kernel/linux.git/include/linux/blk-mq.h, branch v6.18.21

blk-mq: Document tags_srcu member in blk_mq_tag_set structure

2025-09-09T13:37:05+00:00

Add missing documentation for the tags_srcu member that was introduced to defer freeing of tags page_list to prevent use-after-free when iterating tags. Fixes htmldocs warning: WARNING: include/linux/blk-mq.h:536 struct member 'tags_srcu' not described in 'blk_mq_tag_set' Reported-by: Stephen Rothwell Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

blk-mq: Defer freeing of tags page_list to SRCU callback

2025-09-08T14:05:32+00:00

Tag iterators can race with the freeing of the request pages(tags->page_list), potentially leading to use-after-free issues. Defer the freeing of the page list and the tags structure itself until after an SRCU grace period has passed. This ensures that any concurrent tag iterators have completed before the memory is released. With this way, we can replace the big tags->lock in tags iterator code path with srcu for solving the issue. This is achieved by: - Adding a new `srcu_struct tags_srcu` to `blk_mq_tag_set` to protect tag map iteration. - Adding an `rcu_head` to `struct blk_mq_tags` to be used with `call_srcu`. - Moving the page list freeing logic and the `kfree(tags)` call into a new callback function, `blk_mq_free_tags_callback`. - In `blk_mq_free_tags`, invoking `call_srcu` to schedule the new callback for deferred execution. The read-side protection for the tag iterators will be added in a subsequent patch. Reviewed-by: Hannes Reinecke Reviewed-by: Yu Kuai Signed-off-by: Ming Lei Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

blk-mq: add number of queue calc helper

2025-07-01T16:24:19+00:00

Add two variants of helper functions that calculate the correct number of queues to use. Two variants are needed because some drivers base their maximum number of queues on the possible CPU mask, while others use the online CPU mask. Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Ming Lei Signed-off-by: Daniel Wagner Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20250617-isolcpus-queue-counters-v1-2-13923686b54b@kernel.org Signed-off-by: Jens Axboe

block: remove the q argument from blk_rq_map_kern

2025-05-07T13:31:07+00:00

Remove the q argument from blk_rq_map_kern and the internal helpers called by it as the queue can trivially be derived from the request. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250507120451.4000627-6-hch@lst.de Signed-off-by: Jens Axboe

block: fix warning on 'make htmldocs'

2025-05-07T11:37:39+00:00

Fix the following warning when running 'make htmldocs': +WARNING: include/linux/blk-mq.h:532 struct member 'update_nr_hwq_lock' not described in 'blk_mq_tag_set' Fixes: 98e68f67020c ("block: prevent adding/deleting disk during updating nr_hw_queues") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/all/20250507163220.00141d77@canb.auug.org.au/ Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250507092537.3009112-1-ming.lei@redhat.com Signed-off-by: Jens Axboe

block: prevent adding/deleting disk during updating nr_hw_queues

2025-05-06T13:43:42+00:00

Both adding/deleting disk code are reader of `nr_hw_queues`, so we can't allow them in-progress when updating nr_hw_queues, kernel panic and kasan has been reported in [1]. Prevent adding/deleting disk during updating nr_hw_queues by adding rw_semaphore to tagset, write lock is grabbed in blk_mq_update_nr_hw_queues(), and read lock is acquired when adding/deleting disk. Also mark GFP_NOIO allocation scope for adding/deleting disk because blk_mq_update_nr_hw_queues() is part of some driver's error handler. This way avoids lot of trouble. Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Nilay Shroff Suggested-by: Nilay Shroff Reported-by: Nilay Shroff Closes: https://lore.kernel.org/linux-block/a5896cdb-a59a-4a37-9f99-20522f5d2987@linux.ibm.com/ Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250505141805.2751237-9-ming.lei@redhat.com Signed-off-by: Jens Axboe

Merge tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux

2025-03-27T01:08:55+00:00

Pull block updates from Jens Axboe: - Fixes for integrity handling - NVMe pull request via Keith: - Secure concatenation for TCP transport (Hannes) - Multipath sysfs visibility (Nilay) - Various cleanups (Qasim, Baruch, Wang, Chen, Mike, Damien, Li) - Correct use of 64-bit BARs for pci-epf target (Niklas) - Socket fix for selinux when used in containers (Peijie) - MD pull request via Yu: - fix recovery can preempt resync (Li Nan) - fix md-bitmap IO limit (Su Yue) - fix raid10 discard with REQ_NOWAIT (Xiao Ni) - fix raid1 memory leak (Zheng Qixing) - fix mddev uaf (Yu Kuai) - fix raid1,raid10 IO flags (Yu Kuai) - some refactor and cleanup (Yu Kuai) - Series cleaning up and fixing bugs in the bad block handling code - Improve support for write failure simulation in null_blk - Various lock ordering fixes - Fixes for locking for debugfs attributes - Various ublk related fixes and improvements - Cleanups for blk-rq-qos wait handling - blk-throttle fixes - Fixes for loop dio and sync handling - Fixes and cleanups for the auto-PI code - Block side support for hardware encryption keys in blk-crypto - Various cleanups and fixes * tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux: (105 commits) nvmet: replace max(a, min(b, c)) by clamp(val, lo, hi) nvme-tcp: fix selinux denied when calling sock_sendmsg nvmet: pci-epf: Always configure BAR0 as 64-bit nvmet: Remove duplicate uuid_copy nvme: zns: Simplify nvme_zone_parse_entry() nvmet: pci-epf: Remove redundant 'flush_workqueue()' calls nvmet-fc: Remove unused functions nvme-pci: remove stale comment nvme-fc: Utilise min3() to simplify queue count calculation nvme-multipath: Add visibility for queue-depth io-policy nvme-multipath: Add visibility for numa io-policy nvme-multipath: Add visibility for round-robin io-policy nvmet: add tls_concat and tls_key debugfs entries nvmet-tcp: support secure channel concatenation nvmet: Add 'sq' argument to alloc_ctrl_args nvme-fabrics: reset admin connection for secure concatenation nvme-tcp: request secure channel concatenation nvme-keyring: add nvme_tls_psk_refresh() nvme: add nvme_auth_derive_tls_psk() nvme: add nvme_auth_generate_digest() ...

block: remove unused parameter 'q' parameter in __blk_rq_map_sg()

2025-03-13T11:46:19+00:00

request_queue param is no longer used by blk_rq_map_sg and __blk_rq_map_sg. Remove it. Signed-off-by: Anuj Gupta Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20250313035322.243239-1-anuj20.g@samsung.com Signed-off-by: Jens Axboe

block: change blk_mq_add_to_batch() third argument type to bool

2025-03-12T14:26:36+00:00

Commit 1f47ed294a2b ("block: cleanup and fix batch completion adding conditions") modified the evaluation criteria for the third argument, 'ioerror', in the blk_mq_add_to_batch() function. Initially, the function had checked if 'ioerror' equals zero. Following the commit, it started checking for negative error values, with the presumption that such values, for instance -EIO, would be passed in. However, blk_mq_add_to_batch() callers do not pass negative error values. Instead, they pass status codes defined in various ways: - NVMe PCI and Apple drivers pass NVMe status code - virtio_blk driver passes the virtblk request header status byte - null_blk driver passes blk_status_t These codes are either zero or positive, therefore the revised check fails to function as intended. Specifically, with the NVMe PCI driver, this modification led to the failure of the blktests test case nvme/039. In this test scenario, errors are artificially injected to the NVMe driver, resulting in positive NVMe status codes passed to blk_mq_add_to_batch(), which unexpectedly processes the failed I/O in a batch. Hence the failure. To correct the ioerror check within blk_mq_add_to_batch(), make all callers to uniformly pass the argument as boolean. Modify the callers to check their specific status codes and pass the boolean value 'is_error'. Also describe the arguments of blK_mq_add_to_batch as kerneldoc. Fixes: 1f47ed294a2b ("block: cleanup and fix batch completion adding conditions") Signed-off-by: Shin'ichiro Kawasaki Link: https://lore.kernel.org/r/20250311104359.1767728-3-shinichiro.kawasaki@wdc.com [axboe: fold in documentation update] Signed-off-by: Jens Axboe

block: Name the RQF flags enum

2025-03-07T00:50:55+00:00

Commit 5f89154e8e9e3445f9b59 ("block: Use enum to define RQF_x bit indexes") converted the RQF flags to an anonymous enum, which was a beneficial change. This patch goes one step further by naming the enum as "rqf_flags". This naming enables exporting these flags to BPF clients, eliminating the need to duplicate these flags in BPF code. Instead, BPF clients can now access the same kernel-side values through CO:RE (Compile Once, Run Everywhere), as shown in this example: rqf_stats = bpf_core_enum_value(enum rqf_flags, __RQF_STATS) Suggested-by: Yonghong Song Signed-off-by: Breno Leitao Link: https://lore.kernel.org/r/20250306-rqf_flags-v1-1-bbd64918b406@debian.org Signed-off-by: Jens Axboe