https://bugzilla.samba.org/show_bug.cgi?id=5820

           Summary: rsync does not replace symlink atomically
           Product: rsync
           Version: 3.0.4
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P3
         Component: core
        AssignedTo: [EMAIL PROTECTED]
        ReportedBy: [EMAIL PROTECTED]
         QAContact: [EMAIL PROTECTED]


rsync does not replace symlink atomically, i.e, first it unlinks an old symlink
and then creates a new symlink. There is short time when symlink does not exist
at all. The attached patch against 3.0.4 fixes the issue. However, it has been
tested on FreeBSD only. The patch is also available on
http://sysoev.ru/tmp/rsync.symlink.patch

--- generator.c 2008-08-31 20:51:29.000000000 +0400
+++ generator.c 2008-10-08 23:10:17.000000000 +0400
@@ -1556,9 +1556,40 @@
                                if (remove_source_files == 1)
                                        goto return_with_success;
                                goto cleanup;
+                       } else {
+                               char fnametmp[MAXPATHLEN];
+
+                               /* Replace the symlink atomically. */
+                               if (!get_tmpname(fnametmp, fname))
+                                       goto cleanup;
+                               if (!mktemp(fnametmp))
+                                       goto cleanup;
+                               if (do_symlink(sl, fnametmp) != 0) {
+                                       rsyserr(FERROR_XFER, errno, "symlink %s
-> \"%s\" failed",
+                                               full_fname(fnametmp), sl);
+                                       goto cleanup;
+                               }
+                               set_file_attrs(fnametmp, file, NULL, NULL, 0);
+                               if (do_rename(fnametmp, fname) != 0) {
+                                       rsyserr(FERROR_XFER, errno, "rename %s
-> %s failed",
+                                               full_fname(fnametmp),
full_fname(fname));
+                                       goto cleanup;
+                               }
+                               if (itemizing) {
+                                       itemize(fname, file, ndx, statret, &sx,
+                                              
ITEM_LOCAL_CHANGE|ITEM_REPORT_CHANGE, 0, NULL);
+                               }
+                               if (verbose)
+                                       rprintf(code, "%s -> %s\n", fname, sl);
+#ifdef SUPPORT_HARD_LINKS
+                               if (preserve_hard_links && F_IS_HLINKED(file))
+                                       finish_hard_link(file, fname, ndx,
NULL, itemizing, code, -1);
+#endif
+                               if (remove_source_files)
+                                       goto return_with_success;
+                               goto cleanup;
                        }
-                       /* Not the right symlink (or not a symlink), so
-                        * delete it. */
+                       /* Not not a symlink, so delete it. */
                        if (delete_item(fname, sx.st.st_mode, del_opts |
DEL_FOR_SYMLINK) != 0)
                                goto cleanup;
                } else if (basis_dir[0] != NULL) {


-- 
Configure bugmail: https://bugzilla.samba.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug, or are watching the QA contact.
-- 
Please use reply-all for most replies to avoid omitting the mailing list.
To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync
Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html

Reply via email to