From f9597a30b1702323dbd4df31ced3f77eed28728d Mon Sep 17 00:00:00 2001 From: Hu Weiwen Date: Fri, 1 Jul 2022 10:52:27 +0800 Subject: [PATCH] ceph: don't truncate file in atomic_open 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 Reviewed-by: Xiubo Li Signed-off-by: Ilya Dryomov [Xiubo: fixed a trivial conflict for 5.10 backport] Signed-off-by: Xiubo Li Signed-off-by: Greg Kroah-Hartman --- fs/ceph/file.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 4ce2752c8b71..95d7906fb9ea 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -446,6 +446,12 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry, if (dentry->d_name.len > NAME_MAX) return -ENAMETOOLONG; + /* + * 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) { if (ceph_quota_is_max_files_exceeded(dir)) return -EDQUOT; @@ -478,9 +484,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry, req->r_parent = dir; set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); - 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;