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| author | Martin K. Petersen <martin.petersen@oracle.com> | 2012-09-18 12:19:32 -0400 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2012-11-13 22:45:42 -0800 |
| commit | 5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd (patch) | |
| tree | a352bab202b6cb40f234bd2fd306b54776543e8b /drivers/scsi/scsi_lib.c | |
| parent | 26e85fcd15f68b57d9ba645cd3591117a8ac0e05 (diff) | |
| download | linux-5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd.tar.gz | |
[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.c | 22 |
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 |