Commit 32506af5 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Remove redundant bio_get/set calls in compressed read/write paths 



bio_get/set is necessary only if the bio is going to be referenced
following submissions. In the code paths where such calls are made
we don't really need them since the bio is referenced only if
btrfs_map_bio returns an error. And this function can return an error
prior to submission only. So referencing the bio is safe. Furthermore
we do call bio_endio which will consume the last reference. So let's
remove the redundant calls.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 4271ecea

fs/btrfs/compression.c

+0 −12
Original line number Diff line number Diff line
@@ -362,8 +362,6 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, 
		page->mapping = NULL;

		if (submit || bio_add_page(bio, page, PAGE_SIZE, 0) <

		    PAGE_SIZE) {

			bio_get(bio);



			/*

			 * inc the count before we submit the bio so

			 * we know the end IO handler won't happen before
@@ -386,8 +384,6 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, 
				bio_endio(bio);

			}



			bio_put(bio);



			bio = btrfs_bio_alloc(bdev, first_byte);

			bio->bi_opf = REQ_OP_WRITE | write_flags;

			bio->bi_private = cb;
@@ -403,7 +399,6 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, 
		first_byte += PAGE_SIZE;

		cond_resched();

	}

	bio_get(bio);



	ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);

	BUG_ON(ret); /* -ENOMEM */
@@ -419,7 +414,6 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, 
		bio_endio(bio);

	}



	bio_put(bio);

	return 0;

}
@@ -652,8 +646,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
		page->mapping = NULL;

		if (submit || bio_add_page(comp_bio, page, PAGE_SIZE, 0) <

		    PAGE_SIZE) {

			bio_get(comp_bio);



			ret = btrfs_bio_wq_end_io(fs_info, comp_bio,

						  BTRFS_WQ_ENDIO_DATA);

			BUG_ON(ret); /* -ENOMEM */
@@ -680,8 +672,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
				bio_endio(comp_bio);

			}



			bio_put(comp_bio);



			comp_bio = btrfs_bio_alloc(bdev, cur_disk_byte);

			bio_set_op_attrs(comp_bio, REQ_OP_READ, 0);

			comp_bio->bi_private = cb;
@@ -691,7 +681,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
		}

		cur_disk_byte += PAGE_SIZE;

	}

	bio_get(comp_bio);



	ret = btrfs_bio_wq_end_io(fs_info, comp_bio, BTRFS_WQ_ENDIO_DATA);

	BUG_ON(ret); /* -ENOMEM */
@@ -707,7 +696,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
		bio_endio(comp_bio);

	}



	bio_put(comp_bio);

	return 0;



fail2:

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