pnfs/blocklayout: serialize GETDEVICEINFO calls
The rpc_pipefs code isn't thread safe, leading to occasional use after
frees when running xfstests generic/241 (dbench).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/1411740170-18611-2-git-send-email-hch@lst.de
Cc: stable@vger.kernel.org # 3.17.x
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/blocklayout/rpc_pipefs.c b/fs/nfs/blocklayout/rpc_pipefs.c
index e966c02..acbf9ca 100644
--- a/fs/nfs/blocklayout/rpc_pipefs.c
+++ b/fs/nfs/blocklayout/rpc_pipefs.c
@@ -65,17 +65,18 @@
dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
+ mutex_lock(&nn->bl_mutex);
bl_pipe_msg.bl_wq = &nn->bl_wq;
b->simple.len += 4; /* single volume */
if (b->simple.len > PAGE_SIZE)
- return -EIO;
+ goto out_unlock;
memset(msg, 0, sizeof(*msg));
msg->len = sizeof(*bl_msg) + b->simple.len;
msg->data = kzalloc(msg->len, gfp_mask);
if (!msg->data)
- goto out;
+ goto out_free_data;
bl_msg = msg->data;
bl_msg->type = BL_DEVICE_MOUNT,
@@ -87,7 +88,7 @@
rc = rpc_queue_upcall(nn->bl_device_pipe, msg);
if (rc < 0) {
remove_wait_queue(&nn->bl_wq, &wq);
- goto out;
+ goto out_free_data;
}
set_current_state(TASK_UNINTERRUPTIBLE);
@@ -97,12 +98,14 @@
if (reply->status != BL_DEVICE_REQUEST_PROC) {
printk(KERN_WARNING "%s failed to decode device: %d\n",
__func__, reply->status);
- goto out;
+ goto out_free_data;
}
dev = MKDEV(reply->major, reply->minor);
-out:
+out_free_data:
kfree(msg->data);
+out_unlock:
+ mutex_unlock(&nn->bl_mutex);
return dev;
}
@@ -232,6 +235,7 @@
struct nfs_net *nn = net_generic(net, nfs_net_id);
struct dentry *dentry;
+ mutex_init(&nn->bl_mutex);
init_waitqueue_head(&nn->bl_wq);
nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
if (IS_ERR(nn->bl_device_pipe))
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index ef221fb..f0e06e4 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -19,6 +19,7 @@
struct rpc_pipe *bl_device_pipe;
struct bl_dev_msg bl_mount_reply;
wait_queue_head_t bl_wq;
+ struct mutex bl_mutex;
struct list_head nfs_client_list;
struct list_head nfs_volume_list;
#if IS_ENABLED(CONFIG_NFS_V4)