1 files changed, 27 insertions, 4 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index b3086e99420c..f0f0fb7499e3 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -49,6 +49,7 @@
 #include <linux/workqueue.h>
 #include <linux/bitops.h>
 #include <linux/jiffies.h>
+#include <linux/sched/mm.h>
 
 #include <linux/sunrpc/clnt.h>
 
@@ -65,6 +66,8 @@
 
 #define OPENOWNER_POOL_SIZE	8
 
+static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp);
+
 const nfs4_stateid zero_stateid = {
 	{ .data = { 0 } },
 	.type = NFS4_SPECIAL_STATEID_TYPE,
@@ -337,6 +340,8 @@ do_confirm:
 	status = nfs4_proc_create_session(clp, cred);
 	if (status != 0)
 		goto out;
+	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R))
+		nfs4_state_start_reclaim_reboot(clp);
 	nfs41_finish_session_reset(clp);
 	nfs_mark_client_ready(clp, NFS_CS_READY);
 out:
@@ -674,7 +679,7 @@ nfs4_alloc_open_state(void)
 	state = kzalloc(sizeof(*state), GFP_NOFS);
 	if (!state)
 		return NULL;
-	atomic_set(&state->count, 1);
+	refcount_set(&state->count, 1);
 	INIT_LIST_HEAD(&state->lock_states);
 	spin_lock_init(&state->state_lock);
 	seqlock_init(&state->seqlock);
@@ -708,7 +713,7 @@ __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 			continue;
 		if (!nfs4_valid_open_stateid(state))
 			continue;
-		if (atomic_inc_not_zero(&state->count))
+		if (refcount_inc_not_zero(&state->count))
 			return state;
 	}
 	return NULL;
@@ -762,7 +767,7 @@ void nfs4_put_open_state(struct nfs4_state *state)
 	struct inode *inode = state->inode;
 	struct nfs4_state_owner *owner = state->owner;
 
-	if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
+	if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 		return;
 	spin_lock(&inode->i_lock);
 	list_del(&state->inode_states);
@@ -1246,6 +1251,8 @@ void nfs4_schedule_state_manager(struct nfs_client *clp)
 	if (IS_ERR(task)) {
 		printk(KERN_ERR "%s: kthread_run: %ld\n",
 			__func__, PTR_ERR(task));
+		if (!nfs_client_init_is_complete(clp))
+			nfs_mark_client_ready(clp, PTR_ERR(task));
 		nfs4_clear_state_manager_bit(clp);
 		nfs_put_client(clp);
 		module_put(THIS_MODULE);
@@ -1593,7 +1600,7 @@ restart:
 			continue;
 		if (state->state == 0)
 			continue;
-		atomic_inc(&state->count);
+		refcount_inc(&state->count);
 		spin_unlock(&sp->so_lock);
 		status = ops->recover_open(sp, state);
 		if (status >= 0) {
@@ -1735,6 +1742,7 @@ static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
 
 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
 {
+	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
 	/* Mark all delegations for reclaim */
 	nfs_delegation_mark_reclaim(clp);
 	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
@@ -2066,6 +2074,9 @@ static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
 	}
 
 	result = -NFS4ERR_NXIO;
+	if (!locations->nlocations)
+		goto out;
+
 	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
 		dprintk("<-- %s: No fs_locations data, migration skipped\n",
 			__func__);
@@ -2502,9 +2513,17 @@ static int nfs4_bind_conn_to_session(struct nfs_client *clp)
 
 static void nfs4_state_manager(struct nfs_client *clp)
 {
+	unsigned int memflags;
 	int status = 0;
 	const char *section = "", *section_sep = "";
 
+	/*
+	 * State recovery can deadlock if the direct reclaim code tries
+	 * start NFS writeback. So ensure memory allocations are all
+	 * GFP_NOFS.
+	 */
+	memflags = memalloc_nofs_save();
+
 	/* Ensure exclusive access to NFSv4 state */
 	do {
 		clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
@@ -2577,6 +2596,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 			if (status < 0)
 				goto out_error;
 			nfs4_state_end_reclaim_reboot(clp);
+			continue;
 		}
 
 		/* Detect expired delegations... */
@@ -2597,6 +2617,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 				goto out_error;
 		}
 
+		memalloc_nofs_restore(memflags);
 		nfs4_end_drain_session(clp);
 		nfs4_clear_state_manager_bit(clp);
 
@@ -2613,6 +2634,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 			return;
 		if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
 			return;
+		memflags = memalloc_nofs_save();
 	} while (refcount_read(&clp->cl_count) > 1 && !signalled());
 	goto out_drain;
 
@@ -2624,6 +2646,7 @@ out_error:
 			clp->cl_hostname, -status);
 	ssleep(1);
 out_drain:
+	memalloc_nofs_restore(memflags);
 	nfs4_end_drain_session(clp);
 	nfs4_clear_state_manager_bit(clp);
 }