From: "Aneesh Kumar K.V" <aneesh.ku...@linux.vnet.ibm.com>

Support the richacl permission model in ext4.  The richacls are stored
in "system.richacl" xattrs.  Richacls need to be enabled by tune2fs or
at file system create time.

Signed-off-by: Andreas Gruenbacher <agrue...@redhat.com>
---
 fs/ext4/Kconfig   |  15 ++++
 fs/ext4/Makefile  |   1 +
 fs/ext4/acl.c     |   6 +-
 fs/ext4/acl.h     |  12 +--
 fs/ext4/file.c    |   6 +-
 fs/ext4/ialloc.c  |   7 +-
 fs/ext4/inode.c   |  10 ++-
 fs/ext4/namei.c   |  11 ++-
 fs/ext4/richacl.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ext4/richacl.h |  47 ++++++++++++
 fs/ext4/xattr.c   |   6 ++
 fs/ext4/xattr.h   |   1 +
 12 files changed, 316 insertions(+), 19 deletions(-)
 create mode 100644 fs/ext4/richacl.c
 create mode 100644 fs/ext4/richacl.h

diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index bf8bc8a..77a386d 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -96,3 +96,18 @@ config EXT4_DEBUG
          If you select Y here, then you will be able to turn on debugging
          with a command such as:
                echo 1 > /sys/module/ext4/parameters/mballoc_debug
+
+config EXT4_FS_RICHACL
+       bool "Ext4 Rich Access Control Lists (EXPERIMENTAL)"
+       depends on EXT4_FS
+       select FS_RICHACL
+       help
+         Rich ACLs are an implementation of NFSv4 ACLs, extended by file masks
+         to fit into the standard POSIX file permission model.  They are
+         designed to work seamlessly locally as well as across the NFSv4 and
+         CIFS/SMB2 network file system protocols.
+
+         To learn more about Rich ACL, visit
+         http://acl.bestbits.at/richacl/
+
+         If you don't know what Rich ACLs are, say N
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 75285ea..ea0d539 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -14,3 +14,4 @@ ext4-$(CONFIG_EXT4_FS_POSIX_ACL)      += acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)                += xattr_security.o
 ext4-$(CONFIG_EXT4_FS_ENCRYPTION)      += crypto_policy.o crypto.o \
                crypto_key.o crypto_fname.o
+ext4-$(CONFIG_EXT4_FS_RICHACL)                 += richacl.o
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 69b1e73..d965fa6 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -140,7 +140,7 @@ fail:
  * inode->i_mutex: don't care
  */
 struct posix_acl *
-ext4_get_acl(struct inode *inode, int type)
+ext4_get_posix_acl(struct inode *inode, int type)
 {
        int name_index;
        char *value = NULL;
@@ -234,7 +234,7 @@ __ext4_set_acl(handle_t *handle, struct inode *inode, int 
type,
 }
 
 int
-ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+ext4_set_posix_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
        handle_t *handle;
        int error, retries = 0;
@@ -259,7 +259,7 @@ retry:
  * inode->i_mutex: up (access to inode is still exclusive)
  */
 int
-ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+ext4_init_posix_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 {
        struct posix_acl *default_acl, *acl;
        int error;
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index da2c795..450b4d1 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -54,17 +54,17 @@ static inline int ext4_acl_count(size_t size)
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 
 /* acl.c */
-struct posix_acl *ext4_get_acl(struct inode *inode, int type);
-int ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type);
-extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
+struct posix_acl *ext4_get_posix_acl(struct inode *inode, int type);
+int ext4_set_posix_acl(struct inode *inode, struct posix_acl *acl, int type);
+extern int ext4_init_posix_acl(handle_t *, struct inode *, struct inode *);
 
 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
 #include <linux/sched.h>
-#define ext4_get_acl NULL
-#define ext4_set_acl NULL
+#define ext4_get_posix_acl NULL
+#define ext4_set_posix_acl NULL
 
 static inline int
-ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+ext4_init_posix_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 {
        return 0;
 }
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index bc313ac..3d3fcc8 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -29,6 +29,7 @@
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "richacl.h"
 
 /*
  * Called when an inode is released. Note that this is different
@@ -659,8 +660,9 @@ const struct inode_operations ext4_file_inode_operations = {
        .getxattr       = generic_getxattr,
        .listxattr      = ext4_listxattr,
        .removexattr    = generic_removexattr,
-       .get_acl        = ext4_get_acl,
-       .set_acl        = ext4_set_acl,
+       .get_acl        = ext4_get_posix_acl,
+       .set_acl        = ext4_set_posix_acl,
+       .get_richacl    = ext4_get_richacl,
        .fiemap         = ext4_fiemap,
 };
 
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 173c1ae..aa5d1e1 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -27,6 +27,7 @@
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "richacl.h"
 
 #include <trace/events/ext4.h>
 
@@ -1050,7 +1051,11 @@ got:
        if (err)
                goto fail_drop;
 
-       err = ext4_init_acl(handle, inode, dir);
+       if (EXT4_IS_RICHACL(dir))
+               err = ext4_init_richacl(handle, inode, dir);
+       else
+               err = ext4_init_posix_acl(handle, inode, dir);
+
        if (err)
                goto fail_free_drop;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index cecf9aa..7f6bbe8 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -41,6 +41,7 @@
 #include "xattr.h"
 #include "acl.h"
 #include "truncate.h"
+#include "richacl.h"
 
 #include <trace/events/ext4.h>
 
@@ -4782,9 +4783,12 @@ int ext4_setattr(struct dentry *dentry, struct iattr 
*attr)
        if (orphan && inode->i_nlink)
                ext4_orphan_del(NULL, inode);
 
-       if (!rc && (ia_valid & ATTR_MODE))
-               rc = posix_acl_chmod(inode, inode->i_mode);
-
+       if (!rc && (ia_valid & ATTR_MODE)) {
+               if (EXT4_IS_RICHACL(inode))
+                       rc = ext4_richacl_chmod(inode);
+               else
+                       rc = posix_acl_chmod(inode, inode->i_mode);
+       }
 err_out:
        ext4_std_error(inode->i_sb, error);
        if (!error)
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 011dcfb..9be6a8a 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -38,6 +38,7 @@
 
 #include "xattr.h"
 #include "acl.h"
+#include "richacl.h"
 
 #include <trace/events/ext4.h>
 /*
@@ -3821,8 +3822,9 @@ const struct inode_operations ext4_dir_inode_operations = 
{
        .getxattr       = generic_getxattr,
        .listxattr      = ext4_listxattr,
        .removexattr    = generic_removexattr,
-       .get_acl        = ext4_get_acl,
-       .set_acl        = ext4_set_acl,
+       .get_acl        = ext4_get_posix_acl,
+       .set_acl        = ext4_set_posix_acl,
+       .get_richacl    = ext4_get_richacl,
        .fiemap         = ext4_fiemap,
 };
 
@@ -3832,6 +3834,7 @@ const struct inode_operations 
ext4_special_inode_operations = {
        .getxattr       = generic_getxattr,
        .listxattr      = ext4_listxattr,
        .removexattr    = generic_removexattr,
-       .get_acl        = ext4_get_acl,
-       .set_acl        = ext4_set_acl,
+       .get_acl        = ext4_get_posix_acl,
+       .set_acl        = ext4_set_posix_acl,
+       .get_richacl    = ext4_get_richacl,
 };
diff --git a/fs/ext4/richacl.c b/fs/ext4/richacl.c
new file mode 100644
index 0000000..6758def
--- /dev/null
+++ b/fs/ext4/richacl.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright IBM Corporation, 2010
+ * Copyright (C) 2015  Red Hat, Inc.
+ * Author Aneesh Kumar K.V <aneesh.ku...@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
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/richacl_xattr.h>
+
+#include "ext4.h"
+#include "ext4_jbd2.h"
+#include "xattr.h"
+#include "acl.h"
+#include "richacl.h"
+
+struct richacl *
+ext4_get_richacl(struct inode *inode)
+{
+       const int name_index = EXT4_XATTR_INDEX_RICHACL;
+       void *value = NULL;
+       struct richacl *acl;
+       int retval;
+
+       if (!IS_RICHACL(inode))
+               return ERR_PTR(-EOPNOTSUPP);
+       acl = get_cached_richacl(inode);
+       if (acl != ACL_NOT_CACHED)
+               return acl;
+       retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
+       if (retval > 0) {
+               value = kmalloc(retval, GFP_NOFS);
+               if (!value)
+                       return ERR_PTR(-ENOMEM);
+               retval = ext4_xattr_get(inode, name_index, "", value, retval);
+       }
+       if (retval > 0) {
+               acl = richacl_from_xattr(&init_user_ns, value, retval);
+               if (acl == ERR_PTR(-EINVAL))
+                       acl = ERR_PTR(-EIO);
+       } else if (retval == -ENODATA || retval == -ENOSYS)
+               acl = NULL;
+       else
+               acl = ERR_PTR(retval);
+       kfree(value);
+
+       if (!IS_ERR(acl))
+               set_cached_richacl(inode, acl);
+
+       return acl;
+}
+
+static int
+ext4_set_richacl(handle_t *handle, struct inode *inode, struct richacl *acl)
+{
+       const int name_index = EXT4_XATTR_INDEX_RICHACL;
+       size_t size = 0;
+       void *value = NULL;
+       int retval;
+
+       if (acl) {
+               mode_t mode = inode->i_mode;
+
+               if (richacl_equiv_mode(acl, &mode) == 0) {
+                       inode->i_mode = mode;
+                       ext4_mark_inode_dirty(handle, inode);
+                       acl = NULL;
+               }
+       }
+       if (acl) {
+               size = richacl_xattr_size(acl);
+               value = kmalloc(size, GFP_NOFS);
+               if (!value)
+                       return -ENOMEM;
+               richacl_to_xattr(&init_user_ns, acl, value, size);
+       }
+       if (handle)
+               retval = ext4_xattr_set_handle(handle, inode, name_index, "",
+                                              value, size, 0);
+       else
+               retval = ext4_xattr_set(inode, name_index, "", value, size, 0);
+       kfree(value);
+       if (!retval)
+               set_cached_richacl(inode, acl);
+
+       return retval;
+}
+
+int
+ext4_init_richacl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+       struct richacl *acl = richacl_create(inode, dir);
+       int error;
+
+       error = PTR_ERR(acl);
+       if (IS_ERR(acl))
+               return error;
+       if (acl) {
+               error = ext4_set_richacl(handle, inode, acl);
+               richacl_put(acl);
+       }
+       return error;
+}
+
+int
+ext4_richacl_chmod(struct inode *inode)
+{
+       struct richacl *acl;
+       int retval;
+
+       if (S_ISLNK(inode->i_mode))
+               return -EOPNOTSUPP;
+       acl = ext4_get_richacl(inode);
+       if (IS_ERR_OR_NULL(acl))
+               return PTR_ERR(acl);
+       acl = richacl_chmod(acl, inode->i_mode);
+       if (IS_ERR(acl))
+               return PTR_ERR(acl);
+       retval = ext4_set_richacl(NULL, inode, acl);
+       richacl_put(acl);
+
+       return retval;
+}
+
+static size_t
+ext4_xattr_list_richacl(struct dentry *dentry, char *list, size_t list_len,
+                       const char *name, size_t name_len, int type)
+{
+       const size_t size = sizeof(XATTR_NAME_RICHACL);
+
+       if (!IS_RICHACL(d_inode(dentry)))
+               return 0;
+       if (list && size <= list_len)
+               memcpy(list, XATTR_NAME_RICHACL, size);
+       return size;
+}
+
+static int
+ext4_xattr_get_richacl(struct dentry *dentry, const char *name, void *buffer,
+               size_t buffer_size, int type)
+{
+       struct richacl *acl;
+       int error;
+
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+       acl = ext4_get_richacl(d_inode(dentry));
+       if (IS_ERR(acl))
+               return PTR_ERR(acl);
+       if (acl == NULL)
+               return -ENODATA;
+
+       error = richacl_to_xattr(&init_user_ns, acl, buffer, buffer_size);
+       richacl_put(acl);
+       return error;
+}
+
+static int
+ext4_xattr_set_richacl(struct dentry *dentry, const char *name,
+               const void *value, size_t size, int flags, int type)
+{
+       handle_t *handle;
+       struct richacl *acl = NULL;
+       int retval, retries = 0;
+       struct inode *inode = d_inode(dentry);
+
+       if (!IS_RICHACL(d_inode(dentry)))
+               return -EOPNOTSUPP;
+       if (S_ISLNK(inode->i_mode))
+               return -EOPNOTSUPP;
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+       if (!uid_eq(current_fsuid(), inode->i_uid) &&
+           inode_permission(inode, MAY_CHMOD) &&
+           !capable(CAP_FOWNER))
+               return -EPERM;
+       if (value) {
+               acl = richacl_from_xattr(&init_user_ns, value, size);
+               if (IS_ERR(acl))
+                       return PTR_ERR(acl);
+
+               inode->i_mode &= ~S_IRWXUGO;
+               inode->i_mode |= richacl_masks_to_mode(acl);
+       }
+
+retry:
+       handle = ext4_journal_start(inode, EXT4_HT_XATTR,
+                                   EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
+       if (IS_ERR(handle))
+               return PTR_ERR(handle);
+       retval = ext4_set_richacl(handle, inode, acl);
+       ext4_journal_stop(handle);
+       if (retval == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+               goto retry;
+       richacl_put(acl);
+       return retval;
+}
+
+const struct xattr_handler ext4_richacl_xattr_handler = {
+       .prefix = XATTR_NAME_RICHACL,
+       .list   = ext4_xattr_list_richacl,
+       .get    = ext4_xattr_get_richacl,
+       .set    = ext4_xattr_set_richacl,
+};
diff --git a/fs/ext4/richacl.h b/fs/ext4/richacl.h
new file mode 100644
index 0000000..09a5cad
--- /dev/null
+++ b/fs/ext4/richacl.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright IBM Corporation, 2010
+ * Copyright (C)  2015 Red Hat, Inc.
+ * Author Aneesh Kumar K.V <aneesh.ku...@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
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#ifndef __FS_EXT4_RICHACL_H
+#define __FS_EXT4_RICHACL_H
+
+#include <linux/richacl.h>
+
+#ifdef CONFIG_EXT4_FS_RICHACL
+
+#define EXT4_IS_RICHACL(inode) IS_RICHACL(inode)
+
+extern struct richacl *ext4_get_richacl(struct inode *);
+extern int ext4_init_richacl(handle_t *, struct inode *, struct inode *);
+extern int ext4_richacl_chmod(struct inode *);
+
+#else  /* CONFIG_FS_EXT4_RICHACL */
+
+#define EXT4_IS_RICHACL(inode) (0)
+#define ext4_get_richacl   NULL
+
+static inline int
+ext4_init_richacl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+       return 0;
+}
+
+static inline int
+ext4_richacl_chmod(struct inode *inode)
+{
+       return 0;
+}
+
+#endif  /* CONFIG_FS_EXT4_RICHACL */
+#endif  /* __FS_EXT4_RICHACL_H */
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 16e28c0..c1dee9b 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -99,6 +99,9 @@ static const struct xattr_handler *ext4_xattr_handler_map[] = 
{
 #ifdef CONFIG_EXT4_FS_SECURITY
        [EXT4_XATTR_INDEX_SECURITY]          = &ext4_xattr_security_handler,
 #endif
+#ifdef CONFIG_EXT4_FS_RICHACL
+       [EXT4_XATTR_INDEX_RICHACL]           = &ext4_richacl_xattr_handler,
+#endif
 };
 
 const struct xattr_handler *ext4_xattr_handlers[] = {
@@ -111,6 +114,9 @@ const struct xattr_handler *ext4_xattr_handlers[] = {
 #ifdef CONFIG_EXT4_FS_SECURITY
        &ext4_xattr_security_handler,
 #endif
+#ifdef CONFIG_EXT4_FS_RICHACL
+       &ext4_richacl_xattr_handler,
+#endif
        NULL
 };
 
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index ddc0957..f315493 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -98,6 +98,7 @@ struct ext4_xattr_ibody_find {
 extern const struct xattr_handler ext4_xattr_user_handler;
 extern const struct xattr_handler ext4_xattr_trusted_handler;
 extern const struct xattr_handler ext4_xattr_security_handler;
+extern const struct xattr_handler ext4_richacl_xattr_handler;
 
 #define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
 
-- 
2.4.3

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