Merge branch 'perf' into devel

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

diff --git a/fs/bio.c b/fs/bio.c
index 402cb84..76e6713 100644 (file)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -272,7 +272,7 @@ EXPORT_SYMBOL(bio_init);
  *   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.
  *
- *   Note that the caller must set ->bi_destructor on succesful return
+ *   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
  *   count drops to zero.
  **/
@@ -325,8 +325,16 @@ static void bio_fs_destructor(struct bio *bio)
  *     @gfp_mask: allocation mask to use
  *     @nr_iovecs: number of iovecs
  *
- *     Allocate a new bio with @nr_iovecs bvecs.  If @gfp_mask
- *     contains __GFP_WAIT, the allocation is guaranteed to succeed.
+ *     bio_alloc will allocate a bio and associated bio_vec array that can hold
+ *     at least @nr_iovecs entries. Allocations will be done from the
+ *     fs_bio_set. Also see @bio_alloc_bioset and @bio_kmalloc.
+ *
+ *     If %__GFP_WAIT is set, then bio_alloc will always be able to allocate
+ *     a bio. This is due to the mempool guarantees. To make this work, callers
+ *     must never allocate more than 1 bio at a time from this pool. Callers
+ *     that need to allocate more than 1 bio must always submit the previously
+ *     allocated bio for IO before attempting to allocate a new one. Failure to
+ *     do so can cause livelocks under memory pressure.
  *
  *     RETURNS:
  *     Pointer to new bio on success, NULL on failure.
@@ -350,21 +358,13 @@ static void bio_kmalloc_destructor(struct bio *bio)
 }
 
 /**
- * bio_alloc - allocate a bio for I/O
+ * bio_kmalloc - allocate a bio for I/O using kmalloc()
  * @gfp_mask:   the GFP_ mask given to the slab allocator
  * @nr_iovecs: number of iovecs to pre-allocate
  *
  * Description:
- *   bio_alloc will allocate a bio and associated bio_vec array that can hold
- *   at least @nr_iovecs entries. Allocations will be done from the
- *   fs_bio_set. Also see @bio_alloc_bioset.
- *
- *   If %__GFP_WAIT is set, then bio_alloc will always be able to allocate
- *   a bio. This is due to the mempool guarantees. To make this work, callers
- *   must never allocate more than 1 bio at a time from this pool. Callers
- *   that need to allocate more than 1 bio must always submit the previously
- *   allocated bio for IO before attempting to allocate a new one. Failure to
- *   do so can cause livelocks under memory pressure.
+ *   Allocate a new bio with @nr_iovecs bvecs.  If @gfp_mask contains
+ *   %__GFP_WAIT, the allocation is guaranteed to succeed.
  *
  **/
 struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
@@ -407,7 +407,7 @@ EXPORT_SYMBOL(zero_fill_bio);
  *
  * Description:
  *   Put a reference to a &struct bio, either one you have gotten with
- *   bio_alloc or bio_get. The last put of a bio will free it.
+ *   bio_alloc, bio_get or bio_clone. The last put of a bio will free it.
  **/
 void bio_put(struct bio *bio)
 {
@@ -1393,6 +1393,18 @@ void bio_check_pages_dirty(struct bio *bio)
        }
 }
 
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+void bio_flush_dcache_pages(struct bio *bi)
+{
+       int i;
+       struct bio_vec *bvec;
+
+       bio_for_each_segment(bvec, bi, i)
+               flush_dcache_page(bvec->bv_page);
+}
+EXPORT_SYMBOL(bio_flush_dcache_pages);
+#endif
+
 /**
  * bio_endio - end I/O on a bio
  * @bio:       bio