kernel/linux.git/block, branch v6.12.80

blk-throttle: fix access race during throttle policy activation

2026-03-25T10:08:45+00:00

[ Upstream commit bd9fd5be6bc0836820500f68fff144609fbd85a9 ] On repeated cold boots we occasionally hit a NULL pointer crash in blk_should_throtl() when throttling is consulted before the throttle policy is fully enabled for the queue. Checking only q->td != NULL is insufficient during early initialization, so blkg_to_pd() for the throttle policy can still return NULL and blkg_to_tg() becomes NULL, which later gets dereferenced. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000156 ... pc : submit_bio_noacct+0x14c/0x4c8 lr : submit_bio_noacct+0x48/0x4c8 sp : ffff800087f0b690 x29: ffff800087f0b690 x28: 0000000000005f90 x27: ffff00068af393c0 x26: 0000000000080000 x25: 000000000002fbc0 x24: ffff000684ddcc70 x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000 x20: 0000000000080000 x19: ffff000684ddcd08 x18: ffffffffffffffff x17: 0000000000000000 x16: ffff80008132a550 x15: 0000ffff98020fff x14: 0000000000000000 x13: 1fffe000d11d7021 x12: ffff000688eb810c x11: ffff00077ec4bb80 x10: ffff000688dcb720 x9 : ffff80008068ef60 x8 : 00000a6fb8a86e85 x7 : 000000000000111e x6 : 0000000000000002 x5 : 0000000000000246 x4 : 0000000000015cff x3 : 0000000000394500 x2 : ffff000682e35e40 x1 : 0000000000364940 x0 : 000000000000001a Call trace: submit_bio_noacct+0x14c/0x4c8 verity_map+0x178/0x2c8 __map_bio+0x228/0x250 dm_submit_bio+0x1c4/0x678 __submit_bio+0x170/0x230 submit_bio_noacct_nocheck+0x16c/0x388 submit_bio_noacct+0x16c/0x4c8 submit_bio+0xb4/0x210 f2fs_submit_read_bio+0x4c/0xf0 f2fs_mpage_readpages+0x3b0/0x5f0 f2fs_readahead+0x90/0xe8 Tighten blk_throtl_activated() to also require that the throttle policy bit is set on the queue: return q->td != NULL && test_bit(blkcg_policy_throtl.plid, q->blkcg_pols); This prevents blk_should_throtl() from accessing throttle group state until policy data has been attached to blkgs. Fixes: a3166c51702b ("blk-throttle: delay initialization until configuration") Co-developed-by: Liang Jie Signed-off-by: Liang Jie Signed-off-by: Han Guangjiang Reviewed-by: Yu Kuai Signed-off-by: Jens Axboe Signed-off-by: Robert Garcia Signed-off-by: Greg Kroah-Hartman

block: decouple secure erase size limit from discard size limit

2026-03-04T12:20:56+00:00

[ Upstream commit ee81212f74a57c5d2b56cf504f40d528dac6faaf ] Secure erase should use max_secure_erase_sectors instead of being limited by max_discard_sectors. Separate the handling of REQ_OP_SECURE_ERASE from REQ_OP_DISCARD to allow each operation to use its own size limit. Signed-off-by: Luke Wang Reviewed-by: Ulf Hansson Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()

2026-03-04T12:20:56+00:00

[ Upstream commit 9d20fd6ce1ba9733cd5ac96fcab32faa9fc404dd ] In blk_mq_update_nr_hw_queues(), debugfs_mutex is not held while creating debugfs entries for hctxs. Hence add debugfs_mutex there, it's safe because queue is not frozen. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: add a bio_add_virt_nofail helper

2026-03-04T12:19:26+00:00

[ Upstream commit 850e210d5ad21b94b55b97d4d82b4cdeb0bb05df ] Add a helper to add a directly mapped kernel virtual address to a bio so that callers don't have to convert to pages or folios. For now only the _nofail variant is provided as that is what all the obvious callers want. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250507120451.4000627-2-hch@lst.de Signed-off-by: Jens Axboe Stable-dep-of: 4ac9690d4b94 ("rnbd-srv: Fix server side setting of bi_size for special IOs") Signed-off-by: Sasha Levin

block,bfq: fix aux stat accumulation destination

2026-02-11T12:40:19+00:00

[ Upstream commit 04bdb1a04d8a2a89df504c1e34250cd3c6e31a1c ] Route bfqg_stats_add_aux() time accumulation into the destination stats object instead of the source, aligning with other stat fields. Reviewed-by: Yu Kuai Signed-off-by: shechenglong Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix NULL pointer dereference in blk_zone_reset_all_bio_endio()

2026-01-08T09:15:06+00:00

commit c2b8d20628ca789640f64074a642f9440eefc623 upstream. For zoned block devices that do not need zone write plugs (e.g. most device mapper devices that support zones), the disk hash table of zone write plugs is NULL. For such devices, blk_zone_reset_all_bio_endio() should not attempt to scan this has table as that causes a NULL pointer dereference. Fix this by checking that the disk does have zone write plugs using the atomic counter. This is equivalent to checking for a non-NULL hash table but has the advantage to also speed up the execution of blk_zone_reset_all_bio_endio() for devices that do use zone write plugs but do not have any plug in the hash table (e.g. a disk with only full zones). Fixes: efae226c2ef1 ("block: handle zone management operations completions") Reported-by: Shin'ichiro Kawasaki Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: handle zone management operations completions

2026-01-08T09:15:04+00:00

[ Upstream commit efae226c2ef19528ffd81d29ba0eecf1b0896ca2 ] The functions blk_zone_wplug_handle_reset_or_finish() and blk_zone_wplug_handle_reset_all() both modify the zone write pointer offset of zone write plugs that are the target of a reset, reset all or finish zone management operation. However, these functions do this modification before the BIO is executed. So if the zone operation fails, the modified zone write pointer offsets become invalid. Avoid this by modifying the zone write pointer offset of a zone write plug that is the target of a zone management operation when the operation completes. To do so, modify blk_zone_bio_endio() to call the new function blk_zone_mgmt_bio_endio() which in turn calls the functions blk_zone_reset_all_bio_endio(), blk_zone_reset_bio_endio() or blk_zone_finish_bio_endio() depending on the operation of the completed BIO, to modify a zone write plug write pointer offset accordingly. These functions are called only if the BIO execution was successful. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe [ adapted bdev_zone_is_seq() check to disk_zone_is_conv() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

block: freeze queue when updating zone resources

2026-01-08T09:14:58+00:00

[ Upstream commit bba4322e3f303b2d656e748be758320b567f046f ] Modify disk_update_zone_resources() to freeze the device queue before updating the number of zones, zone capacity and other zone related resources. The locking order resulting from the call to queue_limits_commit_update_frozen() is preserved, that is, the queue limits lock is first taken by calling queue_limits_start_update() before freezing the queue, and the queue is unfrozen after executing queue_limits_commit_update(), which replaces the call to queue_limits_commit_update_frozen(). This change ensures that there are no in-flights I/Os when the zone resources are updated due to a zone revalidation. In case of error when the limits are applied, directly call disk_free_zone_resources() from disk_update_zone_resources() while the disk queue is still frozen to avoid needing to freeze & unfreeze the queue again in blk_revalidate_disk_zones(), thus simplifying that function code a little. Fixes: 0b83c86b444a ("block: Prevent potential deadlock in blk_revalidate_disk_zones()") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe [ adapted blk_mq_freeze_queue/unfreeze_queue calls to single-argument void API ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

block: Clear BLK_ZONE_WPLUG_PLUGGED when aborting plugged BIOs

2026-01-08T09:14:42+00:00

commit 552c1149af7ac0cffab6fccd13feeaf816dd1f53 upstream. Commit fe0418eb9bd6 ("block: Prevent potential deadlocks in zone write plug error recovery") added a WARN check in disk_put_zone_wplug() to verify that when the last reference to a zone write plug is dropped, this zone write plug does not have the BLK_ZONE_WPLUG_PLUGGED flag set, that is, that it is not plugged. However, the function disk_zone_wplug_abort(), which is called for zone reset and zone finish operations, does not clear this flag after emptying a zone write plug BIO list. This can result in the disk_put_zone_wplug() warning to trigger if the user (erroneously as that is bad pratcice) issues zone reset or zone finish operations while the target zone still has plugged BIOs. Modify disk_put_zone_wplug() to clear the BLK_ZONE_WPLUG_PLUGGED flag. And while at it, also add a lockdep annotation to ensure that this function is called with the zone write plug spinlock held. Fixes: fe0418eb9bd6 ("block: Prevent potential deadlocks in zone write plug error recovery") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Niklas Cassel Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

blk-mq: skip CPU offline notify on unmapped hctx

2026-01-08T09:14:37+00:00

[ Upstream commit 10845a105bbcb030647a729f1716c2309da71d33 ] If an hctx has no software ctx mapped, blk_mq_map_swqueue() never allocates tags and leaves hctx->tags NULL. The CPU hotplug offline notifier can still run for that hctx, return early since hctx cannot hold any requests. Signed-off-by: Cong Zhang Fixes: bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are offline") Reviewed-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin