o Move logic that determines size of the input image into its own

file. That logic has grown quite significantly now;

o add a special handling for the snapshot images. Those have some
  extra headers at the end of the image and we don't need those
  in the output image really.

MFC after:	6 weeks

usr.bin/mkuzip/Makefile

@@ -3,7 +3,7 @@
 PROG=	mkuzip
 MAN=	mkuzip.8
 SRCS=	mkuzip.c mkuz_blockcache.c mkuz_lzma.c mkuz_zlib.c mkuz_conveyor.c \
-	    mkuz_blk.c mkuz_fqueue.c mkuz_time.c
+	    mkuz_blk.c mkuz_fqueue.c mkuz_time.c mkuz_insize.c
 
 #CFLAGS+=	-DMKUZ_DEBUG
 

usr.bin/mkuzip/mkuz_cfg.h

@@ -36,5 +36,7 @@ struct mkuz_cfg {
     int en_dedup;
     int nworkers;
     int blksz;
+    const char *iname;
+    off_t isize;
     const struct mkuz_format *handler;
 };

usr.bin/mkuzip/mkuz_insize.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2004-2016 Maxim Sobolev <sobomax@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/disk.h>
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <err.h>
+#include <fcntl.h>
+
+#include "mkuz_cfg.h"
+#include "mkuz_insize.h"
+
+off_t
+mkuz_get_insize(struct mkuz_cfg *cfp)
+{
+	int ffd;
+	off_t ms;
+	struct stat sb;
+	struct statfs statfsbuf;
+
+	if (fstat(cfp->fdr, &sb) != 0) {
+		warn("fstat(%s)", cfp->iname);
+		return (-1);
+	}
+	if ((sb.st_flags & SF_SNAPSHOT) != 0) {
+		if (fstatfs(cfp->fdr, &statfsbuf) != 0) {
+			warn("fstatfs(%s)", cfp->iname);
+			return (-1);
+		}
+		ffd = open(statfsbuf.f_mntfromname, O_RDONLY);
+		if (ffd < 0) {
+			warn("open(%s, O_RDONLY)", statfsbuf.f_mntfromname);
+			return (-1);
+		}
+		if (ioctl(ffd, DIOCGMEDIASIZE, &ms) < 0) {
+			warn("ioctl(DIOCGMEDIASIZE)");
+			return (-1);
+		}
+		sb.st_size = ms;
+	} else if (S_ISCHR(sb.st_mode)) {
+		if (ioctl(cfp->fdr, DIOCGMEDIASIZE, &ms) < 0) {
+			warn("ioctl(DIOCGMEDIASIZE)");
+			return (-1);
+		}
+		sb.st_size = ms;
+	} else if (!S_ISREG(sb.st_mode)) {
+		warnx("%s: not a character device or regular file\n",
+			cfp->iname);
+		return (-1);
+	}
+	return (sb.st_size);
+}

usr.bin/mkuzip/mkuz_insize.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2016 Maxim Sobolev <sobomax@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+off_t mkuz_get_insize(struct mkuz_cfg *);

usr.bin/mkuzip/mkuzip.c

@@ -28,7 +28,6 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
-#include <sys/disk.h>
 #include <sys/endian.h>
 #include <sys/param.h>
 #include <sys/sysctl.h>
@@ -58,6 +57,7 @@ __FBSDID("$FreeBSD$");
 #include "mkuz_format.h"
 #include "mkuz_fqueue.h"
 #include "mkuz_time.h"
+#include "mkuz_insize.h"
 
 #define DEFAULT_CLSTSIZE	16384
 
@@ -94,7 +94,7 @@ cmp_blkno(const struct mkuz_blk *bp, void *p)
 int main(int argc, char **argv)
 {
 	struct mkuz_cfg cfs;
-	char *iname, *oname;
+	char *oname;
 	uint64_t *toc;
 	int i, io, opt, tmp;
 	struct {
@@ -102,7 +102,6 @@ int main(int argc, char **argv)
 		FILE *f;
 	} summary;
 	struct iovec iov[2];
-	struct stat sb;
 	uint64_t offset, last_offset;
 	struct cloop_header hdr;
 	struct mkuz_conveyor *cvp;
@@ -203,9 +202,9 @@ int main(int argc, char **argv)
 
 	c_ctx = cfs.handler->f_init(cfs.blksz);
 
-	iname = argv[0];
+	cfs.iname = argv[0];
 	if (oname == NULL) {
-		asprintf(&oname, "%s%s", iname, cfs.handler->default_sufx);
+		asprintf(&oname, "%s%s", cfs.iname, cfs.handler->default_sufx);
 		if (oname == NULL) {
 			err(1, "can't allocate memory");
 			/* Not reached */
@@ -219,30 +218,18 @@ int main(int argc, char **argv)
 	signal(SIGXFSZ, exit);
 	atexit(cleanup);
 
-	cfs.fdr = open(iname, O_RDONLY);
+	cfs.fdr = open(cfs.iname, O_RDONLY);
 	if (cfs.fdr < 0) {
-		err(1, "open(%s)", iname);
+		err(1, "open(%s)", cfs.iname);
 		/* Not reached */
 	}
-	if (fstat(cfs.fdr, &sb) != 0) {
-		err(1, "fstat(%s)", iname);
+	cfs.isize = mkuz_get_insize(&cfs);
+	if (cfs.isize < 0) {
+		errx(1, "can't determine input image size");
 		/* Not reached */
 	}
-	if (S_ISCHR(sb.st_mode)) {
-		off_t ms;
-
-		if (ioctl(cfs.fdr, DIOCGMEDIASIZE, &ms) < 0) {
-			err(1, "ioctl(DIOCGMEDIASIZE)");
-			/* Not reached */
-		}
-		sb.st_size = ms;
-	} else if (!S_ISREG(sb.st_mode)) {
-		fprintf(stderr, "%s: not a character device or regular file\n",
-			iname);
-		exit(1);
-	}
-	hdr.nblocks = sb.st_size / cfs.blksz;
-	if ((sb.st_size % cfs.blksz) != 0) {
+	hdr.nblocks = cfs.isize / cfs.blksz;
+	if ((cfs.isize % cfs.blksz) != 0) {
 		if (cfs.verbose != 0)
 			fprintf(stderr, "file size is not multiple "
 			"of %d, padding data\n", cfs.blksz);
@@ -270,7 +257,7 @@ int main(int argc, char **argv)
 
 	if (cfs.verbose != 0) {
 		fprintf(stderr, "data size %ju bytes, number of clusters "
-		    "%u, index length %zu bytes\n", sb.st_size,
+		    "%u, index length %zu bytes\n", cfs.isize,
 		    hdr.nblocks, iov[1].iov_len);
 	}
 
@@ -353,9 +340,9 @@ int main(int argc, char **argv)
 		et = getdtime();
 		fprintf(summary.f, "compressed data to %ju bytes, saved %lld "
 		    "bytes, %.2f%% decrease, %.2f bytes/sec.\n", offset,
-		    (long long)(sb.st_size - offset),
-		    100.0 * (long long)(sb.st_size - offset) /
-		    (float)sb.st_size, (float)sb.st_size / (et - st));
+		    (long long)(cfs.isize - offset),
+		    100.0 * (long long)(cfs.isize - offset) /
+		    (float)cfs.isize, (float)cfs.isize / (et - st));
 	}
 
 	/* Convert to big endian */