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authorMartin K. Petersen <martin.petersen@oracle.com>2013-06-07 06:15:55 +0400
committerJames Bottomley <JBottomley@Parallels.com>2013-06-27 04:56:18 +0400
commit66c28f97120e8a621afd5aa7a31c4b85c547d33d (patch)
treeec0f4ee9b3a34264f1d9c33df28ec89fbaf6561a /drivers/scsi/scsi.c
parent5d65f91896197bd047f97ed8e7792b06de491eac (diff)
downloadlinux-66c28f97120e8a621afd5aa7a31c4b85c547d33d.tar.xz
[SCSI] sd: Update WRITE SAME heuristics
SATA drives located behind a SAS controller would incorrectly receive WRITE SAME commands. Tweak the heuristics so that: - If REPORT SUPPORTED OPERATION CODES is provided we will use that to choose between WRITE SAME(16), WRITE SAME(10) and disabled. This also fixes an issue with the old code which would issue WRITE SAME(10) despite the command not being whitelisted in REPORT SUPPORTED OPERATION CODES. - If REPORT SUPPORTED OPERATION CODES is not provided we will fall back to WRITE SAME(10) unless the device has an ATA Information VPD page. The assumption is that a SATL which is smart enough to implement WRITE SAME would also provide REPORT SUPPORTED OPERATION CODES. To facilitate the new heuristics scsi_report_opcode() has been modified to so we can distinguish between "operation not supported" and "RSOC not supported". Reported-by: H. Peter Anvin <hpa@zytor.com> Tested-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/scsi.c')
-rw-r--r--drivers/scsi/scsi.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 2c0d0ec8150b..3b1ea34e1f5a 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -1070,8 +1070,8 @@ EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
* @opcode: opcode for command to look up
*
* Uses the REPORT SUPPORTED OPERATION CODES to look up the given
- * opcode. Returns 0 if RSOC fails or if the command opcode is
- * unsupported. Returns 1 if the device claims to support the command.
+ * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
+ * unsupported and 1 if the device claims to support the command.
*/
int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
unsigned int len, unsigned char opcode)
@@ -1081,7 +1081,7 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
int result;
if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
- return 0;
+ return -EINVAL;
memset(cmd, 0, 16);
cmd[0] = MAINTENANCE_IN;
@@ -1097,7 +1097,7 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
if (result && scsi_sense_valid(&sshdr) &&
sshdr.sense_key == ILLEGAL_REQUEST &&
(sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
- return 0;
+ return -EINVAL;
if ((buffer[1] & 3) == 3) /* Command supported */
return 1;