On Thu, Apr 28, 2022 at 12:06:30AM -0700, Dai Ngo wrote:
> This patch allows expired client with open state to be in COURTESY
> state. Share/access conflict with COURTESY client is resolved by
> setting COURTESY client to EXPIRABLE state, schedule laundromat
> to run and returning nfserr_jukebox to the request client.
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 104 insertions(+), 8 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index b84ba19c856b..d2cb820de0ab 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -694,6 +694,57 @@ static unsigned int file_hashval(struct svc_fh *fh)
>
> static struct hlist_head file_hashtbl[FILE_HASH_SIZE];
>
> +/*
> + * Check if courtesy clients have conflicting access and resolve it if possible
> + *
> + * access: is op_share_access if share_access is true.
> + * Check if access mode, op_share_access, would conflict with
> + * the current deny mode of the file 'fp'.
> + * access: is op_share_deny if share_access is false.
> + * Check if the deny mode, op_share_deny, would conflict with
> + * current access of the file 'fp'.
> + * stp: skip checking this entry.
> + * new_stp: normal open, not open upgrade.
> + *
> + * Function returns:
> + * false - access/deny mode conflict with normal client.
> + * true - no conflict or conflict with courtesy client(s) is resolved.
> + */
> +static bool
> +nfs4_resolve_deny_conflicts_locked(struct nfs4_file *fp, bool new_stp,
> + struct nfs4_ol_stateid *stp, u32 access, bool share_access)
> +{
> + struct nfs4_ol_stateid *st;
> + bool conflict = true;
> + unsigned char bmap;
> + struct nfsd_net *nn;
> + struct nfs4_client *clp;
> +
> + lockdep_assert_held(&fp->fi_lock);
> + list_for_each_entry(st, &fp->fi_stateids, st_perfile) {
> + /* ignore lock stateid */
> + if (st->st_openstp)
> + continue;
> + if (st == stp && new_stp)
> + continue;
> + /* check file access against deny mode or vice versa */
> + bmap = share_access ? st->st_deny_bmap : st->st_access_bmap;
> + if (!(access & bmap_to_share_mode(bmap)))
> + continue;
> + clp = st->st_stid.sc_client;
> + if (try_to_expire_client(clp))
> + continue;
> + conflict = false;
> + break;
> + }
> + if (conflict) {
> + clp = stp->st_stid.sc_client;
> + nn = net_generic(clp->net, nfsd_net_id);
> + mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
> + }
> + return conflict;
"conflict" is a confusing name for that variable. Maybe "resolvable"?
--b.
> +}
> +
> static void
> __nfs4_file_get_access(struct nfs4_file *fp, u32 access)
> {
> @@ -4959,7 +5010,7 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
>
> static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
> struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,
> - struct nfsd4_open *open)
> + struct nfsd4_open *open, bool new_stp)
> {
> struct nfsd_file *nf = NULL;
> __be32 status;
> @@ -4975,6 +5026,13 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
> */
> status = nfs4_file_check_deny(fp, open->op_share_deny);
> if (status != nfs_ok) {
> + if (status != nfserr_share_denied) {
> + spin_unlock(&fp->fi_lock);
> + goto out;
> + }
> + if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,
> + stp, open->op_share_deny, false))
> + status = nfserr_jukebox;
> spin_unlock(&fp->fi_lock);
> goto out;
> }
> @@ -4982,6 +5040,13 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
> /* set access to the file */
> status = nfs4_file_get_access(fp, open->op_share_access);
> if (status != nfs_ok) {
> + if (status != nfserr_share_denied) {
> + spin_unlock(&fp->fi_lock);
> + goto out;
> + }
> + if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,
> + stp, open->op_share_access, true))
> + status = nfserr_jukebox;
> spin_unlock(&fp->fi_lock);
> goto out;
> }
> @@ -5028,21 +5093,29 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
> }
>
> static __be32
> -nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open)
> +nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp,
> + struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,
> + struct nfsd4_open *open)
> {
> __be32 status;
> unsigned char old_deny_bmap = stp->st_deny_bmap;
>
> if (!test_access(open->op_share_access, stp))
> - return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open);
> + return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open, false);
>
> /* test and set deny mode */
> spin_lock(&fp->fi_lock);
> status = nfs4_file_check_deny(fp, open->op_share_deny);
> if (status == nfs_ok) {
> - set_deny(open->op_share_deny, stp);
> - fp->fi_share_deny |=
> + if (status != nfserr_share_denied) {
> + set_deny(open->op_share_deny, stp);
> + fp->fi_share_deny |=
> (open->op_share_deny & NFS4_SHARE_DENY_BOTH);
> + } else {
> + if (nfs4_resolve_deny_conflicts_locked(fp, false,
> + stp, open->op_share_deny, false))
> + status = nfserr_jukebox;
> + }
> }
> spin_unlock(&fp->fi_lock);
>
> @@ -5383,7 +5456,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
> goto out;
> }
> } else {
> - status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open);
> + status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open, true);
> if (status) {
> stp->st_stid.sc_type = NFS4_CLOSED_STID;
> release_open_stateid(stp);
> @@ -5617,12 +5690,35 @@ static void nfsd4_ssc_expire_umount(struct nfsd_net *nn)
> }
> #endif
>
> +static bool
> +nfs4_has_any_locks(struct nfs4_client *clp)
> +{
> + int i;
> + struct nfs4_stateowner *so;
> +
> + spin_lock(&clp->cl_lock);
> + for (i = 0; i < OWNER_HASH_SIZE; i++) {
> + list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[i],
> + so_strhash) {
> + if (so->so_is_open_owner)
> + continue;
> + spin_unlock(&clp->cl_lock);
> + return true;
> + }
> + }
> + spin_unlock(&clp->cl_lock);
> + return false;
> +}
> +
> /*
> * place holder for now, no check for lock blockers yet
> */
> static bool
> nfs4_anylock_blockers(struct nfs4_client *clp)
> {
> + /* not allow locks yet */
> + if (nfs4_has_any_locks(clp))
> + return true;
> /*
> * don't want to check for delegation conflict here since
> * we need the state_lock for it. The laundromat willexpire
> @@ -5633,8 +5729,8 @@ nfs4_anylock_blockers(struct nfs4_client *clp)
>
> static bool client_has_state_tmp(struct nfs4_client *clp)
> {
> - if (!list_empty(&clp->cl_delegations) &&
> - !client_has_openowners(clp) &&
> + if (((!list_empty(&clp->cl_delegations)) ||
> + client_has_openowners(clp)) &&
> list_empty(&clp->async_copies))
> return true;
> return false;
> --
> 2.9.5
