Patch series "Three memory-failure fixes".

I've been looking at the memory-failure code and I believe I have found
three bugs that need fixing -- one going all the way back to 2010!  I'll
have more patches later to use folios more extensively but didn't want
these bugfixes to get caught up in that.


This patch (of 3):

Both collect_procs_anon() and collect_procs_file() iterate over the VMA
interval trees looking for a single pgoff, so it is wrong to look for the
pgoff of the head page as is currently done.  However, it is also wrong to
look at page->mapping of the precise page as this is invalid for tail
pages.  Clear up the confusion by passing both the folio and the precise
page to collect_procs().

Link: https://lkml.kernel.org/r/20231218135837.3310403-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231218135837.3310403-2-willy@infradead.org
Fixes: 415c64c1453a ("mm/memory-failure: split thp earlier in memory error handling")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>