[Dump-users] Brown paper bag bug (and fix) for 'restore -C' (0.4b38)

[Stelian P. <st...@po...>]

On Tue, Jan 11, 2005 at 03:21:13PM -0800, Kenneth Porter wrote:

> Tried a full backup with verify and I think -C is broken. I'm seeing this, 
> which looks like it's trying to restore the files instead of compare them:
> 
> abort? [yn] /usr/sbin/restore: cannot rename ./var/lib/mysql/mysql/db.MYI 
> to RSTTMP02: No such file or directory
> 
> I found my mysql directory clobbered. With what appeared to be the original 
> under another name, /var/lib/RSTTMP06373651. Fortunately I was able to 
> recover by renaming it into place.

Got it. In fact it was a bug in restore, when using the -C mode,
which was affecting directories containing a file with the same name
as the directory (such as /var/lib/mysql/mysql, or
/lib/modules/2.6.9-1.667/build/scripts/genksyms/genksyms)

The attached patch should solve the problem. The patch also forces
the -N option (do not write on the disk) of restore when doing a
comparision, this should in the future prevent other bugs like this
one.

Please test this patch (or the CVS version which contains it), I will
release 0.4b39 early next week.

Thanks Kenneth for all the help you gave on this bug.

Stelian.

Index: restore/symtab.c
===================================================================
RCS file: /cvsroot/dump/dump/restore/symtab.c,v
retrieving revision 1.23
diff -u -r1.23 symtab.c
--- restore/symtab.c	14 Dec 2004 14:07:58 -0000	1.23
+++ restore/symtab.c	14 Jan 2005 12:55:14 -0000
@@ -189,9 +189,16 @@
 	char *np, *cp;
 	char buf[MAXPATHLEN];
 
+	ep = lookupino(ROOTINO);
+
 	cp = name;
+	if (*cp == '.')
+		++cp;
+	if (*cp == '/')
+		++cp;
+	if (*cp == '\0')
+		return ep;
 
-	ep = lookupino(ROOTINO);
 	while (ep != NULL) {
 		for (np = buf; *cp != '/' && *cp != '\0' &&
 				np < &buf[sizeof(buf)]; )
@@ -202,8 +209,7 @@
 
 		oldep = ep;
 
-		if (strcmp(ep->e_name, buf) != 0 &&
-		    ep->e_entries != NULL) {
+		if (ep->e_entries != NULL) {
 
 			ep = ep->e_entries[dir_hash(buf)];
 			for ( ; ep != NULL; ep = ep->e_sibling)
Index: restore/main.c
===================================================================
RCS file: /cvsroot/dump/dump/restore/main.c,v
retrieving revision 1.48
diff -u -r1.48 main.c
--- restore/main.c	13 Jan 2005 15:41:06 -0000	1.48
+++ restore/main.c	14 Jan 2005 12:55:14 -0000
@@ -424,6 +424,7 @@
 		Vprintf(stdout, "Begin compare restore\n");
 		compare_ignore_not_found = 0;
 		compare_errors = 0;
+		Nflag = 1;
 		setup();
 		printf("filesys = %s\n", filesys);
 		if (STAT(filesys, &stbuf) < 0)
-- 
Stelian Pop <st...@po...>