linux/drivers/block/loop.c, branch v5.17

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

2022-02-11T22:10:49Z

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"

2022-02-11T12:51:23Z

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

2022-01-13T20:00:32Z

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

2022-01-12T18:35:23Z

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

2022-01-12T18:26:52Z

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

2021-12-13T18:37:31Z

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

2021-11-29T13:44:45Z

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

loop: don't hold lo_mutex during __loop_clr_fd()

2021-11-29T13:41:47Z

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 lo->lo_mutex held. Since all functions where lo->lo_state matters are already checking lo->lo_state with lo->lo_mutex held (in order to avoid racing with e.g. ioctl(LOOP_CTL_REMOVE)), and __loop_clr_fd() can be called from either ioctl(LOOP_CLR_FD) xor close(), lo->lo_state == Lo_rundown is considered as an exclusive lock for __loop_clr_fd(). Therefore, hold lo->lo_mutex inside __loop_clr_fd() only when asserting/updating lo->lo_state. Since ioctl(LOOP_CLR_FD) depends on lo->lo_state == Lo_bound, a valid lo->lo_backing_file must have been assigned by ioctl(LOOP_SET_FD) or ioctl(LOOP_CONFIGURE). Thus, we can remove lo->lo_backing_file test, and convert __loop_clr_fd() into a void function. Link: https://syzkaller.appspot.com/bug?extid=63614029dfb79abd4383 [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/8ebe3b2e-8975-7f26-0620-7144a3b8b8cd@i-love.sakura.ne.jp Signed-off-by: Jens Axboe

block: remove GENHD_FL_EXT_DEVT

2021-11-29T13:38:35Z

All modern drivers can support extra partitions using the extended dev_t. In fact except for the ioctl method drivers never even see partitions in normal operation. So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all block devices that do support partitions, and require those that do not support partitions to explicit disallow them using GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de Signed-off-by: Jens Axboe

block: rename GENHD_FL_NO_PART_SCAN to GENHD_FL_NO_PART

2021-11-29T13:35:21Z

The GENHD_FL_NO_PART_SCAN controls more than just partitions canning, so rename it to GENHD_FL_NO_PART. Signed-off-by: Christoph Hellwig Acked-by: Ulf Hansson Link: https://lore.kernel.org/r/20211122130625.1136848-7-hch@lst.de Signed-off-by: Jens Axboe