[PATCH v4 02/11] NFSD: Track transport in DRC entries

[Chuck Lever <cel@kernel.org>]

A cached reply carries no record of the transport its request arrived
on. Transport-aware eviction needs that association.

Record the xprt id in each entry. It fits the padding after the flag
bytes, so struct nfsd_cacherep stays at 128 bytes. No behavior change.

Assisted-by: LLM
Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/cache.h    | 1 +
 fs/nfsd/nfscache.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h
index 3bc4856e34b8..90ecc270640c 100644
--- a/fs/nfsd/cache.h
+++ b/fs/nfsd/cache.h
@@ -37,6 +37,7 @@ struct nfsd_cacherep {
 	unsigned char		c_state,	/* unused, inprog, done */
 				c_type,		/* status, buffer */
 				c_secure : 1;	/* req came from port < 1024 */
+	u32			c_xprt;		/* svc_xprt that carried req */
 	unsigned long		c_timestamp;
 	union {
 		struct kvec	u_vec;
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 80364b91331a..b25b4f9e92f7 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -109,6 +109,7 @@ nfsd_cacherep_alloc(struct svc_rqst *rqstp, __wsum csum,
 		rp->c_key.k_vers = rqstp->rq_vers;
 		rp->c_key.k_len = rqstp->rq_arg.len;
 		rp->c_key.k_csum = csum;
+		rp->c_xprt = rqstp->rq_xprt->xpt_id;
 	}
 	return rp;
 }

-- 
2.55.0