SCSI/SD: clearer output of disk cache state

PATCH In review Luben Tuikov 5 participants 9 messages Nov 4, 2006 – Nov 15, 2006 SCSI

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Luben Tuikov

author

2006-11-04 19:54 UTC #0 lore raw

PATCH 1/1 SCSI/SD: clearer output of disk cache state

Signed-off-by Luben Tuikov <[email protected]>

---
 drivers/scsi/sd.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

This patch is 8 months old.

Luben

drivers/scsi/sd.c +7 ~~-10~~

index 9d98723..f157747 100644
@@ -1354,11 +1354,6 @@ sd_read_cache_type(struct scsi_disk *sdk
 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
 
 	if (scsi_status_is_good(res)) {
-		const char *types[] = {
-			"write through", "none", "write back",
-			"write back, no read (daft)"
-		};
-		int ct = 0;
 		int offset = data.header_length + data.block_descriptor_length;
 
 		if (offset >= SD_BUF_SIZE - 2) {

@@ -1387,11 +1382,13 @@ sd_read_cache_type(struct scsi_disk *sdk
 			sdkp->DPOFUA = 0;
 		}
 
-		ct =  sdkp->RCD + 2*sdkp->WCE;
-
-		printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n",
-		       diskname, types[ct],
-		       sdkp->DPOFUA ? " w/ FUA" : "");
+		printk(KERN_NOTICE "SCSI device %s: "
+		       "write cache: %s, read cache: %s, %s\n",
+		       diskname,
+		       sdkp->WCE ? "enabled" : "disabled",
+		       sdkp->RCD ? "disabled" : "enabled",
+		       sdkp->DPOFUA ? "supports DPO and FUA"
+		       : "doesn't support DPO or FUA");
 
 		return;
 	}

Signature · 1 line

1.4.3.3.g8478

James Bottomley

2006-11-04 23:12 UTC #2 lore raw

In reply to Luben Tuikov

Quoted 6 lines · Luben Tuikov

Signed-off-by Luben Tuikov <[email protected]>
---
 drivers/scsi/sd.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)
This patch is 8 months old.

Um:

patching file drivers/scsi/sd.c
Hunk #1 FAILED at 1354.
Hunk #2 FAILED at 1382.
2 out of 2 hunks FAILED -- saving rejects to file drivers/scsi/sd.c.rej

I think the code you're trying to change has altered a bit in the latest kernels.

James

Luben Tuikov

author

2006-11-05 00:45 UTC #3 lore raw

Quoted 10 lines · --- James Bottomley

Quoted 6 lines · Luben Tuikov
Signed-off-by Luben Tuikov <[email protected]>
---
 drivers/scsi/sd.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)
This patch is 8 months old.
Um:

Quoted 7 lines

patching file drivers/scsi/sd.c
Hunk #1 FAILED at 1354.
Hunk #2 FAILED at 1382.
2 out of 2 hunks FAILED -- saving rejects to file drivers/scsi/sd.c.rej
I think the code you're trying to change has altered a bit in the latest kernels.

Re-based:

Signed-off-by Luben Tuikov <[email protected]>

---

 drivers/scsi/sd.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

drivers/scsi/sd.c +7 -6

index 84ff203..ffbd021 100644
@@ -1467,7 +1467,6 @@ sd_read_cache_type(struct scsi_disk *sdk
        res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
 
        if (scsi_status_is_good(res)) {
-               int ct = 0;
                int offset = data.header_length + data.block_descriptor_length;
 
                if (offset >= SD_BUF_SIZE - 2) {

@@ -1496,11 +1495,13 @@ sd_read_cache_type(struct scsi_disk *sdk
                        sdkp->DPOFUA = 0;
                }
 
-               ct =  sdkp->RCD + 2*sdkp->WCE;
-
-               printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n",
-                      diskname, sd_cache_types[ct],
-                      sdkp->DPOFUA ? " w/ FUA" : "");
+               printk(KERN_NOTICE "SCSI device %s: "
+                      "write cache: %s, read cache: %s, %s\n",
+                      diskname,
+                      sdkp->WCE ? "enabled" : "disabled",
+                      sdkp->RCD ? "disabled" : "enabled",
+                      sdkp->DPOFUA ? "supports DPO and FUA"
+                      : "doesn't support DPO or FUA");
 
                return;
        }

Jeff Garzik

2006-11-05 03:57 UTC #4 lore raw

Quoted 15 lines · Luben Tuikov

Quoted 14 lines · --- James Bottomley
Quoted 6 lines · Luben Tuikov
Signed-off-by Luben Tuikov <[email protected]>
---
 drivers/scsi/sd.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)
This patch is 8 months old.
Um:
patching file drivers/scsi/sd.c
Hunk #1 FAILED at 1354.
Hunk #2 FAILED at 1382.
2 out of 2 hunks FAILED -- saving rejects to file drivers/scsi/sd.c.rej

Quoted 6 lines

Quoted 2 lines
I think the code you're trying to change has altered a bit in the latest kernels.
Re-based:
Signed-off-by Luben Tuikov <[email protected]>

ACK

James Bottomley

2006-11-05 05:37 UTC #5 lore raw

In reply to Luben Tuikov

Quoted 1 line · Luben Tuikov

Re-based:

Thanks,

If you want to go the whole hog on this one, we probably also need WCE and RCD files (taking 1 or 0) for the scsi_disk class and a date in the feature removal file for dumping the cache_type file.

James

Douglas Gilbert

2006-11-05 14:47 UTC #6 lore raw

In reply to Luben Tuikov

Quoted 47 lines · Luben Tuikov

Quoted 9 lines · --- James Bottomley

Quoted 6 lines · Luben Tuikov
Signed-off-by Luben Tuikov <[email protected]>
---
 drivers/scsi/sd.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)
This patch is 8 months old.
Um:

Quoted 7 lines

patching file drivers/scsi/sd.c
Hunk #1 FAILED at 1354.
Hunk #2 FAILED at 1382.
2 out of 2 hunks FAILED -- saving rejects to file drivers/scsi/sd.c.rej
I think the code you're trying to change has altered a bit in the latest kernels.

Re-based:

Signed-off-by Luben Tuikov <[email protected]>

---

 drivers/scsi/sd.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

drivers/scsi/sd.c +0 -6

index 84ff203..ffbd021 100644
@@ -1467,7 +1467,6 @@ sd_read_cache_type(struct scsi_disk *sdk
        res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
 
        if (scsi_status_is_good(res)) {
-               int ct = 0;
                int offset = data.header_length + data.block_descriptor_length;
 
                if (offset >= SD_BUF_SIZE - 2) {

@@ -1496,11 +1495,13 @@ sd_read_cache_type(struct scsi_disk *sdk
                        sdkp->DPOFUA = 0;
                }
 
-               ct =  sdkp->RCD + 2*sdkp->WCE;
-
-               printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n",
-                      diskname, sd_cache_types[ct],
-                      sdkp->DPOFUA ? " w/ FUA" : "");

drivers/scsi/sd.c sd_read_cache_type(struct scsi_disk *sdk · line 1507

Quoted 10 lines

drivers/scsi/sd.c +7 -0

+               printk(KERN_NOTICE "SCSI device %s: "
+                      "write cache: %s, read cache: %s, %s\n",
+                      diskname,
+                      sdkp->WCE ? "enabled" : "disabled",
+                      sdkp->RCD ? "disabled" : "enabled",
+                      sdkp->DPOFUA ? "supports DPO and FUA"
+                      : "doesn't support DPO or FUA");
 
                return;
        }

The definition of the DPOFUA flag (in the block descriptor returned by MODE SENSE for direct access devices) is a bit fuzzy in practice. When I queried the t10 reflector a member from a disk company said it should be interpreted as ... we support DPO and/or FUA.

I also noticed that one disk manufacturer's unit attention mode page had a bit to disable FUA (force unit access). So you can set the FUA bit (in a READ or WRITE), we will ignore it! The associated note says that it improves performance :-)

Doug Gilbert

James Bottomley

2006-11-15 20:26 UTC #7 lore raw

In reply to Luben Tuikov

Quoted 3 lines · Luben Tuikov

Re-based:
Signed-off-by Luben Tuikov <[email protected]>

It still won't apply ... this time it looks like a mailer tab->space conversion problem.

James

Luben Tuikov

author

2006-11-15 20:47 UTC #8 lore raw

Quoted 7 lines · --- James Bottomley

Quoted 3 lines · Luben Tuikov
Re-based:
Signed-off-by Luben Tuikov <[email protected]>
It still won't apply ... this time it looks like a mailer tab->space conversion problem.

Attached.

Luben

Signed-off-by Luben Tuikov <[email protected]>

drivers/scsi/sd.c +7 -6

index 84ff203..ffbd021 100644
@@ -1467,7 +1467,6 @@ sd_read_cache_type(struct scsi_disk *sdk
 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
 
 	if (scsi_status_is_good(res)) {
-		int ct = 0;
 		int offset = data.header_length + data.block_descriptor_length;
 
 		if (offset >= SD_BUF_SIZE - 2) {

@@ -1496,11 +1495,13 @@ sd_read_cache_type(struct scsi_disk *sdk
 			sdkp->DPOFUA = 0;
 		}
 
-		ct =  sdkp->RCD + 2*sdkp->WCE;
-
-		printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n",
-		       diskname, sd_cache_types[ct],
-		       sdkp->DPOFUA ? " w/ FUA" : "");
+		printk(KERN_NOTICE "SCSI device %s: "
+		       "write cache: %s, read cache: %s, %s\n",
+		       diskname,
+		       sdkp->WCE ? "enabled" : "disabled",
+		       sdkp->RCD ? "disabled" : "enabled",
+		       sdkp->DPOFUA ? "supports DPO and FUA"
+		       : "doesn't support DPO or FUA");
 
 		return;
 	}