findmnt: revert --fstab behavior, add --tab-file option

The optional argument for -s, --fstab options (--fstab=file) is not
backwardly compatible, because command line with short options (e.g.
findmnt -snr) will be interpreted incorrectly.

This patch removes support for the optional --fstab argument and
introduces a new option --tab-file, for example:

	findmnt --fstab --tab-file=/etc/fstab.foo

Reported-by: Juergen Daubert <jue@jue.li>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/findmnt.8 b/misc-utils/findmnt.8
index 7f3dc6ceed1a8f8432df93ff9bc5c522a8075506..cd2c47c8cb0551f3799765d5f1c02fd37bbbc653 100644 (file)
--- a/misc-utils/findmnt.8
+++ b/misc-utils/findmnt.8
@@ -36,14 +36,12 @@ The command prints all mounted filesystems in the tree-like format by default.
 .SH OPTIONS
 .IP "\fB\-h, \-\-help\fP"
 Print help and exit.
-.IP "\fB\-s, \-\-fstab\fR[\fI=fstab\fR]\fP"
+.IP "\fB\-s, \-\-fstab\fP"
 Search in
 .IR /etc/fstab
 and
 .IR /etc/fstab.d .
-The output is in the list format (see --list). Optionally, search the file
-specified by
-.IR fstab .
+The output is in the list format (see --list).
 .IP "\fB\-m, \-\-mtab\fP"
 Search in
 .IR /etc/mtab .
@@ -61,7 +59,10 @@ or
 .IR backward .
 .IP "\fB\-e, \-\-evaluate\fP"
 Convert all tags (LABEL or UUID) to the device names.
-.IP "\fB\-f, \-\-first-only\fP"
+.IP "\fB\-F, \-\-tab\-file \fIpath\fP"
+Search in an alternative file, if used with \fB\-\-fstab\fP, \fB\-\-mtab\fP
+or \fB\-\-kernel\fP then overwrites the default paths.
+.IP "\fB\-f, \-\-first\-only\fP"
 Print the first matching filesystem only.
 .IP "\fB\-i, \-\-invert\fP"
 Invert the sense of matching.

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index 5502a87808c6762d9cb6517bc960480b835dae4f..6eb03749b32517f878d44feb3fa12f8d76fc3026 100644 (file)
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -489,7 +489,7 @@ static int parser_errcb(struct libmnt_table *tb __attribute__ ((__unused__)),
 }
 
 /* calls libmount fstab/mtab/mountinfo parser */
-static struct libmnt_table *parse_tabfile(const char *path)
+static struct libmnt_table *parse_tabfile(const char *path, int force_path)
 {
        int rc;
        struct libmnt_table *tb = mnt_new_table();
@@ -501,9 +501,13 @@ static struct libmnt_table *parse_tabfile(const char *path)
 
        mnt_table_set_parser_errcb(tb, parser_errcb);
 
-       if (!strcmp(path, _PATH_MNTTAB))
+       /*
+        * If force_path is not set then use library defaults for mtab and
+        * fstab (the library is able to follow env.variables).
+        */
+       if (!force_path && strcmp(path, _PATH_MNTTAB) == 0)
                rc = mnt_table_parse_fstab(tb, NULL);
-       else if (!strcmp(path, _PATH_MOUNTED))
+       else if (!force_path && strcmp(path, _PATH_MOUNTED) == 0)
                rc = mnt_table_parse_mtab(tb, NULL);
        else
                rc = mnt_table_parse_file(tb, path);
@@ -516,6 +520,24 @@ static struct libmnt_table *parse_tabfile(const char *path)
        return tb;
 }
 
+/* checks if @tb contains parent->child relations */
+static int tab_is_tree(struct libmnt_table *tb)
+{
+       struct libmnt_fs *fs = NULL;
+       struct libmnt_iter *itr = NULL;
+       int rc = 0;
+
+       itr = mnt_new_iter(MNT_ITER_BACKWARD);
+       if (!itr)
+               return 0;
+
+       if (mnt_table_next_fs(tb, itr, &fs) == 0)
+               rc = mnt_fs_get_id(fs) > 0 && mnt_fs_get_parent_id(fs) > 0;
+
+       mnt_free_iter(itr);
+       return rc;
+}
+
 /* filter function for libmount (mnt_table_find_next_fs()) */
 static int match_func(struct libmnt_fs *fs,
                      void *data __attribute__ ((__unused__)))
@@ -770,7 +792,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 
        fprintf(out, _(
        "\nOptions:\n"
-       " -s, --fstab[=<fstab>]  search in static table of filesystems\n"
+       " -s, --fstab            search in static table of filesystems\n"
        " -m, --mtab             search in table of mounted filesystems\n"
        " -k, --kernel           search in kernel table of mounted\n"
         "                          filesystems (default)\n\n"));
@@ -784,6 +806,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
        " -c, --canonicalize     canonicalize printed paths\n"
        " -d, --direction <word> direction of search, 'forward' or 'backward'\n"
        " -e, --evaluate         convert tags (LABEL/UUID) to device names\n"
+       " -F, --tab-file <path>  alternative file for --fstab, --mtab or --kernel options\n"
        " -f, --first-only       print the first found filesystem only\n"));
 
        fprintf(out, _(
@@ -826,7 +849,7 @@ int main(int argc, char *argv[])
 {
        /* libmount */
        struct libmnt_table *tb = NULL;
-       char *tabfile = NULL;
+       char *tabfile = NULL, *alt_tabfile = NULL;
        int direction = MNT_ITER_FORWARD;
        int i, c, rc = -1, timeout = -1;
 
@@ -839,7 +862,7 @@ int main(int argc, char *argv[])
            { "direction",    1, 0, 'd' },
            { "evaluate",     0, 0, 'e' },
            { "first-only",   0, 0, 'f' },
-           { "fstab",        2, 0, 's' },
+           { "fstab",        0, 0, 's' },
            { "help",         0, 0, 'h' },
            { "invert",       0, 0, 'i' },
            { "kernel",       0, 0, 'k' },
@@ -856,6 +879,7 @@ int main(int argc, char *argv[])
            { "fsroot",       0, 0, 'v' },
            { "submounts",    0, 0, 'R' },
            { "source",       1, 0, 'S' },
+           { "tab-file",     1, 0, 'F' },
            { "target",       1, 0, 'T' },
            { "timeout",      1, 0, 'w' },
 
@@ -872,7 +896,7 @@ int main(int argc, char *argv[])
        tt_flags |= TT_FL_TREE;
 
        while ((c = getopt_long(argc, argv,
-                               "acd:ehifo:O:p::Pklmnrs::t:uvRS:T:w:",
+                               "acd:ehifF:o:O:p::Pklmnrst:uvRS:T:w:",
                                longopts, NULL)) != -1) {
                switch(c) {
                case 'a':
@@ -902,6 +926,9 @@ int main(int argc, char *argv[])
                case 'f':
                        flags |= FL_FIRSTONLY;
                        break;
+               case 'F':
+                       alt_tabfile = optarg;
+                       break;
                case 'u':
                        disable_columns_truncate();
                        break;
@@ -939,7 +966,7 @@ int main(int argc, char *argv[])
                case 's':               /* fstab */
                        if (tabfile)
                                errx_mutually_exclusive("--{fstab,mtab,kernel}");
-                       tabfile = optarg ? optarg : _PATH_MNTTAB;
+                       tabfile = _PATH_MNTTAB;
                        tt_flags &= ~TT_FL_TREE;
                        break;
                case 'k':               /* kernel (mountinfo) */
@@ -998,6 +1025,9 @@ int main(int argc, char *argv[])
                columns[ncolumns++] = COL_OPTIONS;
        }
 
+       if (alt_tabfile)
+               tabfile = alt_tabfile;
+
        if (!tabfile) {
                tabfile = _PATH_PROC_MOUNTINFO;
 
@@ -1042,10 +1072,13 @@ int main(int argc, char *argv[])
         */
        mnt_init_debug(0);
 
-       tb = parse_tabfile(tabfile);
+       tb = parse_tabfile(tabfile, alt_tabfile ? 1 : 0);
        if (!tb)
                goto leave;
 
+       if ((tt_flags & TT_FL_TREE) && !tab_is_tree(tb))
+               tt_flags &= ~TT_FL_TREE;
+
        cache = mnt_new_cache();
        if (!cache) {
                warn(_("failed to initialize libmount cache"));