From: Lucas De Marchi <lucas.demarchi@intel.com>
Date: Fri, 20 Sep 2013 06:30:07 +0000 (-0500)
Subject: libkmod: always pass O_NONBLOCK to kernel
X-Git-Tag: v16~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ab8804448377fb6b8854f2dd288608db01bb43b;p=thirdparty%2Fkmod.git

libkmod: always pass O_NONBLOCK to kernel

Not passsing O_NONBLOCK to delete_module() is deprecated since kmod 11
and is being removed from the kernel. Force this flag in libkmod.
---

diff --git a/NEWS b/NEWS
index 8260183f..e028cff5 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,11 @@
+kmod 16
+=======
+
+- New features:
+	- Remove option from libkmod to allow waiting on module removal if
+	  the module is being used. It's dangerous since it can block the
+	  caller indefinitely.
+
 kmod 15
 =======
 
@@ -82,7 +90,7 @@ kmod 11
 	  benefits.
 	- Hide --wait option on rmmod. This feature is being targeted for
 	  removal from kernel. rmmod still accepts this option, but it's hidden
-	  now: man page and usage() says nothing about it and if it's used,
+	  now: man page and usage() say nothing about it and if it's used,
 	  user will get a 10s sleep. This way we can check and help if anyone
 	  is using this feature.
 	- Refactor message logging on all tools, giving proper prefix, routing
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 38741941..3adbb69d 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -738,15 +738,11 @@ extern long delete_module(const char *name, unsigned int flags);
 /**
  * kmod_module_remove_module:
  * @mod: kmod module
- * @flags: flags to pass to Linux kernel when removing the module, valid flags are
+ * @flags: flags to pass to Linux kernel when removing the module. The only valid flag is
  * KMOD_REMOVE_FORCE: force remove module regardless if it's still in
  * use by a kernel subsystem or other process;
- * KMOD_REMOVE_NOWAIT: return immediately. It will fail if the module
- * is in using and KMOD_REMOVE_FORCE is not specified.
- * If this module is in use by any kernel subsystem or process, not using
- * this flag will cause the call to block indefinitely, until the module
- * is not in use anymore. Always use this flag, it's deprecated not using
- * it and the default behavior might change in future to always set it.
+ * KMOD_REMOVE_NOWAIT is always enforced, causing us to pass O_NONBLOCK to
+ * delete_module(2).
  *
  * Remove a module from Linux kernel.
  *
@@ -760,8 +756,9 @@ KMOD_EXPORT int kmod_module_remove_module(struct kmod_module *mod,
 	if (mod == NULL)
 		return -ENOENT;
 
-	/* Filter out other flags */
-	flags &= (KMOD_REMOVE_FORCE | KMOD_REMOVE_NOWAIT);
+	/* Filter out other flags and force ONONBLOCK */
+	flags &= KMOD_REMOVE_FORCE;
+	flags |= KMOD_REMOVE_NOWAIT;
 
 	err = delete_module(mod->name, flags);
 	if (err != 0) {
diff --git a/libkmod/libkmod.h b/libkmod/libkmod.h
index 3397f87e..a7ea2216 100644
--- a/libkmod/libkmod.h
+++ b/libkmod/libkmod.h
@@ -140,7 +140,7 @@ struct kmod_module *kmod_module_get_module(const struct kmod_list *entry);
 /* Removal flags */
 enum kmod_remove {
 	KMOD_REMOVE_FORCE = O_TRUNC,
-	KMOD_REMOVE_NOWAIT = O_NONBLOCK,
+	KMOD_REMOVE_NOWAIT = O_NONBLOCK, /* always set */
 };
 
 /* Insertion flags */