block: Fix io_context leak after failure of clone with CLONE_IO
With CLONE_IO, parent's io_context->nr_tasks is incremented, but never
decremented whenever copy_process() fails afterwards, which prevents
exit_io_context() from calling IO schedulers exit functions.
Give a task_struct to exit_io_context(), and call exit_io_context() instead of
put_io_context() in copy_process() cleanup path.
Signed-off-by: Louis Rilling <louis.rilling@kerlabs.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index dcd0412..cbdabb0 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -66,14 +66,14 @@
}
/* Called by the exitting task */
-void exit_io_context(void)
+void exit_io_context(struct task_struct *task)
{
struct io_context *ioc;
- task_lock(current);
- ioc = current->io_context;
- current->io_context = NULL;
- task_unlock(current);
+ task_lock(task);
+ ioc = task->io_context;
+ task->io_context = NULL;
+ task_unlock(task);
if (atomic_dec_and_test(&ioc->nr_tasks)) {
if (ioc->aic && ioc->aic->exit)
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index d61b0b8..a632359 100644
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -98,14 +98,15 @@
return NULL;
}
+struct task_struct;
#ifdef CONFIG_BLOCK
int put_io_context(struct io_context *ioc);
-void exit_io_context(void);
+void exit_io_context(struct task_struct *task);
struct io_context *get_io_context(gfp_t gfp_flags, int node);
struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
#else
-static inline void exit_io_context(void)
+static inline void exit_io_context(struct task_struct *task)
{
}
diff --git a/kernel/exit.c b/kernel/exit.c
index f7864ac..2544000 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1004,7 +1004,7 @@
tsk->flags |= PF_EXITPIDONE;
if (tsk->io_context)
- exit_io_context();
+ exit_io_context(tsk);
if (tsk->splice_pipe)
__free_pipe_info(tsk->splice_pipe);
diff --git a/kernel/fork.c b/kernel/fork.c
index 166b8c4..6073534 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1310,7 +1310,8 @@
if (pid != &init_struct_pid)
free_pid(pid);
bad_fork_cleanup_io:
- put_io_context(p->io_context);
+ if (p->io_context)
+ exit_io_context(p);
bad_fork_cleanup_namespaces:
exit_task_namespaces(p);
bad_fork_cleanup_mm: