[PATCH v1 03/17] nfs_common: Export posix_acl_from_nfsacl for server ACL codecs

[Chuck Lever <cel@kernel.org>]

The NFS_ACLv2 secattr decode is moving off the hand-rolled
nfs_stream_decode_acl onto generated code driven by application hooks in
nfsd.  Those hooks finalize a decoded ACL with the same
Solaris-to-POSIX normalization nfs_stream_decode_acl performs
internally: the entry sort and the removal of the bogus ACL_MASK
entry Solaris adds to a minimal ACL.

Export that normalization and describe its contract so the hook
layer shares one implementation instead of duplicating it.  The
still-hand-rolled callers keep using it internally, unchanged.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfs_common/nfsacl.c | 13 ++++++++++---
 include/linux/nfsacl.h |  2 ++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c
index 24ee7f622b18..09d941303d16 100644
--- a/fs/nfs_common/nfsacl.c
+++ b/fs/nfs_common/nfsacl.c
@@ -288,10 +288,16 @@ cmp_acl_entry(const void *x, const void *y)
 		return 0;
 }
 
-/*
- * Convert from a Solaris ACL to a POSIX 1003.1e draft 17 ACL.
+/**
+ * posix_acl_from_nfsacl - Normalize a decoded Solaris ACL in place
+ * @acl: a posix_acl decoded from the NFSACL wire form, or NULL
+ *
+ * Sorts the entries into POSIX 1003.1e draft 17 order and removes the
+ * bogus ACL_MASK entry Solaris adds to a minimal ACL.
+ *
+ * Return: 0.  Always succeeds; a NULL @acl is a no-op.
  */
-static int
+int
 posix_acl_from_nfsacl(struct posix_acl *acl)
 {
 	struct posix_acl_entry *pa, *pe,
@@ -327,6 +333,7 @@ posix_acl_from_nfsacl(struct posix_acl *acl)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(posix_acl_from_nfsacl);
 
 /**
  * nfsacl_decode - Decode an NFSv3 ACL
diff --git a/include/linux/nfsacl.h b/include/linux/nfsacl.h
index e4155e69c8dd..7d7709a0a56e 100644
--- a/include/linux/nfsacl.h
+++ b/include/linux/nfsacl.h
@@ -45,5 +45,7 @@ nfs_stream_decode_acl(struct xdr_stream *xdr, unsigned int *aclcnt,
 extern bool
 nfs_stream_encode_acl(struct xdr_stream *xdr, struct inode *inode,
 		      struct posix_acl *acl, int encode_entries, int typeflag);
+extern int
+posix_acl_from_nfsacl(struct posix_acl *acl);
 
 #endif  /* __LINUX_NFSACL_H */
-- 
2.56.0