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path: root/drivers/block/null_blk/main.c
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2021-06-30null_blk: remove an unused variable assignment in null_add_devChristoph Hellwig
Fix up the recent blk_alloc_disk conversion. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210614060231.3965278-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-11nullb: use blk_mq_alloc_diskChristoph Hellwig
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/20210602065345.355274-21-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-03null_blk: Fix null pointer dereference on nullb->disk on blk_cleanup_disk callColin Ian King
The error handling on a nullb->disk allocation currently jumps to out_cleanup_disk that calls blk_cleanup_disk with a null pointer causing a null pointer dereference issue. Fix this by jumping to out_cleanup_tags instead. Addresses-Coverity: ("Dereference after null check") Fixes: 132226b301b5 ("null_blk: convert to blk_alloc_disk/blk_cleanup_disk") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210602100659.11058-1-colin.king@canonical.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01null_blk: convert to blk_alloc_disk/blk_cleanup_diskChristoph Hellwig
Convert the null_blk driver to use the blk_alloc_disk and blk_cleanup_disk helpers to simplify gendisk and request_queue allocation. Note that the blk-mq mode is left with its own allocations scheme, to be handled later. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://lore.kernel.org/r/20210521055116.1053587-26-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-28Merge tag 'for-5.13/drivers-2021-04-27' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: - MD changes via Song: - raid5 POWER fix - raid1 failure fix - UAF fix for md cluster - mddev_find_or_alloc() clean up - Fix NULL pointer deref with external bitmap - Performance improvement for raid10 discard requests - Fix missing information of /proc/mdstat - rsxx const qualifier removal (Arnd) - Expose allocated brd pages (Calvin) - rnbd via Gioh Kim: - Change maintainer - Change domain address of maintainers' email - Add polling IO mode and document update - Fix memory leak and some bug detected by static code analysis tools - Code refactoring - Series of floppy cleanups/fixes (Denis) - s390 dasd fixes (Julian) - kerneldoc fixes (Lee) - null_blk double free (Lv) - null_blk virtual boundary addition (Max) - Remove xsysace driver (Michal) - umem driver removal (Davidlohr) - ataflop fixes (Dan) - Revalidate disk removal (Christoph) - Bounce buffer cleanups (Christoph) - Mark lightnvm as deprecated (Christoph) - mtip32xx init cleanups (Shixin) - Various fixes (Tian, Gustavo, Coly, Yang, Zhang, Zhiqiang) * tag 'for-5.13/drivers-2021-04-27' of git://git.kernel.dk/linux-block: (143 commits) async_xor: increase src_offs when dropping destination page drivers/block/null_blk/main: Fix a double free in null_init. md/raid1: properly indicate failure when ending a failed write request md-cluster: fix use-after-free issue when removing rdev nvme: introduce generic per-namespace chardev nvme: cleanup nvme_configure_apst nvme: do not try to reconfigure APST when the controller is not live nvme: add 'kato' sysfs attribute nvme: sanitize KATO setting nvmet: avoid queuing keep-alive timer if it is disabled brd: expose number of allocated pages in debugfs ataflop: fix off by one in ataflop_probe() ataflop: potential out of bounds in do_format() drbd: Fix fall-through warnings for Clang block/rnbd: Use strscpy instead of strlcpy block/rnbd-clt-sysfs: Remove copy buffer overlap in rnbd_clt_get_path_name block/rnbd-clt: Remove max_segment_size block/rnbd-clt: Generate kobject_uevent when the rnbd device state changes block/rnbd-srv: Remove unused arguments of rnbd_srv_rdma_ev Documentation/ABI/rnbd-clt: Add description for nr_poll_queues ...
2021-04-12null_blk: add option for managing virtual boundaryMax Gurtovoy
This will enable changing the virtual boundary of null blk devices. For now, null blk devices didn't have any restriction on the scatter/gather elements received from the block layer. Add a module parameter and a configfs option that will control the virtual boundary. This will enable testing the efficiency of the block layer bounce buffer in case a suitable application will send discontiguous IO to the given device. Initial testing with patched FIO showed the following results (64 jobs, 128 iodepth, 1 nullb device): IO size READ (virt=false) READ (virt=true) Write (virt=false) Write (virt=true) ---------- ------------------- ----------------- ------------------- ------------------- 1k 10.7M 8482k 10.8M 8471k 2k 10.4M 8266k 10.4M 8271k 4k 10.4M 8274k 10.3M 8226k 8k 10.2M 8131k 9800k 7933k 16k 9567k 7764k 8081k 6828k 32k 8865k 7309k 5570k 5153k 64k 7695k 6586k 2682k 2617k 128k 5346k 5489k 1320k 1296k Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210412095523.278632-1-mgurtovoy@nvidia.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-01null_blk: fix command timeout completion handlingDamien Le Moal
Memory backed or zoned null block devices may generate actual request timeout errors due to the submission path being blocked on memory allocation or zone locking. Unlike fake timeouts or injected timeouts, the request submission path will call blk_mq_complete_request() or blk_mq_end_request() for these real timeout errors, causing a double completion and use after free situation as the block layer timeout handler executes blk_mq_rq_timed_out() and __blk_mq_free_request() in blk_mq_check_expired(). This problem often triggers a NULL pointer dereference such as: BUG: kernel NULL pointer dereference, address: 0000000000000050 RIP: 0010:blk_mq_sched_mark_restart_hctx+0x5/0x20 ... Call Trace: dd_finish_request+0x56/0x80 blk_mq_free_request+0x37/0x130 null_handle_cmd+0xbf/0x250 [null_blk] ? null_queue_rq+0x67/0xd0 [null_blk] blk_mq_dispatch_rq_list+0x122/0x850 __blk_mq_do_dispatch_sched+0xbb/0x2c0 __blk_mq_sched_dispatch_requests+0x13d/0x190 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x49/0x90 process_one_work+0x26c/0x580 worker_thread+0x55/0x3c0 ? process_one_work+0x580/0x580 kthread+0x134/0x150 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x1f/0x30 This problem very often triggers when running the full btrfs xfstests on a memory-backed zoned null block device in a VM with limited amount of memory. Avoid this by executing blk_mq_complete_request() in null_timeout_rq() only for commands that are marked for a fake timeout completion using the fake_timeout boolean in struct null_cmd. For timeout errors injected through debugfs, the timeout handler will execute blk_mq_complete_request()i as before. This is safe as the submission path does not execute complete requests in this case. In null_timeout_rq(), also make sure to set the command error field to BLK_STS_TIMEOUT and to propagate this error through to the request completion. Reported-by: Johannes Thumshirn <Johannes.Thumshirn@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Tested-by: Johannes Thumshirn <Johannes.Thumshirn@wdc.com> Reviewed-by: Johannes Thumshirn <Johannes.Thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210331225244.126426-1-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24block: store a block_device pointer in struct bioChristoph Hellwig
Replace the gendisk pointer in struct bio with a pointer to the newly improved struct block device. From that the gendisk can be trivially accessed with an extra indirection, but it also allows to directly look up all information related to partition remapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-07null_blk: Move driver into its own directoryDamien Le Moal
Move null_blk driver code into the new sub-directory drivers/block/null_blk. Suggested-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>