Commit d5f68a42 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

fs: remove mpage_alloc 



open code mpage_alloc in it's two callers and simplify the results
because of the context:

 - __mpage_writepage always passes GFP_NOFS and can thus always sleep and
    will never get a NULL return from bio_alloc at all.
 - do_mpage_readpage can only get a non-sleeping context for readahead
   which never sets PF_MEMALLOC and thus doesn't need the retry loop
   either.

Both cases will never have __GFP_HIGH set.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-2-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 322cbb50

fs/mpage.c

+6 −29
Original line number Diff line number Diff line
@@ -66,29 +66,6 @@ static struct bio *mpage_bio_submit(int op, int op_flags, struct bio *bio) 
	return NULL;

}



static struct bio *

mpage_alloc(struct block_device *bdev,

		sector_t first_sector, int nr_vecs,

		gfp_t gfp_flags)

{

	struct bio *bio;



	/* Restrict the given (page cache) mask for slab allocations */

	gfp_flags &= GFP_KERNEL;

	bio = bio_alloc(gfp_flags, nr_vecs);



	if (bio == NULL && (current->flags & PF_MEMALLOC)) {

		while (!bio && (nr_vecs /= 2))

			bio = bio_alloc(gfp_flags, nr_vecs);

	}



	if (bio) {

		bio_set_dev(bio, bdev);

		bio->bi_iter.bi_sector = first_sector;

	}

	return bio;

}



/*

 * support function for mpage_readahead.  The fs supplied get_block might

 * return an up to date buffer.  This is used to map that buffer into
@@ -296,10 +273,11 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
								page))

				goto out;

		}

		args->bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9),

					bio_max_segs(args->nr_pages), gfp);

		args->bio = bio_alloc(gfp, bio_max_segs(args->nr_pages));

		if (args->bio == NULL)

			goto confused;

		bio_set_dev(args->bio, bdev);

		args->bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);

	}



	length = first_hole << blkbits;
@@ -608,10 +586,9 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc, 
								page, wbc))

				goto out;

		}

		bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9),

				BIO_MAX_VECS, GFP_NOFS|__GFP_HIGH);

		if (bio == NULL)

			goto confused;

		bio = bio_alloc(GFP_NOFS, BIO_MAX_VECS);

		bio_set_dev(bio, bdev);

		bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);



		wbc_init_bio(wbc, bio);

		bio->bi_write_hint = inode->i_write_hint;