From 3b481d91356e5693d8358d4ef9c383bdb92c8da0 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Thu, 24 Sep 2020 13:53:28 -0700 Subject: [PATCH] block: add zone specific block statuses A zoned device with limited resources to open or activate zones may return an error when the host exceeds those limits. The same command may be successful if retried later, but the host needs to wait for specific zone states before it should expect a retry to succeed. Have the block layer provide an appropriate status for these conditions so applications can distinuguish this error for special handling. Cc: linux-api@vger.kernel.org Cc: Niklas Cassel Reviewed-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Martin K. Petersen Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- Documentation/block/queue-sysfs.rst | 8 ++++++++ block/blk-core.c | 4 ++++ include/linux/blk_types.h | 18 ++++++++++++++++++ 3 files changed, 30 insertions(+) diff --git a/Documentation/block/queue-sysfs.rst b/Documentation/block/queue-sysfs.rst index f261a5c84170..2638d3446b79 100644 --- a/Documentation/block/queue-sysfs.rst +++ b/Documentation/block/queue-sysfs.rst @@ -124,6 +124,10 @@ For zoned block devices (zoned attribute indicating "host-managed" or EXPLICIT OPEN, IMPLICIT OPEN or CLOSED, is limited by this value. If this value is 0, there is no limit. +If the host attempts to exceed this limit, the driver should report this error +with BLK_STS_ZONE_ACTIVE_RESOURCE, which user space may see as the EOVERFLOW +errno. + max_open_zones (RO) ------------------- For zoned block devices (zoned attribute indicating "host-managed" or @@ -131,6 +135,10 @@ For zoned block devices (zoned attribute indicating "host-managed" or EXPLICIT OPEN or IMPLICIT OPEN, is limited by this value. If this value is 0, there is no limit. +If the host attempts to exceed this limit, the driver should report this error +with BLK_STS_ZONE_OPEN_RESOURCE, which user space may see as the ETOOMANYREFS +errno. + max_sectors_kb (RW) ------------------- This is the maximum number of kilobytes that the block layer will allow diff --git a/block/blk-core.c b/block/blk-core.c index ac00d2fa4eb4..2db8bda43b6e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -186,6 +186,10 @@ static const struct { /* device mapper special case, should not leak out: */ [BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" }, + /* zone device specific errors */ + [BLK_STS_ZONE_OPEN_RESOURCE] = { -ETOOMANYREFS, "open zones exceeded" }, + [BLK_STS_ZONE_ACTIVE_RESOURCE] = { -EOVERFLOW, "active zones exceeded" }, + /* everything else not covered above: */ [BLK_STS_IOERR] = { -EIO, "I/O" }, }; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 7d7c13238fdb..d9b69bbde5cc 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -104,6 +104,24 @@ typedef u8 __bitwise blk_status_t; */ #define BLK_STS_ZONE_RESOURCE ((__force blk_status_t)14) +/* + * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion + * path if the device returns a status indicating that too many zone resources + * are currently open. The same command should be successful if resubmitted + * after the number of open zones decreases below the device's limits, which is + * reported in the request_queue's max_open_zones. + */ +#define BLK_STS_ZONE_OPEN_RESOURCE ((__force blk_status_t)15) + +/* + * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion + * path if the device returns a status indicating that too many zone resources + * are currently active. The same command should be successful if resubmitted + * after the number of active zones decreases below the device's limits, which + * is reported in the request_queue's max_active_zones. + */ +#define BLK_STS_ZONE_ACTIVE_RESOURCE ((__force blk_status_t)16) + /** * blk_path_error - returns true if error may be path related * @error: status the request was completed with