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authorMartin K. Petersen <martin.petersen@oracle.com>2012-09-18 20:19:32 +0400
committerJames Bottomley <JBottomley@Parallels.com>2012-11-14 10:45:42 +0400
commit5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd (patch)
treea352bab202b6cb40f234bd2fd306b54776543e8b /drivers/scsi/scsi_lib.c
parent26e85fcd15f68b57d9ba645cd3591117a8ac0e05 (diff)
downloadlinux-5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd.tar.xz
[SCSI] sd: Implement support for WRITE SAME
Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk driver. - We set the default maximum to 0xFFFF because there are several devices out there that only support two-byte block counts even with WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK LIMITS VPD. - max_write_same_blocks can be overriden per-device basis in sysfs. - The UNMAP discovery heuristics remain unchanged but the discard limits are tweaked to match the "real" WRITE SAME commands. - In the error handling logic we now distinguish between WRITE SAME with and without UNMAP set. The discovery process heuristics are: - If the device reports a SCSI level of SPC-3 or greater we'll issue READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is supported. If that's the case we will use it. - If the device supports the block limits VPD and reports a MAXIMUM WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16). - Otherwise we will use WRITE SAME(10) unless the target LBA is beyond 0xFFFFFFFF or the block count exceeds 0xFFFF. - no_write_same is set for ATA, FireWire and USB. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index da36a3a81a9e..9032e910bca3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -900,11 +900,23 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
action = ACTION_FAIL;
error = -EILSEQ;
/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
- } else if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
- (cmd->cmnd[0] == UNMAP ||
- cmd->cmnd[0] == WRITE_SAME_16 ||
- cmd->cmnd[0] == WRITE_SAME)) {
- description = "Discard failure";
+ } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
+ switch (cmd->cmnd[0]) {
+ case UNMAP:
+ description = "Discard failure";
+ break;
+ case WRITE_SAME:
+ case WRITE_SAME_16:
+ if (cmd->cmnd[1] & 0x8)
+ description = "Discard failure";
+ else
+ description =
+ "Write same failure";
+ break;
+ default:
+ description = "Invalid command failure";
+ break;
+ }
action = ACTION_FAIL;
error = -EREMOTEIO;
} else