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2025-02-21partitions: mac: fix handling of bogus partition tableJann Horn
commit 80e648042e512d5a767da251d44132553fe04ae0 upstream. Fix several issues in partition probing: - The bailout for a bad partoffset must use put_dev_sector(), since the preceding read_part_sector() succeeded. - If the partition table claims a silly sector size like 0xfff bytes (which results in partition table entries straddling sector boundaries), bail out instead of accessing out-of-bounds memory. - We must not assume that the partition table contains proper NUL termination - use strnlen() and strncmp() instead of strlen() and strcmp(). Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20250214-partition-mac-v1-1-c1c626dffbd5@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-17block: don't revert iter for -EIOCBQUEUEDJens Axboe
commit b13ee668e8280ca5b07f8ce2846b9957a8a10853 upstream. blkdev_read_iter() has a few odd checks, like gating the position and count adjustment on whether or not the result is bigger-than-or-equal to zero (where bigger than makes more sense), and not checking the return value of blkdev_direct_IO() before doing an iov_iter_revert(). The latter can lead to attempting to revert with a negative value, which when passed to iov_iter_revert() as an unsigned value will lead to throwing a WARN_ON() because unroll is bigger than MAX_RW_COUNT. Be sane and don't revert for -EIOCBQUEUED, like what is done in other spots. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-17blk-cgroup: Fix class @block_class's subsystem refcount leakageZijun Hu
commit d1248436cbef1f924c04255367ff4845ccd9025e upstream. blkcg_fill_root_iostats() iterates over @block_class's devices by class_dev_iter_(init|next)(), but does not end iterating with class_dev_iter_exit(), so causes the class's subsystem refcount leakage. Fix by ending the iterating with class_dev_iter_exit(). Fixes: ef45fe470e1e ("blk-cgroup: show global disk stats in root cgroup io.stat") Reviewed-by: Michal Koutný <mkoutny@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-2-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-17block: mark GFP_NOIO around sysfs ->store()Ming Lei
commit 7c0be4ead1f8f5f8be0803f347de0de81e3b8e1c upstream. sysfs ->store is called with queue freezed, meantime we have several ->store() callbacks(update_nr_requests, wbt, scheduler) to allocate memory with GFP_KERNEL which may run into direct reclaim code path, then potential deadlock can be caused. Fix the issue by marking NOIO around sysfs ->store() Reported-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250113015833.698458-1-ming.lei@redhat.com Link: https://lore.kernel.org/linux-block/Z4RkemI9f6N5zoEF@fedora/T/#mc774c65eeca5c024d29695f9ac6152b87763f305 Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-08block: Ensure start sector is aligned for stacking atomic writesJohn Garry
[ Upstream commit 6564862d646e7d630929ba1ff330740bb215bdac ] For stacking atomic writes, ensure that the start sector is aligned with the device atomic write unit min and any boundary. Otherwise, we may permit misaligned atomic writes. Rework bdev_can_atomic_write() into a common helper to resuse the alignment check. There also use atomic_write_hw_unit_min, which is more proper (than atomic_write_unit_min). Fixes: d7f36dc446e89 ("block: Support atomic writes limits for stacked devices") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250109114000.2299896-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08partitions: ldm: remove the initial kernel-doc notationRandy Dunlap
[ Upstream commit e494e451611a3de6ae95f99e8339210c157d70fb ] Remove the file's first comment describing what the file is. This comment is not in kernel-doc format so it causes a kernel-doc warning. ldm.h:13: warning: expecting prototype for ldm(). Prototype was for _FS_PT_LDM_H_() instead Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Richard Russon (FlatCap) <ldm@flatcap.org> Cc: linux-ntfs-dev@lists.sourceforge.net Cc: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20250111062758.910458-1-rdunlap@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: fix queue freeze vs limits lock order in sysfs store methodsChristoph Hellwig
[ Upstream commit c99f66e4084a62a2cc401c4704a84328aeddc9ec ] queue_attr_store() always freezes a device queue before calling the attribute store operation. For attributes that control queue limits, the store operation will also lock the queue limits with a call to queue_limits_start_update(). However, some drivers (e.g. SCSI sd) may need to issue commands to a device to obtain limit values from the hardware with the queue limits locked. This creates a potential ABBA deadlock situation if a user attempts to modify a limit (thus freezing the device queue) while the device driver starts a revalidation of the device queue limits. Avoid such deadlock by not freezing the queue before calling the ->store_limit() method in struct queue_sysfs_entry and instead use the queue_limits_commit_update_frozen helper to freeze the queue after taking the limits lock. This also removes taking the sysfs lock for the store_limit method as it doesn't protect anything here, but creates even more nesting. Hopefully it will go away from the actual sysfs methods entirely soon. (commit log adapted from a similar patch from Damien Le Moal) Fixes: ff956a3be95b ("block: use queue_limits_commit_update in queue_discard_max_store") Fixes: 0327ca9d53bf ("block: use queue_limits_commit_update in queue_max_sectors_store") Signed-off-by: Christoph Hellwig <hch@lst.de> 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: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250110054726.1499538-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: add a store_limit operations for sysfs entriesChristoph Hellwig
[ Upstream commit a16230649ce27f8ac7dd8a5b079d9657aa96de16 ] De-duplicate the code for updating queue limits by adding a store_limit method that allows having common code handle the actual queue limits update. Note that this is a pure refactoring patch and does not address the existing freeze vs limits lock order problem in the refactored code, which will be addressed next. Signed-off-by: Christoph Hellwig <hch@lst.de> 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: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250110054726.1499538-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: c99f66e4084a ("block: fix queue freeze vs limits lock order in sysfs store methods") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: add a queue_limits_commit_update_frozen helperChristoph Hellwig
[ Upstream commit aa427d7b73b196f657d6d2cf0e94eff6b883fdef ] Add a helper that freezes the queue, updates the queue limits and unfreezes the queue and convert all open coded versions of that to the new helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.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: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250110054726.1499538-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: c99f66e4084a ("block: fix queue freeze vs limits lock order in sysfs store methods") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: don't update BLK_FEAT_POLL in __blk_mq_update_nr_hw_queuesChristoph Hellwig
[ Upstream commit d432c817c21a48c3baaa0d28e4d3e74b6aa238a0 ] When __blk_mq_update_nr_hw_queues changes the number of tag sets, it might have to disable poll queues. Currently it does so by adjusting the BLK_FEAT_POLL, which is a bit against the intent of features that describe hardware / driver capabilities, but more importantly causes nasty lock order problems with the broadly held freeze when updating the number of hardware queues and the limits lock. Fix this by leaving BLK_FEAT_POLL alone, and instead check for the number of poll queues in the bio submission and poll handlers. While this adds extra work to the fast path, the variables are in cache lines used by these operations anyway, so it should be cheap enough. Fixes: 8023e144f9d6 ("block: move the poll flag to queue_limits") Signed-off-by: Christoph Hellwig <hch@lst.de> 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: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Link: https://lore.kernel.org/r/20250110054726.1499538-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: check BLK_FEAT_POLL under q_usage_countChristoph Hellwig
[ Upstream commit 958148a6ac061a9a80a184ea678a5fa872d0c56f ] Otherwise feature reconfiguration can race with I/O submission. Also drop the bio_clear_polled in the error path, as the flag does not matter for instant error completions, it is a left over from when we allowed polled I/O to proceed unpolled in this case. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250110054726.1499538-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: d432c817c21a ("block: don't update BLK_FEAT_POLL in __blk_mq_update_nr_hw_queues") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: retry call probe after request_module in blk_request_moduleYang Erkun
[ Upstream commit 457ef47c08d2979f3e59ce66267485c3faed70c8 ] Set kernel config: CONFIG_BLK_DEV_LOOP=m CONFIG_BLK_DEV_LOOP_MIN_COUNT=0 Do latter: mknod loop0 b 7 0 exec 4<> loop0 Before commit e418de3abcda ("block: switch gendisk lookup to a simple xarray"), lookup_gendisk will first use base_probe to load module loop, and then the retry will call loop_probe to prepare the loop disk. Finally open for this disk will success. However, after this commit, we lose the retry logic, and open will fail with ENXIO. Block device autoloading is deprecated and will be removed soon, but maybe we should keep open success until we really remove it. So, give a retry to fix it. Fixes: e418de3abcda ("block: switch gendisk lookup to a simple xarray") Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241209110435.3670985-1-yangerkun@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08block: copy back bounce buffer to user-space correctly in case of splitChristoph Hellwig
[ Upstream commit 031141976be0bd5f385775727a4ed3cc845eb7ba ] Copy back the bounce buffer to user-space in entirety when the parent bio completes. The existing code uses bip_iter.bi_size for sizing the copy, which can be modified. So move away from that and fetch it from the vector passed to the block layer. While at it, switch to using better variable names. Fixes: 492c5d455969f ("block: bio-integrity: directly map user buffers") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20241128112240.8867-3-anuj20.g@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09block, bfq: fix waker_bfqq UAF after bfq_split_bfqq()Yu Kuai
Our syzkaller report a following UAF for v6.6: BUG: KASAN: slab-use-after-free in bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958 Read of size 8 at addr ffff8881b57147d8 by task fsstress/232726 CPU: 2 PID: 232726 Comm: fsstress Not tainted 6.6.0-g3629d1885222 #39 Call Trace: <TASK> __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 hlist_add_head include/linux/list.h:1023 [inline] bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143 __submit_bio+0xa0/0x6b0 block/blk-core.c:639 __submit_bio_noacct_mq block/blk-core.c:718 [inline] submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847 __ext4_read_bh fs/ext4/super.c:205 [inline] ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230 __read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567 ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947 ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182 ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660 ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569 iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91 iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80 ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051 ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220 do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811 __do_sys_ioctl fs/ioctl.c:869 [inline] __se_sys_ioctl+0xae/0x190 fs/ioctl.c:857 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 Allocated by task 232719: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:768 [inline] slab_alloc_node mm/slub.c:3492 [inline] kmem_cache_alloc_node+0x1b8/0x6f0 mm/slub.c:3537 bfq_get_queue+0x215/0x1f00 block/bfq-iosched.c:5869 bfq_get_bfqq_handle_split+0x167/0x5f0 block/bfq-iosched.c:6776 bfq_init_rq+0x13a4/0x17a0 block/bfq-iosched.c:6938 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143 __submit_bio+0xa0/0x6b0 block/blk-core.c:639 __submit_bio_noacct_mq block/blk-core.c:718 [inline] submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847 __ext4_read_bh fs/ext4/super.c:205 [inline] ext4_read_bh_nowait+0x15a/0x240 fs/ext4/super.c:217 ext4_read_bh_lock+0xac/0xd0 fs/ext4/super.c:242 ext4_bread_batch+0x268/0x500 fs/ext4/inode.c:958 __ext4_find_entry+0x448/0x10f0 fs/ext4/namei.c:1671 ext4_lookup_entry fs/ext4/namei.c:1774 [inline] ext4_lookup.part.0+0x359/0x6f0 fs/ext4/namei.c:1842 ext4_lookup+0x72/0x90 fs/ext4/namei.c:1839 __lookup_slow+0x257/0x480 fs/namei.c:1696 lookup_slow fs/namei.c:1713 [inline] walk_component+0x454/0x5c0 fs/namei.c:2004 link_path_walk.part.0+0x773/0xda0 fs/namei.c:2331 link_path_walk fs/namei.c:3826 [inline] path_openat+0x1b9/0x520 fs/namei.c:3826 do_filp_open+0x1b7/0x400 fs/namei.c:3857 do_sys_openat2+0x5dc/0x6e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x148/0x200 fs/open.c:1454 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 232726: 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:1827 [inline] slab_free_freelist_hook mm/slub.c:1853 [inline] slab_free mm/slub.c:3820 [inline] kmem_cache_free+0x110/0x760 mm/slub.c:3842 bfq_put_queue+0x6a7/0xfb0 block/bfq-iosched.c:5428 bfq_forget_entity block/bfq-wf2q.c:634 [inline] bfq_put_idle_entity+0x142/0x240 block/bfq-wf2q.c:645 bfq_forget_idle+0x189/0x1e0 block/bfq-wf2q.c:671 bfq_update_vtime block/bfq-wf2q.c:1280 [inline] __bfq_lookup_next_entity block/bfq-wf2q.c:1374 [inline] bfq_lookup_next_entity+0x350/0x480 block/bfq-wf2q.c:1433 bfq_update_next_in_service+0x1c0/0x4f0 block/bfq-wf2q.c:128 bfq_deactivate_entity+0x10a/0x240 block/bfq-wf2q.c:1188 bfq_deactivate_bfqq block/bfq-wf2q.c:1592 [inline] bfq_del_bfqq_busy+0x2e8/0xad0 block/bfq-wf2q.c:1659 bfq_release_process_ref+0x1cc/0x220 block/bfq-iosched.c:3139 bfq_split_bfqq+0x481/0xdf0 block/bfq-iosched.c:6754 bfq_init_rq+0xf29/0x17a0 block/bfq-iosched.c:6934 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143 __submit_bio+0xa0/0x6b0 block/blk-core.c:639 __submit_bio_noacct_mq block/blk-core.c:718 [inline] submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847 __ext4_read_bh fs/ext4/super.c:205 [inline] ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230 __read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567 ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947 ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182 ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660 ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569 iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91 iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80 ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051 ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220 do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811 __do_sys_ioctl fs/ioctl.c:869 [inline] __se_sys_ioctl+0xae/0x190 fs/ioctl.c:857 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 commit 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting") fix the problem that if waker_bfqq is in the merge chain, and current is the only procress, waker_bfqq can be freed from bfq_split_bfqq(). However, the case that waker_bfqq is not in the merge chain is missed, and if the procress reference of waker_bfqq is 0, waker_bfqq can be freed as well. Fix the problem by checking procress reference if waker_bfqq is not in the merge_chain. Fixes: 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20250108084148.1549973-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-18block: avoid to reuse `hctx` not removed from cpuhp callback listMing Lei
If the 'hctx' isn't removed from cpuhp callback list, we can't reuse it, otherwise use-after-free may be triggered. Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202412172217.b906db7c-lkp@intel.com Tested-by: kernel test robot <oliver.sang@intel.com> Fixes: 22465bbac53c ("blk-mq: move cpuhp callback registering out of q->sysfs_lock") Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20241218101617.3275704-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
2024-12-18block/bdev: use helper for max block size checkLuis Chamberlain
We already have a helper for checking the limits on the block size both low and high, just use that. No functional changes. Reviewed-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241218020212.3657139-2-mcgrof@kernel.org 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>
2024-12-13blk-mq: Clean up blk_mq_requeue_work()Bart Van Assche
Move a statement that occurs in both branches of an if-statement in front of the if-statement. Fix a typo in a source code comment. No functionality has been changed. Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241212212941.1268662-3-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-13mq-deadline: Remove a local variableBart Van Assche
Since commit fde02699c242 ("block: mq-deadline: Remove support for zone write locking"), the local variable 'insert_before' is assigned once and is used once. Hence remove this local variable. Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241212212941.1268662-2-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-12blk-iocost: Avoid using clamp() on inuse in __propagate_weights()Nathan Chancellor
After a recent change to clamp() and its variants [1] that increases the coverage of the check that high is greater than low because it can be done through inlining, certain build configurations (such as s390 defconfig) fail to build with clang with: block/blk-iocost.c:1101:11: error: call to '__compiletime_assert_557' declared with 'error' attribute: clamp() low limit 1 greater than high limit active 1101 | inuse = clamp_t(u32, inuse, 1, active); | ^ include/linux/minmax.h:218:36: note: expanded from macro 'clamp_t' 218 | #define clamp_t(type, val, lo, hi) __careful_clamp(type, val, lo, hi) | ^ include/linux/minmax.h:195:2: note: expanded from macro '__careful_clamp' 195 | __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) | ^ include/linux/minmax.h:188:2: note: expanded from macro '__clamp_once' 188 | BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \ | ^ __propagate_weights() is called with an active value of zero in ioc_check_iocgs(), which results in the high value being less than the low value, which is undefined because the value returned depends on the order of the comparisons. The purpose of this expression is to ensure inuse is not more than active and at least 1. This could be written more simply with a ternary expression that uses min(inuse, active) as the condition so that the value of that condition can be used if it is not zero and one if it is. Do this conversion to resolve the error and add a comment to deter people from turning this back into clamp(). Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Link: https://lore.kernel.org/r/34d53778977747f19cce2abb287bb3e6@AcuMS.aculab.com/ [1] Suggested-by: David Laight <david.laight@aculab.com> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/llvm/CA+G9fYsD7mw13wredcZn0L-KBA3yeoVSTuxnss-AEWMN3ha0cA@mail.gmail.com/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202412120322.3GfVe3vF-lkp@intel.com/ Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-12block: Make bio_iov_bvec_set() accept pointer to const iov_iterJohn Garry
Make bio_iov_bvec_set() accept a pointer to const iov_iter, which means that we can drop the undesirable casting to struct iov_iter pointer in blk_rq_map_user_bvec(). Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241202115727.2320401-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-10block: get wp_offset by bdev_offset_from_zone_startLongPing Wei
Call bdev_offset_from_zone_start() instead of open-coding it. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Signed-off-by: LongPing Wei <weilongping@oppo.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20241107020439.1644577-1-weilongping@oppo.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-10blk-cgroup: Fix UAF in blkcg_unpin_online()Tejun Heo
blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To walk up, it uses blkcg_parent(blkcg) but it was calling that after blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the following UAF: ================================================================== BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270 Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117 CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022 Workqueue: cgwb_release cgwb_release_workfn Call Trace: <TASK> dump_stack_lvl+0x27/0x80 print_report+0x151/0x710 kasan_report+0xc0/0x100 blkcg_unpin_online+0x15a/0x270 cgwb_release_workfn+0x194/0x480 process_scheduled_works+0x71b/0xe20 worker_thread+0x82a/0xbd0 kthread+0x242/0x2c0 ret_from_fork+0x33/0x70 ret_from_fork_asm+0x1a/0x30 </TASK> ... Freed by task 1944: kasan_save_track+0x2b/0x70 kasan_save_free_info+0x3c/0x50 __kasan_slab_free+0x33/0x50 kfree+0x10c/0x330 css_free_rwork_fn+0xe6/0xb30 process_scheduled_works+0x71b/0xe20 worker_thread+0x82a/0xbd0 kthread+0x242/0x2c0 ret_from_fork+0x33/0x70 ret_from_fork_asm+0x1a/0x30 Note that the UAF is not easy to trigger as the free path is indirected behind a couple RCU grace periods and a work item execution. I could only trigger it with artifical msleep() injected in blkcg_unpin_online(). Fix it by reading the parent pointer before destroying the blkcg's blkg's. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Abagail ren <renzezhongucas@gmail.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Fixes: 4308a434e5e0 ("blkcg: don't offline parent blkcg first") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-10block: Prevent potential deadlocks in zone write plug error recoveryDamien Le Moal
Zone write plugging for handling writes to zones of a zoned block device always execute a zone report whenever a write BIO to a zone fails. The intent of this is to ensure that the tracking of a zone write pointer is always correct to ensure that the alignment to a zone write pointer of write BIOs can be checked on submission and that we can always correctly emulate zone append operations using regular write BIOs. However, this error recovery scheme introduces a potential deadlock if a device queue freeze is initiated while BIOs are still plugged in a zone write plug and one of these write operation fails. In such case, the disk zone write plug error recovery work is scheduled and executes a report zone. This in turn can result in a request allocation in the underlying driver to issue the report zones command to the device. But with the device queue freeze already started, this allocation will block, preventing the report zone execution and the continuation of the processing of the plugged BIOs. As plugged BIOs hold a queue usage reference, the queue freeze itself will never complete, resulting in a deadlock. Avoid this problem by completely removing from the zone write plugging code the use of report zones operations after a failed write operation, instead relying on the device user to either execute a report zones, reset the zone, finish the zone, or give up writing to the device (which is a fairly common pattern for file systems which degrade to read-only after write failures). This is not an unreasonnable requirement as all well-behaved applications, FSes and device mapper already use report zones to recover from write errors whenever possible by comparing the current position of a zone write pointer with what their assumption about the position is. The changes to remove the automatic error recovery are as follows: - Completely remove the error recovery work and its associated resources (zone write plug list head, disk error list, and disk zone_wplugs_work work struct). This also removes the functions disk_zone_wplug_set_error() and disk_zone_wplug_clear_error(). - Change the BLK_ZONE_WPLUG_ERROR zone write plug flag into BLK_ZONE_WPLUG_NEED_WP_UPDATE. This new flag is set for a zone write plug whenever a write opration targetting the zone of the zone write plug fails. This flag indicates that the zone write pointer offset is not reliable and that it must be updated when the next report zone, reset zone, finish zone or disk revalidation is executed. - Modify blk_zone_write_plug_bio_endio() to set the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag for the target zone of a failed write BIO. - Modify the function disk_zone_wplug_set_wp_offset() to clear this new flag, thus implementing recovery of a correct write pointer offset with the reset (all) zone and finish zone operations. - Modify blkdev_report_zones() to always use the disk_report_zones_cb() callback so that disk_zone_wplug_sync_wp_offset() can be called for any zone marked with the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag. This implements recovery of a correct write pointer offset for zone write plugs marked with BLK_ZONE_WPLUG_NEED_WP_UPDATE and within the range of the report zones operation executed by the user. - Modify blk_revalidate_seq_zone() to call disk_zone_wplug_sync_wp_offset() for all sequential write required zones when a zoned block device is revalidated, thus always resolving any inconsistency between the write pointer offset of zone write plugs and the actual write pointer position of sequential zones. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241209122357.47838-5-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-10dm: Fix dm-zoned-reclaim zone write pointer alignmentDamien Le Moal
The zone reclaim processing of the dm-zoned device mapper uses blkdev_issue_zeroout() to align the write pointer of a zone being used for reclaiming another zone, to write the valid data blocks from the zone being reclaimed at the same position relative to the zone start in the reclaim target zone. The first call to blkdev_issue_zeroout() will try to use hardware offload using a REQ_OP_WRITE_ZEROES operation if the device reports a non-zero max_write_zeroes_sectors queue limit. If this operation fails because of the lack of hardware support, blkdev_issue_zeroout() falls back to using a regular write operation with the zero-page as buffer. Currently, such REQ_OP_WRITE_ZEROES failure is automatically handled by the block layer zone write plugging code which will execute a report zones operation to ensure that the write pointer of the target zone of the failed operation has not changed and to "rewind" the zone write pointer offset of the target zone as it was advanced when the write zero operation was submitted. So the REQ_OP_WRITE_ZEROES failure does not cause any issue and blkdev_issue_zeroout() works as expected. However, since the automatic recovery of zone write pointers by the zone write plugging code can potentially cause deadlocks with queue freeze operations, a different recovery must be implemented in preparation for the removal of zone write plugging report zones based recovery. Do this by introducing the new function blk_zone_issue_zeroout(). This function first calls blkdev_issue_zeroout() with the flag BLKDEV_ZERO_NOFALLBACK to intercept failures on the first execution which attempt to use the device hardware offload with the REQ_OP_WRITE_ZEROES operation. If this attempt fails, a report zone operation is issued to restore the zone write pointer offset of the target zone to the correct position and blkdev_issue_zeroout() is called again without the BLKDEV_ZERO_NOFALLBACK flag. The report zones operation performing this recovery is implemented using the helper function disk_zone_sync_wp_offset() which calls the gendisk report_zones file operation with the callback disk_report_zones_cb(). This callback updates the target write pointer offset of the target zone using the new function disk_zone_wplug_sync_wp_offset(). dmz_reclaim_align_wp() is modified to change its call to blkdev_issue_zeroout() to a call to blk_zone_issue_zeroout() without any other change needed as the two functions are functionnally equivalent. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241209122357.47838-4-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-10block: Ignore REQ_NOWAIT for zone reset and zone finish operationsDamien Le Moal
There are currently any issuer of REQ_OP_ZONE_RESET and REQ_OP_ZONE_FINISH operations that set REQ_NOWAIT. However, as we cannot handle this flag correctly due to the potential request allocation failure that may happen in blk_mq_submit_bio() after blk_zone_plug_bio() has handled the zone write plug write pointer updates for the targeted zones, modify blk_zone_wplug_handle_reset_or_finish() to warn if this flag is set and ignore it. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241209122357.47838-3-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-10block: Use a zone write plug BIO work for REQ_NOWAIT BIOsDamien Le Moal
For zoned block devices, a write BIO issued to a zone that has no on-going writes will be prepared for execution and allowed to execute immediately by blk_zone_wplug_handle_write() (called from blk_zone_plug_bio()). However, if this BIO specifies REQ_NOWAIT, the allocation of a request for its execution in blk_mq_submit_bio() may fail after blk_zone_plug_bio() completed, marking the target zone of the BIO as plugged. When this BIO is retried later on, it will be blocked as the zone write plug of the target zone is in a plugged state without any on-going write operation (completion of write operations trigger unplugging of the next write BIOs for a zone). This leads to a BIO that is stuck in a zone write plug and never completes, which results in various issues such as hung tasks. Avoid this problem by always executing REQ_NOWAIT write BIOs using the BIO work of a zone write plug. This ensure that we never block the BIO issuer and can thus safely ignore the REQ_NOWAIT flag when executing the BIO from the zone write plug BIO work. Since such BIO may be the first write BIO issued to a zone with no on-going write, modify disk_zone_wplug_add_bio() to schedule the zone write plug BIO work if the write plug is not already marked with the BLK_ZONE_WPLUG_PLUGGED flag. This scheduling is otherwise not necessary as the completion of the on-going write for the zone will schedule the execution of the next plugged BIOs. blk_zone_wplug_handle_write() is also fixed to better handle zone write plug allocation failures for REQ_NOWAIT BIOs by failing a write BIO using bio_wouldblock_error() instead of bio_io_error(). Reported-by: Bart Van Assche <bvanassche@acm.org> Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241209122357.47838-2-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-06blk-mq: move cpuhp callback registering out of q->sysfs_lockMing Lei
Registering and unregistering cpuhp callback requires global cpu hotplug lock, which is used everywhere. Meantime q->sysfs_lock is used in block layer almost everywhere. It is easy to trigger lockdep warning[1] by connecting the two locks. Fix the warning by moving blk-mq's cpuhp callback registering out of q->sysfs_lock. Add one dedicated global lock for covering registering & unregistering hctx's cpuhp, and it is safe to do so because hctx is guaranteed to be live if our request_queue is live. [1] https://lore.kernel.org/lkml/Z04pz3AlvI4o0Mr8@agluck-desk3/ Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Peter Newman <peternewman@google.com> Cc: Babu Moger <babu.moger@amd.com> Reported-by: Luck Tony <tony.luck@intel.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/20241206111611.978870-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-06blk-mq: register cpuhp callback after hctx is added to xarray tableMing Lei
We need to retrieve 'hctx' from xarray table in the cpuhp callback, so the callback should be registered after this 'hctx' is added to xarray table. Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Peter Newman <peternewman@google.com> Cc: Babu Moger <babu.moger@amd.com> Cc: Luck Tony <tony.luck@intel.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/20241206111611.978870-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-30Merge tag 'block-6.13-20242901' of git://git.kernel.dk/linuxLinus Torvalds
Pull more block updates from Jens Axboe: - NVMe pull request via Keith: - Use correct srcu list traversal (Breno) - Scatter-gather support for metadata (Keith) - Fabrics shutdown race condition fix (Nilay) - Persistent reservations updates (Guixin) - Add the required bits for MD atomic write support for raid0/1/10 - Correct return value for unknown opcode in ublk - Fix deadlock with zone revalidation - Fix for the io priority request vs bio cleanups - Use the correct unsigned int type for various limit helpers - Fix for a race in loop - Cleanup blk_rq_prep_clone() to prevent uninit-value warning and make it easier for actual humans to read - Fix potential UAF when iterating tags - A few fixes for bfq-iosched UAF issues - Fix for brd discard not decrementing the allocated page count - Various little fixes and cleanups * tag 'block-6.13-20242901' of git://git.kernel.dk/linux: (36 commits) brd: decrease the number of allocated pages which discarded block, bfq: fix bfqq uaf in bfq_limit_depth() block: Don't allow an atomic write be truncated in blkdev_write_iter() mq-deadline: don't call req_get_ioprio from the I/O completion handler block: Prevent potential deadlock in blk_revalidate_disk_zones() block: Remove extra part pointer NULLify in blk_rq_init() nvme: tuning pr code by using defined structs and macros nvme: introduce change ptpl and iekey definition block: return bool from get_disk_ro and bdev_read_only block: remove a duplicate definition for bdev_read_only block: return bool from blk_rq_aligned block: return unsigned int from blk_lim_dma_alignment_and_pad block: return unsigned int from queue_dma_alignment block: return unsigned int from bdev_io_opt block: req->bio is always set in the merge code block: don't bother checking the data direction for merges block: blk-mq: fix uninit-value in blk_rq_prep_clone and refactor Revert "block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()" md/raid10: Atomic write support md/raid1: Atomic write support ...
2024-11-29block, bfq: fix bfqq uaf in bfq_limit_depth()Yu Kuai
Set new allocated bfqq to bic or remove freed bfqq from bic are both protected by bfqd->lock, however bfq_limit_depth() is deferencing bfqq from bic without the lock, this can lead to UAF if the io_context is shared by multiple tasks. For example, test bfq with io_uring can trigger following UAF in v6.6: ================================================================== BUG: KASAN: slab-use-after-free in bfqq_group+0x15/0x50 Call Trace: <TASK> dump_stack_lvl+0x47/0x80 print_address_description.constprop.0+0x66/0x300 print_report+0x3e/0x70 kasan_report+0xb4/0xf0 bfqq_group+0x15/0x50 bfqq_request_over_limit+0x130/0x9a0 bfq_limit_depth+0x1b5/0x480 __blk_mq_alloc_requests+0x2b5/0xa00 blk_mq_get_new_requests+0x11d/0x1d0 blk_mq_submit_bio+0x286/0xb00 submit_bio_noacct_nocheck+0x331/0x400 __block_write_full_folio+0x3d0/0x640 writepage_cb+0x3b/0xc0 write_cache_pages+0x254/0x6c0 write_cache_pages+0x254/0x6c0 do_writepages+0x192/0x310 filemap_fdatawrite_wbc+0x95/0xc0 __filemap_fdatawrite_range+0x99/0xd0 filemap_write_and_wait_range.part.0+0x4d/0xa0 blkdev_read_iter+0xef/0x1e0 io_read+0x1b6/0x8a0 io_issue_sqe+0x87/0x300 io_wq_submit_work+0xeb/0x390 io_worker_handle_work+0x24d/0x550 io_wq_worker+0x27f/0x6c0 ret_from_fork_asm+0x1b/0x30 </TASK> Allocated by task 808602: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_slab_alloc+0x83/0x90 kmem_cache_alloc_node+0x1b1/0x6d0 bfq_get_queue+0x138/0xfa0 bfq_get_bfqq_handle_split+0xe3/0x2c0 bfq_init_rq+0x196/0xbb0 bfq_insert_request.isra.0+0xb5/0x480 bfq_insert_requests+0x156/0x180 blk_mq_insert_request+0x15d/0x440 blk_mq_submit_bio+0x8a4/0xb00 submit_bio_noacct_nocheck+0x331/0x400 __blkdev_direct_IO_async+0x2dd/0x330 blkdev_write_iter+0x39a/0x450 io_write+0x22a/0x840 io_issue_sqe+0x87/0x300 io_wq_submit_work+0xeb/0x390 io_worker_handle_work+0x24d/0x550 io_wq_worker+0x27f/0x6c0 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0x1b/0x30 Freed by task 808589: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x27/0x40 __kasan_slab_free+0x126/0x1b0 kmem_cache_free+0x10c/0x750 bfq_put_queue+0x2dd/0x770 __bfq_insert_request.isra.0+0x155/0x7a0 bfq_insert_request.isra.0+0x122/0x480 bfq_insert_requests+0x156/0x180 blk_mq_dispatch_plug_list+0x528/0x7e0 blk_mq_flush_plug_list.part.0+0xe5/0x590 __blk_flush_plug+0x3b/0x90 blk_finish_plug+0x40/0x60 do_writepages+0x19d/0x310 filemap_fdatawrite_wbc+0x95/0xc0 __filemap_fdatawrite_range+0x99/0xd0 filemap_write_and_wait_range.part.0+0x4d/0xa0 blkdev_read_iter+0xef/0x1e0 io_read+0x1b6/0x8a0 io_issue_sqe+0x87/0x300 io_wq_submit_work+0xeb/0x390 io_worker_handle_work+0x24d/0x550 io_wq_worker+0x27f/0x6c0 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0x1b/0x30 Fix the problem by protecting bic_to_bfqq() with bfqd->lock. CC: Jan Kara <jack@suse.cz> Fixes: 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20241129091509.2227136-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-27block: Don't allow an atomic write be truncated in blkdev_write_iter()John Garry
A write which goes past the end of the bdev in blkdev_write_iter() will be truncated. Truncating cannot tolerated for an atomic write, so error that condition. Fixes: caf336f81b3a ("block: Add fops atomic write support") Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241127092318.632790-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-26mq-deadline: don't call req_get_ioprio from the I/O completion handlerChristoph Hellwig
req_get_ioprio looks at req->bio to find the I/O priority, which is not set when completing bios that the driver fully iterated through. Stash away the dd_per_prio in the elevator private data instead of looking it up again to optimize the code a bit while fixing the regression from removing the per-request ioprio value. Fixes: 6975c1a486a4 ("block: remove the ioprio field from struct request") Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com> Reported-by: Sam Protsenko <semen.protsenko@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com> Tested-by: Sam Protsenko <semen.protsenko@linaro.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20241126102136.619067-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-26block: Prevent potential deadlock in blk_revalidate_disk_zones()Damien Le Moal
The function blk_revalidate_disk_zones() calls the function disk_update_zone_resources() after freezing the device queue. In turn, disk_update_zone_resources() calls queue_limits_start_update() which takes a queue limits mutex lock, resulting in the ordering: q->q_usage_counter check -> q->limits_lock. However, the usual ordering is to always take a queue limit lock before freezing the queue to commit the limits updates, e.g., the code pattern: lim = queue_limits_start_update(q); ... blk_mq_freeze_queue(q); ret = queue_limits_commit_update(q, &lim); blk_mq_unfreeze_queue(q); Thus, blk_revalidate_disk_zones() introduces a potential circular locking dependency deadlock that lockdep sometimes catches with the splat: [ 51.934109] ====================================================== [ 51.935916] WARNING: possible circular locking dependency detected [ 51.937561] 6.12.0+ #2107 Not tainted [ 51.938648] ------------------------------------------------------ [ 51.940351] kworker/u16:4/157 is trying to acquire lock: [ 51.941805] ffff9fff0aa0bea8 (&q->limits_lock){+.+.}-{4:4}, at: disk_update_zone_resources+0x86/0x170 [ 51.944314] but task is already holding lock: [ 51.945688] ffff9fff0aa0b890 (&q->q_usage_counter(queue)#3){++++}-{0:0}, at: blk_revalidate_disk_zones+0x15f/0x340 [ 51.948527] which lock already depends on the new lock. [ 51.951296] the existing dependency chain (in reverse order) is: [ 51.953708] -> #1 (&q->q_usage_counter(queue)#3){++++}-{0:0}: [ 51.956131] blk_queue_enter+0x1c9/0x1e0 [ 51.957290] blk_mq_alloc_request+0x187/0x2a0 [ 51.958365] scsi_execute_cmd+0x78/0x490 [scsi_mod] [ 51.959514] read_capacity_16+0x111/0x410 [sd_mod] [ 51.960693] sd_revalidate_disk.isra.0+0x872/0x3240 [sd_mod] [ 51.962004] sd_probe+0x2d7/0x520 [sd_mod] [ 51.962993] really_probe+0xd5/0x330 [ 51.963898] __driver_probe_device+0x78/0x110 [ 51.964925] driver_probe_device+0x1f/0xa0 [ 51.965916] __driver_attach_async_helper+0x60/0xe0 [ 51.967017] async_run_entry_fn+0x2e/0x140 [ 51.968004] process_one_work+0x21f/0x5a0 [ 51.968987] worker_thread+0x1dc/0x3c0 [ 51.969868] kthread+0xe0/0x110 [ 51.970377] ret_from_fork+0x31/0x50 [ 51.970983] ret_from_fork_asm+0x11/0x20 [ 51.971587] -> #0 (&q->limits_lock){+.+.}-{4:4}: [ 51.972479] __lock_acquire+0x1337/0x2130 [ 51.973133] lock_acquire+0xc5/0x2d0 [ 51.973691] __mutex_lock+0xda/0xcf0 [ 51.974300] disk_update_zone_resources+0x86/0x170 [ 51.975032] blk_revalidate_disk_zones+0x16c/0x340 [ 51.975740] sd_zbc_revalidate_zones+0x73/0x160 [sd_mod] [ 51.976524] sd_revalidate_disk.isra.0+0x465/0x3240 [sd_mod] [ 51.977824] sd_probe+0x2d7/0x520 [sd_mod] [ 51.978917] really_probe+0xd5/0x330 [ 51.979915] __driver_probe_device+0x78/0x110 [ 51.981047] driver_probe_device+0x1f/0xa0 [ 51.982143] __driver_attach_async_helper+0x60/0xe0 [ 51.983282] async_run_entry_fn+0x2e/0x140 [ 51.984319] process_one_work+0x21f/0x5a0 [ 51.985873] worker_thread+0x1dc/0x3c0 [ 51.987289] kthread+0xe0/0x110 [ 51.988546] ret_from_fork+0x31/0x50 [ 51.989926] ret_from_fork_asm+0x11/0x20 [ 51.991376] other info that might help us debug this: [ 51.994127] Possible unsafe locking scenario: [ 51.995651] CPU0 CPU1 [ 51.996694] ---- ---- [ 51.997716] lock(&q->q_usage_counter(queue)#3); [ 51.998817] lock(&q->limits_lock); [ 52.000043] lock(&q->q_usage_counter(queue)#3); [ 52.001638] lock(&q->limits_lock); [ 52.002485] *** DEADLOCK *** Prevent this issue by moving the calls to blk_mq_freeze_queue() and blk_mq_unfreeze_queue() around the call to queue_limits_commit_update() in disk_update_zone_resources(). In case of revalidation failure, the call to disk_free_zone_resources() in blk_revalidate_disk_zones() is still done with the queue frozen as before. Fixes: 843283e96e5a ("block: Fake max open zones limit when there is no limit") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241126104705.183996-1-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-25block: Remove extra part pointer NULLify in blk_rq_init()John Garry
The rq->part pointer is already NULLified in the memset() call, so - like for other pointers in rq - don't re-NULLify. Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20241125100258.4172774-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: req->bio is always set in the merge codeChristoph Hellwig
As smatch, which is a lot smarter than me noticed. So remove the checks for it, and condense these checks a bit including the comments stating the obvious. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241119161157.1328171-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: don't bother checking the data direction for mergesChristoph Hellwig
Because it already is encoded in the opcode. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241119161157.1328171-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: blk-mq: fix uninit-value in blk_rq_prep_clone and refactorSuraj Sonawane
Fix an issue detected by the `smatch` tool: block/blk-mq.c:3314 blk_rq_prep_clone() error: uninitialized symbol 'bio'. This patch refactors `blk_rq_prep_clone()` to improve code readability and ensure safety by addressing potential misuse of the `bio` variable: - Move the bio_put(bio); call to the bio_ctr error handling block, which is the only place where it can be triggered. - Move the bio variable into the __rq_for_each_bio loop scope. This change removes the need to set bio to NULL at the loop's end. discussion on why bio remains uninitialized: https://lore.kernel.org/lkml/20241004141037.43277-1-surajsonawane0215@gmail.com Summary of above discussion: - I pointed out that `bio` can remain uninitialized if the allocation with `bio_alloc_clone` fails. - Keith Busch explained that `bio` is initialized to `NULL` when `bio_alloc_clone()` fails, preventing uninitialized usage. - John Garry questioned whether `rq_src->bio` being `NULL` could leave `bio` uninitialized. Keith clarified that in such cases, `bio` is not referenced, so it does not need initialization. - Christoph Hellwig recommended code improvements: - move the bio_put to the bio_ctr error handling, which is the only case where it can happen - move the bio variable into the __rq_for_each_bio scope, which also removed the need to zero it at the end of the loop These changes enhance code clarity, address static analysis tool warnings, and make the function more maintainable. thread of previous version patch discussion: https://lore.kernel.org/lkml/20241004100842.9052-1-surajsonawane0215@gmail.com Signed-off-by: Suraj Sonawane <surajsonawane0215@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241119164412.37609-1-surajsonawane0215@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19Revert "block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()"Zach Wade
This reverts commit bc3b1e9e7c50e1de0f573eea3871db61dd4787de. The bic is associated with sync_bfqq, and bfq_release_process_ref cannot be put into bfq_put_cooperator. kasan report: [ 400.347277] ================================================================== [ 400.347287] BUG: KASAN: slab-use-after-free in bic_set_bfqq+0x200/0x230 [ 400.347420] Read of size 8 at addr ffff88881cab7d60 by task dockerd/5800 [ 400.347430] [ 400.347436] CPU: 24 UID: 0 PID: 5800 Comm: dockerd Kdump: loaded Tainted: G E 6.12.0 #32 [ 400.347450] Tainted: [E]=UNSIGNED_MODULE [ 400.347454] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.20192059.B64.2207280713 07/28/2022 [ 400.347460] Call Trace: [ 400.347464] <TASK> [ 400.347468] dump_stack_lvl+0x5d/0x80 [ 400.347490] print_report+0x174/0x505 [ 400.347521] kasan_report+0xe0/0x160 [ 400.347541] bic_set_bfqq+0x200/0x230 [ 400.347549] bfq_bic_update_cgroup+0x419/0x740 [ 400.347560] bfq_bio_merge+0x133/0x320 [ 400.347584] blk_mq_submit_bio+0x1761/0x1e20 [ 400.347625] __submit_bio+0x28b/0x7b0 [ 400.347664] submit_bio_noacct_nocheck+0x6b2/0xd30 [ 400.347690] iomap_readahead+0x50c/0x680 [ 400.347731] read_pages+0x17f/0x9c0 [ 400.347785] page_cache_ra_unbounded+0x366/0x4a0 [ 400.347795] filemap_fault+0x83d/0x2340 [ 400.347819] __xfs_filemap_fault+0x11a/0x7d0 [xfs] [ 400.349256] __do_fault+0xf1/0x610 [ 400.349270] do_fault+0x977/0x11a0 [ 400.349281] __handle_mm_fault+0x5d1/0x850 [ 400.349314] handle_mm_fault+0x1f8/0x560 [ 400.349324] do_user_addr_fault+0x324/0x970 [ 400.349337] exc_page_fault+0x76/0xf0 [ 400.349350] asm_exc_page_fault+0x26/0x30 [ 400.349360] RIP: 0033:0x55a480d77375 [ 400.349384] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 49 3b 66 10 0f 86 ae 02 00 00 55 48 89 e5 48 83 ec 58 48 8b 10 <83> 7a 10 00 0f 84 27 02 00 00 44 0f b6 42 28 44 0f b6 4a 29 41 80 [ 400.349392] RSP: 002b:00007f18c37fd8b8 EFLAGS: 00010216 [ 400.349401] RAX: 00007f18c37fd9d0 RBX: 0000000000000000 RCX: 0000000000000000 [ 400.349407] RDX: 000055a484407d38 RSI: 000000c000e8b0c0 RDI: 0000000000000000 [ 400.349412] RBP: 00007f18c37fd910 R08: 000055a484017f60 R09: 000055a484066f80 [ 400.349417] R10: 0000000000194000 R11: 0000000000000005 R12: 0000000000000008 [ 400.349422] R13: 0000000000000000 R14: 000000c000476a80 R15: 0000000000000000 [ 400.349430] </TASK> [ 400.349452] [ 400.349454] Allocated by task 5800: [ 400.349459] kasan_save_stack+0x30/0x50 [ 400.349469] kasan_save_track+0x14/0x30 [ 400.349475] __kasan_slab_alloc+0x89/0x90 [ 400.349482] kmem_cache_alloc_node_noprof+0xdc/0x2a0 [ 400.349492] bfq_get_queue+0x1ef/0x1100 [ 400.349502] __bfq_get_bfqq_handle_split+0x11a/0x510 [ 400.349511] bfq_insert_requests+0xf55/0x9030 [ 400.349519] blk_mq_flush_plug_list+0x446/0x14c0 [ 400.349527] __blk_flush_plug+0x27c/0x4e0 [ 400.349534] blk_finish_plug+0x52/0xa0 [ 400.349540] _xfs_buf_ioapply+0x739/0xc30 [xfs] [ 400.350246] __xfs_buf_submit+0x1b2/0x640 [xfs] [ 400.350967] xfs_buf_read_map+0x306/0xa20 [xfs] [ 400.351672] xfs_trans_read_buf_map+0x285/0x7d0 [xfs] [ 400.352386] xfs_imap_to_bp+0x107/0x270 [xfs] [ 400.353077] xfs_iget+0x70d/0x1eb0 [xfs] [ 400.353786] xfs_lookup+0x2ca/0x3a0 [xfs] [ 400.354506] xfs_vn_lookup+0x14e/0x1a0 [xfs] [ 400.355197] __lookup_slow+0x19c/0x340 [ 400.355204] lookup_one_unlocked+0xfc/0x120 [ 400.355211] ovl_lookup_single+0x1b3/0xcf0 [overlay] [ 400.355255] ovl_lookup_layer+0x316/0x490 [overlay] [ 400.355295] ovl_lookup+0x844/0x1fd0 [overlay] [ 400.355351] lookup_one_qstr_excl+0xef/0x150 [ 400.355357] do_unlinkat+0x22a/0x620 [ 400.355366] __x64_sys_unlinkat+0x109/0x1e0 [ 400.355375] do_syscall_64+0x82/0x160 [ 400.355384] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 400.355393] [ 400.355395] Freed by task 5800: [ 400.355400] kasan_save_stack+0x30/0x50 [ 400.355407] kasan_save_track+0x14/0x30 [ 400.355413] kasan_save_free_info+0x3b/0x70 [ 400.355422] __kasan_slab_free+0x4f/0x70 [ 400.355429] kmem_cache_free+0x176/0x520 [ 400.355438] bfq_put_queue+0x67e/0x980 [ 400.355447] bfq_bic_update_cgroup+0x407/0x740 [ 400.355454] bfq_bio_merge+0x133/0x320 [ 400.355460] blk_mq_submit_bio+0x1761/0x1e20 [ 400.355467] __submit_bio+0x28b/0x7b0 [ 400.355473] submit_bio_noacct_nocheck+0x6b2/0xd30 [ 400.355480] iomap_readahead+0x50c/0x680 [ 400.355490] read_pages+0x17f/0x9c0 [ 400.355498] page_cache_ra_unbounded+0x366/0x4a0 [ 400.355505] filemap_fault+0x83d/0x2340 [ 400.355514] __xfs_filemap_fault+0x11a/0x7d0 [xfs] [ 400.356204] __do_fault+0xf1/0x610 [ 400.356213] do_fault+0x977/0x11a0 [ 400.356221] __handle_mm_fault+0x5d1/0x850 [ 400.356230] handle_mm_fault+0x1f8/0x560 [ 400.356238] do_user_addr_fault+0x324/0x970 [ 400.356248] exc_page_fault+0x76/0xf0 [ 400.356258] asm_exc_page_fault+0x26/0x30 [ 400.356266] [ 400.356269] The buggy address belongs to the object at ffff88881cab7bc0 which belongs to the cache bfq_queue of size 576 [ 400.356276] The buggy address is located 416 bytes inside of freed 576-byte region [ffff88881cab7bc0, ffff88881cab7e00) [ 400.356285] [ 400.356287] The buggy address belongs to the physical page: [ 400.356292] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88881cab0b00 pfn:0x81cab0 [ 400.356300] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 [ 400.356323] flags: 0x50000000000040(head|node=1|zone=2) [ 400.356331] page_type: f5(slab) [ 400.356340] raw: 0050000000000040 ffff88880a00c280 dead000000000122 0000000000000000 [ 400.356347] raw: ffff88881cab0b00 00000000802e0025 00000001f5000000 0000000000000000 [ 400.356354] head: 0050000000000040 ffff88880a00c280 dead000000000122 0000000000000000 [ 400.356359] head: ffff88881cab0b00 00000000802e0025 00000001f5000000 0000000000000000 [ 400.356365] head: 0050000000000003 ffffea002072ac01 ffffffffffffffff 0000000000000000 [ 400.356370] head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 [ 400.356378] page dumped because: kasan: bad access detected [ 400.356381] [ 400.356383] Memory state around the buggy address: [ 400.356387] ffff88881cab7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 400.356392] ffff88881cab7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 400.356397] >ffff88881cab7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 400.356400] ^ [ 400.356405] ffff88881cab7d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 400.356409] ffff88881cab7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 400.356413] ================================================================== Cc: stable@vger.kernel.org Fixes: bc3b1e9e7c50 ("block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()") Signed-off-by: Zach Wade <zachwade.k@gmail.com> Cc: Ding Hui <dinghui@sangfor.com.cn> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20241119153410.2546-1-zachwade.k@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: Support atomic writes limits for stacked devicesJohn Garry
Allow stacked devices to support atomic writes by aggregating the minimum capability of all bottom devices. Flag BLK_FEAT_ATOMIC_WRITES_STACKED is set for stacked devices which have been enabled to support atomic writes. Some things to note on the implementation: - For simplicity, all bottom devices must have same atomic write boundary value (if any) - The atomic write boundary must be a power-of-2 already, but this restriction could be relaxed. Furthermore, it is now required that the chunk sectors for a top device must be aligned with this boundary. - If a bottom device atomic write unit min/max are not aligned with the top device chunk sectors, the top device atomic write unit min/max are reduced to a value which works for the chunk sectors. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241118105018.1870052-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: Add extra checks in blk_validate_atomic_write_limits()John Garry
It is so far expected that the limits passed are valid. In future atomic writes will be supported for stacked block devices, and calculating the limits there will be complicated, so add extra sanity checks to ensure that the values are always valid. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241118105018.1870052-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: Drop granularity check in queue_limit_discard_alignment()John Garry
lim->discard_granularity is always at least SECTOR_SIZE, so drop the pointless check for granularity less than SECTOR_SIZE. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241112092144.4059847-1-john.g.garry@oracle.com 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>
2024-11-18Merge tag 'for-6.13/block-20241118' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: - NVMe updates via Keith: - Use uring_cmd helper (Pavel) - Host Memory Buffer allocation enhancements (Christoph) - Target persistent reservation support (Guixin) - Persistent reservation tracing (Guixen) - NVMe 2.1 specification support (Keith) - Rotational Meta Support (Matias, Wang, Keith) - Volatile cache detection enhancment (Guixen) - MD updates via Song: - Maintainers update - raid5 sync IO fix - Enhance handling of faulty and blocked devices - raid5-ppl atomic improvement - md-bitmap fix - Support for manually defining embedded partition tables - Zone append fixes and cleanups - Stop sending the queued requests in the plug list to the driver ->queue_rqs() handle in reverse order. - Zoned write plug cleanups - Cleanups disk stats tracking and add support for disk stats for passthrough IO - Add preparatory support for file system atomic writes - Add lockdep support for queue freezing. Already found a bunch of issues, and some fixes for that are in here. More will be coming. - Fix race between queue stopping/quiescing and IO queueing - ublk recovery improvements - Fix ublk mmap for 64k pages - Various fixes and cleanups * tag 'for-6.13/block-20241118' of git://git.kernel.dk/linux: (118 commits) MAINTAINERS: Update git tree for mdraid subsystem block: make struct rq_list available for !CONFIG_BLOCK block/genhd: use seq_put_decimal_ull for diskstats decimal values block: don't reorder requests in blk_mq_add_to_batch block: don't reorder requests in blk_add_rq_to_plug block: add a rq_list type block: remove rq_list_move virtio_blk: reverse request order in virtio_queue_rqs nvme-pci: reverse request order in nvme_queue_rqs btrfs: validate queue limits block: export blk_validate_limits nvmet: add tracing of reservation commands nvme: parse reservation commands's action and rtype to string nvmet: report ns's vwc not present md/raid5: Increase r5conf.cache_name size block: remove the ioprio field from struct request block: remove the write_hint field from struct request nvme: check ns's volatile write cache not present nvme: add rotational support nvme: use command set independent id ns if available ...
2024-11-18blk-settings: round down io_opt to physical_block_sizeMikulas Patocka
There was a bug report [1] where the user got a warning alignment inconsistency. The user has optimal I/O 16776704 (0xFFFE00) and physical block size 4096. Note that the optimal I/O size may be set by the DMA engines or SCSI controllers and they have no knowledge about the disks attached to them, so the situation with optimal I/O not aligned to physical block size may happen. This commit makes blk_validate_limits round down optimal I/O size to the physical block size of the block device. Closes: https://lore.kernel.org/dm-devel/1426ad71-79b4-4062-b2bf-84278be66a5d@redhat.com/T/ [1] Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: a23634644afc ("block: take io_opt and io_min into account for max_sectors") Cc: stable@vger.kernel.org # v6.11+ Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/3dc0014b-9690-dc38-81c9-4a316a2d4fb2@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-18Merge tag 'vfs-6.13.untorn.writes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs untorn write support from Christian Brauner: "An atomic write is a write issed with torn-write protection. This means for a power failure or any hardware failure all or none of the data from the write will be stored, never a mix of old and new data. This work is already supported for block devices. If a block device is opened with O_DIRECT and the block device supports atomic write, then FMODE_CAN_ATOMIC_WRITE is added to the file of the opened block device. This contains the work to expand atomic write support to filesystems, specifically ext4 and XFS. Currently, only support for writing exactly one filesystem block atomically is added. Since it's now possible to have filesystem block size > page size for XFS, it's possible to write 4K+ blocks atomically on x86" * tag 'vfs-6.13.untorn.writes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: iomap: drop an obsolete comment in iomap_dio_bio_iter ext4: Do not fallback to buffered-io for DIO atomic write ext4: Support setting FMODE_CAN_ATOMIC_WRITE ext4: Check for atomic writes support in write iter ext4: Add statx support for atomic writes xfs: Support setting FMODE_CAN_ATOMIC_WRITE xfs: Validate atomic writes xfs: Support atomic write for statx fs: iomap: Atomic write support fs: Export generic_atomic_write_valid() block: Add bdev atomic write limits helpers fs/block: Check for IOCB_DIRECT in generic_atomic_write_valid() block/fs: Pass an iocb to generic_atomic_write_valid()
2024-11-13block/genhd: use seq_put_decimal_ull for diskstats decimal valuesDavid Wang
seq_printf is costly. For each block device, 19 decimal values are yielded in /proc/diskstats via seq_printf. On a system with 16 logical block devices, profiling for open/read/close sequences shows seq_printf took ~75% samples of diskstats_show: diskstats_show(92.626% 2269372/2450040) seq_printf(76.026% 1725313/2269372) vsnprintf(99.163% 1710866/1725313) format_decode(26.597% 455040/1710866) number(19.554% 334542/1710866) memcpy_orig(4.183% 71570/1710866) ... srso_return_thunk(0.009% 148/1725313) part_stat_read_all(8.030% 182236/2269372) One million rounds of open/read/close /proc/diskstats takes: real 0m37.687s user 0m0.264s sys 0m32.911s On average, each sequence tooks ~0.032ms With this patch, most decimal values are yield via seq_put_decimal_ull, performance is significantly improved: real 0m20.792s user 0m0.316s sys 0m20.463s On average, each sequence tooks ~0.020ms, a ~37.5% improvement. Signed-off-by: David Wang <00107082@163.com> Link: https://lore.kernel.org/r/20241108054500.4251-1-00107082@163.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-13block: don't reorder requests in blk_add_rq_to_plugChristoph Hellwig
Add requests to the tail of the list instead of the front so that they are queued up in submission order. Remove the re-reordering in blk_mq_dispatch_plug_list, virtio_queue_rqs and nvme_queue_rqs now that the list is ordered as expected. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241113152050.157179-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>