linux-stable.git/drivers/block/loop.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

loop: fix ioctl calls using compat_loop_info

2022-04-08T11:58:55+00:00

commit f941c51eeac7ebe0f8ec30943bf78e7f60aad039 upstream.

Support for cryptoloop was deleted in commit 47e9624616c8 ("block:
remove support for cryptoloop and the xor transfer"), making the usage
of loop_info->lo_encrypt_type obsolete. However, this member was also
removed from the compat_loop_info definition and this breaks userspace
ioctl calls for 32-bit binaries and CONFIG_COMPAT=y.

This patch restores the compat_loop_info->lo_encrypt_type member and
marks it obsolete as well as in the uapi header definitions.

Fixes: 47e9624616c8 ("block: remove support for cryptoloop and the xor transfer")
Signed-off-by: Carlos Llamas 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220329201815.1347500-1-cmllamas@google.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: use sysfs_emit() in the sysfs xxx show()

2022-04-08T11:58:37+00:00

[ Upstream commit b27824d31f09ea7b4a6ba2c1b18bd328df3e8bed ]

sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.

Use a generic sysfs_emit function that knows the size of the
temporary buffer and ensures that no overrun is done for offset
attribute in
loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Himanshu Madhani 
Link: https://lore.kernel.org/r/20220215213310.7264-2-kch@nvidia.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: loop:use kstatfs.f_bsize of backing file to set discard granularity

2022-02-11T22:10:49+00:00

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 
Cc: Vivek Goyal 
Reported-by: Pei Zhang 
Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220126035830.296465-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

loop: revert "make autoclear operation asynchronous"

2022-02-11T12:51:23+00:00

The kernel test robot is reporting that xfstest which does

  umount ext2 on xfs
  umount xfs

sequence started failing, for commit 322c4293ecc58110 ("loop: make
autoclear operation asynchronous") removed a guarantee that fput() of
backing file is processed before lo_release() from close() returns to
user mode.

And syzbot is reporting that deferring destroy_workqueue() from
__loop_clr_fd() to a WQ context did not help [1]. Revert that commit.

Link: https://syzkaller.appspot.com/bug?extid=831661966588c802aae9 [1]
Reported-by: kernel test robot 
Acked-by: Jan Kara 
Reviewed-by: Christoph Hellwig 
Reported-by: syzbot 
Signed-off-by: Tetsuo Handa 
Link: https://lore.kernel.org/r/20220211071554.3424-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Jens Axboe

loop: remove redundant initialization of pointer node

2022-01-13T20:00:32+00:00

The pointer node is being initialized with a value that is never
read, it is being re-assigned the same value a little futher on.
Remove the redundant initialization. Cleans up clang scan warning:

drivers/block/loop.c:823:19: warning: Value stored to 'node' during
its initialization is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King 
Link: https://lore.kernel.org/r/20220113001432.1331871-1-colin.i.king@gmail.com
Signed-off-by: Jens Axboe

Merge tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-block

2022-01-12T18:35:23+00:00

Pull block driver updates from Jens Axboe:

 - mtip32xx pci cleanups (Bjorn)

 - mtip32xx conversion to generic power management (Vaibhav)

 - rsxx pci powermanagement cleanups (Bjorn)

 - Remove the rsxx driver. This hardware never saw much adoption, and
   it's been end of lifed for a while. (Christoph)

 - MD pull request from Song:
      - REQ_NOWAIT support (Vishal Verma)
      - raid6 benchmark optimization (Dirk Müller)
      - Fix for acct bioset (Xiao Ni)
      - Clean up max_queued_requests (Mariusz Tkaczyk)
      - PREEMPT_RT optimization (Davidlohr Bueso)
      - Use default_groups in kobj_type (Greg Kroah-Hartman)

 - Use attribute groups in pktcdvd and rnbd (Greg)

 - NVMe pull request from Christoph:
      - increment request genctr on completion (Keith Busch, Geliang
        Tang)
      - add a 'iopolicy' module parameter (Hannes Reinecke)
      - print out valid arguments when reading from /dev/nvme-fabrics
        (Hannes Reinecke)

 - Use struct_group() in drbd (Kees)

 - null_blk fixes (Ming)

 - Get rid of congestion logic in pktcdvd (Neil)

 - Floppy ejection hang fix (Tasos)

 - Floppy max user request size fix (Xiongwei)

 - Loop locking fix (Tetsuo)

* tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-block: (32 commits)
  md: use default_groups in kobj_type
  md: Move alloc/free acct bioset in to personality
  lib/raid6: Use strict priority ranking for pq gen() benchmarking
  lib/raid6: skip benchmark of non-chosen xor_syndrome functions
  md: fix spelling of "its"
  md: raid456 add nowait support
  md: raid10 add nowait support
  md: raid1 add nowait support
  md: add support for REQ_NOWAIT
  md: drop queue limitation for RAID1 and RAID10
  md/raid5: play nice with PREEMPT_RT
  block/rnbd-clt-sysfs: use default_groups in kobj_type
  pktcdvd: convert to use attribute groups
  block: null_blk: only set set->nr_maps as 3 if active poll_queues is > 0
  nvme: add 'iopolicy' module parameter
  nvme: drop unused variable ctrl in nvme_setup_cmd
  nvme: increment request genctr on completion
  nvme-fabrics: print out valid arguments when reading from /dev/nvme-fabrics
  block: remove the rsxx driver
  rsxx: Drop PCI legacy power management
  ...

Merge tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block

2022-01-12T18:26:52+00:00

Pull block updates from Jens Axboe:

 - Unify where the struct request handling code is located in the blk-mq
   code (Christoph)

 - Header cleanups (Christoph)

 - Clean up the io_context handling code (Christoph, me)

 - Get rid of ->rq_disk in struct request (Christoph)

 - Error handling fix for add_disk() (Christoph)

 - request allocation cleanusp (Christoph)

 - Documentation updates (Eric, Matthew)

 - Remove trivial crypto unregister helper (Eric)

 - Reduce shared tag overhead (John)

 - Reduce poll_stats memory overhead (me)

 - Known indirect function call for dio (me)

 - Use atomic references for struct request (me)

 - Support request list issue for block and NVMe (me)

 - Improve queue dispatch pinning (Ming)

 - Improve the direct list issue code (Keith)

 - BFQ improvements (Jan)

 - Direct completion helper and use it in mmc block (Sebastian)

 - Use raw spinlock for the blktrace code (Wander)

 - fsync error handling fix (Ye)

 - Various fixes and cleanups (Lukas, Randy, Yang, Tetsuo, Ming, me)

* tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block: (132 commits)
  MAINTAINERS: add entries for block layer documentation
  docs: block: remove queue-sysfs.rst
  docs: sysfs-block: document virt_boundary_mask
  docs: sysfs-block: document stable_writes
  docs: sysfs-block: fill in missing documentation from queue-sysfs.rst
  docs: sysfs-block: add contact for nomerges
  docs: sysfs-block: sort alphabetically
  docs: sysfs-block: move to stable directory
  block: don't protect submit_bio_checks by q_usage_counter
  block: fix old-style declaration
  nvme-pci: fix queue_rqs list splitting
  block: introduce rq_list_move
  block: introduce rq_list_for_each_safe macro
  block: move rq_list macros to blk-mq.h
  block: drop needless assignment in set_task_ioprio()
  block: remove unnecessary trailing '\'
  bio.h: fix kernel-doc warnings
  block: check minor range in device_add_disk()
  block: use "unsigned long" for blk_validate_block_size().
  block: fix error unwinding in device_add_disk
  ...

loop: make autoclear operation asynchronous

2021-12-13T18:37:31+00:00

syzbot is reporting circular locking problem at __loop_clr_fd() [1], for
commit 87579e9b7d8dc36e ("loop: use worker per cgroup instead of kworker")
is calling destroy_workqueue() with disk->open_mutex held.

This circular dependency cannot be broken unless we call __loop_clr_fd()
without holding disk->open_mutex. Therefore, defer __loop_clr_fd() from
lo_release() to a WQ context.

Link: https://syzkaller.appspot.com/bug?extid=643e4ce4b6ad1347d372 [1]
Reported-by: syzbot 
Suggested-by: Christoph Hellwig 
Cc: Jan Kara 
Tested-by: syzbot+643e4ce4b6ad1347d372@syzkaller.appspotmail.com
Signed-off-by: Tetsuo Handa 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/1ed7df28-ebd6-71fb-70e5-1c2972e05ddb@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe

loop: Use pr_warn_once() for loop_control_remove() warning

2021-11-29T13:44:45+00:00

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 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Tetsuo Handa 
Signed-off-by: Jens Axboe