ovl: add lsattr/chattr support

Implement FS_IOC_GETFLAGS and FS_IOC_SETFLAGS.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 58b37fe..7590e43 100644 (file)
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -8,6 +8,7 @@
 
 #include <linux/cred.h>
 #include <linux/file.h>
+#include <linux/mount.h>
 #include <linux/xattr.h>
 #include <linux/uio.h>
 #include "overlayfs.h"
@@ -309,6 +310,82 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
        return ret;
 }
 
+static long ovl_real_ioctl(struct file *file, unsigned int cmd,
+                          unsigned long arg)
+{
+       struct fd real;
+       const struct cred *old_cred;
+       long ret;
+
+       ret = ovl_real_fdget(file, &real);
+       if (ret)
+               return ret;
+
+       old_cred = ovl_override_creds(file_inode(file)->i_sb);
+       ret = vfs_ioctl(real.file, cmd, arg);
+       revert_creds(old_cred);
+
+       fdput(real);
+
+       return ret;
+}
+
+static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       long ret;
+       struct inode *inode = file_inode(file);
+
+       switch (cmd) {
+       case FS_IOC_GETFLAGS:
+               ret = ovl_real_ioctl(file, cmd, arg);
+               break;
+
+       case FS_IOC_SETFLAGS:
+               if (!inode_owner_or_capable(inode))
+                       return -EACCES;
+
+               ret = mnt_want_write_file(file);
+               if (ret)
+                       return ret;
+
+               ret = ovl_copy_up(file_dentry(file));
+               if (!ret) {
+                       ret = ovl_real_ioctl(file, cmd, arg);
+
+                       inode_lock(inode);
+                       ovl_copyflags(ovl_inode_real(inode), inode);
+                       inode_unlock(inode);
+               }
+
+               mnt_drop_write_file(file);
+               break;
+
+       default:
+               ret = -ENOTTY;
+       }
+
+       return ret;
+}
+
+static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
+                            unsigned long arg)
+{
+       switch (cmd) {
+       case FS_IOC32_GETFLAGS:
+               cmd = FS_IOC_GETFLAGS;
+               break;
+
+       case FS_IOC32_SETFLAGS:
+               cmd = FS_IOC_SETFLAGS;
+               break;
+
+       default:
+               return -ENOIOCTLCMD;
+       }
+
+       return ovl_ioctl(file, cmd, arg);
+}
+
 const struct file_operations ovl_file_operations = {
        .open           = ovl_open,
        .release        = ovl_release,
@@ -318,4 +395,6 @@ const struct file_operations ovl_file_operations = {
        .fsync          = ovl_fsync,
        .mmap           = ovl_mmap,
        .fallocate      = ovl_fallocate,
+       .unlocked_ioctl = ovl_ioctl,
+       .compat_ioctl   = ovl_compat_ioctl,
 };