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, 4 insertions, 3 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c567d5e8053e..f713c0422f0f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2092,7 +2092,7 @@ static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma,
 		maybe_zap_len = total_bytes_to_map -  /* All bytes to map */
 				*length + /* Mapped or pending */
 				(pages_remaining * PAGE_SIZE); /* Failed map. */
-		zap_page_range(vma, *address, maybe_zap_len);
+		zap_page_range_single(vma, *address, maybe_zap_len, NULL);
 		err = 0;
 	}
 
@@ -2100,7 +2100,7 @@ static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma,
 		unsigned long leftover_pages = pages_remaining;
 		int bytes_mapped;
 
-		/* We called zap_page_range, try to reinsert. */
+		/* We called zap_page_range_single, try to reinsert. */
 		err = vm_insert_pages(vma, *address,
 				      pending_pages,
 				      &pages_remaining);
@@ -2234,7 +2234,8 @@ static int tcp_zerocopy_receive(struct sock *sk,
 	total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1);
 	if (total_bytes_to_map) {
 		if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT))
-			zap_page_range(vma, address, total_bytes_to_map);
+			zap_page_range_single(vma, address, total_bytes_to_map,
+					      NULL);
 		zc->length = total_bytes_to_map;
 		zc->recv_skip_hint = 0;
 	} else {