rmmod: behavior more like m-i-t's rmmod

In line with m-i-t's behavior, we should check to see if each module is:

- loaded
- has any holders
- has a 0 refcnt

Detecting any of these lets us provide a more useful message than the
kernel's EPERM response to delete_module(2).

Additionally, alter the main loop behavior to avoid exiting early on the
first error.

diff --git a/tools/kmod-rmmod.c b/tools/kmod-rmmod.c
index 658ff6b0e69905db31b6d1ca3881b43ed427efe0..33a73ca324348d36d369ebd5fe00ec996cee82b1 100644 (file)
--- a/tools/kmod-rmmod.c
+++ b/tools/kmod-rmmod.c
@@ -100,6 +100,42 @@ static void log_syslog(void *data, int priority, const char *file, int line,
        (void)data;
 }
 
+static int check_module_inuse(struct kmod_module *mod) {
+       struct kmod_list *holders;
+
+       if (kmod_module_get_initstate(mod) == -ENOENT) {
+               fprintf(stderr, "Error: Module %s is not currently loaded\n",
+                               kmod_module_get_name(mod));
+               return -ENOENT;
+       }
+
+       holders = kmod_module_get_holders(mod);
+       if (holders != NULL) {
+               struct kmod_list *itr;
+
+               fprintf(stderr, "Error: Module %s is in use by:",
+                               kmod_module_get_name(mod));
+
+               kmod_list_foreach(itr, holders) {
+                       struct kmod_module *hm = kmod_module_get_module(itr);
+                       fprintf(stderr, " %s", kmod_module_get_name(hm));
+                       kmod_module_unref(hm);
+               }
+               fputc('\n', stderr);
+
+               kmod_module_unref_list(holders);
+               return -EBUSY;
+       }
+
+       if (kmod_module_get_refcnt(mod) != 0) {
+               fprintf(stderr, "Error: Module %s is in use\n",
+                               kmod_module_get_name(mod));
+               return -EBUSY;
+       }
+
+       return 0;
+}
+
 static int do_rmmod(int argc, char *argv[])
 {
        struct kmod_ctx *ctx;
@@ -107,7 +143,7 @@ static int do_rmmod(int argc, char *argv[])
        int flags = KMOD_REMOVE_NOWAIT;
        int use_syslog = 0;
        int verbose = 0;
-       int i, err = 0;
+       int i, err, r = 0;
 
        for (;;) {
                int c, idx = 0;
@@ -175,15 +211,21 @@ static int do_rmmod(int argc, char *argv[])
                        break;
                }
 
+               if (!(flags & KMOD_REMOVE_FORCE) && (flags & KMOD_REMOVE_NOWAIT))
+                       if (check_module_inuse(mod) < 0) {
+                               r++;
+                               goto next;
+                       }
+
                err = kmod_module_remove_module(mod, flags);
                if (err < 0) {
                        fprintf(stderr,
                                "Error: could not remove module %s: %s\n",
                                arg, strerror(-err));
+                       r++;
                }
+next:
                kmod_module_unref(mod);
-               if (err < 0)
-                       break;
        }
 
        kmod_unref(ctx);
@@ -191,7 +233,7 @@ static int do_rmmod(int argc, char *argv[])
        if (use_syslog)
                closelog();
 
-       return err >= 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+       return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }
 
 #ifndef KMOD_BUNDLE_TOOL