[RFC PATCH v2 03/11] NFS/NFSD: data structure enablement for nfs4_acl passthru support

Mike Snitzer
2026-02-24T19:24:43Z

Add setacl and getacl to export_operations structure. Both of these
methods allow NFSD to pass an nfs4_acl structure to exported
filesystem.

Update the nfs4_acl structure to allow for dual use of the new
nfs4_acl passthru support in addition to its existing usage. This
duality is reflected through use of a union, but the xdr_buf payload
is used to initialize all members in the union needed for passthru (in
a later NFSD commit).

Move nfs4_acl_type structure to include/linux/nfsacl.h so that it can
be used by NFS and NFSD.

Signed-off-by: Mike Snitzer <snitzer@hammerspace.com>
---
include/linux/exportfs.h | 9 +++++++++
include/linux/nfs4.h | 23 +++++++++++++++++++++--
include/linux/nfs_xdr.h | 7 -------
include/linux/nfsacl.h | 7 +++++++
4 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index 7823c9693346..9e3a818019f8 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -11,6 +11,7 @@ struct inode;
struct iomap;
struct super_block;
struct vfsmount;
+struct nfs4_acl;

/* limit the handle size to NFSv4 handle size now */
#define MAX_HANDLE_SZ 128
@@ -269,6 +270,12 @@ struct handle_to_path_ctx {
* @commit_blocks:
* Commit blocks in a layout once the client is done with them.
*
+ * @setacl:
+ * @setacl will use the nfs4_acl @acl to establish the acl using SETATTR.
+ *
+ * @getacl:
+ * @getacl will use the nfs4_acl @acl to retrieve the acl using GETATTR.
+ *
* @flags:
* Allows the filesystem to communicate to nfsd that it may want to do things
* differently when dealing with it.
@@ -298,6 +305,8 @@ struct export_operations {
int nr_iomaps, struct iattr *iattr);
int (*permission)(struct handle_to_path_ctx *ctx, unsigned int oflags);
struct file * (*open)(const struct path *path, unsigned int oflags);
+ int (*setacl)(struct inode *inode, struct nfs4_acl *acl);
+ int (*getacl)(struct inode *inode, struct nfs4_acl *acl);
#define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */
#define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */
#define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index d87be1f25273..8cfa748c7efa 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -16,6 +16,7 @@
#include <linux/list.h>
#include <linux/uidgid.h>
#include <uapi/linux/nfs4.h>
+#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/xdrgen/nfs4_1.h>

@@ -38,8 +39,26 @@ struct nfs4_ace {
};

struct nfs4_acl {
- uint32_t naces;
- struct nfs4_ace aces[];
+ union {
+ struct {
+ /*
+ * Payload to use for deferred decode into
+ * pages once ACL passthru is required
+ * (which uses abnormal members below).
+ */
+ struct xdr_buf payload;
+ /* Normal counted list of ACEs */
+ uint32_t naces;
+ struct nfs4_ace aces[];
+ } __attribute__ ((packed));
+ struct {
+ /* Abnormal counted list of pages */
+ uint32_t type;
+ uint32_t len;
+ uint32_t pgbase;
+ struct page *pages[];
+ } __attribute__ ((packed));
+ };
};

#define NFS4_MAXLABELLEN 2048
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index ff1f12aa73d2..3260d3116127 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -828,13 +828,6 @@ struct nfs_setattrargs {
const struct nfs4_label *label;
};

-enum nfs4_acl_type {
- NFS4ACL_NONE = 0,
- NFS4ACL_ACL,
- NFS4ACL_DACL,
- NFS4ACL_SACL,
-};
-
struct nfs_setaclargs {
struct nfs4_sequence_args seq_args;
struct nfs_fh * fh;
diff --git a/include/linux/nfsacl.h b/include/linux/nfsacl.h
index 8e76a79cdc6a..a1941dc56db0 100644
--- a/include/linux/nfsacl.h
+++ b/include/linux/nfsacl.h
@@ -22,6 +22,13 @@
#define NFS_ACL_MAX_ENTRIES_INLINE (5)
#define NFS_ACL_INLINE_BUFSIZE ((2*(2+3*NFS_ACL_MAX_ENTRIES_INLINE)) << 2)

+enum nfs4_acl_type {
+ NFS4ACL_NONE = 0,
+ NFS4ACL_ACL,
+ NFS4ACL_DACL,
+ NFS4ACL_SACL,
+};
+
static inline unsigned int
nfsacl_size(struct posix_acl *acl_access, struct posix_acl *acl_default)
{
--
2.44.0