Re: [PATCH v2 2/3] btrfs: remove btrfs_bio_alloc() helper
From: David Sterba <hidden>
Date: 2021-09-14 16:45:57
On Tue, Sep 14, 2021 at 09:25:42AM +0800, Qu Wenruo wrote:
quoted hunk ↗ jump to hunk
comp_bio->bi_end_io = end_compressed_bio_read;diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 1aed03ef5f49..5ef7c506aee6 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c@@ -3121,16 +3121,19 @@ static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio) } /* - * The following helpers allocate a bio. As it's backed by a bioset, it'll - * never fail.
This note should stay, it's not obvious why we don't need to handle the allocation failure.
We're returning a bio right now but you can call btrfs_io_bio - * for the appropriate container_of magic + * Allocate a btrfs_io_bio, with @nr_iovecs as maxinum iovecs.
maximum
+ *
+ * If @nr_iovecs is 0, it will use BIO_MAX_VECS as @nr_iovces instead.
+ * This behavior is to provide a fail-safe default value.
*/
-struct bio *btrfs_bio_alloc(u64 first_byte)
+struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
{
struct bio *bio;
- bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_VECS, &btrfs_bioset);
- bio->bi_iter.bi_sector = first_byte >> 9;
+ ASSERT(nr_iovecs <= BIO_MAX_VECS);
+ if (nr_iovecs == 0)
+ nr_iovecs = BIO_MAX_VECS;
+ bio = bio_alloc_bioset(GFP_NOFS, nr_iovecs, &btrfs_bioset);
btrfs_io_bio_init(btrfs_io_bio(bio));
return bio;
}