diff options
| -rw-r--r-- | block/blk-settings.c | 16 | ||||
| -rw-r--r-- | block/elevator.c | 49 | ||||
| -rw-r--r-- | block/mq-deadline.c | 1 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 4 | ||||
| -rw-r--r-- | include/linux/elevator.h | 8 |
5 files changed, 67 insertions, 11 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index a058997b9cce..6bd1e3b082d8 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -832,6 +832,22 @@ void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) } EXPORT_SYMBOL_GPL(blk_queue_write_cache); +/** + * blk_queue_required_elevator_features - Set a queue required elevator features + * @q: the request queue for the target device + * @features: Required elevator features OR'ed together + * + * Tell the block layer that for the device controlled through @q, only the + * only elevators that can be used are those that implement at least the set of + * features specified by @features. + */ +void blk_queue_required_elevator_features(struct request_queue *q, + unsigned int features) +{ + q->required_elevator_features = features; +} +EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features); + static int __init blk_settings_init(void) { blk_max_low_pfn = max_low_pfn - 1; diff --git a/block/elevator.c b/block/elevator.c index 2944c129760c..ac7c8ad580ba 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -83,8 +83,26 @@ bool elv_bio_merge_ok(struct request *rq, struct bio *bio) } EXPORT_SYMBOL(elv_bio_merge_ok); -static bool elevator_match(const struct elevator_type *e, const char *name) +static inline bool elv_support_features(unsigned int elv_features, + unsigned int required_features) { + return (required_features & elv_features) == required_features; +} + +/** + * elevator_match - Test an elevator name and features + * @e: Scheduler to test + * @name: Elevator name to test + * @required_features: Features that the elevator must provide + * + * Return true is the elevator @e name matches @name and if @e provides all the + * the feratures spcified by @required_features. + */ +static bool elevator_match(const struct elevator_type *e, const char *name, + unsigned int required_features) +{ + if (!elv_support_features(e->elevator_features, required_features)) + return false; if (!strcmp(e->elevator_name, name)) return true; if (e->elevator_alias && !strcmp(e->elevator_alias, name)) @@ -93,15 +111,21 @@ static bool elevator_match(const struct elevator_type *e, const char *name) return false; } -/* - * Return scheduler with name 'name' +/** + * elevator_find - Find an elevator + * @name: Name of the elevator to find + * @required_features: Features that the elevator must provide + * + * Return the first registered scheduler with name @name and supporting the + * features @required_features and NULL otherwise. */ -static struct elevator_type *elevator_find(const char *name) +static struct elevator_type *elevator_find(const char *name, + unsigned int required_features) { struct elevator_type *e; list_for_each_entry(e, &elv_list, list) { - if (elevator_match(e, name)) + if (elevator_match(e, name, required_features)) return e; } @@ -120,12 +144,12 @@ static struct elevator_type *elevator_get(struct request_queue *q, spin_lock(&elv_list_lock); - e = elevator_find(name); + e = elevator_find(name, q->required_elevator_features); if (!e && try_loading) { spin_unlock(&elv_list_lock); request_module("%s-iosched", name); spin_lock(&elv_list_lock); - e = elevator_find(name); + e = elevator_find(name, q->required_elevator_features); } if (e && !try_module_get(e->elevator_owner)) @@ -525,7 +549,7 @@ int elv_register(struct elevator_type *e) /* register, don't allow duplicate names */ spin_lock(&elv_list_lock); - if (elevator_find(e->elevator_name)) { + if (elevator_find(e->elevator_name, 0)) { spin_unlock(&elv_list_lock); kmem_cache_destroy(e->icq_cache); return -EBUSY; @@ -709,7 +733,8 @@ static int __elevator_change(struct request_queue *q, const char *name) if (!e) return -EINVAL; - if (q->elevator && elevator_match(q->elevator->type, elevator_name)) { + if (q->elevator && + elevator_match(q->elevator->type, elevator_name, 0)) { elevator_put(e); return 0; } @@ -749,11 +774,13 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name) spin_lock(&elv_list_lock); list_for_each_entry(__e, &elv_list, list) { - if (elv && elevator_match(elv, __e->elevator_name)) { + if (elv && elevator_match(elv, __e->elevator_name, 0)) { len += sprintf(name+len, "[%s] ", elv->elevator_name); continue; } - if (elv_support_iosched(q)) + if (elv_support_iosched(q) && + elevator_match(__e, __e->elevator_name, + q->required_elevator_features)) len += sprintf(name+len, "%s ", __e->elevator_name); } spin_unlock(&elv_list_lock); diff --git a/block/mq-deadline.c b/block/mq-deadline.c index 35e84bc0ec8c..b490f47fd553 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -794,6 +794,7 @@ static struct elevator_type mq_deadline = { .elevator_attrs = deadline_attrs, .elevator_name = "mq-deadline", .elevator_alias = "deadline", + .elevator_features = ELEVATOR_F_ZBD_SEQ_WRITE, .elevator_owner = THIS_MODULE, }; MODULE_ALIAS("mq-deadline-iosched"); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d0ad21e4771b..b196124e3240 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -496,6 +496,8 @@ struct request_queue { struct queue_limits limits; + unsigned int required_elevator_features; + #ifdef CONFIG_BLK_DEV_ZONED /* * Zoned block device information for request dispatch control. @@ -1097,6 +1099,8 @@ extern void blk_queue_dma_alignment(struct request_queue *, int); extern void blk_queue_update_dma_alignment(struct request_queue *, int); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua); +extern void blk_queue_required_elevator_features(struct request_queue *q, + unsigned int features); /* * Number of physical segments as sent to the device. diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 1dd014c9c87b..901bda352dcb 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -76,6 +76,7 @@ struct elevator_type struct elv_fs_entry *elevator_attrs; const char *elevator_name; const char *elevator_alias; + const unsigned int elevator_features; struct module *elevator_owner; #ifdef CONFIG_BLK_DEBUG_FS const struct blk_mq_debugfs_attr *queue_debugfs_attrs; @@ -165,5 +166,12 @@ extern struct request *elv_rb_find(struct rb_root *, sector_t); #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) #define rq_fifo_clear(rq) list_del_init(&(rq)->queuelist) +/* + * Elevator features. + */ + +/* Supports zoned block devices sequential write constraint */ +#define ELEVATOR_F_ZBD_SEQ_WRITE (1U << 0) + #endif /* CONFIG_BLOCK */ #endif |