Re: [PATCH] iomap: Fix the write_count in iomap_add_to_ioend().

From: Matthew Wilcox
Date: Fri Aug 21 2020 - 09:32:03 EST


On Wed, Aug 19, 2020 at 03:58:41PM +0530, Anju T Sudhakar wrote:
> __bio_try_merge_page() may return same_page = 1 and merged = 0.
> This could happen when bio->bi_iter.bi_size + len > UINT_MAX.
> Handle this case in iomap_add_to_ioend() by incrementing write_count.

One of the patches I have pending ignores same_page by just using the
write_count as a byte count instead of a segment count. It's currently
mixed into this patch but needs to be separated.

http://git.infradead.org/users/willy/pagecache.git/commitdiff/0186d1dde949a458584c56b706fa8dfd252466ff

(another patch does the same thing to the read count).