From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id 825A16B0007 for ; Mon, 9 Apr 2018 19:05:44 -0400 (EDT) Received: by mail-qt0-f199.google.com with SMTP id u9so7112803qtg.2 for ; Mon, 09 Apr 2018 16:05:44 -0700 (PDT) Received: from userp2130.oracle.com (userp2130.oracle.com. [156.151.31.86]) by mx.google.com with ESMTPS id p57si1733947qtf.335.2018.04.09.16.05.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 09 Apr 2018 16:05:43 -0700 (PDT) From: Mike Kravetz Subject: [PATCH v3 1/3] mm/shmem: add __rcu annotations and properly deref radix entry Date: Mon, 9 Apr 2018 16:05:03 -0700 Message-Id: <20180409230505.18953-2-mike.kravetz@oracle.com> In-Reply-To: <20180409230505.18953-1-mike.kravetz@oracle.com> References: <20180409230505.18953-1-mike.kravetz@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Matthew Wilcox , Hugh Dickins , Andrea Arcangeli , Michal Hocko , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , David Herrmann , Khalid Aziz , Andrew Morton , Mike Kravetz In preparation for memfd code restucture, clean up sparse warnings. Most changes required adding __rcu annotations. The routine find_swap_entry was modified to properly deference radix tree entries. Signed-off-by: Mike Kravetz Signed-off-by: Matthew Wilcox --- mm/shmem.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index b85919243399..c7bad16fe884 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -327,7 +327,7 @@ static int shmem_radix_tree_replace(struct address_space *mapping, pgoff_t index, void *expected, void *replacement) { struct radix_tree_node *node; - void **pslot; + void __rcu **pslot; void *item; VM_BUG_ON(!expected); @@ -395,7 +395,7 @@ static bool shmem_confirm_swap(struct address_space *mapping, #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE /* ifdef here to avoid bloating shmem.o when not necessary */ -int shmem_huge __read_mostly; +static int shmem_huge __read_mostly; #if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS) static int shmem_parse_huge(const char *str) @@ -682,7 +682,7 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping, pgoff_t start, pgoff_t end) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; struct page *page; unsigned long swapped = 0; @@ -1098,13 +1098,19 @@ static void shmem_evict_inode(struct inode *inode) static unsigned long find_swap_entry(struct radix_tree_root *root, void *item) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; unsigned long found = -1; unsigned int checked = 0; rcu_read_lock(); radix_tree_for_each_slot(slot, root, &iter, 0) { - if (*slot == item) { + void *entry = radix_tree_deref_slot(slot); + + if (radix_tree_deref_retry(entry)) { + slot = radix_tree_iter_retry(&iter); + continue; + } + if (entry == item) { found = iter.index; break; } @@ -2623,7 +2629,7 @@ static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence) static void shmem_tag_pins(struct address_space *mapping) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; pgoff_t start; struct page *page; @@ -2665,7 +2671,7 @@ static void shmem_tag_pins(struct address_space *mapping) static int shmem_wait_for_pins(struct address_space *mapping) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; pgoff_t start; struct page *page; int error, scan; -- 2.13.6