From e9adcfecf572fcfaa9f8525904cf49c709974f73 Mon Sep 17 00:00:00 2001 From: Mike Kravetz Date: Tue, 3 Jan 2023 16:27:32 -0800 Subject: 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/20221114235507.294320-2-mike.kravetz@oracle.com/ Link: https://lkml.kernel.org/r/20230104002732.232573-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz Suggested-by: Peter Xu Acked-by: Michal Hocko Acked-by: Peter Xu Acked-by: Heiko Carstens [s390] Reviewed-by: Christoph Hellwig Cc: Christian Borntraeger Cc: Christian Brauner Cc: Dave Hansen Cc: David Hildenbrand Cc: Eric Dumazet Cc: Matthew Wilcox Cc: Michael Ellerman Cc: Nadav Amit Cc: Palmer Dabbelt Cc: Rik van Riel Cc: Vlastimil Babka Cc: Will Deacon Signed-off-by: Andrew Morton --- net/ipv4/tcp.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net/ipv4/tcp.c') 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 { -- cgit