hfsplus: implement POSIX ACLs support
Implement POSIX ACLs support in hfsplus driver.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/hfsplus/posix_acl.c b/fs/hfsplus/posix_acl.c
new file mode 100644
index 0000000..b609cc1
--- /dev/null
+++ b/fs/hfsplus/posix_acl.c
@@ -0,0 +1,274 @@
+/*
+ * linux/fs/hfsplus/posix_acl.c
+ *
+ * Vyacheslav Dubeyko <slava@dubeyko.com>
+ *
+ * Handler for Posix Access Control Lists (ACLs) support.
+ */
+
+#include "hfsplus_fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+struct posix_acl *hfsplus_get_posix_acl(struct inode *inode, int type)
+{
+ struct posix_acl *acl;
+ char *xattr_name;
+ char *value = NULL;
+ ssize_t size;
+
+ acl = get_cached_acl(inode, type);
+ if (acl != ACL_NOT_CACHED)
+ return acl;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ xattr_name = POSIX_ACL_XATTR_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ xattr_name = POSIX_ACL_XATTR_DEFAULT;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ size = __hfsplus_getxattr(inode, xattr_name, NULL, 0);
+
+ if (size > 0) {
+ value = (char *)hfsplus_alloc_attr_entry();
+ if (unlikely(!value))
+ return ERR_PTR(-ENOMEM);
+ size = __hfsplus_getxattr(inode, xattr_name, value, size);
+ }
+
+ if (size > 0)
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ else if (size == -ENODATA)
+ acl = NULL;
+ else
+ acl = ERR_PTR(size);
+
+ hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
+
+ if (!IS_ERR(acl))
+ set_cached_acl(inode, type, acl);
+
+ return acl;
+}
+
+static int hfsplus_set_posix_acl(struct inode *inode,
+ int type,
+ struct posix_acl *acl)
+{
+ int err;
+ char *xattr_name;
+ size_t size = 0;
+ char *value = NULL;
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ xattr_name = POSIX_ACL_XATTR_ACCESS;
+ if (acl) {
+ err = posix_acl_equiv_mode(acl, &inode->i_mode);
+ if (err < 0)
+ return err;
+ }
+ err = 0;
+ break;
+
+ case ACL_TYPE_DEFAULT:
+ xattr_name = POSIX_ACL_XATTR_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ size = posix_acl_xattr_size(acl->a_count);
+ if (unlikely(size > HFSPLUS_MAX_INLINE_DATA_SIZE))
+ return -ENOMEM;
+ value = (char *)hfsplus_alloc_attr_entry();
+ if (unlikely(!value))
+ return -ENOMEM;
+ err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+ if (unlikely(err < 0))
+ goto end_set_acl;
+ }
+
+ err = __hfsplus_setxattr(inode, xattr_name, value, size, 0);
+
+end_set_acl:
+ hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
+
+ if (!err)
+ set_cached_acl(inode, type, acl);
+
+ return err;
+}
+
+int hfsplus_init_posix_acl(struct inode *inode, struct inode *dir)
+{
+ int err = 0;
+ struct posix_acl *acl = NULL;
+
+ hfs_dbg(ACL_MOD,
+ "[%s]: ino %lu, dir->ino %lu\n",
+ __func__, inode->i_ino, dir->i_ino);
+
+ if (S_ISLNK(inode->i_mode))
+ return 0;
+
+ acl = hfsplus_get_posix_acl(dir, ACL_TYPE_DEFAULT);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+
+ if (acl) {
+ if (S_ISDIR(inode->i_mode)) {
+ err = hfsplus_set_posix_acl(inode,
+ ACL_TYPE_DEFAULT,
+ acl);
+ if (unlikely(err))
+ goto init_acl_cleanup;
+ }
+
+ err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
+ if (unlikely(err < 0))
+ return err;
+
+ if (err > 0)
+ err = hfsplus_set_posix_acl(inode,
+ ACL_TYPE_ACCESS,
+ acl);
+ } else
+ inode->i_mode &= ~current_umask();
+
+init_acl_cleanup:
+ posix_acl_release(acl);
+ return err;
+}
+
+int hfsplus_posix_acl_chmod(struct inode *inode)
+{
+ int err;
+ struct posix_acl *acl;
+
+ hfs_dbg(ACL_MOD, "[%s]: ino %lu\n", __func__, inode->i_ino);
+
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ acl = hfsplus_get_posix_acl(inode, ACL_TYPE_ACCESS);
+ if (IS_ERR(acl) || !acl)
+ return PTR_ERR(acl);
+
+ err = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
+ if (unlikely(err))
+ return err;
+
+ err = hfsplus_set_posix_acl(inode, ACL_TYPE_ACCESS, acl);
+ posix_acl_release(acl);
+ return err;
+}
+
+static int hfsplus_xattr_get_posix_acl(struct dentry *dentry,
+ const char *name,
+ void *buffer,
+ size_t size,
+ int type)
+{
+ int err = 0;
+ struct posix_acl *acl;
+
+ hfs_dbg(ACL_MOD,
+ "[%s]: ino %lu, buffer %p, size %zu, type %#x\n",
+ __func__, dentry->d_inode->i_ino, buffer, size, type);
+
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+
+ acl = hfsplus_get_posix_acl(dentry->d_inode, type);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+
+ err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+ posix_acl_release(acl);
+
+ return err;
+}
+
+static int hfsplus_xattr_set_posix_acl(struct dentry *dentry,
+ const char *name,
+ const void *value,
+ size_t size,
+ int flags,
+ int type)
+{
+ int err = 0;
+ struct inode *inode = dentry->d_inode;
+ struct posix_acl *acl = NULL;
+
+ hfs_dbg(ACL_MOD,
+ "[%s]: ino %lu, value %p, size %zu, flags %#x, type %#x\n",
+ __func__, inode->i_ino, value, size, flags, type);
+
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+
+ if (!inode_owner_or_capable(inode))
+ return -EPERM;
+
+ if (value) {
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ else if (acl) {
+ err = posix_acl_valid(acl);
+ if (err)
+ goto end_xattr_set_acl;
+ }
+ }
+
+ err = hfsplus_set_posix_acl(inode, type, acl);
+
+end_xattr_set_acl:
+ posix_acl_release(acl);
+ return err;
+}
+
+static size_t hfsplus_xattr_list_posix_acl(struct dentry *dentry,
+ char *list,
+ size_t list_size,
+ const char *name,
+ size_t name_len,
+ int type)
+{
+ /*
+ * This method is not used.
+ * It is used hfsplus_listxattr() instead of generic_listxattr().
+ */
+ return -EOPNOTSUPP;
+}
+
+const struct xattr_handler hfsplus_xattr_acl_access_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .flags = ACL_TYPE_ACCESS,
+ .list = hfsplus_xattr_list_posix_acl,
+ .get = hfsplus_xattr_get_posix_acl,
+ .set = hfsplus_xattr_set_posix_acl,
+};
+
+const struct xattr_handler hfsplus_xattr_acl_default_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .flags = ACL_TYPE_DEFAULT,
+ .list = hfsplus_xattr_list_posix_acl,
+ .get = hfsplus_xattr_get_posix_acl,
+ .set = hfsplus_xattr_set_posix_acl,
+};