2 * Backup handling code.
4 * Copyright (C) 1999 Andrew Tridgell
5 * Copyright (C) 2003-2009 Wayne Davison
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, visit the http://fsf.org website.
25 extern int preserve_acls;
26 extern int preserve_xattrs;
27 extern int preserve_devices;
28 extern int preserve_specials;
29 extern int preserve_links;
30 extern int safe_symlinks;
31 extern int backup_dir_len;
32 extern unsigned int backup_dir_remainder;
33 extern char backup_dir_buf[MAXPATHLEN];
34 extern char *backup_suffix;
35 extern char *backup_dir;
37 /* make a complete pathname for backup file */
38 char *get_backup_name(const char *fname)
41 if (stringjoin(backup_dir_buf + backup_dir_len, backup_dir_remainder,
42 fname, backup_suffix, NULL) < backup_dir_remainder)
43 return backup_dir_buf;
45 if (stringjoin(backup_dir_buf, MAXPATHLEN,
46 fname, backup_suffix, NULL) < MAXPATHLEN)
47 return backup_dir_buf;
50 rprintf(FERROR, "backup filename too long\n");
54 /****************************************************************************
55 Create a directory given an absolute path, perms based upon another directory
57 ****************************************************************************/
58 int make_bak_dir(const char *fullpath)
60 char fbuf[MAXPATHLEN], *rel, *end, *p;
61 struct file_struct *file;
62 int len = backup_dir_len;
65 while (*fullpath == '.' && fullpath[1] == '/') {
70 if (strlcpy(fbuf, fullpath, sizeof fbuf) >= sizeof fbuf)
74 end = p = rel + strlen(rel);
76 /* Try to find an existing dir, starting from the deepest dir. */
82 if (mkdir_defmode(fbuf) == 0)
84 if (errno != ENOENT) {
85 rsyserr(FERROR, errno,
86 "make_bak_dir mkdir %s failed",
93 /* Make all the dirs that we didn't find on the way here. */
96 /* Try to transfer the directory settings of the
97 * actual dir that the files are coming from. */
99 if (x_stat(rel, &sx.st, NULL) < 0) {
100 rsyserr(FERROR, errno,
101 "make_bak_dir stat %s failed",
104 if (!(file = make_file(rel, NULL, NULL, 0, NO_FILTERS)))
107 if (preserve_acls && !S_ISLNK(file->mode)) {
109 cache_acl(file, &sx);
113 #ifdef SUPPORT_XATTRS
114 if (preserve_xattrs) {
116 cache_xattr(file, &sx);
120 set_file_attrs(fbuf, file, NULL, NULL, 0);
128 if (mkdir_defmode(fbuf) < 0) {
129 rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
138 /* Has same return codes as make_backup(). */
139 static inline int link_or_rename(const char *from, const char *to,
140 BOOL prefer_rename, STRUCT_STAT *stp)
142 if (S_ISLNK(stp->st_mode)) {
145 #ifndef CAN_HARDLINK_SYMLINK
146 return 0; /* Use copy code. */
149 if (IS_SPECIAL(stp->st_mode) || IS_DEVICE(stp->st_mode)) {
152 #ifndef CAN_HARDLINK_SPECIAL
153 return 0; /* Use copy code. */
156 #ifdef SUPPORT_HARD_LINKS
157 if (!S_ISDIR(stp->st_mode)) {
158 if (do_link(from, to) == 0)
164 if (do_rename(from, to) == 0) {
165 if (stp->st_nlink > 1 && !S_ISDIR(stp->st_mode)) {
166 /* If someone has hard-linked the file into the backup
167 * dir, rename() might return success but do nothing! */
168 robust_unlink(to); /* Just in case... */
175 /* Hard-link, rename, or copy an item to the backup name. Returns 2 if item
176 * was duplicated into backup area, 1 if item was moved, or 0 for failure.*/
177 int make_backup(const char *fname, BOOL prefer_rename)
180 struct file_struct *file;
181 int save_preserve_xattrs;
182 char *buf = get_backup_name(fname);
189 /* Return success if no file to keep. */
190 if (x_lstat(fname, &sx.st, NULL) < 0)
193 /* Try a hard-link or a rename first. Using rename is not atomic, but
194 * is more efficient than forcing a copy for larger files when no hard-
195 * linking is possible. */
196 if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
198 if (errno == EEXIST) {
200 if (do_lstat(buf, &bakst) == 0) {
201 int flags = get_del_for_flag(bakst.st_mode) | DEL_FOR_BACKUP | DEL_RECURSE;
202 if (delete_item(buf, bakst.st_mode, flags) != 0)
205 if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
207 } else if (backup_dir && errno == ENOENT) {
208 /* If the backup dir is missing, try again after making it. */
209 if (make_bak_dir(buf) != 0)
211 if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
215 /* Fall back to making a copy. */
216 if (!(file = make_file(fname, NULL, &sx.st, 0, NO_FILTERS)))
217 return 1; /* the file could have disappeared */
220 if (preserve_acls && !S_ISLNK(file->mode)) {
222 cache_acl(file, &sx);
226 #ifdef SUPPORT_XATTRS
227 if (preserve_xattrs) {
228 get_xattr(fname, &sx);
229 cache_xattr(file, &sx);
234 /* Check to see if this is a device file, or link */
235 if ((am_root && preserve_devices && IS_DEVICE(file->mode))
236 || (preserve_specials && IS_SPECIAL(file->mode))) {
238 if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0) {
239 save_errno = errno ? errno : EINVAL; /* 0 paranoia */
240 if (errno == ENOENT && make_bak_dir(buf) == 0) {
241 if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0)
242 save_errno = errno ? errno : save_errno;
247 rsyserr(FERROR, save_errno, "mknod %s failed",
252 if (DEBUG_GTE(BACKUP, 1) && save_errno == 0) {
253 rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
259 if (!ret && S_ISDIR(file->mode)) {
261 /* make an empty directory */
262 if (do_mkdir(buf, file->mode) < 0) {
263 int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
264 if (errno == ENOENT && make_bak_dir(buf) == 0) {
265 if (do_mkdir(buf, file->mode) < 0)
266 save_errno = errno ? errno : save_errno;
271 rsyserr(FINFO, save_errno, "mkdir %s failed",
276 ret_code = do_rmdir(fname);
277 if (DEBUG_GTE(BACKUP, 1)) {
278 rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
279 full_fname(fname), ret_code);
285 if (!ret && preserve_links && S_ISLNK(file->mode)) {
286 const char *sl = F_SYMLINK(file);
287 if (safe_symlinks && unsafe_symlink(sl, fname)) {
288 if (INFO_GTE(SYMSAFE, 1)) {
289 rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
290 full_fname(buf), sl);
294 if (do_symlink(sl, buf) < 0) {
295 int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
296 if (errno == ENOENT && make_bak_dir(buf) == 0) {
297 if (do_symlink(sl, buf) < 0)
298 save_errno = errno ? errno : save_errno;
303 rsyserr(FERROR, save_errno, "link %s -> \"%s\"",
304 full_fname(buf), sl);
312 if (!ret && !S_ISREG(file->mode)) {
313 rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
319 /* Copy to backup tree if a file. */
321 if (copy_file(fname, buf, -1, file->mode, 1) < 0) {
322 rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
323 full_fname(fname), buf);
330 save_preserve_xattrs = preserve_xattrs;
332 set_file_attrs(buf, file, NULL, fname, 0);
333 preserve_xattrs = save_preserve_xattrs;
338 if (INFO_GTE(BACKUP, 1)) {
339 rprintf(FINFO, "backed up %s to %s\n",