Commit 59c3b76c authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: fix fuse_write_end() if zero bytes were copied



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")
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 0ce267ff
...@@ -1985,6 +1985,10 @@ static int fuse_write_end(struct file *file, struct address_space *mapping, ...@@ -1985,6 +1985,10 @@ static int fuse_write_end(struct file *file, struct address_space *mapping,
{ {
struct inode *inode = page->mapping->host; struct inode *inode = page->mapping->host;
/* Haven't copied anything? Skip zeroing, size extending, dirtying. */
if (!copied)
goto unlock;
if (!PageUptodate(page)) { if (!PageUptodate(page)) {
/* Zero any unwritten bytes at the end of the page */ /* Zero any unwritten bytes at the end of the page */
size_t endoff = (pos + copied) & ~PAGE_MASK; size_t endoff = (pos + copied) & ~PAGE_MASK;
...@@ -1995,6 +1999,8 @@ static int fuse_write_end(struct file *file, struct address_space *mapping, ...@@ -1995,6 +1999,8 @@ static int fuse_write_end(struct file *file, struct address_space *mapping,
fuse_write_update_size(inode, pos + copied); fuse_write_update_size(inode, pos + copied);
set_page_dirty(page); set_page_dirty(page);
unlock:
unlock_page(page); unlock_page(page);
put_page(page); put_page(page);
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment