#include <linux/swap.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
+#include <linux/iocontext.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/mempool.h>
#include <linux/workqueue.h>
+#include <linux/cgroup.h>
#include <scsi/sg.h> /* for struct sg_iovec */
#include <trace/events/block.h>
{
unsigned int sz = sizeof(struct bio) + extra_size;
struct kmem_cache *slab = NULL;
- struct bio_slab *bslab;
+ struct bio_slab *bslab, *new_bio_slabs;
unsigned int i, entry = -1;
mutex_lock(&bio_slab_lock);
if (bio_slab_nr == bio_slab_max && entry == -1) {
bio_slab_max <<= 1;
- bio_slabs = krealloc(bio_slabs,
- bio_slab_max * sizeof(struct bio_slab),
- GFP_KERNEL);
- if (!bio_slabs)
+ new_bio_slabs = krealloc(bio_slabs,
+ bio_slab_max * sizeof(struct bio_slab),
+ GFP_KERNEL);
+ if (!new_bio_slabs)
goto out_unlock;
+ bio_slabs = new_bio_slabs;
}
if (entry == -1)
entry = bio_slab_nr++;
* last put frees it
*/
if (atomic_dec_and_test(&bio->bi_cnt)) {
+ bio_disassociate_task(bio);
bio->bi_next = NULL;
bio->bi_destructor(bio);
}
* Note that this code is very hard to test under normal circumstances because
* direct-io pins the pages with get_user_pages(). This makes
* is_page_cache_freeable return false, and the VM will not clean the pages.
- * But other code (eg, pdflush) could clean the pages if they are mapped
+ * But other code (eg, flusher threads) could clean the pages if they are mapped
* pagecache.
*
* Simply disabling the call to bio_set_pages_dirty() is a good way to test the
}
EXPORT_SYMBOL(bioset_create);
+#ifdef CONFIG_BLK_CGROUP
+/**
+ * bio_associate_current - associate a bio with %current
+ * @bio: target bio
+ *
+ * Associate @bio with %current if it hasn't been associated yet. Block
+ * layer will treat @bio as if it were issued by %current no matter which
+ * task actually issues it.
+ *
+ * This function takes an extra reference of @task's io_context and blkcg
+ * which will be put when @bio is released. The caller must own @bio,
+ * ensure %current->io_context exists, and is responsible for synchronizing
+ * calls to this function.
+ */
+int bio_associate_current(struct bio *bio)
+{
+ struct io_context *ioc;
+ struct cgroup_subsys_state *css;
+
+ if (bio->bi_ioc)
+ return -EBUSY;
+
+ ioc = current->io_context;
+ if (!ioc)
+ return -ENOENT;
+
+ /* acquire active ref on @ioc and associate */
+ get_io_context_active(ioc);
+ bio->bi_ioc = ioc;
+
+ /* associate blkcg if exists */
+ rcu_read_lock();
+ css = task_subsys_state(current, blkio_subsys_id);
+ if (css && css_tryget(css))
+ bio->bi_css = css;
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/**
+ * bio_disassociate_task - undo bio_associate_current()
+ * @bio: target bio
+ */
+void bio_disassociate_task(struct bio *bio)
+{
+ if (bio->bi_ioc) {
+ put_io_context(bio->bi_ioc);
+ bio->bi_ioc = NULL;
+ }
+ if (bio->bi_css) {
+ css_put(bio->bi_css);
+ bio->bi_css = NULL;
+ }
+}
+
+#endif /* CONFIG_BLK_CGROUP */
+
static void __init biovec_init_slabs(void)
{
int i;