On Tue, 2019-06-18 at 23:24 -0700, Song Liu wrote:
> index 8563339041f6..bab8d9eef46c 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -790,7 +790,11 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
> void truncate_pagecache(struct inode *inode, loff_t newsize)
> {
> struct address_space *mapping = inode->i_mapping;
> - loff_t holebegin = round_up(newsize, PAGE_SIZE);
> + loff_t holebegin;
> +
> + /* if non-shmem file has thp, truncate the whole file */
> + if (filemap_nr_thps(mapping))
> + newsize = 0;
>
I don't get it. Sometimes truncate is used to
increase the size of a file, or to change it
to a non-zero size.
Won't forcing the newsize to zero break applications,
when the file is truncated to a different size than
they expect?
