NFSv4: Ensure that nfs4_do_close() doesn't race with umount

nfs4_do_close() does not currently have any way to ensure that the user
won't attempt to unmount the partition while the asynchronous RPC call
is completing. This again may cause Oopses in nfs_update_inode().

Add a vfsmount argument to nfs4_close_state to ensure that the partition
remains mounted while we're closing the file.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 20 insertions, 15 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 895e8e6..8feaf23 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -453,7 +453,7 @@ static int nfs4_open_recover(struct nfs4_opendata *opendata, struct nfs4_state *
 						opendata->owner->so_cred,
 						&opendata->o_res);
 		}
-		nfs4_close_state(newstate, opendata->o_arg.open_flags);
+		nfs4_close_state(&opendata->path, newstate, opendata->o_arg.open_flags);
 	}
 	if (newstate != state)
 		return -ESTALE;
@@ -603,7 +603,7 @@ static void nfs4_open_confirm_release(void *calldata)
 	nfs_confirm_seqid(&data->owner->so_seqid, 0);
 	state = nfs4_opendata_to_nfs4_state(data);
 	if (state != NULL)
-		nfs4_close_state(state, data->o_arg.open_flags);
+		nfs4_close_state(&data->path, state, data->o_arg.open_flags);
 out_free:
 	nfs4_opendata_free(data);
 }
@@ -706,7 +706,7 @@ static void nfs4_open_release(void *calldata)
 	nfs_confirm_seqid(&data->owner->so_seqid, 0);
 	state = nfs4_opendata_to_nfs4_state(data);
 	if (state != NULL)
-		nfs4_close_state(state, data->o_arg.open_flags);
+		nfs4_close_state(&data->path, state, data->o_arg.open_flags);
 out_free:
 	nfs4_opendata_free(data);
 }
@@ -1103,6 +1103,7 @@ static int nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
 }
 
 struct nfs4_closedata {
+	struct path path;
 	struct inode *inode;
 	struct nfs4_state *state;
 	struct nfs_closeargs arg;
@@ -1119,6 +1120,8 @@ static void nfs4_free_closedata(void *data)
 	nfs4_put_open_state(calldata->state);
 	nfs_free_seqid(calldata->arg.seqid);
 	nfs4_put_state_owner(sp);
+	dput(calldata->path.dentry);
+	mntput(calldata->path.mnt);
 	kfree(calldata);
 }
 
@@ -1211,18 +1214,18 @@ static const struct rpc_call_ops nfs4_close_ops = {
  *
  * NOTE: Caller must be holding the sp->so_owner semaphore!
  */
-int nfs4_do_close(struct inode *inode, struct nfs4_state *state) 
+int nfs4_do_close(struct path *path, struct nfs4_state *state)
 {
-	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_server *server = NFS_SERVER(state->inode);
 	struct nfs4_closedata *calldata;
 	int status = -ENOMEM;
 
 	calldata = kmalloc(sizeof(*calldata), GFP_KERNEL);
 	if (calldata == NULL)
 		goto out;
-	calldata->inode = inode;
+	calldata->inode = state->inode;
 	calldata->state = state;
-	calldata->arg.fh = NFS_FH(inode);
+	calldata->arg.fh = NFS_FH(state->inode);
 	calldata->arg.stateid = &state->stateid;
 	/* Serialization for the sequence id */
 	calldata->arg.seqid = nfs_alloc_seqid(&state->owner->so_seqid);
@@ -1231,6 +1234,8 @@ int nfs4_do_close(struct inode *inode, struct nfs4_state *state)
 	calldata->arg.bitmask = server->attr_bitmask;
 	calldata->res.fattr = &calldata->fattr;
 	calldata->res.server = server;
+	calldata->path.mnt = mntget(path->mnt);
+	calldata->path.dentry = dget(path->dentry);
 
 	status = nfs4_call_async(server->client, &nfs4_close_ops, calldata);
 	if (status == 0)
@@ -1243,18 +1248,18 @@ out:
 	return status;
 }
 
-static int nfs4_intent_set_file(struct nameidata *nd, struct dentry *dentry, struct nfs4_state *state)
+static int nfs4_intent_set_file(struct nameidata *nd, struct path *path, struct nfs4_state *state)
 {
 	struct file *filp;
 
-	filp = lookup_instantiate_filp(nd, dentry, NULL);
+	filp = lookup_instantiate_filp(nd, path->dentry, NULL);
 	if (!IS_ERR(filp)) {
 		struct nfs_open_context *ctx;
 		ctx = (struct nfs_open_context *)filp->private_data;
 		ctx->state = state;
 		return 0;
 	}
-	nfs4_close_state(state, nd->intent.open.flags);
+	nfs4_close_state(path, state, nd->intent.open.flags);
 	return PTR_ERR(filp);
 }
 
@@ -1293,7 +1298,7 @@ nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 	res = d_add_unique(dentry, igrab(state->inode));
 	if (res != NULL)
 		dentry = res;
-	nfs4_intent_set_file(nd, dentry, state);
+	nfs4_intent_set_file(nd, &path, state);
 	return res;
 }
 
@@ -1328,10 +1333,10 @@ nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, st
 		}
 	}
 	if (state->inode == dentry->d_inode) {
-		nfs4_intent_set_file(nd, dentry, state);
+		nfs4_intent_set_file(nd, &path, state);
 		return 1;
 	}
-	nfs4_close_state(state, openflags);
+	nfs4_close_state(&path, state, openflags);
 out_drop:
 	d_drop(dentry);
 	return 0;
@@ -1789,9 +1794,9 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 			nfs_setattr_update_inode(state->inode, sattr);
 	}
 	if (status == 0 && (nd->flags & LOOKUP_OPEN) != 0)
-		status = nfs4_intent_set_file(nd, dentry, state);
+		status = nfs4_intent_set_file(nd, &path, state);
 	else
-		nfs4_close_state(state, flags);
+		nfs4_close_state(&path, state, flags);
 out:
 	return status;
 }