erase_mtab: do not limit ourself to 40 mtab entries

1 files changed, 21 insertions, 32 deletions

diff --git a/libbb/mtab.c b/libbb/mtab.c
index cce1aac5c..18386efb5 100644
--- a/libbb/mtab.c
+++ b/libbb/mtab.c
@@ -7,53 +7,42 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdlib.h>
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
-#include <stdio.h>
 #include <mntent.h>
 #include "libbb.h"
 
-#define MTAB_MAX_ENTRIES 40
-
-#ifdef CONFIG_FEATURE_MTAB_SUPPORT
+#if ENABLE_FEATURE_MTAB_SUPPORT
 void erase_mtab(const char *name)
 {
-        struct mntent entries[MTAB_MAX_ENTRIES];
-        int count = 0;
-        FILE *mountTable = setmntent(bb_path_mtab_file, "r");
+        struct mntent *entries = NULL;
+        int i, count = 0;
+        FILE *mountTable;
         struct mntent *m;
 
-        /* Check if reading the mtab file failed */
-        if (mountTable == 0
-                        /* Bummer.  fall back on trying the /proc filesystem */
-                        && (mountTable = setmntent("/proc/mounts", "r")) == 0) {
+        mountTable = setmntent(bb_path_mtab_file, "r");
+        /* Bummer. Fall back on trying the /proc filesystem */
+        if (!mountTable) mountTable = setmntent("/proc/mounts", "r");
+        if (!mountTable) {
                 bb_perror_msg(bb_path_mtab_file);
                 return;
         }
 
-        while (((m = getmntent(mountTable)) != 0) && (count < MTAB_MAX_ENTRIES))
-        {
-                entries[count].mnt_fsname = strdup(m->mnt_fsname);
-                entries[count].mnt_dir = strdup(m->mnt_dir);
-                entries[count].mnt_type = strdup(m->mnt_type);
-                entries[count].mnt_opts = strdup(m->mnt_opts);
-                entries[count].mnt_freq = m->mnt_freq;
-                entries[count].mnt_passno = m->mnt_passno;
-                count++;
+        while ((m = getmntent(mountTable)) != 0) {
+                i = count++;
+                entries = xrealloc(entries, count * sizeof(entries[0]));
+                entries[i].mnt_fsname = xstrdup(m->mnt_fsname);
+                entries[i].mnt_dir = xstrdup(m->mnt_dir);
+                entries[i].mnt_type = xstrdup(m->mnt_type);
+                entries[i].mnt_opts = xstrdup(m->mnt_opts);
+                entries[i].mnt_freq = m->mnt_freq;
+                entries[i].mnt_passno = m->mnt_passno;
         }
         endmntent(mountTable);
-        if ((mountTable = setmntent(bb_path_mtab_file, "w"))) {
-                int i;
 
+        mountTable = setmntent(bb_path_mtab_file, "w");
+        if (mountTable) {
                 for (i = 0; i < count; i++) {
-                        int result = (strcmp(entries[i].mnt_fsname, name) == 0
-                                                  || strcmp(entries[i].mnt_dir, name) == 0);
-
-                        if (result)
-                                continue;
-                        else
+                        if (strcmp(entries[i].mnt_fsname, name) != 0
+                         && strcmp(entries[i].mnt_dir, name) != 0)
                                 addmntent(mountTable, &entries[i]);
                 }
                 endmntent(mountTable);