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

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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: James Drews <drews@engr.wisc.edu>
Fixes: 88069f77e1 (NFSv41: Fix a potential state leakage when...)
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2014-08-25 22:33:12 -04:00
commit aee7af356e
1 changed files with 12 additions and 5 deletions
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17
fs/nfs/nfs4proc.c
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@ -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;
}
}