mm: remove zap_page_range and create zap_vma_pages

zap_page_range was originally designed to unmap pages within an address
range that could span multiple vmas.  While working on [1], it was
discovered that all callers of zap_page_range pass a range entirely within
a single vma.  In addition, the mmu notification call within zap_page
range does not correctly handle ranges that span multiple vmas.  When
crossing a vma boundary, a new mmu_notifier_range_init/end call pair with
the new vma should be made.

Instead of fixing zap_page_range, do the following:
- Create a new routine zap_vma_pages() that will remove all pages within
  the passed vma.  Most users of zap_page_range pass the entire vma and
  can use this new routine.
- For callers of zap_page_range not passing the entire vma, instead call
  zap_page_range_single().
- Remove zap_page_range.

[1] https://lore.kernel.org/linux-mm/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Kravetz <[email protected]>
Suggested-by: Peter Xu <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Peter Xu <[email protected]>
Acked-by: Heiko Carstens <[email protected]>	[s390]
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 337cafe9978c..e91f94b3438b 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2690,7 +2690,7 @@ void folio_account_cleaned(struct folio *folio, struct bdi_writeback *wb)
  *
  * The caller must hold lock_page_memcg().  Most callers have the folio
  * locked.  A few have the folio blocked from truncation through other
- * means (eg zap_page_range() has it mapped and is holding the page table
+ * means (eg zap_vma_pages() has it mapped and is holding the page table
  * lock).  This can also be called from mark_buffer_dirty(), which I
  * cannot prove is always protected against truncate.
  */