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: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 5ef4c57..41a5f1a 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -349,14 +349,9 @@
{
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 @@
/* 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)
- newstate &= ~FMODE_READ;
- if (state->nwriters == 0)
- newstate &= ~FMODE_WRITE;
+ if (state->n_rdwr == 0) {
+ if (state->n_rdonly == 0)
+ newstate &= ~FMODE_READ;
+ 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;
