findmnt: support multiple --tab-file options

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

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index 6eb03749b32517f878d44feb3fa12f8d76fc3026..3990f63b96f30cb24b25580937b4b5d2b00651aa 100644 (file)
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -69,6 +69,12 @@ enum {
        FINDMNT_NCOLUMNS
 };
 
+enum {
+       TABTYPE_FSTAB = 1,
+       TABTYPE_MTAB,
+       TABTYPE_KERNEL
+};
+
 /* column names */
 struct colinfo {
        const char      *name;          /* header */
@@ -488,35 +494,61 @@ static int parser_errcb(struct libmnt_table *tb __attribute__ ((__unused__)),
        return 0;
 }
 
+static char **append_tabfile(char **files, int *nfiles, char *filename)
+{
+       void *tmp = realloc(files, sizeof(char *) * (*nfiles + 1));
+
+       if (!tmp) {
+               free(files);
+               return NULL;
+       }
+       files = tmp;
+       files[(*nfiles)++] = filename;
+       return files;
+}
+
 /* calls libmount fstab/mtab/mountinfo parser */
-static struct libmnt_table *parse_tabfile(const char *path, int force_path)
+static struct libmnt_table *parse_tabfiles(char **files,
+                                          int nfiles,
+                                          int tabtype)
 {
+       struct libmnt_table *tb;
        int rc;
-       struct libmnt_table *tb = mnt_new_table();
 
+       tb = mnt_new_table();
        if (!tb) {
                warn(_("failed to initialize libmount table"));
                return NULL;
        }
-
        mnt_table_set_parser_errcb(tb, parser_errcb);
 
-       /*
-        * 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 (!force_path && strcmp(path, _PATH_MOUNTED) == 0)
-               rc = mnt_table_parse_mtab(tb, NULL);
-       else
-               rc = mnt_table_parse_file(tb, path);
+       do {
+               /* NULL means that libmount will use default paths */
+               const char *path = nfiles ? *files++ : NULL;
+
+               switch (tabtype) {
+               case TABTYPE_FSTAB:
+                       rc = mnt_table_parse_fstab(tb, path);
+                       break;
+               case TABTYPE_MTAB:
+                       rc = mnt_table_parse_mtab(tb, path);
+                       break;
+               case TABTYPE_KERNEL:
+                       if (!path)
+                               path = access(_PATH_PROC_MOUNTINFO, R_OK) == 0 ?
+                                             _PATH_PROC_MOUNTINFO :
+                                             _PATH_PROC_MOUNTS;
+
+                       rc = mnt_table_parse_file(tb, path);
+                       break;
+               }
+               if (rc) {
+                       mnt_free_table(tb);
+                       warn(_("can't read %s"), path);
+                       return NULL;
+               }
+       } while (--nfiles > 0);
 
-       if (rc) {
-               mnt_free_table(tb);
-               warn(_("can't read %s"), path);
-               return NULL;
-       }
        return tb;
 }
 
@@ -847,11 +879,11 @@ errx_mutually_exclusive(const char *opts)
 
 int main(int argc, char *argv[])
 {
-       /* libmount */
        struct libmnt_table *tb = NULL;
-       char *tabfile = NULL, *alt_tabfile = NULL;
+       char **tabfiles = NULL;
        int direction = MNT_ITER_FORWARD;
        int i, c, rc = -1, timeout = -1;
+       int ntabfiles = 0, tabtype = 0;
 
        /* table.h */
        struct tt *tt = NULL;
@@ -927,7 +959,7 @@ int main(int argc, char *argv[])
                        flags |= FL_FIRSTONLY;
                        break;
                case 'F':
-                       alt_tabfile = optarg;
+                       tabfiles = append_tabfile(tabfiles, &ntabfiles, optarg);
                        break;
                case 'u':
                        disable_columns_truncate();
@@ -958,21 +990,21 @@ int main(int argc, char *argv[])
                        tt_flags &= ~TT_FL_TREE;
                        break;
                case 'm':               /* mtab */
-                       if (tabfile)
+                       if (tabtype)
                                errx_mutually_exclusive("--{fstab,mtab,kernel}");
-                       tabfile = _PATH_MOUNTED;
+                       tabtype = TABTYPE_MTAB;
                        tt_flags &= ~TT_FL_TREE;
                        break;
                case 's':               /* fstab */
-                       if (tabfile)
+                       if (tabtype)
                                errx_mutually_exclusive("--{fstab,mtab,kernel}");
-                       tabfile = _PATH_MNTTAB;
+                       tabtype = TABTYPE_FSTAB;
                        tt_flags &= ~TT_FL_TREE;
                        break;
                case 'k':               /* kernel (mountinfo) */
-                       if (tabfile)
+                       if (tabtype)
                                 errx_mutually_exclusive("--{fstab,mtab,kernel}");
-                       tabfile = _PATH_PROC_MOUNTINFO;
+                       tabtype = TABTYPE_KERNEL;
                        break;
                case 't':
                        set_match(COL_FSTYPE, optarg);
@@ -1025,16 +1057,15 @@ int main(int argc, char *argv[])
                columns[ncolumns++] = COL_OPTIONS;
        }
 
-       if (alt_tabfile)
-               tabfile = alt_tabfile;
+       if (!tabtype)
+               tabtype = TABTYPE_KERNEL;
 
-       if (!tabfile) {
-               tabfile = _PATH_PROC_MOUNTINFO;
 
-               if (access(tabfile, R_OK)) {            /* old kernel? */
-                       tabfile = _PATH_PROC_MOUNTS;
-                       tt_flags &= ~TT_FL_TREE;
-               }
+       if (flags & FL_POLL) {
+               if (tabtype != TABTYPE_KERNEL)
+                       errx_mutually_exclusive("--{poll,fstab,mtab}");
+               if (ntabfiles > 1)
+                       errx(EXIT_FAILURE, _("--poll accepts only one file, but mure specified by --tab-file"));
        }
 
        if (optind < argc && (get_match(COL_SOURCE) || get_match(COL_TARGET)))
@@ -1072,7 +1103,7 @@ int main(int argc, char *argv[])
         */
        mnt_init_debug(0);
 
-       tb = parse_tabfile(tabfile, alt_tabfile ? 1 : 0);
+       tb = parse_tabfiles(tabfiles, ntabfiles, tabtype);
        if (!tb)
                goto leave;
 
@@ -1118,8 +1149,8 @@ int main(int argc, char *argv[])
         * Fill in data to the output table
         */
        if (flags & FL_POLL)
-               /* poll mode */
-               rc = poll_table(tb, tabfile, timeout, tt, direction);
+               /* poll mode (accept the first tabfile only) */
+               rc = poll_table(tb, *tabfiles, timeout, tt, direction);
 
        else if ((tt_flags & TT_FL_TREE) && is_listall_mode())
                /* whole tree */
@@ -1138,6 +1169,7 @@ leave:
 
        mnt_free_table(tb);
        mnt_free_cache(cache);
+       free(tabfiles);
 
        return rc ? EXIT_FAILURE : EXIT_SUCCESS;
 }