Commit 810481a2 authored Jul 11, 2019 by Henry Burns Committed by Linus Torvalds Jul 12, 2019

mm/z3fold.c: lock z3fold page before __SetPageMovable()

Following zsmalloc.c's example we call trylock_page() and unlock_page().
Also make z3fold_page_migrate() assert that newpage is passed in locked,
as per the documentation.

[akpm@linux-foundation.org: fix trylock_page return value test, per Shakeel]
Link: http://lkml.kernel.org/r/20190702005122.41036-1-henryburns@google.com
Link: http://lkml.kernel.org/r/20190702233538.52793-1-henryburns@google.com


Signed-off-by: Henry Burns <henryburns@google.com>
Suggested-by: Vitaly Wool <vitalywool@gmail.com>
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Xidong Wang <wangxidong_97@163.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent dd923990

mm/z3fold.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -924,7 +924,16 @@ retry:
		set_bit(PAGE_HEADLESS, &page->private);
		goto headless;
		}
		if (can_sleep) {
		lock_page(page);
		__SetPageMovable(page, pool->inode->i_mapping);
		unlock_page(page);
		} else {
		if (trylock_page(page)) {
		__SetPageMovable(page, pool->inode->i_mapping);
		unlock_page(page);
		}
		}
		z3fold_page_lock(zhdr);

		found:
		@@ -1331,6 +1340,7 @@ static int z3fold_page_migrate(struct address_space mapping, struct page newpa

		VM_BUG_ON_PAGE(!PageMovable(page), page);
		VM_BUG_ON_PAGE(!PageIsolated(page), page);
		VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);

		zhdr = page_address(page);
		pool = zhdr_to_pool(zhdr);

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