findmnt: add --task <tid> option

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

diff --git a/misc-utils/findmnt.8 b/misc-utils/findmnt.8
index 69bae954f49d6c389eca67988553c633147da677..f92bffd317f155c4accd3ff32301130e28ad9a10 100644 (file)
--- a/misc-utils/findmnt.8
+++ b/misc-utils/findmnt.8
@@ -85,6 +85,12 @@ option and the option \fB\-\-submounts\fP is not used or if more that one
 source file (the option \fB\-F\fP) is specified.
 .IP "\fB\-v, \-\-nofsroot\fP"
 Do not print a [/dir] in the SOURCE column for bind-mounts or btrfs subvolumes.
+.IP "\fB\-N, \-\-task \fItid\fP"
+Use alternative namespace /proc/<tid>/mountinfo rather than the default
+/proc/self/mountinfo. If the option is specified more than once than tree-like
+output is disabled (see the \fB\-\-list\fP option). See also
+.BR unshare (1)
+command.
 .IP "\fB\-n, \-\-noheadings\fP"
 Do not print a header line.
 .IP "\fB\-u, \-\-notruncate\fP"

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index 75f7eb76175e7cd44b5634b5f6f3b8fcfbd01d21..1ef812cee0319baf4eeacd30f11062ed1035aa18 100644 (file)
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -629,6 +629,14 @@ static char **append_tabfile(char **files, int *nfiles, char *filename)
        return files;
 }
 
+static char **append_pid_tabfile(char **files, int *nfiles, pid_t pid)
+{
+       char *path = NULL;
+
+       xasprintf(&path, "/proc/%d/mountinfo", (int) pid);
+       return append_tabfile(files, nfiles, path);
+}
+
 /* calls libmount fstab/mtab/mountinfo parser */
 static struct libmnt_table *parse_tabfiles(char **files,
                                           int nfiles,
@@ -987,6 +995,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
        fprintf(out, _(
        " -i, --invert           invert the sense of matching\n"
        " -l, --list             use list format output\n"
+       " -N, --task <tid>       use alternative namespace (/proc/<tid>/mountinfo file)\n"
        " -n, --noheadings       don't print column headings\n"
        " -u, --notruncate       don't truncate text in columns\n"));
        fprintf(out, _(
@@ -1030,12 +1039,14 @@ int main(int argc, char *argv[])
                EXCL_FSTAB,
                EXCL_KERNEL,
                EXCL_MTAB,
+               EXCL_TASK,
 
                EXCL_RAW,
                EXCL_LIST,
                EXCL_PAIRS
        };
        int excl_fmk = EXCL_NONE;
+       int excl_fmN = EXCL_NONE;
        int excl_rlP = EXCL_NONE;
 
        /* table.h */
@@ -1067,6 +1078,7 @@ int main(int argc, char *argv[])
            { "submounts",    0, 0, 'R' },
            { "source",       1, 0, 'S' },
            { "tab-file",     1, 0, 'F' },
+           { "task",         1, 0, 'N' },
            { "target",       1, 0, 'T' },
            { "timeout",      1, 0, 'w' },
            { "version",      0, 0, 'V' },
@@ -1085,7 +1097,7 @@ int main(int argc, char *argv[])
        tt_flags |= TT_FL_TREE;
 
        while ((c = getopt_long(argc, argv,
-                               "AacDd:ehifF:o:O:p::Pklmnrst:uvRS:T:w:V",
+                               "AacDd:ehifF:o:O:p::PklmnN:rst:uvRS:T:w:V",
                                longopts, NULL)) != -1) {
                switch(c) {
                case 'A':
@@ -1156,11 +1168,13 @@ int main(int argc, char *argv[])
                        break;
                case 'm':               /* mtab */
                        exclusive_option(&excl_fmk, EXCL_MTAB, "--{fstab,mtab,kernel}");
+                       exclusive_option(&excl_fmN, EXCL_MTAB, "--{fstab,mtab,task}");
                        tabtype = TABTYPE_MTAB;
                        tt_flags &= ~TT_FL_TREE;
                        break;
                case 's':               /* fstab */
                        exclusive_option(&excl_fmk, EXCL_FSTAB, "--{fstab,mtab,kernel}");
+                       exclusive_option(&excl_fmN, EXCL_FSTAB, "--{fstab,mtab,task}");
                        tabtype = TABTYPE_FSTAB;
                        tt_flags &= ~TT_FL_TREE;
                        break;
@@ -1183,6 +1197,13 @@ int main(int argc, char *argv[])
                case 'n':
                        tt_flags |= TT_FL_NOHEADINGS;
                        break;
+               case 'N':
+                       exclusive_option(&excl_fmN, EXCL_KERNEL, "--{fstab,mtab,task}");
+                       tabtype = TABTYPE_KERNEL;
+                       tabfiles = append_pid_tabfile(tabfiles, &ntabfiles,
+                                       strtou32_or_err(optarg,
+                                               _("invalid TID argument")));
+                       break;
                case 'v':
                        flags |= FL_NOFSROOT;
                        break;