1 files changed, 132 insertions, 128 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index cc563cfa6940..968225a88015 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -43,6 +43,27 @@ static void nfs_free_delegation(struct nfs_delegation *delegation)
                 put_rpccred(cred);
 }
 
+void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
+{
+        set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
+}
+
+int nfs_have_delegation(struct inode *inode, fmode_t flags)
+{
+        struct nfs_delegation *delegation;
+        int ret = 0;
+
+        flags &= FMODE_READ|FMODE_WRITE;
+        rcu_read_lock();
+        delegation = rcu_dereference(NFS_I(inode)->delegation);
+        if (delegation != NULL && (delegation->type & flags) == flags) {
+                nfs_mark_delegation_referenced(delegation);
+                ret = 1;
+        }
+        rcu_read_unlock();
+        return ret;
+}
+
 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
 {
         struct inode *inode = state->inode;
@@ -119,7 +140,7 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, st
         delegation->maxsize = res->maxsize;
         oldcred = delegation->cred;
         delegation->cred = get_rpccred(cred);
-        delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
+        clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
         NFS_I(inode)->delegation_state = delegation->type;
         smp_wmb();
         put_rpccred(oldcred);
@@ -134,19 +155,35 @@ static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *
         return res;
 }
 
+static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
+{
+        struct inode *inode = NULL;
+
+        spin_lock(&delegation->lock);
+        if (delegation->inode != NULL)
+                inode = igrab(delegation->inode);
+        spin_unlock(&delegation->lock);
+        return inode;
+}
+
 static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
 {
         struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
 
         if (delegation == NULL)
                 goto nomatch;
+        spin_lock(&delegation->lock);
         if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
                                 sizeof(delegation->stateid.data)) != 0)
-                goto nomatch;
+                goto nomatch_unlock;
         list_del_rcu(&delegation->super_list);
+        delegation->inode = NULL;
         nfsi->delegation_state = 0;
         rcu_assign_pointer(nfsi->delegation, NULL);
+        spin_unlock(&delegation->lock);
         return delegation;
+nomatch_unlock:
+        spin_unlock(&delegation->lock);
 nomatch:
         return NULL;
 }
@@ -172,6 +209,8 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
         delegation->change_attr = nfsi->change_attr;
         delegation->cred = get_rpccred(cred);
         delegation->inode = inode;
+        delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
+        spin_lock_init(&delegation->lock);
 
         spin_lock(&clp->cl_lock);
         if (rcu_dereference(nfsi->delegation) != NULL) {
@@ -226,22 +265,47 @@ static void nfs_msync_inode(struct inode *inode)
  */
 static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
 {
-        struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
         struct nfs_inode *nfsi = NFS_I(inode);
 
         nfs_msync_inode(inode);
-        down_read(&clp->cl_sem);
         /* Guard against new delegated open calls */
         down_write(&nfsi->rwsem);
         nfs_delegation_claim_opens(inode, &delegation->stateid);
         up_write(&nfsi->rwsem);
-        up_read(&clp->cl_sem);
         nfs_msync_inode(inode);
 
         return nfs_do_return_delegation(inode, delegation, 1);
 }
 
 /*
+ * Return all delegations that have been marked for return
+ */
+void nfs_client_return_marked_delegations(struct nfs_client *clp)
+{
+        struct nfs_delegation *delegation;
+        struct inode *inode;
+
+restart:
+        rcu_read_lock();
+        list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
+                if (!test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
+                        continue;
+                inode = nfs_delegation_grab_inode(delegation);
+                if (inode == NULL)
+                        continue;
+                spin_lock(&clp->cl_lock);
+                delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
+                spin_unlock(&clp->cl_lock);
+                rcu_read_unlock();
+                if (delegation != NULL)
+                        __nfs_inode_return_delegation(inode, delegation);
+                iput(inode);
+                goto restart;
+        }
+        rcu_read_unlock();
+}
+
+/*
  * This function returns the delegation without reclaiming opens
  * or protecting against delegation reclaims.
  * It is therefore really only safe to be called from
@@ -279,83 +343,55 @@ int nfs_inode_return_delegation(struct inode *inode)
         return err;
 }
 
+static void nfs_mark_return_delegation(struct nfs_client *clp, struct nfs_delegation *delegation)
+{
+        set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
+        set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
+}
+
 /*
  * Return all delegations associated to a super block
  */
-void nfs_return_all_delegations(struct super_block *sb)
+void nfs_super_return_all_delegations(struct super_block *sb)
 {
         struct nfs_client *clp = NFS_SB(sb)->nfs_client;
         struct nfs_delegation *delegation;
-        struct inode *inode;
 
         if (clp == NULL)
                 return;
-restart:
         rcu_read_lock();
         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
-                if (delegation->inode->i_sb != sb)
-                        continue;
-                inode = igrab(delegation->inode);
-                if (inode == NULL)
-                        continue;
-                spin_lock(&clp->cl_lock);
-                delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
-                spin_unlock(&clp->cl_lock);
-                rcu_read_unlock();
-                if (delegation != NULL)
-                        __nfs_inode_return_delegation(inode, delegation);
-                iput(inode);
-                goto restart;
+                spin_lock(&delegation->lock);
+                if (delegation->inode != NULL && delegation->inode->i_sb == sb)
+                        set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
+                spin_unlock(&delegation->lock);
         }
         rcu_read_unlock();
+        nfs_client_return_marked_delegations(clp);
 }
 
-static int nfs_do_expire_all_delegations(void *ptr)
+static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
 {
-        struct nfs_client *clp = ptr;
         struct nfs_delegation *delegation;
-        struct inode *inode;
 
-        allow_signal(SIGKILL);
-restart:
-        if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
-                goto out;
-        if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
-                goto out;
         rcu_read_lock();
         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
-                inode = igrab(delegation->inode);
-                if (inode == NULL)
-                        continue;
-                spin_lock(&clp->cl_lock);
-                delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
-                spin_unlock(&clp->cl_lock);
-                rcu_read_unlock();
-                if (delegation)
-                        __nfs_inode_return_delegation(inode, delegation);
-                iput(inode);
-                goto restart;
+                set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
+                set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
         }
         rcu_read_unlock();
-out:
-        nfs_put_client(clp);
-        module_put_and_exit(0);
+}
+
+static void nfs_delegation_run_state_manager(struct nfs_client *clp)
+{
+        if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
+                nfs4_schedule_state_manager(clp);
 }
 
 void nfs_expire_all_delegations(struct nfs_client *clp)
 {
-        struct task_struct *task;
-
-        __module_get(THIS_MODULE);
-        atomic_inc(&clp->cl_count);
-        task = kthread_run(nfs_do_expire_all_delegations, clp,
-                                "%s-delegreturn",
-                                rpc_peeraddr2str(clp->cl_rpcclient,
-                                                        RPC_DISPLAY_ADDR));
-        if (!IS_ERR(task))
-                return;
-        nfs_put_client(clp);
-        module_put(THIS_MODULE);
+        nfs_client_mark_return_all_delegations(clp);
+        nfs_delegation_run_state_manager(clp);
 }
 
 /*
@@ -363,68 +399,29 @@ void nfs_expire_all_delegations(struct nfs_client *clp)
  */
 void nfs_handle_cb_pathdown(struct nfs_client *clp)
 {
-        struct nfs_delegation *delegation;
-        struct inode *inode;
-
         if (clp == NULL)
                 return;
-restart:
+        nfs_client_mark_return_all_delegations(clp);
+}
+
+static void nfs_client_mark_return_unreferenced_delegations(struct nfs_client *clp)
+{
+        struct nfs_delegation *delegation;
+
         rcu_read_lock();
         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
-                inode = igrab(delegation->inode);
-                if (inode == NULL)
+                if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
                         continue;
-                spin_lock(&clp->cl_lock);
-                delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
-                spin_unlock(&clp->cl_lock);
-                rcu_read_unlock();
-                if (delegation != NULL)
-                        __nfs_inode_return_delegation(inode, delegation);
-                iput(inode);
-                goto restart;
+                set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
+                set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
         }
         rcu_read_unlock();
 }
 
-struct recall_threadargs {
-        struct inode *inode;
-        struct nfs_client *clp;
-        const nfs4_stateid *stateid;
-
-        struct completion started;
-        int result;
-};
-
-static int recall_thread(void *data)
+void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
 {
-        struct recall_threadargs *args = (struct recall_threadargs *)data;
-        struct inode *inode = igrab(args->inode);
-        struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
-        struct nfs_inode *nfsi = NFS_I(inode);
-        struct nfs_delegation *delegation;
-
-        daemonize("nfsv4-delegreturn");
-
-        nfs_msync_inode(inode);
-        down_read(&clp->cl_sem);
-        down_write(&nfsi->rwsem);
-        spin_lock(&clp->cl_lock);
-        delegation = nfs_detach_delegation_locked(nfsi, args->stateid);
-        if (delegation != NULL)
-                args->result = 0;
-        else
-                args->result = -ENOENT;
-        spin_unlock(&clp->cl_lock);
-        complete(&args->started);
-        nfs_delegation_claim_opens(inode, args->stateid);
-        up_write(&nfsi->rwsem);
-        up_read(&clp->cl_sem);
-        nfs_msync_inode(inode);
-
-        if (delegation != NULL)
-                nfs_do_return_delegation(inode, delegation, 1);
-        iput(inode);
-        module_put_and_exit(0);
+        nfs_client_mark_return_unreferenced_delegations(clp);
+        nfs_delegation_run_state_manager(clp);
 }
 
 /*
@@ -432,22 +429,20 @@ static int recall_thread(void *data)
  */
 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
 {
-        struct recall_threadargs data = {
-                .inode = inode,
-                .stateid = stateid,
-        };
-        int status;
+        struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+        struct nfs_delegation *delegation;
 
-        init_completion(&data.started);
-        __module_get(THIS_MODULE);
-        status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
-        if (status < 0)
-                goto out_module_put;
-        wait_for_completion(&data.started);
-        return data.result;
-out_module_put:
-        module_put(THIS_MODULE);
-        return status;
+        rcu_read_lock();
+        delegation = rcu_dereference(NFS_I(inode)->delegation);
+        if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
+                                sizeof(delegation->stateid.data)) != 0) {
+                rcu_read_unlock();
+                return -ENOENT;
+        }
+        nfs_mark_return_delegation(clp, delegation);
+        rcu_read_unlock();
+        nfs_delegation_run_state_manager(clp);
+        return 0;
 }
 
 /*
@@ -459,10 +454,14 @@ struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs
         struct inode *res = NULL;
         rcu_read_lock();
         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
-                if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
+                spin_lock(&delegation->lock);
+                if (delegation->inode != NULL &&
+                    nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
                         res = igrab(delegation->inode);
-                        break;
                 }
+                spin_unlock(&delegation->lock);
+                if (res != NULL)
+                        break;
         }
         rcu_read_unlock();
         return res;
@@ -476,7 +475,7 @@ void nfs_delegation_mark_reclaim(struct nfs_client *clp)
         struct nfs_delegation *delegation;
         rcu_read_lock();
         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list)
-                delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
+                set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
         rcu_read_unlock();
 }
 
@@ -486,17 +485,22 @@ void nfs_delegation_mark_reclaim(struct nfs_client *clp)
 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
 {
         struct nfs_delegation *delegation;
+        struct inode *inode;
 restart:
         rcu_read_lock();
         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
-                if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
+                if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) == 0)
+                        continue;
+                inode = nfs_delegation_grab_inode(delegation);
+                if (inode == NULL)
                         continue;
                 spin_lock(&clp->cl_lock);
-                delegation = nfs_detach_delegation_locked(NFS_I(delegation->inode), NULL);
+                delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
                 spin_unlock(&clp->cl_lock);
                 rcu_read_unlock();
                 if (delegation != NULL)
                         nfs_free_delegation(delegation);
+                iput(inode);
                 goto restart;
         }
         rcu_read_unlock();