[PATCH 2/2] iomap: Add helper for un-inlining an inline inode

[Andreas Gruenbacher <agruenba@redhat.com>]

From: Bob Peterson <rpeterso@redhat.com>

Add function iomap_uninline_inode for converting an inline inode into a
non-inline inode.  This takes care of attaching a new iomap_page object
to page->private if the block size is smaller than the page size.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/iomap/buffered-io.c | 24 ++++++++++++++++++++++++
 include/linux/iomap.h  |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 03537ecb2a94..44acb59191b2 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -226,6 +226,30 @@ iomap_read_inline_data(struct inode *inode, struct page *page,
 	SetPageUptodate(page);
 }
 
+int iomap_uninline_inode(struct inode *inode,
+		int (*uninline)(struct inode *, struct page *))
+{
+	struct page *page = NULL;
+	int ret;
+
+	if (i_size_read(inode)) {
+		page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS);
+		if (!page)
+			return -ENOMEM;
+	}
+	ret = uninline(inode, page);
+	if (page) {
+		if (PageUptodate(page)) {
+			iomap_page_create(inode, page);
+			iomap_set_range_uptodate(page, 0, PAGE_SIZE);
+		}
+		unlock_page(page);
+		put_page(page);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iomap_uninline_inode);
+
 static inline bool iomap_block_needs_zeroing(struct inode *inode,
 		struct iomap *iomap, loff_t pos)
 {
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index c87d0cb0de6d..90c924eec09b 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -157,6 +157,8 @@ loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,
 
 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
 		const struct iomap_ops *ops);
+int iomap_uninline_inode(struct inode *inode,
+                int (*uninline)(struct inode *, struct page *));
 int iomap_readpage(struct page *page, const struct iomap_ops *ops);
 void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops);
 int iomap_set_page_dirty(struct page *page);
-- 
2.26.3