Fixed an ACL/xattr corruption issue where the --backup option could cause
[rsync/rsync.git] / backup.c
index 2078861..5805f16 100644 (file)
--- a/backup.c
+++ b/backup.c
@@ -1,92 +1,91 @@
 /*
-   Copyright (C) Andrew Tridgell 1999
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
  You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-/* backup handling code */
+ * Backup handling code.
+ *
+ * Copyright (C) 1999 Andrew Tridgell
+ * Copyright (C) 2003-2009 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
 
 #include "rsync.h"
+#include "ifuncs.h"
 
-extern int verbose;
-extern int backup_suffix_len;
+extern int am_root;
+extern int preserve_acls;
+extern int preserve_xattrs;
+extern int preserve_devices;
+extern int preserve_specials;
+extern int preserve_links;
+extern int safe_symlinks;
 extern int backup_dir_len;
 extern unsigned int backup_dir_remainder;
 extern char backup_dir_buf[MAXPATHLEN];
 extern char *backup_suffix;
 extern char *backup_dir;
 
-extern int am_root;
-extern int preserve_devices;
-extern int preserve_links;
-extern int preserve_hard_links;
-extern int orig_umask;
-
-/* simple backup creates a backup with a suffix in the same directory */
-static int make_simple_backup(char *fname)
+/* make a complete pathname for backup file */
+char *get_backup_name(const char *fname)
 {
-       char fnamebak[MAXPATHLEN];
-
-       if (stringjoin(fnamebak, sizeof fnamebak, fname, backup_suffix, NULL)
-           >= sizeof fnamebak) {
-               rprintf(FERROR, "backup filename too long\n");
-               return 0;
+       if (backup_dir) {
+               if (stringjoin(backup_dir_buf + backup_dir_len, backup_dir_remainder,
+                              fname, backup_suffix, NULL) < backup_dir_remainder)
+                       return backup_dir_buf;
+       } else {
+               if (stringjoin(backup_dir_buf, MAXPATHLEN,
+                              fname, backup_suffix, NULL) < MAXPATHLEN)
+                       return backup_dir_buf;
        }
 
-       if (do_rename(fname, fnamebak) != 0) {
-               /* cygwin (at least version b19) reports EINVAL */
-               if (errno != ENOENT && errno != EINVAL) {
-                       rsyserr(FERROR, errno, "rename %s to backup %s", fname, fnamebak);
-                       return 0;
-               }
-       } else if (verbose > 1) {
-               rprintf(FINFO, "backed up %s to %s\n", fname, fnamebak);
-       }
-       return 1;
+       rprintf(FERROR, "backup filename too long\n");
+       return NULL;
 }
 
-
 /****************************************************************************
 Create a directory given an absolute path, perms based upon another directory
 path
 ****************************************************************************/
-static int make_bak_dir(char *fullpath)
+int make_bak_dir(const char *fullpath)
 {
-       STRUCT_STAT st;
-       char *rel = fullpath + backup_dir_len;
-       char *end = rel + strlen(rel);
-       char *p = end;
+       char fbuf[MAXPATHLEN], *rel, *end, *p;
+       struct file_struct *file;
+       int len = backup_dir_len;
+       stat_x sx;
 
-       while (strncmp(fullpath, "./", 2) == 0)
+       while (*fullpath == '.' && fullpath[1] == '/') {
                fullpath += 2;
+               len -= 2;
+       }
+
+       if (strlcpy(fbuf, fullpath, sizeof fbuf) >= sizeof fbuf)
+               return -1;
+
+       rel = fbuf + len;
+       end = p = rel + strlen(rel);
 
        /* Try to find an existing dir, starting from the deepest dir. */
        while (1) {
-               if (--p == fullpath) {
-                       p += strlen(p);
-                       goto failure;
-               }
+               if (--p == fbuf)
+                       return -1;
                if (*p == '/') {
                        *p = '\0';
-                       if (do_mkdir(fullpath, 0777 & ~orig_umask) == 0)
+                       if (mkdir_defmode(fbuf) == 0)
                                break;
                        if (errno != ENOENT) {
-                               rprintf(FERROR,
-                                   "make_bak_dir mkdir %s failed: %s\n",
-                                   full_fname(fullpath), strerror(errno));
-                               goto failure;
+                               rsyserr(FERROR, errno,
+                                       "make_bak_dir mkdir %s failed",
+                                       full_fname(fbuf));
+                               return -1;
                        }
                }
        }
@@ -96,152 +95,273 @@ static int make_bak_dir(char *fullpath)
                if (p >= rel) {
                        /* Try to transfer the directory settings of the
                         * actual dir that the files are coming from. */
-                       if (do_lstat(rel, &st) != 0) {
-                               rprintf(FERROR,
-                                   "make_bak_dir stat %s failed: %s\n",
-                                   full_fname(rel), strerror(errno));
+                       init_stat_x(&sx);
+                       if (x_stat(rel, &sx.st, NULL) < 0) {
+                               rsyserr(FERROR, errno,
+                                       "make_bak_dir stat %s failed",
+                                       full_fname(rel));
                        } else {
-                               set_modtime(fullpath, st.st_mtime);
-                               do_lchown(fullpath, st.st_uid, st.st_gid);
-                               do_chmod(fullpath, st.st_mode);
+                               if (!(file = make_file(rel, NULL, NULL, 0, NO_FILTERS)))
+                                       continue;
+#ifdef SUPPORT_ACLS
+                               if (preserve_acls && !S_ISLNK(file->mode)) {
+                                       get_acl(rel, &sx);
+                                       cache_tmp_acl(file, &sx);
+                                       free_acl(&sx);
+                               }
+#endif
+#ifdef SUPPORT_XATTRS
+                               if (preserve_xattrs) {
+                                       get_xattr(rel, &sx);
+                                       cache_tmp_xattr(file, &sx);
+                                       free_xattr(&sx);
+                               }
+#endif
+                               set_file_attrs(fbuf, file, NULL, NULL, 0);
+                               unmake_file(file);
+#ifdef SUPPORT_ACLS
+                               uncache_tmp_acls();
+#endif
+#ifdef SUPPORT_XATTRS
+                               uncache_tmp_xattrs();
+#endif
                        }
                }
                *p = '/';
                p += strlen(p);
                if (p == end)
                        break;
-               if (do_mkdir(fullpath, 0777 & ~orig_umask) < 0) {
-                       rprintf(FERROR,
-                           "make_bak_dir mkdir %s failed: %s\n",
-                           full_fname(fullpath), strerror(errno));
-                       goto failure;
+               if (mkdir_defmode(fbuf) < 0) {
+                       rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
+                               full_fname(fbuf));
+                       return -1;
                }
        }
-       return 0;
 
-failure:
-       while (p != end) {
-               *p = '/';
-               p += strlen(p);
-       }
-       return -1;
+       return 0;
 }
 
-/* robustly move a file, creating new directory structures if necessary */
-static int robust_move(char *src, char *dst)
+/* Has same return codes as make_backup(). */
+static inline int link_or_rename(const char *from, const char *to,
+                                BOOL prefer_rename, STRUCT_STAT *stp)
 {
-       if (robust_rename(src, dst, 0755) != 0 || errno != ENOENT
-           || make_bak_dir(dst) < 0 || robust_rename(src, dst, 0755) != 0)
-               return -1;
+       if (S_ISLNK(stp->st_mode)) {
+               if (prefer_rename)
+                       goto do_rename;
+#ifndef CAN_HARDLINK_SYMLINK
+               return 0; /* Use copy code. */
+#endif
+       }
+       if (IS_SPECIAL(stp->st_mode) || IS_DEVICE(stp->st_mode)) {
+               if (prefer_rename)
+                       goto do_rename;
+#ifndef CAN_HARDLINK_SPECIAL
+               return 0; /* Use copy code. */
+#endif
+       }
+#ifdef SUPPORT_HARD_LINKS
+       if (!S_ISDIR(stp->st_mode)) {
+               if (do_link(from, to) == 0)
+                       return 2;
+               return 0;
+       }
+#endif
+  do_rename:
+       if (do_rename(from, to) == 0) {
+               if (stp->st_nlink > 1 && !S_ISDIR(stp->st_mode)) {
+                       /* If someone has hard-linked the file into the backup
+                        * dir, rename() might return success but do nothing! */
+                       robust_unlink(to); /* Just in case... */
+               }
+               return 1;
+       }
        return 0;
 }
 
-
-/* If we have a --backup-dir, then we get here from make_backup().
- * We will move the file to be deleted into a parallel directory tree. */
-static int keep_backup(char *fname)
+/* Hard-link, rename, or copy an item to the backup name.  Returns 2 if item
+ * was duplicated into backup area, 1 if item was moved, or 0 for failure.*/
+int make_backup(const char *fname, BOOL prefer_rename)
 {
-       STRUCT_STAT st;
+       stat_x sx;
        struct file_struct *file;
-       int kept = 0;
-       int ret_code;
+       int save_preserve_xattrs;
+       char *buf = get_backup_name(fname);
+       int ret = 0;
 
-       /* return if no file to keep */
-#if SUPPORT_LINKS
-       if (do_lstat(fname, &st)) return 1;
-#else
-       if (do_stat(fname, &st)) return 1;
-#endif
+       if (!buf)
+               return 0;
 
-       file = make_file(fname, NULL, NO_EXCLUDES);
+       init_stat_x(&sx);
+       /* Return success if no file to keep. */
+       if (x_lstat(fname, &sx.st, NULL) < 0)
+               return 1;
+
+       /* Try a hard-link or a rename first.  Using rename is not atomic, but
+        * is more efficient than forcing a copy for larger files when no hard-
+        * linking is possible. */
+       if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
+               goto success;
+       if (errno == EEXIST) {
+               STRUCT_STAT bakst;
+               if (do_lstat(buf, &bakst) == 0) {
+                       int flags = get_del_for_flag(bakst.st_mode) | DEL_FOR_BACKUP | DEL_RECURSE;
+                       if (delete_item(buf, bakst.st_mode, flags) != 0)
+                               return 0;
+               }
+               if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
+                       goto success;
+       } else if (backup_dir && errno == ENOENT) {
+               /* If the backup dir is missing, try again after making it. */
+               if (make_bak_dir(buf) != 0)
+                       return 0;
+               if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
+                       goto success;
+       }
 
-       /* the file could have disappeared */
-       if (!file) return 1;
+       /* Fall back to making a copy. */
+       if (!(file = make_file(fname, NULL, &sx.st, 0, NO_FILTERS)))
+               return 1; /* the file could have disappeared */
 
-       /* make a complete pathname for backup file */
-       if (stringjoin(backup_dir_buf + backup_dir_len, backup_dir_remainder,
-           fname, backup_suffix, NULL) >= backup_dir_remainder) {
-               rprintf(FERROR, "keep_backup filename too long\n");
-               return 0;
+#ifdef SUPPORT_ACLS
+       if (preserve_acls && !S_ISLNK(file->mode)) {
+               get_acl(fname, &sx);
+               cache_tmp_acl(file, &sx);
+               free_acl(&sx);
        }
+#endif
+#ifdef SUPPORT_XATTRS
+       if (preserve_xattrs) {
+               get_xattr(fname, &sx);
+               cache_tmp_xattr(file, &sx);
+               free_xattr(&sx);
+       }
+#endif
 
-#ifdef HAVE_MKNOD
        /* Check to see if this is a device file, or link */
-       if (IS_DEVICE(file->mode)) {
-               if (am_root && preserve_devices) {
-                       make_bak_dir(backup_dir_buf);
-                       if (do_mknod(backup_dir_buf, file->mode, file->u.rdev) != 0) {
-                               rprintf(FERROR, "mknod %s failed: %s\n",
-                                       full_fname(backup_dir_buf), strerror(errno));
-                       } else if (verbose > 2) {
-                               rprintf(FINFO,
-                                       "make_backup: DEVICE %s successful.\n",
-                                       fname);
+       if ((am_root && preserve_devices && IS_DEVICE(file->mode))
+        || (preserve_specials && IS_SPECIAL(file->mode))) {
+               int save_errno;
+               if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0) {
+                       save_errno = errno ? errno : EINVAL; /* 0 paranoia */
+                       if (errno == ENOENT && make_bak_dir(buf) == 0) {
+                               if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0)
+                                       save_errno = errno ? errno : save_errno;
+                               else
+                                       save_errno = 0;
                        }
+                       if (save_errno) {
+                               rsyserr(FERROR, save_errno, "mknod %s failed",
+                                       full_fname(buf));
+                       }
+               } else
+                       save_errno = 0;
+               if (DEBUG_GTE(BACKUP, 1) && save_errno == 0) {
+                       rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
+                               fname);
                }
-               kept = 1;
-               do_unlink(fname);
+               ret = 2;
        }
-#endif
 
-       if (!kept && S_ISDIR(file->mode)) {
+       if (!ret && S_ISDIR(file->mode)) {
+               int ret_code;
                /* make an empty directory */
-               make_bak_dir(backup_dir_buf);
-               do_mkdir(backup_dir_buf, file->mode);
-               ret_code = do_rmdir(fname);
+               if (do_mkdir(buf, file->mode) < 0) {
+                       int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
+                       if (errno == ENOENT && make_bak_dir(buf) == 0) {
+                               if (do_mkdir(buf, file->mode) < 0)
+                                       save_errno = errno ? errno : save_errno;
+                               else
+                                       save_errno = 0;
+                       }
+                       if (save_errno) {
+                               rsyserr(FINFO, save_errno, "mkdir %s failed",
+                                       full_fname(buf));
+                       }
+               }
 
-               if (verbose > 2) {
+               ret_code = do_rmdir(fname);
+               if (DEBUG_GTE(BACKUP, 1)) {
                        rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
                                full_fname(fname), ret_code);
                }
-               kept = 1;
+               ret = 2;
        }
 
-#if SUPPORT_LINKS
-       if (!kept && preserve_links && S_ISLNK(file->mode)) {
-               extern int safe_symlinks;
-               if (safe_symlinks && unsafe_symlink(file->u.link, backup_dir_buf)) {
-                       if (verbose) {
+#ifdef SUPPORT_LINKS
+       if (!ret && preserve_links && S_ISLNK(file->mode)) {
+               const char *sl = F_SYMLINK(file);
+               if (safe_symlinks && unsafe_symlink(sl, fname)) {
+                       if (INFO_GTE(SYMSAFE, 1)) {
                                rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
-                                       full_fname(backup_dir_buf), file->u.link);
+                                       full_fname(buf), sl);
                        }
-                       kept = 1;
-               }
-               make_bak_dir(backup_dir_buf);
-               if (do_symlink(file->u.link, backup_dir_buf) != 0) {
-                       rprintf(FERROR, "link %s -> %s : %s\n",
-                               full_fname(backup_dir_buf), file->u.link, strerror(errno));
+                       ret = 2;
+               } else {
+                       if (do_symlink(sl, buf) < 0) {
+                               int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
+                               if (errno == ENOENT && make_bak_dir(buf) == 0) {
+                                       if (do_symlink(sl, buf) < 0)
+                                               save_errno = errno ? errno : save_errno;
+                                       else
+                                               save_errno = 0;
+                               }
+                               if (save_errno) {
+                                       rsyserr(FERROR, save_errno, "link %s -> \"%s\"",
+                                               full_fname(buf), sl);
+                               }
+                       }
+                       ret = 2;
                }
-               do_unlink(fname);
-               kept = 1;
        }
 #endif
 
-       if (!kept && !S_ISREG(file->mode)) {
+       if (!ret && !S_ISREG(file->mode)) {
                rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
                        fname);
+               unmake_file(file);
+#ifdef SUPPORT_ACLS
+               uncache_tmp_acls();
+#endif
+#ifdef SUPPORT_XATTRS
+               uncache_tmp_xattrs();
+#endif
+               return 2;
        }
 
-       /* move to keep tree if a file */
-       if (!kept) {
-               if (!robust_move(fname, backup_dir_buf)) {
-                       rprintf(FERROR, "keep_backup failed: %s -> \"%s\": %s\n",
-                               full_fname(fname), backup_dir_buf, strerror(errno));
+       /* Copy to backup tree if a file. */
+       if (!ret) {
+               if (copy_file(fname, buf, -1, file->mode, 1) < 0) {
+                       rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
+                               full_fname(fname), buf);
+                       unmake_file(file);
+#ifdef SUPPORT_ACLS
+                       uncache_tmp_acls();
+#endif
+#ifdef SUPPORT_XATTRS
+                       uncache_tmp_xattrs();
+#endif
+                       return 0;
                }
+               ret = 2;
        }
-       set_perms(backup_dir_buf, file, NULL, 0);
-       free(file);
 
-       if (verbose > 1)
-               rprintf(FINFO, "keep_backup %s -> %s\n", fname, backup_dir_buf);
-       return 1;
-}
+       save_preserve_xattrs = preserve_xattrs;
+       preserve_xattrs = 0;
+       set_file_attrs(buf, file, NULL, fname, 0);
+       preserve_xattrs = save_preserve_xattrs;
 
+       unmake_file(file);
+#ifdef SUPPORT_ACLS
+       uncache_tmp_acls();
+#endif
+#ifdef SUPPORT_XATTRS
+       uncache_tmp_xattrs();
+#endif
 
-/* main backup switch routine */
-int make_backup(char *fname)
-{
-       if (backup_dir)
-               return keep_backup(fname);
-       return make_simple_backup(fname);
+  success:
+       if (INFO_GTE(BACKUP, 1)) {
+               rprintf(FINFO, "backed up %s to %s\n",
+                       fname, buf);
+       }
+       return ret;
 }