From: Greg KH <gregkh@linuxfoundation.org>
To: Shuah Khan <skhan@linuxfoundation.org>
Cc: david.kershner@unisys.com, keescook@chromium.org,
peterz@infradead.org, devel@driverdev.osuosl.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 12/13] drivers/staging/unisys/visorhba: convert stats to use seqnum_ops
Date: Tue, 10 Nov 2020 21:42:21 +0100 [thread overview]
Message-ID: <X6r7LVcXBBvRIbd8@kroah.com> (raw)
In-Reply-To: <6fb679d23de785bbd1be6a528127e29f8ee6abd7.1605027593.git.skhan@linuxfoundation.org>
On Tue, Nov 10, 2020 at 12:53:38PM -0700, Shuah Khan wrote:
> seqnum_ops api is introduced to be used when a variable is used as
> a sequence/stat counter and doesn't guard object lifetimes. This
> clearly differentiates atomic_t usages that guard object lifetimes.
>
> seqnum32 variables wrap around to INT_MIN when it overflows and
> should not be used to guard resource lifetimes, device usage and
> open counts that control state changes, and pm states.
>
> atomic_t variables used for error_count and ios_threshold are atomic
> counters and guarded by max. values. No change to the behavior with
> this change.
>
> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> ---
> .../staging/unisys/visorhba/visorhba_main.c | 37 ++++++++++---------
> 1 file changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/staging/unisys/visorhba/visorhba_main.c b/drivers/staging/unisys/visorhba/visorhba_main.c
> index 7ae5306b92fe..3209958b8aaa 100644
> --- a/drivers/staging/unisys/visorhba/visorhba_main.c
> +++ b/drivers/staging/unisys/visorhba/visorhba_main.c
> @@ -10,6 +10,7 @@
> #include <linux/module.h>
> #include <linux/seq_file.h>
> #include <linux/visorbus.h>
> +#include <linux/seqnum_ops.h>
> #include <scsi/scsi.h>
> #include <scsi/scsi_host.h>
> #include <scsi/scsi_cmnd.h>
> @@ -41,8 +42,8 @@ MODULE_ALIAS("visorbus:" VISOR_VHBA_CHANNEL_GUID_STR);
> struct visordisk_info {
> struct scsi_device *sdev;
> u32 valid;
> - atomic_t ios_threshold;
> - atomic_t error_count;
> + struct seqnum32 ios_threshold;
> + struct seqnum32 error_count;
Are you sure the threshold variable is a sequence number?
It goes up and down, not just up and up and up.
An error count just goes up :)
thanks,
greg k-h
next prev parent reply other threads:[~2020-11-10 20:41 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 19:53 [PATCH 00/13] Introduce seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 01/13] seqnum_ops: Introduce Sequence Number Ops Shuah Khan
2020-11-10 20:41 ` Greg KH
2020-11-10 20:43 ` Greg KH
2020-11-11 0:18 ` Kees Cook
2020-11-11 19:23 ` Shuah Khan
2020-11-12 12:36 ` Matthew Wilcox
2020-11-12 16:17 ` Shuah Khan
2020-11-12 16:45 ` Greg KH
2020-11-12 16:59 ` Shuah Khan
2020-11-12 21:27 ` Shuah Khan
2020-11-17 12:27 ` Peter Zijlstra
2020-11-10 21:03 ` Matthew Wilcox
2020-11-10 22:58 ` Shuah Khan
2020-11-11 0:20 ` Kees Cook
2020-11-11 15:42 ` Shuah Khan
2020-11-11 8:23 ` Peter Zijlstra
2020-11-11 15:56 ` Shuah Khan
2020-11-11 16:04 ` Peter Zijlstra
2020-11-11 17:34 ` Shuah Khan
2020-11-11 17:50 ` Peter Zijlstra
2020-11-11 18:28 ` Shuah Khan
2020-11-11 20:15 ` Peter Zijlstra
2020-11-12 13:29 ` Greg KH
2020-11-10 19:53 ` [PATCH 02/13] selftests:lib:test_seqnum_ops: add new test for seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 03/13] drivers/acpi: convert seqno seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 04/13] drivers/acpi/apei: convert seqno to seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 05/13] drivers/base/test/test_async_driver_probe: convert to use seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 06/13] drivers/char/ipmi: convert stats " Shuah Khan
2020-11-10 19:53 ` [PATCH 07/13] drivers/edac: convert pci counters to seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 08/13] drivers/oprofile: convert stats to use seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 09/13] drivers/staging/rtl8723bs: " Shuah Khan
2020-11-10 19:53 ` [PATCH 10/13] usb: usbip/vhci: convert seqno to seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 11/13] drivers/staging/rtl8188eu: convert stats to use seqnum_ops Shuah Khan
2020-11-10 19:53 ` [PATCH 12/13] drivers/staging/unisys/visorhba: " Shuah Khan
2020-11-10 20:42 ` Greg KH [this message]
2020-11-10 21:02 ` Shuah Khan
2020-11-10 19:53 ` [PATCH 13/13] security/integrity/ima: converts stats to seqnum_ops Shuah Khan
2020-11-10 20:44 ` [PATCH 00/13] Introduce seqnum_ops Alan Stern
2020-11-10 22:42 ` Shuah Khan
2020-11-11 4:33 ` Matthew Wilcox
2020-11-11 16:03 ` Shuah Khan
2020-11-11 16:41 ` Matthew Wilcox
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