Commit e7616923 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Make nfs4_state track O_RDWR, O_RDONLY and O_WRONLY separately 



 A closer reading of RFC3530 reveals that OPEN_DOWNGRADE must always
 specify a access modes that have been the argument of a previous OPEN
 operation.
 IOW: doing OPEN(O_RDWR) and then OPEN_DOWNGRADE(O_WRONLY) is forbidden
 unless the user called OPEN(O_WRONLY)

 In order to fix that, we really need to track the three possible open
 states separately.

 Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent cdd4e68b

fs/nfs/nfs4_fs.h

+3 −2
Original line number Diff line number Diff line
@@ -182,8 +182,9 @@ struct nfs4_state { 


	nfs4_stateid stateid;



	unsigned int nreaders;

	unsigned int nwriters;

	unsigned int n_rdonly;

	unsigned int n_wronly;

	unsigned int n_rdwr;

	int state;			/* State on the server (R,W, or RW) */

	atomic_t count;

};

fs/nfs/nfs4proc.c

+22 −12
Original line number Diff line number Diff line
@@ -297,6 +297,20 @@ 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)

{

	switch (open_flags) {

		case FMODE_WRITE:

			state->n_wronly++;

			break;

		case FMODE_READ:

			state->n_rdonly++;

			break;

		case FMODE_READ|FMODE_WRITE:

			state->n_rdwr++;

	}

}



static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, int open_flags)

{

	struct inode *inode = state->inode;
@@ -306,10 +320,7 @@ static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *stateid, 
	spin_lock(&state->owner->so_lock);

	spin_lock(&inode->i_lock);

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

	if ((open_flags & FMODE_WRITE))

		state->nwriters++;

	if (open_flags & FMODE_READ)

		state->nreaders++;

	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);
@@ -822,10 +833,7 @@ static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred 
	err = -ENOENT;

	if ((state->state & open_flags) == open_flags) {

		spin_lock(&inode->i_lock);

		if (open_flags & FMODE_READ)

			state->nreaders++;

		if (open_flags & FMODE_WRITE)

			state->nwriters++;

		update_open_stateflags(state, open_flags);

		spin_unlock(&inode->i_lock);

		goto out_ok;

	} else if (state->state != 0)
@@ -1082,10 +1090,12 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) 
	spin_lock(&state->owner->so_lock);

	spin_lock(&calldata->inode->i_lock);

	mode = old_mode = state->state;

	if (state->nreaders == 0)

	if (state->n_rdwr == 0) {

		if (state->n_rdonly == 0)

			mode &= ~FMODE_READ;

	if (state->nwriters == 0)

		if (state->n_wronly == 0)

			mode &= ~FMODE_WRITE;

	}

	nfs4_state_set_mode_locked(state, mode);

	spin_unlock(&calldata->inode->i_lock);

	spin_unlock(&state->owner->so_lock);

fs/nfs/nfs4state.c

+17 −14
Original line number Diff line number Diff line
@@ -349,14 +349,9 @@ nfs4_alloc_open_state(void) 
{

	struct nfs4_state *state;



	state = kmalloc(sizeof(*state), GFP_KERNEL);

	state = kzalloc(sizeof(*state), GFP_KERNEL);

	if (!state)

		return NULL;

	state->state = 0;

	state->nreaders = 0;

	state->nwriters = 0;

	state->flags = 0;

	memset(state->stateid.data, 0, sizeof(state->stateid.data));

	atomic_set(&state->count, 1);

	INIT_LIST_HEAD(&state->lock_states);

	spin_lock_init(&state->state_lock);
@@ -475,15 +470,23 @@ void nfs4_close_state(struct nfs4_state *state, mode_t mode) 
	/* Protect against nfs4_find_state() */

	spin_lock(&owner->so_lock);

	spin_lock(&inode->i_lock);

	if (mode & FMODE_READ)

		state->nreaders--;

	if (mode & FMODE_WRITE)

		state->nwriters--;

	switch (mode & (FMODE_READ | FMODE_WRITE)) {

		case FMODE_READ:

			state->n_rdonly--;

			break;

		case FMODE_WRITE:

			state->n_wronly--;

			break;

		case FMODE_READ|FMODE_WRITE:

			state->n_rdwr--;

	}

	oldstate = newstate = state->state;

	if (state->nreaders == 0)

	if (state->n_rdwr == 0) {

		if (state->n_rdonly == 0)

			newstate &= ~FMODE_READ;

	if (state->nwriters == 0)

		if (state->n_wronly == 0)

			newstate &= ~FMODE_WRITE;

	}

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

		nfs4_state_set_mode_locked(state, newstate);

		oldstate = newstate;

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