findmnt: improve --df output

* don't print pseudo-filesystems (except tmpfs)
 * add --all to disable built-in filters
 * don't overwrite --df --output=<list> with default columns

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

misc-utils/findmnt.8

@@ -47,11 +47,17 @@ The output is in the list format (see --list).
 Search in
 .IR /proc/self/mountinfo .
 The output is in the tree-like format.  This is the default.
+
+.IP "\fB\-A, \-\-all\fP"
+Disable all built-in filters and print all filesystems.
+.IP "\fB\-a, \-\-ascii\fP"
+Use ascii characters for tree formatting.
 .IP "\fB\-c, \-\-canonicalize\fP"
 Canonicalize all printed paths.
 .IP "\fB\-D, \-\-df\fP"
 Imitate the output of df(1). This option is equivalent to
-"-o SOURCE,FSTYPE,SIZE,USED,AVAIL,USE%,TARGET".
+"-o SOURCE,FSTYPE,SIZE,USED,AVAIL,USE%,TARGET", but excludes all
+pseudo filesystem. Use \fB\-\-all\fP to print all filesystems.
 .IP "\fB\-d, \-\-direction \fIword\fP"
 The search direction -
 .IR forward
@@ -148,8 +154,6 @@ available for umount and remount actions
 Use key="value" output format.
 .IP "\fB\-r, \-\-raw\fP"
 Use raw output format.
-.IP "\fB\-a, \-\-ascii\fP"
-Use ascii characters for tree formatting.
 .IP "\fB\-t, \-\-types \fIlist\fP"
 Limit the set of printed filesystems.  More than one type may be
 specified in a comma-separated list.  The list of filesystem types can be

misc-utils/findmnt.c

@@ -51,7 +51,9 @@ enum {
 	FL_NOSWAPMATCH	= (1 << 6),
 	FL_NOFSROOT	= (1 << 7),
 	FL_SUBMOUNTS	= (1 << 8),
-	FL_POLL		= (1 << 9)
+	FL_POLL		= (1 << 9),
+	FL_DF		= (1 << 10),
+	FL_ALL		= (1 << 11)
 };
 
 /* column IDs */
@@ -192,6 +194,9 @@ static int is_tabdiff_column(int id)
  */
 static int is_listall_mode(void)
 {
+	if ((flags & FL_DF) && !(flags & FL_ALL))
+		return 0;
+
 	return (!get_match(COL_SOURCE) &&
 		!get_match(COL_TARGET) &&
 		!get_match(COL_FSTYPE) &&
@@ -638,6 +643,16 @@ static int match_func(struct libmnt_fs *fs,
 	if (m && !mnt_fs_match_options(fs, m))
 		return rc;
 
+	if ((flags & FL_DF) && !(flags & FL_ALL)) {
+		const char *type = mnt_fs_get_fstype(fs);
+
+		if (type && strstr(type, "tmpfs"))	/* tmpfs is wanted */
+			return !rc;
+
+		if (mnt_fs_is_pseudofs(fs))
+			return rc;
+	}
+
 	return !rc;
 }
 
@@ -881,6 +896,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 	" -w, --timeout <num>    upper limit in milliseconds that --poll will block\n\n"));
 
 	fprintf(out, _(
+	" -A, --all              disable all built-in filters, print all filesystems\n"
 	" -a, --ascii            use ASCII chars for tree formatting\n"
 	" -c, --canonicalize     canonicalize printed paths\n"
 	" -D, --df               imitate the output of df(1)\n"
@@ -930,13 +946,14 @@ int main(int argc, char *argv[])
 	struct libmnt_table *tb = NULL;
 	char **tabfiles = NULL;
 	int direction = MNT_ITER_FORWARD;
-	int i, c, rc = -1, timeout = -1, df_output = 0;
+	int i, c, rc = -1, timeout = -1;
 	int ntabfiles = 0, tabtype = 0;
 
 	/* table.h */
 	struct tt *tt = NULL;
 
 	static const struct option longopts[] = {
+	    { "all",          0, 0, 'A' },
 	    { "ascii",        0, 0, 'a' },
 	    { "canonicalize", 0, 0, 'c' },
 	    { "direction",    1, 0, 'd' },
@@ -977,9 +994,12 @@ int main(int argc, char *argv[])
 	tt_flags |= TT_FL_TREE;
 
 	while ((c = getopt_long(argc, argv,
-				"acDd:ehifF:o:O:p::Pklmnrst:uvRS:T:w:",
+				"AacDd:ehifF:o:O:p::Pklmnrst:uvRS:T:w:",
 				longopts, NULL)) != -1) {
 		switch(c) {
+		case 'A':
+			flags |= FL_ALL;
+			break;
 		case 'a':
 			tt_flags |= TT_FL_ASCII;
 			break;
@@ -988,7 +1008,7 @@ int main(int argc, char *argv[])
 			break;
 		case 'D':
 			tt_flags &= ~TT_FL_TREE;
-			df_output = 1;
+			flags |= FL_DF;
 			break;
 		case 'd':
 			if (!strcmp(optarg, "forward"))
@@ -1099,7 +1119,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (df_output) {
+	if (!ncolumns && (flags & FL_DF)) {
 		columns[ncolumns++] = COL_SOURCE;
 		columns[ncolumns++] = COL_FSTYPE;
 		columns[ncolumns++] = COL_SIZE;