md: do not count blocked devices as spares

[pandora-kernel.git] / fs / bio.c

diff --git a/fs/bio.c b/fs/bio.c
index 6e0b6f6..7856257 100644 (file)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -158,7 +158,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 
                bio_init(bio);
                if (likely(nr_iovecs)) {
-                       unsigned long idx = 0; /* shut up gcc */
+                       unsigned long uninitialized_var(idx);
 
                        bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
                        if (unlikely(!bvl)) {
@@ -937,6 +937,96 @@ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
        return ERR_PTR(-EINVAL);
 }
 
+static void bio_copy_kern_endio(struct bio *bio, int err)
+{
+       struct bio_vec *bvec;
+       const int read = bio_data_dir(bio) == READ;
+       char *p = bio->bi_private;
+       int i;
+
+       __bio_for_each_segment(bvec, bio, i, 0) {
+               char *addr = page_address(bvec->bv_page);
+
+               if (read && !err)
+                       memcpy(p, addr, bvec->bv_len);
+
+               __free_page(bvec->bv_page);
+               p += bvec->bv_len;
+       }
+
+       bio_put(bio);
+}
+
+/**
+ *     bio_copy_kern   -       copy kernel address into bio
+ *     @q: the struct request_queue for the bio
+ *     @data: pointer to buffer to copy
+ *     @len: length in bytes
+ *     @gfp_mask: allocation flags for bio and page allocation
+ *     @reading: data direction is READ
+ *
+ *     copy the kernel address into a bio suitable for io to a block
+ *     device. Returns an error pointer in case of error.
+ */
+struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
+                         gfp_t gfp_mask, int reading)
+{
+       unsigned long kaddr = (unsigned long)data;
+       unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       unsigned long start = kaddr >> PAGE_SHIFT;
+       const int nr_pages = end - start;
+       struct bio *bio;
+       struct bio_vec *bvec;
+       int i, ret;
+
+       bio = bio_alloc(gfp_mask, nr_pages);
+       if (!bio)
+               return ERR_PTR(-ENOMEM);
+
+       while (len) {
+               struct page *page;
+               unsigned int bytes = PAGE_SIZE;
+
+               if (bytes > len)
+                       bytes = len;
+
+               page = alloc_page(q->bounce_gfp | gfp_mask);
+               if (!page) {
+                       ret = -ENOMEM;
+                       goto cleanup;
+               }
+
+               if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) {
+                       ret = -EINVAL;
+                       goto cleanup;
+               }
+
+               len -= bytes;
+       }
+
+       if (!reading) {
+               void *p = data;
+
+               bio_for_each_segment(bvec, bio, i) {
+                       char *addr = page_address(bvec->bv_page);
+
+                       memcpy(addr, p, bvec->bv_len);
+                       p += bvec->bv_len;
+               }
+       }
+
+       bio->bi_private = data;
+       bio->bi_end_io = bio_copy_kern_endio;
+       return bio;
+cleanup:
+       bio_for_each_segment(bvec, bio, i)
+               __free_page(bvec->bv_page);
+
+       bio_put(bio);
+
+       return ERR_PTR(ret);
+}
+
 /*
  * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
  * for performing direct-IO in BIOs.
@@ -1273,6 +1363,7 @@ EXPORT_SYMBOL(bio_get_nr_vecs);
 EXPORT_SYMBOL(bio_map_user);
 EXPORT_SYMBOL(bio_unmap_user);
 EXPORT_SYMBOL(bio_map_kern);
+EXPORT_SYMBOL(bio_copy_kern);
 EXPORT_SYMBOL(bio_pair_release);
 EXPORT_SYMBOL(bio_split);
 EXPORT_SYMBOL(bio_split_pool);