Fix block device-related issues in zdb.

Specifically, this fixes the two following errors in zdb when a pool
is composed of block devices:

1) 'Value too large for defined data type' when running 'zdb <dataset>'.
2) 'character device required' when running 'zdb -l <block-device>'.

Signed-off-by: Ricardo M. Correia <ricardo.correia@oracle.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

cmd/zdb/zdb.c

@@ -1803,7 +1803,7 @@ dump_label(const char *dev)
 		exit(1);
 	}
 
-	if (fstat64(fd, &statbuf) != 0) {
+	if (fstat64_blk(fd, &statbuf) != 0) {
 		(void) printf("failed to stat '%s': %s\n", path,
 		    strerror(errno));
 		free(path);
@@ -1811,14 +1811,6 @@ dump_label(const char *dev)
 		exit(1);
 	}
 
-	if (S_ISBLK(statbuf.st_mode)) {
-		(void) printf("cannot use '%s': character device required\n",
-		    path);
-		free(path);
-		(void) close(fd);
-		exit(1);
-	}
-
 	psize = statbuf.st_size;
 	psize = P2ALIGN(psize, (uint64_t)sizeof (vdev_label_t));
 

lib/libspl/include/sys/Makefile.am

@@ -36,6 +36,7 @@ libspl_HEADERS = \
 	$(top_srcdir)/lib/libspl/include/sys/processor.h \
 	$(top_srcdir)/lib/libspl/include/sys/sdt.h \
 	$(top_srcdir)/lib/libspl/include/sys/stack.h \
+	$(top_srcdir)/lib/libspl/include/sys/stat.h \
 	$(top_srcdir)/lib/libspl/include/sys/stropts.h \
 	$(top_srcdir)/lib/libspl/include/sys/sunddi.h \
 	$(top_srcdir)/lib/libspl/include/sys/sysevent.h \

lib/libspl/include/sys/Makefile.in

@@ -349,6 +349,7 @@ libspl_HEADERS = \
 	$(top_srcdir)/lib/libspl/include/sys/processor.h \
 	$(top_srcdir)/lib/libspl/include/sys/sdt.h \
 	$(top_srcdir)/lib/libspl/include/sys/stack.h \
+	$(top_srcdir)/lib/libspl/include/sys/stat.h \
 	$(top_srcdir)/lib/libspl/include/sys/stropts.h \
 	$(top_srcdir)/lib/libspl/include/sys/sunddi.h \
 	$(top_srcdir)/lib/libspl/include/sys/sysevent.h \

lib/libspl/include/sys/stat.h

@@ -0,0 +1,50 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#ifndef _LIBSPL_SYS_STAT_H
+#define _LIBSPL_SYS_STAT_H
+
+#include_next <sys/stat.h>
+
+#include <sys/mount.h> /* for BLKGETSIZE64 */
+
+/*
+ * Emulate Solaris' behavior of returning the block device size in fstat64().
+ */
+static inline int
+fstat64_blk(int fd, struct stat64 *st)
+{
+	if (fstat64(fd, st) == -1)
+		return -1;
+
+	/* In Linux we need to use an ioctl to get the size of a block device */
+	if (S_ISBLK(st->st_mode)) {
+		if (ioctl(fd, BLKGETSIZE64, &st->st_size) != 0)
+			return -1;
+	}
+
+	return 0;
+}
+#endif /* _LIBSPL_SYS_STAT_H */

lib/libzpool/kernel.c

@@ -36,7 +36,6 @@
 #include <sys/zfs_context.h>
 #include <sys/utsname.h>
 #include <sys/time.h>
-#include <sys/mount.h> /* for BLKGETSIZE64 */
 #include <sys/systeminfo.h>
 
 /*
@@ -592,22 +591,12 @@ vn_open(char *path, int x1, int flags, int mode, vnode_t **vpp, int x2, int x3)
 	if (fd == -1)
 		return (errno);
 
-	if (fstat64(fd, &st) == -1) {
+	if (fstat64_blk(fd, &st) == -1) {
 		err = errno;
 		close(fd);
 		return (err);
 	}
 
-#ifdef __linux__
-	/* In Linux, use an ioctl to get the size of a block device. */
-	if (S_ISBLK(st.st_mode)) {
-		if (ioctl(fd, BLKGETSIZE64, &st.st_size) != 0) {
-			err = errno;
-			close(fd);
-			return (err);
-		}
-	}
-#endif
 	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
 
 	*vpp = vp = umem_zalloc(sizeof (vnode_t), UMEM_NOFAIL);
@@ -699,10 +688,12 @@ int
 fop_getattr(vnode_t *vp, vattr_t *vap)
 {
 	struct stat64 st;
+	int err;
 
-	if (fstat64(vp->v_fd, &st) == -1) {
+	if (fstat64_blk(vp->v_fd, &st) == -1) {
+		err = errno;
 		close(vp->v_fd);
-		return (errno);
+		return (err);
 	}
 
 	vap->va_size = st.st_size;