fdisk: properly convert byte units K,M,G and T to cylinders/sectors

the shared command language assumed 512 byte sectors, which is
not the case for fdisk as it uses cylinders for the block unit.
so we introduce an extra argument in the Edit structure and
parseexpr() function so byte sizes are properly converted to
the block unit when the K,M,G and T postfixes are used.

6 files changed, 14 insertions, 9 deletions

diff --git a/sys/src/cmd/disk/prep/calc.y b/sys/src/cmd/disk/prep/calc.y
index 0829f09df..4cb81780e 100644
--- a/sys/src/cmd/disk/prep/calc.y
+++ b/sys/src/cmd/disk/prep/calc.y
@@ -79,7 +79,7 @@ mkOP(int ty, Exp *e1, Exp *e2)
 
 static char *inp;
 static jmp_buf jmp;
-static vlong dot, size, dollar;
+static vlong dot, size, dollar, unit;
 static char** errp;
 
 static int
@@ -110,7 +110,8 @@ yylex(void)
 			n *= 1024;
 			/* fall through */
 		case 'k':
-			n *= 2;
+			n *= 1024;
+			n /= unit;		/* convert to sectors */
 			break;
 		default:
 			--inp;
@@ -164,7 +165,7 @@ eval(Exp *e)
 int yyparse(void);
 
 char*
-parseexpr(char *s, vlong xdot, vlong xdollar, vlong xsize, vlong *result)
+parseexpr(char *s, vlong xdot, vlong xdollar, vlong xsize, vlong xunit, vlong *result)
 {
 	char *err;
 
@@ -176,6 +177,7 @@ parseexpr(char *s, vlong xdot, vlong xdollar, vlong xsize, vlong *result)
 	dot = xdot;
 	size = xsize;
 	dollar = xdollar;
+	unit = xunit;
 	yyparse();
 	if(yyexp == nil)
 		return "nil yylval?";
diff --git a/sys/src/cmd/disk/prep/edisk.c b/sys/src/cmd/disk/prep/edisk.c
index 907e1f53f..eb7645914 100644
--- a/sys/src/cmd/disk/prep/edisk.c
+++ b/sys/src/cmd/disk/prep/edisk.c
@@ -294,6 +294,7 @@ main(int argc, char **argv)
 		edit.disk->secsize = secsize;
 		edit.disk->secs = edit.disk->size / secsize;
 	}
+	edit.unitsz = edit.disk->secsize;
 	edit.end = edit.disk->secs;
 
 	if(blank)
diff --git a/sys/src/cmd/disk/prep/edit.c b/sys/src/cmd/disk/prep/edit.c
index 8a96116fa..6bca3ab1b 100644
--- a/sys/src/cmd/disk/prep/edit.c
+++ b/sys/src/cmd/disk/prep/edit.c
@@ -129,7 +129,7 @@ editdot(Edit *edit, int argc, char **argv)
 	if(argc > 2)
 		return "args";
 
-	if(err = parseexpr(argv[1], edit->dot, edit->end, edit->end, &ndot))
+	if(err = parseexpr(argv[1], edit->dot, edit->end, edit->end, edit->unitsz, &ndot))
 		return err;
 
 	edit->dot = ndot;
@@ -157,7 +157,7 @@ editadd(Edit *edit, int argc, char **argv)
 		fprint(2, "start %s: ", edit->unit);
 		q = getline(edit);
 	}
-	if(err = parseexpr(q, edit->dot, edit->end, edit->end, &start))
+	if(err = parseexpr(q, edit->dot, edit->end, edit->end, edit->unitsz, &start))
 		return err;
 
 	if(start < 0 || start >= edit->end)
@@ -181,7 +181,7 @@ editadd(Edit *edit, int argc, char **argv)
 		fprint(2, "end [%lld..%lld] ", start, maxend);
 		q = getline(edit);
 	}
-	if(err = parseexpr(q, edit->dot, maxend, edit->end, &end))
+	if(err = parseexpr(q, edit->dot, maxend, edit->end, edit->unitsz, &end))
 		return err;
 
 	if(start == end)
diff --git a/sys/src/cmd/disk/prep/edit.h b/sys/src/cmd/disk/prep/edit.h
index 8751adc4f..29ef4e993 100644
--- a/sys/src/cmd/disk/prep/edit.h
+++ b/sys/src/cmd/disk/prep/edit.h
@@ -36,6 +36,7 @@ struct Edit {
 	void *aux;
 	vlong dot;
 	vlong end;
+	vlong unitsz;
 
 	/* do not use fields below this line */
 	int changed;
@@ -48,7 +49,7 @@ void	runcmd(Edit*, char*);
 Part	*findpart(Edit*, char*);
 char	*addpart(Edit*, Part*);
 char	*delpart(Edit*, Part*);
-char *parseexpr(char *s, vlong xdot, vlong xdollar, vlong xsize, vlong *result);
+char *parseexpr(char *s, vlong xdot, vlong xdollar, vlong xsize, vlong xunit, vlong *result);
 int	ctldiff(Edit *edit, int ctlfd);
 void *emalloc(ulong);
 char *estrdup(char*);
diff --git a/sys/src/cmd/disk/prep/fdisk.c b/sys/src/cmd/disk/prep/fdisk.c
index c06b6fffc..073034942 100644
--- a/sys/src/cmd/disk/prep/fdisk.c
+++ b/sys/src/cmd/disk/prep/fdisk.c
@@ -141,8 +141,8 @@ main(int argc, char **argv)
 		edit.disk->secsize = secsize;
 		edit.disk->secs = edit.disk->size / secsize;
 	}
-
 	sec2cyl = edit.disk->h * edit.disk->s;
+	edit.unitsz = sec2cyl * edit.disk->secsize;
 	edit.end = edit.disk->secs / sec2cyl;
 
 	findmbr(&edit);
@@ -164,7 +164,7 @@ main(int argc, char **argv)
 	if(dowrite || printflag)
 		exits(0);
 
-	fprint(2, "cylinder = %lld bytes\n", sec2cyl*edit.disk->secsize);
+	fprint(2, "%s = %lld bytes\n", edit.unit, edit.unitsz);
 	runcmd(&edit, "p");
 	for(;;) {
 		fprint(2, ">>> ");
diff --git a/sys/src/cmd/disk/prep/prep.c b/sys/src/cmd/disk/prep/prep.c
index 20ad62a1d..8bd60c021 100644
--- a/sys/src/cmd/disk/prep/prep.c
+++ b/sys/src/cmd/disk/prep/prep.c
@@ -160,6 +160,7 @@ main(int argc, char **argv)
 		disk->secsize = secsize;
 		disk->secs = disk->size / secsize;
 	}
+	edit.unitsz = disk->secsize;
 	edit.end = disk->secs;
 
 	checkfat(disk);