wipefs: add -t <list> option

Signed-off-by: Karel Zak <kzak@redhat.com>

misc-utils/Makefile.am

@@ -68,7 +68,9 @@ blkid_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir)
 findfs_LDADD = $(ul_libblkid_la)
 findfs_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir)
 
-wipefs_SOURCES = wipefs.c $(top_srcdir)/lib/strutils.c
+wipefs_SOURCES = wipefs.c \
+		 $(top_srcdir)/lib/strutils.c \
+		 $(top_srcdir)/lib/match.c
 wipefs_LDADD = $(ul_libblkid_la)
 wipefs_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir)
 

misc-utils/wipefs.8

@@ -4,25 +4,40 @@
 .\"
 .TH WIPEFS 8 "October 2009" "util-linux" "System Administration"
 .SH NAME
-wipefs \- wipe a filesystem signature from a device
+wipefs \- wipe a signature from a device
 .SH SYNOPSIS
 .B wipefs
-.RB [ \-ahnpV ]
+.RB [ \-ahnptV ]
 .RB [ \-o
 .IR offset ]
 .I device
 .SH DESCRIPTION
 .B wipefs
-can erase filesystem or raid signatures (magic strings) from the specified
+can erase filesystem, raid or partition table signatures (magic strings) from
+the specified
 .I device
-to make the filesystem invisible for libblkid.
+to make the signature invisible for libblkid.
+
 .B wipefs
 does not erase the filesystem itself nor any other data from the device.
 When used without options \fB-a\fR or \fB-o\fR, it lists all visible filesystems
-and the offsets of their signatures.
+and the offsets of their basic signatures.
+
+Note that some filesystems or some partition tables store more magic strings on
+the devices. The
+.B wipefs
+lists the first offset where a magic string has been detected. The device is
+not scanned for additional magic strings for the same filesystem. It's possible
+that after \fBwipefs -o <offset>\fR will be the same filesystem or partition
+table visible by another magic string on another offset.
+
+When used with option \fB-a\fR then all for libblkid visible magic strings are
+erased.
+
 .SH OPTIONS
 .IP "\fB\-a, \-\-all\fP"
-Erase all available signatures.
+Erase all available signatures. This set of erased signatures could be
+restricted by \fB\-t <list>\fP option.
 .IP "\fB\-h, \-\-help\fP"
 Print help and exit.
 .IP "\fB\-n, \-\-no\-act\fP"
@@ -38,6 +53,11 @@ GiB, TiB, PiB and EiB (the "iB" is optional, e.g. "K" has the same meaning as
 .IP "\fB\-p, \-\-parsable\fP"
 Print out in parsable instead of printable format.  Encode all potentially unsafe
 characters of a string to the corresponding hex value prefixed by '\\x'.
+.IP "\fB\-t, \-\-types\fP \fIlist\fP
+Used to limit the set of printed or erased signatures. More than one type may
+be specified in a comma-separated list.  The list of types or individual types
+can be prefixed with 'no' to specify the types on which no action should be
+taken. For more details see mount(8).
 .IP "\fB\-V, \-\-version\fP"
 Output version information and exit.
 .SH AUTHOR

misc-utils/wipefs.c

@@ -36,6 +36,7 @@
 #include "xalloc.h"
 #include "strutils.h"
 #include "writeall.h"
+#include "match.h"
 #include "c.h"
 
 struct wipe_desc {
@@ -57,6 +58,8 @@ struct wipe_desc {
 #define WP_MODE_PRETTY		0		/* default */
 #define WP_MODE_PARSABLE	1
 
+static const char *type_pattern;
+
 static void
 print_pretty(struct wipe_desc *wp, int line)
 {
@@ -166,6 +169,9 @@ get_desc_for_probe(struct wipe_desc *wp, blkid_probe pr)
 	} else
 		return wp;
 
+	if (type_pattern && !match_fstype(type, type_pattern))
+		return wp;
+
 	offset = strtoll(off, NULL, 10);
 
 	wp = add_offset(wp, offset, 0);
@@ -336,6 +342,7 @@ usage(FILE *out)
 		" -n, --no-act        do everything except the actual write() call\n"
 		" -o, --offset <num>  offset to erase, in bytes\n"
 		" -p, --parsable      print out in parsable instead of printable format\n"
+		" -t, --types <list>  limit the set of filesystem, RAIDs or partition tables\n"
 		" -V, --version       output version information and exit\n"), out);
 
 	fprintf(out, _("\nFor more information see wipefs(8).\n"));
@@ -357,6 +364,7 @@ main(int argc, char **argv)
 	    { "no-act",    0, 0, 'n' },
 	    { "offset",    1, 0, 'o' },
 	    { "parsable",  0, 0, 'p' },
+	    { "types",     1, 0, 't' },
 	    { "version",   0, 0, 'V' },
 	    { NULL,        0, 0, 0 }
 	};
@@ -365,7 +373,7 @@ main(int argc, char **argv)
 	bindtextdomain(PACKAGE, LOCALEDIR);
 	textdomain(PACKAGE);
 
-	while ((c = getopt_long(argc, argv, "ahno:pV", longopts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "ahno:pt:V", longopts, NULL)) != -1) {
 		switch(c) {
 		case 'a':
 			all++;
@@ -383,6 +391,9 @@ main(int argc, char **argv)
 		case 'p':
 			mode = WP_MODE_PARSABLE;
 			break;
+		case 't':
+			type_pattern = optarg;
+			break;
 		case 'V':
 			printf(_("%s from %s\n"), program_invocation_short_name,
 				PACKAGE_STRING);