fix race in d_splice_alias()

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

diff --git a/fs/bio.c b/fs/bio.c
index 2bd671a..88094af 100644 (file)
--- 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;
@@ -542,13 +542,18 @@ 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,
                                };
 
@@ -1393,6 +1398,18 @@ 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