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[209.85.220.73]) by mx.google.com with SMTPS id t4sor2420581pgp.86.2019.07.01.17.51.50 for (Google Transport Security); Mon, 01 Jul 2019 17:51:50 -0700 (PDT) Received-SPF: pass (google.com: domain of 3pqoaxqokcfu41aelyheaf3bb381.zb985ahk-997ixz7.be3@flex--henryburns.bounces.google.com designates 209.85.220.73 as permitted sender) client-ip=209.85.220.73; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=ODdYbhrZ; spf=pass (google.com: domain of 3pqoaxqokcfu41aelyheaf3bb381.zb985ahk-997ixz7.be3@flex--henryburns.bounces.google.com designates 209.85.220.73 as permitted sender) smtp.mailfrom=3pqoaXQoKCFU41AELyHEAF3BB381.zB985AHK-997Ixz7.BE3@flex--henryburns.bounces.google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=fQRHpcnZQgmJ5EVYhy+Qqag9BuKV3GgR0RmH9DgVc30=; b=ODdYbhrZxLaj82QT81sQFex0PsUNmi7pkBfxxjI2BAqvUgbT1v5TtvMslVPTu/mUMp MnvG9TO9zNsxpUFKLqftjjjMTJsVYPqjIOmm2oNV41LiRHkjdcA3EKJ4EbQnS5uiPQfM Zpt0Pu7BsCzYycwnA83E8hGzxksbyCLMMp8GvRlzJdjwyfjNUsSW86ZNgnExlTFI0clR lrPk2JAuiLERvcNdFXCFwo9a7auujyK/+AtWsKFveHTrcIEjmeUqdfcQw+WmGs8kjTjm NrDfELXrRp/baVJbjHvlkgBpNBTz6IjR4P+aaniPxlvNq/kvztmSoJu5gT1ZU+y8IjCW UEJQ== X-Google-Smtp-Source: APXvYqzXhknzPhp8ywA8IJFv6X8bS3qEb+pGQJo6CDssSNJBkI8XUGFWLMs249ByEsdnkPkZUi5H4YIv/jBLv21t X-Received: by 2002:a65:44c8:: with SMTP id g8mr27400341pgs.443.1562028710037; Mon, 01 Jul 2019 17:51:50 -0700 (PDT) Date: Mon, 1 Jul 2019 17:51:22 -0700 Message-Id: <20190702005122.41036-1-henryburns@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH v2] mm/z3fold.c: Lock z3fold page before __SetPageMovable() From: Henry Burns To: Vitaly Wool , Andrew Morton Cc: Vitaly Vul , Mike Rapoport , Xidong Wang , Shakeel Butt , Jonathan Adams , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Henry Burns Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: __SetPageMovable() expects it's page to be locked, but z3fold.c doesn't lock the page. Following zsmalloc.c's example we call trylock_page() and unlock_page(). Also makes z3fold_page_migrate() assert that newpage is passed in locked, as documentation. Signed-off-by: Henry Burns Suggested-by: Vitaly Wool --- Changelog since v1: - Added an if statement around WARN_ON(trylock_page(page)) to avoid unlocking a page locked by a someone else. mm/z3fold.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/z3fold.c b/mm/z3fold.c index e174d1549734..6341435b9610 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -918,7 +918,10 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp, set_bit(PAGE_HEADLESS, &page->private); goto headless; } - __SetPageMovable(page, pool->inode->i_mapping); + if (!WARN_ON(!trylock_page(page))) { + __SetPageMovable(page, pool->inode->i_mapping); + unlock_page(page); + } z3fold_page_lock(zhdr); found: @@ -1325,6 +1328,7 @@ 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); -- 2.22.0.410.gd8fdbe21b5-goog