Dump-like file system backup for Unix, built on Venti.

src/cmd/vbackup/vcat.c

@@ -0,0 +1,76 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include <diskfs.h>
+#include <thread.h>
+
+void
+usage(void)
+{
+	fprint(2, "usage: vcat [-z] score >diskfile\n");
+	threadexitsall("usage");
+}
+
+void
+threadmain(int argc, char **argv)
+{
+	extern int nfilereads;
+	char *pref;
+	int zerotoo;
+	uchar score[VtScoreSize];
+	u8int *zero;
+	u32int i;
+	u32int n;
+	Block *b;
+	Disk *disk;
+	Fsys *fsys;
+	VtCache *c;
+	VtConn *z;
+
+	zerotoo = 0;
+	ARGBEGIN{
+	case 'z':
+		zerotoo = 1;
+		break;
+	default:
+		usage();
+	}ARGEND
+
+	if(argc != 1)
+		usage();
+
+	fmtinstall('V', vtscorefmt);
+
+	if(vtparsescore(argv[0], &pref, score) < 0)
+		sysfatal("bad score '%s'", argv[0]);
+	if((z = vtdial(nil)) == nil)
+		sysfatal("vtdial: %r");
+	if(vtconnect(z) < 0)
+		sysfatal("vtconnect: %r");
+	if((c = vtcachealloc(z, 16384, 32, VtOREAD)) == nil)
+		sysfatal("vtcache: %r");
+	if((disk = diskopenventi(c, score)) == nil)
+		sysfatal("diskopenventi: %r");
+	if((fsys = fsysopen(disk)) == nil)
+		sysfatal("ffsopen: %r");
+
+	zero = emalloc(fsys->blocksize);
+	fprint(2, "%d blocks total\n", fsys->nblock);
+	n = 0;
+	for(i=0; i<fsys->nblock; i++){
+		if((b = fsysreadblock(fsys, i)) != nil){
+			if(pwrite(1, b->data, fsys->blocksize,
+			    (u64int)fsys->blocksize*i) != fsys->blocksize)
+				fprint(2, "error writing block %lud: %r\n", i);
+			n++;
+			blockput(b);
+		}else if(zerotoo)
+			if(pwrite(1, zero, fsys->blocksize,
+			    (u64int)fsys->blocksize*i) != fsys->blocksize)
+				fprint(2, "error writing block %lud: %r\n", i);
+		if(b == nil && i < 2)
+			sysfatal("block %d not in use", i);
+	}
+	fprint(2, "%d blocks in use, %d file reads\n", n, nfilereads);
+	threadexitsall(nil);
+}