From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033424AbdEWUfS (ORCPT ); Tue, 23 May 2017 16:35:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49866 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033344AbdEWUfK (ORCPT ); Tue, 23 May 2017 16:35:10 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Mike Snitzer Subject: [PATCH 4.4 015/103] dm bufio: make the parameter "retain_bytes" unsigned long Date: Tue, 23 May 2017 22:08:41 +0200 Message-Id: <20170523200858.673632398@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200856.903752266@linuxfoundation.org> References: <20170523200856.903752266@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 13840d38016203f0095cd547b90352812d24b787 upstream. Change the type of the parameter "retain_bytes" from unsigned to unsigned long, so that on 64-bit machines the user can set more than 4GiB of data to be retained. Also, change the type of the variable "count" in the function "__evict_old_buffers" to unsigned long. The assignment "count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];" could result in unsigned long to unsigned overflow and that could result in buffers not being freed when they should. While at it, avoid division in get_retain_buffers(). Division is slow, we can change it to shift because we have precalculated the log2 of block size. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-bufio.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -222,7 +222,7 @@ static DEFINE_SPINLOCK(param_spinlock); * Buffers are freed after this timeout */ static unsigned dm_bufio_max_age = DM_BUFIO_DEFAULT_AGE_SECS; -static unsigned dm_bufio_retain_bytes = DM_BUFIO_DEFAULT_RETAIN_BYTES; +static unsigned long dm_bufio_retain_bytes = DM_BUFIO_DEFAULT_RETAIN_BYTES; static unsigned long dm_bufio_peak_allocated; static unsigned long dm_bufio_allocated_kmem_cache; @@ -1514,10 +1514,10 @@ static bool __try_evict_buffer(struct dm return true; } -static unsigned get_retain_buffers(struct dm_bufio_client *c) +static unsigned long get_retain_buffers(struct dm_bufio_client *c) { - unsigned retain_bytes = ACCESS_ONCE(dm_bufio_retain_bytes); - return retain_bytes / c->block_size; + unsigned long retain_bytes = ACCESS_ONCE(dm_bufio_retain_bytes); + return retain_bytes >> (c->sectors_per_block_bits + SECTOR_SHIFT); } static unsigned long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan, @@ -1527,7 +1527,7 @@ static unsigned long __scan(struct dm_bu struct dm_buffer *b, *tmp; unsigned long freed = 0; unsigned long count = nr_to_scan; - unsigned retain_target = get_retain_buffers(c); + unsigned long retain_target = get_retain_buffers(c); for (l = 0; l < LIST_SIZE; l++) { list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) { @@ -1753,8 +1753,8 @@ static bool older_than(struct dm_buffer static void __evict_old_buffers(struct dm_bufio_client *c, unsigned long age_hz) { struct dm_buffer *b, *tmp; - unsigned retain_target = get_retain_buffers(c); - unsigned count; + unsigned long retain_target = get_retain_buffers(c); + unsigned long count; LIST_HEAD(write_list); dm_bufio_lock(c); @@ -1915,7 +1915,7 @@ MODULE_PARM_DESC(max_cache_size_bytes, " module_param_named(max_age_seconds, dm_bufio_max_age, uint, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(max_age_seconds, "Max age of a buffer in seconds"); -module_param_named(retain_bytes, dm_bufio_retain_bytes, uint, S_IRUGO | S_IWUSR); +module_param_named(retain_bytes, dm_bufio_retain_bytes, ulong, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(retain_bytes, "Try to keep at least this many bytes cached in memory"); module_param_named(peak_allocated_bytes, dm_bufio_peak_allocated, ulong, S_IRUGO | S_IWUSR);