svn commit: r285936 - stable/10/sbin/geom/class/part

[Andrey V. Elsukov]

Author: ae
Date: Tue Jul 28 08:22:50 2015
New Revision: 285936
URL: https://svnweb.freebsd.org/changeset/base/285936

Log:
  MFC r285735:
    lseek() allows an offset to be set beyond the end of file. Using
    it to check that partition has enough space to write bootcode doesn't
    work. Use the known size of provider instead.
  
    PR:		201504

Modified:
  stable/10/sbin/geom/class/part/geom_part.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sbin/geom/class/part/geom_part.c
==============================================================================
--- stable/10/sbin/geom/class/part/geom_part.c	Tue Jul 28 07:30:07 2015	(r285935)
+++ stable/10/sbin/geom/class/part/geom_part.c	Tue Jul 28 08:22:50 2015	(r285936)
@@ -1095,14 +1095,11 @@ gpart_write_partcode(struct ggeom *gp, i
 
 	if (pp != NULL) {
 		snprintf(dsf, sizeof(dsf), "/dev/%s", pp->lg_name);
+		if (pp->lg_mediasize < size)
+			errx(EXIT_FAILURE, "%s: not enough space", dsf);
 		fd = open(dsf, O_WRONLY);
 		if (fd == -1)
 			err(EXIT_FAILURE, "%s", dsf);
-		if (lseek(fd, size, SEEK_SET) != size)
-			errx(EXIT_FAILURE, "%s: not enough space", dsf);
-		if (lseek(fd, 0, SEEK_SET) != 0)
-			err(EXIT_FAILURE, "%s", dsf);
-
 		/*
 		 * When writing to a disk device, the write must be
 		 * sector aligned and not write to any partial sectors,
@@ -1141,11 +1138,11 @@ gpart_write_partcode_vtoc8(struct ggeom 
 		if (pp->lg_sectorsize != sizeof(struct vtoc8))
 			errx(EXIT_FAILURE, "%s: unexpected sector "
 			    "size (%d)\n", dsf, pp->lg_sectorsize);
+		if (pp->lg_mediasize < VTOC_BOOTSIZE)
+			continue;
 		fd = open(dsf, O_WRONLY);
 		if (fd == -1)
 			err(EXIT_FAILURE, "%s", dsf);
-		if (lseek(fd, VTOC_BOOTSIZE, SEEK_SET) != VTOC_BOOTSIZE)
-			continue;
 		/*
 		 * We ignore the first VTOC_BOOTSIZE bytes of boot code in
 		 * order to avoid overwriting the label.