[PATCH] stop elv_unregister() from rogering other iosched's data, fix locking

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 7 insertions, 0 deletions

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 8da3cf66894c..d2ee2af44b58 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -195,6 +195,12 @@ static void free_as_io_context(struct as_io_context *aic)
         kfree(aic);
 }
 
+static void as_trim(struct io_context *ioc)
+{
+        kfree(ioc->aic);
+        ioc->aic = NULL;
+}
+
 /* Called when the task exits */
 static void exit_as_io_context(struct as_io_context *aic)
 {
@@ -1860,6 +1866,7 @@ static struct elevator_type iosched_as = {
                 .elevator_may_queue_fn =        as_may_queue,
                 .elevator_init_fn =             as_init_queue,
                 .elevator_exit_fn =             as_exit_queue,
+                .trim =                         as_trim,
         },
 
         .elevator_ktype = &as_ktype,