Linux 6.5 compat: safe cleanup in spl_proc_fini()

If we fail to create a proc entry in spl_proc_init() we may end up
calling unregister_sysctl_table() twice: one in the failure path of
spl_proc_init() and another time during spl_proc_fini().

Avoid the double call to unregister_sysctl_table() and while at it
refactor the code a bit to reduce code duplication.

This was accidentally introduced when the spl code was
updated for Linux 6.5 compatibility.

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Ameer Hamza <[email protected]>
Signed-off-by: Andrea Righi <[email protected]>
Closes #15234 
Closes #15235 

1 files changed, 18 insertions, 18 deletions

diff --git a/module/os/linux/spl/spl-proc.c b/module/os/linux/spl/spl-proc.c
index bcc356ae5..5cb5a6dad 100644
--- a/module/os/linux/spl/spl-proc.c
+++ b/module/os/linux/spl/spl-proc.c
@@ -659,6 +659,21 @@ static struct ctl_table spl_root[] = {
 };
 #endif
 
+static void spl_proc_cleanup(void)
+{
+	remove_proc_entry("kstat", proc_spl);
+	remove_proc_entry("slab", proc_spl_kmem);
+	remove_proc_entry("kmem", proc_spl);
+	remove_proc_entry("taskq-all", proc_spl);
+	remove_proc_entry("taskq", proc_spl);
+	remove_proc_entry("spl", NULL);
+
+	if (spl_header) {
+		unregister_sysctl_table(spl_header);
+		spl_header = NULL;
+	}
+}
+
 int
 spl_proc_init(void)
 {
@@ -723,15 +738,8 @@ spl_proc_init(void)
 		goto out;
 	}
 out:
-	if (rc) {
-		remove_proc_entry("kstat", proc_spl);
-		remove_proc_entry("slab", proc_spl_kmem);
-		remove_proc_entry("kmem", proc_spl);
-		remove_proc_entry("taskq-all", proc_spl);
-		remove_proc_entry("taskq", proc_spl);
-		remove_proc_entry("spl", NULL);
-		unregister_sysctl_table(spl_header);
-	}
+	if (rc)
+		spl_proc_cleanup();
 
 	return (rc);
 }
@@ -739,13 +747,5 @@ out:
 void
 spl_proc_fini(void)
 {
-	remove_proc_entry("kstat", proc_spl);
-	remove_proc_entry("slab", proc_spl_kmem);
-	remove_proc_entry("kmem", proc_spl);
-	remove_proc_entry("taskq-all", proc_spl);
-	remove_proc_entry("taskq", proc_spl);
-	remove_proc_entry("spl", NULL);
-
-	ASSERT(spl_header != NULL);
-	unregister_sysctl_table(spl_header);
+	spl_proc_cleanup();
 }