On Tue, 2025-03-04 at 12:38 -0800, Dai Ngo wrote:
> RFC8881, section 9.1.2 says:
>
> "In the case of READ, the server may perform the corresponding
> check on the access mode, or it may choose to allow READ for
> OPEN4_SHARE_ACCESS_WRITE, to accommodate clients whose WRITE
> implementation may unavoidably do (e.g., due to buffer cache
> constraints)."
>
> and in section 10.4.1:
> "Similarly, when closing a file opened for OPEN4_SHARE_ACCESS_WRITE/
> OPEN4_SHARE_ACCESS_BOTH and if an OPEN_DELEGATE_WRITE delegation
> is in effect"
>
> This patch offers write delegation for OPEN with OPEN4_SHARE_ACCESS_WRITE
> only. Also deleted no longer use find_rw_file().
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 34 +++++++++++++---------------------
> 1 file changed, 13 insertions(+), 21 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 0f97f2c62b3a..b533225e57cf 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -633,18 +633,6 @@ find_readable_file(struct nfs4_file *f)
> return ret;
> }
>
> -static struct nfsd_file *
> -find_rw_file(struct nfs4_file *f)
> -{
> - struct nfsd_file *ret;
> -
> - spin_lock(&f->fi_lock);
> - ret = nfsd_file_get(f->fi_fds[O_RDWR]);
> - spin_unlock(&f->fi_lock);
> -
> - return ret;
> -}
> -
> struct nfsd_file *
> find_any_file(struct nfs4_file *f)
> {
> @@ -5382,7 +5370,6 @@ static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
> if (dp->dl_stid.sc_status)
> /* CLOSED or REVOKED */
> return 1;
> -
> switch (task->tk_status) {
> case 0:
> return 1;
> @@ -5987,14 +5974,19 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> * "An OPEN_DELEGATE_WRITE delegation allows the client to handle,
> * on its own, all opens."
> *
> - * Furthermore the client can use a write delegation for most READ
> - * operations as well, so we require a O_RDWR file here.
> + * Furthermore, section 9.1.2 says:
> + *
> + * "In the case of READ, the server may perform the corresponding
> + * check on the access mode, or it may choose to allow READ for
> + * OPEN4_SHARE_ACCESS_WRITE, to accommodate clients whose WRITE
> + * implementation may unavoidably do (e.g., due to buffer cache
> + * constraints)."
> *
> - * Offer a write delegation in the case of a BOTH open, and ensure
> - * we get the O_RDWR descriptor.
> + * We choose to offer a write delegation for OPEN with the
> + * OPEN4_SHARE_ACCESS_WRITE access mode to accommodate such clients.
> */
> - if ((open->op_share_access & NFS4_SHARE_ACCESS_BOTH) == NFS4_SHARE_ACCESS_BOTH) {
> - nf = find_rw_file(fp);
> + if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
> + nf = find_writeable_file(fp);
> dl_type = deleg_ts ? OPEN_DELEGATE_WRITE_ATTRS_DELEG : OPEN_DELEGATE_WRITE;
> }
>
> @@ -6116,7 +6108,7 @@ static bool
> nfs4_delegation_stat(struct nfs4_delegation *dp, struct svc_fh *currentfh,
> struct kstat *stat)
> {
> - struct nfsd_file *nf = find_rw_file(dp->dl_stid.sc_file);
> + struct nfsd_file *nf = find_writeable_file(dp->dl_stid.sc_file);
> struct path path;
> int rc;
>
> @@ -7063,7 +7055,7 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
> return_revoked = true;
> if (typemask & SC_TYPE_DELEG)
> /* Always allow REVOKED for DELEG so we can
> - * retturn the appropriate error.
> + * return the appropriate error.
> */
> statusmask |= SC_STATUS_REVOKED;
>
This patch also looks good.
The only other issue I have with this is the patch ordering. If a
bisect lands between these two patches then delegations won't work
quite right. Is there a reason to order the patches this way?
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
