NFS: Request fh_expire_type attribute in "server caps" operation
The fh_expire_type file attribute is a filesystem wide attribute that
consists of flags that indicate what characteristics file handles
on this FSID have.
Our client doesn't support volatile file handles. It should find
out early (say, at mount time) whether the server is going to play
shenanighans with file handles during a migration.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index a6fb55d..3e0fe9f 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2676,6 +2676,7 @@
encode_sequence(xdr, &args->seq_args, &hdr);
encode_putfh(xdr, args->fhandle, &hdr);
encode_getattr_one(xdr, FATTR4_WORD0_SUPPORTED_ATTRS|
+ FATTR4_WORD0_FH_EXPIRE_TYPE|
FATTR4_WORD0_LINK_SUPPORT|
FATTR4_WORD0_SYMLINK_SUPPORT|
FATTR4_WORD0_ACLSUPPORT, &hdr);
@@ -3223,6 +3224,28 @@
return -EIO;
}
+static int decode_attr_fh_expire_type(struct xdr_stream *xdr,
+ uint32_t *bitmap, uint32_t *type)
+{
+ __be32 *p;
+
+ *type = 0;
+ if (unlikely(bitmap[0] & (FATTR4_WORD0_FH_EXPIRE_TYPE - 1U)))
+ return -EIO;
+ if (likely(bitmap[0] & FATTR4_WORD0_FH_EXPIRE_TYPE)) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ *type = be32_to_cpup(p);
+ bitmap[0] &= ~FATTR4_WORD0_FH_EXPIRE_TYPE;
+ }
+ dprintk("%s: expire type=0x%x\n", __func__, *type);
+ return 0;
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+}
+
static int decode_attr_change(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *change)
{
__be32 *p;
@@ -4271,6 +4294,9 @@
goto xdr_error;
if ((status = decode_attr_supported(xdr, bitmap, res->attr_bitmask)) != 0)
goto xdr_error;
+ if ((status = decode_attr_fh_expire_type(xdr, bitmap,
+ &res->fh_expire_type)) != 0)
+ goto xdr_error;
if ((status = decode_attr_link_support(xdr, bitmap, &res->has_links)) != 0)
goto xdr_error;
if ((status = decode_attr_symlink_support(xdr, bitmap, &res->has_symlinks)) != 0)