This is a fairly plain acl implementation that stores the posix acls
into xattrs
Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxx>
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
new file mode 100644
index 0000000..1d53b62
--- /dev/null
+++ b/fs/btrfs/acl.c
@@ -0,0 +1,351 @@
+/*
+ * Copyright (C) 2007 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/sched.h>
+
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "xattr.h"
+
+#ifdef CONFIG_FS_POSIX_ACL
+
+static void btrfs_update_cached_acl(struct inode *inode,
+ struct posix_acl **p_acl,
+ struct posix_acl *acl)
+{
+ spin_lock(&inode->i_lock);
+ if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
+ posix_acl_release(*p_acl);
+ *p_acl = posix_acl_dup(acl);
+ spin_unlock(&inode->i_lock);
+}
+
+static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+{
+ int size;
+ const char *name;
+ char *value = NULL;
+ struct posix_acl *acl = NULL, **p_acl;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = POSIX_ACL_XATTR_ACCESS;
+ p_acl = &BTRFS_I(inode)->i_acl;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = POSIX_ACL_XATTR_DEFAULT;
+ p_acl = &BTRFS_I(inode)->i_default_acl;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ spin_lock(&inode->i_lock);
+ if (*p_acl != BTRFS_ACL_NOT_CACHED)
+ acl = posix_acl_dup(*p_acl);
+ spin_unlock(&inode->i_lock);
+
+ if (acl)
+ return acl;
+
+
+ size = __btrfs_getxattr(inode, name, "", 0);
+ if (size > 0) {
+ value = kzalloc(size, GFP_NOFS);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ size = __btrfs_getxattr(inode, name, value, size);
+ if (size > 0) {
+ acl = posix_acl_from_xattr(value, size);
+ btrfs_update_cached_acl(inode, p_acl, acl);
+ }
+ kfree(value);
+ } else if (size == -ENOENT) {
+ acl = NULL;
+ btrfs_update_cached_acl(inode, p_acl, acl);
+ }
+
+ return acl;
+}
+
+static int btrfs_xattr_get_acl(struct inode *inode, int type,
+ void *value, size_t size)
+{
+ struct posix_acl *acl;
+ int ret = 0;
+
+ acl = btrfs_get_acl(inode, type);
+
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+ ret = posix_acl_to_xattr(acl, value, size);
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+/*
+ * Needs to be called with fs_mutex held
+ */
+static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int ret, size = 0;
+ const char *name;
+ struct posix_acl **p_acl;
+ char *value = NULL;
+ mode_t mode;
+
+ if (acl) {
+ ret = posix_acl_valid(acl);
+ if (ret < 0)
+ return ret;
+ ret = 0;
+ }
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ mode = inode->i_mode;
+ ret = posix_acl_equiv_mode(acl, &mode);
+ if (ret < 0)
+ return ret;
+ ret = 0;
+ inode->i_mode = mode;
+ name = POSIX_ACL_XATTR_ACCESS;
+ p_acl = &BTRFS_I(inode)->i_acl;
+ break;
+ case ACL_TYPE_DEFAULT:
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EINVAL : 0;
+ name = POSIX_ACL_XATTR_DEFAULT;
+ p_acl = &BTRFS_I(inode)->i_default_acl;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ size = posix_acl_xattr_size(acl->a_count);
+ value = kmalloc(size, GFP_NOFS);
+ if (!value) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = posix_acl_to_xattr(acl, value, size);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = __btrfs_setxattr(inode, name, value, size, 0);
+
+out:
+ kfree(value);
+
+ if (!ret)
+ btrfs_update_cached_acl(inode, p_acl, acl);
+
+ return ret;
+}
+
+static int btrfs_xattr_set_acl(struct inode *inode, int type,
+ const void *value, size_t size)
+{
+ int ret = 0;
+ struct posix_acl *acl = NULL;
+
+ if (value) {
+ acl = posix_acl_from_xattr(value, size);
+ if (acl == NULL) {
+ value = NULL;
+ size = 0;
+ } else if (IS_ERR(acl)) {
+ return PTR_ERR(acl);
+ }
+ }
+
+ ret = btrfs_set_acl(inode, acl, type);
+
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+
+static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
+ void *value, size_t size)
+{
+ return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
+ void *value, size_t size)
+{
+ return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+ struct posix_acl *acl;
+ int error = -EAGAIN;
+
+ acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl) {
+ error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ }
+
+ return error;
+}
+
+/*
+ * btrfs_init_acl is already generally called under fs_mutex, so the locking
+ * stuff has been fixed to work with that. If the locking stuff changes, we
+ * need to re-evaluate the acl locking stuff.
+ */
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+ struct posix_acl *acl = NULL;
+ int ret = 0;
+
+ /* this happens with subvols */
+ if (!dir)
+ return 0;
+
+ if (!S_ISLNK(inode->i_mode)) {
+ if (IS_POSIXACL(dir)) {
+ acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ }
+
+ if (!acl)
+ inode->i_mode &= ~current->fs->umask;
+ }
+
+ if (IS_POSIXACL(dir) && acl) {
+ struct posix_acl *clone;
+ mode_t mode;
+
+ if (S_ISDIR(inode->i_mode)) {
+ ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
+ if (ret)
+ goto failed;
+ }
+ clone = posix_acl_clone(acl, GFP_NOFS);
+ ret = -ENOMEM;
+ if (!clone)
+ goto failed;
+
+ mode = inode->i_mode;
+ ret = posix_acl_create_masq(clone, &mode);
+ if (ret >= 0) {
+ inode->i_mode = mode;
+ if (ret > 0) {
+ /* we need an acl */
+ ret = btrfs_set_acl(inode, clone,
+ ACL_TYPE_ACCESS);
+ }
+ }
+ }
+failed:
+ posix_acl_release(acl);
+
+ return ret;
+}
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+ struct posix_acl *acl, *clone;
+ int ret = 0;
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ if (!IS_POSIXACL(inode))
+ return 0;
+
+ acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+ if (IS_ERR(acl) || !acl)
+ return PTR_ERR(acl);
+
+ clone = posix_acl_clone(acl, GFP_KERNEL);
+ posix_acl_release(acl);
+ if (!clone)
+ return -ENOMEM;
+
+ ret = posix_acl_chmod_masq(clone, inode->i_mode);
+ if (!ret)
+ ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
+
+ posix_acl_release(clone);
+
+ return ret;
+}
+
+struct xattr_handler btrfs_xattr_acl_default_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .get = btrfs_xattr_acl_default_get,
+ .set = btrfs_xattr_acl_default_set,
+};
+
+struct xattr_handler btrfs_xattr_acl_access_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .get = btrfs_xattr_acl_access_get,
+ .set = btrfs_xattr_acl_access_set,
+};
+
+#else /* CONFIG_FS_POSIX_ACL */
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+ return 0;
+}
+
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+ return 0;
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+ return 0;
+}
+
+#endif /* CONFIG_FS_POSIX_ACL */
--
1.6.0.2
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
