Changes since v1: - applied the refactoring suggested by Damien
Kanchan Joshi (1): null_blk: synchronization fix for zoned device
drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
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.
Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND") Signed-off-by: Kanchan Joshi joshi.k@samsung.com --- 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; }
On 2020/09/28 18:59, Kanchan Joshi wrote:
Changes since v1:
- applied the refactoring suggested by Damien
Kanchan Joshi (1): null_blk: synchronization fix for zoned device
drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
For single patches, you should add this after the "---" in the patch file, above the patch stats. This is ignores by git when the patch is applied (the patch starts at the first "diff" entry).
On 2020/09/28 18:59, Kanchan Joshi wrote:
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.
Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND") Signed-off-by: Kanchan Joshi joshi.k@samsung.com
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);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;
return null_zone_write(cmd, sector, nr_sectors, true);
sts = null_zone_write(cmd, sector, nr_sectors, true);break;
return null_zone_mgmt(cmd, op, sector);
sts = null_zone_mgmt(cmd, op, sector);break;
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;
}
Looks good.
Reviewed-by: Damien Le Moal damien.lemoal@wdc.com
On Mon, Sep 28, 2020 at 03:25:48PM +0530, Kanchan Joshi wrote:
Changes since v1:
- applied the refactoring suggested by Damien
Kanchan Joshi (1): null_blk: synchronization fix for zoned device
drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
-- 2.25.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
On Mon, Sep 28, 2020 at 5:42 PM Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Sep 28, 2020 at 03:25:48PM +0530, Kanchan Joshi wrote:
Changes since v1:
- applied the refactoring suggested by Damien
Kanchan Joshi (1): null_blk: synchronization fix for zoned device
drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
-- 2.25.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
I'm sorry for the goof-up, Greg.
-- Joshi
On 2020/09/28 19:12, Damien Le Moal wrote:
On 2020/09/28 18:59, Kanchan Joshi wrote:
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.
Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND") Signed-off-by: Kanchan Joshi joshi.k@samsung.com
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);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;
return null_zone_write(cmd, sector, nr_sectors, true);
sts = null_zone_write(cmd, sector, nr_sectors, true);break;
return null_zone_mgmt(cmd, op, sector);
sts = null_zone_mgmt(cmd, op, sector);break;
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;
}
Looks good.
Reviewed-by: Damien Le Moal damien.lemoal@wdc.com
Jens,
Could you queue this patch for rc2 please ? We are seeing some issues with zone append in btrfs testing without it.
On 9/28/20 3:55 AM, Kanchan Joshi wrote:
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.
Applied, thanks.
linux-stable-mirror@lists.linaro.org
-
Damien Le Moal -
Greg KH -
Jens Axboe -
Kanchan Joshi -
Kanchan Joshi