vfs_glusterfs: Use glfs_openat() for SMB_VFS_OPENAT

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15157

Signed-off-by: Anoop C S <anoopcs@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/modules/vfs_glusterfs.c b/source3/modules/vfs_glusterfs.c
index 92fc0a80e9f9b394880c9916651a52c7677ab484..3503dfc251f4427f0afbecf63ef73410f830cf97 100644 (file)
--- a/source3/modules/vfs_glusterfs.c
+++ b/source3/modules/vfs_glusterfs.c
@@ -765,9 +765,12 @@ static int vfs_gluster_openat(struct vfs_handle_struct *handle,
                              files_struct *fsp,
                              const struct vfs_open_how *how)
 {
-       struct smb_filename *name = NULL;
+       int flags = how->flags;
+       struct smb_filename *full_fname = NULL;
+       bool have_opath = false;
        bool became_root = false;
        glfs_fd_t *glfd;
+       glfs_fd_t *pglfd = NULL;
        glfs_fd_t **p_tmp;
 
        START_PROFILE(syscall_openat);
@@ -778,58 +781,103 @@ static int vfs_gluster_openat(struct vfs_handle_struct *handle,
                return -1;
        }
 
-       /*
-        * Looks like glfs API doesn't have openat().
-        */
-       if (fsp_get_pathref_fd(dirfsp) != AT_FDCWD) {
-               name = full_path_from_dirfsp_atname(talloc_tos(),
-                                                   dirfsp,
-                                                   smb_fname);
-               if (name == NULL) {
-                       END_PROFILE(syscall_openat);
-                       return -1;
-               }
-               smb_fname = name;
-       }
-
        p_tmp = VFS_ADD_FSP_EXTENSION(handle, fsp, glfs_fd_t *, NULL);
        if (p_tmp == NULL) {
-               TALLOC_FREE(name);
                END_PROFILE(syscall_openat);
                errno = ENOMEM;
                return -1;
        }
 
+#ifdef O_PATH
+       have_opath = true;
        if (fsp->fsp_flags.is_pathref) {
-               /*
-                * ceph doesn't support O_PATH so we have to fallback to
-                * become_root().
-                */
+               flags |= O_PATH;
+       }
+#endif
+
+       full_fname = full_path_from_dirfsp_atname(talloc_tos(),
+                                                 dirfsp,
+                                                 smb_fname);
+       if (full_fname == NULL) {
+               END_PROFILE(syscall_openat);
+               return -1;
+       }
+
+       if (fsp->fsp_flags.is_pathref && !have_opath) {
                become_root();
                became_root = true;
        }
 
-       if (how->flags & O_DIRECTORY) {
-               glfd = glfs_opendir(handle->data, smb_fname->base_name);
-       } else if (how->flags & O_CREAT) {
+       /*
+        * O_CREAT flag in open is handled differently in a way which is *NOT*
+        * safe against symlink race situations. We use glfs_creat() instead
+        * for correctness as glfs_openat() is broken with O_CREAT present
+        * in open flags.
+        */
+       if (flags & O_CREAT) {
+               if (fsp_get_pathref_fd(dirfsp) != AT_FDCWD) {
+                       /*
+                        * Replace smb_fname with full_path constructed above.
+                        */
+                       smb_fname = full_fname;
+               }
+
+               /*
+                * smb_fname can either be a full_path or the same one
+                * as received from the caller. In the latter case we
+                * are operating at current working directory.
+                */
                glfd = glfs_creat(handle->data,
                                  smb_fname->base_name,
-                                 how->flags,
+                                 flags,
                                  how->mode);
        } else {
-               glfd = glfs_open(handle->data,
-                                smb_fname->base_name,
-                                how->flags);
+               if (fsp_get_pathref_fd(dirfsp) != AT_FDCWD) {
+#ifdef HAVE_GFAPI_VER_7_11
+                       /*
+                        * Fetch Gluster fd for parent directory using dirfsp
+                        * before calling glfs_openat();
+                        */
+                       pglfd = vfs_gluster_fetch_glfd(handle, dirfsp);
+                       if (pglfd == NULL) {
+                               END_PROFILE(syscall_openat);
+                               DBG_ERR("Failed to fetch gluster fd\n");
+                               return -1;
+                       }
+
+                       glfd = glfs_openat(pglfd,
+                                          smb_fname->base_name,
+                                          flags,
+                                          how->mode);
+#else
+                       /*
+                        * Replace smb_fname with full_path constructed above.
+                        */
+                       smb_fname = full_fname;
+#endif
+               }
+
+               if (pglfd == NULL) {
+                       /*
+                        * smb_fname can either be a full_path or the same one
+                        * as received from the caller. In the latter case we
+                        * are operating at current working directory.
+                        */
+                       glfd = glfs_open(handle->data,
+                                        smb_fname->base_name,
+                                        flags);
+               }
        }
 
        if (became_root) {
                unbecome_root();
        }
 
+       TALLOC_FREE(full_fname);
+
        fsp->fsp_flags.have_proc_fds = false;
 
        if (glfd == NULL) {
-               TALLOC_FREE(name);
                END_PROFILE(syscall_openat);
                /* no extension destroy_fn, so no need to save errno */
                VFS_REMOVE_FSP_EXTENSION(handle, fsp);
@@ -838,7 +886,6 @@ static int vfs_gluster_openat(struct vfs_handle_struct *handle,
 
        *p_tmp = glfd;
 
-       TALLOC_FREE(name);
        END_PROFILE(syscall_openat);
        /* An arbitrary value for error reporting, so you know its us. */
        return 13371337;