pstore: add pstore unregister
pstore doesn't support unregistering yet. It was marked as TODO.
This patch adds some code to fix it:
1) Add functions to unregister kmsg/console/ftrace/pmsg.
2) Add a function to free compression buffer.
3) Unmap the memory and free it.
4) Add a function to unregister pstore filesystem.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Kees Cook <keescook@chromium.org>
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 1b11249..0aab920 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -237,6 +237,14 @@
}
+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
@@ -358,6 +366,11 @@
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)
{
@@ -395,8 +408,14 @@
{
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,
@@ -467,12 +486,28 @@
*/
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