From 6e707bcd1f71949c7fc0520c388c64aae91b2d77 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 2 Jun 2017 17:26:26 +0200 Subject: [PATCH] btrfs: bioset allocations will never fail, adapt our helpers Christoph pointed out that bio allocations backed by a bioset will never fail. As we always use a bioset for all bio allocations, we can skip the error handling. This patch adjusts our low-level helpers, the cascaded changes to all callers will come next. CC: Liu Bo Reviewed-by: Christoph Hellwig Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 52 +++++++++++++++++--------------------------- 1 file changed, 20 insertions(+), 32 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index da9a02adad22..9ff3e78b9ef1 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2659,8 +2659,9 @@ readpage_ok: } /* - * this allocates from the btrfs_bioset. We're returning a bio right now - * but you can call btrfs_io_bio for the appropriate container_of magic + * The following helpers allocate a bio. As it's backed by a bioset, it'll + * never fail. We're returning a bio right now but you can call btrfs_io_bio + * for the appropriate container_of magic */ struct bio * btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, @@ -2670,22 +2671,12 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, struct bio *bio; bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset); - - if (bio == NULL && (current->flags & PF_MEMALLOC)) { - while (!bio && (nr_vecs /= 2)) { - bio = bio_alloc_bioset(gfp_flags, - nr_vecs, btrfs_bioset); - } - } - - if (bio) { - bio->bi_bdev = bdev; - bio->bi_iter.bi_sector = first_sector; - btrfs_bio = btrfs_io_bio(bio); - btrfs_bio->csum = NULL; - btrfs_bio->csum_allocated = NULL; - btrfs_bio->end_io = NULL; - } + bio->bi_bdev = bdev; + bio->bi_iter.bi_sector = first_sector; + btrfs_bio = btrfs_io_bio(bio); + btrfs_bio->csum = NULL; + btrfs_bio->csum_allocated = NULL; + btrfs_bio->end_io = NULL; return bio; } @@ -2694,30 +2685,27 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) struct btrfs_io_bio *btrfs_bio; struct bio *new; + /* Bio allocation backed by a bioset does not fail */ new = bio_clone_fast(bio, gfp_mask, btrfs_bioset); - if (new) { - btrfs_bio = btrfs_io_bio(new); - btrfs_bio->csum = NULL; - btrfs_bio->csum_allocated = NULL; - btrfs_bio->end_io = NULL; - btrfs_bio->iter = bio->bi_iter; - } + btrfs_bio = btrfs_io_bio(new); + btrfs_bio->csum = NULL; + btrfs_bio->csum_allocated = NULL; + btrfs_bio->end_io = NULL; + btrfs_bio->iter = bio->bi_iter; return new; } -/* this also allocates from the btrfs_bioset */ struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) { struct btrfs_io_bio *btrfs_bio; struct bio *bio; + /* Bio allocation backed by a bioset does not fail */ bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset); - if (bio) { - btrfs_bio = btrfs_io_bio(bio); - btrfs_bio->csum = NULL; - btrfs_bio->csum_allocated = NULL; - btrfs_bio->end_io = NULL; - } + btrfs_bio = btrfs_io_bio(bio); + btrfs_bio->csum = NULL; + btrfs_bio->csum_allocated = NULL; + btrfs_bio->end_io = NULL; return bio; } -- 2.20.1