[PATCH v10 20/46] ext4: Add richacl support

From: Andreas Gruenbacher
Date: Sun Oct 11 2015 - 19:01:38 EST

From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>

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: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/ext4/Kconfig | 11 +++++
fs/ext4/Makefile | 1 +
fs/ext4/file.c | 3 ++
fs/ext4/ialloc.c | 7 ++-
fs/ext4/inode.c | 10 +++--
fs/ext4/namei.c | 5 +++
fs/ext4/richacl.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/richacl.h | 43 ++++++++++++++++++
fs/ext4/xattr.c | 7 +++
9 files changed, 212 insertions(+), 4 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 47728da..3ec0843 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -22,6 +22,17 @@ config EXT3_FS_POSIX_ACL
This config option is here only for backward compatibility. ext3
filesystem is now handled by the ext4 driver.

+config EXT4_FS_RICHACL
+ bool "Ext4 Rich Access Control Lists (EXPERIMENTAL)"
+ depends on EXT4_FS
+ select FS_RICHACL
+ help
+ Richacls are an implementation of NFSv4 ACLs, extended by file masks
+ to cleanly integrate into the POSIX file permission model. To learn
+ more about them, see http://www.bestbits.at/richacl/.
+
+ If you don't know what Richacls are, say N.
+
config EXT3_FS_SECURITY
bool "Ext3 Security Labels"
depends on EXT3_FS
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/file.c b/fs/ext4/file.c
index 113837e..a03b4a5 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -30,6 +30,7 @@
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
+#include "richacl.h"

/*
* Called when an inode is released. Note that this is different
@@ -719,6 +720,8 @@ const struct inode_operations ext4_file_inode_operations = {
.removexattr = generic_removexattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
+ .get_richacl = ext4_get_richacl,
+ .set_richacl = ext4_set_richacl,
.fiemap = ext4_fiemap,
};

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 619bfc1..f279725 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>

@@ -1052,7 +1053,11 @@ 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_acl(handle, inode, dir);
+
if (err)
goto fail_free_drop;

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 612fbcf..d8a48a3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -42,6 +42,7 @@
#include "xattr.h"
#include "acl.h"
#include "truncate.h"
+#include "richacl.h"

#include <trace/events/ext4.h>

@@ -4805,9 +4806,12 @@ 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 = richacl_chmod(inode, inode->i_mode);
+ 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 9f61e76..9b6e8b9 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>
/*
@@ -3854,6 +3855,8 @@ const struct inode_operations ext4_dir_inode_operations = {
.removexattr = generic_removexattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
+ .get_richacl = ext4_get_richacl,
+ .set_richacl = ext4_set_richacl,
.fiemap = ext4_fiemap,
};

@@ -3865,4 +3868,6 @@ const struct inode_operations ext4_special_inode_operations = {
.removexattr = generic_removexattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
+ .get_richacl = ext4_get_richacl,
+ .set_richacl = ext4_set_richacl,
};
diff --git a/fs/ext4/richacl.c b/fs/ext4/richacl.c
new file mode 100644
index 0000000..b46ac60
--- /dev/null
+++ b/fs/ext4/richacl.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright IBM Corporation, 2010
+ * Copyright (C) 2015 Red Hat, Inc.
+ * Author Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
+ *
+ * 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;
+
+ 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;
+ umode_t mode = inode->i_mode;
+ int retval;
+
+ if (acl) {
+ if (richacl_equiv_mode(acl, &mode) == 0) {
+ inode->i_ctime = ext4_current_time(inode);
+ inode->i_mode = mode;
+ ext4_mark_inode_dirty(handle, inode);
+ acl = NULL;
+ }
+ }
+ if (acl) {
+ void *value;
+ size_t size = richacl_xattr_size(acl);
+
+ mode &= ~S_IRWXUGO;
+ mode |= richacl_masks_to_mode(acl);
+
+ value = kmalloc(size, GFP_NOFS);
+ if (!value)
+ return -ENOMEM;
+ richacl_to_xattr(&init_user_ns, acl, value, size);
+ inode->i_mode = mode;
+ retval = ext4_xattr_set_handle(handle, inode, name_index, "",
+ value, size, 0);
+ kfree(value);
+ } else
+ retval = ext4_xattr_set_handle(handle, inode, name_index, "",
+ NULL, 0, 0);
+ if (!retval)
+ set_cached_richacl(inode, acl);
+
+ return retval;
+}
+
+int
+ext4_set_richacl(struct inode *inode, struct richacl *acl)
+{
+ handle_t *handle;
+ int retval, retries = 0;
+
+retry:
+ handle = ext4_journal_start(inode, EXT4_HT_XATTR,
+ ext4_jbd2_credits_xattr(inode));
+ 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;
+ return retval;
+}
+
+int
+ext4_init_richacl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+ struct richacl *acl = richacl_create(&inode->i_mode, 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;
+}
diff --git a/fs/ext4/richacl.h b/fs/ext4/richacl.h
new file mode 100644
index 0000000..fc7826f
--- /dev/null
+++ b/fs/ext4/richacl.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright IBM Corporation, 2010
+ * Copyright (C) 2015 Red Hat, Inc.
+ * Author Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
+ *
+ * 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_set_richacl(struct inode *, struct richacl *);
+
+extern int ext4_init_richacl(handle_t *, struct inode *, struct inode *);
+
+#else /* CONFIG_EXT4_FS_RICHACL */
+
+#define EXT4_IS_RICHACL(inode) (0)
+#define ext4_get_richacl NULL
+#define ext4_set_richacl NULL
+
+static inline int
+ext4_init_richacl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+ return 0;
+}
+
+#endif /* CONFIG_EXT4_FS_RICHACL */
+#endif /* __FS_EXT4_RICHACL_H */
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 16e28c0..4d79adb 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -55,6 +55,7 @@
#include <linux/slab.h>
#include <linux/mbcache.h>
#include <linux/quotaops.h>
+#include <linux/richacl_xattr.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"
@@ -99,6 +100,9 @@ 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] = &richacl_xattr_handler,
+#endif
};

const struct xattr_handler *ext4_xattr_handlers[] = {
@@ -111,6 +115,9 @@ const struct xattr_handler *ext4_xattr_handlers[] = {
#ifdef CONFIG_EXT4_FS_SECURITY
&ext4_xattr_security_handler,
#endif
+#ifdef CONFIG_EXT4_FS_RICHACL
+ &richacl_xattr_handler,
+#endif
NULL
};

--
2.5.0

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