diff options
| author | Christoph Hellwig <hch@lst.de> | 2024-02-13 08:34:14 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-02-13 08:56:59 -0700 |
| commit | d690cb8ae14bd377d422b7905b6959c7e7a45b95 (patch) | |
| tree | c909d6c4f74dfd4c69ba78d57aa8d737d9515cf3 /include/linux/blkdev.h | |
| parent | c490f226a0ea22639e81ac34edc884e238ea955a (diff) | |
block: add an API to atomically update queue limits
Add a new queue_limits_{start,commit}_update pair of functions that
allows taking an atomic snapshot of queue limits, update it, and
commit it if it passes validity checking. Also use the low-level
validation helper to implement blk_set_default_limits instead of
duplicating the initialization.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 251a11d2d2ae..d41d7fe93457 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -474,6 +474,7 @@ struct request_queue { struct mutex sysfs_lock; struct mutex sysfs_dir_lock; + struct mutex limits_lock; /* * for reusing dead hctx instance in case of updating @@ -862,6 +863,28 @@ static inline unsigned int blk_chunk_sectors_left(sector_t offset, return chunk_sectors - (offset & (chunk_sectors - 1)); } +/** + * queue_limits_start_update - start an atomic update of queue limits + * @q: queue to update + * + * This functions starts an atomic update of the queue limits. It takes a lock + * to prevent other updates and returns a snapshot of the current limits that + * the caller can modify. The caller must call queue_limits_commit_update() + * to finish the update. + * + * Context: process context. The caller must have frozen the queue or ensured + * that there is outstanding I/O by other means. + */ +static inline struct queue_limits +queue_limits_start_update(struct request_queue *q) + __acquires(q->limits_lock) +{ + mutex_lock(&q->limits_lock); + return q->limits; +} +int queue_limits_commit_update(struct request_queue *q, + struct queue_limits *lim); + /* * Access functions for manipulating queue properties */ |