Richacl

fs/Kconfig

@@ -46,6 +46,9 @@ endif # BLOCK
 config FS_POSIX_ACL
 	def_bool n
 
+config FS_RICHACL
+	def_bool n
+
 config EXPORTFS
 	tristate
 

fs/Makefile

@@ -48,6 +48,8 @@ obj-$(CONFIG_NFS_COMMON)	+= nfs_common/
 obj-$(CONFIG_GENERIC_ACL)	+= generic_acl.o
 
 obj-$(CONFIG_FHANDLE)		+= fhandle.o
+obj-$(CONFIG_FS_RICHACL)	+= richacl.o
+richacl-y			:= richacl_base.o richacl_inode.o richacl_xattr.o
 
 obj-y				+= quota/
 

fs/attr.c

@@ -13,6 +13,57 @@
 #include <linux/fsnotify.h>
 #include <linux/fcntl.h>
 #include <linux/security.h>
+#include <linux/richacl.h>
+
+static int richacl_change_ok(struct inode *inode, int mask)
+{
+	if (!IS_RICHACL(inode))
+		return -EPERM;
+
+	if (inode->i_op->permission)
+		return inode->i_op->permission(inode, mask);
+	if (inode->i_op->get_richacl)
+		return check_richacl(inode, mask);
+	return -EPERM;
+}
+
+static bool inode_uid_change_ok(struct inode *inode, uid_t ia_uid)
+{
+	if (current_fsuid() == inode->i_uid && ia_uid == inode->i_uid)
+		return true;
+	if (current_fsuid() == ia_uid &&
+	    richacl_change_ok(inode, MAY_TAKE_OWNERSHIP) == 0)
+		return true;
+	if (capable(CAP_CHOWN))
+		return true;
+	return false;
+}
+
+static bool inode_gid_change_ok(struct inode *inode, gid_t ia_gid)
+{
+	int in_group = in_group_p(ia_gid);
+	if (current_fsuid() == inode->i_uid &&
+	    (in_group || ia_gid == inode->i_gid))
+		return true;
+	if (in_group && richacl_change_ok(inode, MAY_TAKE_OWNERSHIP) == 0)
+		return true;
+	if (capable(CAP_CHOWN))
+		return true;
+	return false;
+}
+
+static bool inode_owner_permitted_or_capable(struct inode *inode, int mask)
+{
+	struct user_namespace *ns = inode_userns(inode);
+
+	if (current_user_ns() == ns && current_fsuid() == inode->i_uid)
+		return true;
+	if (richacl_change_ok(inode, mask) == 0)
+		return true;
+	if (ns_capable(ns, CAP_FOWNER))
+		return true;
+	return false;
+}
 
 /**
  * inode_change_ok - check if attribute changes to an inode are allowed
@@ -26,7 +77,7 @@
  * Should be called as the first thing in ->setattr implementations,
  * possibly after taking additional locks.
  */
-int inode_change_ok(const struct inode *inode, struct iattr *attr)
+int inode_change_ok(struct inode *inode, struct iattr *attr)
 {
 	unsigned int ia_valid = attr->ia_valid;
 
@@ -45,21 +96,20 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
 		return 0;
 
 	/* Make sure a caller can chown. */
-	if ((ia_valid & ATTR_UID) &&
-	    (current_fsuid() != inode->i_uid ||
-	     attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
-		return -EPERM;
+	if (ia_valid & ATTR_UID) {
+		if (!inode_uid_change_ok(inode, attr->ia_uid))
+			return -EPERM;
+	}
 
 	/* Make sure caller can chgrp. */
-	if ((ia_valid & ATTR_GID) &&
-	    (current_fsuid() != inode->i_uid ||
-	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
-	    !capable(CAP_CHOWN))
-		return -EPERM;
+	if (ia_valid & ATTR_GID) {
+		if (!inode_gid_change_ok(inode, attr->ia_gid))
+			return -EPERM;
+	}
 
 	/* Make sure a caller can chmod. */
 	if (ia_valid & ATTR_MODE) {
-		if (!inode_owner_or_capable(inode))
+		if (!inode_owner_permitted_or_capable(inode, MAY_CHMOD))
 			return -EPERM;
 		/* Also check the setgid bit! */
 		if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
@@ -69,7 +119,7 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
 
 	/* Check for setting the inode time. */
 	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
-		if (!inode_owner_or_capable(inode))
+		if (!inode_owner_permitted_or_capable(inode, MAY_SET_TIMES))
 			return -EPERM;
 	}
 

fs/ext4/Kconfig

@@ -83,3 +83,18 @@ 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/kernel/debug/ext4/mballoc-debug"
+
+config EXT4_FS_RICHACL
+      bool "Ext4 Rich Access Control Lists (EXPERIMENTAL)"
+      depends on EXT4_FS_XATTR && EXPERIMENTAL
+      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

fs/ext4/Makefile

@@ -12,3 +12,4 @@ ext4-y	:= balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o page-io.o \
 ext4-$(CONFIG_EXT4_FS_XATTR)		+= xattr.o xattr_user.o xattr_trusted.o
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o
+ext4-$(CONFIG_EXT4_FS_RICHACL) 		+= richacl.o

fs/ext4/acl.c

@@ -131,15 +131,14 @@ ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
  *
  * inode->i_mutex: don't care
  */
-struct posix_acl *
-ext4_get_acl(struct inode *inode, int type)
+struct posix_acl *ext4_get_posix_acl(struct inode *inode, int type)
 {
 	int name_index;
 	char *value = NULL;
 	struct posix_acl *acl;
 	int retval;
 
-	if (!test_opt(inode->i_sb, POSIX_ACL))
+	if (!IS_POSIXACL(inode))
 		return NULL;
 
 	acl = get_cached_acl(inode, type);
@@ -248,15 +247,15 @@ ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 	int error = 0;
 
 	if (!S_ISLNK(inode->i_mode)) {
-		if (test_opt(dir->i_sb, POSIX_ACL)) {
-			acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT);
+		if (IS_POSIXACL(inode)) {
+			acl = ext4_get_posix_acl(dir, ACL_TYPE_DEFAULT);
 			if (IS_ERR(acl))
 				return PTR_ERR(acl);
 		}
 		if (!acl)
 			inode->i_mode &= ~current_umask();
 	}
-	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
+	if (IS_POSIXACL(inode) && acl) {
 		if (S_ISDIR(inode->i_mode)) {
 			error = ext4_set_acl(handle, inode,
 					     ACL_TYPE_DEFAULT, acl);
@@ -302,9 +301,9 @@ ext4_acl_chmod(struct inode *inode)
 
 	if (S_ISLNK(inode->i_mode))
 		return -EOPNOTSUPP;
-	if (!test_opt(inode->i_sb, POSIX_ACL))
+	if (!IS_POSIXACL(inode))
 		return 0;
-	acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
+	acl = ext4_get_posix_acl(inode, ACL_TYPE_ACCESS);
 	if (IS_ERR(acl) || !acl)
 		return PTR_ERR(acl);
 	error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
@@ -337,7 +336,7 @@ ext4_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
 {
 	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 
-	if (!test_opt(dentry->d_sb, POSIX_ACL))
+	if (!IS_POSIXACL(dentry->d_inode))
 		return 0;
 	if (list && size <= list_len)
 		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
@@ -350,7 +349,7 @@ ext4_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
 {
 	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 
-	if (!test_opt(dentry->d_sb, POSIX_ACL))
+	if (!IS_POSIXACL(dentry->d_inode))
 		return 0;
 	if (list && size <= list_len)
 		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
@@ -366,10 +365,10 @@ ext4_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
 
 	if (strcmp(name, "") != 0)
 		return -EINVAL;
-	if (!test_opt(dentry->d_sb, POSIX_ACL))
+	if (!IS_POSIXACL(dentry->d_inode))
 		return -EOPNOTSUPP;
 
-	acl = ext4_get_acl(dentry->d_inode, type);
+	acl = ext4_get_posix_acl(dentry->d_inode, type);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl == NULL)
@@ -391,7 +390,7 @@ ext4_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
 
 	if (strcmp(name, "") != 0)
 		return -EINVAL;
-	if (!test_opt(inode->i_sb, POSIX_ACL))
+	if (!IS_POSIXACL(dentry->d_inode))
 		return -EOPNOTSUPP;
 	if (!inode_owner_or_capable(inode))
 		return -EPERM;

fs/ext4/acl.h

@@ -54,13 +54,13 @@ 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);
+struct posix_acl *ext4_get_posix_acl(struct inode *inode, int type);
 extern int ext4_acl_chmod(struct inode *);
 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
 
 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
 #include <linux/sched.h>
-#define ext4_get_acl NULL
+#define ext4_get_posix_acl NULL
 
 static inline int
 ext4_acl_chmod(struct inode *inode)

fs/ext4/ext4.h

@@ -901,7 +901,6 @@ struct ext4_inode_info {
 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
-#define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */

fs/ext4/file.c

@@ -28,6 +28,7 @@
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "richacl.h"
 
 /*
  * Called when an inode is released. Note that this is different
@@ -301,7 +302,8 @@ const struct inode_operations ext4_file_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.get_acl	= ext4_get_acl,
+	.get_acl	= ext4_get_posix_acl,
+	.get_richacl	= ext4_get_richacl,
 	.fiemap		= ext4_fiemap,
 };
 

fs/ext4/ialloc.c

@@ -28,6 +28,7 @@
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "richacl.h"
 
 #include <trace/events/ext4.h>
 
@@ -1039,7 +1040,11 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode,
 	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;
 

fs/ext4/inode.c

@@ -44,6 +44,7 @@
 #include "acl.h"
 #include "ext4_extents.h"
 #include "truncate.h"
+#include "richacl.h"
 
 #include <trace/events/ext4.h>
 
@@ -3945,9 +3946,12 @@ 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 = ext4_acl_chmod(inode);
-
+	if (!rc && (ia_valid & ATTR_MODE)) {
+		if (EXT4_IS_RICHACL(inode))
+			rc = ext4_richacl_chmod(inode);
+		else
+			rc = ext4_acl_chmod(inode);
+	}
 err_out:
 	ext4_std_error(inode->i_sb, error);
 	if (!error)

fs/ext4/namei.c

@@ -39,6 +39,7 @@
 
 #include "xattr.h"
 #include "acl.h"
+#include "richacl.h"
 
 #include <trace/events/ext4.h>
 /*
@@ -2586,7 +2587,8 @@ const struct inode_operations ext4_dir_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.get_acl	= ext4_get_acl,
+	.get_acl	= ext4_get_posix_acl,
+	.get_richacl	= ext4_get_richacl,
 	.fiemap         = ext4_fiemap,
 };
 
@@ -2598,5 +2600,6 @@ const struct inode_operations ext4_special_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
-	.get_acl	= ext4_get_acl,
+	.get_acl	= ext4_get_posix_acl,
+	.get_richacl	= ext4_get_richacl,
 };