Commit fd5fe253 authored by Eric Biggers's avatar Eric Biggers Committed by Theodore Ts'o
Browse files

ext4: remove unneeded check for error allocating bio_post_read_ctx 



Since allocating an object from a mempool never fails when
__GFP_DIRECT_RECLAIM (which is included in GFP_NOFS) is set, the check
for failure to allocate a bio_post_read_ctx is unnecessary.  Remove it.

Also remove the redundant assignment to ->bi_private.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231181256.47770-1-ebiggers@kernel.org


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 68e45330

fs/ext4/readpage.c

+8 −17
Original line number Diff line number Diff line
@@ -189,12 +189,11 @@ static inline bool ext4_need_verity(const struct inode *inode, pgoff_t idx) 
	       idx < DIV_ROUND_UP(inode->i_size, PAGE_SIZE);

}



static struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode,

						       struct bio *bio,

static void ext4_set_bio_post_read_ctx(struct bio *bio,

				       const struct inode *inode,

				       pgoff_t first_idx)

{

	unsigned int post_read_steps = 0;

	struct bio_post_read_ctx *ctx = NULL;



	if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))

		post_read_steps |= 1 << STEP_DECRYPT;
@@ -203,14 +202,14 @@ static struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode, 
		post_read_steps |= 1 << STEP_VERITY;



	if (post_read_steps) {

		ctx = mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);

		if (!ctx)

			return ERR_PTR(-ENOMEM);

		/* Due to the mempool, this never fails. */

		struct bio_post_read_ctx *ctx =

			mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);



		ctx->bio = bio;

		ctx->enabled_steps = post_read_steps;

		bio->bi_private = ctx;

	}

	return ctx;

}



static inline loff_t ext4_readpage_limit(struct inode *inode)
@@ -371,24 +370,16 @@ int ext4_mpage_readpages(struct address_space *mapping, 
			bio = NULL;

		}

		if (bio == NULL) {

			struct bio_post_read_ctx *ctx;



			/*

			 * bio_alloc will _always_ be able to allocate a bio if

			 * __GFP_DIRECT_RECLAIM is set, see bio_alloc_bioset().

			 */

			bio = bio_alloc(GFP_KERNEL,

				min_t(int, nr_pages, BIO_MAX_PAGES));

			ctx = get_bio_post_read_ctx(inode, bio, page->index);

			if (IS_ERR(ctx)) {

				bio_put(bio);

				bio = NULL;

				goto set_error_page;

			}

			ext4_set_bio_post_read_ctx(bio, inode, page->index);

			bio_set_dev(bio, bdev);

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

			bio->bi_end_io = mpage_end_io;

			bio->bi_private = ctx;

			bio_set_op_attrs(bio, REQ_OP_READ,

						is_readahead ? REQ_RAHEAD : 0);

		}