+static ssize_t direct_IO_iovec(const struct iovec *iov, unsigned long nr_segs,
+ struct dio *dio, struct dio_submit *sdio,
+ unsigned blkbits, struct buffer_head *map_bh)
+{
+ size_t bytes;
+ ssize_t retval = 0;
+ int seg;
+ unsigned long user_addr;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ user_addr = (unsigned long)iov[seg].iov_base;
+ sdio->pages_in_io +=
+ ((user_addr + iov[seg].iov_len + PAGE_SIZE-1) /
+ PAGE_SIZE - user_addr / PAGE_SIZE);
+ }
+
+ dio->should_dirty = 1;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ user_addr = (unsigned long)iov[seg].iov_base;
+ sdio->size += bytes = iov[seg].iov_len;
+
+ /* Index into the first page of the first block */
+ sdio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
+ sdio->final_block_in_request = sdio->block_in_file +
+ (bytes >> blkbits);
+ /* Page fetching state */
+ sdio->head = 0;
+ sdio->tail = 0;
+ sdio->curr_page = 0;
+
+ sdio->total_pages = 0;
+ if (user_addr & (PAGE_SIZE-1)) {
+ sdio->total_pages++;
+ bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
+ }
+ sdio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
+ sdio->curr_user_address = user_addr;
+
+ retval = do_direct_IO(dio, sdio, map_bh);
+
+ dio->result += iov[seg].iov_len -
+ ((sdio->final_block_in_request - sdio->block_in_file) <<
+ blkbits);
+
+ if (retval) {
+ dio_cleanup(dio, sdio);
+ break;
+ }
+ } /* end iovec loop */
+
+ return retval;
+}
+
+static ssize_t direct_IO_bvec(struct bio_vec *bvec, unsigned long nr_segs,
+ struct dio *dio, struct dio_submit *sdio,
+ unsigned blkbits, struct buffer_head *map_bh)
+{
+ ssize_t retval = 0;
+ int seg;
+
+ sdio->pages_in_io += nr_segs;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ sdio->size += bvec[seg].bv_len;
+
+ /* Index into the first page of the first block */
+ sdio->first_block_in_page = bvec[seg].bv_offset >> blkbits;
+ sdio->final_block_in_request = sdio->block_in_file +
+ (bvec[seg].bv_len >> blkbits);
+ /* Page fetching state */
+ sdio->curr_page = 0;
+ page_cache_get(bvec[seg].bv_page);
+ dio->pages[0] = bvec[seg].bv_page;
+ sdio->head = 0;
+ sdio->tail = 1;
+
+ sdio->total_pages = 1;
+ sdio->curr_user_address = 0;
+
+ retval = do_direct_IO(dio, sdio, map_bh);
+
+ dio->result += bvec[seg].bv_len -
+ ((sdio->final_block_in_request - sdio->block_in_file) <<
+ blkbits);
+
+ if (retval) {
+ dio_cleanup(dio, sdio);
+ break;
+ }
+ }
+
+ return retval;
+}
+