nfsd41: CREATE_EXCLUSIVE4_1
Implement the CREATE_EXCLUSIVE4_1 open mode conforming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26
This mode allows the client to atomically create a file
if it doesn't exist while setting some of its attributes.
It must be implemented if the server supports persistent
reply cache and/or pnfs.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index e206053..b2883e9 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -93,6 +93,21 @@
open->op_truncate = 0;
if (open->op_create) {
+ /* FIXME: check session persistence and pnfs flags.
+ * The nfsv4.1 spec requires the following semantics:
+ *
+ * Persistent | pNFS | Server REQUIRED | Client Allowed
+ * Reply Cache | server | |
+ * -------------+--------+-----------------+--------------------
+ * no | no | EXCLUSIVE4_1 | EXCLUSIVE4_1
+ * | | | (SHOULD)
+ * | | and EXCLUSIVE4 | or EXCLUSIVE4
+ * | | | (SHOULD NOT)
+ * no | yes | EXCLUSIVE4_1 | EXCLUSIVE4_1
+ * yes | no | GUARDED4 | GUARDED4
+ * yes | yes | GUARDED4 | GUARDED4
+ */
+
/*
* Note: create modes (UNCHECKED,GUARDED...) are the same
* in NFSv4 as in v3.
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 533d14f..b820c31 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -260,6 +260,12 @@
NFSD_WRITEABLE_ATTRS_WORD2
};
+static u32 nfsd41_ex_attrmask[] = {
+ NFSD_SUPPATTR_EXCLCREAT_WORD0,
+ NFSD_SUPPATTR_EXCLCREAT_WORD1,
+ NFSD_SUPPATTR_EXCLCREAT_WORD2
+};
+
static __be32
nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, u32 *writable,
struct iattr *iattr, struct nfs4_acl **acl)
@@ -684,6 +690,17 @@
READ_BUF(8);
COPYMEM(open->op_verf.data, 8);
break;
+ case NFS4_CREATE_EXCLUSIVE4_1:
+ if (argp->minorversion < 1)
+ goto xdr_error;
+ READ_BUF(8);
+ COPYMEM(open->op_verf.data, 8);
+ status = nfsd4_decode_fattr(argp, open->op_bmval,
+ nfsd41_ex_attrmask, &open->op_iattr,
+ &open->op_acl);
+ if (status)
+ goto out;
+ break;
default:
goto xdr_error;
}