ext4: bail early when clearing inode journal flag fails

[firefly-linux-kernel-4.4.55.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 77fd536106cba240ae734083d2ba329027e936ed..42df664e95e54a2148093c14fe1f1ce43b909f33 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4209,12 +4209,16 @@ SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
        bool should_retry = false;
        int error;
 
-       if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+       if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
                return -EINVAL;
 
-       if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE))
+       if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) &&
+           (flags & RENAME_EXCHANGE))
                return -EINVAL;
 
+       if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD))
+               return -EPERM;
+
 retry:
        from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
        if (IS_ERR(from)) {
@@ -4346,6 +4350,20 @@ SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newna
        return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
 }
 
+int vfs_whiteout(struct inode *dir, struct dentry *dentry)
+{
+       int error = may_create(dir, dentry);
+       if (error)
+               return error;
+
+       if (!dir->i_op->mknod)
+               return -EPERM;
+
+       return dir->i_op->mknod(dir, dentry,
+                               S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV);
+}
+EXPORT_SYMBOL(vfs_whiteout);
+
 int readlink_copy(char __user *buffer, int buflen, const char *link)
 {
        int len = PTR_ERR(link);