[rsync/rsync.git] / backup.c

/* 
   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 */

#include "rsync.h"

extern int verbose;
extern int backup_suffix_len;
extern int backup_dir_len;
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;

/* simple backup creates a backup with a suffix in the same directory */
static int make_simple_backup(char *fname)
{
	char fnamebak[MAXPATHLEN];
	if (strlen(fname) + backup_suffix_len > MAXPATHLEN-1) {
		rprintf(FERROR, "backup filename too long\n");
		return 0;
	}

	snprintf(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) {
			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;
}


/* 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)
{
	STRUCT_STAT st;
	STRUCT_STAT *st2;
	char fullpath[MAXPATHLEN];
	extern int orig_umask;
	char *p;
	char *q;

	while(strncmp(bak_path, "./", 2) == 0) bak_path += 2;

	if(bak_path[strlen(bak_path)-1] != '/') {
		snprintf(fullpath, sizeof(fullpath), "%s/", bak_path);
	} else {
		snprintf(fullpath, sizeof(fullpath), "%s", bak_path);
	}
	p = fullpath;
	q = &fullpath[strlen(fullpath)];  /* End of bak_path string */
	strcat(fullpath, fname);

	/* Make the directories */
	while ((p = strchr(p, '/'))) {
		*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));
					}
				}
			}
		}
		*p = '/';
		p++;
	}
	return 0;
}

/* 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);
			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) {
				/* external filesystem */
				case EXDEV:
					keep_path_extfs = 1;
					keep_trying--;
					break;
				/* no directory to write to */
				case ENOENT:
					make_dir(dst, 0700);
					keep_trying--;
					break;
				default:
					keep_trying = 0;
			} /* switch */
		} else
			keep_trying = 0;
	} /* while */
	return (!failed);
} /* robust_move */


/* 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;

	char keep_name [MAXPATHLEN];
	STRUCT_STAT st;
	struct file_struct *file;

	int kept = 0;
	int ret_code;

	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);
		initialised = 1;
	}

	/* 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;

	/* make a complete pathname for backup file */
	if (backup_dir_len+strlen(fname)+backup_suffix_len > MAXPATHLEN-1) {
		rprintf (FERROR, "keep_backup filename too long\n");
		return 0;
	}

	snprintf(keep_name, sizeof (keep_name), "%s/%s%s",
	    backup_dir, fname, backup_suffix);

#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->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);
			}
		}
		kept = 1;
		do_unlink(fname);
	}
#endif

	if(!kept && S_ISDIR(file->mode)) {
		/* make an empty directory */
		make_bak_dir(fname, backup_dir);
		do_mkdir(keep_name, file->mode);
		ret_code = do_rmdir(fname);

		if(verbose>2) {
			rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
				full_fname(fname), ret_code);
		}
		kept = 1;
	}

#if SUPPORT_LINKS
	if(!kept && preserve_links && S_ISLNK(file->mode)) {
		extern int safe_symlinks;
		if (safe_symlinks && unsafe_symlink(file->link, keep_name)) {
			if (verbose) {
				rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
					full_fname(keep_name), file->link);
			}
			kept = 1;
		}
		make_bak_dir(fname, backup_dir);
		if(do_symlink(file->link, keep_name) != 0) {
			rprintf(FERROR, "link %s -> %s : %s\n",
				full_fname(keep_name), file->link, strerror(errno));
		}
		do_unlink(fname);
		kept = 1;
	}
#endif
	if(!kept && preserve_hard_links && check_hard_link(file)) {
		if(verbose > 1)
			rprintf(FINFO, "%s is a hard link\n", f_name(file));
	}

	if(!kept && !S_ISREG(file->mode)) {
		rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
		    fname);
	}

	/* 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));
		}
	}
	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));
}
Commit	Line	Data
3d19b4c8 AT	1	/*
	2	Copyright (C) Andrew Tridgell 1999
	3
	4	This program is free software; you can redistribute it and/or modify
	5	it under the terms of the GNU General Public License as published by
	6	the Free Software Foundation; either version 2 of the License, or
	7	(at your option) any later version.
	8
	9	This program is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	GNU General Public License for more details.
	13
	14	You should have received a copy of the GNU General Public License
	15	along with this program; if not, write to the Free Software
	16	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	17	*/
	18
	19	/* backup handling code */
	20
	21	#include "rsync.h"
	22
	23	extern int verbose;
daa8ce83 WD	24	extern int backup_suffix_len;
daa8ce83 WD	25	extern int backup_dir_len;
3d19b4c8	26	extern char *backup_suffix;
66203a98	27	extern char *backup_dir;
3d19b4c8	28
378a074c AT	29	extern int am_root;
	30	extern int preserve_devices;
	31	extern int preserve_links;
	32	extern int preserve_hard_links;
	33
66203a98 AT	34	/* simple backup creates a backup with a suffix in the same directory */
66203a98 AT	35	static int make_simple_backup(char *fname)
3d19b4c8 AT	36	{
3d19b4c8 AT	37	char fnamebak[MAXPATHLEN];
daa8ce83	38	if (strlen(fname) + backup_suffix_len > MAXPATHLEN-1) {
47d6a60c	39	rprintf(FERROR, "backup filename too long\n");
3d19b4c8 AT	40	return 0;
	41	}
	42
47d6a60c S	43	snprintf(fnamebak, sizeof(fnamebak), "%s%s", fname, backup_suffix);
47d6a60c S	44	if (do_rename(fname, fnamebak) != 0) {
3d19b4c8 AT	45	/* cygwin (at least version b19) reports EINVAL */
3d19b4c8 AT	46	if (errno != ENOENT && errno != EINVAL) {
a039749b	47	rsyserr(FERROR, errno, "rename %s to backup %s", fname, fnamebak);
3d19b4c8 AT	48	return 0;
	49	}
	50	} else if (verbose > 1) {
47d6a60c	51	rprintf(FINFO, "backed up %s to %s\n", fname, fnamebak);
3d19b4c8 AT	52	}
	53	return 1;
	54	}
66203a98 AT	55
	56
	57	/* recursively make a directory path */
	58	static int make_dir(char *name, int mask)
	59	{
	60	char newdir [MAXPATHLEN];
	61	char p, d;
	62
	63	/* copy pathname over, look for last '/' */
	64	for (p = d = newdir; name; d++ = *name++)
	65	if (*name == '/')
	66	p = d;
	67	if (p == newdir)
	68	return 0;
	69	*p = 0;
	70
	71	/* make the new directory, if that fails then make its parent */
	72	while (do_mkdir (newdir, mask) != 0)
	73	if ((errno != ENOENT) \|\| !make_dir (newdir, mask))
	74	return 0;
	75
	76	return 1;
	77	} /* make_dir */
	78
	79
378a074c AT	80	/****************************************************************************
	81	Create a directory given an absolute path, perms based upon another directory
	82	path
	83	****************************************************************************/
47d6a60c	84	static int make_bak_dir(char fname, char bak_path)
378a074c	85	{
47d6a60c S	86	STRUCT_STAT st;
	87	STRUCT_STAT *st2;
	88	char fullpath[MAXPATHLEN];
	89	extern int orig_umask;
	90	char *p;
	91	char *q;
	92
	93	while(strncmp(bak_path, "./", 2) == 0) bak_path += 2;
	94
	95	if(bak_path[strlen(bak_path)-1] != '/') {
	96	snprintf(fullpath, sizeof(fullpath), "%s/", bak_path);
	97	} else {
	98	snprintf(fullpath, sizeof(fullpath), "%s", bak_path);
	99	}
	100	p = fullpath;
	101	q = &fullpath[strlen(fullpath)]; /* End of bak_path string */
	102	strcat(fullpath, fname);
	103
	104	/* Make the directories */
	105	while ((p = strchr(p, '/'))) {
	106	*p = 0;
	107	if(do_lstat(fullpath, &st) != 0) {
	108	do_mkdir(fullpath, 0777 & ~orig_umask);
	109	if(p>q) {
	110	if(do_lstat(q, &st) != 0) {
ea42541f WD	111	rprintf(FERROR, "make_bak_dir stat %s failed: %s\n",
ea42541f WD	112	full_fname(fullpath), strerror(errno));
47d6a60c S	113	} else {
	114	st2 = &st;
	115	set_modtime(fullpath, st2->st_mtime);
	116	if(do_lchown(fullpath, st2->st_uid, st2->st_gid) != 0) {
ea42541f WD	117	rprintf(FERROR, "make_bak_dir chown %s failed: %s\n",
ea42541f WD	118	full_fname(fullpath), strerror(errno));
47d6a60c S	119	}
47d6a60c S	120	if(do_chmod(fullpath, st2->st_mode) != 0) {
ea42541f WD	121	rprintf(FERROR, "make_bak_dir failed to set permissions on %s: %s\n",
ea42541f WD	122	full_fname(fullpath), strerror(errno));
47d6a60c S	123	}
	124	}
	125	}
	126	}
	127	*p = '/';
	128	p++;
	129	}
	130	return 0;
378a074c AT	131	}
378a074c AT	132
66203a98 AT	133	/* robustly move a file, creating new directory structures if necessary */
	134	static int robust_move(char src, char dst)
	135	{
	136	int keep_trying = 4;
	137	int keep_path_extfs = 0;
	138	int failed;
	139
	140	while (keep_trying) {
49d6fdc0 AT	141	if (keep_path_extfs) {
	142	failed = copy_file(src, dst, 0755);
	143	if (!failed) {
	144	do_unlink(src);
	145	}
	146	} else {
66203a98	147	failed = robust_rename (src, dst);
49d6fdc0	148	}
66203a98 AT	149
	150	if (failed) {
	151	if (verbose > 2)
	152	rprintf (FERROR, "robust_move failed: %s(%d)\n",
47d6a60c	153	strerror (errno), errno);
66203a98 AT	154	switch (errno) {
	155	/* external filesystem */
	156	case EXDEV:
	157	keep_path_extfs = 1;
	158	keep_trying--;
	159	break;
	160	/* no directory to write to */
	161	case ENOENT:
14820f63	162	make_dir(dst, 0700);
66203a98 AT	163	keep_trying--;
	164	break;
	165	default:
	166	keep_trying = 0;
	167	} /* switch */
	168	} else
	169	keep_trying = 0;
	170	} /* while */
	171	return (!failed);
	172	} /* robust_move */
	173
	174
	175	/* if we have a backup_dir, then we get here from make_backup().
	176	We will move the file to be deleted into a parallel directory tree */
	177	static int keep_backup(char *fname)
	178	{
378a074c	179
66203a98 AT	180	static int initialised;
	181
	182	char keep_name [MAXPATHLEN];
	183	STRUCT_STAT st;
	184	struct file_struct *file;
	185
47d6a60c	186	int kept = 0;
378a074c AT	187	int ret_code;
378a074c AT	188
66203a98	189	if (!initialised) {
daa8ce83 WD	190	if (backup_dir_len && backup_dir[backup_dir_len - 1] == '/')
daa8ce83 WD	191	backup_dir[--backup_dir_len] = '\0';
66203a98 AT	192	if (verbose > 0)
	193	rprintf (FINFO, "backup_dir is %s\n", backup_dir);
	194	initialised = 1;
	195	}
	196
	197	/* return if no file to keep */
	198	#if SUPPORT_LINKS
	199	if (do_lstat (fname, &st)) return 1;
	200	#else
	201	if (do_stat (fname, &st)) return 1;
	202	#endif
	203
af1d91c5	204	file = make_file(fname, NULL, NO_EXCLUDES);
f2cbf44b AT	205
	206	/* the file could have disappeared */
	207	if (!file) return 1;
66203a98	208
47d6a60c	209	/* make a complete pathname for backup file */
daa8ce83	210	if (backup_dir_len+strlen(fname)+backup_suffix_len > MAXPATHLEN-1) {
47d6a60c S	211	rprintf (FERROR, "keep_backup filename too long\n");
	212	return 0;
	213	}
378a074c	214
daa8ce83 WD	215	snprintf(keep_name, sizeof (keep_name), "%s/%s%s",
daa8ce83 WD	216	backup_dir, fname, backup_suffix);
378a074c AT	217
	218	#ifdef HAVE_MKNOD
	219	/* Check to see if this is a device file, or link */
47d6a60c S	220	if(IS_DEVICE(file->mode)) {
	221	if(am_root && preserve_devices) {
	222	make_bak_dir(fname, backup_dir);
	223	if(do_mknod(keep_name, file->mode, file->rdev) != 0) {
ea42541f WD	224	rprintf(FERROR, "mknod %s failed: %s\n",
ea42541f WD	225	full_fname(keep_name), strerror(errno));
47d6a60c	226	} else if(verbose>2) {
ea42541f	227	rprintf(FINFO, "make_backup: DEVICE %s successful.\n", fname);
47d6a60c S	228	}
	229	}
	230	kept = 1;
	231	do_unlink(fname);
	232	}
378a074c AT	233	#endif
	234
	235	if(!kept && S_ISDIR(file->mode)) {
	236	/* make an empty directory */
47d6a60c S	237	make_bak_dir(fname, backup_dir);
	238	do_mkdir(keep_name, file->mode);
	239	ret_code = do_rmdir(fname);
	240
	241	if(verbose>2) {
ea42541f WD	242	rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
ea42541f WD	243	full_fname(fname), ret_code);
47d6a60c S	244	}
	245	kept = 1;
	246	}
378a074c AT	247
378a074c AT	248	#if SUPPORT_LINKS
47d6a60c S	249	if(!kept && preserve_links && S_ISLNK(file->mode)) {
	250	extern int safe_symlinks;
	251	if (safe_symlinks && unsafe_symlink(file->link, keep_name)) {
	252	if (verbose) {
	253	rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
ea42541f	254	full_fname(keep_name), file->link);
47d6a60c S	255	}
	256	kept = 1;
	257	}
	258	make_bak_dir(fname, backup_dir);
	259	if(do_symlink(file->link, keep_name) != 0) {
	260	rprintf(FERROR, "link %s -> %s : %s\n",
ea42541f	261	full_fname(keep_name), file->link, strerror(errno));
47d6a60c S	262	}
	263	do_unlink(fname);
	264	kept = 1;
	265	}
378a074c	266	#endif
47d6a60c S	267	if(!kept && preserve_hard_links && check_hard_link(file)) {
	268	if(verbose > 1)
	269	rprintf(FINFO, "%s is a hard link\n", f_name(file));
	270	}
378a074c	271
47d6a60c S	272	if(!kept && !S_ISREG(file->mode)) {
	273	rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
	274	fname);
	275	}
66203a98	276
66203a98	277	/* move to keep tree if a file */
378a074c	278	if(!kept) {
47d6a60c	279	if (!robust_move (fname, keep_name)) {
ea42541f WD	280	rprintf(FERROR, "keep_backup failed: %s -> \"%s\": %s\n",
ea42541f WD	281	full_fname(fname), keep_name, strerror(errno));
47d6a60c S	282	}
47d6a60c S	283	}
66203a98 AT	284	set_perms (keep_name, file, NULL, 0);
	285	free_file (file);
	286	free (file);
378a074c	287
66203a98 AT	288	if (verbose > 1)
	289	rprintf (FINFO, "keep_backup %s -> %s\n", fname, keep_name);
	290	return 1;
	291	} /* keep_backup */
	292
	293
	294	/* main backup switch routine */
	295	int make_backup(char *fname)
	296	{
	297	if (backup_dir)
	298	return (keep_backup(fname));
	299	else
	300	return (make_simple_backup(fname));
	301	}