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-rw-r--r--fs/btrfs/acl.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
new file mode 100644
index 000000000..548d6a547
--- /dev/null
+++ b/fs/btrfs/acl.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Red Hat. All rights reserved.
+ */
+
+#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 <linux/sched/mm.h>
+#include <linux/slab.h>
+
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "xattr.h"
+
+struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu)
+{
+ int size;
+ const char *name;
+ char *value = NULL;
+ struct posix_acl *acl;
+
+ if (rcu)
+ return ERR_PTR(-ECHILD);
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = XATTR_NAME_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = XATTR_NAME_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ size = btrfs_getxattr(inode, name, NULL, 0);
+ if (size > 0) {
+ value = kzalloc(size, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ size = btrfs_getxattr(inode, name, value, size);
+ }
+ if (size > 0)
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ else if (size == -ENODATA || size == 0)
+ acl = NULL;
+ else
+ acl = ERR_PTR(size);
+ kfree(value);
+
+ return acl;
+}
+
+int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
+ struct posix_acl *acl, int type)
+{
+ int ret, size = 0;
+ const char *name;
+ char *value = NULL;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = XATTR_NAME_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EINVAL : 0;
+ name = XATTR_NAME_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ unsigned int nofs_flag;
+
+ size = posix_acl_xattr_size(acl->a_count);
+ /*
+ * We're holding a transaction handle, so use a NOFS memory
+ * allocation context to avoid deadlock if reclaim happens.
+ */
+ nofs_flag = memalloc_nofs_save();
+ value = kmalloc(size, GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
+ if (!value) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+ if (ret < 0)
+ goto out;
+ }
+
+ if (trans)
+ ret = btrfs_setxattr(trans, inode, name, value, size, 0);
+ else
+ ret = btrfs_setxattr_trans(inode, name, value, size, 0);
+
+out:
+ kfree(value);
+
+ if (!ret)
+ set_cached_acl(inode, type, acl);
+
+ return ret;
+}
+
+int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+ struct posix_acl *acl, int type)
+{
+ int ret;
+ umode_t old_mode = inode->i_mode;
+
+ if (type == ACL_TYPE_ACCESS && acl) {
+ ret = posix_acl_update_mode(mnt_userns, inode,
+ &inode->i_mode, &acl);
+ if (ret)
+ return ret;
+ }
+ ret = __btrfs_set_acl(NULL, inode, acl, type);
+ if (ret)
+ inode->i_mode = old_mode;
+ return ret;
+}