Commit b7321bcc authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Greg Kroah-Hartman

fuse: fix fuse_write_end() if zero bytes were copied

commit 59c3b76c upstream.

If pos is at the beginning of a page and copied is zero then page is not
zeroed but is marked uptodate.

Fix by skipping everything except unlock/put of page if zero bytes were
copied.
Reported-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Fixes: 6b12c1b3 ("fuse: Implement write_begin/write_end callbacks")
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d4a774fd
......@@ -1997,6 +1997,10 @@ static int fuse_write_end(struct file *file, struct address_space *mapping,
{
struct inode *inode = page->mapping->host;
/* Haven't copied anything? Skip zeroing, size extending, dirtying. */
if (!copied)
goto unlock;
if (!PageUptodate(page)) {
/* Zero any unwritten bytes at the end of the page */
size_t endoff = (pos + copied) & ~PAGE_CACHE_MASK;
......@@ -2007,6 +2011,8 @@ static int fuse_write_end(struct file *file, struct address_space *mapping,
fuse_write_update_size(inode, pos + copied);
set_page_dirty(page);
unlock:
unlock_page(page);
page_cache_release(page);
......
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