diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-08-18 09:10:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-26 09:56:54 +0100 |
| commit | ca720a2b11b4c90d1798b406d3c191cd5395b5e3 (patch) | |
| tree | ac97585291ba9748716671a967ad43c7bebe1228 /fs | |
| parent | de58c50e84e27ede34b509ad900414e43da5721a (diff) | |
fuse: fix fuse_write_end() if zero bytes were copied
commit 59c3b76cc61d1d676f965c192cc7969aa5cb2744 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: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 6b12c1b37e55 ("fuse: Implement write_begin/write_end callbacks")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fuse/file.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 3988b43c2f5a..a621dd98a865 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1985,6 +1985,10 @@ 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_MASK; @@ -1995,6 +1999,8 @@ 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); put_page(page); |