linux-stable.git/block/genhd.c, branch linux-5.17.y

block, loop: support partitions without scanning

2022-06-14T16:41:52+00:00

commit b9684a71fca793213378dd410cd11675d973eaa1 upstream.

Historically we did distinguish between a flag that surpressed partition
scanning, and a combinations of the minors variable and another flag if
any partitions were supported.  This was generally confusing and doesn't
make much sense, but some corner case uses of the loop driver actually
do want to support manually added partitions on a device that does not
actively scan for partitions.  To make things worsee the loop driver
also wants to dynamically toggle the scanning for partitions on a live
gendisk, which makes the disk->flags updates non-atomic.

Introduce a new GD_SUPPRESS_PART_SCAN bit in disk->state that disables
just scanning for partitions, and toggle that instead of GENHD_FL_NO_PART
in the loop driver.

Fixes: 1ebe2e5f9d68 ("block: remove GENHD_FL_EXT_DEVT")
Reported-by: Ming Lei 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Ming Lei 
Link: https://lore.kernel.org/r/20220527055806.1972352-1-hch@lst.de
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: Fix the maximum minor value is blk_alloc_ext_minor()

2022-04-08T11:58:57+00:00

commit d1868328dec5ae2cf210111025fcbc71f78dd5ca upstream.

ida_alloc_range(..., min, max, ...) returns values from min to max,
inclusive.

So, NR_EXT_DEVT is a valid idx returned by blk_alloc_ext_minor().

This is an issue because in device_add_disk(), this value is used in:
   ddev->devt = MKDEV(disk->major, disk->first_minor);
and NR_EXT_DEVT is '(1 << MINORBITS)'.

So, should 'disk->first_minor' be NR_EXT_DEVT, it would overflow.

Fixes: 22ae8ce8b892 ("block: simplify bdev/disk lookup in blkdev_get")
Signed-off-by: Christophe JAILLET 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/cc17199798312406b90834e433d2cefe8266823d.1648306232.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: update io_ticks when io hang

2022-04-08T11:57:35+00:00

[ Upstream commit 86d7331299fda7634b11c1b7c911432679d525a5 ]

When the inflight IOs are slow and no new IOs are issued, we expect
iostat could manifest the IO hang problem. However after
commit 5b18b5a73760 ("block: delete part_round_stats and switch to less
precise counting"), io_tick and time_in_queue will not be updated until
the end of IO, and the avgqu-sz and %util columns of iostat will be zero.

Because it has using stat.nsecs accumulation to express time_in_queue
which is not suitable to change, and may %util will express the status
better when io hang occur. To fix io_ticks, we use update_io_ticks and
inflight to update io_ticks when diskstats_show and part_stat_show
been called.

Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting")
Signed-off-by: Zhang Wensheng 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220217064247.4041435-1-zhangwensheng5@huawei.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: fix surprise removal for drivers calling blk_set_queue_dying

2022-02-17T14:54:03+00:00

Various block drivers call blk_set_queue_dying to mark a disk as dead due
to surprise removal events, but since commit 8e141f9eb803 that doesn't
work given that the GD_DEAD flag needs to be set to stop I/O.

Replace the driver calls to blk_set_queue_dying with a new (and properly
documented) blk_mark_disk_dead API, and fold blk_set_queue_dying into the
only remaining caller.

Fixes: 8e141f9eb803 ("block: drain file system I/O on del_gendisk")
Reported-by: Markus Blöchl 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Link: https://lore.kernel.org/r/20220217075231.1140-1-hch@lst.de
Signed-off-by: Jens Axboe

block: check minor range in device_add_disk()

2021-12-21T16:34:29+00:00

ioctl(fd, LOOP_CTL_ADD, 1048576) causes

  sysfs: cannot create duplicate filename '/dev/block/7:0'

message because such request is treated as if ioctl(fd, LOOP_CTL_ADD, 0)
due to MINORMASK == 1048575. Verify that all minor numbers for that device
fit in the minor range.

Reported-by: wangyangbo 
Signed-off-by: Tetsuo Handa 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/b1b19379-23ee-5379-0eb5-94bf5f79f1b4@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe

block: fix error unwinding in device_add_disk

2021-12-21T16:31:51+00:00

One device_add is called disk->ev will be freed by disk_release, so we
should free it twice.  Fix this by allocating disk->ev after device_add
so that the extra local unwinding can be removed entirely.

Based on an earlier patch from Tetsuo Handa.

Reported-by: syzbot 
Tested-by: syzbot 
Fixes: 83cbce9574462c6b ("block: add error handling for device_add_disk / add_disk")
Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211221161851.788424-1-hch@lst.de
Signed-off-by: Jens Axboe

blk-mq: move srcu from blk_mq_hw_ctx to request_queue

2021-12-03T21:51:29+00:00

In case of BLK_MQ_F_BLOCKING, per-hctx srcu is used to protect dispatch
critical area. However, this srcu instance stays at the end of hctx, and
it often takes standalone cacheline, often cold.

Inside srcu_read_lock() and srcu_read_unlock(), WRITE is always done on
the indirect percpu variable which is allocated from heap instead of
being embedded, srcu->srcu_idx is read only in srcu_read_lock(). It
doesn't matter if srcu structure stays in hctx or request queue.

So switch to per-request-queue srcu for protecting dispatch, and this
way simplifies quiesce a lot, not mention quiesce is always done on the
request queue wide.

Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20211203131534.3668411-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe

block: don't include in blk.h

2021-11-29T13:38:44+00:00

Not needed, shift it into the source files that need it instead.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211123185312.1432157-9-hch@lst.de
Signed-off-by: Jens Axboe

block: don't include blk-mq-sched.h in blk.h

2021-11-29T13:38:44+00:00

No needed, shift it into the source files that need it instead.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211123185312.1432157-5-hch@lst.de
Signed-off-by: Jens Axboe

block: don't set GENHD_FL_NO_PART for hidden gendisks

2021-11-29T13:38:35+00:00

Hidden gendisks can't be opened using blkdev_get_*, so we can't really
reach any of the partition scanning paths or partitioning ioctls except
for the initial partition scan from add_disk.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211122130625.1136848-13-hch@lst.de
Signed-off-by: Jens Axboe