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>
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>
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>
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: 0983b7ab3db2 ("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>
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>
Bart Van Assche [Fri, 16 Mar 2018 17:31:11 +0000 (10:31 -0700)]
blk-mq-debugfs: Show more request state information
Since commit 51b5ed1dcdf2 ("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.
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:
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 315572f0f6b1 ("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.
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>
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>
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>
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 6f1d7ad6c8e1 ("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 a35c10ce2415 ("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>
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 afe2d8aefa24 ("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 0efbbc116b6c ("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>
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>
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.
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.
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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: 49d639ec628a ("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>
(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>
(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>
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>
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>
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.
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.
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.
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>
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>
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
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>
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>
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>
Coly Li [Tue, 27 Feb 2018 17:49:29 +0000 (09:49 -0800)]
bcache: correct flash only vols (check all uuids)
Commit 35b46af072a4 ("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: 35b46af072a4 ("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>
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>
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:
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>
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>
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>
Jan Kara [Mon, 26 Feb 2018 12:01:37 +0000 (13:01 +0100)]
genhd: Fix leaked module reference for NVME devices
Commit 36e4f5153070 "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: 36e4f51530704a6b6559b772badde1a34eaeef3a CC: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Kara [Mon, 26 Feb 2018 11:51:43 +0000 (12:51 +0100)]
direct-io: Fix sleep in atomic due to sync AIO
Commit 27f3873604e4 "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 2a2d7bcc1d67 "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: 2a2d7bcc1d670073fbd732202e2e5c6f5b756ff7 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
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>
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: 9bc09c376caa ("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>
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>
Linus Torvalds [Thu, 22 Feb 2018 20:13:01 +0000 (12:13 -0800)]
Merge tag 'usb-4.16-rc3' of git://git.kernel.org/pub/scm/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()
...
Linus Torvalds [Thu, 22 Feb 2018 20:05:43 +0000 (12:05 -0800)]
Merge tag 'staging-4.16-rc2' of git://git.kernel.org/pub/scm/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
Linus Torvalds [Thu, 22 Feb 2018 20:04:05 +0000 (12:04 -0800)]
Merge tag 'char-misc-4.16-rc3' of git://git.kernel.org/pub/scm/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
Linus Torvalds [Thu, 22 Feb 2018 19:57:39 +0000 (11:57 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/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
...
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.kernel.org/pub/scm/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
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
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.
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: e6d8f59cd126 ("randstruct: Mark various structs for randomization") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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: b25c2fff ("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>
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 ebc7c84ba621 ("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:
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: ebc7c84ba62125 ("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>
Anders Roxell [Wed, 21 Feb 2018 22:46:05 +0000 (14:46 -0800)]
lib/Kconfig.debug: enable RUNTIME_TESTING_MENU
Commit f2e7209e87ff ("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: f2e7209e87ff ("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>
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 cbc988b7af6e ("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: cbc988b7af6e ("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>
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>
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 55bab0a936e2 ("mm/swap.c: make
functions and their kernel-doc agree") and the commit 0afbcedeff85 ("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>
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>
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,
After bisection, it was found the first bad commit is 0effd3d7e792 ("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: 0effd3d7e792e9b33 ("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>
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>
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 e44db14ab863 ("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: e44db14ab863 ("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>
Arnd Bergmann [Wed, 21 Feb 2018 22:45:20 +0000 (14:45 -0800)]
Kbuild: always define endianess in kconfig.h
Build testing with LTO found a couple of files that get compiled
differently depending on whether asm/byteorder.h gets included early
enough or not. In particular, include/asm-generic/qrwlock_types.h is
affected by this, but there are probably others as well.
The symptom is a series of LTO link time warnings, including these:
net/netlabel/netlabel_unlabeled.h:223: error: type of 'netlbl_unlhsh_add' does not match original declaration [-Werror=lto-type-mismatch]
int netlbl_unlhsh_add(struct net *net,
net/netlabel/netlabel_unlabeled.c:377: note: 'netlbl_unlhsh_add' was previously declared here
include/net/ipv6.h:360: error: type of 'ipv6_renew_options_kern' does not match original declaration [-Werror=lto-type-mismatch]
ipv6_renew_options_kern(struct sock *sk,
net/ipv6/exthdrs.c:1162: note: 'ipv6_renew_options_kern' was previously declared here
net/core/dev.c:761: note: 'dev_get_by_name_rcu' was previously declared here
struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
net/core/dev.c:761: note: code may be misoptimized unless -fno-strict-aliasing is used
drivers/gpu/drm/i915/i915_drv.h:3377: error: type of 'i915_gem_object_set_to_wc_domain' does not match original declaration [-Werror=lto-type-mismatch]
i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write);
drivers/gpu/drm/i915/i915_gem.c:3639: note: 'i915_gem_object_set_to_wc_domain' was previously declared here
include/linux/debugfs.h:92:9: error: type of 'debugfs_attr_read' does not match original declaration [-Werror=lto-type-mismatch]
ssize_t debugfs_attr_read(struct file *file, char __user *buf,
fs/debugfs/file.c:318: note: 'debugfs_attr_read' was previously declared here
include/linux/rwlock_api_smp.h:30: error: type of '_raw_read_unlock' does not match original declaration [-Werror=lto-type-mismatch]
void __lockfunc _raw_read_unlock(rwlock_t *lock) __releases(lock);
kernel/locking/spinlock.c:246:26: note: '_raw_read_unlock' was previously declared here
include/linux/fs.h:3308:5: error: type of 'simple_attr_open' does not match original declaration [-Werror=lto-type-mismatch]
int simple_attr_open(struct inode *inode, struct file *file,
fs/libfs.c:795: note: 'simple_attr_open' was previously declared here
All of the above are caused by include/asm-generic/qrwlock_types.h
failing to include asm/byteorder.h after commit ec0dc971dc51
("locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'")
in linux-4.15.
Similar bugs may or may not exist in older kernels as well, but there is
no easy way to test those with link-time optimizations, and kernels
before 4.14 are harder to fix because they don't have Babu's patch
series
We had similar issues with CONFIG_ symbols in the past and ended up
always including the configuration headers though linux/kconfig.h. This
works around the issue through that same file, defining either
__BIG_ENDIAN or __LITTLE_ENDIAN depending on CONFIG_CPU_BIG_ENDIAN,
which is now always set on all architectures since commit 9bfa7182365c
("arch: define CPU_BIG_ENDIAN for all fixed big endian archs").
Link: http://lkml.kernel.org/r/20180202154104.1522809-2-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Babu Moger <babu.moger@amd.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Martin Kelly [Wed, 21 Feb 2018 22:45:12 +0000 (14:45 -0800)]
tools: fix cross-compile var clobbering
Currently a number of Makefiles break when used with toolchains that
pass extra flags in CC and other cross-compile related variables (such
as --sysroot).
Thus we get this error when we use a toolchain that puts --sysroot in
the CC var:
~/src/linux/tools$ make iio
[snip]
iio_event_monitor.c:18:10: fatal error: unistd.h: No such file or directory
#include <unistd.h>
^~~~~~~~~~
This occurs because we clobber several env vars related to
cross-compiling with lines like this:
CC = $(CROSS_COMPILE)gcc
Although this will point to a valid cross-compiler, we lose any extra
flags that might exist in the CC variable, which can break toolchains
that rely on them (for example, those that use --sysroot).
Although arm-poky-linux-gnueabi-gcc is a cross-compiler, we've lost the
--sysroot and other flags that enable us to find the right libraries to
link against, so we can't find unistd.h and other libraries and headers.
Normally with the --sysroot flag we would find unistd.h in the sdk
directory in the sysroot:
The perf Makefile adds CC = $(CROSS_COMPILE)gcc if and only if CC is not
already set, and it compiles correctly with the above toolchain.
So, generalize the logic that perf uses in the common Makefile and
remove the manual CC = $(CROSS_COMPILE)gcc lines from each Makefile.
Note that this patch does not fix cross-compile for all the tools (some
have other bugs), but it does fix it for all except usb and acpi, which
still have other unrelated issues.
I tested both with and without the patch on native and cross-build and
there appear to be no regressions.
Link: http://lkml.kernel.org/r/20180107214028.23771-1-martin@martingkelly.com Signed-off-by: Martin Kelly <martin@martingkelly.com> Acked-by: Mark Brown <broonie@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Pali Rohar <pali.rohar@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Robert Moore <robert.moore@intel.com> Cc: Lv Zheng <lv.zheng@intel.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Valentina Manea <valentina.manea.m@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Mario Limonciello <mario.limonciello@dell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Leon Romanovsky [Wed, 21 Feb 2018 08:25:01 +0000 (10:25 +0200)]
RDMA/uverbs: Fix kernel panic while using XRC_TGT QP type
Attempt to modify XRC_TGT QP type from the user space (ibv_xsrq_pingpong
invocation) will trigger the following kernel panic. It is caused by the
fact that such QPs missed uobject initialization.
Palmer Dabbelt [Tue, 20 Feb 2018 18:51:19 +0000 (10:51 -0800)]
RISC-V: kconfig cleanups
These three kconfig cleanups were found by ulfalyzer. They're all
things we were selecting that were undefined, either because they'd been
remove upstream or are part of a future RISC-V submission.
* ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE is obselete.
* RISCV_IRQ_INTC is the old name for our interrupt controller driver,
it'll be changed for the final submission and doesn't exist now.
* ARCH_WANT_OPTIONAL_GPIOLIB is obselete.
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