6.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nilay Shroff nilay@linux.ibm.com
[ Upstream commit 04728ce90966c54417fd8120a3820104d18ba68d ]
This patch introduces a new structure, struct elevator_resources, to group together all elevator-related resources that share the same lifetime. As a first step, this change moves the elevator tag pointer from struct elv_change_ctx into the new struct elevator_resources.
Additionally, rename blk_mq_alloc_sched_tags_batch() and blk_mq_free_sched_tags_batch() to blk_mq_alloc_sched_res_batch() and blk_mq_free_sched_res_batch(), respectively. Introduce two new wrapper helpers, blk_mq_alloc_sched_res() and blk_mq_free_sched_res(), around blk_mq_alloc_sched_tags() and blk_mq_free_sched_tags().
These changes pave the way for consolidating the allocation and freeing of elevator-specific resources into common helper functions. This refactoring improves encapsulation and prepares the code for future extensions, allowing additional elevator-specific data to be added to struct elevator_resources without cluttering struct elv_change_ctx.
Subsequent patches will extend struct elevator_resources to include other elevator-related data.
Reviewed-by: Ming Lei ming.lei@redhat.com Reviewed-by: Yu Kuai yukuai@fnnas.com Signed-off-by: Nilay Shroff nilay@linux.ibm.com Signed-off-by: Jens Axboe axboe@kernel.dk Stable-dep-of: 9869d3a6fed3 ("block: fix race between wbt_enable_default and IO submission") Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk-mq-sched.c | 48 ++++++++++++++++++++++++++++++-------------- block/blk-mq-sched.h | 10 ++++++--- block/blk-mq.c | 2 +- block/elevator.c | 31 ++++++++++++++-------------- block/elevator.h | 9 +++++++-- 5 files changed, 64 insertions(+), 36 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 3d9386555a50..03ff16c49976 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -427,7 +427,16 @@ void blk_mq_free_sched_tags(struct elevator_tags *et, kfree(et); }
-void blk_mq_free_sched_tags_batch(struct xarray *elv_tbl, +void blk_mq_free_sched_res(struct elevator_resources *res, + struct blk_mq_tag_set *set) +{ + if (res->et) { + blk_mq_free_sched_tags(res->et, set); + res->et = NULL; + } +} + +void blk_mq_free_sched_res_batch(struct xarray *elv_tbl, struct blk_mq_tag_set *set) { struct request_queue *q; @@ -445,12 +454,11 @@ void blk_mq_free_sched_tags_batch(struct xarray *elv_tbl, */ if (q->elevator) { ctx = xa_load(elv_tbl, q->id); - if (!ctx || !ctx->et) { + if (!ctx) { WARN_ON_ONCE(1); continue; } - blk_mq_free_sched_tags(ctx->et, set); - ctx->et = NULL; + blk_mq_free_sched_res(&ctx->res, set); } } } @@ -532,12 +540,24 @@ struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set, return NULL; }
-int blk_mq_alloc_sched_tags_batch(struct xarray *elv_tbl, +int blk_mq_alloc_sched_res(struct request_queue *q, + struct elevator_resources *res, unsigned int nr_hw_queues) +{ + struct blk_mq_tag_set *set = q->tag_set; + + res->et = blk_mq_alloc_sched_tags(set, nr_hw_queues, + blk_mq_default_nr_requests(set)); + if (!res->et) + return -ENOMEM; + + return 0; +} + +int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl, struct blk_mq_tag_set *set, unsigned int nr_hw_queues) { struct elv_change_ctx *ctx; struct request_queue *q; - struct elevator_tags *et; int ret = -ENOMEM;
lockdep_assert_held_write(&set->update_nr_hwq_lock); @@ -557,11 +577,10 @@ int blk_mq_alloc_sched_tags_batch(struct xarray *elv_tbl, goto out_unwind; }
- ctx->et = blk_mq_alloc_sched_tags(set, nr_hw_queues, - blk_mq_default_nr_requests(set)); - if (!ctx->et) + ret = blk_mq_alloc_sched_res(q, &ctx->res, + nr_hw_queues); + if (ret) goto out_unwind; - } } return 0; @@ -569,10 +588,8 @@ int blk_mq_alloc_sched_tags_batch(struct xarray *elv_tbl, list_for_each_entry_continue_reverse(q, &set->tag_list, tag_set_list) { if (q->elevator) { ctx = xa_load(elv_tbl, q->id); - if (ctx && ctx->et) { - blk_mq_free_sched_tags(ctx->et, set); - ctx->et = NULL; - } + if (ctx) + blk_mq_free_sched_res(&ctx->res, set); } } return ret; @@ -580,9 +597,10 @@ int blk_mq_alloc_sched_tags_batch(struct xarray *elv_tbl,
/* caller must have a reference to @e, will grab another one if successful */ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e, - struct elevator_tags *et) + struct elevator_resources *res) { unsigned int flags = q->tag_set->flags; + struct elevator_tags *et = res->et; struct blk_mq_hw_ctx *hctx; struct elevator_queue *eq; unsigned long i; diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 2fddbc91a235..1f8e58dd4b49 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -19,20 +19,24 @@ void __blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx); void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx);
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e, - struct elevator_tags *et); + struct elevator_resources *res); void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e); void blk_mq_sched_free_rqs(struct request_queue *q);
struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set, unsigned int nr_hw_queues, unsigned int nr_requests); -int blk_mq_alloc_sched_tags_batch(struct xarray *et_table, +int blk_mq_alloc_sched_res(struct request_queue *q, + struct elevator_resources *res, unsigned int nr_hw_queues); +int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl, struct blk_mq_tag_set *set, unsigned int nr_hw_queues); int blk_mq_alloc_sched_ctx_batch(struct xarray *elv_tbl, struct blk_mq_tag_set *set); void blk_mq_free_sched_ctx_batch(struct xarray *elv_tbl); void blk_mq_free_sched_tags(struct elevator_tags *et, struct blk_mq_tag_set *set); -void blk_mq_free_sched_tags_batch(struct xarray *et_table, +void blk_mq_free_sched_res(struct elevator_resources *res, + struct blk_mq_tag_set *set); +void blk_mq_free_sched_res_batch(struct xarray *et_table, struct blk_mq_tag_set *set);
static inline void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx) diff --git a/block/blk-mq.c b/block/blk-mq.c index 180d45db5624..ea5f948af7a4 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -5079,7 +5079,7 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, if (blk_mq_alloc_sched_ctx_batch(&elv_tbl, set) < 0) goto out_free_ctx;
- if (blk_mq_alloc_sched_tags_batch(&elv_tbl, set, nr_hw_queues) < 0) + if (blk_mq_alloc_sched_res_batch(&elv_tbl, set, nr_hw_queues) < 0) goto out_free_ctx;
list_for_each_entry(q, &set->tag_list, tag_set_list) { diff --git a/block/elevator.c b/block/elevator.c index cd7bdff205c8..cbec292a4af5 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -580,7 +580,7 @@ static int elevator_switch(struct request_queue *q, struct elv_change_ctx *ctx) }
if (new_e) { - ret = blk_mq_init_sched(q, new_e, ctx->et); + ret = blk_mq_init_sched(q, new_e, &ctx->res); if (ret) goto out_unfreeze; ctx->new = q->elevator; @@ -604,7 +604,8 @@ static int elevator_switch(struct request_queue *q, struct elv_change_ctx *ctx) return ret; }
-static void elv_exit_and_release(struct request_queue *q) +static void elv_exit_and_release(struct elv_change_ctx *ctx, + struct request_queue *q) { struct elevator_queue *e; unsigned memflags; @@ -616,7 +617,7 @@ static void elv_exit_and_release(struct request_queue *q) mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); if (e) { - blk_mq_free_sched_tags(e->et, q->tag_set); + blk_mq_free_sched_res(&ctx->res, q->tag_set); kobject_put(&e->kobj); } } @@ -627,11 +628,12 @@ static int elevator_change_done(struct request_queue *q, int ret = 0;
if (ctx->old) { + struct elevator_resources res = {.et = ctx->old->et}; bool enable_wbt = test_bit(ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT, &ctx->old->flags);
elv_unregister_queue(q, ctx->old); - blk_mq_free_sched_tags(ctx->old->et, q->tag_set); + blk_mq_free_sched_res(&res, q->tag_set); kobject_put(&ctx->old->kobj); if (enable_wbt) wbt_enable_default(q->disk); @@ -639,7 +641,7 @@ static int elevator_change_done(struct request_queue *q, if (ctx->new) { ret = elv_register_queue(q, ctx->new, !ctx->no_uevent); if (ret) - elv_exit_and_release(q); + elv_exit_and_release(ctx, q); } return ret; } @@ -656,10 +658,9 @@ static int elevator_change(struct request_queue *q, struct elv_change_ctx *ctx) lockdep_assert_held(&set->update_nr_hwq_lock);
if (strncmp(ctx->name, "none", 4)) { - ctx->et = blk_mq_alloc_sched_tags(set, set->nr_hw_queues, - blk_mq_default_nr_requests(set)); - if (!ctx->et) - return -ENOMEM; + ret = blk_mq_alloc_sched_res(q, &ctx->res, set->nr_hw_queues); + if (ret) + return ret; }
memflags = blk_mq_freeze_queue(q); @@ -681,10 +682,10 @@ static int elevator_change(struct request_queue *q, struct elv_change_ctx *ctx) if (!ret) ret = elevator_change_done(q, ctx); /* - * Free sched tags if it's allocated but we couldn't switch elevator. + * Free sched resource if it's allocated but we couldn't switch elevator. */ - if (ctx->et && !ctx->new) - blk_mq_free_sched_tags(ctx->et, set); + if (!ctx->new) + blk_mq_free_sched_res(&ctx->res, set);
return ret; } @@ -711,10 +712,10 @@ void elv_update_nr_hw_queues(struct request_queue *q, if (!ret) WARN_ON_ONCE(elevator_change_done(q, ctx)); /* - * Free sched tags if it's allocated but we couldn't switch elevator. + * Free sched resource if it's allocated but we couldn't switch elevator. */ - if (ctx->et && !ctx->new) - blk_mq_free_sched_tags(ctx->et, set); + if (!ctx->new) + blk_mq_free_sched_res(&ctx->res, set); }
/* diff --git a/block/elevator.h b/block/elevator.h index bad43182361e..621a63597249 100644 --- a/block/elevator.h +++ b/block/elevator.h @@ -32,6 +32,11 @@ struct elevator_tags { struct blk_mq_tags *tags[]; };
+struct elevator_resources { + /* holds elevator tags */ + struct elevator_tags *et; +}; + /* Holding context data for changing elevator */ struct elv_change_ctx { const char *name; @@ -43,8 +48,8 @@ struct elv_change_ctx { struct elevator_queue *new; /* store elevator type */ struct elevator_type *type; - /* holds sched tags data */ - struct elevator_tags *et; + /* store elevator resources */ + struct elevator_resources res; };
struct elevator_mq_ops {