FAILED: patch "[PATCH] null_blk: Fix zone reset all tracing" failed to apply to 5.9-stable tree

FAILED: patch "[PATCH] null_blk: Fix zone reset all tracing" failed to apply to 5.9-stable tree

[gregkh]

The patch below does not apply to the 5.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f9c9104288da543cd64f186f9e2fba389f415630 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <damien.lemoal@wdc.com>
Date: Thu, 29 Oct 2020 20:04:59 +0900
Subject: [PATCH] null_blk: Fix zone reset all tracing

In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
ignored and the operation is applied to all sequential zones. For these
commands, tracing the effect of the command using the command sector to
determine the target zone is thus incorrect.

Fix null_zone_mgmt() zone condition tracing in the case of
REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
not already empty.

Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 98056c88926b..b637b16a5f54 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -475,9 +475,14 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 
 	switch (op) {
 	case REQ_OP_ZONE_RESET_ALL:
-		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++)
-			null_reset_zone(dev, &dev->zones[i]);
-		break;
+		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
+			zone = &dev->zones[i];
+			if (zone->cond != BLK_ZONE_COND_EMPTY) {
+				null_reset_zone(dev, zone);
+				trace_nullb_zone_op(cmd, i, zone->cond);
+			}
+		}
+		return BLK_STS_OK;
 	case REQ_OP_ZONE_RESET:
 		ret = null_reset_zone(dev, zone);
 		break;

Re: FAILED: patch "[PATCH] null_blk: Fix zone reset all tracing" failed to apply to 5.9-stable tree

[Damien Le Moal]

On 2020/11/03 23:23, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.9-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

I will send a backported patch shortly. Thanks.

> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> From f9c9104288da543cd64f186f9e2fba389f415630 Mon Sep 17 00:00:00 2001
> From: Damien Le Moal <damien.lemoal@wdc.com>
> Date: Thu, 29 Oct 2020 20:04:59 +0900
> Subject: [PATCH] null_blk: Fix zone reset all tracing
> 
> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
> ignored and the operation is applied to all sequential zones. For these
> commands, tracing the effect of the command using the command sector to
> determine the target zone is thus incorrect.
> 
> Fix null_zone_mgmt() zone condition tracing in the case of
> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
> not already empty.
> 
> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> 
> diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
> index 98056c88926b..b637b16a5f54 100644
> --- a/drivers/block/null_blk_zoned.c
> +++ b/drivers/block/null_blk_zoned.c
> @@ -475,9 +475,14 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
>  
>  	switch (op) {
>  	case REQ_OP_ZONE_RESET_ALL:
> -		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++)
> -			null_reset_zone(dev, &dev->zones[i]);
> -		break;
> +		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
> +			zone = &dev->zones[i];
> +			if (zone->cond != BLK_ZONE_COND_EMPTY) {
> +				null_reset_zone(dev, zone);
> +				trace_nullb_zone_op(cmd, i, zone->cond);
> +			}
> +		}
> +		return BLK_STS_OK;
>  	case REQ_OP_ZONE_RESET:
>  		ret = null_reset_zone(dev, zone);
>  		break;
> 
> 


-- 
Damien Le Moal
Western Digital Research

[PATCH] null_blk: Fix zone reset all tracing

[Damien Le Moal]

commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.

In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
ignored and the operation is applied to all sequential zones. For these
commands, tracing the effect of the command using the command sector to
determine the target zone is thus incorrect.

Fix null_zone_mgmt() zone condition tracing in the case of
REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
not already empty.

Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/block/null_blk_zoned.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 3d25c9ad2383..fcbbe2e4ef2d 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -226,13 +226,15 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 
 	switch (op) {
 	case REQ_OP_ZONE_RESET_ALL:
-		for (i = 0; i < dev->nr_zones; i++) {
-			if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
-				continue;
-			zone[i].cond = BLK_ZONE_COND_EMPTY;
-			zone[i].wp = zone[i].start;
+		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
+			zone = &dev->zones[i];
+			if (zone->cond != BLK_ZONE_COND_EMPTY) {
+				zone->cond = BLK_ZONE_COND_EMPTY;
+				zone->wp = zone->start;
+				trace_nullb_zone_op(cmd, i, zone->cond);
+			}
 		}
-		break;
+		return BLK_STS_OK;
 	case REQ_OP_ZONE_RESET:
 		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 			return BLK_STS_IOERR;
-- 
2.26.2

Re: [PATCH] null_blk: Fix zone reset all tracing

[Greg Kroah-Hartman]

On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
> commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
> 
> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
> ignored and the operation is applied to all sequential zones. For these
> commands, tracing the effect of the command using the command sector to
> determine the target zone is thus incorrect.
> 
> Fix null_zone_mgmt() zone condition tracing in the case of
> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
> not already empty.
> 
> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> ---
>  drivers/block/null_blk_zoned.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)

Now queued up, thanks.

greg k-h

Re: [PATCH] null_blk: Fix zone reset all tracing

[Greg Kroah-Hartman]

On Wed, Nov 04, 2020 at 10:10:15AM +0100, Greg Kroah-Hartman wrote:
> On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
> > commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
> > 
> > In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
> > ignored and the operation is applied to all sequential zones. For these
> > commands, tracing the effect of the command using the command sector to
> > determine the target zone is thus incorrect.
> > 
> > Fix null_zone_mgmt() zone condition tracing in the case of
> > REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
> > not already empty.
> > 
> > Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
> > Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > ---
> >  drivers/block/null_blk_zoned.c | 14 ++++++++------
> >  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> Now queued up, thanks.

Wait, no, I'll delay this one until the next round as it's not fixing
something introduced in this -rc series.

thanks,

greg k-h

Re: [PATCH] null_blk: Fix zone reset all tracing

[Damien Le Moal]

On 2020/11/04 18:14, Greg Kroah-Hartman wrote:
> On Wed, Nov 04, 2020 at 10:10:15AM +0100, Greg Kroah-Hartman wrote:
>> On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
>>> commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
>>>
>>> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
>>> ignored and the operation is applied to all sequential zones. For these
>>> commands, tracing the effect of the command using the command sector to
>>> determine the target zone is thus incorrect.
>>>
>>> Fix null_zone_mgmt() zone condition tracing in the case of
>>> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
>>> not already empty.
>>>
>>> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>>> ---
>>>  drivers/block/null_blk_zoned.c | 14 ++++++++------
>>>  1 file changed, 8 insertions(+), 6 deletions(-)
>>
>> Now queued up, thanks.
> 
> Wait, no, I'll delay this one until the next round as it's not fixing
> something introduced in this -rc series.

Yes, that problem is older.
The lock fix I sent goes on top of this one though. I can send the backport for
the lock fix without this patch applied. Is that OK ?

> 
> thanks,
> 
> greg k-h
> 


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] null_blk: Fix zone reset all tracing

[Greg Kroah-Hartman]

On Wed, Nov 04, 2020 at 09:21:27AM +0000, Damien Le Moal wrote:
> On 2020/11/04 18:14, Greg Kroah-Hartman wrote:
> > On Wed, Nov 04, 2020 at 10:10:15AM +0100, Greg Kroah-Hartman wrote:
> >> On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
> >>> commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
> >>>
> >>> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
> >>> ignored and the operation is applied to all sequential zones. For these
> >>> commands, tracing the effect of the command using the command sector to
> >>> determine the target zone is thus incorrect.
> >>>
> >>> Fix null_zone_mgmt() zone condition tracing in the case of
> >>> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
> >>> not already empty.
> >>>
> >>> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
> >>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> >>> Cc: stable@vger.kernel.org
> >>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> >>> ---
> >>>  drivers/block/null_blk_zoned.c | 14 ++++++++------
> >>>  1 file changed, 8 insertions(+), 6 deletions(-)
> >>
> >> Now queued up, thanks.
> > 
> > Wait, no, I'll delay this one until the next round as it's not fixing
> > something introduced in this -rc series.
> 
> Yes, that problem is older.
> The lock fix I sent goes on top of this one though. I can send the backport for
> the lock fix without this patch applied. Is that OK ?

If the order of the patches is needed, then yes, I can take both, please
submit them as a patch series so that I know this is needed.

thanks,

greg k-h

Re: [PATCH] null_blk: Fix zone reset all tracing

[Damien Le Moal]

On 2020/11/04 18:26, Greg Kroah-Hartman wrote:
> On Wed, Nov 04, 2020 at 09:21:27AM +0000, Damien Le Moal wrote:
>> On 2020/11/04 18:14, Greg Kroah-Hartman wrote:
>>> On Wed, Nov 04, 2020 at 10:10:15AM +0100, Greg Kroah-Hartman wrote:
>>>> On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
>>>>> commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
>>>>>
>>>>> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
>>>>> ignored and the operation is applied to all sequential zones. For these
>>>>> commands, tracing the effect of the command using the command sector to
>>>>> determine the target zone is thus incorrect.
>>>>>
>>>>> Fix null_zone_mgmt() zone condition tracing in the case of
>>>>> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
>>>>> not already empty.
>>>>>
>>>>> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
>>>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>>>>> Cc: stable@vger.kernel.org
>>>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>>>>> ---
>>>>>  drivers/block/null_blk_zoned.c | 14 ++++++++------
>>>>>  1 file changed, 8 insertions(+), 6 deletions(-)
>>>>
>>>> Now queued up, thanks.
>>>
>>> Wait, no, I'll delay this one until the next round as it's not fixing
>>> something introduced in this -rc series.
>>
>> Yes, that problem is older.
>> The lock fix I sent goes on top of this one though. I can send the backport for
>> the lock fix without this patch applied. Is that OK ?
> 
> If the order of the patches is needed, then yes, I can take both, please
> submit them as a patch series so that I know this is needed.

OK. Sending that. Note that I still do not see Kanchan patch applied in stable
5.9.y branch, so I will do the backport assuming it is applied. Or I can send
all 3 patches as the series. Which do you prefer ?

> 
> thanks,
> 
> greg k-h
> 


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] null_blk: Fix zone reset all tracing

[Greg Kroah-Hartman]

On Wed, Nov 04, 2020 at 09:31:40AM +0000, Damien Le Moal wrote:
> On 2020/11/04 18:26, Greg Kroah-Hartman wrote:
> > On Wed, Nov 04, 2020 at 09:21:27AM +0000, Damien Le Moal wrote:
> >> On 2020/11/04 18:14, Greg Kroah-Hartman wrote:
> >>> On Wed, Nov 04, 2020 at 10:10:15AM +0100, Greg Kroah-Hartman wrote:
> >>>> On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
> >>>>> commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
> >>>>>
> >>>>> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
> >>>>> ignored and the operation is applied to all sequential zones. For these
> >>>>> commands, tracing the effect of the command using the command sector to
> >>>>> determine the target zone is thus incorrect.
> >>>>>
> >>>>> Fix null_zone_mgmt() zone condition tracing in the case of
> >>>>> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
> >>>>> not already empty.
> >>>>>
> >>>>> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
> >>>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> >>>>> Cc: stable@vger.kernel.org
> >>>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> >>>>> ---
> >>>>>  drivers/block/null_blk_zoned.c | 14 ++++++++------
> >>>>>  1 file changed, 8 insertions(+), 6 deletions(-)
> >>>>
> >>>> Now queued up, thanks.
> >>>
> >>> Wait, no, I'll delay this one until the next round as it's not fixing
> >>> something introduced in this -rc series.
> >>
> >> Yes, that problem is older.
> >> The lock fix I sent goes on top of this one though. I can send the backport for
> >> the lock fix without this patch applied. Is that OK ?
> > 
> > If the order of the patches is needed, then yes, I can take both, please
> > submit them as a patch series so that I know this is needed.
> 
> OK. Sending that. Note that I still do not see Kanchan patch applied in stable
> 5.9.y branch, so I will do the backport assuming it is applied. Or I can send
> all 3 patches as the series. Which do you prefer ?

All 3 is great, to ensure I have them all as I don't know what you mean
by "Kanchan patch".

thanks,

greg k-h

Re: [PATCH] null_blk: Fix zone reset all tracing

[Damien Le Moal]

On 2020/11/04 18:50, Greg Kroah-Hartman wrote:
> On Wed, Nov 04, 2020 at 09:31:40AM +0000, Damien Le Moal wrote:
>> On 2020/11/04 18:26, Greg Kroah-Hartman wrote:
>>> On Wed, Nov 04, 2020 at 09:21:27AM +0000, Damien Le Moal wrote:
>>>> On 2020/11/04 18:14, Greg Kroah-Hartman wrote:
>>>>> On Wed, Nov 04, 2020 at 10:10:15AM +0100, Greg Kroah-Hartman wrote:
>>>>>> On Wed, Nov 04, 2020 at 02:29:14PM +0900, Damien Le Moal wrote:
>>>>>>> commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.
>>>>>>>
>>>>>>> In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
>>>>>>> ignored and the operation is applied to all sequential zones. For these
>>>>>>> commands, tracing the effect of the command using the command sector to
>>>>>>> determine the target zone is thus incorrect.
>>>>>>>
>>>>>>> Fix null_zone_mgmt() zone condition tracing in the case of
>>>>>>> REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
>>>>>>> not already empty.
>>>>>>>
>>>>>>> Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
>>>>>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>>>>>>> Cc: stable@vger.kernel.org
>>>>>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>>>>>>> ---
>>>>>>>  drivers/block/null_blk_zoned.c | 14 ++++++++------
>>>>>>>  1 file changed, 8 insertions(+), 6 deletions(-)
>>>>>>
>>>>>> Now queued up, thanks.
>>>>>
>>>>> Wait, no, I'll delay this one until the next round as it's not fixing
>>>>> something introduced in this -rc series.
>>>>
>>>> Yes, that problem is older.
>>>> The lock fix I sent goes on top of this one though. I can send the backport for
>>>> the lock fix without this patch applied. Is that OK ?
>>>
>>> If the order of the patches is needed, then yes, I can take both, please
>>> submit them as a patch series so that I know this is needed.
>>
>> OK. Sending that. Note that I still do not see Kanchan patch applied in stable
>> 5.9.y branch, so I will do the backport assuming it is applied. Or I can send
>> all 3 patches as the series. Which do you prefer ?
> 
> All 3 is great, to ensure I have them all as I don't know what you mean
> by "Kanchan patch".

I was talking about "
commit 35bc10b2eafbb701064b94f283b77c54d3304842 upstream." that you already
applied to 5.9.y.

Sending all 3 patches backported in a series to be sure. SInce the first patchin
the series will be the above mentioned patch, everything should still apply
cleanly on your side. Thanks!

> 
> thanks,
> 
> greg k-h
> 


-- 
Damien Le Moal
Western Digital Research

[PATCH 0/3] null_blk fixes for 5.9 stable

[Damien Le Moal]

Greg,

Here are three backported patches from this cycle for 5.9 stable. The
upstream patches are:
1) 35bc10b2eafbb701064b94f283b77c54d3304842
2) f9c9104288da543cd64f186f9e2fba389f415630
3) aa1c09cb65e2ed17cb8e652bc7ec84e0af1229eb

Thanks.

Damien Le Moal (2):
  null_blk: Fix zone reset all tracing
  null_blk: Fix locking in zoned mode

Kanchan Joshi (1):
  null_blk: synchronization fix for zoned device

 drivers/block/null_blk.h       |   1 +
 drivers/block/null_blk_zoned.c | 157 ++++++++++++++++++++++++---------
 2 files changed, 118 insertions(+), 40 deletions(-)

-- 
2.26.2

[PATCH 1/3] null_blk: synchronization fix for zoned device

[Damien Le Moal]

From: Kanchan Joshi <joshi.k@samsung.com>

commit 35bc10b2eafbb701064b94f283b77c54d3304842 upstream.

Parallel write,read,zone-mgmt operations accessing/altering zone state
and write-pointer may get into race. Avoid the situation by using a new
spinlock for zoned device.
Concurrent zone-appends (on a zone) returning same write-pointer issue
is also avoided using this lock.

Cc: stable@vger.kernel.org
Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND")
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/block/null_blk.h       |  1 +
 drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h
index daed4a9c3436..28099be50395 100644
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -44,6 +44,7 @@ struct nullb_device {
 	unsigned int nr_zones;
 	struct blk_zone *zones;
 	sector_t zone_size_sects;
+	spinlock_t zone_lock;
 
 	unsigned long size; /* device size in MB */
 	unsigned long completion_nsec; /* time in ns to complete a request */
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 3d25c9ad2383..e8d8b13aaa5a 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -45,6 +45,7 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
 	if (!dev->zones)
 		return -ENOMEM;
 
+	spin_lock_init(&dev->zone_lock);
 	if (dev->zone_nr_conv >= dev->nr_zones) {
 		dev->zone_nr_conv = dev->nr_zones - 1;
 		pr_info("changed the number of conventional zones to %u",
@@ -131,8 +132,11 @@ int null_report_zones(struct gendisk *disk, sector_t sector,
 		 * So use a local copy to avoid corruption of the device zone
 		 * array.
 		 */
+		spin_lock_irq(&dev->zone_lock);
 		memcpy(&zone, &dev->zones[first_zone + i],
 		       sizeof(struct blk_zone));
+		spin_unlock_irq(&dev->zone_lock);
+
 		error = cb(&zone, i, data);
 		if (error)
 			return error;
@@ -277,18 +281,28 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op,
 				    sector_t sector, sector_t nr_sectors)
 {
+	blk_status_t sts;
+	struct nullb_device *dev = cmd->nq->dev;
+
+	spin_lock_irq(&dev->zone_lock);
 	switch (op) {
 	case REQ_OP_WRITE:
-		return null_zone_write(cmd, sector, nr_sectors, false);
+		sts = null_zone_write(cmd, sector, nr_sectors, false);
+		break;
 	case REQ_OP_ZONE_APPEND:
-		return null_zone_write(cmd, sector, nr_sectors, true);
+		sts = null_zone_write(cmd, sector, nr_sectors, true);
+		break;
 	case REQ_OP_ZONE_RESET:
 	case REQ_OP_ZONE_RESET_ALL:
 	case REQ_OP_ZONE_OPEN:
 	case REQ_OP_ZONE_CLOSE:
 	case REQ_OP_ZONE_FINISH:
-		return null_zone_mgmt(cmd, op, sector);
+		sts = null_zone_mgmt(cmd, op, sector);
+		break;
 	default:
-		return null_process_cmd(cmd, op, sector, nr_sectors);
+		sts = null_process_cmd(cmd, op, sector, nr_sectors);
 	}
+	spin_unlock_irq(&dev->zone_lock);
+
+	return sts;
 }
-- 
2.26.2

[PATCH 2/3] null_blk: Fix zone reset all tracing

[Damien Le Moal]

commit f9c9104288da543cd64f186f9e2fba389f415630 upstream.

In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
ignored and the operation is applied to all sequential zones. For these
commands, tracing the effect of the command using the command sector to
determine the target zone is thus incorrect.

Fix null_zone_mgmt() zone condition tracing in the case of
REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
not already empty.

Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/block/null_blk_zoned.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index e8d8b13aaa5a..0342696db0ce 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -230,13 +230,15 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 
 	switch (op) {
 	case REQ_OP_ZONE_RESET_ALL:
-		for (i = 0; i < dev->nr_zones; i++) {
-			if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
-				continue;
-			zone[i].cond = BLK_ZONE_COND_EMPTY;
-			zone[i].wp = zone[i].start;
+		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
+			zone = &dev->zones[i];
+			if (zone->cond != BLK_ZONE_COND_EMPTY) {
+				zone->cond = BLK_ZONE_COND_EMPTY;
+				zone->wp = zone->start;
+				trace_nullb_zone_op(cmd, i, zone->cond);
+			}
 		}
-		break;
+		return BLK_STS_OK;
 	case REQ_OP_ZONE_RESET:
 		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 			return BLK_STS_IOERR;
-- 
2.26.2

[PATCH 3/3] null_blk: Fix locking in zoned mode

[Damien Le Moal]

commit aa1c09cb65e2ed17cb8e652bc7ec84e0af1229eb upstream.

When the zoned mode is enabled in null_blk, Serializing read, write
and zone management operations for each zone is necessary to protect
device level information for managing zone resources (zone open and
closed counters) as well as each zone condition and write pointer
position. Commit 35bc10b2eafb ("null_blk: synchronization fix for
zoned device") introduced a spinlock to implement this serialization.
However, when memory backing is also enabled, GFP_NOIO memory
allocations are executed under the spinlock, resulting in might_sleep()
warnings. Furthermore, the zone_lock spinlock is locked/unlocked using
spin_lock_irq/spin_unlock_irq, similarly to the memory backing code with
the nullb->lock spinlock. This nested use of irq locks wrecks the irq
enabled/disabled state.

Fix all this by introducing a bitmap for per-zone lock, with locking
implemented using wait_on_bit_lock_io() and clear_and_wake_up_bit().
This locking mechanism allows keeping a zone locked while executing
null_process_cmd(), serializing all operations to the zone while
allowing to sleep during memory backing allocation with GFP_NOIO.
Device level zone resource management information is protected using
a spinlock which is not held while executing null_process_cmd();

Fixes: 35bc10b2eafb ("null_blk: synchronization fix for zoned device")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/block/null_blk.h       |   2 +-
 drivers/block/null_blk_zoned.c | 133 ++++++++++++++++++++++++---------
 2 files changed, 98 insertions(+), 37 deletions(-)

diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h
index 28099be50395..206309ecc7e4 100644
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -44,7 +44,7 @@ struct nullb_device {
 	unsigned int nr_zones;
 	struct blk_zone *zones;
 	sector_t zone_size_sects;
-	spinlock_t zone_lock;
+	unsigned long *zone_locks;
 
 	unsigned long size; /* device size in MB */
 	unsigned long completion_nsec; /* time in ns to complete a request */
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 0342696db0ce..495713d6c989 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/vmalloc.h>
+#include <linux/bitmap.h>
 #include "null_blk.h"
 
 #define CREATE_TRACE_POINTS
@@ -45,7 +46,12 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
 	if (!dev->zones)
 		return -ENOMEM;
 
-	spin_lock_init(&dev->zone_lock);
+	dev->zone_locks = bitmap_zalloc(dev->nr_zones, GFP_KERNEL);
+	if (!dev->zone_locks) {
+		kvfree(dev->zones);
+		return -ENOMEM;
+	}
+
 	if (dev->zone_nr_conv >= dev->nr_zones) {
 		dev->zone_nr_conv = dev->nr_zones - 1;
 		pr_info("changed the number of conventional zones to %u",
@@ -106,15 +112,26 @@ int null_register_zoned_dev(struct nullb *nullb)
 
 void null_free_zoned_dev(struct nullb_device *dev)
 {
+	bitmap_free(dev->zone_locks);
 	kvfree(dev->zones);
 }
 
+static inline void null_lock_zone(struct nullb_device *dev, unsigned int zno)
+{
+	wait_on_bit_lock_io(dev->zone_locks, zno, TASK_UNINTERRUPTIBLE);
+}
+
+static inline void null_unlock_zone(struct nullb_device *dev, unsigned int zno)
+{
+	clear_and_wake_up_bit(zno, dev->zone_locks);
+}
+
 int null_report_zones(struct gendisk *disk, sector_t sector,
 		unsigned int nr_zones, report_zones_cb cb, void *data)
 {
 	struct nullb *nullb = disk->private_data;
 	struct nullb_device *dev = nullb->dev;
-	unsigned int first_zone, i;
+	unsigned int first_zone, i, zno;
 	struct blk_zone zone;
 	int error;
 
@@ -125,17 +142,17 @@ int null_report_zones(struct gendisk *disk, sector_t sector,
 	nr_zones = min(nr_zones, dev->nr_zones - first_zone);
 	trace_nullb_report_zones(nullb, nr_zones);
 
-	for (i = 0; i < nr_zones; i++) {
+	zno = first_zone;
+	for (i = 0; i < nr_zones; i++, zno++) {
 		/*
 		 * Stacked DM target drivers will remap the zone information by
 		 * modifying the zone information passed to the report callback.
 		 * So use a local copy to avoid corruption of the device zone
 		 * array.
 		 */
-		spin_lock_irq(&dev->zone_lock);
-		memcpy(&zone, &dev->zones[first_zone + i],
-		       sizeof(struct blk_zone));
-		spin_unlock_irq(&dev->zone_lock);
+		null_lock_zone(dev, zno);
+		memcpy(&zone, &dev->zones[zno], sizeof(struct blk_zone));
+		null_unlock_zone(dev, zno);
 
 		error = cb(&zone, i, data);
 		if (error)
@@ -145,6 +162,10 @@ int null_report_zones(struct gendisk *disk, sector_t sector,
 	return nr_zones;
 }
 
+/*
+ * This is called in the case of memory backing from null_process_cmd()
+ * with the target zone already locked.
+ */
 size_t null_zone_valid_read_len(struct nullb *nullb,
 				sector_t sector, unsigned int len)
 {
@@ -176,10 +197,13 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 		return null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
 
+	null_lock_zone(dev, zno);
+
 	switch (zone->cond) {
 	case BLK_ZONE_COND_FULL:
 		/* Cannot write to a full zone */
-		return BLK_STS_IOERR;
+		ret = BLK_STS_IOERR;
+		break;
 	case BLK_ZONE_COND_EMPTY:
 	case BLK_ZONE_COND_IMP_OPEN:
 	case BLK_ZONE_COND_EXP_OPEN:
@@ -197,68 +221,96 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 			else
 				cmd->rq->__sector = sector;
 		} else if (sector != zone->wp) {
-			return BLK_STS_IOERR;
+			ret = BLK_STS_IOERR;
+			break;
 		}
 
-		if (zone->wp + nr_sectors > zone->start + zone->capacity)
-			return BLK_STS_IOERR;
+		if (zone->wp + nr_sectors > zone->start + zone->capacity) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
 
 		if (zone->cond != BLK_ZONE_COND_EXP_OPEN)
 			zone->cond = BLK_ZONE_COND_IMP_OPEN;
 
 		ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
 		if (ret != BLK_STS_OK)
-			return ret;
+			break;
 
 		zone->wp += nr_sectors;
 		if (zone->wp == zone->start + zone->capacity)
 			zone->cond = BLK_ZONE_COND_FULL;
-		return BLK_STS_OK;
+		ret = BLK_STS_OK;
+		break;
 	default:
 		/* Invalid zone condition */
-		return BLK_STS_IOERR;
+		ret = BLK_STS_IOERR;
 	}
+
+	null_unlock_zone(dev, zno);
+
+	return ret;
 }
 
 static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 				   sector_t sector)
 {
 	struct nullb_device *dev = cmd->nq->dev;
-	unsigned int zone_no = null_zone_no(dev, sector);
-	struct blk_zone *zone = &dev->zones[zone_no];
+	unsigned int zone_no;
+	struct blk_zone *zone;
+	blk_status_t ret = BLK_STS_OK;
 	size_t i;
 
-	switch (op) {
-	case REQ_OP_ZONE_RESET_ALL:
+	if (op == REQ_OP_ZONE_RESET_ALL) {
 		for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
+			null_lock_zone(dev, i);
 			zone = &dev->zones[i];
 			if (zone->cond != BLK_ZONE_COND_EMPTY) {
 				zone->cond = BLK_ZONE_COND_EMPTY;
 				zone->wp = zone->start;
 				trace_nullb_zone_op(cmd, i, zone->cond);
 			}
+			null_unlock_zone(dev, i);
 		}
 		return BLK_STS_OK;
+	}
+
+	zone_no = null_zone_no(dev, sector);
+	zone = &dev->zones[zone_no];
+
+	null_lock_zone(dev, zone_no);
+
+	switch (op) {
 	case REQ_OP_ZONE_RESET:
-		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
-			return BLK_STS_IOERR;
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
 
 		zone->cond = BLK_ZONE_COND_EMPTY;
 		zone->wp = zone->start;
 		break;
 	case REQ_OP_ZONE_OPEN:
-		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
-			return BLK_STS_IOERR;
-		if (zone->cond == BLK_ZONE_COND_FULL)
-			return BLK_STS_IOERR;
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
+		if (zone->cond == BLK_ZONE_COND_FULL) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
 
 		zone->cond = BLK_ZONE_COND_EXP_OPEN;
 		break;
 	case REQ_OP_ZONE_CLOSE:
-		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
-			return BLK_STS_IOERR;
-		if (zone->cond == BLK_ZONE_COND_FULL)
-			return BLK_STS_IOERR;
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
+		if (zone->cond == BLK_ZONE_COND_FULL) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
 
 		if (zone->wp == zone->start)
 			zone->cond = BLK_ZONE_COND_EMPTY;
@@ -266,27 +318,35 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 			zone->cond = BLK_ZONE_COND_CLOSED;
 		break;
 	case REQ_OP_ZONE_FINISH:
-		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
-			return BLK_STS_IOERR;
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+			ret = BLK_STS_IOERR;
+			break;
+		}
 
 		zone->cond = BLK_ZONE_COND_FULL;
 		zone->wp = zone->start + zone->len;
+		ret = BLK_STS_OK;
 		break;
 	default:
-		return BLK_STS_NOTSUPP;
+		ret = BLK_STS_NOTSUPP;
+		break;
 	}
 
-	trace_nullb_zone_op(cmd, zone_no, zone->cond);
-	return BLK_STS_OK;
+	if (ret == BLK_STS_OK)
+		trace_nullb_zone_op(cmd, zone_no, zone->cond);
+
+	null_unlock_zone(dev, zone_no);
+
+	return ret;
 }
 
 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op,
 				    sector_t sector, sector_t nr_sectors)
 {
-	blk_status_t sts;
 	struct nullb_device *dev = cmd->nq->dev;
+	unsigned int zno = null_zone_no(dev, sector);
+	blk_status_t sts;
 
-	spin_lock_irq(&dev->zone_lock);
 	switch (op) {
 	case REQ_OP_WRITE:
 		sts = null_zone_write(cmd, sector, nr_sectors, false);
@@ -302,9 +362,10 @@ blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op,
 		sts = null_zone_mgmt(cmd, op, sector);
 		break;
 	default:
+		null_lock_zone(dev, zno);
 		sts = null_process_cmd(cmd, op, sector, nr_sectors);
+		null_unlock_zone(dev, zno);
 	}
-	spin_unlock_irq(&dev->zone_lock);
 
 	return sts;
 }
-- 
2.26.2

Re: [PATCH 0/3] null_blk fixes for 5.9 stable

[Greg Kroah-Hartman]

On Wed, Nov 04, 2020 at 08:27:44PM +0900, Damien Le Moal wrote:
> Greg,
> 
> Here are three backported patches from this cycle for 5.9 stable. The
> upstream patches are:
> 1) 35bc10b2eafbb701064b94f283b77c54d3304842
> 2) f9c9104288da543cd64f186f9e2fba389f415630
> 3) aa1c09cb65e2ed17cb8e652bc7ec84e0af1229eb
> 
> Thanks.
> 
> Damien Le Moal (2):
>   null_blk: Fix zone reset all tracing
>   null_blk: Fix locking in zoned mode
> 
> Kanchan Joshi (1):
>   null_blk: synchronization fix for zoned device
> 
>  drivers/block/null_blk.h       |   1 +
>  drivers/block/null_blk_zoned.c | 157 ++++++++++++++++++++++++---------
>  2 files changed, 118 insertions(+), 40 deletions(-)

All now queued up, thanks.

greg k-h