Граф коммитов

373 Коммитов

Автор SHA1 Сообщение Дата
Ming Lei 1ccc12f224 block: loop:use kstatfs.f_bsize of backing file to set discard granularity
[ Upstream commit 06582bc86d ]

If backing file's filesystem has implemented ->fallocate(), we think the
loop device can support discard, then pass sb->s_blocksize as
discard_granularity. However, some underlying FS, such as overlayfs,
doesn't set sb->s_blocksize, and causes discard_granularity to be set as
zero, then the warning in __blkdev_issue_discard() is triggered.

Christoph suggested to pass kstatfs.f_bsize as discard granularity, and
this way is fine because kstatfs.f_bsize means 'Optimal transfer block
size', which still matches with definition of discard granularity.

So fix the issue by setting discard_granularity as kstatfs.f_bsize if it
is available, otherwise claims discard isn't supported.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reported-by: Pei Zhang <pezhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220126035830.296465-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:12:30 +01:00
Tetsuo Handa ced9b762f2 loop: Use pr_warn_once() for loop_control_remove() warning
[ Upstream commit e3f9387aea ]

kernel test robot reported that RCU stall via printk() flooding is
possible [1] when stress testing.

Link: https://lkml.kernel.org/r/20211129073709.GA18483@xsang-OptiPlex-9020 [1]
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-17 10:30:15 +01:00
Xie Yongji c0991182ac loop: Use blk_validate_block_size() to validate block size
commit af3c570fb0 upstream.

Remove loop_validate_block_size() and use the block layer helper
to validate block size.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20211026144015.188-4-xieyongji@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Tadeusz Struk <tadeusz.struk@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-21 13:44:13 +01:00
Tetsuo Handa 1c500ad706 loop: reduce the loop_ctl_mutex scope
syzbot is reporting circular locking problem at __loop_clr_fd() [1], for
commit a160c6159d ("block: add an optional probe callback to
major_names") is calling the module's probe function with major_names_lock
held.

Fortunately, since commit 990e78116d ("block: loop: fix deadlock
between open and remove") stopped holding loop_ctl_mutex in lo_open(),
current role of loop_ctl_mutex is to serialize access to loop_index_idr
and loop_add()/loop_remove(); in other words, management of id for IDR.
To avoid holding loop_ctl_mutex during whole add/remove operation, use
a bool flag to indicate whether the loop device is ready for use.

loop_unregister_transfer() which is called from cleanup_cryptoloop()
currently has possibility of use-after-free problem due to lack of
serialization between kfree() from loop_remove() from loop_control_remove()
and mutex_lock() from unregister_transfer_cb(). But since lo->lo_encryption
should be already NULL when this function is called due to module unload,
and commit 222013f9ac ("cryptoloop: add a deprecation warning")
indicates that we will remove this function shortly, this patch updates
this function to emit warning instead of checking lo->lo_encryption.

Holding loop_ctl_mutex in loop_exit() is pointless, for all users must
close /dev/loop-control and /dev/loop$num (in order to drop module's
refcount to 0) before loop_exit() starts, and nobody can open
/dev/loop-control or /dev/loop$num afterwards.

Link: https://syzkaller.appspot.com/bug?id=7bb10e8b62f83e4d445cdf4c13d69e407e629558 [1]
Reported-by: syzbot <syzbot+f61766d5763f9e7a118f@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/adb1e792-fc0e-ee81-7ea0-0906fc36419d@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-03 22:14:40 -06:00
Bart Van Assche 2112f5c133 loop: Select I/O scheduler 'none' from inside add_disk()
We noticed that the user interface of Android devices becomes very slow
under memory pressure. This is because Android uses the zram driver on top
of the loop driver for swapping, because under memory pressure the swap
code alternates reads and writes quickly, because mq-deadline is the
default scheduler for loop devices and because mq-deadline delays writes by
five seconds for such a workload with default settings. Fix this by making
the kernel select I/O scheduler 'none' from inside add_disk() for loop
devices. This default can be overridden at any time from user space,
e.g. via a udev rule. This approach has an advantage compared to changing
the I/O scheduler from userspace from 'mq-deadline' into 'none', namely
that synchronize_rcu() does not get called.

This patch changes the default I/O scheduler for loop devices from
'mq-deadline' into 'none'.

Additionally, this patch reduces the Android boot time on my test setup
with 0.5 seconds compared to configuring the loop I/O scheduler from user
space.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Martijn Coenen <maco@android.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210805174200.3250718-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-05 11:49:21 -06:00
Matteo Croce 9f65c489b6 loop: raise media_change event
Make the loop device raise a DISK_MEDIA_CHANGE event on attach or detach.

	# udevadm monitor -up |grep -e DISK_MEDIA_CHANGE -e DEVNAME &

	# losetup -f zero
	[    7.454235] loop0: detected capacity change from 0 to 16384
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop0
	DEVNAME=/dev/loop0
	DEVNAME=/dev/loop0

	# losetup -f zero
	[   10.205245] loop1: detected capacity change from 0 to 16384
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop1
	DEVNAME=/dev/loop1
	DEVNAME=/dev/loop1

	# losetup -f zero2
	[   13.532368] loop2: detected capacity change from 0 to 40960
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop2
	DEVNAME=/dev/loop2

	# losetup -D
	DEVNAME=/dev/loop1
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop1
	DEVNAME=/dev/loop2
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop2
	DEVNAME=/dev/loop0
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop0

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-7-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:29 -06:00
Christoph Hellwig 4b2731226d loop: don't grab a reference to the block device
The whole device block device won't be removed while the disk is still
alive, so don't bother to grab a reference to it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Ming Lei <ming.lei@rehat.com>
Reviewed-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Link: https://lore.kernel.org/r/20210722075402.983367-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Tetsuo Handa 3ce6e1f662 loop: reintroduce global lock for safe loop_validate_file() traversal
Commit 6cc8e74308 ("loop: scale loop device by introducing per
device lock") re-opened a race window for NULL pointer dereference at
loop_validate_file() where commit 310ca162d7 ("block/loop: Use
global lock for ioctl() operation.") has closed.

Although we need to guarantee that other loop devices will not change
during traversal, we can't take remote "struct loop_device"->lo_mutex
inside loop_validate_file() in order to avoid AB-BA deadlock. Therefore,
introduce a global lock dedicated for loop_validate_file() which is
conditionally taken before local "struct loop_device"->lo_mutex is taken.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6cc8e74308 ("loop: scale loop device by introducing per device lock")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-07-23 10:18:25 -06:00
Tetsuo Handa 585af8ede7 loop: remove unused variable in loop_set_status()
Commit 0384264ea8 ("block: pass a gendisk to bdev_disk_changed")
changed to pass lo->lo_disk instead of lo->lo_device.

Fixes: 0384264ea8 ("block: pass a gendisk to bdev_disk_changed")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/20210702152714.7978-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-07-02 09:28:42 -06:00
Christoph Hellwig 8e60947d2f loop: rewrite loop_exit using idr_for_each_entry
Use idr_for_each_entry to simplify removing all devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig b984808146 loop: split loop_lookup
loop_lookup has two callers - one wants to do the a find by index and the
other wants any unbound loop device.  Open code the respective
functionality in each caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210623145908.92973-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig e5d66a1032 loop: don't allow deleting an unspecified loop device
Passing a negative index to loop_lookup while return any unbound device.
Doing that for a delete does not make much sense, so add check to
explicitly reject that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210623145908.92973-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig 18d1f200b3 loop: move loop_ctl_mutex locking into loop_add
Move acquiring and releasing loop_ctl_mutex from the callers into
loop_add.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig f9d107644a loop: split loop_control_ioctl
Split loop_control_ioctl into a helper for each command.  This keeps the
code nicely separated for the upcoming locking changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig 4157fe0b3d loop: don't call loop_lookup before adding a loop device
loop_add returns the right error if the slot wasn't available.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210623145908.92973-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig d6da83d072 loop: remove the l argument to loop_add
None of the callers cares about the allocated struct loop_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig bd5c39edad loop: reduce loop_ctl_mutex coverage in loop_exit
loop_ctl_mutex is only needed to iterate the IDR for removing the loop
devices, so reduce the coverage.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Christoph Hellwig 8b52d8be86 loop: reorder loop_exit
Unregister the misc and blockdevice first to prevent further access,
and only then iterate to remove the devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-30 15:34:13 -06:00
Linus Torvalds 440462198d for-5.14/drivers-2021-06-29
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmDbd5UQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpvsNEADCJKP81boFzRcdJo7EqaNDAzZyKOIg9Oq7
 4GZE0Wm0SgA6+04bKrNVd9KLcKvQ+NC1pK7UJemSSH2y9ir+zHfyYgAV0/+wFmYm
 NgHlDjBvf80XSI5wezcb6MxZT+R7IaIpDsW1ZvV9hFtPSncn5o2OIWiSdJtHT/Rv
 enlgZPc7OwNWoVMX8eR58IoO0k3S6GLpctUZHt/AUukaKgoOks0X523qhEPf3Upr
 RkbIZuqLWVgpdT6457iSE/OijUczD4thTI8bdprxzhgimOm2vV52sO6F5HtHc7GX
 qW+PWYUaiUk7UpObuOuyv0yyUG45ii73iY1W0w66RiyCjVTgtpdwwMQ38VlBcoOg
 zcE1jneAEJt6TiS6zfRaER/10JoCIG4gp1+apPuaXud/o3BqWI0cagVHAgaLziBI
 F7bDJkbJZIR6GrWMgemBI+mc5/LACBePxzPGLScKFptejtQ/ysfZQ6aCLROJWB2U
 4EnysAaUBf6tywj30JqfQvqFNGkHIgY95FKiXJW6GzqqwgBouNf48vS15BgkwI+2
 EijcqUhlOVNfc3RIc0ZL5c9KcPIN9t5sqBrWZe3wgCErhxAx6w6Za9nDdP+US9bl
 /apCpvDFlu59g8n1wtkNE/uC+XqdKDwsplYhnfpX0FGni5wIknhQq3bSe4dPFgSn
 pG5VMrw3pA==
 =D6dS
 -----END PGP SIGNATURE-----

Merge tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Pretty calm round, mostly just NVMe and a bit of MD:

   - NVMe updates (via Christoph)
        - improve the APST configuration algorithm (Alexey Bogoslavsky)
        - look for StorageD3Enable on companion ACPI device
          (Mario Limonciello)
        - allow selecting the network interface for TCP connections
          (Martin Belanger)
        - misc cleanups (Amit Engel, Chaitanya Kulkarni, Colin Ian King,
          Christoph)
        - move the ACPI StorageD3 code to drivers/acpi/ and add quirks
          for certain AMD CPUs (Mario Limonciello)
        - zoned device support for nvmet (Chaitanya Kulkarni)
        - fix the rules for changing the serial number in nvmet
          (Noam Gottlieb)
        - various small fixes and cleanups (Dan Carpenter, JK Kim,
          Chaitanya Kulkarni, Hannes Reinecke, Wesley Sheng, Geert
          Uytterhoeven, Daniel Wagner)

   - MD updates (Via Song)
        - iostats rewrite (Guoqing Jiang)
        - raid5 lock contention optimization (Gal Ofri)

   - Fall through warning fix (Gustavo)

   - Misc fixes (Gustavo, Jiapeng)"

* tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block: (78 commits)
  nvmet: use NVMET_MAX_NAMESPACES to set nn value
  loop: Fix missing discard support when using LOOP_CONFIGURE
  nvme.h: add missing nvme_lba_range_type endianness annotations
  nvme: remove zeroout memset call for struct
  nvme-pci: remove zeroout memset call for struct
  nvmet: remove zeroout memset call for struct
  nvmet: add ZBD over ZNS backend support
  nvmet: add Command Set Identifier support
  nvmet: add nvmet_req_bio put helper for backends
  nvmet: add req cns error complete helper
  block: export blk_next_bio()
  nvmet: remove local variable
  nvmet: use nvme status value directly
  nvmet: use u32 type for the local variable nsid
  nvmet: use u32 for nvmet_subsys max_nsid
  nvmet: use req->cmd directly in file-ns fast path
  nvmet: use req->cmd directly in bdev-ns fast path
  nvmet: make ver stable once connection established
  nvmet: allow mn change if subsys not discovered
  nvmet: make sn stable once connection was established
  ...
2021-06-30 12:21:16 -07:00
Linus Torvalds df668a5fe4 for-5.14/block-2021-06-29
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmDbXAwQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpr0HEADDJaSgjpnWQwH1RVLNagJa9KnktxZYsEs+
 as3QmDdpKRG3rEC9bdE7FLe/xq3WBaO5j1hTQ9P6IguqLyS1Df72DtTlKyaCrZoe
 zv9eIlY4lZUfksE2nzWmlN9uG0FBVXeEQpHCLSNbUZeK1zvV6+NNhQqw2kc0sEqu
 hReUFeMUbsMcu/w5T3XMVJNsTMCql9wta2H0q5hONQyJQSrIwa1D+sUdE5I8fO4j
 bnoYX9yxHX26EztX1UJiGRgoq5Trz7LY7hAfljKSkewpFwiHE2vBdq2L0C2RKsIV
 tTs2DjMCMQyPNeA7WAG8HlR4aPG+7+/fuBP1KJHkykjWXglWN7OqISuBv6rrBgQs
 gNRnZ4qmb1CzD6aLEBk59nHt6po6eMxXIW856YktKy8rKcrgK29qP44Z+oomkPKo
 ZjQ0wqN5CvpObM/dIKxl9bAJ4zQDHBt49d5nTTQLfWl/mgevu6ZNWD/hONyCQmFy
 zKKqQ/wkxWHutOsjC5/MKNb3ZRNH9tt9X+HfULO2DU6IqqifYw/ex4z4MVsBopJC
 7pPfd81kgC73TgXe1AaCwHqNWsrqYCuTK0ew1CtGudlS3lucMwtap4GBiCgg5gbu
 M8pEgwO4OcCLHyRUc8zdfqI7HumbprbFmojPkwGSEe0ofVD74lMhzbUj5jvTYY2B
 t8D2XcgyOA==
 =lhon
 -----END PGP SIGNATURE-----

Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:

 - disk events cleanup (Christoph)

 - gendisk and request queue allocation simplifications (Christoph)

 - bdev_disk_changed cleanups (Christoph)

 - IO priority improvements (Bart)

 - Chained bio completion trace fix (Edward)

 - blk-wbt fixes (Jan)

 - blk-wbt enable/disable fix (Zhang)

 - Scheduler dispatch improvements (Jan, Ming)

 - Shared tagset scheduler improvements (John)

 - BFQ updates (Paolo, Luca, Pietro)

 - BFQ lock inversion fix (Jan)

 - Documentation improvements (Kir)

 - CLONE_IO block cgroup fix (Tejun)

 - Remove of ancient and deprecated block dump feature (zhangyi)

 - Discard merge fix (Ming)

 - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas,
   Yang)

* tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits)
  block: fix discard request merge
  block/mq-deadline: Remove a WARN_ON_ONCE() call
  blk-mq: update hctx->dispatch_busy in case of real scheduler
  blk: Fix lock inversion between ioc lock and bfqd lock
  bfq: Remove merged request already in bfq_requests_merged()
  block: pass a gendisk to bdev_disk_changed
  block: move bdev_disk_changed
  block: add the events* attributes to disk_attrs
  block: move the disk events code to a separate file
  block: fix trace completion for chained bio
  block/partitions/msdos: Fix typo inidicator -> indicator
  block, bfq: reset waker pointer with shared queues
  block, bfq: check waker only for queues with no in-flight I/O
  block, bfq: avoid delayed merge of async queues
  block, bfq: boost throughput by extending queue-merging times
  block, bfq: consider also creation time in delayed stable merge
  block, bfq: fix delayed stable merge check
  block, bfq: let also stably merged queues enjoy weight raising
  blk-wbt: make sure throttle is enabled properly
  blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled()
  ...
2021-06-30 12:12:56 -07:00
Dan Schatzberg c74d40e8b5 loop: charge i/o to mem and blk cg
The current code only associates with the existing blkcg when aio is used
to access the backing file.  This patch covers all types of i/o to the
backing file and also associates the memcg so if the backing file is on
tmpfs, memory is charged appropriately.

This patch also exports cgroup_get_e_css and int_active_memcg so it can be
used by the loop module.

Link: https://lkml.kernel.org/r/20210610173944.1203706-4-schatzberg.dan@gmail.com
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Chris Down <chris@chrisdown.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:50 -07:00
Dan Schatzberg 87579e9b7d loop: use worker per cgroup instead of kworker
Patch series "Charge loop device i/o to issuing cgroup", v14.

The loop device runs all i/o to the backing file on a separate kworker
thread which results in all i/o being charged to the root cgroup.  This
allows a loop device to be used to trivially bypass resource limits and
other policy.  This patch series fixes this gap in accounting.

A simple script to demonstrate this behavior on cgroupv2 machine:

'''
#!/bin/bash
set -e

CGROUP=/sys/fs/cgroup/test.slice
LOOP_DEV=/dev/loop0

if [[ ! -d $CGROUP ]]
then
    sudo mkdir $CGROUP
fi

grep oom_kill $CGROUP/memory.events

# Set a memory limit, write more than that limit to tmpfs -> OOM kill
sudo unshare -m bash -c "
echo \$\$ > $CGROUP/cgroup.procs;
echo 0 > $CGROUP/memory.swap.max;
echo 64M > $CGROUP/memory.max;
mount -t tmpfs -o size=512m tmpfs /tmp;
dd if=/dev/zero of=/tmp/file bs=1M count=256" || true

grep oom_kill $CGROUP/memory.events

# Set a memory limit, write more than that limit through loopback
# device -> no OOM kill
sudo unshare -m bash -c "
echo \$\$ > $CGROUP/cgroup.procs;
echo 0 > $CGROUP/memory.swap.max;
echo 64M > $CGROUP/memory.max;
mount -t tmpfs -o size=512m tmpfs /tmp;
truncate -s 512m /tmp/backing_file
losetup $LOOP_DEV /tmp/backing_file
dd if=/dev/zero of=$LOOP_DEV bs=1M count=256;
losetup -D $LOOP_DEV" || true

grep oom_kill $CGROUP/memory.events
'''

Naively charging cgroups could result in priority inversions through the
single kworker thread in the case where multiple cgroups are
reading/writing to the same loop device.  This patch series does some
minor modification to the loop driver so that each cgroup can make forward
progress independently to avoid this inversion.

With this patch series applied, the above script triggers OOM kills when
writing through the loop device as expected.

This patch (of 3):

Existing uses of loop device may have multiple cgroups reading/writing to
the same device.  Simply charging resources for I/O to the backing file
could result in priority inversion where one cgroup gets synchronously
blocked, holding up all other I/O to the loop device.

In order to avoid this priority inversion, we use a single workqueue where
each work item is a "struct loop_worker" which contains a queue of struct
loop_cmds to issue.  The loop device maintains a tree mapping blk css_id
-> loop_worker.  This allows each cgroup to independently make forward
progress issuing I/O to the backing file.

There is also a single queue for I/O associated with the rootcg which can
be used in cases of extreme memory shortage where we cannot allocate a
loop_worker.

The locking for the tree and queues is fairly heavy handed - we acquire a
per-loop-device spinlock any time either is accessed.  The existing
implementation serializes all I/O through a single thread anyways, so I
don't believe this is any worse.

[colin.king@canonical.com: fixes]

Link: https://lkml.kernel.org/r/20210610173944.1203706-1-schatzberg.dan@gmail.com
Link: https://lkml.kernel.org/r/20210610173944.1203706-2-schatzberg.dan@gmail.com
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:50 -07:00
Christoph Hellwig 0384264ea8 block: pass a gendisk to bdev_disk_changed
bdev_disk_changed can only operate on whole devices.  Make that clear
by passing a gendisk instead of the struct block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210624123240.441814-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-24 12:01:06 -06:00
Kristian Klausen 2b9ac22b12 loop: Fix missing discard support when using LOOP_CONFIGURE
Without calling loop_config_discard() the discard flag and parameters
aren't set/updated for the loop device and worst-case they could
indicate discard support when it isn't the case (ex: if the
LOOP_SET_STATUS ioctl was used with a different file prior to
LOOP_CONFIGURE).

Cc: <stable@vger.kernel.org> # 5.8.x-
Fixes: 3448914e8c ("loop: Add LOOP_CONFIGURE ioctl")
Signed-off-by: Kristian Klausen <kristian@klausen.dk>
Link: https://lore.kernel.org/r/20210618115157.31452-1-kristian@klausen.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-18 08:52:37 -06:00
Christoph Hellwig 6a03cd9843 loop: fix order of cleaning up the queue and freeing the tagset
We must release the queue before freeing the tagset.

Fixes: 1c99502fae ("loop: use blk_mq_alloc_disk and blk_cleanup_disk")
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-16 06:53:51 -06:00
Linus Torvalds efc1fd601a block-5.13-2021-06-12
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmDEwCgQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgphOPD/0Zv2qkOcuYm/0pRjdU0mXRBA5ImJ5JwJKA
 XPe/sm+9JP5CtnP6czyWQFI2oMGwUBIukYfy0JEeZ4ydoAulzflgQionKRy56e13
 SFxTVhvrPB9kAIGQ6/xPC20VAZNMDnNgaZMJJnrIoyBRm/5PKUE3Go3W9IjmuVJa
 SzPsOB+TM21s03RCsi2MtJjwbfivJlfDBdvYlThMmxfKCgTpQOHNJow8FsL7P94u
 RM0jQ2jCbjaHYW2+sHuSRDQF1CHjXoeq9ewrBvnjBLSLBNSrXrdN+slXNzxhAQ2a
 nXp26JUs102duclHzE2xhXQhYwOYyPwKbBUmTppNv8DBLgqV/mU/KCLc6S1lDkw0
 SKnCBzvrUKgCGIBe/j4eQLvlTO0ckvKdsWjdegj7naajK+VQiTgLw/UuJCAIPI+V
 7FNJh0afr3hfVGZnfspIKuvaQ4omP+vCvKhQZEa14uu2pN2WvyTNVYTn8vbprXEl
 Q36Aw7/yAzSXYAoUDP+QX2p+WIInpOsiInpa/CETvH43aP6uf18I7ZEjuDr2zJxP
 RFpt/ApkWm8D7vq1p4QEG6FLaoGn8hsoChb6Zhax+Ek8XyoOWWs6oJHr19hfMPjc
 s+sGDk1+FZqihpWEvNMHwELMbwegKnDSlbRFVu8od3DAPTBfQKHMlQtg2OPrGrA3
 2q7/HsWsOw==
 =LOdw
 -----END PGP SIGNATURE-----

Merge tag 'block-5.13-2021-06-12' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A few fixes that should go into 5.13:

   - Fix a regression deadlock introduced in this release between open
     and remove of a bdev (Christoph)

   - Fix an async_xor md regression in this release (Xiao)

   - Fix bcache oversized read issue (Coly)"

* tag 'block-5.13-2021-06-12' of git://git.kernel.dk/linux-block:
  block: loop: fix deadlock between open and remove
  async_xor: check src_offs is not NULL before updating it
  bcache: avoid oversized read request in cache missing code path
  bcache: remove bcache device self-defined readahead
2021-06-12 11:59:58 -07:00
Christoph Hellwig 1c99502fae loop: use blk_mq_alloc_disk and blk_cleanup_disk
Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-11 11:53:03 -06:00
Christoph Hellwig 990e78116d block: loop: fix deadlock between open and remove
Commit c76f48eb5c ("block: take bd_mutex around delete_partitions in
del_gendisk") adds disk->part0->bd_mutex in del_gendisk(), this way
causes the following AB/BA deadlock between removing loop and opening
loop:

 1) loop_control_ioctl(LOOP_CTL_REMOVE)
     -> mutex_lock(&loop_ctl_mutex)
     -> del_gendisk
         -> mutex_lock(&disk->part0->bd_mutex)

 2) blkdev_get_by_dev
     -> mutex_lock(&disk->part0->bd_mutex)
     -> lo_open
         -> mutex_lock(&loop_ctl_mutex)

Add a new Lo_deleting state to remove the need for clearing
->private_data and thus holding loop_ctl_mutex in the ioctl
LOOP_CTL_REMOVE path.

Based on an analysis and earlier patch from
Ming Lei <ming.lei@redhat.com>.

Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: c76f48eb5c ("block: take bd_mutex around delete_partitions in del_gendisk")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210605140950.5800-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-11 11:50:54 -06:00
Christoph Hellwig a8698707a1 block: move bd_mutex to struct gendisk
Replace the per-block device bd_mutex with a per-gendisk open_mutex,
thus simplifying locking wherever we deal with partitions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:44:32 -06:00
Matthew Wilcox (Oracle) 4ee60ec156 include: remove pagemap.h from blkdev.h
My UEK-derived config has 1030 files depending on pagemap.h before this
change.  Afterwards, just 326 files need to be rebuilt when I touch
pagemap.h.  I think blkdev.h is probably included too widely, but
untangling that dependency is harder and this solves my problem.  x86
allmodconfig builds, but there may be implicit include problems on other
architectures.

Link: https://lkml.kernel.org/r/20210309195747.283796-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>		[nvdimm]
Acked-by: Jens Axboe <axboe@kernel.dk>				[block]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Coly Li <colyli@suse.de>				[bcache]
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>	[scsi]
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:11 -07:00
Linus Torvalds 3ab6608e66 block-5.12-2021-02-27
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmA6njIQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgprolD/9zWti9LsZvA7yE+PhVwrwF3CsNzLfQlClw
 99HaA7HxtAc/VLJrnD/SubhCAPdBC5B2xPv6faajdwF2iUR3Rr1Uc93CQ3uP2KKq
 kvm6ALTpzPTMI6YSABhY74sg9BkkoDbMo54JQYVQPleiE+5eDLbuFZck6ObfUHyY
 a4aaImlndWp/t14GzrClL4hucF+5KJy846P+QCVclkh0yl8xSsqZ5LIFU7tu3iQb
 HpZ5HKLT/2ma/EOr3wknnsIe97AUZQU0q5aMparhYlm+qR511eop3QXx850FL/oC
 tEGceKLij6qazmkiocKVzML8Fs+Y9/a4vCMjLCScWJmzDlmKdlH2uudeahN6b9Hm
 15qRQHOjl1Hc2bdr5ZVn87nq9RWhSm18C+SRMwOKHCOnEhwxqM3RjRfAgj4BJ6QB
 PFbFqdY+8Y1YLPFmn9hph72ePaEcN4L2IXW6TI/WX8mot8ODAnkq9Hr38dKwzO+i
 0mon6DVyJKKho6XwvVu5IYurkR2beQprjeVUxwZjjT6DxUgsc+J6itK5LDHFSkeZ
 qZlXn5Di8MkiXg0DFJYDQiFXnO0Z5GlRWOGPVfBaOr3x+1dqzDdHGw4oz1oGqvnr
 GNNYCsYIpDGm7eauX5lqL5MUFpjqRCceXy5JSHPhnWWw617nYkr4H9jdsV9HiTX1
 tQFx05QW3w==
 =ccMs
 -----END PGP SIGNATURE-----

Merge tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "A few stragglers (and one due to me missing it originally), and fixes
  for changes in this merge window mostly. In particular:

   - blktrace cleanups (Chaitanya, Greg)

   - Kill dead blk_pm_* functions (Bart)

   - Fixes for the bio alloc changes (Christoph)

   - Fix for the partition changes (Christoph, Ming)

   - Fix for turning off iopoll with polled IO inflight (Jeffle)

   - nbd disconnect fix (Josef)

   - loop fsync error fix (Mauricio)

   - kyber update depth fix (Yang)

   - max_sectors alignment fix (Mikulas)

   - Add bio_max_segs helper (Matthew)"

* tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block: (21 commits)
  block: Add bio_max_segs
  blktrace: fix documentation for blk_fill_rw()
  block: memory allocations in bounce_clone_bio must not fail
  block: remove the gfp_mask argument to bounce_clone_bio
  block: fix bounce_clone_bio for passthrough bios
  block-crypto-fallback: use a bio_set for splitting bios
  block: fix logging on capacity change
  blk-settings: align max_sectors on "logical_block_size" boundary
  block: reopen the device in blkdev_reread_part
  block: don't skip empty device in in disk_uevent
  blktrace: remove debugfs file dentries from struct blk_trace
  nbd: handle device refs for DESTROY_ON_DISCONNECT properly
  kyber: introduce kyber_depth_updated()
  loop: fix I/O error on fsync() in detached loop devices
  block: fix potential IO hang when turning off io_poll
  block: get rid of the trace rq insert wrapper
  blktrace: fix blk_rq_merge documentation
  blktrace: fix blk_rq_issue documentation
  blktrace: add blk_fill_rwbs documentation comment
  block: remove superfluous param in blk_fill_rwbs()
  ...
2021-02-28 11:23:38 -08:00
Linus Torvalds 5ceabb6078 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff pile - no common topic here"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  whack-a-mole: don't open-code iminor/imajor
  9p: fix misuse of sscanf() in v9fs_stat2inode()
  audit_alloc_mark(): don't open-code ERR_CAST()
  fs/inode.c: make inode_init_always() initialize i_ino to 0
  vfs: don't unnecessarily clone write access for writable fds
2021-02-27 08:07:12 -08:00
Al Viro 6f24784f00 whack-a-mole: don't open-code iminor/imajor
several instances creeped back into the tree...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-02-23 10:25:29 -05:00
Mauricio Faria de Oliveira 4ceddce55e loop: fix I/O error on fsync() in detached loop devices
There's an I/O error on fsync() in a detached loop device
if it has been previously attached.

The issue is write cache is enabled in the attach path in
loop_configure() but it isn't disabled in the detach path;
thus it remains enabled in the block device regardless of
whether it is attached or not.

Now fsync() can get an I/O request that will just be failed
later in loop_queue_rq() as device's state is not 'Lo_bound'.

So, disable write cache in the detach path.

Do so based on the queue flag, not the loop device flag for
read-only (used to enable) as the queue flag can be changed
via sysfs even on read-only loop devices (e.g., losetup -r.)

Test-case:

    # DEV=/dev/loop7

    # IMG=/tmp/image
    # truncate --size 1M $IMG

    # losetup $DEV $IMG
    # losetup -d $DEV

Before:

    # strace -e fsync parted -s $DEV print 2>&1 | grep fsync
    fsync(3)                                = -1 EIO (Input/output error)
    Warning: Error fsyncing/closing /dev/loop7: Input/output error
    [  982.529929] blk_update_request: I/O error, dev loop7, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0

After:

    # strace -e fsync parted -s $DEV print 2>&1 | grep fsync
    fsync(3)                                = 0

Co-developed-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Tested-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-22 08:43:57 -07:00
Pavel Tatashin 6cc8e74308 loop: scale loop device by introducing per device lock
Currently, loop device has only one global lock: loop_ctl_mutex.

This becomes hot in scenarios where many loop devices are used.

Scale it by introducing per-device lock: lo_mutex that protects
modifications of all fields in struct loop_device.

Keep loop_ctl_mutex to protect global data: loop_index_idr, loop_lookup,
loop_add.

The new lock ordering requirement is that loop_ctl_mutex must be taken
before lo_mutex.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-26 13:08:54 -07:00
Linus Torvalds 69f637c335 for-5.11/drivers-2020-12-14
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl/XgdYQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpjTBD/4me2TNvGOogbcL0b1leAotndJ7spI/IcFM
 NUMNy3pOGuRBcRjwle85xq44puAjlNkZE2LLatem5sT7ZvS+8lPNnOIoTYgfaCjt
 PhKx2sKlLumVm3BwymYAPcPtke4fikGG15Mwu5nX1oOehmyGrjObGAr3Lo6gexCT
 tQoCOczVqaTsV+iTXrLlmgEgs07J9Tm93uh2cNR8Jgroxb8ivuWeUq4YgbV4kWk+
 Y8XvOyVE/yba0vQf5/hHtWuVoC6RdELnqZ6NCkcP/EicdBecwk1GMJAej1S3zPS1
 0BT7GSFTpm3YUHcygD6LRmRg4I/BmWDTDtMi84+jLat6VvSG1HwIm//qHiCJh3ku
 SlvFZENIWAv5LP92x2vlR5Lt7uE3GK2V/5Pxt2fekyzCth6mzu+hLH4CBPQ3xgyd
 E1JqIQ/ilbXstp+EYoivV5x8yltZQnKEZRopws0EOqj1LsmDPj9XT1wzE9RnB0o+
 PWu/DNhQFhhcmP7Z8uLgPiKIVpyGs+vjxiJLlTtGDFTCy6M5JbcgzGkEkSmnybxH
 7lSanjpLt1dWj85FBMc6fNtJkv2rBPfb4+j0d1kZ45Dzcr4umirGIh7wtCHcgc83
 brmXSt29hlKHseSHMMuNWK8haXcgAE7gq9tD8GZ/kzM7+vkmLLxHJa22Qhq5rp4w
 URPeaBaQJw==
 =ayp2
 -----END PGP SIGNATURE-----

Merge tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Nothing major in here:

   - NVMe pull request from Christoph:
        - nvmet passthrough improvements (Chaitanya Kulkarni)
        - fcloop error injection support (James Smart)
        - read-only support for zoned namespaces without Zone Append
          (Javier González)
        - improve some error message (Minwoo Im)
        - reject I/O to offline fabrics namespaces (Victor Gladkov)
        - PCI queue allocation cleanups (Niklas Schnelle)
        - remove an unused allocation in nvmet (Amit Engel)
        - a Kconfig spelling fix (Colin Ian King)
        - nvme_req_qid simplication (Baolin Wang)

   - MD pull request from Song:
        - Fix race condition in md_ioctl() (Dae R. Jeong)
        - Initialize read_slot properly for raid10 (Kevin Vigor)
        - Code cleanup (Pankaj Gupta)
        - md-cluster resync/reshape fix (Zhao Heming)

   - Move null_blk into its own directory (Damien Le Moal)

   - null_blk zone and discard improvements (Damien Le Moal)

   - bcache race fix (Dongsheng Yang)

   - Set of rnbd fixes/improvements (Gioh Kim, Guoqing Jiang, Jack Wang,
     Lutz Pogrell, Md Haris Iqbal)

   - lightnvm NULL pointer deref fix (tangzhenhao)

   - sr in_interrupt() removal (Sebastian Andrzej Siewior)

   - FC endpoint security support for s390/dasd (Jan Höppner, Sebastian
     Ott, Vineeth Vijayan). From the s390 arch guys, arch bits included
     as it made it easier for them to funnel the feature through the
     block driver tree.

   - Follow up fixes (Colin Ian King)"

* tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block: (64 commits)
  block: drop dead assignments in loop_init()
  sr: Remove in_interrupt() usage in sr_init_command().
  sr: Switch the sector size back to 2048 if sr_read_sector() changed it.
  cdrom: Reset sector_size back it is not 2048.
  drivers/lightnvm: fix a null-ptr-deref bug in pblk-core.c
  null_blk: Move driver into its own directory
  null_blk: Allow controlling max_hw_sectors limit
  null_blk: discard zones on reset
  null_blk: cleanup discard handling
  null_blk: Improve implicit zone close
  null_blk: improve zone locking
  block: Align max_hw_sectors to logical blocksize
  null_blk: Fail zone append to conventional zones
  null_blk: Fix zone size initialization
  bcache: fix race between setting bdev state to none and new write request direct to backing
  block/rnbd: fix a null pointer dereference on dev->blk_symlink_name
  block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name
  block/rnbd: call kobject_put in the failure path
  Documentation/ABI/rnbd-srv: add document for force_close
  block/rnbd-srv: close a mapped device from server side.
  ...
2020-12-16 13:09:32 -08:00
Lukas Bulwahn aeb2b0b1a3 block: drop dead assignments in loop_init()
Commit 8410d38c25 ("loop: use __register_blkdev to allocate devices on
demand") simplified loop_init(); so computing the range of the block region
is not required anymore and can be dropped.

Drop dead assignments in loop_init().

As compilers will detect these unneeded assignments and optimize this,
the resulting object code is identical before and after this change.

No functional change. No change in object code.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-12 11:18:56 -07:00
Christoph Hellwig a782483cc1 block: remove the nr_sects field in struct hd_struct
Now that the hd_struct always has a block device attached to it, there is
no need for having two size field that just get out of sync.

Additionally the field in hd_struct did not use proper serialization,
possibly allowing for torn writes.  By only using the block_device field
this problem also gets fixed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de>			[bcache]
Acked-by: Chao Yu <yuchao0@huawei.com>			[f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig 37c3fc9abb block: simplify the block device claiming interface
Stop passing the whole device as a separate argument given that it
can be trivially deducted and cleanup the !holder debug check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig a954ea8120 block: remove ->bd_contains
Now that each hd_struct has a reference to the corresponding
block_device, there is no need for the bd_contains pointer.  Add
a bdev_whole() helper to look up the whole device block_device
struture instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig 4e7b5671c6 block: remove i_bdev
Switch the block device lookup interfaces to directly work with a dev_t
so that struct block_device references are only acquired by the
blkdev_get variants (and the blk-cgroup special case).  This means that
we now don't need an extra reference in the inode and can generally
simplify handling of struct block_device to keep the lookups contained
in the core block layer code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Coly Li <colyli@suse.de>		[bcache]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig f46f2a3198 loop: do not call set_blocksize
set_blocksize is used by file systems to use their preferred buffer cache
block size.  Block drivers should not set it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig 449f4ec989 block: remove the update_bdev parameter to set_capacity_revalidate_and_notify
The update_bdev argument is always set to true, so remove it.  Also
rename the function to the slighly less verbose set_capacity_and_notify,
as propagating the disk size to the block device isn't really
revalidation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:34:14 -07:00
Christoph Hellwig 3b4f85d02a loop: let set_capacity_revalidate_and_notify update the bdev size
There is no good reason to call revalidate_disk_size separately.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:34:14 -07:00
Christoph Hellwig 8410d38c25 loop: use __register_blkdev to allocate devices on demand
Use the simpler mechanism attached to major_name to allocate a brd device
when a currently unregistered minor is accessed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:30 -07:00
Christoph Hellwig 7a2f0ce19f loop: use set_disk_ro
Use set_disk_ro instead of set_device_ro to match all other block
drivers and to ensure all partitions mirror the read-only flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:29 -07:00
Petr Vorel c01a21b777 loop: Fix occasional uevent drop
Commit 716ad0986c ("loop: Switch to set_capacity_revalidate_and_notify")
causes an occasional drop of loop device uevent, which are no longer
triggered in loop_set_size() but in a different part of code.

Bug is reproducible with LTP test uevent01 [1]:

i=0; while true; do
    i=$((i+1)); echo "== $i =="
    lsmod |grep -q loop && rmmod -f loop
    ./uevent01 || break
done

Put back triggering through code called in loop_set_size().

Fix required to add yet another parameter to
set_capacity_revalidate_and_notify().

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/uevents/uevent01.c

[hch: rebased on a different change to the prototype of
 set_capacity_revalidate_and_notify]

Cc: stable@vger.kernel.org # v5.9
Fixes: 716ad0986c ("loop: Switch to set_capacity_revalidate_and_notify")
Reported-by: <ltp@lists.linux.it>
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-12 13:59:04 -07:00
Christoph Hellwig 611bee526b block: replace bd_set_size with bd_set_nr_sectors
Replace bd_set_size with a version that takes the number of sectors
instead, as that fits most of the current and future callers much better.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:25 -06:00
Linus Torvalds 4d41ead6ea block-5.9-2020-08-28
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl9JYHoQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpjMMD/9pp/oWPRv2pRXf7JBdQUh7zznIg84Uzv6c
 6Bkfq3eGRk/Rvv21kqbI5gZOnp3/se4M3DNBph89/6Q3idlHAot9UCIAVtsQ2+I6
 p/kNKMMkzIguxP0B6pb9aQTjuvSxUOuxNgGVDU8akPktjDj7Gv/gxIQVchAHqXob
 GL1vpBK/fvjiDHrXCCFVldCsm98P3FT7DzRvXkGXVW7Hg5KHuUVgCZtzeDMaB/dx
 YeGenGm5ZCOLvM1N+jgmF89XSqUmrWlZz8iqFVGJfHRf0G0QwDc2mpdNusnZdXDr
 sf1oG+uXszTTcK/w7/MPaHJyj6s7cKJOsXEnNUjU4VloOZvuemk3W8+t5qQ/+S/C
 usPuUa+QhiqoDLa7YyYgNSO6lx70s+S58TLAEgRbU7SHq/g8huOBQ3YT0MYuhX9C
 ZVGZfa2Yb+zWoQVFPqJcClCNjqzLihSo4qZnGSXiY7aDYM088mzLWnnFLkQ+axUq
 lecWHGOkF5ComTePQV31YCHx9uPtRZzyRJ+bENbFIcQc/CztpARGbADAaphZjSmV
 LXqHJyyNHlIo5IVITQm/qbdU9SdWS8bGNoYkB9Fa53sSWt6NIRfvXyWPE1OuyJ7C
 ICaXyMvo+pM5nXo28BnPwO30tfN5byqnvb7P0g3l7j3Ej/ujkhGPmWDyvj27cnve
 nrKgMZ9bXw==
 =UytK
 -----END PGP SIGNATURE-----

Merge tag 'block-5.9-2020-08-28' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - nbd timeout fix (Hou)

 - device size fix for loop LOOP_CONFIGURE (Martijn)

 - MD pull from Song with raid5 stripe size fix (Yufen)

* tag 'block-5.9-2020-08-28' of git://git.kernel.dk/linux-block:
  md/raid5: make sure stripe_size as power of two
  loop: Set correct device size when using LOOP_CONFIGURE
  nbd: restore default timeout when setting it to zero
2020-08-28 16:38:29 -07:00
Martijn Coenen 79e5dc59e2 loop: Set correct device size when using LOOP_CONFIGURE
The device size calculation was done before processing the loop
configuration, which meant that the we set the size on the underlying
block device incorrectly in case lo_offset/lo_sizelimit were set in the
configuration. Delay computing the size until we've setup the device
parameters correctly.

Fixes: 3448914e8cc5("loop: Add LOOP_CONFIGURE ioctl")
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Tested-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-26 09:30:31 -06:00