[PATCH v2 04/13] NFSv4.2: query the server for extended attribute support

Frank van der Linden
2020-03-25T23:11:08Z

Query the server for extended attribute support, and record it
as the NFS_CAP_XATTR flag in the server capabilities.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
---
fs/nfs/client.c | 3 +++
fs/nfs/nfs4proc.c | 3 ++-
fs/nfs/nfs4xdr.c | 25 +++++++++++++++++++++++++
include/linux/nfs_fs_sb.h | 1 +
include/linux/nfs_xdr.h | 1 +
5 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index eef39a4ec114..234635ef307e 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -808,6 +808,9 @@ static void nfs_server_set_fsinfo(struct nfs_server *server,
XATTR_SIZE_MAX);
server->lxasize = min_t(unsigned int, raw_max_rpc_payload,
nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
+
+ if (fsinfo->xattr_support)
+ server->caps |= NFS_CAP_XATTR;
#endif
}

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 69b7ab7a5815..11eac1b46749 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -256,6 +256,7 @@ const u32 nfs4_fsinfo_bitmap[3] = { FATTR4_WORD0_MAXFILESIZE
| FATTR4_WORD1_FS_LAYOUT_TYPES,
FATTR4_WORD2_LAYOUT_BLKSIZE
| FATTR4_WORD2_CLONE_BLKSIZE
+ | FATTR4_WORD2_XATTR_SUPPORT
};

const u32 nfs4_fs_locations_bitmap[3] = {
@@ -3737,7 +3738,7 @@ static void nfs4_close_context(struct nfs_open_context *ctx, int is_sync)

#define FATTR4_WORD1_NFS40_MASK (2*FATTR4_WORD1_MOUNTED_ON_FILEID - 1UL)
#define FATTR4_WORD2_NFS41_MASK (2*FATTR4_WORD2_SUPPATTR_EXCLCREAT - 1UL)
-#define FATTR4_WORD2_NFS42_MASK (2*FATTR4_WORD2_MODE_UMASK - 1UL)
+#define FATTR4_WORD2_NFS42_MASK (2*FATTR4_WORD2_XATTR_SUPPORT - 1UL)

static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
{
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 47817ef0aadb..9e1b07640e9a 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4201,6 +4201,26 @@ static int decode_attr_time_modify(struct xdr_stream *xdr, uint32_t *bitmap, str
return status;
}

+static int decode_attr_xattrsupport(struct xdr_stream *xdr, uint32_t *bitmap,
+ uint32_t *res)
+{
+ __be32 *p;
+
+ *res = 0;
+ if (unlikely(bitmap[2] & (FATTR4_WORD2_XATTR_SUPPORT - 1U)))
+ return -EIO;
+ if (likely(bitmap[2] & FATTR4_WORD2_XATTR_SUPPORT)) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ return -EIO;
+ *res = be32_to_cpup(p);
+ bitmap[2] &= ~FATTR4_WORD2_XATTR_SUPPORT;
+ }
+ dprintk("%s: XATTR support=%s\n", __func__,
+ *res == 0 ? "false" : "true");
+ return 0;
+}
+
static int verify_attr_len(struct xdr_stream *xdr, unsigned int savep, uint32_t attrlen)
{
unsigned int attrwords = XDR_QUADLEN(attrlen);
@@ -4855,6 +4875,11 @@ static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
if (status)
goto xdr_error;

+ status = decode_attr_xattrsupport(xdr, bitmap,
+ &fsinfo->xattr_support);
+ if (status)
+ goto xdr_error;
+
status = verify_attr_len(xdr, savep, attrlen);
xdr_error:
dprintk("%s: xdr returned %d!\n", __func__, -status);
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 128e01acb4ca..7eae72a8762e 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -286,5 +286,6 @@ struct nfs_server {
#define NFS_CAP_OFFLOAD_CANCEL (1U << 25)
#define NFS_CAP_LAYOUTERROR (1U << 26)
#define NFS_CAP_COPY_NOTIFY (1U << 27)
+#define NFS_CAP_XATTR (1U << 28)

#endif
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 94c77ed55ce1..6fb1f2b65db3 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -149,6 +149,7 @@ struct nfs_fsinfo {
__u32 layouttype[NFS_MAX_LAYOUT_TYPES]; /* supported pnfs layout driver */
__u32 blksize; /* preferred pnfs io block size */
__u32 clone_blksize; /* granularity of a CLONE operation */
+ __u32 xattr_support; /* User xattrs supported */
};

struct nfs_fsstat {
--
2.17.2