On Wed, Sep 11, 2019 at 4:56 PM Trond Myklebust <trondmy@xxxxxxxxxxxxxxx> wrote:
>
> Hi Olga
>
> On Wed, 2019-09-11 at 16:13 -0400, Olga Kornievskaia wrote:
> > Hi Trond,
> >
> > This patch is causing me "problem" (can be seen using generic/323).
> > This test creates 100 processes that each want to open the same file,
> > then close it. Each open gets a stateid with an increasing seqid (the
> > last received by the client is stateid seqid=100). With the patch,
> > upon close I see 1st CLOSE use stateid seqid=1 which ends up failing
> > with ERR_OLD_STATEID and retried until stateid seqid=100 (which was
> > the current id). Reverting the patch give back sending the CLOSE with
> > seqid=100. While nothing failing, I don't think the client's behavior
> > is correct.
>
> Does the following work for you?
Yes that fixes the stateid usage.
>
> Cheers
> Trond
>
> 8<---------------------------------------------
> From 859f6c0f468785770c6e87ae4f62294415018e89 Mon Sep 17 00:00:00 2001
> From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> Date: Tue, 3 Sep 2019 17:37:19 -0400
> Subject: [PATCH v2] NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE
>
> If a CLOSE or OPEN_DOWNGRADE operation receives a NFS4ERR_OLD_STATEID
> then bump the seqid before resending. Ensure we only bump the seqid
> by 1.
>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> ---
> fs/nfs/nfs4_fs.h | 2 --
> fs/nfs/nfs4proc.c | 75 ++++++++++++++++++++++++++++++++++++++++++++--
> fs/nfs/nfs4state.c | 16 ----------
> 3 files changed, 72 insertions(+), 21 deletions(-)
>
> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
> index e8f74ed98e42..16b2e5cc3e94 100644
> --- a/fs/nfs/nfs4_fs.h
> +++ b/fs/nfs/nfs4_fs.h
> @@ -491,8 +491,6 @@ extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
> extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
> const struct nfs_lock_context *, nfs4_stateid *,
> const struct cred **);
> -extern bool nfs4_refresh_open_stateid(nfs4_stateid *dst,
> - struct nfs4_state *state);
> extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
> struct nfs4_state *state);
>
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 025dd5efbf34..c14af2c1c6b6 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -3308,6 +3308,75 @@ nfs4_wait_on_layoutreturn(struct inode *inode, struct rpc_task *task)
> return pnfs_wait_on_layoutreturn(inode, task);
> }
>
> +/*
> + * Update the seqid of an open stateid
> + */
> +static void nfs4_sync_open_stateid(nfs4_stateid *dst,
> + struct nfs4_state *state)
> +{
> + __be32 seqid_open;
> + u32 dst_seqid;
> + int seq;
> +
> + for (;;) {
> + if (!nfs4_valid_open_stateid(state))
> + break;
> + seq = read_seqbegin(&state->seqlock);
> + if (!nfs4_state_match_open_stateid_other(state, dst)) {
> + nfs4_stateid_copy(dst, &state->open_stateid);
> + if (read_seqretry(&state->seqlock, seq))
> + continue;
> + break;
> + }
> + seqid_open = state->open_stateid.seqid;
> + if (read_seqretry(&state->seqlock, seq))
> + continue;
> +
> + dst_seqid = be32_to_cpu(dst->seqid);
> + if ((s32)(dst_seqid - be32_to_cpu(seqid_open)) < 0)
> + dst->seqid = seqid_open;
> + break;
> + }
> +}
> +
> +/*
> + * Update the seqid of an open stateid after receiving
> + * NFS4ERR_OLD_STATEID
> + */
> +static bool nfs4_refresh_open_old_stateid(nfs4_stateid *dst,
> + struct nfs4_state *state)
> +{
> + __be32 seqid_open;
> + u32 dst_seqid;
> + bool ret;
> + int seq;
> +
> + for (;;) {
> + ret = false;
> + if (!nfs4_valid_open_stateid(state))
> + break;
> + seq = read_seqbegin(&state->seqlock);
> + if (!nfs4_state_match_open_stateid_other(state, dst)) {
> + if (read_seqretry(&state->seqlock, seq))
> + continue;
> + break;
> + }
> + seqid_open = state->open_stateid.seqid;
> + if (read_seqretry(&state->seqlock, seq))
> + continue;
> +
> + dst_seqid = be32_to_cpu(dst->seqid);
> + if ((s32)(dst_seqid - be32_to_cpu(seqid_open)) >= 0)
> + dst->seqid = cpu_to_be32(dst_seqid + 1);
> + else
> + dst->seqid = seqid_open;
> + ret = true;
> + break;
> + }
> +
> + return ret;
> +}
> +
> struct nfs4_closedata {
> struct inode *inode;
> struct nfs4_state *state;
> @@ -3382,7 +3451,7 @@ static void nfs4_close_done(struct rpc_task *task, void *data)
> break;
> case -NFS4ERR_OLD_STATEID:
> /* Did we race with OPEN? */
> - if (nfs4_refresh_open_stateid(&calldata->arg.stateid,
> + if (nfs4_refresh_open_old_stateid(&calldata->arg.stateid,
> state))
> goto out_restart;
> goto out_release;
> @@ -3451,8 +3520,8 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data)
> } else if (is_rdwr)
> calldata->arg.fmode |= FMODE_READ|FMODE_WRITE;
>
> - if (!nfs4_valid_open_stateid(state) ||
> - !nfs4_refresh_open_stateid(&calldata->arg.stateid, state))
> + nfs4_sync_open_stateid(&calldata->arg.stateid, state);
> + if (!nfs4_valid_open_stateid(state))
> call_close = 0;
> spin_unlock(&state->owner->so_lock);
>
> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> index cad4e064b328..e23945174da4 100644
> --- a/fs/nfs/nfs4state.c
> +++ b/fs/nfs/nfs4state.c
> @@ -1015,22 +1015,6 @@ static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
> return ret;
> }
>
> -bool nfs4_refresh_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
> -{
> - bool ret;
> - int seq;
> -
> - do {
> - ret = false;
> - seq = read_seqbegin(&state->seqlock);
> - if (nfs4_state_match_open_stateid_other(state, dst)) {
> - dst->seqid = state->open_stateid.seqid;
> - ret = true;
> - }
> - } while (read_seqretry(&state->seqlock, seq));
> - return ret;
> -}
> -
> bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
> {
> bool ret;
> --
> 2.21.0
>
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> trond.myklebust@xxxxxxxxxxxxxxx
>
>
