NFSv4: Always use the delegation if we have one

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

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 44b56c9..4a1c4d8 100644 (file)
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -122,7 +122,10 @@ struct nfs4_lock_state {
 /* bits for nfs4_state->flags */
 enum {
        LK_STATE_IN_USE,
-       NFS_DELEGATED_STATE,
+       NFS_DELEGATED_STATE,            /* Current stateid is delegation */
+       NFS_O_RDONLY_STATE,             /* OPEN stateid has read-only state */
+       NFS_O_WRONLY_STATE,             /* OPEN stateid has write-only state */
+       NFS_O_RDWR_STATE,               /* OPEN stateid has read/write state */
 };
 
 struct nfs4_state {
@@ -136,11 +139,12 @@ struct nfs4_state {
        unsigned long flags;            /* Do we hold any locks? */
        spinlock_t state_lock;          /* Protects the lock_states list */
 
-       nfs4_stateid stateid;
+       nfs4_stateid stateid;           /* Current stateid: may be delegation */
+       nfs4_stateid open_stateid;      /* OPEN stateid */
 
-       unsigned int n_rdonly;
-       unsigned int n_wronly;
-       unsigned int n_rdwr;
+       unsigned int n_rdonly;          /* Number of read-only references */
+       unsigned int n_wronly;          /* Number of write-only references */
+       unsigned int n_rdwr;            /* Number of read/write references */
        int state;                      /* State on the server (R,W, or RW) */
        atomic_t count;
 };

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 61ba32a..128fe23 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -319,7 +319,7 @@ static int nfs4_wait_for_completion_rpc_task(struct rpc_task *task)
        return ret;
 }
 
-static inline void update_open_stateflags(struct nfs4_state *state, mode_t open_flags)
+static void update_open_stateflags(struct nfs4_state *state, mode_t open_flags)
 {
        switch (open_flags) {
                case FMODE_WRITE:
@@ -331,9 +331,36 @@ static inline void update_open_stateflags(struct nfs4_state *state, mode_t open_
                case FMODE_READ|FMODE_WRITE:
                        state->n_rdwr++;
        }
+       nfs4_state_set_mode_locked(state, state->state | open_flags);
+}
+
+static void nfs_set_open_stateid_locked(struct nfs4_state *state, nfs4_stateid *stateid, int open_flags)
+{
+       if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
+               memcpy(state->stateid.data, stateid->data, sizeof(state->stateid.data));
+       memcpy(state->open_stateid.data, stateid->data, sizeof(state->open_stateid.data));
+       switch (open_flags) {
+               case FMODE_READ:
+                       set_bit(NFS_O_RDONLY_STATE, &state->flags);
+                       break;
+               case FMODE_WRITE:
+                       set_bit(NFS_O_WRONLY_STATE, &state->flags);
+                       break;
+               case FMODE_READ|FMODE_WRITE:
+                       set_bit(NFS_O_RDWR_STATE, &state->flags);
+       }
 }
 
-static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, int open_flags)
+static void nfs_set_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, int open_flags)
+{
+       spin_lock(&state->owner->so_lock);
+       spin_lock(&state->inode->i_lock);
+       nfs_set_open_stateid_locked(state, stateid, open_flags);
+       spin_unlock(&state->inode->i_lock);
+       spin_unlock(&state->owner->so_lock);
+}
+
+static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stateid, nfs4_stateid *deleg_stateid, int open_flags)
 {
        struct inode *inode = state->inode;
 
@@ -341,9 +368,13 @@ static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid,
        /* Protect against nfs4_find_state_byowner() */
        spin_lock(&state->owner->so_lock);
        spin_lock(&inode->i_lock);
-       memcpy(&state->stateid, stateid, sizeof(state->stateid));
+       if (deleg_stateid != NULL) {
+               memcpy(state->stateid.data, deleg_stateid->data, sizeof(state->stateid.data));
+               set_bit(NFS_DELEGATED_STATE, &state->flags);
+       }
+       if (open_stateid != NULL)
+               nfs_set_open_stateid_locked(state, open_stateid, open_flags);
        update_open_stateflags(state, open_flags);
-       nfs4_state_set_mode_locked(state, state->state | open_flags);
        spin_unlock(&inode->i_lock);
        spin_unlock(&state->owner->so_lock);
 }
@@ -352,6 +383,8 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
 {
        struct inode *inode;
        struct nfs4_state *state = NULL;
+       struct nfs_delegation *delegation;
+       nfs4_stateid *deleg_stateid = NULL;
 
        if (!(data->f_attr.valid & NFS_ATTR_FATTR))
                goto out;
@@ -361,13 +394,14 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
        state = nfs4_get_open_state(inode, data->owner);
        if (state == NULL)
                goto put_inode;
-       update_open_stateid(state, &data->o_res.stateid, data->o_arg.open_flags);
        if (data->o_res.delegation_type != 0) {
-               struct nfs_inode *nfsi = NFS_I(inode);
                int delegation_flags = 0;
 
-               if (nfsi->delegation)
-                       delegation_flags = nfsi->delegation->flags;
+               rcu_read_lock();
+               delegation = rcu_dereference(NFS_I(inode)->delegation);
+               if (delegation)
+                       delegation_flags = delegation->flags;
+               rcu_read_unlock();
                if (!(delegation_flags & NFS_DELEGATION_NEED_RECLAIM))
                        nfs_inode_set_delegation(state->inode,
                                        data->owner->so_cred,
@@ -377,6 +411,12 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
                                        data->owner->so_cred,
                                        &data->o_res);
        }
+       rcu_read_lock();
+       delegation = rcu_dereference(NFS_I(inode)->delegation);
+       if (delegation != NULL)
+               deleg_stateid = &delegation->stateid;
+       update_open_stateid(state, &data->o_res.stateid, deleg_stateid, data->o_arg.open_flags);
+       rcu_read_unlock();
 put_inode:
        iput(inode);
 out:
@@ -911,8 +951,7 @@ static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred
        unlock_kernel();
        if (err != 0)
                goto out_put_open_state;
-       set_bit(NFS_DELEGATED_STATE, &state->flags);
-       update_open_stateid(state, &delegation->stateid, open_flags);
+       update_open_stateid(state, NULL, &delegation->stateid, open_flags);
 out_ok:
        nfs4_put_state_owner(sp);
        up_read(&nfsi->rwsem);
@@ -1149,8 +1188,7 @@ static void nfs4_close_done(struct rpc_task *task, void *data)
        nfs_increment_open_seqid(task->tk_status, calldata->arg.seqid);
        switch (task->tk_status) {
                case 0:
-                       memcpy(&state->stateid, &calldata->res.stateid,
-                                       sizeof(state->stateid));
+                       nfs_set_open_stateid(state, &calldata->res.stateid, calldata->arg.open_flags);
                        renew_lease(server, calldata->timestamp);
                        break;
                case -NFS4ERR_STALE_STATEID:
@@ -1175,26 +1213,32 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data)
                .rpc_resp = &calldata->res,
                .rpc_cred = state->owner->so_cred,
        };
-       int mode = 0, old_mode;
+       int clear_rd, clear_wr, clear_rdwr;
+       int mode;
 
        if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0)
                return;
-       /* Recalculate the new open mode in case someone reopened the file
-        * while we were waiting in line to be scheduled.
-        */
+
+       mode = FMODE_READ|FMODE_WRITE;
+       clear_rd = clear_wr = clear_rdwr = 0;
        spin_lock(&state->owner->so_lock);
        spin_lock(&calldata->inode->i_lock);
-       mode = old_mode = state->state;
+       /* Calculate the change in open mode */
        if (state->n_rdwr == 0) {
-               if (state->n_rdonly == 0)
+               if (state->n_rdonly == 0) {
                        mode &= ~FMODE_READ;
-               if (state->n_wronly == 0)
+                       clear_rd |= test_and_clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+                       clear_rdwr |= test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags);
+               }
+               if (state->n_wronly == 0) {
                        mode &= ~FMODE_WRITE;
+                       clear_wr |= test_and_clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+                       clear_rdwr |= test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags);
+               }
        }
-       nfs4_state_set_mode_locked(state, mode);
        spin_unlock(&calldata->inode->i_lock);
        spin_unlock(&state->owner->so_lock);
-       if (mode == old_mode || test_bit(NFS_DELEGATED_STATE, &state->flags)) {
+       if (!clear_rd && !clear_wr && !clear_rdwr) {
                /* Note: exit _without_ calling nfs4_close_done */
                task->tk_action = NULL;
                return;
@@ -1238,7 +1282,7 @@ int nfs4_do_close(struct path *path, struct nfs4_state *state)
        calldata->inode = state->inode;
        calldata->state = state;
        calldata->arg.fh = NFS_FH(state->inode);
-       calldata->arg.stateid = &state->stateid;
+       calldata->arg.stateid = &state->open_stateid;
        /* Serialization for the sequence id */
        calldata->arg.seqid = nfs_alloc_seqid(&state->owner->so_seqid);
        if (calldata->arg.seqid == NULL)

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index ac816b3..4f78c0d 100644 (file)
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -412,7 +412,8 @@ void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
 {
        struct inode *inode = state->inode;
        struct nfs4_state_owner *owner = state->owner;
-       int oldstate, newstate = 0;
+       int call_close = 0;
+       int newstate;
 
        atomic_inc(&owner->so_count);
        /* Protect against nfs4_find_state() */
@@ -428,21 +429,26 @@ void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
                case FMODE_READ|FMODE_WRITE:
                        state->n_rdwr--;
        }
-       oldstate = newstate = state->state;
+       newstate = FMODE_READ|FMODE_WRITE;
        if (state->n_rdwr == 0) {
-               if (state->n_rdonly == 0)
+               if (state->n_rdonly == 0) {
                        newstate &= ~FMODE_READ;
-               if (state->n_wronly == 0)
+                       call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
+                       call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
+               }
+               if (state->n_wronly == 0) {
                        newstate &= ~FMODE_WRITE;
+                       call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
+                       call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
+               }
+               if (newstate == 0)
+                       clear_bit(NFS_DELEGATED_STATE, &state->flags);
        }
-       if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
-               nfs4_state_set_mode_locked(state, newstate);
-               oldstate = newstate;
-       }
+       nfs4_state_set_mode_locked(state, newstate);
        spin_unlock(&inode->i_lock);
        spin_unlock(&owner->so_lock);
 
-       if (oldstate == newstate) {
+       if (!call_close) {
                nfs4_put_open_state(state);
                nfs4_put_state_owner(owner);
        } else
@@ -838,6 +844,10 @@ static void nfs4_state_mark_reclaim(struct nfs_client *clp)
                sp->so_seqid.flags = 0;
                spin_lock(&sp->so_lock);
                list_for_each_entry(state, &sp->so_states, open_states) {
+                       clear_bit(NFS_DELEGATED_STATE, &state->flags);
+                       clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+                       clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+                       clear_bit(NFS_O_RDWR_STATE, &state->flags);
                        list_for_each_entry(lock, &state->lock_states, ls_locks) {
                                lock->ls_seqid.counter = 0;
                                lock->ls_seqid.flags = 0;