The ACL value is fetched as a part of inode initialization
from the server and the permission checking function use the
cached value of the ACL

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/9p/Kconfig     |   13 +++++++
 fs/9p/Makefile    |    1 +
 fs/9p/acl.c       |   95 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/9p/acl.h       |   27 +++++++++++++++
 fs/9p/vfs_inode.c |   11 +++++-
 fs/9p/vfs_super.c |    9 ++++-
 fs/9p/xattr.c     |   48 +++++++++++++++-----------
 fs/9p/xattr.h     |    4 ++
 8 files changed, 185 insertions(+), 23 deletions(-)
 create mode 100644 fs/9p/acl.c
 create mode 100644 fs/9p/acl.h

diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig
index 7952337..7e05114 100644
--- a/fs/9p/Kconfig
+++ b/fs/9p/Kconfig
@@ -17,3 +17,16 @@ config 9P_FSCACHE
 	  Choose Y here to enable persistent, read-only local
 	  caching support for 9p clients using FS-Cache
 
+
+config 9P_FS_POSIX_ACL
+	bool "9P POSIX Access Control Lists"
+	depends on 9P_FS
+	select FS_POSIX_ACL
+	help
+	  POSIX Access Control Lists (ACLs) support permissions for users and
+	  groups beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N
diff --git a/fs/9p/Makefile b/fs/9p/Makefile
index 91fba02..f8ba37e 100644
--- a/fs/9p/Makefile
+++ b/fs/9p/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_9P_FS) := 9p.o
 	xattr_user.o
 
 9p-$(CONFIG_9P_FSCACHE) += cache.o
+9p-$(CONFIG_9P_FS_POSIX_ACL) += acl.o
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
new file mode 100644
index 0000000..5de599b
--- /dev/null
+++ b/fs/9p/acl.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright IBM Corporation, 2010
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * ...
[ message continues ]

This patch implement fetching POSIX ACL from the server

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/9p/acl.c   |   63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/9p/xattr.c |    4 +++
 fs/9p/xattr.h |    2 +
 3 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 5de599b..e122e63 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -93,3 +93,66 @@ int v9fs_check_acl(struct inode *inode, int mask)
 	}
 	return -EAGAIN;
 }
+
+static size_t v9fs_xattr_list_acl_access(struct dentry *dentry, char *list,
+					 size_t list_len, const char *name,
+					 size_t name_len, int type)
+{
+	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
+	if (list && size <= list_len)
+		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
+	return size;
+}
+
+static size_t v9fs_xattr_list_acl_default(struct dentry *dentry, char *list,
+					  size_t list_len, const char *name,
+					  size_t name_len, int type)
+{
+	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
+	if (list && size <= list_len)
+		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
+	return size;
+}
+
+static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
+			      void *buffer, size_t size, int type)
+{
+	struct posix_acl *acl;
+	int error;
+
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+
+	acl = v9fs_get_cached_acl(dentry->d_inode, type);
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (acl == NULL)
+		return -ENODATA;
+	error = posix_acl_to_xattr(acl, buffer, size);
+	posix_acl_release(acl);
+
+	return error;
+}
+
+static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
+			      const void *value, size_t size,
+			      int flags, int type)
+{
+	return 0;
+}
+
+const struct xattr_handler v9fs_xattr_acl_access_handler = {
+	.prefix	= POSIX_ACL_XATTR_ACCESS,
+	.flags	= ACL_TYPE_ACCESS,
+	.list	= v9fs_xattr_list_acl_access,
+	.get	= v9fs_xattr_get_acl,
+	.set	= ...
[ message continues ]