So far there was the possibility that we called
genlmsg_new(GFP_NOIO)/mutex_lock() while holding an rcu_read_lock().
This included cases like:
drbd_sync_handshake (acquire the RCU lock)
drbd_asb_recover_1p
drbd_khelper
drbd_bcast_event
genlmsg_new(GFP_NOIO) --> may sleep
drbd_sync_handshake (acquire the RCU lock)
drbd_asb_recover_1p
drbd_khelper
notify_helper
genlmsg_new(GFP_NOIO) --> may sleep
drbd_sync_handshake (acquire the RCU lock)
drbd_asb_recover_1p
drbd_khelper
notify_helper
mutex_lock --> may sleep
While using GFP_ATOMIC whould have been possible in the first two cases,
the real fix is to narrow the rcu_read_lock.
Reported-by: Jia-Ju Bai <baijiaju1990@163.com>
Reviewed-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_init_queue() will not return NULL pointer to its caller,
so it's better to replace IS_ERR_OR_NULL using IS_ERR in loop_add().
If in the future things change to check NULL pointer inside loop_add(),
we should return -ENOMEM as return code instead of PTR_ERR(NULL).
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add __exit annotation to cleanup helper which
is only called once in the module.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For cases where we can only fail with IO in-flight, we should be using
BLK_STS_DEV_RESOURCE instead of BLK_STS_RESOURCE. The latter refers to
system wide resource constraints.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The "cmd_slot_unal" semaphore is never used in a blocking way
but only as an atomic counter. Change the code to using
atomic_dec_if_positive() as a better API.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Prior patches ensured that any bio that interacts with a request_queue
is properly associated with a blkg. This makes bio->bi_css unnecessary
as blkg maintains a reference to blkcg already.
This removes the bio field bi_css and transfers corresponding uses to
access via bi_blkg.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Smatch complains that there is an off by one if the allocation fails in:
DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
In that situation, "i" would be point to one element beyond the end of
the unit[] array.
There is a second bug because the error handling calls
blk_mq_free_tag_set(&unit[i].tag_set); regardless of whether
"disk->queue" is NULL or non-NULL. So if blk_mq_init_sq_queue() fails,
then that means unit[i].tag_set->tags is NULL and it leads to an Oops.
It's easiest to call put_disk() before the goto to clean up the partial
iteration. Then the earlier unit[] elements are fully allocated so we
can remove the checks whether "disk->queue" is NULL and the code is
simpler.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__vdc_tx_trigger should only loop on EAGAIN a finite
number of times.
See commit adddc32d6f ("sunvnet: Do not spin in an
infinite loop when vio_ldc_send() returns EAGAIN") for detail.
Signed-off-by: Young Xiao <YangX92@hotmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAlvx2sAeHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGycgIAIuxobwt0RRKa0zO
ROS+34JGoC2yU2P9VdEGWdtxS6ANMVQgKPBhWL6s+xR89Kd+V4xSdJLD1pNTxxqP
0DCva0np1/Q4juH+JbU50v/lykoLgteZ0P0LBRGf1y8p3WiLPv45IbnNsMDNYhB2
7a8rOmZYakRY9CPznRDw3X8cJt3sddKgFJHIOGz1OQJVWtCD0KPGcJmQNsbDSagY
Zx6Z5BKSIdjRqaAdN5gDa1Pft3WQo7TpaQGl80lSsgr5LcjmscXA3sClOCy+25Mo
FZLx0PcwP+Efq8RTGzNK51WSOMa6d37hvjDqUAdQBOR0KbyjRyXQwyQVw/MGbPJs
7J3Pzm0=
=56Mt
-----END PGP SIGNATURE-----
Merge tag 'v4.20-rc3' into for-4.21/block
Merge in -rc3 to resolve a few conflicts, but also to get a few
important fixes that have gone into mainline since the block
4.21 branch was forked off (most notably the SCSI queue issue,
which is both a conflict AND needed fix).
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With the locking removed, it's unused. Kill it.
Fixes: 503f620f0c ("floppy: remove queue_lock around floppy_end_request")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_queue_max_hw_sectors can't do anything with queue_lock protection
so don't hold it.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is nothing the queue_lock could protect inside floppy_end_request,
so remove it.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With the legacy request path gone there is no good reason to keep
queue_lock as a pointer, we can always use the embedded lock now.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixed floppy and blk-cgroup missing conversions and half done edits.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With the legacy request path gone there is no real need to override the
queue_lock.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The umem card->lock and the block layer queue_lock are used for entirely
different resources. Stop using card->lock as the block layer
queue_lock.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The DRBD req_lock and block layer queue_lock are used for entirely
different resources. Stop using the req_lock as the block layer
queue_lock.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is nothing it could synchronize against, so don't go through
the pains of acquiring the lock.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 0a42e99b58 ("loop: Get rid of loop_index_mutex") forgot to
remove mutex_unlock(&loop_ctl_mutex) from loop_control_ioctl() when
replacing loop_index_mutex with loop_ctl_mutex.
Fixes: 0a42e99b58 ("loop: Get rid of loop_index_mutex")
Reported-by: syzbot <syzbot+c0138741c2290fc5e63f@syzkaller.appspotmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
LKP recently reported a hang at bootup in the floppy code:
[ 245.678853] INFO: task mount:580 blocked for more than 120 seconds.
[ 245.679906] Tainted: G T 4.19.0-rc6-00172-ga9f38e1 #1
[ 245.680959] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 245.682181] mount D 6372 580 1 0x00000004
[ 245.683023] Call Trace:
[ 245.683425] __schedule+0x2df/0x570
[ 245.683975] schedule+0x2d/0x80
[ 245.684476] schedule_timeout+0x19d/0x330
[ 245.685090] ? wait_for_common+0xa5/0x170
[ 245.685735] wait_for_common+0xac/0x170
[ 245.686339] ? do_sched_yield+0x90/0x90
[ 245.686935] wait_for_completion+0x12/0x20
[ 245.687571] __floppy_read_block_0+0xfb/0x150
[ 245.688244] ? floppy_resume+0x40/0x40
[ 245.688844] floppy_revalidate+0x20f/0x240
[ 245.689486] check_disk_change+0x43/0x60
[ 245.690087] floppy_open+0x1ea/0x360
[ 245.690653] __blkdev_get+0xb4/0x4d0
[ 245.691212] ? blkdev_get+0x1db/0x370
[ 245.691777] blkdev_get+0x1f3/0x370
[ 245.692351] ? path_put+0x15/0x20
[ 245.692871] ? lookup_bdev+0x4b/0x90
[ 245.693539] blkdev_get_by_path+0x3d/0x80
[ 245.694165] mount_bdev+0x2a/0x190
[ 245.694695] squashfs_mount+0x10/0x20
[ 245.695271] ? squashfs_alloc_inode+0x30/0x30
[ 245.695960] mount_fs+0xf/0x90
[ 245.696451] vfs_kern_mount+0x43/0x130
[ 245.697036] do_mount+0x187/0xc40
[ 245.697563] ? memdup_user+0x28/0x50
[ 245.698124] ksys_mount+0x60/0xc0
[ 245.698639] sys_mount+0x19/0x20
[ 245.699167] do_int80_syscall_32+0x61/0x130
[ 245.699813] entry_INT80_32+0xc7/0xc7
showing that we never complete that read request. The reason is that
the completion setup is racy - it initializes the completion event
AFTER submitting the IO, which means that the IO could complete
before/during the init. If it does, we are passing garbage to
complete() and we may sleep forever waiting for the event to
occur.
Fixes: 7b7b68bba5 ("floppy: bail out in open() if drive is not responding to block0 read")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Makes the code a whole lot easier to read.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a retries field to the internal request structure instead, which gets
set to zero on the first submission.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_softirq_done_fn is only used for the blk-mq path, so remove the
other branch. Also rename the function to better match the method name.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use the proper helper instead of manually iterating the scatterlist,
which is broken in the presence of chained S/G lists.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead create add to the icmd into struct mtip_cmd which can be unioned
with the scatterlist used for the normal I/O path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merging this function into the only callers makes the code flow easier.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There isn't much need for this helper - we can just calculate the offset
for the command header once late in the submission path and fill out
the ctba and ctbau fields there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Factor out a new is_stopped helper that matches the existing
is_se_active helper, and merge the trivial amount of remaining code
into the only caller. This also allows better error handling by
returning a BLK_STS_* directly instead of explicitly calling
blk_mq_end_request, and moving blk_mq_start_request closer to the
actual issue to hardware.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have all arguments at hand in mtip_hw_submit_io, so keep the
rq to sg mapping close to the dma_map_sg call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current sx8 code spends a lot of effort dealing with the fact that
tags are per-host, but there might be multiple queues. Now that the
driver has been converted to blk-mq it can take care of the blk-mq
tag_set concept that has been designed just for that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make the disk/queue alloc and free helpers per-port by moving the
trivial loops into the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have this functionality in sbitmap, but we don't export it in
blk-mq for users of the tags busy iteration. This can be useful
for stopping the iteration, if the caller doesn't need to find
more requests.
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The nested acquisition of loop_ctl_mutex (->lo_ctl_mutex back then) has
been introduced by commit f028f3b2f9 "loop: fix circular locking in
loop_clr_fd()" to fix lockdep complains about bd_mutex being acquired
after lo_ctl_mutex during partition rereading. Now that these are
properly fixed, let's stop fooling lockdep.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Code in loop_change_fd() drops reference to the old file (and also the
new file in a failure case) under loop_ctl_mutex. Similarly to a
situation in loop_set_fd() this can create a circular locking dependency
if this was the last reference holding the file open. Delay dropping of
the file reference until we have released loop_ctl_mutex.
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Calling blkdev_reread_part() under loop_ctl_mutex causes lockdep to
complain about circular lock dependency between bdev->bd_mutex and
lo->lo_ctl_mutex. The problem is that on loop device open or close
lo_open() and lo_release() get called with bdev->bd_mutex held and they
need to acquire loop_ctl_mutex. OTOH when loop_reread_partitions() is
called with loop_ctl_mutex held, it will call blkdev_reread_part() which
acquires bdev->bd_mutex. See syzbot report for details [1].
Move call to blkdev_reread_part() in __loop_clr_fd() from under
loop_ctl_mutex to finish fixing of the lockdep warning and the possible
deadlock.
[1] https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d1588
Reported-by: syzbot <syzbot+4684a000d5abdade83fac55b1e7d1f935ef1936e@syzkaller.appspotmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Calling loop_reread_partitions() under loop_ctl_mutex causes lockdep to
complain about circular lock dependency between bdev->bd_mutex and
lo->lo_ctl_mutex. The problem is that on loop device open or close
lo_open() and lo_release() get called with bdev->bd_mutex held and they
need to acquire loop_ctl_mutex. OTOH when loop_reread_partitions() is
called with loop_ctl_mutex held, it will call blkdev_reread_part() which
acquires bdev->bd_mutex. See syzbot report for details [1].
Move all calls of loop_rescan_partitions() out of loop_ctl_mutex to
avoid lockdep warning and fix deadlock possibility.
[1] https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d1588
Reported-by: syzbot <syzbot+4684a000d5abdade83fac55b1e7d1f935ef1936e@syzkaller.appspotmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The call of __blkdev_reread_part() from loop_reread_partition() happens
only when we need to invalidate partitions from loop_release(). Thus
move a detection for this into loop_clr_fd() and simplify
loop_reread_partition().
This makes loop_reread_partition() safe to use without loop_ctl_mutex
because we use only lo->lo_number and lo->lo_file_name in case of error
for reporting purposes (thus possibly reporting outdate information is
not a big deal) and we are safe from 'lo' going away under us by
elevated lo->lo_refcnt.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Push loop_ctl_mutex down to loop_change_fd(). We will need this to be
able to call loop_reread_partitions() without loop_ctl_mutex.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Push lo_ctl_mutex down to loop_set_fd(). We will need this to be able to
call loop_reread_partitions() without lo_ctl_mutex.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Push loop_ctl_mutex down to loop_set_status(). We will need this to be
able to call loop_reread_partitions() without loop_ctl_mutex.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Push loop_ctl_mutex down to loop_get_status() to avoid the unusual
convention that the function gets called with loop_ctl_mutex held and
releases it.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Lars Ellenberg