Thanks, Trond! I applied this patch on 4.19rc4 and ran my test, and
this seemed to have solved the problem!
On Fri, Sep 28, 2018 at 1:03 PM Trond Myklebust <trondmy@xxxxxxxxx> wrote:
>
> We need to ensure that inode and dentry revalidation occurs correctly
> on reopen of a file that is already open. Currently, we can end up
> not revalidating either in the case of NFSv4.0, due to the 'cached open'
> path.
> Let's fix that by ensuring that we only do cached open for the special
> cases of open recovery and delegation return.
>
> Reported-by: Stan Hu <stanhu@xxxxxxxxx>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> ---
> fs/nfs/nfs4proc.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 4da59bd53f98..db84b4adbc49 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -1349,12 +1349,20 @@ static bool nfs4_mode_match_open_stateid(struct nfs4_state *state,
> return false;
> }
>
> -static int can_open_cached(struct nfs4_state *state, fmode_t mode, int open_mode)
> +static int can_open_cached(struct nfs4_state *state, fmode_t mode,
> + int open_mode, enum open_claim_type4 claim)
> {
> int ret = 0;
>
> if (open_mode & (O_EXCL|O_TRUNC))
> goto out;
> + switch (claim) {
> + case NFS4_OPEN_CLAIM_NULL:
> + case NFS4_OPEN_CLAIM_FH:
> + goto out;
> + default:
> + break;
> + }
> switch (mode & (FMODE_READ|FMODE_WRITE)) {
> case FMODE_READ:
> ret |= test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0
> @@ -1747,7 +1755,7 @@ static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
>
> for (;;) {
> spin_lock(&state->owner->so_lock);
> - if (can_open_cached(state, fmode, open_mode)) {
> + if (can_open_cached(state, fmode, open_mode, claim)) {
> update_open_stateflags(state, fmode);
> spin_unlock(&state->owner->so_lock);
> goto out_return_state;
> @@ -2294,7 +2302,8 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
> if (data->state != NULL) {
> struct nfs_delegation *delegation;
>
> - if (can_open_cached(data->state, data->o_arg.fmode, data->o_arg.open_flags))
> + if (can_open_cached(data->state, data->o_arg.fmode,
> + data->o_arg.open_flags, claim))
> goto out_no_action;
> rcu_read_lock();
> delegation = rcu_dereference(NFS_I(data->state->inode)->delegation);
> --
> 2.17.1
>
