NFS client bugfixes for Linux 5.7

Highlights include:
 
 Stable fixes:
 - nfs: fix NULL deference in nfs4_get_valid_delegation
 
 Bugfixes:
 - Fix corruption of the return value in cachefiles_read_or_alloc_pages()
 - Fix several fscache cookie issues
 - Fix a fscache queuing race that can trigger a BUG_ON
 - NFS: Fix 2 use-after-free regressions due to the RPC_TASK_CRED_NOREF flag
 - SUNRPC: Fix a use-after-free regression in rpc_free_client_work()
 - SUNRPC: Fix a race when tearing down the rpc client debugfs directory
 - SUNRPC: Signalled ASYNC tasks need to exit
 - NFSv3: fix rpc receive buffer size for MOUNT call
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Merge tag 'nfs-for-5.7-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - nfs: fix NULL deference in nfs4_get_valid_delegation

  Bugfixes:
   - Fix corruption of the return value in cachefiles_read_or_alloc_pages()
   - Fix several fscache cookie issues
   - Fix a fscache queuing race that can trigger a BUG_ON
   - NFS: Fix two use-after-free regressions due to the RPC_TASK_CRED_NOREF flag
   - SUNRPC: Fix a use-after-free regression in rpc_free_client_work()
   - SUNRPC: Fix a race when tearing down the rpc client debugfs directory
   - SUNRPC: Signalled ASYNC tasks need to exit
   - NFSv3: fix rpc receive buffer size for MOUNT call"

* tag 'nfs-for-5.7-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv3: fix rpc receive buffer size for MOUNT call
  SUNRPC: 'Directory with parent 'rpc_clnt' already present!'
  NFS/pnfs: Don't use RPC_TASK_CRED_NOREF with pnfs
  NFS: Don't use RPC_TASK_CRED_NOREF with delegreturn
  SUNRPC: Signalled ASYNC tasks need to exit
  nfs: fix NULL deference in nfs4_get_valid_delegation
  SUNRPC: fix use-after-free in rpc_free_client_work()
  cachefiles: Fix race between read_waiter and read_copier involving op->to_do
  NFSv4: Fix fscache cookie aux_data to ensure change_attr is included
  NFS: Fix fscache super_cookie allocation
  NFS: Fix fscache super_cookie index_key from changing after umount
  cachefiles: Fix corruption of the return value in cachefiles_read_or_alloc_pages()

fs/cachefiles/rdwr.c

@@ -60,9 +60,9 @@ static int cachefiles_read_waiter(wait_queue_entry_t *wait, unsigned mode,
 	object = container_of(op->op.object, struct cachefiles_object, fscache);
 	spin_lock(&object->work_lock);
 	list_add_tail(&monitor->op_link, &op->to_do);
+	fscache_enqueue_retrieval(op);
 	spin_unlock(&object->work_lock);
 
-	fscache_enqueue_retrieval(op);
 	fscache_put_retrieval(op);
 	return 0;
 }
@@ -398,7 +398,7 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 	struct inode *inode;
 	sector_t block;
 	unsigned shift;
-	int ret;
+	int ret, ret2;
 
 	object = container_of(op->op.object,
 			      struct cachefiles_object, fscache);
@@ -430,8 +430,8 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 	block = page->index;
 	block <<= shift;
 
-	ret = bmap(inode, &block);
-	ASSERT(ret < 0);
+	ret2 = bmap(inode, &block);
+	ASSERT(ret2 == 0);
 
 	_debug("%llx -> %llx",
 	       (unsigned long long) (page->index << shift),
@@ -739,8 +739,8 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 		block = page->index;
 		block <<= shift;
 
-		ret = bmap(inode, &block);
-		ASSERT(!ret);
+		ret2 = bmap(inode, &block);
+		ASSERT(ret2 == 0);
 
 		_debug("%llx -> %llx",
 		       (unsigned long long) (page->index << shift),

fs/nfs/fscache.c

@@ -118,8 +118,6 @@ void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int
 
 	nfss->fscache_key = NULL;
 	nfss->fscache = NULL;
-	if (!(nfss->options & NFS_OPTION_FSCACHE))
-		return;
 	if (!uniq) {
 		uniq = "";
 		ulen = 1;
@@ -188,7 +186,8 @@ void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int
 	/* create a cache index for looking up filehandles */
 	nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache,
 					       &nfs_fscache_super_index_def,
-					       key, sizeof(*key) + ulen,
+					       &key->key,
+					       sizeof(key->key) + ulen,
 					       NULL, 0,
 					       nfss, 0, true);
 	dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n",
@@ -226,6 +225,19 @@ void nfs_fscache_release_super_cookie(struct super_block *sb)
 	}
 }
 
+static void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
+				  struct nfs_inode *nfsi)
+{
+	memset(auxdata, 0, sizeof(*auxdata));
+	auxdata->mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
+	auxdata->mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
+	auxdata->ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
+	auxdata->ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
+
+	if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
+		auxdata->change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
+}
+
 /*
  * Initialise the per-inode cache cookie pointer for an NFS inode.
  */
@@ -239,14 +251,7 @@ void nfs_fscache_init_inode(struct inode *inode)
 	if (!(nfss->fscache && S_ISREG(inode->i_mode)))
 		return;
 
-	memset(&auxdata, 0, sizeof(auxdata));
-	auxdata.mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
-	auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
-	auxdata.ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
-	auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
-
-	if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
-		auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
+	nfs_fscache_update_auxdata(&auxdata, nfsi);
 
 	nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
 					       &nfs_fscache_inode_object_def,
@@ -266,11 +271,7 @@ void nfs_fscache_clear_inode(struct inode *inode)
 
 	dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie);
 
-	memset(&auxdata, 0, sizeof(auxdata));
-	auxdata.mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
-	auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
-	auxdata.ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
-	auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
+	nfs_fscache_update_auxdata(&auxdata, nfsi);
 	fscache_relinquish_cookie(cookie, &auxdata, false);
 	nfsi->fscache = NULL;
 }
@@ -310,11 +311,7 @@ void nfs_fscache_open_file(struct inode *inode, struct file *filp)
 	if (!fscache_cookie_valid(cookie))
 		return;
 
-	memset(&auxdata, 0, sizeof(auxdata));
-	auxdata.mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
-	auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
-	auxdata.ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
-	auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
+	nfs_fscache_update_auxdata(&auxdata, nfsi);
 
 	if (inode_is_open_for_write(inode)) {
 		dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);

fs/nfs/mount_clnt.c

@@ -30,6 +30,7 @@
 #define encode_dirpath_sz	(1 + XDR_QUADLEN(MNTPATHLEN))
 #define MNT_status_sz		(1)
 #define MNT_fhandle_sz		XDR_QUADLEN(NFS2_FHSIZE)
+#define MNT_fhandlev3_sz	XDR_QUADLEN(NFS3_FHSIZE)
 #define MNT_authflav3_sz	(1 + NFS_MAX_SECFLAVORS)
 
 /*
@@ -37,7 +38,7 @@
  */
 #define MNT_enc_dirpath_sz	encode_dirpath_sz
 #define MNT_dec_mountres_sz	(MNT_status_sz + MNT_fhandle_sz)
-#define MNT_dec_mountres3_sz	(MNT_status_sz + MNT_fhandle_sz + \
+#define MNT_dec_mountres3_sz	(MNT_status_sz + MNT_fhandlev3_sz + \
 				 MNT_authflav3_sz)
 
 /*

fs/nfs/nfs4proc.c

@@ -6347,7 +6347,7 @@ static int _nfs4_proc_delegreturn(struct inode *inode, const struct cred *cred,
 		.rpc_client = server->client,
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_delegreturn_ops,
-		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF | RPC_TASK_TIMEOUT,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_TIMEOUT,
 	};
 	int status = 0;
 

fs/nfs/nfs4state.c

@@ -734,9 +734,9 @@ nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 		state = new;
 		state->owner = owner;
 		atomic_inc(&owner->so_count);
-		list_add_rcu(&state->inode_states, &nfsi->open_states);
 		ihold(inode);
 		state->inode = inode;
+		list_add_rcu(&state->inode_states, &nfsi->open_states);
 		spin_unlock(&inode->i_lock);
 		/* Note: The reclaim code dictates that we add stateless
 		 * and read-only stateids to the end of the list */

fs/nfs/pagelist.c

@@ -752,7 +752,7 @@ int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
 		.callback_ops = call_ops,
 		.callback_data = hdr,
 		.workqueue = nfsiod_workqueue,
-		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF | flags,
+		.flags = RPC_TASK_ASYNC | flags,
 	};
 
 	hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
@@ -950,7 +950,8 @@ static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
 					hdr->cred,
 					NFS_PROTO(hdr->inode),
 					desc->pg_rpc_callops,
-					desc->pg_ioflags, 0);
+					desc->pg_ioflags,
+					RPC_TASK_CRED_NOREF);
 	return ret;
 }
 

fs/nfs/pnfs_nfs.c

@@ -536,7 +536,8 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 			nfs_init_commit(data, NULL, NULL, cinfo);
 			nfs_initiate_commit(NFS_CLIENT(inode), data,
 					    NFS_PROTO(data->inode),
-					    data->mds_ops, how, 0);
+					    data->mds_ops, how,
+					    RPC_TASK_CRED_NOREF);
 		} else {
 			nfs_init_commit(data, NULL, data->lseg, cinfo);
 			initiate_commit(data, how);

fs/nfs/super.c

@@ -1189,7 +1189,6 @@ static void nfs_get_cache_cookie(struct super_block *sb,
 			uniq = ctx->fscache_uniq;
 			ulen = strlen(ctx->fscache_uniq);
 		}
-		return;
 	}
 
 	nfs_fscache_get_super_cookie(sb, uniq, ulen);

fs/nfs/write.c

@@ -1695,7 +1695,7 @@ int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
 		.callback_ops = call_ops,
 		.callback_data = data,
 		.workqueue = nfsiod_workqueue,
-		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF | flags,
+		.flags = RPC_TASK_ASYNC | flags,
 		.priority = priority,
 	};
 	/* Set up the initial task struct.  */
@@ -1813,7 +1813,7 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how,
 	nfs_init_commit(data, head, NULL, cinfo);
 	atomic_inc(&cinfo->mds->rpcs_out);
 	return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
-				   data->mds_ops, how, 0);
+				   data->mds_ops, how, RPC_TASK_CRED_NOREF);
 }
 
 /*

net/sunrpc/clnt.c

@@ -889,7 +889,9 @@ static void rpc_free_client_work(struct work_struct *work)
 	 * here.
 	 */
 	rpc_clnt_debugfs_unregister(clnt);
+	rpc_free_clid(clnt);
 	rpc_clnt_remove_pipedir(clnt);
+	xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 
 	kfree(clnt);
 	rpciod_down();
@@ -907,10 +909,8 @@ rpc_free_client(struct rpc_clnt *clnt)
 	rpc_unregister_client(clnt);
 	rpc_free_iostats(clnt->cl_metrics);
 	clnt->cl_metrics = NULL;
-	xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 	xprt_iter_destroy(&clnt->cl_xpi);
 	put_cred(clnt->cl_cred);
-	rpc_free_clid(clnt);
 
 	INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 	schedule_work(&clnt->cl_work);
@@ -2433,6 +2433,11 @@ rpc_check_timeout(struct rpc_task *task)
 {
 	struct rpc_clnt	*clnt = task->tk_client;
 
+	if (RPC_SIGNALLED(task)) {
+		rpc_call_rpcerror(task, -ERESTARTSYS);
+		return;
+	}
+
 	if (xprt_adjust_timeout(task->tk_rqstp) == 0)
 		return;