 2018 17:49:30 +0000 (09:49 -0800)]
bcache: fix kcrashes with fio in RAID5 backend dev

Kernel crashed when run fio in a RAID5 backend bcache device, the call
trace is bellow:
[  440.012034] kernel BUG at block/blk-ioc.c:146!
[  440.012696] invalid opcode: 0000 [#1] SMP NOPTI
[  440.026537] CPU: 2 PID: 2205 Comm: md127_raid5 Not tainted 4.15.0 #8
[  440.027441] Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 07/16
/2015
[  440.028615] RIP: 0010:put_io_context+0x8b/0x90
[  440.029246] RSP: 0018:ffffa8c882b43af8 EFLAGS: 00010246
[  440.029990] RAX: 0000000000000000 RBX: ffffa8c88294fca0 RCX: 0000000000
0f4240
[  440.031006] RDX: 0000000000000004 RSI: 0000000000000286 RDI: ffffa8c882
94fca0
[  440.032030] RBP: ffffa8c882b43b10 R08: 0000000000000003 R09: ffff949cb8
0c1700
[  440.033206] R10: 0000000000000104 R11: 000000000000b71c R12: 00000000000
01000
[  440.034222] R13: 0000000000000000 R14: ffff949cad84db70 R15: ffff949cb11
bd1e0
[  440.035239] FS:  0000000000000000(0000) GS:ffff949cba280000(0000) knlGS:
0000000000000000
[  440.060190] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  440.084967] CR2: 00007ff0493ef000 CR3: 00000002f1e0a002 CR4: 00000000001
606e0
[  440.110498] Call Trace:
[  440.135443]  bio_disassociate_task+0x1b/0x60
[  440.160355]  bio_free+0x1b/0x60
[  440.184666]  bio_put+0x23/0x30
[  440.208272]  search_free+0x23/0x40 [bcache]
[  440.231448]  cached_dev_write_complete+0x31/0x70 [bcache]
[  440.254468]  closure_put+0xb6/0xd0 [bcache]
[  440.277087]  request_endio+0x30/0x40 [bcache]
[  440.298703]  bio_endio+0xa1/0x120
[  440.319644]  handle_stripe+0x418/0x2270 [raid456]
[  440.340614]  ? load_balance+0x17b/0x9c0
[  440.360506]  handle_active_stripes.isra.58+0x387/0x5a0 [raid456]
[  440.380675]  ? __release_stripe+0x15/0x20 [raid456]
[  440.400132]  raid5d+0x3ed/0x5d0 [raid456]
[  440.419193]  ? schedule+0x36/0x80
[  440.437932]  ? schedule_timeout+0x1d2/0x2f0
[  440.456136]  md_thread+0x122/0x150
[  440.473687]  ? wait_woken+0x80/0x80
[  440.491411]  kthread+0x102/0x140
[  440.508636]  ? find_pers+0x70/0x70
[  440.524927]  ? kthread_associate_blkcg+0xa0/0xa0
[  440.541791]  ret_from_fork+0x35/0x40
[  440.558020] Code: c2 48 00 5b 41 5c 41 5d 5d c3 48 89 c6 4c 89 e7 e8 bb c2
48 00 48 8b 3d bc 36 4b 01 48 89 de e8 7c f7 e0 ff 5b 41 5c 41 5d 5d c3 <0f> 0b
0f 1f 00 0f 1f 44 00 00 55 48 8d 47 b8 48 89 e5 41 57 41
[  440.610020] RIP: put_io_context+0x8b/0x90 RSP: ffffa8c882b43af8
[  440.628575] ---[ end trace a1fd79d85643a73e ]--

All the crash issue happened when a bypass IO coming, in such scenario
s->iop.bio is pointed to the s->orig_bio. In search_free(), it finishes the
s->orig_bio by calling bio_complete(), and after that, s->iop.bio became
invalid, then kernel would crash when calling bio_put(). Maybe its upper
layer's faulty, since bio should not be freed before we calling bio_put(),
but we'd better calling bio_put() first before calling bio_complete() to
notify upper layer ending this bio.

This patch moves bio_complete() under bio_put() to avoid kernel crash.

[mlyle: fixed commit subject for character limits]

Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Tested-by: Matthias Ferdinand <bcache@mfedv.net>
Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: correct flash only vols (check all uuids)
Coly Li [Tue, 27 Feb 2018 17:49:29 +0000 (09:49 -0800)]
bcache: correct flash only vols (check all uuids)

Commit 2831231d4c3f ("bcache: reduce cache_set devices iteration by
devices_max_used") adds c->devices_max_used to reduce iteration of
c->uuids elements, this value is updated in bcache_device_attach().

But for flash only volume, when calling flash_devs_run(), the function
bcache_device_attach() is not called yet and c->devices_max_used is not
updated. The unexpected result is, the flash only volume won't be run
by flash_devs_run().

This patch fixes the issue by iterate all c->uuids elements in
flash_devs_run(). c->devices_max_used will be updated properly when
bcache_device_attach() gets called.

[mlyle: commit subject edited for character limit]

Fixes: 2831231d4c3f ("bcache: reduce cache_set devices iteration by devices_max_used")
Reported-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblktrace_api.h: fix comment for struct blk_user_trace_setup
Eric Biggers [Sat, 27 Jan 2018 00:58:06 +0000 (16:58 -0800)]
blktrace_api.h: fix comment for struct blk_user_trace_setup

'struct blk_user_trace_setup' is passed to BLKTRACESETUP, not
BLKTRACESTART.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblockdev: Avoid two active bdev inodes for one device
Jan Kara [Mon, 26 Feb 2018 12:01:42 +0000 (13:01 +0100)]
blockdev: Avoid two active bdev inodes for one device

When blkdev_open() races with device removal and creation it can happen
that unhashed bdev inode gets associated with newly created gendisk
like:

CPU0 CPU1
blkdev_open()
  bdev = bd_acquire()
del_gendisk()
  bdev_unhash_inode(bdev);
remove device
create new device with the same number
  __blkdev_get()
    disk = get_gendisk()
      - gets reference to gendisk of the new device

Now another blkdev_open() will not find original 'bdev' as it got
unhashed, create a new one and associate it with the same 'disk' at
which point problems start as we have two independent page caches for
one device.

Fix the problem by verifying that the bdev inode didn't get unhashed
before we acquired gendisk reference. That way we make sure gendisk can
get associated only with visible bdev inodes.

Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agogenhd: Fix BUG in blkdev_open()
Jan Kara [Mon, 26 Feb 2018 12:01:41 +0000 (13:01 +0100)]
genhd: Fix BUG in blkdev_open()

When two blkdev_open() calls for a partition race with device removal
and recreation, we can hit BUG_ON(!bd_may_claim(bdev, whole, holder)) in
blkdev_open(). The race can happen as follows:

CPU0 CPU1 CPU2
del_gendisk()
  bdev_unhash_inode(part1);

blkdev_open(part1, O_EXCL) blkdev_open(part1, O_EXCL)
  bdev = bd_acquire()   bdev = bd_acquire()
  blkdev_get(bdev)
    bd_start_claiming(bdev)
      - finds old inode 'whole'
      bd_prepare_to_claim() -> 0
  bdev_unhash_inode(whole);
<device removed>
<new device under same
 number created>
  blkdev_get(bdev);
    bd_start_claiming(bdev)
      - finds new inode 'whole'
      bd_prepare_to_claim()
- this also succeeds as we have
  different 'whole' here...
- bad things happen now as we
  have two exclusive openers of
  the same bdev

The problem here is that block device opens can see various intermediate
states while gendisk is shutting down and then being recreated.

We fix the problem by introducing new lookup_sem in gendisk that
synchronizes gendisk deletion with get_gendisk() and furthermore by
making sure that get_gendisk() does not return gendisk that is being (or
has been) deleted. This makes sure that once we ever manage to look up
newly created bdev inode, we are also guaranteed that following
get_gendisk() will either return failure (and we fail open) or it
returns gendisk for the new device and following bdget_disk() will
return new bdev inode (i.e., blkdev_open() follows the path as if it is
completely run after new device is created).

Reported-and-analyzed-by: Hou Tao <houtao1@huawei.com>
Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agogenhd: Fix use after free in __blkdev_get()
Jan Kara [Mon, 26 Feb 2018 12:01:40 +0000 (13:01 +0100)]
genhd: Fix use after free in __blkdev_get()

When two blkdev_open() calls race with device removal and recreation,
__blkdev_get() can use looked up gendisk after it is freed:

CPU0 CPU1 CPU2
del_gendisk(disk);
  bdev_unhash_inode(inode);
blkdev_open() blkdev_open()
  bdev = bd_acquire(inode);
    - creates and returns new inode
  bdev = bd_acquire(inode);
    - returns the same inode
  __blkdev_get(devt)   __blkdev_get(devt)
    disk = get_gendisk(devt);
      - got structure of device going away
<finish device removal>
<new device gets
 created under the same
 device number>
  disk = get_gendisk(devt);
    - got new device structure
  if (!bdev->bd_openers) {
    does the first open
  }
    if (!bdev->bd_openers)
      - false
    } else {
      put_disk_and_module(disk)
        - remember this was old device - this was last ref and disk is
          now freed
    }
    disk_unblock_events(disk); -> oops

Fix the problem by making sure we drop reference to disk in
__blkdev_get() only after we are really done with it.

Reported-by: Hou Tao <houtao1@huawei.com>
Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agogenhd: Add helper put_disk_and_module()
Jan Kara [Mon, 26 Feb 2018 12:01:39 +0000 (13:01 +0100)]
genhd: Add helper put_disk_and_module()

Add a proper counterpart to get_disk_and_module() -
put_disk_and_module(). Currently it is opencoded in several places.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agogenhd: Rename get_disk() to get_disk_and_module()
Jan Kara [Mon, 26 Feb 2018 12:01:38 +0000 (13:01 +0100)]
genhd: Rename get_disk() to get_disk_and_module()

Rename get_disk() to get_disk_and_module() to make sure what the
function does. It's not a great name but at least it is now clear that
put_disk() is not it's counterpart.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agogenhd: Fix leaked module reference for NVME devices
Jan Kara [Mon, 26 Feb 2018 12:01:37 +0000 (13:01 +0100)]
genhd: Fix leaked module reference for NVME devices

Commit 8ddcd653257c "block: introduce GENHD_FL_HIDDEN" added handling of
hidden devices to get_gendisk() but forgot to drop module reference
which is also acquired by get_disk(). Drop the reference as necessary.

Arguably the function naming here is misleading as put_disk() is *not*
the counterpart of get_disk() but let's fix that in the follow up
commit since that will be more intrusive.

Fixes: 8ddcd653257c18a669fcb75ee42c37054908e0d6
CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agodirect-io: Fix sleep in atomic due to sync AIO
Jan Kara [Mon, 26 Feb 2018 11:51:43 +0000 (12:51 +0100)]
direct-io: Fix sleep in atomic due to sync AIO

Commit e864f39569f4 "fs: add RWF_DSYNC aand RWF_SYNC" added additional
way for direct IO to become synchronous and thus trigger fsync from the
IO completion handler. Then commit 9830f4be159b "fs: Use RWF_* flags for
AIO operations" allowed these flags to be set for AIO as well. However
that commit forgot to update the condition checking whether the IO
completion handling should be defered to a workqueue and thus AIO DIO
with RWF_[D]SYNC set will call fsync() from IRQ context resulting in
sleep in atomic.

Fix the problem by checking directly iocb flags (the same way as it is
done in dio_complete()) instead of checking all conditions that could
lead to IO being synchronous.

CC: Christoph Hellwig <hch@lst.de>
CC: Goldwyn Rodrigues <rgoldwyn@suse.com>
CC: stable@vger.kernel.org
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 9830f4be159b29399d107bffb99e0132bc5aedd4
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonvme-pci: Fix nvme queue cleanup if IRQ setup fails
Jianchao Wang [Thu, 15 Feb 2018 11:13:41 +0000 (19:13 +0800)]
nvme-pci: Fix nvme queue cleanup if IRQ setup fails

This patch fixes nvme queue cleanup if requesting an IRQ handler for
the queue's vector fails. It does this by resetting the cq_vector to
the uninitialized value of -1 so it is ignored for a controller reset.

Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
[changelog updates, removed misc whitespace changes]
Signed-off-by: Keith Busch <keith.busch@intel.com>
4 years agoblock: kyber: fix domain token leak during requeue
Ming Lei [Fri, 23 Feb 2018 15:36:57 +0000 (23:36 +0800)]
block: kyber: fix domain token leak during requeue

When requeuing request, the domain token should have been freed
before re-inserting the request to io scheduler. Otherwise, the
assigned domain token will be leaked, and IO hang can be caused.

Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch
Ming Lei [Fri, 23 Feb 2018 15:36:56 +0000 (23:36 +0800)]
blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch

__blk_mq_requeue_request() covers two cases:

- one is that the requeued request is added to hctx->dispatch, such as
blk_mq_dispatch_rq_list()

- another case is that the request is requeued to io scheduler, such as
blk_mq_requeue_request().

We should call io sched's .requeue_request callback only for the 2nd
case.

Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Omar Sandoval <osandov@fb.com>
Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: pass inclusive 'lend' parameter to truncate_inode_pages_range
Ming Lei [Sat, 10 Feb 2018 00:46:17 +0000 (08:46 +0800)]
block: pass inclusive 'lend' parameter to truncate_inode_pages_range

The 'lend' parameter of truncate_inode_pages_range is required to be
inclusive, so follow the rule.

This patch fixes one memory corruption triggered by discard.

Cc: <stable@vger.kernel.org>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
Fixes: 351499a172c0 ("block: Invalidate cache on discard v2")
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoMIPS: boot: Define __ASSEMBLY__ for its.S build
Kees Cook [Fri, 23 Feb 2018 00:59:26 +0000 (16:59 -0800)]
MIPS: boot: Define __ASSEMBLY__ for its.S build

The MIPS %.its.S compiler command did not define __ASSEMBLY__, which meant
when compiler_types.h was added to kconfig.h, unexpected things appeared
(e.g. struct declarations) which should not have been present. As done in
the general %.S compiler command, __ASSEMBLY__ is now included here too.

The failure was:

    Error: arch/mips/boot/vmlinux.gz.its:201.1-2 syntax error
    FATAL ERROR: Unable to parse input tree
    /usr/bin/mkimage: Can't read arch/mips/boot/vmlinux.gz.itb.tmp: Invalid argument
    /usr/bin/mkimage Can't add hashes to FIT blob

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 28128c61e08e ("kconfig.h: Include compiler types to avoid missed struct attributes")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoMerge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebieder...
Linus Torvalds [Fri, 23 Feb 2018 01:04:06 +0000 (17:04 -0800)]
Merge branch 'siginfo-linus' of git://git./linux/kernel/git/ebiederm/user-namespace

Pull siginfo fix from Eric Biederman:
 "This fixes a build error that only shows up on blackfin"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  fs/signalfd: fix build error for BUS_MCEERR_AR

4 years agoMerge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Linus Torvalds [Fri, 23 Feb 2018 00:38:10 +0000 (16:38 -0800)]
Merge branch 'linus' of git://git./linux/kernel/git/herbert/crypto-2.6

Pull crypto fix from Herbert Xu:
 "Fix an oops in the s5p-sss driver when used with ecb(aes)"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: s5p-sss - Fix kernel Oops in AES-ECB mode

4 years agofs/signalfd: fix build error for BUS_MCEERR_AR
Randy Dunlap [Mon, 12 Feb 2018 21:18:38 +0000 (13:18 -0800)]
fs/signalfd: fix build error for BUS_MCEERR_AR

Fix build error in fs/signalfd.c by using same method that is used in
kernel/signal.c: separate blocks for different signal si_code values.

./fs/signalfd.c: error: 'BUS_MCEERR_AR' undeclared (first use in this function)

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
4 years agoMerge tag 'usb-4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Linus Torvalds [Thu, 22 Feb 2018 20:13:01 +0000 (12:13 -0800)]
Merge tag 'usb-4.16-rc3' of git://git./linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are a number of USB fixes for 4.16-rc3

  Nothing major, but a number of different fixes all over the place in
  the USB stack for reported issues. Mostly gadget driver fixes,
  although the typical set of xhci bugfixes are there, along with some
  new quirks additions as well.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (39 commits)
  Revert "usb: musb: host: don't start next rx urb if current one failed"
  usb: musb: fix enumeration after resume
  usb: cdc_acm: prevent race at write to acm while system resumes
  Add delay-init quirk for Corsair K70 RGB keyboards
  usb: ohci: Proper handling of ed_rm_list to handle race condition between usb_kill_urb() and finish_unlinks()
  usb: host: ehci: always enable interrupt for qtd completion at test mode
  usb: ldusb: add PIDs for new CASSY devices supported by this driver
  usb: renesas_usbhs: missed the "running" flag in usb_dmac with rx path
  usb: host: ehci: use correct device pointer for dma ops
  usbip: keep usbip_device sockfd state in sync with tcp_socket
  ohci-hcd: Fix race condition caused by ohci_urb_enqueue() and io_watchdog_func()
  USB: serial: option: Add support for Quectel EP06
  xhci: fix xhci debugfs errors in xhci_stop
  xhci: xhci debugfs device nodes weren't removed after device plugged out
  xhci: Fix xhci debugfs devices node disappearance after hibernation
  xhci: Fix NULL pointer in xhci debugfs
  xhci: Don't print a warning when setting link state for disabled ports
  xhci: workaround for AMD Promontory disabled ports wakeup
  usb: dwc3: core: Fix ULPI PHYs and prevent phy_get/ulpi_init during suspend/resume
  USB: gadget: udc: Add missing platform_device_put() on error in bdc_pci_probe()
  ...

4 years agoMerge tag 'staging-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
Linus Torvalds [Thu, 22 Feb 2018 20:05:43 +0000 (12:05 -0800)]
Merge tag 'staging-4.16-rc2' of git://git./linux/kernel/git/gregkh/staging

Pull staging/IIO fixes from Greg KH:
 "Here are a small number of staging and iio driver fixes for 4.16-rc2.

  The IIO fixes are all for reported things, and the android driver
  fixes also resolve some reported problems. The remaining fsl-mc
  Kconfig change resolves a build testing error that Arnd reported.

  All of these have been in linux-next with no reported issues"

* tag 'staging-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: buffer: check if a buffer has been set up when poll is called
  iio: adis_lib: Initialize trigger before requesting interrupt
  staging: android: ion: Zero CMA allocated memory
  staging: android: ashmem: Fix a race condition in pin ioctls
  staging: fsl-mc: fix build testing on x86
  iio: srf08: fix link error "devm_iio_triggered_buffer_setup" undefined
  staging: iio: ad5933: switch buffer mode to software
  iio: adc: stm32: fix stm32h7_adc_enable error handling
  staging: iio: adc: ad7192: fix external frequency setting
  iio: adc: aspeed: Fix error handling path

4 years agoMerge tag 'char-misc-4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...
Linus Torvalds [Thu, 22 Feb 2018 20:04:05 +0000 (12:04 -0800)]
Merge tag 'char-misc-4.16-rc3' of git://git./linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
 "Here are a handful of char/misc driver fixes for 4.16-rc3.

  There are some binder driver fixes to resolve reported issues in
  stress testing the recent binder changes, some extcon driver fixes,
  and a few mei driver fixes and new device ids.

  All of these, with the exception of the mei driver id additions, have
  been in linux-next for a while. I forgot to push out the mei driver id
  additions to kernel.org until today, but all build tests pass with
  them enabled"

* tag 'char-misc-4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mei: me: add cannon point device ids for 4th device
  mei: me: add cannon point device ids
  mei: set device client to the disconnected state upon suspend.
  ANDROID: binder: synchronize_rcu() when using POLLFREE.
  binder: replace "%p" with "%pK"
  ANDROID: binder: remove WARN() for redundant txn error
  binder: check for binder_thread allocation failure in binder_poll()
  extcon: int3496: process id-pin first so that we start with the right status
  Revert "extcon: axp288: Redo charger type detection a couple of seconds after probe()"
  extcon: axp288: Constify the axp288_pwr_up_down_info array

4 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Linus Torvalds [Thu, 22 Feb 2018 19:57:39 +0000 (11:57 -0800)]
Merge tag 'for-linus' of git://git./linux/kernel/git/rdma/rdma

Pull rdma fixes from Doug Ledford:
 "Nothing in this is overly interesting, it's mostly your garden variety
  fixes.

  There was some work in this merge cycle around the new ioctl kABI, so
  there are fixes in here related to that (probably with more to come).

  We've also recently added new netlink support with a goal of moving
  the primary means of configuring the entire subsystem to netlink
  (eventually, this is a long term project), so there are fixes for
  that.

  Then a few bnxt_re driver fixes, and a few minor WARN_ON removals, and
  that covers this pull request. There are already a few more fixes on
  the list as of this morning, so there will certainly be more to come
  in this rc cycle ;-)

  Summary:

   - Lots of fixes for the new IOCTL interface and general uverbs flow.
     Found through testing and syzkaller

   - Bugfixes for the new resource track netlink reporting

   - Remove some unneeded WARN_ONs that were triggering for some users
     in IPoIB

   - Various fixes for the bnxt_re driver"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (27 commits)
  RDMA/uverbs: Fix kernel panic while using XRC_TGT QP type
  RDMA/bnxt_re: Avoid system hang during device un-reg
  RDMA/bnxt_re: Fix system crash during load/unload
  RDMA/bnxt_re: Synchronize destroy_qp with poll_cq
  RDMA/bnxt_re: Unpin SQ and RQ memory if QP create fails
  RDMA/bnxt_re: Disable atomic capability on bnxt_re adapters
  RDMA/restrack: don't use uaccess_kernel()
  RDMA/verbs: Check existence of function prior to accessing it
  RDMA/vmw_pvrdma: Fix usage of user response structures in ABI file
  RDMA/uverbs: Sanitize user entered port numbers prior to access it
  RDMA/uverbs: Fix circular locking dependency
  RDMA/uverbs: Fix bad unlock balance in ib_uverbs_close_xrcd
  RDMA/restrack: Increment CQ restrack object before committing
  RDMA/uverbs: Protect from command mask overflow
  IB/uverbs: Fix unbalanced unlock on error path for rdma_explicit_destroy
  IB/uverbs: Improve lockdep_check
  RDMA/uverbs: Protect from races between lookup and destroy of uobjects
  IB/uverbs: Hold the uobj write lock after allocate
  IB/uverbs: Fix possible oops with duplicate ioctl attributes
  IB/uverbs: Add ioctl support for 32bit processes
  ...

4 years agoMerge tag 'riscv-for-linus-4.16-rc3-riscv_cleanups' of git://git.kernel.org/pub/scm...
Linus Torvalds [Thu, 22 Feb 2018 19:53:17 +0000 (11:53 -0800)]
Merge tag 'riscv-for-linus-4.16-rc3-riscv_cleanups' of git://git./linux/kernel/git/palmer/riscv-linux

Pull RISC-V cleanups from Palmer Dabbelt:
 "This contains a handful of small cleanups.

  The only functional change is that IRQs are now enabled during
  exception handling, which was found when some warnings triggered with
  `CONFIG_DEBUG_ATOMIC_SLEEP=y`.

  The remaining fixes should have no functional change: `sbi_save()` has
  been renamed to `parse_dtb()` reflect what it actually does, and a
  handful of unused Kconfig entries have been removed"

* tag 'riscv-for-linus-4.16-rc3-riscv_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  Rename sbi_save to parse_dtb to improve code readability
  RISC-V: Enable IRQ during exception handling
  riscv: Remove ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select
  riscv: kconfig: Remove RISCV_IRQ_INTC select
  riscv: Remove ARCH_WANT_OPTIONAL_GPIOLIB select

4 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Thu, 22 Feb 2018 18:45:46 +0000 (10:45 -0800)]
Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: don't defer struct page initialization for Xen pv guests
  lib/Kconfig.debug: enable RUNTIME_TESTING_MENU
  vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
  selftests/memfd: add run_fuse_test.sh to TEST_FILES
  bug.h: work around GCC PR82365 in BUG()
  mm/swap.c: make functions and their kernel-doc agree (again)
  mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc
  ida: do zeroing in ida_pre_get()
  mm, swap, frontswap: fix THP swap if frontswap enabled
  certs/blacklist_nohashes.c: fix const confusion in certs blacklist
  kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
  mm, mlock, vmscan: no more skipping pagevecs
  mm: memcontrol: fix NR_WRITEBACK leak in memcg and system stats
  Kbuild: always define endianess in kconfig.h
  include/linux/sched/mm.h: re-inline mmdrop()
  tools: fix cross-compile var clobbering

4 years agoefivarfs: Limit the rate for non-root to read files
Luck, Tony [Thu, 22 Feb 2018 17:15:06 +0000 (09:15 -0800)]
efivarfs: Limit the rate for non-root to read files

Each read from a file in efivarfs results in two calls to EFI
(one to get the file size, another to get the actual data).

On X86 these EFI calls result in broadcast system management
interrupts (SMI) which affect performance of the whole system.
A malicious user can loop performing reads from efivarfs bringing
the system to its knees.

Linus suggested per-user rate limit to solve this.

So we add a ratelimit structure to "user_struct" and initialize
it for the root user for no limit. When allocating user_struct for
other users we set the limit to 100 per second. This could be used
for other places that want to limit the rate of some detrimental
user action.

In efivarfs if the limit is exceeded when reading, we take an
interruptible nap for 50ms and check the rate limit again.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokconfig.h: Include compiler types to avoid missed struct attributes
Kees Cook [Thu, 22 Feb 2018 17:41:40 +0000 (09:41 -0800)]
kconfig.h: Include compiler types to avoid missed struct attributes

The header files for some structures could get included in such a way
that struct attributes (specifically __randomize_layout from path.h) would
be parsed as variable names instead of attributes. This could lead to
some instances of a structure being unrandomized, causing nasty GPFs, etc.

This patch makes sure the compiler_types.h header is included in
kconfig.h so that we've always got types and struct attributes defined,
since kconfig.h is included from the compiler command line.

Reported-by: Patrick McLean <chutzpah@gentoo.org>
Root-caused-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Fixes: 3859a271a003 ("randstruct: Mark various structs for randomization")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agox86: Treat R_X86_64_PLT32 as R_X86_64_PC32
H.J. Lu [Wed, 7 Feb 2018 22:20:09 +0000 (14:20 -0800)]
x86: Treat R_X86_64_PLT32 as R_X86_64_PC32

On i386, there are 2 types of PLTs, PIC and non-PIC.  PIE and shared
objects must use PIC PLT.  To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first.  There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.

On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches.  Linker can always reduce
PLT32 relocation to PC32 if function is defined locally.   Local
functions should use PC32 relocation.  As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.

R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.

[ hjl is working on having better documentation on this all, but a few
  more notes from him:

   "PLT32 relocation is used as marker for PC-relative branches. Because
    of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
    doesn't have GOT.

    As for symbol resolution, PLT32 and PC32 relocations are almost
    interchangeable. But when linker sees PLT32 relocation against a
    protected symbol, it can resolved locally at link-time since it is
    used on a branch instruction. Linker can't do that for PC32
    relocation"

  but for the kernel use, the two are basically the same, and this
  commit gets things building and working with the current binutils
  master   - Linus ]

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agonvmet-loop: use blk_rq_payload_bytes for sgl selection
Christoph Hellwig [Thu, 22 Feb 2018 15:24:10 +0000 (07:24 -0800)]
nvmet-loop: use blk_rq_payload_bytes for sgl selection

blk_rq_bytes does the wrong thing for special payloads like discards and
might cause the driver to not set up a SGL.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
4 years agonvme-rdma: use blk_rq_payload_bytes instead of blk_rq_bytes
Christoph Hellwig [Thu, 22 Feb 2018 15:24:09 +0000 (07:24 -0800)]
nvme-rdma: use blk_rq_payload_bytes instead of blk_rq_bytes

blk_rq_bytes does the wrong thing for special payloads like discards and
might cause the driver to not set up a SGL.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
4 years agonvme-fabrics: don't check for non-NULL module in nvmf_register_transport
Christoph Hellwig [Thu, 22 Feb 2018 15:24:08 +0000 (07:24 -0800)]
nvme-fabrics: don't check for non-NULL module in nvmf_register_transport

THIS_MODULE evaluates to NULL when used from code built into the kernel,
thus breaking built-in transport modules.  Remove the bogus check.

Fixes: 0de5cd36 ("nvme-fabrics: protect against module unload during create_ctrl")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
4 years agomm: don't defer struct page initialization for Xen pv guests
Juergen Gross [Wed, 21 Feb 2018 22:46:09 +0000 (14:46 -0800)]
mm: don't defer struct page initialization for Xen pv guests

Commit f7f99100d8d9 ("mm: stop zeroing memory during allocation in
vmemmap") broke Xen pv domains in some configurations, as the "Pinned"
information in struct page of early page tables could get lost.

This will lead to the kernel trying to write directly into the page
tables instead of asking the hypervisor to do so.  The result is a crash
like the following:

  BUG: unable to handle kernel paging request at ffff8801ead19008
  IP: xen_set_pud+0x4e/0xd0
  PGD 1c0a067 P4D 1c0a067 PUD 23a0067 PMD 1e9de0067 PTE 80100001ead19065
  Oops: 0003 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-default+ #271
  Hardware name: Dell Inc. Latitude E6440/0159N7, BIOS A07 06/26/2014
  task: ffffffff81c10480 task.stack: ffffffff81c00000
  RIP: e030:xen_set_pud+0x4e/0xd0
  Call Trace:
   __pmd_alloc+0x128/0x140
   ioremap_page_range+0x3f4/0x410
   __ioremap_caller+0x1c3/0x2e0
   acpi_os_map_iomem+0x175/0x1b0
   acpi_tb_acquire_table+0x39/0x66
   acpi_tb_validate_table+0x44/0x7c
   acpi_tb_verify_temp_table+0x45/0x304
   acpi_reallocate_root_table+0x12d/0x141
   acpi_early_init+0x4d/0x10a
   start_kernel+0x3eb/0x4a1
   xen_start_kernel+0x528/0x532
  Code: 48 01 e8 48 0f 42 15 a2 fd be 00 48 01 d0 48 ba 00 00 00 00 00 ea ff ff 48 c1 e8 0c 48 c1 e0 06 48 01 d0 48 8b 00 f6 c4 02 75 5d <4c> 89 65 00 5b 5d 41 5c c3 65 8b 05 52 9f fe 7e 89 c0 48 0f a3
  RIP: xen_set_pud+0x4e/0xd0 RSP: ffffffff81c03cd8
  CR2: ffff8801ead19008
  ---[ end trace 38eca2e56f1b642e ]---

Avoid this problem by not deferring struct page initialization when
running as Xen pv guest.

Pavel said:

: This is unique for Xen, so this particular issue won't effect other
: configurations.  I am going to investigate if there is a way to
: re-enable deferred page initialization on xen guests.

[akpm@linux-foundation.org: explicitly include xen.h]
Link: http://lkml.kernel.org/r/20180216154101.22865-1-jgross@suse.com
Fixes: f7f99100d8d95d ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: <stable@vger.kernel.org> [4.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agolib/Kconfig.debug: enable RUNTIME_TESTING_MENU
Anders Roxell [Wed, 21 Feb 2018 22:46:05 +0000 (14:46 -0800)]
lib/Kconfig.debug: enable RUNTIME_TESTING_MENU

Commit d3deafaa8b5c ("lib/: make RUNTIME_TESTS a menuconfig to ease
disabling it all") causes a regression when using runtime tests due to
it defaults RUNTIME_TESTING_MENU to not set.

Link: http://lkml.kernel.org/r/20180214133015.10090-1-anders.roxell@linaro.org
Fixes: d3deafaa8b5c ("lib/: make RUNTIME_TESTS a menuconfig to easedisabling it all")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Cc: Vincent Legoll <vincent.legoll@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agovmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
Michal Hocko [Wed, 21 Feb 2018 22:46:01 +0000 (14:46 -0800)]
vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems

Kai Heng Feng has noticed that BUG_ON(PageHighMem(pg)) triggers in
drivers/media/common/saa7146/saa7146_core.c since 19809c2da28a ("mm,
vmalloc: use __GFP_HIGHMEM implicitly").

saa7146_vmalloc_build_pgtable uses vmalloc_32 and it is reasonable to
expect that the resulting page is not in highmem.  The above commit
aimed to add __GFP_HIGHMEM only for those requests which do not specify
any zone modifier gfp flag.  vmalloc_32 relies on GFP_VMALLOC32 which
should do the right thing.  Except it has been missed that GFP_VMALLOC32
is an alias for GFP_KERNEL on 32b architectures.  Thanks to Matthew to
notice this.

Fix the problem by unconditionally setting GFP_DMA32 in GFP_VMALLOC32
for !64b arches (as a bailout).  This should do the right thing and use
ZONE_NORMAL which should be always below 4G on 32b systems.

Debugged by Matthew Wilcox.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20180212095019.GX21609@dhcp22.suse.cz
Fixes: 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitly”)
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Kai Heng Feng <kai.heng.feng@canonical.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoselftests/memfd: add run_fuse_test.sh to TEST_FILES
Anders Roxell [Wed, 21 Feb 2018 22:45:58 +0000 (14:45 -0800)]
selftests/memfd: add run_fuse_test.sh to TEST_FILES

While testing memfd tests, there is a missing script, as reported by
kselftest:

  ./run_tests.sh: line 7: ./run_fuse_test.sh: No such file or directory

Link: http://lkml.kernel.org/r/1517955779-11386-1-git-send-email-daniel.diaz@linaro.org
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Daniel Díaz <daniel.diaz@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agobug.h: work around GCC PR82365 in BUG()
Arnd Bergmann [Wed, 21 Feb 2018 22:45:54 +0000 (14:45 -0800)]
bug.h: work around GCC PR82365 in BUG()

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc]
Tested-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc]
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agomm/swap.c: make functions and their kernel-doc agree (again)
Mike Rapoport [Wed, 21 Feb 2018 22:45:50 +0000 (14:45 -0800)]
mm/swap.c: make functions and their kernel-doc agree (again)

There was a conflict between the commit e02a9f048ef7 ("mm/swap.c: make
functions and their kernel-doc agree") and the commit f144c390f905 ("mm:
docs: fix parameter names mismatch") that both tried to fix mismatch
betweeen pagevec_lookup_entries() parameter names and their description.

Since nr_entries is a better name for the parameter, fix the description
again.

Link: http://lkml.kernel.org/r/1518116946-20947-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agomm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc
Mike Rapoport [Wed, 21 Feb 2018 22:45:46 +0000 (14:45 -0800)]
mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc

[akpm@linux-foundation.org: add colon, per Randy]
Link: http://lkml.kernel.org/r/1518116984-21141-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agoida: do zeroing in ida_pre_get()
Rasmus Villemoes [Wed, 21 Feb 2018 22:45:43 +0000 (14:45 -0800)]
ida: do zeroing in ida_pre_get()

As far as I can tell, the only place the per-cpu ida_bitmap is populated
is in ida_pre_get.  The pre-allocated element is stolen in two places in
ida_get_new_above, in both cases immediately followed by a memset(0).

Since ida_get_new_above is called with locks held, do the zeroing in
ida_pre_get, or rather let kmalloc() do it.  Also, apparently gcc
generates ~44 bytes of code to do a memset(, 0, 128):

  $ scripts/bloat-o-meter vmlinux.{0,1}
  add/remove: 0/0 grow/shrink: 2/1 up/down: 5/-88 (-83)
  Function                                     old     new   delta
  ida_pre_get                                  115     119      +4
  vermagic                                      27      28      +1
  ida_get_new_above                            715     627     -88

Link: http://lkml.kernel.org/r/20180108225634.15340-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agomm, swap, frontswap: fix THP swap if frontswap enabled
Huang Ying [Wed, 21 Feb 2018 22:45:39 +0000 (14:45 -0800)]
mm, swap, frontswap: fix THP swap if frontswap enabled

It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur in
random user space applications as follow,

kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
 #0  0x00007fc08889ae0d _int_malloc (libc.so.6)
 #1  0x00007fc08889c2f3 malloc (libc.so.6)
 #2  0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
 #3  0x0000560e6005e75c n/a (urxvt)
 #4  0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
 #5  0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
 #6  0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
 #7  0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
 #8  0x0000560e6005cb55 ev_run (urxvt)
 #9  0x0000560e6003b9b9 main (urxvt)
 #10 0x00007fc08883af4a __libc_start_main (libc.so.6)
 #11 0x0000560e6003f9da _start (urxvt)

After bisection, it was found the first bad commit is bd4c82c22c36 ("mm,
THP, swap: delay splitting THP after swapped out").

The root cause is as follows:

When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance.  But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved.  After swapping in, tail pages
will not be restored to their original contents, causing memory
corruption in the applications.

This is fixed by refusing to save page in the frontswap store functions
if the page is a THP.  So that the THP will be swapped out to swap
device.

Another choice is to split THP if frontswap is enabled.  But it is found
that the frontswap enabling isn't flexible.  For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.

Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.

Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com
Fixes: bd4c82c22c367e068 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org> [put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Shaohua Li <shli@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org> [4.14]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agocerts/blacklist_nohashes.c: fix const confusion in certs blacklist
Andi Kleen [Wed, 21 Feb 2018 22:45:35 +0000 (14:45 -0800)]
certs/blacklist_nohashes.c: fix const confusion in certs blacklist

const must be marked __initconst, not __initdata.

Link: http://lkml.kernel.org/r/20171222001335.1987-1-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agokernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
David Rientjes [Wed, 21 Feb 2018 22:45:32 +0000 (14:45 -0800)]
kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE

chan->n_subbufs is set by the user and relay_create_buf() does a kmalloc()
of chan->n_subbufs * sizeof(size_t *).

kmalloc_slab() will generate a warning when this fails if
chan->subbufs * sizeof(size_t *) > KMALLOC_MAX_SIZE.

Limit chan->n_subbufs to the maximum allowed kmalloc() size.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802061216100.122576@chino.kir.corp.google.com
Fixes: f6302f1bcd75 ("relay: prevent integer overflow in relay_open()")
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agomm, mlock, vmscan: no more skipping pagevecs
Shakeel Butt [Wed, 21 Feb 2018 22:45:28 +0000 (14:45 -0800)]
mm, mlock, vmscan: no more skipping pagevecs

When a thread mlocks an address space backed either by file pages which
are currently not present in memory or swapped out anon pages (not in
swapcache), a new page is allocated and added to the local pagevec
(lru_add_pvec), I/O is triggered and the thread then sleeps on the page.
On I/O completion, the thread can wake on a different CPU, the mlock
syscall will then sets the PageMlocked() bit of the page but will not be
able to put that page in unevictable LRU as the page is on the pagevec
of a different CPU.  Even on drain, that page will go to evictable LRU
because the PageMlocked() bit is not checked on pagevec drain.

The page will eventually go to right LRU on reclaim but the LRU stats
will remain skewed for a long time.

This patch puts all the pages, even unevictable, to the pagevecs and on
the drain, the pages will be added on their LRUs correctly by checking
their evictability.  This resolves the mlocked pages on pagevec of other
CPUs issue because when those pagevecs will be drained, the mlocked file
pages will go to unevictable LRU.  Also this makes the race with munlock
easier to resolve because the pagevec drains happen in LRU lock.

However there is still one place which makes a page evictable and does
PageLRU check on that page without LRU lock and needs special attention.
TestClearPageMlocked() and isolate_lru_page() in clear_page_mlock().

#0: __pagevec_lru_add_fn #1: clear_page_mlock

SetPageLRU() if (!TestClearPageMlocked())
  return
smp_mb() // <--required
// inside does PageLRU
if (!PageMlocked()) if (isolate_lru_page())
  move to evictable LRU   putback_lru_page()
else
  move to unevictable LRU

In '#1', TestClearPageMlocked() provides full memory barrier semantics
and thus the PageLRU check (inside isolate_lru_page) can not be
reordered before it.

In '#0', without explicit memory barrier, the PageMlocked() check can be
reordered before SetPageLRU().  If that happens, '#0' can put a page in
unevictable LRU and '#1' might have just cleared the Mlocked bit of that
page but fails to isolate as PageLRU fails as '#0' still hasn't set
PageLRU bit of that page.  That page will be stranded on the unevictable
LRU.

There is one (good) side effect though.  Without this patch, the pages
allocated for System V shared memory segment are added to evictable LRUs
even after shmctl(SHM_LOCK) on that segment.  This patch will correctly
put such pages to unevictable LRU.

Link: http://lkml.kernel.org/r/20171121211241.18877-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4 years agomm: memcontrol: fix NR_WRITEBACK leak in memcg and system stats
Johannes Weiner [Wed, 21 Feb 2018 22:45:24 +0000 (14:45 -0800)]
mm: memcontrol: fix NR_WRITEBACK leak in memcg and system stats

After commit a983b5ebee57 ("mm: memcontrol: fix excessive complexity in
memory.stat reporting"), we observed slowly upward creeping NR_WRITEBACK
counts over the course of several days, both the per-memcg stats as well
as the system counter in e.g.  /proc/meminfo.

The conversion from full per-cpu stat counts to per-cpu cached atomic
stat counts introduced an irq-unsafe RMW operation into the updates.

Most stat updates come from process context, but one notable exception
is the NR_WRITEBACK counter.  While writebacks are issued from process
context, they are retired from (soft)irq context.

When writeback completions interrupt the RMW counter updates of new
writebacks being issued, the decs from the completions are lost.

Since the global updates are routed through the joint lruvec API, both
the memcg counters as well as the system counters are affected.

This patch makes the joint stat and event API irq safe.

Link: http://lkml.kernel.org/r/20180203082353.17284-1-hannes@cmpxchg.org
Fixes: a983b5ebee57 ("mm: memcontrol: fix excessive complexity in memory.stat reporting")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Debugged-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>