+ if (!tvp) {
+ if (error_retry_count++ < MAX_ERROR_RETRY) {
+ tvp = vp;
+ continue;
+ }
+ error = ENOENT;
+ break;
+ }
+
+ if (tvp != start_vp) {
+ if (vp_with_iocount) {
+ vnode_put(vp_with_iocount);
+ vp_with_iocount = NULLVP;
+ }
+
+ error = vnode_getwithvid(tvp, vid);
+ if (error) {
+ if (error_retry_count++ < MAX_ERROR_RETRY) {
+ tvp = vp;
+ error = 0;
+ continue;
+ }
+ break;
+ }
+
+ vp_with_iocount = tvp;
+ }
+
+ bzero(&cn, sizeof(cn));
+ cn.cn_nameiop = LOOKUP;
+ cn.cn_flags = ISLASTCN | ISDOTDOT;
+ cn.cn_context = ctx;
+ cn.cn_pnbuf = &dotdotbuf[0];
+ cn.cn_pnlen = sizeof(dotdotbuf);
+ cn.cn_nameptr = cn.cn_pnbuf;
+ cn.cn_namelen = 2;
+
+ pvp = NULLVP;
+ if ((error = VNOP_LOOKUP(tvp, &pvp, &cn, ctx))) {
+ break;
+ }
+
+ if (!(tvp->v_flag & VISHARDLINK) && tvp->v_parent != pvp) {
+ (void)vnode_update_identity(tvp, pvp, NULL, 0, 0,
+ VNODE_UPDATE_PARENT);
+ }
+
+ if (vp_with_iocount) {
+ vnode_put(vp_with_iocount);
+ }
+
+ vp_with_iocount = tvp = pvp;
+ }
+
+ if (vp_with_iocount) {
+ vnode_put(vp_with_iocount);
+ }
+
+ return error;
+}
+
+/*
+ * This function builds the path in "buff" from the supplied vnode.
+ * The length of the buffer *INCLUDING* the trailing zero byte is
+ * returned in outlen. NOTE: the length includes the trailing zero
+ * byte and thus the length is one greater than what strlen would
+ * return. This is important and lots of code elsewhere in the kernel
+ * assumes this behavior.
+ *
+ * This function can call vnop in file system if the parent vnode
+ * does not exist or when called for hardlinks via volfs path.
+ * If BUILDPATH_NO_FS_ENTER is set in flags, it only uses values present
+ * in the name cache and does not enter the file system.
+ *
+ * If BUILDPATH_CHECK_MOVED is set in flags, we return EAGAIN when
+ * we encounter ENOENT during path reconstruction. ENOENT means that
+ * one of the parents moved while we were building the path. The
+ * caller can special handle this case by calling build_path again.
+ *
+ * If BUILDPATH_VOLUME_RELATIVE is set in flags, we return path
+ * that is relative to the nearest mount point, i.e. do not
+ * cross over mount points during building the path.
+ *
+ * passed in vp must have a valid io_count reference
+ *
+ * If parent vnode is non-NULL it also must have an io count. This
+ * allows build_path_with_parent to be safely called for operations
+ * unlink, rmdir and rename that already have io counts on the target
+ * and the directory. In this way build_path_with_parent does not have
+ * to try and obtain an additional io count on the parent. Taking an
+ * io count ont the parent can lead to dead lock if a forced unmount
+ * occures at the right moment. For a fuller explaination on how this
+ * can occur see the comment for vn_getpath_with_parent.
+ *
+ */
+int
+build_path_with_parent(vnode_t first_vp, vnode_t parent_vp, char *buff, int buflen, int *outlen, int flags, vfs_context_t ctx)
+{
+ vnode_t vp, tvp;
+ vnode_t vp_with_iocount;
+ vnode_t proc_root_dir_vp;
+ char *end;
+ const char *str;
+ int len;
+ int ret = 0;
+ int fixhardlink;
+
+ if (first_vp == NULLVP) {
+ return EINVAL;
+ }
+
+ if (buflen <= 1) {
+ return ENOSPC;
+ }
+
+ /*
+ * Grab the process fd so we can evaluate fd_rdir.
+ */
+ if (vfs_context_proc(ctx)->p_fd && !(flags & BUILDPATH_NO_PROCROOT)) {
+ proc_root_dir_vp = vfs_context_proc(ctx)->p_fd->fd_rdir;
+ } else {
+ proc_root_dir_vp = NULL;
+ }
+
+ vp_with_iocount = NULLVP;
+again:
+ vp = first_vp;
+
+ end = &buff[buflen - 1];
projects / apple / xnu.git / blobdiff