Commit aee7af35 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Fix problems with close in the presence of a delegation 



In the presence of delegations, we can no longer assume that the
state->n_rdwr, state->n_rdonly, state->n_wronly reflect the open
stateid share mode, and so we need to calculate the initial value
for calldata->arg.fmode using the state->flags.

Reported-by: default avatarJames Drews <drews@engr.wisc.edu>
Fixes: 88069f77 (NFSv41: Fix a potential state leakage when...)
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 52addcf9

fs/nfs/nfs4proc.c

+12 −5
Original line number Diff line number Diff line
@@ -2601,6 +2601,7 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) 
	struct nfs4_closedata *calldata = data;

	struct nfs4_state *state = calldata->state;

	struct inode *inode = calldata->inode;

	bool is_rdonly, is_wronly, is_rdwr;

	int call_close = 0;



	dprintk("%s: begin!\n", __func__);
@@ -2608,18 +2609,24 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) 
		goto out_wait;



	task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE];

	calldata->arg.fmode = FMODE_READ|FMODE_WRITE;

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

	is_rdwr = test_bit(NFS_O_RDWR_STATE, &state->flags);

	is_rdonly = test_bit(NFS_O_RDONLY_STATE, &state->flags);

	is_wronly = test_bit(NFS_O_WRONLY_STATE, &state->flags);

	/* Calculate the current open share mode */

	calldata->arg.fmode = 0;

	if (is_rdonly || is_rdwr)

		calldata->arg.fmode |= FMODE_READ;

	if (is_wronly || is_rdwr)

		calldata->arg.fmode |= FMODE_WRITE;

	/* Calculate the change in open mode */

	if (state->n_rdwr == 0) {

		if (state->n_rdonly == 0) {

			call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);

			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);

			call_close |= is_rdonly || is_rdwr;

			calldata->arg.fmode &= ~FMODE_READ;

		}

		if (state->n_wronly == 0) {

			call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);

			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);

			call_close |= is_wronly || is_rdwr;

			calldata->arg.fmode &= ~FMODE_WRITE;

		}

	}

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