bio->bi_iter = bio_src->bi_iter;
bio->bi_io_vec = bio_src->bi_io_vec;
- bio_clone_blkg_association(bio, bio_src);
-
- blkcg_bio_issue_init(bio);
+ bio_clone_blkcg_association(bio, bio_src);
}
EXPORT_SYMBOL(__bio_clone_fast);
/*
* success
*/
- if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||
+ if ((iov_iter_rw(iter) == WRITE && (!map_data || !map_data->null_mapped)) ||
(map_data && map_data->from_user)) {
ret = bio_copy_from_iter(bio, iter);
if (ret)
#ifdef CONFIG_BLK_CGROUP
-/**
- * bio_associate_blkg - associate a bio with the a blkg
- * @bio: target bio
- * @blkg: the blkg to associate
- *
- * This tries to associate @bio with the specified blkg. Association failure
- * is handled by walking up the blkg tree. Therefore, the blkg associated can
- * be anything between @blkg and the root_blkg. This situation only happens
- * when a cgroup is dying and then the remaining bios will spill to the closest
- * alive blkg.
- *
- * A reference will be taken on the @blkg and will be released when @bio is
- * freed.
- */
-int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
-{
- if (unlikely(bio->bi_blkg))
- return -EBUSY;
- bio->bi_blkg = blkg_tryget_closest(blkg);
- return 0;
-}
-
-/**
- * __bio_associate_blkg_from_css - internal blkg association function
- *
- * This in the core association function that all association paths rely on.
- * A blkg reference is taken which is released upon freeing of the bio.
- */
-static int __bio_associate_blkg_from_css(struct bio *bio,
- struct cgroup_subsys_state *css)
-{
- struct request_queue *q = bio->bi_disk->queue;
- struct blkcg_gq *blkg;
- int ret;
-
- rcu_read_lock();
-
- if (!css || !css->parent)
- blkg = q->root_blkg;
- else
- blkg = blkg_lookup_create(css_to_blkcg(css), q);
-
- ret = bio_associate_blkg(bio, blkg);
-
- rcu_read_unlock();
- return ret;
-}
-
-/**
- * bio_associate_blkg_from_css - associate a bio with a specified css
- * @bio: target bio
- * @css: target css
- *
- * Associate @bio with the blkg found by combining the css's blkg and the
- * request_queue of the @bio. This falls back to the queue's root_blkg if
- * the association fails with the css.
- */
-int bio_associate_blkg_from_css(struct bio *bio,
- struct cgroup_subsys_state *css)
-{
- if (unlikely(bio->bi_blkg))
- return -EBUSY;
- return __bio_associate_blkg_from_css(bio, css);
-}
-EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
-
#ifdef CONFIG_MEMCG
/**
- * bio_associate_blkg_from_page - associate a bio with the page's blkg
+ * bio_associate_blkcg_from_page - associate a bio with the page's blkcg
* @bio: target bio
* @page: the page to lookup the blkcg from
*
- * Associate @bio with the blkg from @page's owning memcg and the respective
- * request_queue. If cgroup_e_css returns NULL, fall back to the queue's
- * root_blkg.
- *
- * Note: this must be called after bio has an associated device.
+ * Associate @bio with the blkcg from @page's owning memcg. This works like
+ * every other associate function wrt references.
*/
-int bio_associate_blkg_from_page(struct bio *bio, struct page *page)
+int bio_associate_blkcg_from_page(struct bio *bio, struct page *page)
{
- struct cgroup_subsys_state *css;
- int ret;
+ struct cgroup_subsys_state *blkcg_css;
- if (unlikely(bio->bi_blkg))
+ if (unlikely(bio->bi_css))
return -EBUSY;
if (!page->mem_cgroup)
return 0;
-
- rcu_read_lock();
-
- css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys);
-
- ret = __bio_associate_blkg_from_css(bio, css);
-
- rcu_read_unlock();
- return ret;
+ blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup,
+ &io_cgrp_subsys);
+ bio->bi_css = blkcg_css;
+ return 0;
}
#endif /* CONFIG_MEMCG */
/**
- * bio_associate_create_blkg - associate a bio with a blkg from q
- * @q: request_queue where bio is going
+ * bio_associate_blkcg - associate a bio with the specified blkcg
* @bio: target bio
+ * @blkcg_css: css of the blkcg to associate
+ *
+ * Associate @bio with the blkcg specified by @blkcg_css. Block layer will
+ * treat @bio as if it were issued by a task which belongs to the blkcg.
*
- * Associate @bio with the blkg found from the bio's css and the request_queue.
- * If one is not found, bio_lookup_blkg creates the blkg. This falls back to
- * the queue's root_blkg if association fails.
+ * This function takes an extra reference of @blkcg_css which will be put
+ * when @bio is released. The caller must own @bio and is responsible for
+ * synchronizing calls to this function.
*/
-int bio_associate_create_blkg(struct request_queue *q, struct bio *bio)
+int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css)
{
- struct cgroup_subsys_state *css;
- int ret = 0;
-
- /* someone has already associated this bio with a blkg */
- if (bio->bi_blkg)
- return ret;
-
- rcu_read_lock();
-
- css = blkcg_css();
-
- ret = __bio_associate_blkg_from_css(bio, css);
-
- rcu_read_unlock();
- return ret;
+ if (unlikely(bio->bi_css))
+ return -EBUSY;
+ css_get(blkcg_css);
+ bio->bi_css = blkcg_css;
+ return 0;
}
+EXPORT_SYMBOL_GPL(bio_associate_blkcg);
/**
- * bio_reassociate_blkg - reassociate a bio with a blkg from q
- * @q: request_queue where bio is going
+ * bio_associate_blkg - associate a bio with the specified blkg
* @bio: target bio
+ * @blkg: the blkg to associate
*
- * When submitting a bio, multiple recursive calls to make_request() may occur.
- * This causes the initial associate done in blkcg_bio_issue_check() to be
- * incorrect and reference the prior request_queue. This performs reassociation
- * when this situation happens.
+ * Associate @bio with the blkg specified by @blkg. This is the queue specific
+ * blkcg information associated with the @bio, a reference will be taken on the
+ * @blkg and will be freed when the bio is freed.
*/
-int bio_reassociate_blkg(struct request_queue *q, struct bio *bio)
+int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
{
- if (bio->bi_blkg) {
- blkg_put(bio->bi_blkg);
- bio->bi_blkg = NULL;
- }
-
- return bio_associate_create_blkg(q, bio);
+ if (unlikely(bio->bi_blkg))
+ return -EBUSY;
+ if (!blkg_try_get(blkg))
+ return -ENODEV;
+ bio->bi_blkg = blkg;
+ return 0;
}
/**
put_io_context(bio->bi_ioc);
bio->bi_ioc = NULL;
}
+ if (bio->bi_css) {
+ css_put(bio->bi_css);
+ bio->bi_css = NULL;
+ }
if (bio->bi_blkg) {
blkg_put(bio->bi_blkg);
bio->bi_blkg = NULL;
}
/**
- * bio_clone_blkg_association - clone blkg association from src to dst bio
+ * bio_clone_blkcg_association - clone blkcg association from src to dst bio
* @dst: destination bio
* @src: source bio
*/
-void bio_clone_blkg_association(struct bio *dst, struct bio *src)
+void bio_clone_blkcg_association(struct bio *dst, struct bio *src)
{
- if (src->bi_blkg)
- bio_associate_blkg(dst, src->bi_blkg);
+ if (src->bi_css)
+ WARN_ON(bio_associate_blkcg(dst, src->bi_css));
}
-EXPORT_SYMBOL_GPL(bio_clone_blkg_association);
+EXPORT_SYMBOL_GPL(bio_clone_blkcg_association);
#endif /* CONFIG_BLK_CGROUP */
static void __init biovec_init_slabs(void)
projects / linux-2.6-block.git / blobdiff