1 files changed, 13 insertions, 12 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 76e6713abf94..e1f922184b45 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -78,7 +78,7 @@ static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
 
         i = 0;
         while (i < bio_slab_nr) {
-                struct bio_slab *bslab = &bio_slabs[i];
+                bslab = &bio_slabs[i];
 
                 if (!bslab->slab && entry == -1)
                         entry = i;
@@ -264,13 +264,12 @@ EXPORT_SYMBOL(bio_init);
  * bio_alloc_bioset - allocate a bio for I/O
  * @gfp_mask:   the GFP_ mask given to the slab allocator
  * @nr_iovecs:  number of iovecs to pre-allocate
- * @bs:         the bio_set to allocate from. If %NULL, just use kmalloc
+ * @bs:         the bio_set to allocate from.
  *
  * Description:
- *   bio_alloc_bioset will first try its own mempool to satisfy the allocation.
+ *   bio_alloc_bioset will try its own mempool to satisfy the allocation.
  *   If %__GFP_WAIT is set then we will block on the internal pool waiting
- *   for a &struct bio to become free. If a %NULL @bs is passed in, we will
- *   fall back to just using @kmalloc to allocate the required memory.
+ *   for a &struct bio to become free.
  *
  *   Note that the caller must set ->bi_destructor on successful return
  *   of a bio, to do the appropriate freeing of the bio once the reference
@@ -507,10 +506,8 @@ int bio_get_nr_vecs(struct block_device *bdev)
         int nr_pages;
 
         nr_pages = ((queue_max_sectors(q) << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        if (nr_pages > queue_max_phys_segments(q))
-                nr_pages = queue_max_phys_segments(q);
-        if (nr_pages > queue_max_hw_segments(q))
-                nr_pages = queue_max_hw_segments(q);
+        if (nr_pages > queue_max_segments(q))
+                nr_pages = queue_max_segments(q);
 
         return nr_pages;
 }
@@ -542,13 +539,18 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 
                 if (page == prev->bv_page &&
                     offset == prev->bv_offset + prev->bv_len) {
+                        unsigned int prev_bv_len = prev->bv_len;
                         prev->bv_len += len;
 
                         if (q->merge_bvec_fn) {
                                 struct bvec_merge_data bvm = {
+                                        /* prev_bvec is already charged in
+                                           bi_size, discharge it in order to
+                                           simulate merging updated prev_bvec
+                                           as new bvec. */
                                         .bi_bdev = bio->bi_bdev,
                                         .bi_sector = bio->bi_sector,
-                                        .bi_size = bio->bi_size,
+                                        .bi_size = bio->bi_size - prev_bv_len,
                                         .bi_rw = bio->bi_rw,
                                 };
 
@@ -570,8 +572,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
          * make this too complex.
          */
 
-        while (bio->bi_phys_segments >= queue_max_phys_segments(q)
-               || bio->bi_phys_segments >= queue_max_hw_segments(q)) {
+        while (bio->bi_phys_segments >= queue_max_segments(q)) {
 
                 if (retried_segments)
                         return 0;