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/nfs4proc.c b/fs/nfs/nfs4proc.c
index 8154f25..e494cc2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -297,6 +297,20 @@
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 @@
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 @@
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 @@
spin_lock(&state->owner->so_lock);
spin_lock(&calldata->inode->i_lock);
mode = old_mode = state->state;
- if (state->nreaders == 0)
- mode &= ~FMODE_READ;
- if (state->nwriters == 0)
- mode &= ~FMODE_WRITE;
+ if (state->n_rdwr == 0) {
+ if (state->n_rdonly == 0)
+ mode &= ~FMODE_READ;
+ 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);