Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull pstore updates from Tony Luck:
 "Half dozen small cleanups plus change to allow pstore backend drivers
  to be unloaded"

* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  pstore: fix code comment to match code
  efi-pstore: fix kernel-doc argument name
  pstore: Fix return type of pstore_is_mounted()
  pstore: add pstore unregister
  pstore: add a helper function pstore_register_kmsg
  pstore: add vmalloc error check

1 files changed, 44 insertions, 3 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 791743deedf1..588461bb2dd4 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -237,6 +237,14 @@ static void allocate_buf_for_compression(void)
 
 }
 
+static void free_buf_for_compression(void)
+{
+	kfree(stream.workspace);
+	stream.workspace = NULL;
+	kfree(big_oops_buf);
+	big_oops_buf = NULL;
+}
+
 /*
  * Called when compression fails, since the printk buffer
  * would be fetched for compression calling it again when
@@ -353,6 +361,19 @@ static struct kmsg_dumper pstore_dumper = {
 	.dump = pstore_dump,
 };
 
+/*
+ * Register with kmsg_dump to save last part of console log on panic.
+ */
+static void pstore_register_kmsg(void)
+{
+	kmsg_dump_register(&pstore_dumper);
+}
+
+static void pstore_unregister_kmsg(void)
+{
+	kmsg_dump_unregister(&pstore_dumper);
+}
+
 #ifdef CONFIG_PSTORE_CONSOLE
 static void pstore_console_write(struct console *con, const char *s, unsigned c)
 {
@@ -390,8 +411,14 @@ static void pstore_register_console(void)
 {
 	register_console(&pstore_console);
 }
+
+static void pstore_unregister_console(void)
+{
+	unregister_console(&pstore_console);
+}
 #else
 static void pstore_register_console(void) {}
+static void pstore_unregister_console(void) {}
 #endif
 
 static int pstore_write_compat(enum pstore_type_id type,
@@ -410,8 +437,6 @@ static int pstore_write_compat(enum pstore_type_id type,
  * read function right away to populate the file system. If not
  * then the pstore mount code will call us later to fill out
  * the file system.
- *
- * Register with kmsg_dump to save last part of console log on panic.
  */
 int pstore_register(struct pstore_info *psi)
 {
@@ -442,7 +467,7 @@ int pstore_register(struct pstore_info *psi)
 	if (pstore_is_mounted())
 		pstore_get_records(0);
 
-	kmsg_dump_register(&pstore_dumper);
+	pstore_register_kmsg();
 
 	if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
 		pstore_register_console();
@@ -462,12 +487,28 @@ int pstore_register(struct pstore_info *psi)
 	 */
 	backend = psi->name;
 
+	module_put(owner);
+
 	pr_info("Registered %s as persistent store backend\n", psi->name);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_register);
 
+void pstore_unregister(struct pstore_info *psi)
+{
+	pstore_unregister_pmsg();
+	pstore_unregister_ftrace();
+	pstore_unregister_console();
+	pstore_unregister_kmsg();
+
+	free_buf_for_compression();
+
+	psinfo = NULL;
+	backend = NULL;
+}
+EXPORT_SYMBOL_GPL(pstore_unregister);
+
 /*
  * Read all the records from the persistent store. Create
  * files in our filesystem.  Don't warn about -EEXIST errors