The patch below does not apply to the 3.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From e0d4ed71ca0344494722a041780f004d2bcf0f11 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig <hch@xxxxxx> Date: Fri, 26 Sep 2014 16:02:50 +0200 Subject: [PATCH] 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@xxxxxx> Link: http://lkml.kernel.org/r/1411740170-18611-2-git-send-email-hch@xxxxxx Cc: stable@xxxxxxxxxxxxxxx # 3.17.x Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> diff --git a/fs/nfs/blocklayout/rpc_pipefs.c b/fs/nfs/blocklayout/rpc_pipefs.c index e966c023b1b7..acbf9ca4018c 100644 --- a/fs/nfs/blocklayout/rpc_pipefs.c +++ b/fs/nfs/blocklayout/rpc_pipefs.c @@ -65,17 +65,18 @@ bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b, 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 @@ bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b, 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 @@ bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b, 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 @@ static int nfs4blocklayout_net_init(struct net *net) 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 ef221fb8a183..f0e06e4acbef 100644 --- a/fs/nfs/netns.h +++ b/fs/nfs/netns.h @@ -19,6 +19,7 @@ struct nfs_net { 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) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html