[PATCH] don't do exit_io_context() until we know we won't be doing any IO
testcase:
mount /dev/sdb10 /mnt
touch /mnt/tmp/b
umount /mnt
mount /dev/sdb10 /mnt
rm /mnt/tmp/b </mnt/tmp/b
umount /mnt
and watch blkdev_ioc line in /proc/slabinfo. Vanilla kernel leaks.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/exit.c b/kernel/exit.c
index 531aadc..d1e8d500 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -807,8 +807,6 @@
panic("Attempted to kill the idle task!");
if (unlikely(tsk->pid == 1))
panic("Attempted to kill init!");
- if (tsk->io_context)
- exit_io_context();
if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
current->ptrace_message = code;
@@ -822,6 +820,8 @@
if (unlikely(tsk->flags & PF_EXITING)) {
printk(KERN_ALERT
"Fixing recursive fault but reboot is needed!\n");
+ if (tsk->io_context)
+ exit_io_context();
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
}
@@ -881,6 +881,9 @@
*/
mutex_debug_check_no_locks_held(tsk);
+ if (tsk->io_context)
+ exit_io_context();
+
/* PF_DEAD causes final put_task_struct after we schedule. */
preempt_disable();
BUG_ON(tsk->flags & PF_DEAD);