orangefs: migrate to generic_file_read_iter

Remove orangefs_inode_read.  It was used by readpage.  Calling
wait_for_direct_io directly serves the purpose just as well.  There is
now no check of the bufmap size in the readpage path.  There are already
other places the bufmap size is assumed to be greater than PAGE_SIZE.

Important to call truncate_inode_pages now in the write path so a
subsequent read sees the new data.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

1 files changed, 23 insertions, 40 deletions

diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
index fd23a8ca641c..31ee3cb67fe0 100644
--- a/fs/orangefs/inode.c
+++ b/fs/orangefs/inode.c
@@ -17,37 +17,25 @@
 
 static int orangefs_readpage(struct file *file, struct page *page)
 {
-	int ret;
-	int max_block;
-	ssize_t bytes_read = 0;
 	struct inode *inode = page->mapping->host;
-	const __u32 blocksize = PAGE_SIZE;
-	const __u32 blockbits = PAGE_SHIFT;
-	struct iov_iter to;
-	struct bio_vec bv = {.bv_page = page, .bv_len = PAGE_SIZE};
-
-	iov_iter_bvec(&to, READ, &bv, 1, PAGE_SIZE);
-
-	gossip_debug(GOSSIP_INODE_DEBUG,
-		    "orangefs_readpage called with page %p\n",
-		     page);
-
-	max_block = ((inode->i_size / blocksize) + 1);
-
-	if (page->index < max_block) {
-		loff_t blockptr_offset = (((loff_t) page->index) << blockbits);
-
-		bytes_read = orangefs_inode_read(inode,
-						 &to,
-						 &blockptr_offset,
-						 inode->i_size);
-	}
+	struct iov_iter iter;
+	struct bio_vec bv;
+	ssize_t ret;
+	loff_t off;
+
+	off = page_offset(page);
+	bv.bv_page = page;
+	bv.bv_len = PAGE_SIZE;
+	bv.bv_offset = 0;
+	iov_iter_bvec(&iter, READ, &bv, 1, PAGE_SIZE);
+
+	ret = wait_for_direct_io(ORANGEFS_IO_READ, inode, &off, &iter,
+	    PAGE_SIZE, inode->i_size);
 	/* this will only zero remaining unread portions of the page data */
-	iov_iter_zero(~0U, &to);
+	iov_iter_zero(~0U, &iter);
 	/* takes care of potential aliasing */
 	flush_dcache_page(page);
-	if (bytes_read < 0) {
-		ret = bytes_read;
+	if (ret < 0) {
 		SetPageError(page);
 	} else {
 		SetPageUptodate(page);
@@ -84,22 +72,17 @@ static int orangefs_releasepage(struct page *page, gfp_t foo)
 	return 0;
 }
 
-/*
- * Having a direct_IO entry point in the address_space_operations
- * struct causes the kernel to allows us to use O_DIRECT on
- * open. Nothing will ever call this thing, but in the future we
- * will need to be able to use O_DIRECT on open in order to support
- * AIO. Modeled after NFS, they do this too.
- */
-
 static ssize_t orangefs_direct_IO(struct kiocb *iocb,
 				  struct iov_iter *iter)
 {
-	gossip_debug(GOSSIP_INODE_DEBUG,
-		     "orangefs_direct_IO: %pD\n",
-		     iocb->ki_filp);
-
-	return -EINVAL;
+	struct file *file = iocb->ki_filp;
+	loff_t pos = *(&iocb->ki_pos);
+	/*
+	 * This cannot happen until write_iter becomes
+	 * generic_file_write_iter.
+	 */
+	BUG_ON(iov_iter_rw(iter) != READ);
+	return do_readv_writev(ORANGEFS_IO_READ, file, &pos, iter);
 }
 
 /** ORANGEFS2 implementation of address space operations */