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Commit e6dfa553 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Remove obsolete state_owner and lock_owner semaphores 



 OPEN, CLOSE, etc no longer need these semaphores to ensure ordering of
 requests.

 Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 9512135d

fs/nfs/nfs4_fs.h

+0 −6
Original line number Diff line number Diff line
@@ -125,16 +125,11 @@ static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status 
 * NFS4 state_owners and lock_owners are simply labels for ordered

 * sequences of RPC calls. Their sole purpose is to provide once-only

 * semantics by allowing the server to identify replayed requests.

 *

 * The ->so_sema is held during all state_owner seqid-mutating operations:

 * OPEN, OPEN_DOWNGRADE, and CLOSE. Its purpose is to properly serialize

 * so_seqid.

 */

struct nfs4_state_owner {

	struct list_head     so_list;	 /* per-clientid list of state_owners */

	struct nfs4_client   *so_client;

	u32                  so_id;      /* 32-bit identifier, unique */

	struct semaphore     so_sema;

	atomic_t	     so_count;



	struct rpc_cred	     *so_cred;	 /* Associated cred */
@@ -183,7 +178,6 @@ struct nfs4_state { 
	struct inode *inode;		/* Pointer to the inode */



	unsigned long flags;		/* Do we hold any locks? */

	struct semaphore lock_sema;	/* Serializes file locking operations */

	spinlock_t state_lock;		/* Protects the lock_states list */



	nfs4_stateid stateid;

fs/nfs/nfs4proc.c

+0 −18
Original line number Diff line number Diff line
@@ -224,7 +224,6 @@ static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, 
/*

 * OPEN_RECLAIM:

 * 	reclaim state on the server after a reboot.

 * 	Assumes caller is holding the sp->so_sem

 */

static int _nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)

{
@@ -322,7 +321,6 @@ static int _nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state 
	};

	int status = 0;



	down(&sp->so_sema);

	if (!test_bit(NFS_DELEGATED_STATE, &state->flags))

		goto out;

	if (state->state == 0)
@@ -342,7 +340,6 @@ static int _nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state 
	}

	nfs_free_seqid(arg.seqid);

out:

	up(&sp->so_sema);

	dput(parent);

	return status;

}
@@ -595,7 +592,6 @@ static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred 
		dprintk("%s: nfs4_get_state_owner failed!\n", __FUNCTION__);

		goto out_err;

	}

	down(&sp->so_sema);

	state = nfs4_get_open_state(inode, sp);

	if (state == NULL)

		goto out_err;
@@ -620,7 +616,6 @@ static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred 
	set_bit(NFS_DELEGATED_STATE, &state->flags);

	update_open_stateid(state, &delegation->stateid, open_flags);

out_ok:

	up(&sp->so_sema);

	nfs4_put_state_owner(sp);

	up_read(&nfsi->rwsem);

	up_read(&clp->cl_sem);
@@ -631,7 +626,6 @@ static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred 
	if (sp != NULL) {

		if (state != NULL)

			nfs4_put_open_state(state);

		up(&sp->so_sema);

		nfs4_put_state_owner(sp);

	}

	up_read(&nfsi->rwsem);
@@ -696,7 +690,6 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st 
	} else

		o_arg.u.attrs = sattr;

	/* Serialization for the sequence id */

	down(&sp->so_sema);



	o_arg.seqid = nfs_alloc_seqid(&sp->so_seqid);

	if (o_arg.seqid == NULL)
@@ -716,7 +709,6 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st 
	if (o_res.delegation_type != 0)

		nfs_inode_set_delegation(inode, cred, &o_res);

	nfs_free_seqid(o_arg.seqid);

	up(&sp->so_sema);

	nfs4_put_state_owner(sp);

	up_read(&clp->cl_sem);

	*res = state;
@@ -726,7 +718,6 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st 
		if (state != NULL)

			nfs4_put_open_state(state);

		nfs_free_seqid(o_arg.seqid);

		up(&sp->so_sema);

		nfs4_put_state_owner(sp);

	}

	/* Note: clp->cl_sem must be released before nfs4_put_open_state()! */
@@ -833,7 +824,6 @@ static void nfs4_free_closedata(struct nfs4_closedata *calldata) 


	nfs4_put_open_state(calldata->state);

	nfs_free_seqid(calldata->arg.seqid);

	up(&sp->so_sema);

	nfs4_put_state_owner(sp);

	up_read(&server->nfs4_state->cl_sem);

	kfree(calldata);
@@ -2702,7 +2692,6 @@ static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock 


	down_read(&clp->cl_sem);

	nlo.clientid = clp->cl_clientid;

	down(&state->lock_sema);

	status = nfs4_set_lock_state(state, request);

	if (status != 0)

		goto out;
@@ -2729,7 +2718,6 @@ static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock 
		status = 0;

	}

out:

	up(&state->lock_sema);

	up_read(&clp->cl_sem);

	return status;

}
@@ -2791,7 +2779,6 @@ static int _nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock 
	int status;

			

	down_read(&clp->cl_sem);

	down(&state->lock_sema);

	status = nfs4_set_lock_state(state, request);

	if (status != 0)

		goto out;
@@ -2813,7 +2800,6 @@ static int _nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock 
				sizeof(lsp->ls_stateid.data));

	nfs_free_seqid(luargs.seqid);

out:

	up(&state->lock_sema);

	if (status == 0)

		do_vfs_lock(request->fl_file, request);

	up_read(&clp->cl_sem);
@@ -2877,7 +2863,6 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *r 
		largs.u.open_lock = &otl;

		largs.new_lock_owner = 1;

		arg.u.lock = &largs;

		down(&owner->so_sema);

		otl.open_seqid = nfs_alloc_seqid(&owner->so_seqid);

		if (otl.open_seqid != NULL) {

			status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
@@ -2885,7 +2870,6 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *r 
			nfs_increment_open_seqid(status, otl.open_seqid);

			nfs_free_seqid(otl.open_seqid);

		}

		up(&owner->so_sema);

		if (status == 0)

			nfs_confirm_seqid(&lsp->ls_seqid, 0);

	} else {
@@ -2944,11 +2928,9 @@ static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock 
	int status;



	down_read(&clp->cl_sem);

	down(&state->lock_sema);

	status = nfs4_set_lock_state(state, request);

	if (status == 0)

		status = _nfs4_do_setlk(state, cmd, request, 0);

	up(&state->lock_sema);

	if (status == 0) {

		/* Note: we always want to sleep here! */

		request->fl_flags |= FL_SLEEP;

fs/nfs/nfs4state.c

+4 −11
Original line number Diff line number Diff line
@@ -267,7 +267,6 @@ nfs4_alloc_state_owner(void) 
	sp = kzalloc(sizeof(*sp),GFP_KERNEL);

	if (!sp)

		return NULL;

	init_MUTEX(&sp->so_sema);

	INIT_LIST_HEAD(&sp->so_states);

	INIT_LIST_HEAD(&sp->so_delegations);

	rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
@@ -362,7 +361,6 @@ nfs4_alloc_open_state(void) 
	memset(state->stateid.data, 0, sizeof(state->stateid.data));

	atomic_set(&state->count, 1);

	INIT_LIST_HEAD(&state->lock_states);

	init_MUTEX(&state->lock_sema);

	spin_lock_init(&state->state_lock);

	return state;

}
@@ -444,7 +442,6 @@ nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner) 
	state = __nfs4_find_state_byowner(inode, owner);

	if (state == NULL && new != NULL) {

		state = new;

		/* Caller *must* be holding owner->so_sem */

		/* Note: The reclaim code dictates that we add stateless

		 * and read-only stateids to the end of the list */

		list_add_tail(&state->open_states, &owner->so_states);
@@ -464,7 +461,7 @@ nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner) 


/*

 * Beware! Caller must be holding exactly one

 * reference to clp->cl_sem and owner->so_sema!

 * reference to clp->cl_sem!

 */

void nfs4_put_open_state(struct nfs4_state *state)

{
@@ -485,7 +482,6 @@ void nfs4_put_open_state(struct nfs4_state *state) 


/*

 * Beware! Caller must be holding no references to clp->cl_sem!

 * of owner->so_sema!

 */

void nfs4_close_state(struct nfs4_state *state, mode_t mode)

{
@@ -496,7 +492,6 @@ void nfs4_close_state(struct nfs4_state *state, mode_t mode) 


	atomic_inc(&owner->so_count);

	down_read(&clp->cl_sem);

	down(&owner->so_sema);

	/* Protect against nfs4_find_state() */

	spin_lock(&inode->i_lock);

	if (mode & FMODE_READ)
@@ -527,7 +522,6 @@ void nfs4_close_state(struct nfs4_state *state, mode_t mode) 
	}

out:

	nfs4_put_open_state(state);

	up(&owner->so_sema);

	nfs4_put_state_owner(owner);

	up_read(&clp->cl_sem);

}
@@ -553,7 +547,6 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner) 
 * Return a compatible lock_state. If no initialized lock_state structure

 * exists, return an uninitialized one.

 *

 * The caller must be holding state->lock_sema

 */

static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)

{
@@ -577,7 +570,7 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f 
 * Return a compatible lock_state. If no initialized lock_state structure

 * exists, return an uninitialized one.

 *

 * The caller must be holding state->lock_sema and clp->cl_sem

 * The caller must be holding clp->cl_sem

 */

static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)

{
@@ -711,7 +704,7 @@ void nfs_free_seqid(struct nfs_seqid *seqid) 
}



/*

 * Called with sp->so_sema and clp->cl_sem held.

 * Called with clp->cl_sem held.

 *

 * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or

 * failed with a seqid incrementing error -
@@ -750,7 +743,7 @@ void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid) 
}



/*

 * Called with ls->lock_sema and clp->cl_sem held.

 * Called with clp->cl_sem held.

 *

 * Increment the seqid if the LOCK/LOCKU succeeded, or

 * failed with a seqid incrementing error -