[RFC PATCH 06/35] NFSv4.2: define and set initial limits for extended attributes

[Frank van der Linden <fllinden@amazon.com>]

Set limits for extended attributes (attribute value size and listxattr
buffer size), based on the fs-independent limits (XATTR_*_MAX).

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
---
 fs/nfs/client.c           | 17 +++++++++++++++--
 include/linux/nfs_fs_sb.h |  5 +++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 30838304a0bf..4a988787049c 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -50,6 +50,7 @@
 #include "nfs.h"
 #include "netns.h"
 #include "sysfs.h"
+#include "nfs42.h"
 
 #define NFSDBG_FACILITY		NFSDBG_CLIENT
 
@@ -733,7 +734,7 @@ static int nfs_init_server(struct nfs_server *server,
 static void nfs_server_set_fsinfo(struct nfs_server *server,
 				  struct nfs_fsinfo *fsinfo)
 {
-	unsigned long max_rpc_payload;
+	unsigned long max_rpc_payload, raw_max_rpc_payload;
 
 	/* Work out a lot of parameters */
 	if (server->rsize == 0)
@@ -746,7 +747,9 @@ static void nfs_server_set_fsinfo(struct nfs_server *server,
 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
 
-	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
+	raw_max_rpc_payload = rpc_max_payload(server->client);
+	max_rpc_payload = nfs_block_size(raw_max_rpc_payload, NULL);
+
 	if (server->rsize > max_rpc_payload)
 		server->rsize = max_rpc_payload;
 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
@@ -779,6 +782,16 @@ static void nfs_server_set_fsinfo(struct nfs_server *server,
 	server->clone_blksize = fsinfo->clone_blksize;
 	/* We're airborne Set socket buffersize */
 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
+
+#ifdef CONFIG_NFS_V4_XATTR
+	/*
+	 * Defaults until limited by the session parameters.
+	 */
+	server->gxasize = min_t(unsigned, raw_max_rpc_payload, XATTR_SIZE_MAX);
+	server->sxasize = min_t(unsigned, raw_max_rpc_payload, XATTR_SIZE_MAX);
+	server->lxasize = min_t(unsigned, raw_max_rpc_payload,
+				nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
+#endif
 }
 
 /*
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 290d1c521226..db190a139d26 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -160,6 +160,11 @@ struct nfs_server {
 	unsigned int		dtsize;		/* readdir size */
 	unsigned short		port;		/* "port=" setting */
 	unsigned int		bsize;		/* server block size */
+#ifdef CONFIG_NFS_V4_XATTR
+	unsigned int		gxasize;	/* getxattr size */
+	unsigned int		sxasize;	/* setxattr size */
+	unsigned int		lxasize;	/* listxattr size */
+#endif
 	unsigned int		acregmin;	/* attr cache timeouts */
 	unsigned int		acregmax;
 	unsigned int		acdirmin;
-- 
2.17.2