Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 184f999e authored by David Sterba's avatar David Sterba
Browse files

btrfs: add helper to initialize the non-bio part of btrfs_io_bio 



We use btrfs_bioset for bios and ask to allocate the entire size of
btrfs_io_bio from btrfs bio_alloc_bioset. The member 'bio' is
initialized but the bytes from 0 to offset of 'bio' are left
uninitialized. Although we initialize some of the members in our
helpers, we should initialize the whole structures.

Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent fa1bcbe0

fs/btrfs/extent_io.c

+14 −16
Original line number Diff line number Diff line
@@ -2653,6 +2653,16 @@ static void end_bio_extent_readpage(struct bio *bio) 
	bio_put(bio);

}



/*

 * Initialize the members up to but not including 'bio'. Use after allocating a

 * new bio by bio_alloc_bioset as it does not initialize the bytes outside of

 * 'bio' because use of __GFP_ZERO is not supported.

 */

static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)

{

	memset(btrfs_bio, 0, offsetof(struct btrfs_io_bio, bio));

}



/*

 * 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
@@ -2660,16 +2670,12 @@ static void end_bio_extent_readpage(struct bio *bio) 
 */

struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)

{

	struct btrfs_io_bio *btrfs_bio;

	struct bio *bio;



	bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, btrfs_bioset);

	bio->bi_bdev = bdev;

	bio->bi_iter.bi_sector = first_byte >> 9;

	btrfs_bio = btrfs_io_bio(bio);

	btrfs_bio->csum = NULL;

	btrfs_bio->csum_allocated = NULL;

	btrfs_bio->end_io = NULL;

	btrfs_io_bio_init(btrfs_io_bio(bio));

	return bio;

}
@@ -2681,24 +2687,18 @@ struct bio *btrfs_bio_clone(struct bio *bio) 
	/* Bio allocation backed by a bioset does not fail */

	new = bio_clone_fast(bio, GFP_NOFS, btrfs_bioset);

	btrfs_bio = btrfs_io_bio(new);

	btrfs_bio->csum = NULL;

	btrfs_bio->csum_allocated = NULL;

	btrfs_bio->end_io = NULL;

	btrfs_io_bio_init(btrfs_bio);

	btrfs_bio->iter = bio->bi_iter;

	return new;

}



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);

	btrfs_bio = btrfs_io_bio(bio);

	btrfs_bio->csum = NULL;

	btrfs_bio->csum_allocated = NULL;

	btrfs_bio->end_io = NULL;

	btrfs_io_bio_init(btrfs_io_bio(bio));

	return bio;

}
@@ -2712,9 +2712,7 @@ struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size) 
	ASSERT(bio);



	btrfs_bio = btrfs_io_bio(bio);

	btrfs_bio->csum = NULL;

	btrfs_bio->csum_allocated = NULL;

	btrfs_bio->end_io = NULL;

	btrfs_io_bio_init(btrfs_bio);



	bio_trim(bio, offset >> 9, size >> 9);

	btrfs_bio->iter = bio->bi_iter;