[PATCH v2] block: remove create_io_context

[PATCH v2] block: remove create_io_context

[Christoph Hellwig]

create_io_context just has a single caller, which also happens to not
even use the return value.  Just open code it there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---

Changes since v1:

 - add a commit log

 block/blk-core.c | 11 ++++++-----
 block/blk.h      | 20 --------------------
 2 files changed, 6 insertions(+), 25 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 311596d5dbc41..38e984d95e84b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -963,12 +963,13 @@ generic_make_request_checks(struct bio *bio)
 	}
 
 	/*
-	 * Various block parts want %current->io_context and lazy ioc
-	 * allocation ends up trading a lot of pain for a small amount of
-	 * memory.  Just allocate it upfront.  This may fail and block
-	 * layer knows how to live with it.
+	 * Various block parts want %current->io_context, so allocate it up
+	 * front rather than dealing with lots of pain to allocate it only
+	 * where needed. This may fail and the block layer knows how to live
+	 * with it.
 	 */
-	create_io_context(GFP_ATOMIC, q->node);
+	if (unlikely(!current->io_context))
+		create_task_io_context(current, GFP_ATOMIC, q->node);
 
 	if (!blkcg_bio_issue_check(q, bio))
 		return false;
diff --git a/block/blk.h b/block/blk.h
index 204963bb03e89..73bd3b1c69384 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -303,26 +303,6 @@ void ioc_clear_queue(struct request_queue *q);
 
 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
 
-/**
- * create_io_context - try to create task->io_context
- * @gfp_mask: allocation mask
- * @node: allocation node
- *
- * 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 %current->io_context is IRQ-unsafe.
- */
-static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
-{
-	WARN_ON_ONCE(irqs_disabled());
-	if (unlikely(!current->io_context))
-		create_task_io_context(current, gfp_mask, node);
-	return current->io_context;
-}
-
 /*
  * Internal throttling interface
  */
-- 
2.26.1

Re: [PATCH v2] block: remove create_io_context

[Jens Axboe]

On 4/25/20 1:55 AM, Christoph Hellwig wrote:
> create_io_context just has a single caller, which also happens to not
> even use the return value.  Just open code it there.

Applied, thanks.

-- 
Jens Axboe