svn commit: r209614 - head/sbin/bsdlabel

[Jaakko Heinonen]

Author: jh
Date: Wed Jun 30 18:34:45 2010
New Revision: 209614
URL: http://svn.freebsd.org/changeset/base/209614

Log:
  - Don't assign the return value from read(2) to a variable of type
    int.
  - Use errx(3) instead of err(3) to print the error message on short
    reads in readlabel(). errno won't be set on short reads which can
    easily occur here due to the fixed size read request.
  
  PR:		144307
  Reviewed by:	bde

Modified:
  head/sbin/bsdlabel/bsdlabel.c

Modified: head/sbin/bsdlabel/bsdlabel.c
==============================================================================
--- head/sbin/bsdlabel/bsdlabel.c	Wed Jun 30 18:03:42 2010	(r209613)
+++ head/sbin/bsdlabel/bsdlabel.c	Wed Jun 30 18:34:45 2010	(r209614)
@@ -347,7 +347,7 @@ makelabel(const char *type, struct diskl
 static void
 readboot(void)
 {
-	int fd, i;
+	int fd;
 	struct stat st;
 	uint64_t *p;
 
@@ -358,8 +358,7 @@ readboot(void)
 		err(1, "cannot open %s", xxboot);
 	fstat(fd, &st);
 	if (alphacksum && st.st_size <= BBSIZE - 512) {
-		i = read(fd, bootarea + 512, st.st_size);
-		if (i != st.st_size)
+		if (read(fd, bootarea + 512, st.st_size) != st.st_size)
 			err(1, "read error %s", xxboot);
 
 		/*
@@ -372,8 +371,7 @@ readboot(void)
 		p[62] = 0;
 		return;
 	} else if ((!alphacksum) && st.st_size <= BBSIZE) {
-		i = read(fd, bootarea, st.st_size);
-		if (i != st.st_size)
+		if (read(fd, bootarea, st.st_size) != st.st_size)
 			err(1, "read error %s", xxboot);
 		return;
 	}
@@ -479,6 +477,7 @@ get_file_parms(int f)
 static int
 readlabel(int flag)
 {
+	ssize_t nbytes;
 	uint32_t lba;
 	int f, i;
 	int error;
@@ -498,8 +497,11 @@ readlabel(int flag)
 		errx(1,
 		    "disks with more than 2^32-1 sectors are not supported");
 	(void)lseek(f, (off_t)0, SEEK_SET);
-	if (read(f, bootarea, BBSIZE) != BBSIZE)
+	nbytes = read(f, bootarea, BBSIZE);
+	if (nbytes == -1)
 		err(4, "%s read", specname);
+	if (nbytes != BBSIZE)
+		errx(4, "couldn't read %d bytes from %s", BBSIZE, specname);
 	close (f);
 	error = bsd_disklabel_le_dec(
 	    bootarea + (labeloffset + labelsoffset * secsize),