From: Paulo Alcantara pc@manguebit.com
commit d5a863a153e90996ab2aef6b9e08d509f4d5662b upstream.
@server->origin_fullpath already contains the tree name + optional prefix, so avoid calling __build_path_from_dentry_optional_prefix() as it might end up duplicating prefix path from @cifs_sb->prepath into final full path.
Instead, generate DFS full path by simply merging @server->origin_fullpath with dentry's path.
This fixes the following case
mount.cifs //root/dfs/dir /mnt/ -o ... ls /mnt/link
where cifs_dfs_do_automount() will call smb3_parse_devname() with @devname set to "//root/dfs/dir/link" instead of "//root/dfs/dir/dir/link".
Fixes: 7ad54b98fc1f ("cifs: use origin fullpath for automounts") Cc: stable@vger.kernel.org # 6.2+ Signed-off-by: Paulo Alcantara (SUSE) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/cifs/cifs_dfs_ref.c | 2 -- fs/cifs/dfs.h | 22 ++++++++++++++++++---- 2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index cb40074feb3e..0329a907bdfe 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -171,8 +171,6 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path) mnt = ERR_CAST(full_path); goto out; } - - convert_delimiter(full_path, '/'); cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
tmp = *cur_ctx; diff --git a/fs/cifs/dfs.h b/fs/cifs/dfs.h index 13f26e01f7b9..0b8cbf721fff 100644 --- a/fs/cifs/dfs.h +++ b/fs/cifs/dfs.h @@ -34,19 +34,33 @@ static inline int dfs_get_referral(struct cifs_mount_ctx *mnt_ctx, const char *p cifs_remap(cifs_sb), path, ref, tl); }
+/* Return DFS full path out of a dentry set for automount */ static inline char *dfs_get_automount_devname(struct dentry *dentry, void *page) { struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb); struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); struct TCP_Server_Info *server = tcon->ses->server; + size_t len; + char *s;
if (unlikely(!server->origin_fullpath)) return ERR_PTR(-EREMOTE);
- return __build_path_from_dentry_optional_prefix(dentry, page, - server->origin_fullpath, - strlen(server->origin_fullpath), - true); + s = dentry_path_raw(dentry, page, PATH_MAX); + if (IS_ERR(s)) + return s; + /* for root, we want "" */ + if (!s[1]) + s++; + + len = strlen(server->origin_fullpath); + if (s < (char *)page + len) + return ERR_PTR(-ENAMETOOLONG); + + s -= len; + memcpy(s, server->origin_fullpath, len); + convert_delimiter(s, '/'); + return s; }
static inline void dfs_put_root_smb_sessions(struct list_head *head)