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

Frank van der Linden
2019-09-12T17:46:04Z

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