scsi: sd_zbc: Do not write lock zones for reset

Resetting a zone write pointer is equivalent to discarding sectors:
after a reset, the zone sectors will contain zeros (or the format
pattern). So there is no need for mutual exclusion between a zone reset
and write. Similarly to discard, make it the responsability of the user
to properly synchronize between reset and write (as is done now for
discard and write).

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 29ba1d7e9b2e8814186dc1ff35cf17ba54dd42d4..fcf0fad72dd9b89069e3f34f2f35b04989d5e070 100644 (file)
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -237,7 +237,6 @@ int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
        struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
        sector_t sector = blk_rq_pos(rq);
        sector_t block = sectors_to_logical(sdkp->device, sector);
-       unsigned int zno = block >> sdkp->zone_shift;
 
        if (!sd_is_zoned(sdkp))
                /* Not a zoned device */
@@ -250,11 +249,6 @@ int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
                /* Unaligned request */
                return BLKPREP_KILL;
 
-       /* Do not allow concurrent reset and writes */
-       if (sdkp->zones_wlock &&
-           test_and_set_bit(zno, sdkp->zones_wlock))
-               return BLKPREP_DEFER;
-
        cmd->cmd_len = 16;
        memset(cmd->cmnd, 0, cmd->cmd_len);
        cmd->cmnd[0] = ZBC_OUT;
@@ -324,38 +318,34 @@ void sd_zbc_complete(struct scsi_cmnd *cmd,
        struct request *rq = cmd->request;
 
        switch (req_op(rq)) {
+       case REQ_OP_ZONE_RESET:
+
+               if (result &&
+                   sshdr->sense_key == ILLEGAL_REQUEST &&
+                   sshdr->asc == 0x24)
+                       /*
+                        * INVALID FIELD IN CDB error: reset of a conventional
+                        * zone was attempted. Nothing to worry about, so be
+                        * quiet about the error.
+                        */
+                       rq->rq_flags |= RQF_QUIET;
+               break;
+
        case REQ_OP_WRITE:
        case REQ_OP_WRITE_SAME:
-       case REQ_OP_ZONE_RESET:
 
                /* Unlock the zone */
                sd_zbc_write_unlock_zone(cmd);
 
-               if (!result ||
-                   sshdr->sense_key != ILLEGAL_REQUEST)
-                       break;
-
-               switch (sshdr->asc) {
-               case 0x24:
-                       /*
-                        * INVALID FIELD IN CDB error: For a zone reset,
-                        * this means that a reset of a conventional
-                        * zone was attempted. Nothing to worry about in
-                        * this case, so be quiet about the error.
-                        */
-                       if (req_op(rq) == REQ_OP_ZONE_RESET)
-                               rq->rq_flags |= RQF_QUIET;
-                       break;
-               case 0x21:
+               if (result &&
+                   sshdr->sense_key == ILLEGAL_REQUEST &&
+                   sshdr->asc == 0x21)
                        /*
                         * INVALID ADDRESS FOR WRITE error: It is unlikely that
                         * retrying write requests failed with any kind of
                         * alignement error will result in success. So don't.
                         */
                        cmd->allowed = 0;
-                       break;
-               }
-
                break;
 
        case REQ_OP_ZONE_REPORT: