X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/65d6212d03fff0bc5a9b9c9c0fbaa7bc7ffd2c7c..cb197514d99d17dc3a1ce26ff8918d63307d75e4:/backup.c

diff --git a/backup.c b/backup.c
index a4572d39..5805f16a 100644
--- a/backup.c
+++ b/backup.c
@@ -1,294 +1,367 @@
 /*
-   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"
-
-extern int verbose;
-extern int backup_suffix_len;
-extern int backup_dir_len;
-extern char *backup_suffix;
-extern char *backup_dir;
+#include "ifuncs.h"
 
 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 preserve_hard_links;
-extern int orig_umask;
+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;
 
-/* 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;
 }
 
-
-/* recursively make a directory path */
-static int make_dir(char *name, int mask)
-{
-	char newdir [MAXPATHLEN];
-	char *p, *d;
-
-	/* copy pathname over, look for last '/' */
-	for (p = d = newdir; *name; *d++ = *name++)
-		if (*name == '/')
-			p = d;
-	if (p == newdir)
-		return 0;
-	*p = 0;
-
-	/* make the new directory, if that fails then make its parent */
-	while (do_mkdir(newdir, mask) != 0) {
-		if (errno != ENOENT || !make_dir(newdir, mask))
-			return 0;
-	}
-
-	return 1;
-} /* make_dir */
-
-
 /****************************************************************************
 Create a directory given an absolute path, perms based upon another directory
 path
 ****************************************************************************/
-static int make_bak_dir(char *fname, char *bak_path)
+int make_bak_dir(const char *fullpath)
 {
-	STRUCT_STAT st;
-	STRUCT_STAT *st2;
-	char fullpath[MAXPATHLEN];
-	char *p;
-	char *q;
+	char fbuf[MAXPATHLEN], *rel, *end, *p;
+	struct file_struct *file;
+	int len = backup_dir_len;
+	stat_x sx;
 
-	while(strncmp(bak_path, "./", 2) == 0) bak_path += 2;
+	while (*fullpath == '.' && fullpath[1] == '/') {
+		fullpath += 2;
+		len -= 2;
+	}
 
-	if (pathjoin(fullpath, sizeof fullpath, bak_path, fname)
-	    >= sizeof fullpath) {
-		rprintf(FERROR, "backup dirname too long\n");
-		return 0;
+	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 == fbuf)
+			return -1;
+		if (*p == '/') {
+			*p = '\0';
+			if (mkdir_defmode(fbuf) == 0)
+				break;
+			if (errno != ENOENT) {
+				rsyserr(FERROR, errno,
+					"make_bak_dir mkdir %s failed",
+					full_fname(fbuf));
+				return -1;
+			}
+		}
 	}
-	p = fullpath;
-	q = fullpath + strlen(bak_path);
-	if (*q == '/')
-		q++; /* Point past the middle '/' added by pathjoin(). */
 
-	/* Make the directories */
-	while ((p = strchr(p, '/')) != NULL) {
-		*p = 0;
-		if (do_lstat(fullpath, &st) != 0) {
-			do_mkdir(fullpath, 0777 & ~orig_umask);
-			if (p > q) {
-				if (do_lstat(q, &st) != 0) {
-					rprintf(FERROR, "make_bak_dir stat %s failed: %s\n",
-						full_fname(fullpath), strerror(errno));
-				} else {
-					st2 = &st;
-					set_modtime(fullpath, st2->st_mtime);
-					if (do_lchown(fullpath, st2->st_uid, st2->st_gid) != 0) {
-						rprintf(FERROR, "make_bak_dir chown %s failed: %s\n",
-							full_fname(fullpath), strerror(errno));
-					}
-					if (do_chmod(fullpath, st2->st_mode) != 0) {
-						rprintf(FERROR, "make_bak_dir failed to set permissions on %s: %s\n",
-							full_fname(fullpath), strerror(errno));
-					}
+	/* Make all the dirs that we didn't find on the way here. */
+	while (1) {
+		if (p >= rel) {
+			/* Try to transfer the directory settings of the
+			 * actual dir that the files are coming from. */
+			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 {
+				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 = '/';
+		p += strlen(p);
+		if (p == end)
+			break;
+		if (mkdir_defmode(fbuf) < 0) {
+			rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
+				full_fname(fbuf));
+			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)
 {
-	int keep_trying = 4;
-	int keep_path_extfs = 0;
-	int failed;
-
-	while (keep_trying) {
-		if (keep_path_extfs) {
-			failed = copy_file(src, dst, 0755);
-			if (!failed)
-				do_unlink(src);
-		} else
-			failed = robust_rename(src, dst);
-
-		if (failed) {
-			if (verbose > 2) {
-				rprintf(FERROR, "robust_move failed: %s(%d)\n",
-					strerror(errno), errno);
-			}
-			switch (errno) {
-			case EXDEV:	/* external filesystem */
-				keep_path_extfs = 1;
-				keep_trying--;
-				break;
-			case ENOENT:	/* no directory to write to */
-				make_dir(dst, 0700);
-				keep_trying--;
-				break;
-			default:
-				keep_trying = 0;
-				break;
-			}
-		} else
-			keep_trying = 0;
-	} /* while */
-	return !failed;
-} /* robust_move */
-
+	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)
 {
-	static int initialised;
-	char keep_name[MAXPATHLEN];
-	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;
 
-	if (!initialised) {
-		if (backup_dir_len && backup_dir[backup_dir_len - 1] == '/')
-			backup_dir[--backup_dir_len] = '\0';
-		if (verbose > 0)
-			rprintf(FINFO, "backup_dir is %s\n", backup_dir);
+	if (!buf)
+		return 0;
 
-		initialised = 1;
+	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;
 	}
 
-	/* 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
-
-	file = make_file(fname, NULL, NO_EXCLUDES);
-
-	/* 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(keep_name, sizeof keep_name,
-		       backup_dir, "/", fname, backup_suffix, NULL)
-	    >= sizeof keep_name) {
-		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(fname, backup_dir);
-			if (do_mknod(keep_name, file->mode, file->u.rdev) != 0) {
-				rprintf(FERROR, "mknod %s failed: %s\n",
-					full_fname(keep_name), 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(fname, backup_dir);
-		do_mkdir(keep_name, 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, keep_name)) {
-			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(keep_name), file->u.link);
+					full_fname(buf), sl);
 			}
-			kept = 1;
-		}
-		make_bak_dir(fname, backup_dir);
-		if (do_symlink(file->u.link, keep_name) != 0) {
-			rprintf(FERROR, "link %s -> %s : %s\n",
-				full_fname(keep_name), 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, keep_name)) {
-			rprintf(FERROR, "keep_backup failed: %s -> \"%s\": %s\n",
-				full_fname(fname), keep_name, 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(keep_name, file, NULL, 0);
-	free(file);
 
-	if (verbose > 1)
-		rprintf(FINFO, "keep_backup %s -> %s\n", fname, keep_name);
-	return 1;
-} /* keep_backup */
+	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;
 }