X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/66203a982b3d249bafda9b9272c4c103c19e4a9b..cb197514d99d17dc3a1ce26ff8918d63307d75e4:/backup.c

diff --git a/backup.c b/backup.c
index 24f8523a..5805f16a 100644
--- a/backup.c
+++ b/backup.c
@@ -1,179 +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"
+#include "ifuncs.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;
+}
 
-/* simple backup creates a backup with a suffix in the same directory */
-static int make_simple_backup(char *fname)
+/****************************************************************************
+Create a directory given an absolute path, perms based upon another directory
+path
+****************************************************************************/
+int make_bak_dir(const char *fullpath)
 {
-	char fnamebak[MAXPATHLEN];
-	if (strlen(fname) + strlen(backup_suffix) > (MAXPATHLEN-1)) {
-		rprintf(FERROR,"backup filename too long\n");
-		return 0;
+	char fbuf[MAXPATHLEN], *rel, *end, *p;
+	struct file_struct *file;
+	int len = backup_dir_len;
+	stat_x sx;
+
+	while (*fullpath == '.' && fullpath[1] == '/') {
+		fullpath += 2;
+		len -= 2;
 	}
 
-	slprintf(fnamebak,sizeof(fnamebak),"%s%s",fname,backup_suffix);
-	if (do_rename(fname,fnamebak) != 0) {
-		/* 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 (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;
+			}
 		}
-	} else if (verbose > 1) {
-		rprintf(FINFO,"backed up %s to %s\n",fname,fnamebak);
 	}
-	return 1;
+
+	/* 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 += 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;
 }
 
+/* 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 (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;
+}
 
-/* recursively make a directory path */
-static int make_dir(char *name, int mask)
+/* 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)
 {
-	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)
+	stat_x sx;
+	struct file_struct *file;
+	int save_preserve_xattrs;
+	char *buf = get_backup_name(fname);
+	int ret = 0;
+
+	if (!buf)
 		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))
+	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 1;
-} /* make_dir */
+	/* Fall back to making a copy. */
+	if (!(file = make_file(fname, NULL, &sx.st, 0, NO_FILTERS)))
+		return 1; /* the file could have disappeared */
 
+#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
 
-/* robustly move a file, creating new directory structures if necessary */
-static int robust_move(char *src, char *dst)
-{
-	int keep_trying = 4;
-	int keep_path_extfs = 0;
-	int failed;
-
-	while (keep_trying) {
-		if (keep_path_extfs)
-			failed = copy_file (src, dst, 0755);
-		else
-			failed = robust_rename (src, dst);
-
-		if (failed) {
-			if (verbose > 2)
-				rprintf (FERROR, "robust_move failed: %s(%d)\n",
-					strerror (errno), errno);
-			switch (errno) {
-				/* external filesystem */
-				case EXDEV:
-					keep_path_extfs = 1;
-					keep_trying--;
-					break;
-				/* no directory to write to */
-				case ENOENT:
-					make_dir (dst, 0755);
-					keep_trying--;
-					break;
-				default:
-					keep_trying = 0;
-			} /* switch */
+	/* 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))) {
+		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
-			keep_trying = 0;
-	} /* while */
-	return (!failed);
-} /* robust_move */
+			save_errno = 0;
+		if (DEBUG_GTE(BACKUP, 1) && save_errno == 0) {
+			rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
+				fname);
+		}
+		ret = 2;
+	}
 
+	if (!ret && S_ISDIR(file->mode)) {
+		int ret_code;
+		/* make an empty directory */
+		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 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)
-{
-	static int initialised;
+		ret_code = do_rmdir(fname);
+		if (DEBUG_GTE(BACKUP, 1)) {
+			rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
+				full_fname(fname), ret_code);
+		}
+		ret = 2;
+	}
 
-	char keep_name [MAXPATHLEN];
-	STRUCT_STAT st;
-	struct file_struct *file;
+#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(buf), sl);
+			}
+			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;
+		}
+	}
+#endif
 
-	if (!initialised) {
-		if (backup_dir[strlen(backup_dir) - 1] == '/')
-			backup_dir[strlen(backup_dir) - 1] = 0;
-		if (verbose > 0)
-			rprintf (FINFO, "backup_dir is %s\n", backup_dir);
-		initialised = 1;
+	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;
 	}
 
-	/* return if no file to keep */
-#if SUPPORT_LINKS
-	if (do_lstat (fname, &st)) return 1;
-#else
-	if (do_stat (fname, &st)) return 1;
+	/* 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;
+	}
 
-	file = make_file (0, fname);
+	save_preserve_xattrs = preserve_xattrs;
+	preserve_xattrs = 0;
+	set_file_attrs(buf, file, NULL, fname, 0);
+	preserve_xattrs = save_preserve_xattrs;
 
-	/* make a complete pathname for backup file */
-	if (strlen(backup_dir) + strlen(fname) > (MAXPATHLEN - 1)) {
-		rprintf (FERROR, "keep_backup filename too long\n");
-		return 0;
-	}
-	slprintf(keep_name, sizeof (keep_name), "%s/%s", backup_dir, fname);
+	unmake_file(file);
+#ifdef SUPPORT_ACLS
+	uncache_tmp_acls();
+#endif
+#ifdef SUPPORT_XATTRS
+	uncache_tmp_xattrs();
+#endif
 
-	if (!S_ISDIR(file->mode)) {
-	/* move to keep tree if a file */
-		if (!robust_move (fname, keep_name))
-			rprintf(FERROR, "keep_backup failed %s -> %s : %s\n",
-				fname, keep_name, strerror(errno));
-	} else {
-	/* this bit only used to "keep" empty directories */
-		/* make the parent directories */
-		make_dir (keep_name, 0755);
-		/* now make the (empty) directory */
-		do_mkdir (keep_name, file->mode);
-		if (verbose > 1)
-			rprintf (FINFO, "keep_backup: made empty dir: %s\n",
-				keep_name);
-	}
-
-	set_perms (keep_name, file, NULL, 0);
-	free_file (file);
-	free (file);
-	if (verbose > 1)
-		rprintf (FINFO, "keep_backup %s -> %s\n", fname, keep_name);
-	return 1;
-} /* keep_backup */
-
-
-/* main backup switch routine */
-int make_backup(char *fname)
-{
-	if (backup_dir)
-		return (keep_backup(fname));
-	else
-		return (make_simple_backup(fname));
+  success:
+	if (INFO_GTE(BACKUP, 1)) {
+		rprintf(FINFO, "backed up %s to %s\n",
+			fname, buf);
+	}
+	return ret;
 }
-