From: Hu Weiwen sehuww@mail.scut.edu.cn
commit 7cb9994754f8a36ae9e5ec4597c5c4c2d6c03832 upstream.
Clear O_TRUNC from the flags sent in the MDS create request.
`atomic_open' is called before permission check. We should not do any modification to the file here. The caller will do the truncation afterward.
Fixes: 124e68e74099 ("ceph: file operations") Signed-off-by: Hu Weiwen sehuww@mail.scut.edu.cn Reviewed-by: Xiubo Li xiubli@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com [Xiubo: fixed a trivial conflict for 4.9 backport] Signed-off-by: Xiubo Li xiubli@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ceph/file.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -354,6 +354,11 @@ int ceph_atomic_open(struct inode *dir, err = ceph_init_dentry(dentry); if (err < 0) return err; + /* + * Do not truncate the file, since atomic_open is called before the + * permission check. The caller will do the truncation afterward. + */ + flags &= ~O_TRUNC;
if (flags & O_CREAT) { err = ceph_pre_init_acls(dir, &mode, &acls); @@ -384,9 +389,7 @@ int ceph_atomic_open(struct inode *dir, req->r_args.open.mask = cpu_to_le32(mask);
req->r_locked_dir = dir; /* caller holds dir->i_mutex */ - err = ceph_mdsc_do_request(mdsc, - (flags & (O_CREAT|O_TRUNC)) ? dir : NULL, - req); + err = ceph_mdsc_do_request(mdsc, (flags & O_CREAT) ? dir : NULL, req); err = ceph_handle_snapdir(req, dentry, err); if (err) goto out_req;