Merge tag 'nfsd-4.11' of git://linux-nfs.org/~bfields/linux

[karo-tx-linux.git] / block / bio.c

diff --git a/block/bio.c b/block/bio.c
index 2b375020fc49bab0bfcabda4fc3d16118b5f1512..5eec5e08417f6ff1989e3e2a07b31c62901953d5 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -625,21 +625,20 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
 }
 EXPORT_SYMBOL(bio_clone_fast);
 
-/**
- *     bio_clone_bioset - clone a bio
- *     @bio_src: bio to clone
- *     @gfp_mask: allocation priority
- *     @bs: bio_set to allocate from
- *
- *     Clone bio. Caller will own the returned bio, but not the actual data it
- *     points to. Reference count of returned bio will be one.
- */
-struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
-                            struct bio_set *bs)
+static struct bio *__bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
+                                     struct bio_set *bs, int offset,
+                                     int size)
 {
        struct bvec_iter iter;
        struct bio_vec bv;
        struct bio *bio;
+       struct bvec_iter iter_src = bio_src->bi_iter;
+
+       /* for supporting partial clone */
+       if (offset || size != bio_src->bi_iter.bi_size) {
+               bio_advance_iter(bio_src, &iter_src, offset);
+               iter_src.bi_size = size;
+       }
 
        /*
         * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
@@ -663,7 +662,8 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
         *    __bio_clone_fast() anyways.
         */
 
-       bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
+       bio = bio_alloc_bioset(gfp_mask, __bio_segments(bio_src,
+                              &iter_src), bs);
        if (!bio)
                return NULL;
        bio->bi_bdev            = bio_src->bi_bdev;
@@ -680,7 +680,7 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
                bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
                break;
        default:
-               bio_for_each_segment(bv, bio_src, iter)
+               __bio_for_each_segment(bv, bio_src, iter, iter_src)
                        bio->bi_io_vec[bio->bi_vcnt++] = bv;
                break;
        }
@@ -699,8 +699,43 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
 
        return bio;
 }
+
+/**
+ *     bio_clone_bioset - clone a bio
+ *     @bio_src: bio to clone
+ *     @gfp_mask: allocation priority
+ *     @bs: bio_set to allocate from
+ *
+ *     Clone bio. Caller will own the returned bio, but not the actual data it
+ *     points to. Reference count of returned bio will be one.
+ */
+struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
+                            struct bio_set *bs)
+{
+       return __bio_clone_bioset(bio_src, gfp_mask, bs, 0,
+                                 bio_src->bi_iter.bi_size);
+}
 EXPORT_SYMBOL(bio_clone_bioset);
 
+/**
+ *     bio_clone_bioset_partial - clone a partial bio
+ *     @bio_src: bio to clone
+ *     @gfp_mask: allocation priority
+ *     @bs: bio_set to allocate from
+ *     @offset: cloned starting from the offset
+ *     @size: size for the cloned bio
+ *
+ *     Clone bio. Caller will own the returned bio, but not the actual data it
+ *     points to. Reference count of returned bio will be one.
+ */
+struct bio *bio_clone_bioset_partial(struct bio *bio_src, gfp_t gfp_mask,
+                                    struct bio_set *bs, int offset,
+                                    int size)
+{
+       return __bio_clone_bioset(bio_src, gfp_mask, bs, offset, size);
+}
+EXPORT_SYMBOL(bio_clone_bioset_partial);
+
 /**
  *     bio_add_pc_page -       attempt to add page to bio
  *     @q: the target queue
@@ -1227,9 +1262,6 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
        if (!bio)
                goto out_bmd;
 
-       if (iter->type & WRITE)
-               bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-
        ret = 0;
 
        if (map_data) {
@@ -1394,16 +1426,10 @@ struct bio *bio_map_user_iov(struct request_queue *q,
 
        kfree(pages);
 
-       /*
-        * set data direction, and check if mapped pages need bouncing
-        */
-       if (iter->type & WRITE)
-               bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-
        bio_set_flag(bio, BIO_USER_MAPPED);
 
        /*
-        * subtle -- if __bio_map_user() ended up bouncing a bio,
+        * subtle -- if bio_map_user_iov() ended up bouncing a bio,
         * it would normally disappear when its bi_end_io is run.
         * however, we need it for the unmap, so grab an extra
         * reference to it
@@ -1445,8 +1471,8 @@ static void __bio_unmap_user(struct bio *bio)
  *     bio_unmap_user  -       unmap a bio
  *     @bio:           the bio being unmapped
  *
- *     Unmap a bio previously mapped by bio_map_user(). Must be called with
- *     a process context.
+ *     Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
+ *     process context.
  *
  *     bio_unmap_user() may sleep.
  */
@@ -1590,7 +1616,6 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
                bio->bi_private = data;
        } else {
                bio->bi_end_io = bio_copy_kern_endio;
-               bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
        }
 
        return bio;