[PATCH] sd: Write lock zone for REQ_OP_WRITE_ZEROES

[damien . lemoal]

From: Damien Le Moal <damien.lem...@wdc.com>

For a zoned block device, sd_zbc_complete() handles zone write unlock on
completion of a REQ_OP_WRITE_ZEROES command but the zone write locking is
missing from sd_setup_write_zeroes_cmnd(). This patch fixes this problem by
locking the target zone of a REQ_OP_WRITE_ZEROES request, ignoring the
unmap == true case (as in this case, the write same command will necessarily
be aligned on the entire zone and be equivalent to a discard which does not
write lock zones).

Signed-off-by: Damien Le Moal <damien.lem...@wdc.com>
---
 drivers/scsi/sd.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index e60a309..b0a525d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -827,6 +827,7 @@ static int sd_setup_write_zeroes_cmnd(struct scsi_cmnd *cmd)
        struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
        u64 sector = blk_rq_pos(rq) >> (ilog2(sdp->sector_size) - 9);
        u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
+       int ret;
 
        if (!(rq->cmd_flags & REQ_NOUNMAP)) {
                switch (sdkp->zeroing_mode) {
@@ -839,9 +840,22 @@ static int sd_setup_write_zeroes_cmnd(struct scsi_cmnd 
*cmd)
 
        if (sdp->no_write_same)
                return BLKPREP_INVALID;
+
+       if (sd_is_zoned(sdkp)) {
+               ret = sd_zbc_write_lock_zone(cmd);
+               if (ret != BLKPREP_OK)
+                       return ret;
+       }
+
        if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff)
-               return sd_setup_write_same16_cmnd(cmd, false);
-       return sd_setup_write_same10_cmnd(cmd, false);
+               ret = sd_setup_write_same16_cmnd(cmd, false);
+       else
+               ret = sd_setup_write_same10_cmnd(cmd, false);
+
+       if (sd_is_zoned(sdkp) && ret != BLKPREP_OK)
+               sd_zbc_write_unlock_zone(cmd);
+
+       return ret;
 }
 
 static void sd_config_write_same(struct scsi_disk *sdkp)
-- 
2.9.3