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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 16 Feb 2015 18:49:10 +0100
Subject: [PATCH 096/354] fs/aio: simple simple work
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=6f2737df5a64e62bdf8d1c34ff2b5d1ce6274d83
|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:768
|in_atomic(): 1, irqs_disabled(): 0, pid: 26, name: rcuos/2
|2 locks held by rcuos/2/26:
| #0: (rcu_callback){.+.+..}, at: [<ffffffff810b1a12>] rcu_nocb_kthread+0x1e2/0x380
| #1: (rcu_read_lock_sched){.+.+..}, at: [<ffffffff812acd26>] percpu_ref_kill_rcu+0xa6/0x1c0
|Preemption disabled at:[<ffffffff810b1a93>] rcu_nocb_kthread+0x263/0x380
|Call Trace:
| [<ffffffff81582e9e>] dump_stack+0x4e/0x9c
| [<ffffffff81077aeb>] __might_sleep+0xfb/0x170
| [<ffffffff81589304>] rt_spin_lock+0x24/0x70
| [<ffffffff811c5790>] free_ioctx_users+0x30/0x130
| [<ffffffff812ace34>] percpu_ref_kill_rcu+0x1b4/0x1c0
| [<ffffffff810b1a93>] rcu_nocb_kthread+0x263/0x380
| [<ffffffff8106e046>] kthread+0xd6/0xf0
| [<ffffffff81591eec>] ret_from_fork+0x7c/0xb0
replace this preempt_disable() friendly swork.
Reported-By: Mike Galbraith <umgwanakikbuti@gmail.com>
Suggested-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
fs/aio.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index 1bd934eccbf6..ab1bb9260056 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -42,6 +42,7 @@
#include <linux/ramfs.h>
#include <linux/percpu-refcount.h>
#include <linux/mount.h>
+#include <linux/swork.h>
#include <asm/kmap_types.h>
#include <linux/uaccess.h>
@@ -121,6 +122,7 @@ struct kioctx {
long nr_pages;
struct rcu_work free_rwork; /* see free_ioctx() */
+ struct swork_event free_swork; /* see free_ioctx() */
/*
* signals when all in-flight requests are done
@@ -267,6 +269,7 @@ static int __init aio_setup(void)
.mount = aio_mount,
.kill_sb = kill_anon_super,
};
+ BUG_ON(swork_get());
aio_mnt = kern_mount(&aio_fs);
if (IS_ERR(aio_mnt))
panic("Failed to create aio fs mount.");
@@ -612,9 +615,9 @@ static void free_ioctx_reqs(struct percpu_ref *ref)
* and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
* now it's safe to cancel any that need to be.
*/
-static void free_ioctx_users(struct percpu_ref *ref)
+static void free_ioctx_users_work(struct swork_event *sev)
{
- struct kioctx *ctx = container_of(ref, struct kioctx, users);
+ struct kioctx *ctx = container_of(sev, struct kioctx, free_swork);
struct aio_kiocb *req;
spin_lock_irq(&ctx->ctx_lock);
@@ -632,6 +635,14 @@ static void free_ioctx_users(struct percpu_ref *ref)
percpu_ref_put(&ctx->reqs);
}
+static void free_ioctx_users(struct percpu_ref *ref)
+{
+ struct kioctx *ctx = container_of(ref, struct kioctx, users);
+
+ INIT_SWORK(&ctx->free_swork, free_ioctx_users_work);
+ swork_queue(&ctx->free_swork);
+}
+
static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
{
unsigned i, new_nr;
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