introduce cloning of fs_context
new primitive: vfs_dup_fs_context(). Comes with fs_context
method (->dup()) for copying the filesystem-specific parts
of fs_context, along with LSM one (->fs_context_dup()) for
doing the same to LSM parts.
[needs better commit message, and change of Author:, anyway]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5f93c4f..03176f6 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -647,6 +647,54 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts)
return -EINVAL;
}
+/**
+ * smack_fs_context_dup - Duplicate the security data on fs_context duplication
+ * @fc: The new filesystem context.
+ * @src_fc: The source filesystem context being duplicated.
+ *
+ * Returns 0 on success or -ENOMEM on error.
+ */
+static int smack_fs_context_dup(struct fs_context *fc,
+ struct fs_context *src_fc)
+{
+ struct smack_mnt_opts *dst, *src = src_fc->security;
+
+ if (!src)
+ return 0;
+
+ fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
+ if (!fc->security)
+ return -ENOMEM;
+ dst = fc->security;
+
+ if (src->fsdefault) {
+ dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL);
+ if (!dst->fsdefault)
+ return -ENOMEM;
+ }
+ if (src->fsfloor) {
+ dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL);
+ if (!dst->fsfloor)
+ return -ENOMEM;
+ }
+ if (src->fshat) {
+ dst->fshat = kstrdup(src->fshat, GFP_KERNEL);
+ if (!dst->fshat)
+ return -ENOMEM;
+ }
+ if (src->fsroot) {
+ dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL);
+ if (!dst->fsroot)
+ return -ENOMEM;
+ }
+ if (src->fstransmute) {
+ dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL);
+ if (!dst->fstransmute)
+ return -ENOMEM;
+ }
+ return 0;
+}
+
static const struct fs_parameter_spec smack_param_specs[] = {
fsparam_string("fsdefault", Opt_fsdefault),
fsparam_string("fsfloor", Opt_fsfloor),
@@ -4626,6 +4674,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
LSM_HOOK_INIT(syslog, smack_syslog),
+ LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),