Commit 8d0a8a9d authored by Trond Myklebust's avatar Trond Myklebust
Browse files

[PATCH] NFSv4: Clean up nfs4 lock state accounting 



 Ensure that lock owner structures are not released prematurely.

 Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent ecdbf769

fs/nfs/nfs4_fs.h

+3 −6
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ struct nfs4_state_owner { 


struct nfs4_lock_state {

	struct list_head	ls_locks;	/* Other lock stateids */

	struct nfs4_state *	ls_state;	/* Pointer to open state */

	fl_owner_t		ls_owner;	/* POSIX lock owner */

#define NFS_LOCK_INITIALIZED 1

	int			ls_flags;
@@ -153,7 +154,7 @@ struct nfs4_state { 


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

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

	rwlock_t state_lock;		/* Protects the lock_states list */

	spinlock_t state_lock;		/* Protects the lock_states list */



	nfs4_stateid stateid;
@@ -225,12 +226,8 @@ extern void nfs4_close_state(struct nfs4_state *, mode_t); 
extern struct nfs4_state *nfs4_find_state(struct inode *, struct rpc_cred *, mode_t mode);

extern void nfs4_increment_seqid(int status, struct nfs4_state_owner *sp);

extern void nfs4_schedule_state_recovery(struct nfs4_client *);

extern struct nfs4_lock_state *nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t);

extern struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t);

extern void nfs4_put_lock_state(struct nfs4_lock_state *state);

extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);

extern void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *ls);

extern void nfs4_notify_setlk(struct nfs4_state *, struct file_lock *, struct nfs4_lock_state *);

extern void nfs4_notify_unlck(struct nfs4_state *, struct file_lock *, struct nfs4_lock_state *);

extern void nfs4_copy_stateid(nfs4_stateid *, struct nfs4_state *, fl_owner_t);



extern const nfs4_stateid zero_stateid;

fs/nfs/nfs4proc.c

+30 −39
Original line number Diff line number Diff line
@@ -2626,14 +2626,11 @@ 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);

	lsp = nfs4_find_lock_state(state, request->fl_owner);

	if (lsp)

	status = nfs4_set_lock_state(state, request);

	if (status != 0)

		goto out;

	lsp = request->fl_u.nfs4_fl.owner;

	nlo.id = lsp->ls_id; 

	else {

		spin_lock(&clp->cl_lock);

		nlo.id = nfs4_alloc_lockowner_id(clp);

		spin_unlock(&clp->cl_lock);

	}

	arg.u.lockt = &nlo;

	status = rpc_call_sync(server->client, &msg, 0);

	if (!status) {
@@ -2654,8 +2651,7 @@ static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock 
		request->fl_pid = 0;

		status = 0;

	}

	if (lsp)

		nfs4_put_lock_state(lsp);

out:

	up(&state->lock_sema);

	up_read(&clp->cl_sem);

	return status;
@@ -2715,28 +2711,26 @@ static int _nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock 
	};

	struct nfs4_lock_state *lsp;

	struct nfs_locku_opargs luargs;

	int status = 0;

	int status;

			

	down_read(&clp->cl_sem);

	down(&state->lock_sema);

	lsp = nfs4_find_lock_state(state, request->fl_owner);

	if (!lsp)

	status = nfs4_set_lock_state(state, request);

	if (status != 0)

		goto out;

	lsp = request->fl_u.nfs4_fl.owner;

	/* We might have lost the locks! */

	if ((lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0) {

	if ((lsp->ls_flags & NFS_LOCK_INITIALIZED) == 0)

		goto out;

	luargs.seqid = lsp->ls_seqid;

	memcpy(&luargs.stateid, &lsp->ls_stateid, sizeof(luargs.stateid));

	arg.u.locku = &luargs;

	status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);

	nfs4_increment_lock_seqid(status, lsp);

	}



	if (status == 0) {

	if (status == 0)

		memcpy(&lsp->ls_stateid,  &res.u.stateid, 

				sizeof(lsp->ls_stateid));

		nfs4_notify_unlck(state, request, lsp);

	}

	nfs4_put_lock_state(lsp);

out:

	up(&state->lock_sema);

	if (status == 0)
@@ -2762,7 +2756,7 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *r 
{

	struct inode *inode = state->inode;

	struct nfs_server *server = NFS_SERVER(inode);

	struct nfs4_lock_state *lsp;

	struct nfs4_lock_state *lsp = request->fl_u.nfs4_fl.owner;

	struct nfs_lockargs arg = {

		.fh = NFS_FH(inode),

		.type = nfs4_lck_type(cmd, request),
@@ -2784,9 +2778,6 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *r 
	};

	int status;



	lsp = nfs4_get_lock_state(state, request->fl_owner);

	if (lsp == NULL)

		return -ENOMEM;

	if (!(lsp->ls_flags & NFS_LOCK_INITIALIZED)) {

		struct nfs4_state_owner *owner = state->owner;

		struct nfs_open_to_lock otl = {
@@ -2808,27 +2799,26 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *r 
		* seqid mutating errors */

		nfs4_increment_seqid(status, owner);

		up(&owner->so_sema);

		if (status == 0) {

			lsp->ls_flags |= NFS_LOCK_INITIALIZED;

			lsp->ls_seqid++;

		}

	} else {

		struct nfs_exist_lock el = {

			.seqid = lsp->ls_seqid,

		};

		memcpy(&el.stateid, &lsp->ls_stateid, sizeof(el.stateid));

		largs.u.exist_lock = &el;

		largs.new_lock_owner = 0;

		arg.u.lock = &largs;

		status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);

	}

		/* increment seqid on success, and * seqid mutating errors*/

		nfs4_increment_lock_seqid(status, lsp);

	}

	/* save the returned stateid. */

	if (status == 0) {

	if (status == 0)

		memcpy(&lsp->ls_stateid, &res.u.stateid, sizeof(nfs4_stateid));

		lsp->ls_flags |= NFS_LOCK_INITIALIZED;

		if (!reclaim)

			nfs4_notify_setlk(state, request, lsp);

	} else if (status == -NFS4ERR_DENIED)

	else if (status == -NFS4ERR_DENIED)

		status = -EAGAIN;

	nfs4_put_lock_state(lsp);

	return status;

}
@@ -2869,6 +2859,8 @@ static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock 


	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) {
@@ -2927,7 +2919,6 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request) 
		if (signalled())

			break;

	} while(status < 0);



	return status;

}

fs/nfs/nfs4state.c

+79 −99
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ nfs4_alloc_open_state(void) 
	atomic_set(&state->count, 1);

	INIT_LIST_HEAD(&state->lock_states);

	init_MUTEX(&state->lock_sema);

	rwlock_init(&state->state_lock);

	spin_lock_init(&state->state_lock);

	return state;

}
@@ -542,16 +542,6 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner) 
	return NULL;

}



struct nfs4_lock_state *

nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)

{

	struct nfs4_lock_state *lsp;

	read_lock(&state->state_lock);

	lsp = __nfs4_find_lock_state(state, fl_owner);

	read_unlock(&state->state_lock);

	return lsp;

}



/*

 * Return a compatible lock_state. If no initialized lock_state structure

 * exists, return an uninitialized one.
@@ -568,14 +558,13 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f 
		return NULL;

	lsp->ls_flags = 0;

	lsp->ls_seqid = 0;	/* arbitrary */

	lsp->ls_id = -1; 

	memset(lsp->ls_stateid.data, 0, sizeof(lsp->ls_stateid.data));

	atomic_set(&lsp->ls_count, 1);

	lsp->ls_owner = fl_owner;

	INIT_LIST_HEAD(&lsp->ls_locks);

	spin_lock(&clp->cl_lock);

	lsp->ls_id = nfs4_alloc_lockowner_id(clp);

	spin_unlock(&clp->cl_lock);

	INIT_LIST_HEAD(&lsp->ls_locks);

	return lsp;

}
@@ -585,121 +574,112 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f 
 *

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

 */

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

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

{

	struct nfs4_lock_state * lsp;

	struct nfs4_lock_state *lsp, *new = NULL;

	

	lsp = nfs4_find_lock_state(state, owner);

	if (lsp == NULL)

		lsp = nfs4_alloc_lock_state(state, owner);

	for(;;) {

		spin_lock(&state->state_lock);

		lsp = __nfs4_find_lock_state(state, owner);

		if (lsp != NULL)

			break;

		if (new != NULL) {

			new->ls_state = state;

			list_add(&new->ls_locks, &state->lock_states);

			set_bit(LK_STATE_IN_USE, &state->flags);

			lsp = new;

			new = NULL;

			break;

		}

		spin_unlock(&state->state_lock);

		new = nfs4_alloc_lock_state(state, owner);

		if (new == NULL)

			return NULL;

	}

	spin_unlock(&state->state_lock);

	kfree(new);

	return lsp;

}



/*

 * Byte-range lock aware utility to initialize the stateid of read/write

 * requests.

 * Release reference to lock_state, and free it if we see that

 * it is no longer in use

 */

void

nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)

static void nfs4_put_lock_state(struct nfs4_lock_state *lsp)

{

	if (test_bit(LK_STATE_IN_USE, &state->flags)) {

		struct nfs4_lock_state *lsp;

	struct nfs4_state *state;



		lsp = nfs4_find_lock_state(state, fl_owner);

		if (lsp) {

			memcpy(dst, &lsp->ls_stateid, sizeof(*dst));

			nfs4_put_lock_state(lsp);

	if (lsp == NULL)

		return;

		}

	}

	memcpy(dst, &state->stateid, sizeof(*dst));

	state = lsp->ls_state;

	if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))

		return;

	list_del(&lsp->ls_locks);

	if (list_empty(&state->lock_states))

		clear_bit(LK_STATE_IN_USE, &state->flags);

	spin_unlock(&state->state_lock);

	kfree(lsp);

}



/*

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

*/

void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *lsp)

static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)

{

	if (status == NFS_OK || seqid_mutating_err(-status))

		lsp->ls_seqid++;

}

	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;



/* 

* Check to see if the request lock (type FL_UNLK) effects the fl lock.

*

* fl and request must have the same posix owner

*

* return: 

* 0 -> fl not effected by request

* 1 -> fl consumed by request

*/

	dst->fl_u.nfs4_fl.owner = lsp;

	atomic_inc(&lsp->ls_count);

}



static int

nfs4_check_unlock(struct file_lock *fl, struct file_lock *request)

static void nfs4_fl_release_lock(struct file_lock *fl)

{

	if (fl->fl_start >= request->fl_start && fl->fl_end <= request->fl_end)

		return 1;

	return 0;

	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);

}



/*

 * Post an initialized lock_state on the state->lock_states list.

 */

void nfs4_notify_setlk(struct nfs4_state *state, struct file_lock *request, struct nfs4_lock_state *lsp)

static struct file_lock_operations nfs4_fl_lock_ops = {

	.fl_copy_lock = nfs4_fl_copy_lock,

	.fl_release_private = nfs4_fl_release_lock,

};



int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)

{

	if (!list_empty(&lsp->ls_locks))

		return;

	atomic_inc(&lsp->ls_count);

	write_lock(&state->state_lock);

	list_add(&lsp->ls_locks, &state->lock_states);

	set_bit(LK_STATE_IN_USE, &state->flags);

	write_unlock(&state->state_lock);

	struct nfs4_lock_state *lsp;



	if (fl->fl_ops != NULL)

		return 0;

	lsp = nfs4_get_lock_state(state, fl->fl_owner);

	if (lsp == NULL)

		return -ENOMEM;

	fl->fl_u.nfs4_fl.owner = lsp;

	fl->fl_ops = &nfs4_fl_lock_ops;

	return 0;

}



/*

 * to decide to 'reap' lock state:

 * 1) search i_flock for file_locks with fl.lock_state = to ls.

 * 2) determine if unlock will consume found lock. 

 * 	if so, reap

 *

 * 	else, don't reap.

 *

 * Byte-range lock aware utility to initialize the stateid of read/write

 * requests.

 */

void

nfs4_notify_unlck(struct nfs4_state *state, struct file_lock *request, struct nfs4_lock_state *lsp)

void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)

{

	struct inode *inode = state->inode;

	struct file_lock *fl;

	struct nfs4_lock_state *lsp;



	for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {

		if (!(fl->fl_flags & FL_POSIX))

			continue;

		if (fl->fl_owner != lsp->ls_owner)

			continue;

		/* Exit if we find at least one lock which is not consumed */

		if (nfs4_check_unlock(fl,request) == 0)

	memcpy(dst, &state->stateid, sizeof(*dst));

	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)

		return;

	}



	write_lock(&state->state_lock);

	list_del_init(&lsp->ls_locks);

	if (list_empty(&state->lock_states))

		clear_bit(LK_STATE_IN_USE, &state->flags);

	write_unlock(&state->state_lock);

	spin_lock(&state->state_lock);

	lsp = __nfs4_find_lock_state(state, fl_owner);

	if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)

		memcpy(dst, &lsp->ls_stateid, sizeof(*dst));

	spin_unlock(&state->state_lock);

	nfs4_put_lock_state(lsp);

}



/*

 * Release reference to lock_state, and free it if we see that

 * it is no longer in use

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

*/

void

nfs4_put_lock_state(struct nfs4_lock_state *lsp)

void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *lsp)

{

	if (!atomic_dec_and_test(&lsp->ls_count))

		return;

	BUG_ON (!list_empty(&lsp->ls_locks));

	kfree(lsp);

	if (status == NFS_OK || seqid_mutating_err(-status))

		lsp->ls_seqid++;

}



/*

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -674,6 +674,7 @@ struct file_lock { 
	struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */

	union {

		struct nfs_lock_info	nfs_fl;

		struct nfs4_lock_info	nfs4_fl;

	} fl_u;

};

include/linux/nfs_fs_i.h

+5 −0
Original line number Diff line number Diff line
@@ -16,6 +16,11 @@ struct nfs_lock_info { 
	struct nlm_lockowner *owner;

};



struct nfs4_lock_state;

struct nfs4_lock_info {

	struct nfs4_lock_state *owner;

};



/*

 * Lock flag values

 */