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2024-12-18block: Revert "block: Fix potential deadlock while freezing queue and ↵Ming Lei
acquiring sysfs_lock" This reverts commit be26ba96421ab0a8fa2055ccf7db7832a13c44d2. Commit be26ba96421a ("block: Fix potential deadlock while freezing queue and acquiring sysfs_loc") actually reverts commit 22465bbac53c ("blk-mq: move cpuhp callback registering out of q->sysfs_lock"), and causes the original resctrl lockdep warning. So revert it and we need to fix the issue in another way. Cc: Nilay Shroff <nilay@linux.ibm.com> Fixes: be26ba96421a ("block: Fix potential deadlock while freezing queue and acquiring sysfs_loc") Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20241218101617.3275704-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-13block: Fix potential deadlock while freezing queue and acquiring sysfs_lockNilay Shroff
For storing a value to a queue attribute, the queue_attr_store function first freezes the queue (->q_usage_counter(io)) and then acquire ->sysfs_lock. This seems not correct as the usual ordering should be to acquire ->sysfs_lock before freezing the queue. This incorrect ordering causes the following lockdep splat which we are able to reproduce always simply by accessing /sys/kernel/debug file using ls command: [ 57.597146] WARNING: possible circular locking dependency detected [ 57.597154] 6.12.0-10553-gb86545e02e8c #20 Tainted: G W [ 57.597162] ------------------------------------------------------ [ 57.597168] ls/4605 is trying to acquire lock: [ 57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0 [ 57.597200] but task is already holding lock: [ 57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4 [ 57.597226] which lock already depends on the new lock. [ 57.597233] the existing dependency chain (in reverse order) is: [ 57.597241] -> #5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}: [ 57.597255] down_write+0x6c/0x18c [ 57.597264] start_creating+0xb4/0x24c [ 57.597274] debugfs_create_dir+0x2c/0x1e8 [ 57.597283] blk_register_queue+0xec/0x294 [ 57.597292] add_disk_fwnode+0x2e4/0x548 [ 57.597302] brd_alloc+0x2c8/0x338 [ 57.597309] brd_init+0x100/0x178 [ 57.597317] do_one_initcall+0x88/0x3e4 [ 57.597326] kernel_init_freeable+0x3cc/0x6e0 [ 57.597334] kernel_init+0x34/0x1cc [ 57.597342] ret_from_kernel_user_thread+0x14/0x1c [ 57.597350] -> #4 (&q->debugfs_mutex){+.+.}-{4:4}: [ 57.597362] __mutex_lock+0xfc/0x12a0 [ 57.597370] blk_register_queue+0xd4/0x294 [ 57.597379] add_disk_fwnode+0x2e4/0x548 [ 57.597388] brd_alloc+0x2c8/0x338 [ 57.597395] brd_init+0x100/0x178 [ 57.597402] do_one_initcall+0x88/0x3e4 [ 57.597410] kernel_init_freeable+0x3cc/0x6e0 [ 57.597418] kernel_init+0x34/0x1cc [ 57.597426] ret_from_kernel_user_thread+0x14/0x1c [ 57.597434] -> #3 (&q->sysfs_lock){+.+.}-{4:4}: [ 57.597446] __mutex_lock+0xfc/0x12a0 [ 57.597454] queue_attr_store+0x9c/0x110 [ 57.597462] sysfs_kf_write+0x70/0xb0 [ 57.597471] kernfs_fop_write_iter+0x1b0/0x2ac [ 57.597480] vfs_write+0x3dc/0x6e8 [ 57.597488] ksys_write+0x84/0x140 [ 57.597495] system_call_exception+0x130/0x360 [ 57.597504] system_call_common+0x160/0x2c4 [ 57.597516] -> #2 (&q->q_usage_counter(io)#21){++++}-{0:0}: [ 57.597530] __submit_bio+0x5ec/0x828 [ 57.597538] submit_bio_noacct_nocheck+0x1e4/0x4f0 [ 57.597547] iomap_readahead+0x2a0/0x448 [ 57.597556] xfs_vm_readahead+0x28/0x3c [ 57.597564] read_pages+0x88/0x41c [ 57.597571] page_cache_ra_unbounded+0x1ac/0x2d8 [ 57.597580] filemap_get_pages+0x188/0x984 [ 57.597588] filemap_read+0x13c/0x4bc [ 57.597596] xfs_file_buffered_read+0x88/0x17c [ 57.597605] xfs_file_read_iter+0xac/0x158 [ 57.597614] vfs_read+0x2d4/0x3b4 [ 57.597622] ksys_read+0x84/0x144 [ 57.597629] system_call_exception+0x130/0x360 [ 57.597637] system_call_common+0x160/0x2c4 [ 57.597647] -> #1 (mapping.invalidate_lock#2){++++}-{4:4}: [ 57.597661] down_read+0x6c/0x220 [ 57.597669] filemap_fault+0x870/0x100c [ 57.597677] xfs_filemap_fault+0xc4/0x18c [ 57.597684] __do_fault+0x64/0x164 [ 57.597693] __handle_mm_fault+0x1274/0x1dac [ 57.597702] handle_mm_fault+0x248/0x484 [ 57.597711] ___do_page_fault+0x428/0xc0c [ 57.597719] hash__do_page_fault+0x30/0x68 [ 57.597727] do_hash_fault+0x90/0x35c [ 57.597736] data_access_common_virt+0x210/0x220 [ 57.597745] _copy_from_user+0xf8/0x19c [ 57.597754] sel_write_load+0x178/0xd54 [ 57.597762] vfs_write+0x108/0x6e8 [ 57.597769] ksys_write+0x84/0x140 [ 57.597777] system_call_exception+0x130/0x360 [ 57.597785] system_call_common+0x160/0x2c4 [ 57.597794] -> #0 (&mm->mmap_lock){++++}-{4:4}: [ 57.597806] __lock_acquire+0x17cc/0x2330 [ 57.597814] lock_acquire+0x138/0x400 [ 57.597822] __might_fault+0x7c/0xc0 [ 57.597830] filldir64+0xe8/0x390 [ 57.597839] dcache_readdir+0x80/0x2d4 [ 57.597846] iterate_dir+0xd8/0x1d4 [ 57.597855] sys_getdents64+0x88/0x2d4 [ 57.597864] system_call_exception+0x130/0x360 [ 57.597872] system_call_common+0x160/0x2c4 [ 57.597881] other info that might help us debug this: [ 57.597888] Chain exists of: &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3 [ 57.597905] Possible unsafe locking scenario: [ 57.597911] CPU0 CPU1 [ 57.597917] ---- ---- [ 57.597922] rlock(&sb->s_type->i_mutex_key#3); [ 57.597932] lock(&q->debugfs_mutex); [ 57.597940] lock(&sb->s_type->i_mutex_key#3); [ 57.597950] rlock(&mm->mmap_lock); [ 57.597958] *** DEADLOCK *** [ 57.597965] 2 locks held by ls/4605: [ 57.597971] #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154 [ 57.597989] #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4 Prevent the above lockdep warning by acquiring ->sysfs_lock before freezing the queue while storing a queue attribute in queue_attr_store function. Later, we also found[1] another function __blk_mq_update_nr_ hw_queues where we first freeze queue and then acquire the ->sysfs_lock. So we've also updated lock ordering in __blk_mq_update_nr_hw_queues function and ensured that in all code paths we follow the correct lock ordering i.e. acquire ->sysfs_lock before freezing the queue. [1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/ Reported-by: kjain@linux.ibm.com Fixes: af2814149883 ("block: freeze the queue in queue_attr_store") Tested-by: kjain@linux.ibm.com Cc: hch@lst.de Cc: axboe@kernel.dk Cc: ritesh.list@gmail.com Cc: ming.lei@redhat.com Cc: gjoyce@linux.ibm.com Signed-off-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20241210144222.1066229-1-nilay@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-13block: Fix queue_iostats_passthrough_show()Bart Van Assche
Make queue_iostats_passthrough_show() report 0/1 in sysfs instead of 0/4. This patch fixes the following sparse warning: block/blk-sysfs.c:266:31: warning: incorrect type in argument 1 (different base types) block/blk-sysfs.c:266:31: expected unsigned long var block/blk-sysfs.c:266:31: got restricted blk_flags_t Cc: Keith Busch <kbusch@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Fixes: 110234da18ab ("block: enable passthrough command statistics") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20241212212941.1268662-4-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-18block: fix uaf for flush rq while iterating tagsYu Kuai
blk_mq_clear_flush_rq_mapping() is not called during scsi probe, by checking blk_queue_init_done(). However, QUEUE_FLAG_INIT_DONE is cleared in del_gendisk by commit aec89dc5d421 ("block: keep q_usage_counter in atomic mode after del_gendisk"), hence for disk like scsi, following blk_mq_destroy_queue() will not clear flush rq from tags->rqs[] as well, cause following uaf that is found by our syzkaller for v6.6: ================================================================== BUG: KASAN: slab-use-after-free in blk_mq_find_and_get_req+0x16e/0x1a0 block/blk-mq-tag.c:261 Read of size 4 at addr ffff88811c969c20 by task kworker/1:2H/224909 CPU: 1 PID: 224909 Comm: kworker/1:2H Not tainted 6.6.0-ga836a5060850 #32 Workqueue: kblockd blk_mq_timeout_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106 print_address_description.constprop.0+0x66/0x300 mm/kasan/report.c:364 print_report+0x3e/0x70 mm/kasan/report.c:475 kasan_report+0xb8/0xf0 mm/kasan/report.c:588 blk_mq_find_and_get_req+0x16e/0x1a0 block/blk-mq-tag.c:261 bt_iter block/blk-mq-tag.c:288 [inline] __sbitmap_for_each_set include/linux/sbitmap.h:295 [inline] sbitmap_for_each_set include/linux/sbitmap.h:316 [inline] bt_for_each+0x455/0x790 block/blk-mq-tag.c:325 blk_mq_queue_tag_busy_iter+0x320/0x740 block/blk-mq-tag.c:534 blk_mq_timeout_work+0x1a3/0x7b0 block/blk-mq.c:1673 process_one_work+0x7c4/0x1450 kernel/workqueue.c:2631 process_scheduled_works kernel/workqueue.c:2704 [inline] worker_thread+0x804/0xe40 kernel/workqueue.c:2785 kthread+0x346/0x450 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:293 Allocated by task 942: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc mm/kasan/common.c:383 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:380 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node+0x69/0x170 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kzalloc_node include/linux/slab.h:732 [inline] blk_alloc_flush_queue+0x144/0x2f0 block/blk-flush.c:499 blk_mq_alloc_hctx+0x601/0x940 block/blk-mq.c:3788 blk_mq_alloc_and_init_hctx+0x27f/0x330 block/blk-mq.c:4261 blk_mq_realloc_hw_ctxs+0x488/0x5e0 block/blk-mq.c:4294 blk_mq_init_allocated_queue+0x188/0x860 block/blk-mq.c:4350 blk_mq_init_queue_data block/blk-mq.c:4166 [inline] blk_mq_init_queue+0x8d/0x100 block/blk-mq.c:4176 scsi_alloc_sdev+0x843/0xd50 drivers/scsi/scsi_scan.c:335 scsi_probe_and_add_lun+0x77c/0xde0 drivers/scsi/scsi_scan.c:1189 __scsi_scan_target+0x1fc/0x5a0 drivers/scsi/scsi_scan.c:1727 scsi_scan_channel drivers/scsi/scsi_scan.c:1815 [inline] scsi_scan_channel+0x14b/0x1e0 drivers/scsi/scsi_scan.c:1791 scsi_scan_host_selected+0x2fe/0x400 drivers/scsi/scsi_scan.c:1844 scsi_scan+0x3a0/0x3f0 drivers/scsi/scsi_sysfs.c:151 store_scan+0x2a/0x60 drivers/scsi/scsi_sysfs.c:191 dev_attr_store+0x5c/0x90 drivers/base/core.c:2388 sysfs_kf_write+0x11c/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x3fc/0x610 fs/kernfs/file.c:338 call_write_iter include/linux/fs.h:2083 [inline] new_sync_write+0x1b4/0x2d0 fs/read_write.c:493 vfs_write+0x76c/0xb00 fs/read_write.c:586 ksys_write+0x127/0x250 fs/read_write.c:639 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x78/0xe2 Freed by task 244687: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x50 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] __kasan_slab_free+0x12a/0x1b0 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1815 [inline] slab_free_freelist_hook mm/slub.c:1841 [inline] slab_free mm/slub.c:3807 [inline] __kmem_cache_free+0xe4/0x520 mm/slub.c:3820 blk_free_flush_queue+0x40/0x60 block/blk-flush.c:520 blk_mq_hw_sysfs_release+0x4a/0x170 block/blk-mq-sysfs.c:37 kobject_cleanup+0x136/0x410 lib/kobject.c:689 kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x119/0x140 lib/kobject.c:737 blk_mq_release+0x24f/0x3f0 block/blk-mq.c:4144 blk_free_queue block/blk-core.c:298 [inline] blk_put_queue+0xe2/0x180 block/blk-core.c:314 blkg_free_workfn+0x376/0x6e0 block/blk-cgroup.c:144 process_one_work+0x7c4/0x1450 kernel/workqueue.c:2631 process_scheduled_works kernel/workqueue.c:2704 [inline] worker_thread+0x804/0xe40 kernel/workqueue.c:2785 kthread+0x346/0x450 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:293 Other than blk_mq_clear_flush_rq_mapping(), the flag is only used in blk_register_queue() from initialization path, hence it's safe not to clear the flag in del_gendisk. And since QUEUE_FLAG_REGISTERED already make sure that queue should only be registered once, there is no need to test the flag as well. Fixes: 6cfeadbff3f8 ("blk-mq: don't clear flush_rq from tags->rqs[]") Depends-on: commit aec89dc5d421 ("block: keep q_usage_counter in atomic mode after del_gendisk") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20241104110005.1412161-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-11block: pre-calculate max_zone_append_sectorsChristoph Hellwig
max_zone_append_sectors differs from all other queue limits in that the final value used is not stored in the queue_limits but needs to be obtained using queue_limits_max_zone_append_sectors helper. This not only adds (tiny) extra overhead to the I/O path, but also can be easily forgotten in file system code. Add a new max_hw_zone_append_sectors value to queue_limits which is set by the driver, and calculate max_zone_append_sectors from that and the other inputs in blk_validate_zoned_limits, similar to how max_sectors is calculated to fix this. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20241108154657.845768-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-07block: Replace sprintf() with sysfs_emit()zhangguopeng
Per Documentation/filesystems/sysfs.rst, show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. No functional change intended. Signed-off-by: zhangguopeng <zhangguopeng@kylinos.cn> Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241107104258.29742-1-zhangguopeng@kylinos.cn Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-07Revert "block: pre-calculate max_zone_append_sectors"Jens Axboe
This causes issue on, at least, nvme-mpath where my boot fails with: WARNING: CPU: 354 PID: 2729 at block/blk-settings.c:75 blk_validate_limits+0x356/0x380 Modules linked in: tg3(+) nvme usbcore scsi_mod ptp i2c_piix4 libphy nvme_core crc32c_intel scsi_common usb_common pps_core i2c_smbus CPU: 354 UID: 0 PID: 2729 Comm: kworker/u2061:1 Not tainted 6.12.0-rc6+ #181 Hardware name: Dell Inc. PowerEdge R7625/06444F, BIOS 1.8.3 04/02/2024 Workqueue: async async_run_entry_fn RIP: 0010:blk_validate_limits+0x356/0x380 Code: f6 47 01 04 75 28 83 bf 94 00 00 00 00 75 39 83 bf 98 00 00 00 00 75 34 83 7f 68 00 75 32 31 c0 83 7f 5c 00 0f 84 9b fd ff ff <0f> 0b eb 13 0f 0b eb 0f 48 c7 c0 74 12 58 92 48 89 c7 e8 13 76 46 RSP: 0018:ffffa8a1dfb93b30 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff9232829c8388 RCX: 0000000000000088 RDX: 0000000000000080 RSI: 0000000000000200 RDI: ffffa8a1dfb93c38 RBP: 000000000000000c R08: 00000000ffffffff R09: 000000000000ffff R10: 0000000000000000 R11: 0000000000000000 R12: ffff9232829b9000 R13: ffff9232829b9010 R14: ffffa8a1dfb93c38 R15: ffffa8a1dfb93c38 FS: 0000000000000000(0000) GS:ffff923867c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c1b92480a8 CR3: 0000002484ff0002 CR4: 0000000000370ef0 Call Trace: <TASK> ? __warn+0xca/0x1a0 ? blk_validate_limits+0x356/0x380 ? report_bug+0x11a/0x1a0 ? handle_bug+0x5e/0x90 ? exc_invalid_op+0x16/0x40 ? asm_exc_invalid_op+0x16/0x20 ? blk_validate_limits+0x356/0x380 blk_alloc_queue+0x7a/0x250 __blk_alloc_disk+0x39/0x80 nvme_mpath_alloc_disk+0x13d/0x1b0 [nvme_core] nvme_scan_ns+0xcc7/0x1010 [nvme_core] async_run_entry_fn+0x27/0x120 process_scheduled_works+0x1a0/0x360 worker_thread+0x2bc/0x350 ? pr_cont_work+0x1b0/0x1b0 kthread+0x111/0x120 ? kthread_unuse_mm+0x90/0x90 ret_from_fork+0x30/0x40 ? kthread_unuse_mm+0x90/0x90 ret_from_fork_asm+0x11/0x20 </TASK> ---[ end trace 0000000000000000 ]--- presumably due to max_zone_append_sectors not being cleared to zero, resulting in blk_validate_zoned_limits() complaining and failing. This reverts commit 2a8f6153e1c2db06a537a5c9d61102eb591776f1. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-04block: pre-calculate max_zone_append_sectorsChristoph Hellwig
max_zone_append_sectors differs from all other queue limits in that the final value used is not stored in the queue_limits but needs to be obtained using queue_limits_max_zone_append_sectors helper. This not only adds (tiny) extra overhead to the I/O path, but also can be easily forgotten in file system code. Add a new max_hw_zone_append_sectors value to queue_limits which is set by the driver, and calculate max_zone_append_sectors from that and the other inputs in blk_validate_zoned_limits, similar to how max_sectors is calculated to fix this. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-22block: enable passthrough command statisticsKeith Busch
Applications using the passthrough interfaces for IO want to continue seeing the disk stats. These requests had been fenced off from this block layer feature. While the block layer doesn't necessarily know what a passthrough command does, we do know the data size and direction, which is enough to account for the command's stats. Since tracking these has the potential to produce unexpected results, the passthrough stats are locked behind a new queue flag that needs to be enabled with the /sys/block/<dev>/queue/iostats_passthrough attribute. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241007153236.2818562-1-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-22block: return void from the queue_sysfs_entry load_module methodChristoph Hellwig
Requesting a module either succeeds or does nothing, return an error from this method does not make sense. Also move the load_module after the store method in the struct declaration to keep the important show and store methods together. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20241008050841.104602-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10block: Prevent deadlocks when switching elevatorsDamien Le Moal
Commit af2814149883 ("block: freeze the queue in queue_attr_store") changed queue_attr_store() to always freeze a sysfs attribute queue before calling the attribute store() method, to ensure that no IOs are in-flight when an attribute value is being updated. However, this change created a potential deadlock situation for the scheduler queue attribute as changing the queue elevator with elv_iosched_store() can result in a call to request_module() if the user requested module is not already registered. If the file of the requested module is stored on the block device of the frozen queue, a deadlock will happen as the read operations triggered by request_module() will wait for the queue freeze to end. Solve this issue by introducing the load_module method in struct queue_sysfs_entry, and to calling this method function in queue_attr_store() before freezing the attribute queue. The macro definition QUEUE_RW_LOAD_MODULE_ENTRY() is added to define a queue sysfs attribute that needs loading a module. The definition of the scheduler atrribute is changed to using QUEUE_RW_LOAD_MODULE_ENTRY(), with the function elv_iosched_load_module() defined as the load_module method. elv_iosched_store() can then be simplified to remove the call to request_module(). Reported-by: Richard W.M. Jones <rjones@redhat.com> Reported-by: Jiri Jaburek <jjaburek@redhat.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219166 Fixes: af2814149883 ("block: freeze the queue in queue_attr_store") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Tested-by: Richard W.M. Jones <rjones@redhat.com> Link: https://lore.kernel.org/r/20240908000704.414538-1-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-28block: pass a gendisk to the queue_sysfs_entry methodsChristoph Hellwig
The kobject for the queue entries is embedded into a struct gendisk. Pass it to the sysfs methods instead of the request_queue derived from it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20240627111407.476276-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-28block: add helper macros to de-duplicate the queue sysfs attributesChristoph Hellwig
A lof the code to implement the queue sysfs attributes is repetitive. Add a few macros to generate the common cases. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20240627111407.476276-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26block: convert features and flags to __bitwise typesChristoph Hellwig
... and let sparse help us catch mismatches or abuses. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240626142637.300624-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26block: correctly report cache typeChristoph Hellwig
Check the features flag and the override flag using the blk_queue_write_cache, helper otherwise we're going to always report "write through". Fixes: 1122c0c1cc71 ("block: move cache control settings out of queue->flags") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20240626142637.300624-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20block: Add core atomic write supportJohn Garry
Add atomic write support, as follows: - add helper functions to get request_queue atomic write limits - report request_queue atomic write support limits to sysfs and update Doc - support to safely merge atomic writes - deal with splitting atomic writes - misc helper functions - add a per-request atomic write flag New request_queue limits are added, as follows: - atomic_write_hw_max is set by the block driver and is the maximum length of an atomic write which the device may support. It is not necessarily a power-of-2. - atomic_write_max_sectors is derived from atomic_write_hw_max_sectors and max_hw_sectors. It is always a power-of-2. Atomic writes may be merged, and atomic_write_max_sectors would be the limit on a merged atomic write request size. This value is not capped at max_sectors, as the value in max_sectors can be controlled from userspace, and it would only cause trouble if userspace could limit atomic_write_unit_max_bytes and the other atomic write limits. - atomic_write_hw_unit_{min,max} are set by the block driver and are the min/max length of an atomic write unit which the device may support. They both must be a power-of-2. Typically atomic_write_hw_unit_max will hold the same value as atomic_write_hw_max. - atomic_write_unit_{min,max} are derived from atomic_write_hw_unit_{min,max}, max_hw_sectors, and block core limits. Both min and max values must be a power-of-2. - atomic_write_hw_boundary is set by the block driver. If non-zero, it indicates an LBA space boundary at which an atomic write straddles no longer is atomically executed by the disk. The value must be a power-of-2. Note that it would be acceptable to enforce a rule that atomic_write_hw_boundary_sectors is a multiple of atomic_write_hw_unit_max, but the resultant code would be more complicated. All atomic writes limits are by default set 0 to indicate no atomic write support. Even though it is assumed by Linux that a logical block can always be atomically written, we ignore this as it is not of particular interest. Stacked devices are just not supported either for now. An atomic write must always be submitted to the block driver as part of a single request. As such, only a single BIO must be submitted to the block layer for an atomic write. When a single atomic write BIO is submitted, it cannot be split. As such, atomic_write_unit_{max, min}_bytes are limited by the maximum guaranteed BIO size which will not be required to be split. This max size is calculated by request_queue max segments and the number of bvecs a BIO can fit, BIO_MAX_VECS. Currently we rely on userspace issuing a write with iovcnt=1 for pwritev2() - as such, we can rely on each segment containing PAGE_SIZE of data, apart from the first+last, which each can fit logical block size of data. The first+last will be LBS length/aligned as we rely on direct IO alignment rules also. New sysfs files are added to report the following atomic write limits: - atomic_write_unit_max_bytes - same as atomic_write_unit_max_sectors in bytes - atomic_write_unit_min_bytes - same as atomic_write_unit_min_sectors in bytes - atomic_write_boundary_bytes - same as atomic_write_hw_boundary_sectors in bytes - atomic_write_max_bytes - same as atomic_write_max_sectors in bytes Atomic writes may only be merged with other atomic writes and only under the following conditions: - total resultant request length <= atomic_write_max_bytes - the merged write does not straddle a boundary Helper function bdev_can_atomic_write() is added to indicate whether atomic writes may be issued to a bdev. If a bdev is a partition, the partition start must be aligned with both atomic_write_unit_min_sectors and atomic_write_hw_boundary_sectors. FSes will rely on the block layer to validate that an atomic write BIO submitted will be of valid size, so add blk_validate_atomic_write_op_size() for this purpose. Userspace expects an atomic write which is of invalid size to be rejected with -EINVAL, so add BLK_STS_INVAL for this. Also use BLK_STS_INVAL for when a BIO needs to be split, as this should mean an invalid size BIO. Flag REQ_ATOMIC is used for indicating an atomic write. Co-developed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20240620125359.2684798-6-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20block: renumber and rename the cache disabled flagChristoph Hellwig
Start with the first bit, and drop the plural-S from the name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20240619154623.450048-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move the poll flag to queue_limitsChristoph Hellwig
Move the poll flag into the queue_limits feature field so that it can be set atomically with the queue frozen. Stacking drivers are simplified in that they now can simply set the flag, and blk_stack_limits will clear it when the features is not supported by any of the underlying devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-22-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move the stable_writes flag to queue_limitsChristoph Hellwig
Move the stable_writes flag into the queue_limits feature field so that it can be set atomically with the queue frozen. The flag is now inherited by blk_stack_limits, which greatly simplifies the code in dm, and fixed md which previously did not pass on the flag set on lower devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-18-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move the io_stat flag setting to queue_limitsChristoph Hellwig
Move the io_stat flag into the queue_limits feature field so that it can be set atomically with the queue frozen. Simplify md and dm to set the flag unconditionally instead of avoiding setting a simple flag for cases where it already is set by other means, which is a bit pointless. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-17-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move the add_random flag to queue_limitsChristoph Hellwig
Move the add_random flag into the queue_limits feature field so that it can be set atomically with the queue frozen. Note that this also removes code from dm to clear the flag based on the underlying devices, which can't be reached as dm devices will always start out without the flag set. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move the nonrot flag to queue_limitsChristoph Hellwig
Move the nonrot flag into the queue_limits feature field so that it can be set atomically with the queue frozen. Use the chance to switch to defaulting to non-rotational and require the driver to opt into rotational, which matches the polarity of the sysfs interface. For the z2ram, ps3vram, 2x memstick, ubiblock and dcssblk the new rotational flag is not set as they clearly are not rotational despite this being a behavior change. There are some other drivers that unconditionally set the rotational flag to keep the existing behavior as they arguably can be used on rotational devices even if that is probably not their main use today (e.g. virtio_blk and drbd). The flag is automatically inherited in blk_stack_limits matching the existing behavior in dm and md. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move cache control settings out of queue->flagsChristoph Hellwig
Move the cache control settings into the queue_limits so that the flags can be set atomically with the device queue frozen. Add new features and flags field for the driver set flags, and internal (usually sysfs-controlled) flags in the block layer. Note that we'll eventually remove enough field from queue_limits to bring it back to the previous size. The disable flag is inverted compared to the previous meaning, which means it now survives a rescan, similar to the max_sectors and max_discard_sectors user limits. The FLUSH and FUA flags are now inherited by blk_stack_limits, which simplified the code in dm a lot, but also causes a slight behavior change in that dm-switch and dm-unstripe now advertise a write cache despite setting num_flush_bios to 0. The I/O path will handle this gracefully, but as far as I can tell the lack of num_flush_bios and thus flush support is a pre-existing data integrity bug in those targets that really needs fixing, after which a non-zero num_flush_bios should be required in dm for targets that map to underlying devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-14-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: freeze the queue in queue_attr_storeChristoph Hellwig
queue_attr_store updates attributes used to control generating I/O, and can cause malformed bios if changed with I/O in flight. Freeze the queue in common code instead of adding it to almost every attribute. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20240617060532.127975-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-09blk-throttle: delay initialization until configurationYu Kuai
Other cgroup policy like bfq, iocost are lazy-initialized when they are configured for the first time for the device, but blk-throttle is initialized unconditionally from blkcg_init_disk(). Delay initialization of blk-throttle as well, to save some cpu and memory overhead if it's not configured. Noted that once it's initialized, it can't be destroyed until disk removal, even if it's disabled. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240509121107.3195568-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-09blk-throttle: remove CONFIG_BLK_DEV_THROTTLING_LOWYu Kuai
One the one hand, it's marked EXPERIMENTAL since 2017, and looks like there are no users since then, and no testers and no developers, it's just not active at all. On the other hand, even if the config is disabled, there are still many fields in throtl_grp and throtl_data and many functions that are only used for throtl low. At last, currently blk-throtl is initialized during disk initialization, and destroyed during disk removal, and it exposes many functions to be called directly from block layer. Remove throtl low to make code much more cleaner and follow up work much easier. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20240509121107.3195568-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17block: Allow zero value of max_zone_append_sectors queue limitDamien Le Moal
In preparation for adding a generic zone append emulation using zone write plugging, allow device drivers supporting zoned block device to set a the max_zone_append_sectors queue limit of a device to 0 to indicate the lack of native support for zone append operations and that the block layer should emulate these operations using regular write operations. blk_queue_max_zone_append_sectors() is modified to allow passing 0 as the max_zone_append_sectors argument. The function queue_max_zone_append_sectors() is also modified to ensure that the minimum of the max_hw_sectors and chunk_sectors limit is used whenever the max_zone_append_sectors limit is 0. This minimum is consistent with the value set for the max_zone_append_sectors limit by the function blk_validate_zoned_limits() when limits for a queue are validated. The helper functions queue_emulates_zone_append() and bdev_emulates_zone_append() are added to test if a queue (or block device) emulates zone append operations. In order for blk_revalidate_disk_zones() to accept zoned block devices relying on zone append emulation, the direct check to the max_zone_append_sectors queue limit of the disk is replaced by a check using the value returned by queue_max_zone_append_sectors(). Similarly, queue_zone_append_max_show() is modified to use the same accessor so that the sysfs attribute advertizes the non-zero limit that will be used, regardless if it is for native or emulated commands. For stacking drivers, a top device should not need to care if the underlying devices have native or emulated zone append operations. blk_stack_limits() is thus modified to set the top device max_zone_append_sectors limit using the new accessor queue_limits_max_zone_append_sectors(). queue_max_zone_append_sectors() is modified to use this function as well. Stacking drivers that require zone append emulation, e.g. dm-crypt, can still request this feature by calling blk_queue_max_zone_append_sectors() with a 0 limit. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Hans Holmberg <hans.holmberg@wdc.com> Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20240408014128.205141-10-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-13block: use queue_limits_commit_update in queue_discard_max_storeChristoph Hellwig
Convert queue_discard_max_store to use queue_limits_commit_update to check and update the max_discard_sectors limit and freeze the queue before doing so to ensure we don't have requests in flight while changing the limits. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240213073425.1621680-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-13block: add a max_user_discard_sectors queue limitChristoph Hellwig
Add a new max_user_discard_sectors limit that mirrors max_user_sectors and stores the value that the user manually set. This now allows updates of the max_hw_discard_sectors to not worry about the user limit. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240213073425.1621680-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-13block: use queue_limits_commit_update in queue_max_sectors_storeChristoph Hellwig
Convert queue_max_sectors_store to use queue_limits_commit_update to check and update the max_sectors limit and freeze the queue before doing so to ensure we don't have requests in flight while changing the limits. Note that this removes the previously held queue_lock that doesn't protect against any other reader or writer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240213073425.1621680-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-11Merge tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: "Pretty quiet round this time around. This contains: - NVMe updates via Keith: - nvme fabrics spec updates (Guixin, Max) - nvme target udpates (Guixin, Evan) - nvme attribute refactoring (Daniel) - nvme-fc numa fix (Keith) - MD updates via Song: - Fix/Cleanup RCU usage from conf->disks[i].rdev (Yu Kuai) - Fix raid5 hang issue (Junxiao Bi) - Add Yu Kuai as Reviewer of the md subsystem - Remove deprecated flavors (Song Liu) - raid1 read error check support (Li Nan) - Better handle events off-by-1 case (Alex Lyakas) - Efficiency improvements for passthrough (Kundan) - Support for mapping integrity data directly (Keith) - Zoned write fix (Damien) - rnbd fixes (Kees, Santosh, Supriti) - Default to a sane discard size granularity (Christoph) - Make the default max transfer size naming less confusing (Christoph) - Remove support for deprecated host aware zoned model (Christoph) - Misc fixes (me, Li, Matthew, Min, Ming, Randy, liyouhong, Daniel, Bart, Christoph)" * tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linux: (78 commits) block: Treat sequential write preferred zone type as invalid block: remove disk_clear_zoned sd: remove the !ZBC && blk_queue_is_zoned case in sd_read_block_characteristics drivers/block/xen-blkback/common.h: Fix spelling typo in comment blk-cgroup: fix rcu lockdep warning in blkg_lookup() blk-cgroup: don't use removal safe list iterators block: floor the discard granularity to the physical block size mtd_blkdevs: use the default discard granularity bcache: use the default discard granularity zram: use the default discard granularity null_blk: use the default discard granularity nbd: use the default discard granularity ubd: use the default discard granularity block: default the discard granularity to sector size bcache: discard_granularity should not be smaller than a sector block: remove two comments in bio_split_discard block: rename and document BLK_DEF_MAX_SECTORS loop: don't abuse BLK_DEF_MAX_SECTORS aoe: don't abuse BLK_DEF_MAX_SECTORS null_blk: don't cap max_hw_sectors to BLK_DEF_MAX_SECTORS ...
2023-12-27block: rename and document BLK_DEF_MAX_SECTORSChristoph Hellwig
Give BLK_DEF_MAX_SECTORS a _CAP postfix and document what it is used for. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20231227092305.279567-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-19block: remove support for the host aware zone modelChristoph Hellwig
When zones were first added the SCSI and ATA specs, two different models were supported (in addition to the drive managed one that is invisible to the host): - host managed where non-conventional zones there is strict requirement to write at the write pointer, or else an error is returned - host aware where a write point is maintained if writes always happen at it, otherwise it is left in an under-defined state and the sequential write preferred zones behave like conventional zones (probably very badly performing ones, though) Not surprisingly this lukewarm model didn't prove to be very useful and was finally removed from the ZBC and SBC specs (NVMe never implemented it). Due to to the easily disappearing write pointer host software could never rely on the write pointer to actually be useful for say recovery. Fortunately only a few HDD prototypes shipped using this model which never made it to mass production. Drop the support before it is too late. Note that any such host aware prototype HDD can still be used with Linux as we'll now treat it as a conventional HDD. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20231217165359.604246-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-29block: Document the role of the two attribute groupsBart Van Assche
It is nontrivial to derive the role of the two attribute groups in source file block/blk-sysfs.c. Hence add a comment that explains their roles. See also commit 6d85ebf95c44 ("blk-sysfs: add a new attr_group for blk_mq"). Cc: Christoph Hellwig <hch@lst.de> Cc: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20231128194019.72762-1-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17block: don't allow enabling a cache on devices that don't support itChristoph Hellwig
Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC flag on devices that never claimed the capability. Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by blk_queue_write_cache and guards re-enabling the cache through sysfs. Note that any rescan that calls blk_queue_write_cache will still re-enable the write cache as in the current code. Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device") Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17block: cleanup queue_wc_storeChristoph Hellwig
Get rid of the local queue_wc_store variable and handling setting and clearing the QUEUE_FLAG_WC flag diretly instead the if / else if. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230707094239.107968-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-26blk-sysfs: add a new attr_group for blk_mqYu Kuai
Currently wbt sysfs entry is created for bio based device, and wbt can be enabled for such device through sysfs while it doesn't make sense because wbt can only work for rq based device. In the meantime, there are other similar sysfs entries. Fix this by adding a new attr_group for blk_mq, and sysfs entries will only be created when the device is rq based. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230527010644.647900-6-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-26blk-wbt: don't create wbt sysfs entry if CONFIG_BLK_WBT is disabledYu Kuai
sysfs entry /sys/block/[device]/queue/wbt_lat_usec will be created even if CONFIG_BLK_WBT is disabled, while read and write will always fail. It doesn't make sense to create a sysfs entry that can't be accessed, so don't create such entry. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230527010644.647900-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: include <linux/blk-mq.h> in block/blk-mq.hChristoph Hellwig
block/blk-mq.h needs various definitions from <linux/blk-mq.h>, include it there instead of relying on the source files to include both. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-20blk-mq: remove hybrid pollingKeith Busch
io_uring provides the only way user space can poll completions, and that always sets BLK_POLL_NOSLEEP. This effectively makes hybrid polling dead code, so remove it and everything supporting it. Hybrid polling was effectively killed off with 9650b453a3d4b1, "block: ignore RWF_HIPRI hint for sync dio", but still potentially reachable through io_uring until d729cf9acb93119, "io_uring: don't sleep when polling for I/O", but hybrid polling probably should not have been reachable through that async interface from the beginning. Fixes: 9650b453a3d4 ("block: ignore RWF_HIPRI hint for sync dio") Fixes: d729cf9acb93 ("io_uring: don't sleep when polling for I/O") Signed-off-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20230320194926.3353144-1-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-09block: make kobj_type structures constantThomas Weißschuh
Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the driver core allows the usage of const struct kobj_type. Take advantage of this to constify the structure definitions to prevent modification at runtime. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20230208-kobj_type-block-v1-1-0b3eafd7d983@weissschuh.net Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03blk-wbt: move private information from blk-wbt.h to blk-wbt.cChristoph Hellwig
A large part of blk-wbt.h is only used in blk-wbt.c, so move it there. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230203150400.3199230-11-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03blk-wbt: pass a gendisk to wbt_initChristoph Hellwig
Pass a gendisk to wbt_init to prepare for phasing out usage of the request_queue in the blk-cgroup code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230203150400.3199230-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03blk-wbt: pass a gendisk to wbt_{enable,disable}_defaultChristoph Hellwig
Pass a gendisk to wbt_enable_default and wbt_disable_default to prepare for phasing out usage of the request_queue in the blk-cgroup code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230203150400.3199230-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29block: save user max_sectors limitKeith Busch
The user can set the max_sectors limit to any valid value via sysfs /sys/block/<dev>/queue/max_sectors_kb attribute. If the device limits are ever rescanned, though, the limit reverts back to the potentially artificially low BLK_DEF_MAX_SECTORS value. Preserve the user's setting as the max_sectors limit as long as it's valid. The user can reset back to defaults by writing 0 to the sysfs file. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20230105205146.3610282-3-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30block: untangle request_queue refcounting from sysfsChristoph Hellwig
The kobject embedded into the request_queue is used for the queue directory in sysfs, but that is a child of the gendisks directory and is intimately tied to it. Move this kobject to the gendisk and use a refcount_t in the request_queue for the actual request_queue refcounting that is completely unrelated to the device model. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221114042637.1009333-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30block: fix error unwinding in blk_register_queueChristoph Hellwig
blk_register_queue fails to handle errors from blk_mq_sysfs_register, leaks various resources on errors and accidentally sets queue refs percpu refcount to percpu mode on kobject_add failure. Fix all that by properly unwinding on errors. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221114042637.1009333-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30block: factor out a blk_debugfs_remove helperChristoph Hellwig
Split the debugfs removal from blk_unregister_queue into a helper so that the it can be reused for blk_register_queue error handling. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221114042637.1009333-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30blk-crypto: pass a gendisk to blk_crypto_sysfs_{,un}registerChristoph Hellwig
Prepare for changes to the block layer sysfs handling by passing the readily available gendisk to blk_crypto_sysfs_{,un}register. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20221114042637.1009333-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-02blk-mq: move the srcu_struct used for quiescing to the tagsetChristoph Hellwig
All I/O submissions have fairly similar latencies, and a tagset-wide quiesce is a fairly common operation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Chao Leng <lengchao@huawei.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20221101150050.3510-12-hch@lst.de [axboe: fix whitespace] Signed-off-by: Jens Axboe <axboe@kernel.dk>
generated by cgit (git 2.34.1) at 2025-04-02 06:39:06 +0000