diff options
| author | Ming Lei <ming.lei@redhat.com> | 2025-05-05 17:17:46 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-05-06 16:43:42 +0300 |
| commit | 98e68f67020ce30e1a4d8e2d05d85a453738dfb8 (patch) | |
| tree | fee31e25526513c94265fbd80618fef40c2951f7 /include/linux | |
| parent | 5fad1490ef510e3b70ad8b0a5a1e28a26638a95f (diff) | |
| download | linux-98e68f67020ce30e1a4d8e2d05d85a453738dfb8.tar.xz | |
block: prevent adding/deleting disk during updating nr_hw_queues
Both adding/deleting disk code are reader of `nr_hw_queues`, so we can't
allow them in-progress when updating nr_hw_queues, kernel panic and
kasan has been reported in [1].
Prevent adding/deleting disk during updating nr_hw_queues by adding
rw_semaphore to tagset, write lock is grabbed in blk_mq_update_nr_hw_queues(),
and read lock is acquired when adding/deleting disk.
Also mark GFP_NOIO allocation scope for adding/deleting disk because
blk_mq_update_nr_hw_queues() is part of some driver's error handler.
This way avoids lot of trouble.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Suggested-by: Nilay Shroff <nilay@linux.ibm.com>
Reported-by: Nilay Shroff <nilay@linux.ibm.com>
Closes: https://lore.kernel.org/linux-block/a5896cdb-a59a-4a37-9f99-20522f5d2987@linux.ibm.com/
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250505141805.2751237-9-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/blk-mq.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 8eb9b3310167..ef84d53095a6 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -9,6 +9,7 @@ #include <linux/prefetch.h> #include <linux/srcu.h> #include <linux/rw_hint.h> +#include <linux/rwsem.h> struct blk_mq_tags; struct blk_flush_queue; @@ -527,6 +528,8 @@ struct blk_mq_tag_set { struct mutex tag_list_lock; struct list_head tag_list; struct srcu_struct *srcu; + + struct rw_semaphore update_nr_hwq_lock; }; /** |