proc: less LOCK operations during lookup

[safe/jmp/linux-2.6] / fs / bio.c

diff --git a/fs/bio.c b/fs/bio.c
index ac987fc..242e409 100644 (file)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -109,11 +109,14 @@ static inline struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned lon
 
 void bio_free(struct bio *bio, struct bio_set *bio_set)
 {
-       const int pool_idx = BIO_POOL_IDX(bio);
+       if (bio->bi_io_vec) {
+               const int pool_idx = BIO_POOL_IDX(bio);
 
-       BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS);
+               BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS);
+
+               mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]);
+       }
 
-       mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]);
        mempool_free(bio, bio_set->bio_pool);
 }
 
@@ -245,11 +248,13 @@ inline int bio_hw_segments(struct request_queue *q, struct bio *bio)
  */
 void __bio_clone(struct bio *bio, struct bio *bio_src)
 {
-       struct request_queue *q = bdev_get_queue(bio_src->bi_bdev);
-
        memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
                bio_src->bi_max_vecs * sizeof(struct bio_vec));
 
+       /*
+        * most users will be overriding ->bi_bdev with a new target,
+        * so we don't set nor calculate new physical/hw segment counts here
+        */
        bio->bi_sector = bio_src->bi_sector;
        bio->bi_bdev = bio_src->bi_bdev;
        bio->bi_flags |= 1 << BIO_CLONED;
@@ -257,8 +262,6 @@ void __bio_clone(struct bio *bio, struct bio *bio_src)
        bio->bi_vcnt = bio_src->bi_vcnt;
        bio->bi_size = bio_src->bi_size;
        bio->bi_idx = bio_src->bi_idx;
-       bio_phys_segments(q, bio);
-       bio_hw_segments(q, bio);
 }
 
 /**