gpio: reduce descriptor validation code size
[sfrench/cifs-2.6.git] / block / bio.c
index b94a802f8ba341894d6c4eafb0c04f87eacbe1c6..228229f3bb76d2f9770b2191cee67328b6f9e983 100644 (file)
@@ -597,6 +597,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
         * so we don't set nor calculate new physical/hw segment counts here
         */
        bio->bi_disk = bio_src->bi_disk;
+       bio->bi_partno = bio_src->bi_partno;
        bio_set_flag(bio, BIO_CLONED);
        bio->bi_opf = bio_src->bi_opf;
        bio->bi_write_hint = bio_src->bi_write_hint;
@@ -1061,14 +1062,21 @@ struct bio_map_data {
        struct iovec iov[];
 };
 
-static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count,
+static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
                                               gfp_t gfp_mask)
 {
-       if (iov_count > UIO_MAXIOV)
+       struct bio_map_data *bmd;
+       if (data->nr_segs > UIO_MAXIOV)
                return NULL;
 
-       return kmalloc(sizeof(struct bio_map_data) +
-                      sizeof(struct iovec) * iov_count, gfp_mask);
+       bmd = kmalloc(sizeof(struct bio_map_data) +
+                      sizeof(struct iovec) * data->nr_segs, gfp_mask);
+       if (!bmd)
+               return NULL;
+       memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
+       bmd->iter = *data;
+       bmd->iter.iov = bmd->iov;
+       return bmd;
 }
 
 /**
@@ -1079,7 +1087,7 @@ static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count,
  * Copy all pages from iov_iter to bio.
  * Returns 0 on success, or error on failure.
  */
-static int bio_copy_from_iter(struct bio *bio, struct iov_iter iter)
+static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
 {
        int i;
        struct bio_vec *bvec;
@@ -1090,9 +1098,9 @@ static int bio_copy_from_iter(struct bio *bio, struct iov_iter iter)
                ret = copy_page_from_iter(bvec->bv_page,
                                          bvec->bv_offset,
                                          bvec->bv_len,
-                                         &iter);
+                                         iter);
 
-               if (!iov_iter_count(&iter))
+               if (!iov_iter_count(iter))
                        break;
 
                if (ret < bvec->bv_len)
@@ -1186,40 +1194,18 @@ int bio_uncopy_user(struct bio *bio)
  */
 struct bio *bio_copy_user_iov(struct request_queue *q,
                              struct rq_map_data *map_data,
-                             const struct iov_iter *iter,
+                             struct iov_iter *iter,
                              gfp_t gfp_mask)
 {
        struct bio_map_data *bmd;
        struct page *page;
        struct bio *bio;
-       int i, ret;
-       int nr_pages = 0;
+       int i = 0, ret;
+       int nr_pages;
        unsigned int len = iter->count;
        unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
 
-       for (i = 0; i < iter->nr_segs; i++) {
-               unsigned long uaddr;
-               unsigned long end;
-               unsigned long start;
-
-               uaddr = (unsigned long) iter->iov[i].iov_base;
-               end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)
-                       >> PAGE_SHIFT;
-               start = uaddr >> PAGE_SHIFT;
-
-               /*
-                * Overflow, abort
-                */
-               if (end < start)
-                       return ERR_PTR(-EINVAL);
-
-               nr_pages += end - start;
-       }
-
-       if (offset)
-               nr_pages++;
-
-       bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask);
+       bmd = bio_alloc_map_data(iter, gfp_mask);
        if (!bmd)
                return ERR_PTR(-ENOMEM);
 
@@ -1229,9 +1215,10 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
         * shortlived one.
         */
        bmd->is_our_pages = map_data ? 0 : 1;
-       memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs);
-       bmd->iter = *iter;
-       bmd->iter.iov = bmd->iov;
+
+       nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+       if (nr_pages > BIO_MAX_PAGES)
+               nr_pages = BIO_MAX_PAGES;
 
        ret = -ENOMEM;
        bio = bio_kmalloc(gfp_mask, nr_pages);
@@ -1280,17 +1267,24 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
        if (ret)
                goto cleanup;
 
+       if (map_data)
+               map_data->offset += bio->bi_iter.bi_size;
+
        /*
         * success
         */
        if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||
            (map_data && map_data->from_user)) {
-               ret = bio_copy_from_iter(bio, *iter);
+               ret = bio_copy_from_iter(bio, iter);
                if (ret)
                        goto cleanup;
+       } else {
+               iov_iter_advance(iter, bio->bi_iter.bi_size);
        }
 
        bio->bi_private = bmd;
+       if (map_data && map_data->null_mapped)
+               bio_set_flag(bio, BIO_NULL_MAPPED);
        return bio;
 cleanup:
        if (!map_data)
@@ -1311,111 +1305,74 @@ out_bmd:
  *     device. Returns an error pointer in case of error.
  */
 struct bio *bio_map_user_iov(struct request_queue *q,
-                            const struct iov_iter *iter,
+                            struct iov_iter *iter,
                             gfp_t gfp_mask)
 {
        int j;
-       int nr_pages = 0;
-       struct page **pages;
        struct bio *bio;
-       int cur_page = 0;
-       int ret, offset;
-       struct iov_iter i;
-       struct iovec iov;
+       int ret;
        struct bio_vec *bvec;
 
-       iov_for_each(iov, i, *iter) {
-               unsigned long uaddr = (unsigned long) iov.iov_base;
-               unsigned long len = iov.iov_len;
-               unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-               unsigned long start = uaddr >> PAGE_SHIFT;
-
-               /*
-                * Overflow, abort
-                */
-               if (end < start)
-                       return ERR_PTR(-EINVAL);
-
-               nr_pages += end - start;
-               /*
-                * buffer must be aligned to at least logical block size for now
-                */
-               if (uaddr & queue_dma_alignment(q))
-                       return ERR_PTR(-EINVAL);
-       }
-
-       if (!nr_pages)
+       if (!iov_iter_count(iter))
                return ERR_PTR(-EINVAL);
 
-       bio = bio_kmalloc(gfp_mask, nr_pages);
+       bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));
        if (!bio)
                return ERR_PTR(-ENOMEM);
 
-       ret = -ENOMEM;
-       pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
-       if (!pages)
-               goto out;
+       while (iov_iter_count(iter)) {
+               struct page **pages;
+               ssize_t bytes;
+               size_t offs, added = 0;
+               int npages;
 
-       iov_for_each(iov, i, *iter) {
-               unsigned long uaddr = (unsigned long) iov.iov_base;
-               unsigned long len = iov.iov_len;
-               unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-               unsigned long start = uaddr >> PAGE_SHIFT;
-               const int local_nr_pages = end - start;
-               const int page_limit = cur_page + local_nr_pages;
-
-               ret = get_user_pages_fast(uaddr, local_nr_pages,
-                               (iter->type & WRITE) != WRITE,
-                               &pages[cur_page]);
-               if (unlikely(ret < local_nr_pages)) {
-                       for (j = cur_page; j < page_limit; j++) {
-                               if (!pages[j])
-                                       break;
-                               put_page(pages[j]);
-                       }
-                       ret = -EFAULT;
+               bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);
+               if (unlikely(bytes <= 0)) {
+                       ret = bytes ? bytes : -EFAULT;
                        goto out_unmap;
                }
 
-               offset = offset_in_page(uaddr);
-               for (j = cur_page; j < page_limit; j++) {
-                       unsigned int bytes = PAGE_SIZE - offset;
-                       unsigned short prev_bi_vcnt = bio->bi_vcnt;
+               npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
 
-                       if (len <= 0)
-                               break;
-                       
-                       if (bytes > len)
-                               bytes = len;
-
-                       /*
-                        * sorry...
-                        */
-                       if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
-                                           bytes)
-                               break;
+               if (unlikely(offs & queue_dma_alignment(q))) {
+                       ret = -EINVAL;
+                       j = 0;
+               } else {
+                       for (j = 0; j < npages; j++) {
+                               struct page *page = pages[j];
+                               unsigned int n = PAGE_SIZE - offs;
+                               unsigned short prev_bi_vcnt = bio->bi_vcnt;
 
-                       /*
-                        * check if vector was merged with previous
-                        * drop page reference if needed
-                        */
-                       if (bio->bi_vcnt == prev_bi_vcnt)
-                               put_page(pages[j]);
+                               if (n > bytes)
+                                       n = bytes;
 
-                       len -= bytes;
-                       offset = 0;
-               }
+                               if (!bio_add_pc_page(q, bio, page, n, offs))
+                                       break;
 
-               cur_page = j;
+                               /*
+                                * check if vector was merged with previous
+                                * drop page reference if needed
+                                */
+                               if (bio->bi_vcnt == prev_bi_vcnt)
+                                       put_page(page);
+
+                               added += n;
+                               bytes -= n;
+                               offs = 0;
+                       }
+                       iov_iter_advance(iter, added);
+               }
                /*
                 * release the pages we didn't map into the bio, if any
                 */
-               while (j < page_limit)
+               while (j < npages)
                        put_page(pages[j++]);
+               kvfree(pages);
+               /* couldn't stuff something into bio? */
+               if (bytes)
+                       break;
        }
 
-       kfree(pages);
-
        bio_set_flag(bio, BIO_USER_MAPPED);
 
        /*
@@ -1431,8 +1388,6 @@ struct bio *bio_map_user_iov(struct request_queue *q,
        bio_for_each_segment_all(bvec, bio, j) {
                put_page(bvec->bv_page);
        }
- out:
-       kfree(pages);
        bio_put(bio);
        return ERR_PTR(ret);
 }