X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/3d19b4c83edab707de2ddf91b1469befc12de54e..9439c0cb5a4b020b9bfcfe0351e33c17b9c53b54:/backup.c

diff --git a/backup.c b/backup.c
index 54d5fae8..7189a5c2 100644
--- a/backup.c
+++ b/backup.c
@@ -1,46 +1,329 @@
-/* 
-   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) 2003-2007 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.,
+ * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
+ */
 
 #include "rsync.h"
 
 extern int verbose;
+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;
 
+/* make a complete pathname for backup file */
+char *get_backup_name(const char *fname)
+{
+	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;
+	}
+
+	rprintf(FERROR, "backup filename too long\n");
+	return NULL;
+}
 
-int make_backup(char *fname)
+/* simple backup creates a backup with a suffix in the same directory */
+static int make_simple_backup(const char *fname)
 {
-	char fnamebak[MAXPATHLEN];
-	if (strlen(fname) + strlen(backup_suffix) > (MAXPATHLEN-1)) {
-		rprintf(FERROR,"backup filename too long\n");
+	int rename_errno;
+	const char *fnamebak = get_backup_name(fname);
+
+	if (!fnamebak)
 		return 0;
-	}
 
-	slprintf(fnamebak,sizeof(fnamebak),"%s%s",fname,backup_suffix);
-	if (do_rename(fname,fnamebak) != 0) {
+	while (1) {
+		if (do_rename(fname, fnamebak) == 0) {
+			if (verbose > 1) {
+				rprintf(FINFO, "backed up %s to %s\n",
+					fname, fnamebak);
+			}
+			break;
+		}
 		/* cygwin (at least version b19) reports EINVAL */
-		if (errno != ENOENT && errno != EINVAL) {
-			rprintf(FERROR,"rename %s %s : %s\n",fname,fnamebak,strerror(errno));
-			return 0;
+		if (errno == ENOENT || errno == EINVAL)
+			break;
+
+		rename_errno = errno;
+		if (errno == EISDIR && do_rmdir(fnamebak) == 0)
+			continue;
+		if (errno == ENOTDIR && do_unlink(fnamebak) == 0)
+			continue;
+
+		rsyserr(FERROR, rename_errno, "rename %s to backup %s",
+			fname, fnamebak);
+		errno = rename_errno;
+		return 0;
+	}
+
+	return 1;
+}
+
+
+/****************************************************************************
+Create a directory given an absolute path, perms based upon another directory
+path
+****************************************************************************/
+static int make_bak_dir(char *fullpath)
+{
+	statx sx;
+	struct file_struct *file;
+	char *rel = fullpath + backup_dir_len;
+	char *end = rel + strlen(rel);
+	char *p = end;
+
+	while (strncmp(fullpath, "./", 2) == 0)
+		fullpath += 2;
+
+	/* Try to find an existing dir, starting from the deepest dir. */
+	while (1) {
+		if (--p == fullpath) {
+			p += strlen(p);
+			goto failure;
+		}
+		if (*p == '/') {
+			*p = '\0';
+			if (mkdir_defmode(fullpath) == 0)
+				break;
+			if (errno != ENOENT) {
+				rsyserr(FERROR, errno,
+					"make_bak_dir mkdir %s failed",
+					full_fname(fullpath));
+				goto failure;
+			}
+		}
+	}
+
+	/* 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. */
+			if (x_stat(rel, &sx.st, NULL) < 0) {
+				rsyserr(FERROR, errno,
+					"make_bak_dir stat %s failed",
+					full_fname(rel));
+			} else {
+#ifdef SUPPORT_ACLS
+				sx.acc_acl = sx.def_acl = NULL;
+#endif
+#ifdef SUPPORT_XATTRS
+				sx.xattr = NULL;
+#endif
+				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_acl(file, &sx);
+					free_acl(&sx);
+				}
+#endif
+#ifdef SUPPORT_XATTRS
+				if (preserve_xattrs) {
+					get_xattr(rel, &sx);
+					cache_xattr(file, &sx);
+					free_xattr(&sx);
+				}
+#endif
+				set_file_attrs(fullpath, file, NULL, NULL, 0);
+				free(file);
+			}
+		}
+		*p = '/';
+		p += strlen(p);
+		if (p == end)
+			break;
+		if (mkdir_defmode(fullpath) < 0) {
+			rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
+				full_fname(fullpath));
+			goto failure;
 		}
-	} else if (verbose > 1) {
-		rprintf(FINFO,"backed up %s to %s\n",fname,fnamebak);
+	}
+	return 0;
+
+  failure:
+	while (p != end) {
+		*p = '/';
+		p += strlen(p);
+	}
+	return -1;
+}
+
+/* robustly move a file, creating new directory structures if necessary */
+static int robust_move(const char *src, char *dst)
+{
+	if (robust_rename(src, dst, NULL, 0755) < 0
+	 && (errno != ENOENT || make_bak_dir(dst) < 0
+	  || robust_rename(src, dst, NULL, 0755) < 0))
+		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(const char *fname)
+{
+	statx sx;
+	struct file_struct *file;
+	char *buf;
+	int kept = 0;
+	int ret_code;
+
+	/* return if no file to keep */
+	if (x_lstat(fname, &sx.st, NULL) < 0)
+		return 1;
+#ifdef SUPPORT_ACLS
+	sx.acc_acl = sx.def_acl = NULL;
+#endif
+#ifdef SUPPORT_XATTRS
+	sx.xattr = NULL;
+#endif
+
+	if (!(file = make_file(fname, NULL, NULL, 0, NO_FILTERS)))
+		return 1; /* the file could have disappeared */
+
+	if (!(buf = get_backup_name(fname))) {
+		unmake_file(file);
+		return 0;
+	}
+
+#ifdef SUPPORT_ACLS
+	if (preserve_acls && !S_ISLNK(file->mode)) {
+		get_acl(fname, &sx);
+		cache_acl(file, &sx);
+		free_acl(&sx);
+	}
+#endif
+#ifdef SUPPORT_XATTRS
+	if (preserve_xattrs) {
+		get_xattr(fname, &sx);
+		cache_xattr(file, &sx);
+		free_xattr(&sx);
+	}
+#endif
+
+	/* Check to see if this is a device file, or link */
+	if ((am_root && preserve_devices && IS_DEVICE(file->mode))
+	 || (preserve_specials && IS_SPECIAL(file->mode))) {
+		uint32 *devp = F_RDEV_P(file);
+		dev_t rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
+		do_unlink(buf);
+		if (do_mknod(buf, file->mode, rdev) < 0
+		    && (errno != ENOENT || make_bak_dir(buf) < 0
+		     || do_mknod(buf, file->mode, rdev) < 0)) {
+			rsyserr(FERROR, errno, "mknod %s failed",
+				full_fname(buf));
+		} else if (verbose > 2) {
+			rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
+				fname);
+		}
+		kept = 1;
+		do_unlink(fname);
+	}
+
+	if (!kept && S_ISDIR(file->mode)) {
+		/* make an empty directory */
+		if (do_mkdir(buf, file->mode) < 0
+		    && (errno != ENOENT || make_bak_dir(buf) < 0
+		     || do_mkdir(buf, file->mode) < 0)) {
+			rsyserr(FINFO, errno, "mkdir %s failed",
+				full_fname(buf));
+		}
+
+		ret_code = do_rmdir(fname);
+		if (verbose > 2) {
+			rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
+				full_fname(fname), ret_code);
+		}
+		kept = 1;
+	}
+
+#ifdef SUPPORT_LINKS
+	if (!kept && preserve_links && S_ISLNK(file->mode)) {
+		const char *sl = F_SYMLINK(file);
+		if (safe_symlinks && unsafe_symlink(sl, buf)) {
+			if (verbose) {
+				rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
+					full_fname(buf), sl);
+			}
+			kept = 1;
+		} else {
+			do_unlink(buf);
+			if (do_symlink(sl, buf) < 0
+			    && (errno != ENOENT || make_bak_dir(buf) < 0
+			     || do_symlink(sl, buf) < 0)) {
+				rsyserr(FERROR, errno, "link %s -> \"%s\"",
+					full_fname(buf), sl);
+			}
+			do_unlink(fname);
+			kept = 1;
+		}
+	}
+#endif
+
+	if (!kept && !S_ISREG(file->mode)) {
+		rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
+			fname);
+		unmake_file(file);
+		return 1;
+	}
+
+	/* move to keep tree if a file */
+	if (!kept) {
+		if (robust_move(fname, buf) != 0) {
+			rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
+				full_fname(fname), buf);
+		} else if (sx.st.st_nlink > 1) {
+			/* If someone has hard-linked the file into the backup
+			 * dir, rename() might return success but do nothing! */
+			robust_unlink(fname); /* Just in case... */
+		}
+	}
+	set_file_attrs(buf, file, NULL, fname, 0);
+	unmake_file(file);
+
+	if (verbose > 1) {
+		rprintf(FINFO, "backed up %s to %s\n",
+			fname, buf);
 	}
 	return 1;
 }
+
+
+/* main backup switch routine */
+int make_backup(const char *fname)
+{
+	if (backup_dir)
+		return keep_backup(fname);
+	return make_simple_backup(fname);
+}