diff options
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 165 |
1 files changed, 16 insertions, 149 deletions
diff --git a/block/bio.c b/block/bio.c index a7366c02c9b5..c63ba04bd629 100644 --- a/block/bio.c +++ b/block/bio.c @@ -234,8 +234,12 @@ fallback: void bio_uninit(struct bio *bio) { - bio_disassociate_blkg(bio); - +#ifdef CONFIG_BLK_CGROUP + if (bio->bi_blkg) { + blkg_put(bio->bi_blkg); + bio->bi_blkg = NULL; + } +#endif if (bio_integrity(bio)) bio_integrity_free(bio); @@ -354,7 +358,7 @@ static void bio_alloc_rescue(struct work_struct *work) if (!bio) break; - generic_make_request(bio); + submit_bio_noacct(bio); } } @@ -412,19 +416,19 @@ static void punt_bios_to_rescuer(struct bio_set *bs) * submit the previously allocated bio for IO before attempting to allocate * a new one. Failure to do so can cause deadlocks under memory pressure. * - * Note that when running under generic_make_request() (i.e. any block + * Note that when running under submit_bio_noacct() (i.e. any block * driver), bios are not submitted until after you return - see the code in - * generic_make_request() that converts recursion into iteration, to prevent + * submit_bio_noacct() that converts recursion into iteration, to prevent * stack overflows. * * This would normally mean allocating multiple bios under - * generic_make_request() would be susceptible to deadlocks, but we have + * submit_bio_noacct() would be susceptible to deadlocks, but we have * deadlock avoidance code that resubmits any blocked bios from a rescuer * thread. * * However, we do not guarantee forward progress for allocations from other * mempools. Doing multiple allocations from the same mempool under - * generic_make_request() should be avoided - instead, use bio_set's front_pad + * submit_bio_noacct() should be avoided - instead, use bio_set's front_pad * for per bio allocations. * * RETURNS: @@ -444,9 +448,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs, if (nr_iovecs > UIO_MAXIOV) return NULL; - p = kmalloc(sizeof(struct bio) + - nr_iovecs * sizeof(struct bio_vec), - gfp_mask); + p = kmalloc(struct_size(bio, bi_inline_vecs, nr_iovecs), gfp_mask); front_pad = 0; inline_vecs = nr_iovecs; } else { @@ -455,14 +457,14 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs, nr_iovecs > 0)) return NULL; /* - * generic_make_request() converts recursion to iteration; this + * submit_bio_noacct() converts recursion to iteration; this * means if we're running beneath it, any bios we allocate and * submit will not be submitted (and thus freed) until after we * return. * * This exposes us to a potential deadlock if we allocate * multiple bios from the same bio_set() while running - * underneath generic_make_request(). If we were to allocate + * underneath submit_bio_noacct(). If we were to allocate * multiple bios (say a stacking block driver that was splitting * bios), we would deadlock if we exhausted the mempool's * reserve. @@ -860,7 +862,7 @@ EXPORT_SYMBOL(bio_add_pc_page); * @same_page: return if the segment has been merged inside the same page * * Try to add the data at @page + @off to the last bvec of @bio. This is a - * a useful optimisation for file systems with a block size smaller than the + * useful optimisation for file systems with a block size smaller than the * page size. * * Warn if (@len, @off) crosses pages in case that @same_page is true. @@ -986,7 +988,7 @@ static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) * Pins pages from *iter and appends them to @bio's bvec array. The * pages will have to be released using put_page() when done. * For multi-segment *iter, this function only adds pages from the - * the next non-empty segment of the iov iterator. + * next non-empty segment of the iov iterator. */ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { @@ -1625,141 +1627,6 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) } EXPORT_SYMBOL(bioset_init_from_src); -#ifdef CONFIG_BLK_CGROUP - -/** - * bio_disassociate_blkg - puts back the blkg reference if associated - * @bio: target bio - * - * Helper to disassociate the blkg from @bio if a blkg is associated. - */ -void bio_disassociate_blkg(struct bio *bio) -{ - if (bio->bi_blkg) { - blkg_put(bio->bi_blkg); - bio->bi_blkg = NULL; - } -} -EXPORT_SYMBOL_GPL(bio_disassociate_blkg); - -/** - * __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. - */ -static void __bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) -{ - bio_disassociate_blkg(bio); - - bio->bi_blkg = blkg_tryget_closest(blkg); -} - -/** - * 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. - */ -void 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; - - rcu_read_lock(); - - if (!css || !css->parent) - blkg = q->root_blkg; - else - blkg = blkg_lookup_create(css_to_blkcg(css), q); - - __bio_associate_blkg(bio, blkg); - - rcu_read_unlock(); -} -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: 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. - */ -void bio_associate_blkg_from_page(struct bio *bio, struct page *page) -{ - struct cgroup_subsys_state *css; - - if (!page->mem_cgroup) - return; - - rcu_read_lock(); - - css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); - bio_associate_blkg_from_css(bio, css); - - rcu_read_unlock(); -} -#endif /* CONFIG_MEMCG */ - -/** - * bio_associate_blkg - associate a bio with a blkg - * @bio: target bio - * - * Associate @bio with the blkg found from the bio's css and request_queue. - * If one is not found, bio_lookup_blkg() creates the blkg. If a blkg is - * already associated, the css is reused and association redone as the - * request_queue may have changed. - */ -void bio_associate_blkg(struct bio *bio) -{ - struct cgroup_subsys_state *css; - - rcu_read_lock(); - - if (bio->bi_blkg) - css = &bio_blkcg(bio)->css; - else - css = blkcg_css(); - - bio_associate_blkg_from_css(bio, css); - - rcu_read_unlock(); -} -EXPORT_SYMBOL_GPL(bio_associate_blkg); - -/** - * bio_clone_blkg_association - clone blkg association from src to dst bio - * @dst: destination bio - * @src: source bio - */ -void bio_clone_blkg_association(struct bio *dst, struct bio *src) -{ - rcu_read_lock(); - - if (src->bi_blkg) - __bio_associate_blkg(dst, src->bi_blkg); - - rcu_read_unlock(); -} -EXPORT_SYMBOL_GPL(bio_clone_blkg_association); -#endif /* CONFIG_BLK_CGROUP */ - static void __init biovec_init_slabs(void) { int i; |