Comment # 8 on bug 1049599 from GuoQing Jiang

I suspect the below commit may help:

md: remove 'idx' from 'struct resync_pages'

bio_add_page() won't fail for resync bio, and the page index for each
bio is same, so remove it.

More importantly the 'idx' of 'struct resync_pages' is initialized in
mempool allocator function, the current way is wrong since mempool is
only responsible for allocation, we can't use that for initialization.

Suggested-by: NeilBrown <neilb@suse.com>
Reported-by: NeilBrown <neilb@suse.com>
Fixes: f0250618361d(md: raid10: don't use bio's vec table to manage resync
pages)
Fixes: 98d30c5812c3(md: raid1: don't use bio's vec table to manage resync
pages)
Signed-off-by: Ming Lei <ming.lei@redhat.com>