@@ -49,7 +49,8 @@ obj-$(CONFIG_SYSCTL) += drop_caches.o
obj-$(CONFIG_FHANDLE) += fhandle.o
obj-$(CONFIG_FS_RICHACL) += richacl.o
-richacl-y := richacl_base.o richacl_inode.o richacl_xattr.o
+richacl-y := richacl_base.o richacl_inode.o \
+ richacl_xattr.o richacl_compat.o
obj-y += quota/
new file mode 100644
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2006, 2010 Novell, Inc.
+ * Copyright (C) 2015 Red Hat, Inc.
+ * Written by Andreas Gruenbacher <agruen@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/richacl_compat.h>
+
+/**
+ * richacl_prepare - allocate richacl being constructed
+ *
+ * Allocate a richacl which can hold @count entries but which is initially
+ * empty.
+ */
+struct richacl *richacl_prepare(struct richacl_alloc *alloc, unsigned int count)
+{
+ alloc->acl = richacl_alloc(count, GFP_KERNEL);
+ if (!alloc->acl)
+ return NULL;
+ alloc->acl->a_count = 0;
+ alloc->count = count;
+ return alloc->acl;
+}
+EXPORT_SYMBOL_GPL(richacl_prepare);
+
+/**
+ * richacl_delete_entry - delete an entry in an acl
+ * @alloc: acl and number of allocated entries
+ * @ace: an entry in @alloc->acl
+ *
+ * Updates @ace so that it points to the entry before the deleted entry
+ * on return. (When deleting the first entry, @ace will point to the
+ * (non-existent) entry before the first entry). This behavior is the
+ * expected behavior when deleting entries while forward iterating over
+ * an acl.
+ */
+void
+richacl_delete_entry(struct richacl_alloc *alloc, struct richace **ace)
+{
+ void *end = alloc->acl->a_entries + alloc->acl->a_count;
+
+ memmove(*ace, *ace + 1, end - (void *)(*ace + 1));
+ (*ace)--;
+ alloc->acl->a_count--;
+}
+EXPORT_SYMBOL_GPL(richacl_delete_entry);
+
+/**
+ * richacl_insert_entry - insert an entry in an acl
+ * @alloc: acl and number of allocated entries
+ * @ace: entry before which the new entry shall be inserted
+ *
+ * Insert a new entry in @alloc->acl at position @ace and zero-initialize
+ * it. This may require reallocating @alloc->acl.
+ */
+int
+richacl_insert_entry(struct richacl_alloc *alloc, struct richace **ace)
+{
+ struct richacl *acl = alloc->acl;
+ unsigned int index = *ace - acl->a_entries;
+ size_t tail_size = (acl->a_count - index) * sizeof(struct richace);
+
+ if (alloc->count == acl->a_count) {
+ size_t new_size = sizeof(struct richacl) +
+ (acl->a_count + 1) * sizeof(struct richace);
+
+ acl = krealloc(acl, new_size, GFP_KERNEL);
+ if (!acl)
+ return -1;
+ *ace = acl->a_entries + index;
+ alloc->acl = acl;
+ alloc->count++;
+ }
+
+ memmove(*ace + 1, *ace, tail_size);
+ memset(*ace, 0, sizeof(**ace));
+ acl->a_count++;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(richacl_insert_entry);
+
+/**
+ * richacl_append_entry - append an entry to an acl
+ * @alloc: acl and number of allocated entries
+ *
+ * This may require reallocating @alloc->acl.
+ */
+struct richace *richacl_append_entry(struct richacl_alloc *alloc)
+{
+ struct richacl *acl = alloc->acl;
+ struct richace *ace = acl->a_entries + acl->a_count;
+
+ if (alloc->count > alloc->acl->a_count) {
+ acl->a_count++;
+ return ace;
+ }
+ return richacl_insert_entry(alloc, &ace) ? NULL : ace;
+}
+EXPORT_SYMBOL_GPL(richacl_append_entry);
+
+/**
+ * richace_change_mask - set the mask of @ace to @mask
+ * @alloc: acl and number of allocated entries
+ * @ace: entry to modify
+ * @mask: new mask for @ace
+ *
+ * If @ace is inheritable, a inherit-only ace is inserted before @ace which
+ * includes the inheritable permissions of @ace and the inheritance flags of
+ * @ace are cleared before changing the mask.
+ *
+ * If @mask is 0, the original ace is turned into an inherit-only entry if
+ * there are any inheritable permissions, and removed otherwise.
+ *
+ * The returned @ace points to the modified or inserted effective-only acl
+ * entry if that entry exists, to the entry that has become inheritable-only,
+ * or else to the previous entry in the acl.
+ */
+static int
+richace_change_mask(struct richacl_alloc *alloc, struct richace **ace,
+ unsigned int mask)
+{
+ if (mask && (*ace)->e_mask == mask)
+ (*ace)->e_flags &= ~RICHACE_INHERIT_ONLY_ACE;
+ else if (mask & ~RICHACE_POSIX_ALWAYS_ALLOWED) {
+ if (richace_is_inheritable(*ace)) {
+ if (richacl_insert_entry(alloc, ace))
+ return -1;
+ richace_copy(*ace, *ace + 1);
+ (*ace)->e_flags |= RICHACE_INHERIT_ONLY_ACE;
+ (*ace)++;
+ (*ace)->e_flags &= ~RICHACE_INHERITANCE_FLAGS |
+ RICHACE_INHERITED_ACE;
+ }
+ (*ace)->e_mask = mask;
+ } else {
+ if (richace_is_inheritable(*ace))
+ (*ace)->e_flags |= RICHACE_INHERIT_ONLY_ACE;
+ else
+ richacl_delete_entry(alloc, ace);
+ }
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ * Written by Andreas Gruenbacher <agruenba@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * 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.
+ */
+
+#ifndef __RICHACL_COMPAT_H
+#define __RICHACL_COMPAT_H
+
+#include <linux/richacl.h>
+
+/**
+ * struct richacl_alloc - remember how many entries are actually allocated
+ * @acl: acl with a_count <= @count
+ * @count: the actual number of entries allocated in @acl
+ *
+ * We pass around this structure while modifying an acl so that we do
+ * not have to reallocate when we remove existing entries followed by
+ * adding new entries.
+ */
+struct richacl_alloc {
+ struct richacl *acl;
+ unsigned int count;
+};
+
+struct richacl *richacl_prepare(struct richacl_alloc *, unsigned int);
+struct richace *richacl_append_entry(struct richacl_alloc *);
+int richacl_insert_entry(struct richacl_alloc *, struct richace **);
+void richacl_delete_entry(struct richacl_alloc *, struct richace **);
+
+#endif /* __RICHACL_COMPAT_H */