Patch "NFSD: Shrink size of struct nfsd4_copy" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSD: Shrink size of struct nfsd4_copy

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-shrink-size-of-struct-nfsd4_copy.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 56fd31a1888c1f590b7445c86e52ed954b3b1e1c
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Wed Jul 27 14:40:22 2022 -0400

    NFSD: Shrink size of struct nfsd4_copy
    
    [ Upstream commit 87689df694916c40e8e6c179ab1c8710f65cb6c6 ]
    
    struct nfsd4_copy is part of struct nfsd4_op, which resides in an
    8-element array.
    
    sizeof(struct nfsd4_op):
    Before: /* size: 1696, cachelines: 27, members: 5 */
    After:  /* size: 672, cachelines: 11, members: 5 */
    
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 80ec51a89d5b5..f0722d4ed0810 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1291,6 +1291,7 @@ void nfs4_put_copy(struct nfsd4_copy *copy)
 {
 	if (!refcount_dec_and_test(&copy->refcount))
 		return;
+	kfree(copy->cp_src);
 	kfree(copy);
 }
 
@@ -1545,7 +1546,7 @@ nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
 	if (status)
 		goto out;
 
-	status = nfsd4_interssc_connect(&copy->cp_src, rqstp, mount);
+	status = nfsd4_interssc_connect(copy->cp_src, rqstp, mount);
 	if (status)
 		goto out;
 
@@ -1753,7 +1754,7 @@ static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
 		dst->nf_src = nfsd_file_get(src->nf_src);
 
 	memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src->cp_stateid));
-	memcpy(&dst->cp_src, &src->cp_src, sizeof(struct nl4_server));
+	memcpy(dst->cp_src, src->cp_src, sizeof(struct nl4_server));
 	memcpy(&dst->stateid, &src->stateid, sizeof(src->stateid));
 	memcpy(&dst->c_fh, &src->c_fh, sizeof(src->c_fh));
 	dst->ss_mnt = src->ss_mnt;
@@ -1847,6 +1848,9 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
 		if (!async_copy)
 			goto out_err;
+		async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL);
+		if (!async_copy->cp_src)
+			goto out_err;
 		if (!nfs4_init_copy_state(nn, copy))
 			goto out_err;
 		refcount_set(&async_copy->refcount, 1);
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 515edc1b662e1..dad744d44b0a2 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1920,6 +1920,9 @@ nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
 
 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
 		return nfserr_bad_xdr;
+	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
+	if (copy->cp_src == NULL)
+		return nfserr_jukebox;
 	copy->cp_intra = false;
 	if (count == 0) { /* intra-server copy */
 		copy->cp_intra = true;
@@ -1927,7 +1930,7 @@ nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
 	}
 
 	/* decode all the supplied server addresses but use only the first */
-	status = nfsd4_decode_nl4_server(argp, &copy->cp_src);
+	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
 	if (status)
 		return status;
 
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 6673c2980c77e..ed90843a55293 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -540,7 +540,7 @@ struct nfsd4_copy {
 	u64			cp_src_pos;
 	u64			cp_dst_pos;
 	u64			cp_count;
-	struct nl4_server	cp_src;
+	struct nl4_server	*cp_src;
 	bool			cp_intra;
 
 	/* both */