On Fri, Nov 30, 2018 at 10:42 PM Darrick J. Wong <darrick.wong@xxxxxxxxxx> wrote: > > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > In overlayfs, ovl_remap_file_range calls vfs_clone_file_range on the > lower filesystem's inode, passing through whatever remap flags it got > from its caller. Since vfs_copy_file_range first tries a filesystem's > remap function with REMAP_FILE_CAN_SHORTEN, this can get passed through > to the second vfs_copy_file_range call, which isn't an issue. > Remove the WARN_ON because it's unnecessary. > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > --- > fs/read_write.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/fs/read_write.c b/fs/read_write.c > index 4dae0399c75a..2d9fed57e7dd 100644 > --- a/fs/read_write.c > +++ b/fs/read_write.c > @@ -1956,8 +1956,6 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, > struct inode *inode_out = file_inode(file_out); > loff_t ret; > > - WARN_ON_ONCE(remap_flags); > - WARN_ON_ONCE(remap_flags & ~REMAP_FILE_ADVISORY); We still do not want anyone to call do_clone_file_range(..., REMAP_FILE_DEDUP) If we had more users of the overloaded interface, we need to do: WARN_ON_ONCE((remap_flags & REMAP_FILE_OP_MASK) == REMAP_FILE_OP_CLONE); With the minor fix, you can add: Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx> Thanks, Amir.