orangefs: pass slot index back to readpage.

When userspace deposits more than a page of data into the shared buffer,
we'll need to know which slot it is in when we get back to readpage
so that we can try to use the extra data to fill some extra pages.
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Martin Brandenburg <martin@omnibond.com>

fs/orangefs/file.c

@@ -47,7 +47,7 @@ static int flush_racache(struct inode *inode)
  */
 ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,
     loff_t *offset, struct iov_iter *iter, size_t total_size,
-    loff_t readahead_size, struct orangefs_write_range *wr)
+    loff_t readahead_size, struct orangefs_write_range *wr, int *index_return)
 {
 	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
 	struct orangefs_khandle *handle = &orangefs_inode->refn.khandle;

fs/orangefs/inode.c

@@ -55,7 +55,7 @@ static int orangefs_writepage_locked(struct page *page,
 	iov_iter_bvec(&iter, WRITE, &bv, 1, wlen);
 
 	ret = wait_for_direct_io(ORANGEFS_IO_WRITE, inode, &off, &iter, wlen,
-	    len, wr);
+	    len, wr, NULL);
 	if (ret < 0) {
 		SetPageError(page);
 		mapping_set_error(page->mapping, ret);
@@ -126,7 +126,7 @@ static int orangefs_writepages_work(struct orangefs_writepages *ow,
 	wr.uid = ow->uid;
 	wr.gid = ow->gid;
 	ret = wait_for_direct_io(ORANGEFS_IO_WRITE, inode, &off, &iter, ow->len,
-	    0, &wr);
+	    0, &wr, NULL);
 	if (ret < 0) {
 		for (i = 0; i < ow->npages; i++) {
 			SetPageError(ow->pages[i]);
@@ -265,7 +265,7 @@ static int orangefs_readpage(struct file *file, struct page *page)
 		orangefs_launder_page(page);
 
 	ret = wait_for_direct_io(ORANGEFS_IO_READ, inode, &off, &iter,
-	    PAGE_SIZE, inode->i_size, NULL);
+	    PAGE_SIZE, inode->i_size, NULL, NULL);
 	/* this will only zero remaining unread portions of the page data */
 	iov_iter_zero(~0U, &iter);
 	/* takes care of potential aliasing */
@@ -552,7 +552,7 @@ static ssize_t orangefs_direct_IO(struct kiocb *iocb,
 			     (int)*offset);
 
 		ret = wait_for_direct_io(type, inode, offset, iter,
-				each_count, 0, NULL);
+				each_count, 0, NULL, NULL);
 		gossip_debug(GOSSIP_FILE_DEBUG,
 			     "%s(%pU): return from wait_for_io:%d\n",
 			     __func__,

fs/orangefs/orangefs-kernel.h

@@ -398,7 +398,7 @@ bool __is_daemon_in_service(void);
  */
 int orangefs_revalidate_mapping(struct inode *);
 ssize_t wait_for_direct_io(enum ORANGEFS_io_type, struct inode *, loff_t *,
-    struct iov_iter *, size_t, loff_t, struct orangefs_write_range *);
+    struct iov_iter *, size_t, loff_t, struct orangefs_write_range *, int *);
 ssize_t do_readv_writev(enum ORANGEFS_io_type, struct file *, loff_t *,
     struct iov_iter *);