nfsd: remove pointless paths in file headers
[safe/jmp/linux-2.6] / fs / nfs / delegation.c
index 7a1b6e8..6dd48a4 100644 (file)
@@ -10,6 +10,7 @@
 #include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 
 #include <linux/nfs4.h>
@@ -43,33 +44,51 @@ 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;
        struct file_lock *fl;
-       int status;
+       int status = 0;
+
+       if (inode->i_flock == NULL)
+               goto out;
 
-       for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
+       /* Protect inode->i_flock using the BKL */
+       lock_kernel();
+       for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
                if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
                        continue;
                if (nfs_file_open_context(fl->fl_file) != ctx)
                        continue;
+               unlock_kernel();
                status = nfs4_lock_delegation_recall(state, fl);
-               if (status >= 0)
-                       continue;
-               switch (status) {
-                       default:
-                               printk(KERN_ERR "%s: unhandled error %d.\n",
-                                               __FUNCTION__, status);
-                       case -NFS4ERR_EXPIRED:
-                               /* kill_proc(fl->fl_pid, SIGLOST, 1); */
-                       case -NFS4ERR_STALE_CLIENTID:
-                               nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
-                               goto out_err;
-               }
+               if (status < 0)
+                       goto out;
+               lock_kernel();
        }
-       return 0;
-out_err:
+       unlock_kernel();
+out:
        return status;
 }
 
@@ -109,6 +128,7 @@ again:
 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
 {
        struct nfs_delegation *delegation = NFS_I(inode)->delegation;
+       struct rpc_cred *oldcred;
 
        if (delegation == NULL)
                return;
@@ -116,11 +136,54 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, st
                        sizeof(delegation->stateid.data));
        delegation->type = res->delegation_type;
        delegation->maxsize = res->maxsize;
-       put_rpccred(cred);
+       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);
+}
+
+static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
+{
+       int res = 0;
+
+       res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
+       nfs_free_delegation(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_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;
 }
 
 /*
@@ -131,6 +194,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
        struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
        struct nfs_inode *nfsi = NFS_I(inode);
        struct nfs_delegation *delegation;
+       struct nfs_delegation *freeme = NULL;
        int status = 0;
 
        delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
@@ -143,42 +207,49 @@ 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) {
-               list_add_rcu(&delegation->super_list, &clp->cl_delegations);
-               nfsi->delegation_state = delegation->type;
-               rcu_assign_pointer(nfsi->delegation, delegation);
-               delegation = NULL;
-       } else {
+       if (rcu_dereference(nfsi->delegation) != NULL) {
                if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
-                                       sizeof(delegation->stateid)) != 0 ||
-                               delegation->type != nfsi->delegation->type) {
-                       printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
-                                       __FUNCTION__, NIPQUAD(clp->cl_addr.sin_addr));
-                       status = -EIO;
+                                       sizeof(delegation->stateid)) == 0 &&
+                               delegation->type == nfsi->delegation->type) {
+                       goto out;
                }
+               /*
+                * Deal with broken servers that hand out two
+                * delegations for the same file.
+                */
+               dfprintk(FILE, "%s: server %s handed out "
+                               "a duplicate delegation!\n",
+                               __func__, clp->cl_hostname);
+               if (delegation->type <= nfsi->delegation->type) {
+                       freeme = delegation;
+                       delegation = NULL;
+                       goto out;
+               }
+               freeme = nfs_detach_delegation_locked(nfsi, NULL);
        }
+       list_add_rcu(&delegation->super_list, &clp->cl_delegations);
+       nfsi->delegation_state = delegation->type;
+       rcu_assign_pointer(nfsi->delegation, delegation);
+       delegation = NULL;
 
        /* Ensure we revalidate the attributes and page cache! */
        spin_lock(&inode->i_lock);
        nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
        spin_unlock(&inode->i_lock);
 
+out:
        spin_unlock(&clp->cl_lock);
-       kfree(delegation);
+       if (delegation != NULL)
+               nfs_free_delegation(delegation);
+       if (freeme != NULL)
+               nfs_do_return_delegation(inode, freeme, 0);
        return status;
 }
 
-static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
-{
-       int res = 0;
-
-       res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
-       nfs_free_delegation(delegation);
-       return res;
-}
-
 /* Sync all data to disk upon delegation return */
 static void nfs_msync_inode(struct inode *inode)
 {
@@ -192,36 +263,68 @@ 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 */
+       /*
+        * Guard against new delegated open/lock/unlock calls and against
+        * state recovery
+        */
        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);
+       return nfs_do_return_delegation(inode, delegation, 1);
 }
 
-static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
+/*
+ * Return all delegations that have been marked for return
+ */
+void nfs_client_return_marked_delegations(struct nfs_client *clp)
 {
-       struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
+       struct nfs_delegation *delegation;
+       struct inode *inode;
 
-       if (delegation == NULL)
-               goto nomatch;
-       if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
-                               sizeof(delegation->stateid.data)) != 0)
-               goto nomatch;
-       list_del_rcu(&delegation->super_list);
-       nfsi->delegation_state = 0;
-       rcu_assign_pointer(nfsi->delegation, NULL);
-       return delegation;
-nomatch:
-       return NULL;
+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
+ * nfs4_clear_inode()
+ */
+void nfs_inode_return_delegation_noreclaim(struct inode *inode)
+{
+       struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+       struct nfs_inode *nfsi = NFS_I(inode);
+       struct nfs_delegation *delegation;
+
+       if (rcu_dereference(nfsi->delegation) != NULL) {
+               spin_lock(&clp->cl_lock);
+               delegation = nfs_detach_delegation_locked(nfsi, NULL);
+               spin_unlock(&clp->cl_lock);
+               if (delegation != NULL)
+                       nfs_do_return_delegation(inode, delegation, 0);
+       }
 }
 
 int nfs_inode_return_delegation(struct inode *inode)
@@ -241,82 +344,55 @@ 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,
-                       "%u.%u.%u.%u-delegreturn",
-                       NIPQUAD(clp->cl_addr.sin_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);
 }
 
 /*
@@ -324,68 +400,29 @@ 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);
-       iput(inode);
-       module_put_and_exit(0);
+       nfs_client_mark_return_unreferenced_delegations(clp);
+       nfs_delegation_run_state_manager(clp);
 }
 
 /*
@@ -393,22 +430,20 @@ 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;
-
-       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;
+       struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+       struct nfs_delegation *delegation;
+
+       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;
 }
 
 /*
@@ -420,10 +455,14 @@ 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;
@@ -437,7 +476,7 @@ 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();
 }
 
@@ -447,17 +486,22 @@ 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();