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-rw-r--r--block/blk-ioc.c62
1 files changed, 17 insertions, 45 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index fb23965595d..e23c797b468 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -205,16 +205,15 @@ void exit_io_context(struct task_struct *task)
put_io_context(ioc, NULL);
}
-static struct io_context *create_task_io_context(struct task_struct *task,
- gfp_t gfp_flags, int node,
- bool take_ref)
+void create_io_context_slowpath(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 NULL;
+ return;
/* initialize */
atomic_long_set(&ioc->refcount, 1);
@@ -226,42 +225,13 @@ static struct io_context *create_task_io_context(struct task_struct *task,
/* try to install, somebody might already have beaten us to it */
task_lock(task);
-
- if (!task->io_context && !(task->flags & PF_EXITING)) {
+ if (!task->io_context && !(task->flags & PF_EXITING))
task->io_context = ioc;
- } else {
+ else
kmem_cache_free(iocontext_cachep, ioc);
- ioc = task->io_context;
- }
-
- if (ioc && take_ref)
- get_io_context(ioc);
-
task_unlock(task);
- return ioc;
}
-
-/**
- * current_io_context - get io_context of %current
- * @gfp_flags: allocation flags, used if allocation is necessary
- * @node: allocation node, used if allocation is necessary
- *
- * Return io_context of %current. If it doesn't exist, it is created with
- * @gfp_flags and @node. The returned io_context does NOT have its
- * reference count incremented. Because io_context is exited only on task
- * exit, %current can be sure that the returned io_context is valid and
- * alive as long as it is executing.
- */
-struct io_context *current_io_context(gfp_t gfp_flags, int node)
-{
- might_sleep_if(gfp_flags & __GFP_WAIT);
-
- if (current->io_context)
- return current->io_context;
-
- return create_task_io_context(current, gfp_flags, node, false);
-}
-EXPORT_SYMBOL(current_io_context);
+EXPORT_SYMBOL(create_io_context_slowpath);
/**
* get_task_io_context - get io_context of a task
@@ -274,7 +244,7 @@ EXPORT_SYMBOL(current_io_context);
* incremented.
*
* This function always goes through task_lock() and it's better to use
- * current_io_context() + get_io_context() for %current.
+ * %current->io_context + get_io_context() for %current.
*/
struct io_context *get_task_io_context(struct task_struct *task,
gfp_t gfp_flags, int node)
@@ -283,16 +253,18 @@ struct io_context *get_task_io_context(struct task_struct *task,
might_sleep_if(gfp_flags & __GFP_WAIT);
- task_lock(task);
- ioc = task->io_context;
- if (likely(ioc)) {
- get_io_context(ioc);
+ do {
+ task_lock(task);
+ ioc = task->io_context;
+ if (likely(ioc)) {
+ get_io_context(ioc);
+ task_unlock(task);
+ return ioc;
+ }
task_unlock(task);
- return ioc;
- }
- task_unlock(task);
+ } while (create_io_context(task, gfp_flags, node));
- return create_task_io_context(task, gfp_flags, node, true);
+ return NULL;
}
EXPORT_SYMBOL(get_task_io_context);