A few minor updates. ;-)

Seriously though, read the Changelog for busybox 0.42,
which this is about to become...
 -Erik

1 files changed, 142 insertions, 55 deletions

diff --git a/umount.c b/umount.c
index 68b27e3..b65caf7 100644
--- a/umount.c
+++ b/umount.c
@@ -37,11 +37,24 @@ static const char umount_usage[] =
 #else
 "\n"
 #endif
+#ifdef BB_FEATURE_REMOUNT
+"\t-r:\tTry to remount devices as read-only if mount is busy\n"
+#endif
 ;
 
+struct _mtab_entry_t {
+  char *device;
+  char *mountpt;
+  struct _mtab_entry_t *next;
+};
+
+static struct _mtab_entry_t *mtab_cache = NULL;
+
+
 
 static int useMtab = TRUE;
 static int umountAll = FALSE;
+static int doRemount = FALSE;
 extern const char mtab_file[]; /* Defined in utility.c */
 
 #define MIN(x,y) (x > y ? x : y)
@@ -50,21 +63,10 @@ static int
 do_umount(const char* name, int useMtab)
 {
     int status;
-    struct mntent *m;
-    FILE *mountTable;
-    const char *blockDevice = NULL;
-
-    if ((mountTable = setmntent (mtab_file, "r"))) {
-	while ((m = getmntent (mountTable)) != 0) {
-	    if (strncmp(m->mnt_dir, name,
-			MIN(strlen(m->mnt_dir),strlen(name))) == 0)
-		blockDevice = m->mnt_fsname;
-	    else if (strcmp(m->mnt_fsname, name) == 0) {
-		blockDevice = name;
-		name = m->mnt_dir;
-	    }
-	}
-    }
+    char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
+
+    if (blockDevice && strcmp(blockDevice, name) == 0)
+        name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT);
 
     status = umount(name);
 
@@ -73,57 +75,53 @@ do_umount(const char* name, int useMtab)
 	/* this was a loop device, delete it */
 	del_loop(blockDevice);
 #endif
-#if defined BB_MTAB
+#if defined BB_FEATURE_REMOUNT
+    if ( status != 0 && doRemount == TRUE && errno == EBUSY ) {
+        status = mount(blockDevice, name, NULL, 
+                       MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
+	if (status == 0) {
+	    fprintf(stderr, "umount: %s busy - remounted read-only\n", 
+                    blockDevice);
+	    /* TODO: update mtab if BB_MTAB is defined */
+	} else {
+	    fprintf(stderr, "umount: Cannot remount %s read-only\n",
+                    blockDevice);
+	}
+    }
+#endif
     if ( status == 0 ) {
+#if defined BB_MTAB
 	if ( useMtab==TRUE )
 	    erase_mtab(name);
-	return 0;
-    }
-    else
 #endif
-	return(status);
+	return( TRUE);
+    }
+    return(FALSE);
 }
 
 static int
 umount_all(int useMtab)
 {
-	int status;
-	struct mntent *m;
-        FILE *mountTable;
-
-        if ((mountTable = setmntent (mtab_file, "r"))) {
-            while ((m = getmntent (mountTable)) != 0) {
-                char *blockDevice = m->mnt_fsname;
-#if ! defined BB_MTAB
-		if (strcmp (blockDevice, "/dev/root") == 0) {
-		    struct fstab* fstabItem;
-		    fstabItem = getfsfile ("/");
-		    if (fstabItem != NULL) {
-			blockDevice = fstabItem->fs_spec;
-		    }
+	int status = TRUE;
+	char *mountpt;
+	void *iter;
+
+	for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
+            status=do_umount (mountpt, useMtab);
+            if (status != 0) {
+                /* Don't bother retrying the umount on busy devices */
+		if (errno == EBUSY) {
+                   perror(mountpt);
+		   continue;
 		}
-#endif
-		/* Don't umount /proc when doing umount -a */
-                if (strcmp (blockDevice, "proc") == 0)
-		    continue;
-
-		status=do_umount (m->mnt_dir, useMtab);
-		if (status!=0) {
-		    /* Don't bother retrying the umount on busy devices */
-		    if (errno==EBUSY) {
-			perror(m->mnt_dir); 
-			continue;
-		    }
-		    status=do_umount (blockDevice, useMtab);
-		    if (status!=0) {
-			printf ("Couldn't umount %s on %s (type %s): %s\n", 
-				blockDevice, m->mnt_dir, m->mnt_type, strerror(errno));
-		    }
+		status = do_umount (mountpt, useMtab);
+		if (status != 0) {
+                    printf ("Couldn't umount %s on %s: %s\n", 
+                        mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE), strerror(errno));
 		}
             }
-            endmntent (mountTable);
         }
-        return( TRUE);
+        return (status);
 }
 
 extern int
@@ -144,13 +142,18 @@ umount_main(int argc, char** argv)
 		useMtab = FALSE;
 		break;
 #endif
+#ifdef BB_FEATURE_REMOUNT
+	    case 'r':
+		doRemount = TRUE;
+		break;
+#endif
 	    default:
 		usage( umount_usage);
 	}
     }
 
-
-    if(umountAll==TRUE) {
+    mtab_read();
+    if (umountAll==TRUE) {
 	exit(umount_all(useMtab));
     }
     if ( do_umount(*argv,useMtab) == 0 )
@@ -161,3 +164,87 @@ umount_main(int argc, char** argv)
     }
 }
 
+
+
+/* These functions are here because the getmntent functions do not appear
+ * to be re-entrant, which leads to all sorts of problems when we try to
+ * use them recursively - randolph
+ */
+void mtab_read(void)
+{
+    struct _mtab_entry_t *entry = NULL;
+    struct mntent *e;
+    FILE *fp;
+  
+    if (mtab_cache != NULL) return;
+ 
+    if ((fp = setmntent(mtab_file, "r")) == NULL) {
+        fprintf(stderr, "Cannot open %s\n", mtab_file);
+	return;
+    }
+    while ((e = getmntent(fp))) {
+        entry = malloc(sizeof(struct _mtab_entry_t));
+	entry->device = strdup(e->mnt_fsname);
+	entry->mountpt = strdup(e->mnt_dir);
+	entry->next = mtab_cache;
+	mtab_cache = entry;
+    }
+    endmntent(fp);
+}
+
+char *mtab_getinfo(const char *match, const char which)
+{
+    struct _mtab_entry_t *cur = mtab_cache;
+    while (cur) {
+        if (strcmp(cur->mountpt, match) == 0 ||
+	    strcmp(cur->device, match) == 0) {
+	    if (which == MTAB_GETMOUNTPT) {
+	        return cur->mountpt;
+	    } else {
+#if !defined BB_MTAB
+                if (strcmp(cur->device, "/dev/root") == 0) {
+                    struct fstab* fstabItem;
+	            fstabItem = getfsfile ("/");
+	            if (fstabItem != NULL) return fstabItem->fs_spec;
+	        }
+#endif
+	        return cur->device;  
+	    }
+	}
+        cur = cur->next;
+    }
+    return NULL;
+}
+
+char *mtab_first(void **iter)
+{
+    struct _mtab_entry_t *mtab_iter;
+    if (!iter) return NULL;
+    mtab_iter = mtab_cache;
+    *iter = (void *)mtab_iter;
+    return mtab_next(iter);
+}
+
+char *mtab_next(void **iter)
+{
+    char *mp;
+    if (iter == NULL || *iter == NULL) return NULL;
+    mp = ((struct _mtab_entry_t *)(*iter))->mountpt;
+    *iter = (void *)((struct _mtab_entry_t *)(*iter))->next;
+    return mp;
+}
+
+void mtab_free(void)
+{
+    struct _mtab_entry_t *this, *next;
+
+    this = mtab_cache;
+    while (this) {
+      next = this->next;
+      if (this->device) free(this->device);
+      if (this->mountpt) free(this->mountpt);
+      free(this);
+      this = next;
+    }
+}
+