From 24acfc34fba0b4f62ef9d5c2616eb0faa802b606 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 5 Mar 2012 13:15:24 -0800 Subject: [PATCH] block: interface update for ioc/icq creation functions Make the following interface updates to prepare for future ioc related changes. * create_io_context() returning ioc only works for %current because it doesn't increment ref on the ioc. Drop @task parameter from it and always assume %current. * Make create_io_context_slowpath() return 0 or -errno and rename it to create_task_io_context(). * Make ioc_create_icq() take @ioc as parameter instead of assuming that of %current. The caller, get_request(), is updated to create ioc explicitly and then pass it into ioc_create_icq(). Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-core.c | 8 +++++--- block/blk-ioc.c | 22 ++++++++++------------ block/blk.h | 24 +++++++++++------------- 3 files changed, 26 insertions(+), 28 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 792a384a8e35..b2d0fcd8f87f 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -855,7 +855,7 @@ retry: */ if (!ioc && !retried) { spin_unlock_irq(q->queue_lock); - create_io_context(current, gfp_mask, q->node); + create_io_context(gfp_mask, q->node); spin_lock_irq(q->queue_lock); retried = true; goto retry; @@ -919,7 +919,9 @@ retry: /* create icq if missing */ if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) { - icq = ioc_create_icq(q, gfp_mask); + ioc = create_io_context(gfp_mask, q->node); + if (ioc) + icq = ioc_create_icq(ioc, q, gfp_mask); if (!icq) goto fail_alloc; } @@ -1005,7 +1007,7 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags, * up to a big batch of them for a small period time. * See ioc_batching, ioc_set_batching */ - create_io_context(current, GFP_NOIO, q->node); + create_io_context(GFP_NOIO, q->node); ioc_set_batching(q, current->io_context); spin_lock_irq(q->queue_lock); diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 92bf55540d87..10928740b5da 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -212,15 +212,14 @@ void ioc_clear_queue(struct request_queue *q) } } -void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_flags, - int node) +int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node) { struct io_context *ioc; ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags | __GFP_ZERO, node); if (unlikely(!ioc)) - return; + return -ENOMEM; /* initialize */ atomic_long_set(&ioc->refcount, 1); @@ -244,6 +243,8 @@ void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_flags, else kmem_cache_free(iocontext_cachep, ioc); task_unlock(task); + + return 0; } /** @@ -275,7 +276,7 @@ struct io_context *get_task_io_context(struct task_struct *task, return ioc; } task_unlock(task); - } while (create_io_context(task, gfp_flags, node)); + } while (!create_task_io_context(task, gfp_flags, node)); return NULL; } @@ -319,26 +320,23 @@ EXPORT_SYMBOL(ioc_lookup_icq); /** * ioc_create_icq - create and link io_cq + * @ioc: io_context of interest * @q: request_queue of interest * @gfp_mask: allocation mask * - * Make sure io_cq linking %current->io_context and @q exists. If either - * io_context and/or icq don't exist, they will be created using @gfp_mask. + * Make sure io_cq linking @ioc and @q exists. If icq doesn't exist, they + * will be created using @gfp_mask. * * The caller is responsible for ensuring @ioc won't go away and @q is * alive and will stay alive until this function returns. */ -struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask) +struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, + gfp_t gfp_mask) { struct elevator_type *et = q->elevator->type; - struct io_context *ioc; struct io_cq *icq; /* allocate stuff */ - ioc = create_io_context(current, gfp_mask, q->node); - if (!ioc) - return NULL; - icq = kmem_cache_alloc_node(et->icq_cache, gfp_mask | __GFP_ZERO, q->node); if (!icq) diff --git a/block/blk.h b/block/blk.h index de15f920b38f..aa81afde8220 100644 --- a/block/blk.h +++ b/block/blk.h @@ -200,32 +200,30 @@ static inline int blk_do_io_stat(struct request *rq) */ void get_io_context(struct io_context *ioc); struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); -struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask); +struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, + gfp_t gfp_mask); void ioc_clear_queue(struct request_queue *q); -void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_mask, - int node); +int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); /** * create_io_context - try to create task->io_context - * @task: target task * @gfp_mask: allocation mask * @node: allocation node * - * If @task->io_context is %NULL, allocate a new io_context and install it. - * Returns the current @task->io_context which may be %NULL if allocation - * failed. + * If %current->io_context is %NULL, allocate a new io_context and install + * it. Returns the current %current->io_context which may be %NULL if + * allocation failed. * * Note that this function can't be called with IRQ disabled because - * task_lock which protects @task->io_context is IRQ-unsafe. + * task_lock which protects %current->io_context is IRQ-unsafe. */ -static inline struct io_context *create_io_context(struct task_struct *task, - gfp_t gfp_mask, int node) +static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) { WARN_ON_ONCE(irqs_disabled()); - if (unlikely(!task->io_context)) - create_io_context_slowpath(task, gfp_mask, node); - return task->io_context; + if (unlikely(!current->io_context)) + create_task_io_context(current, gfp_mask, node); + return current->io_context; } /*