[PATCH 3.11 019/233] [SCSI] sd: Reduce buffer size for vpd request

From: Luis Henriques
Date: Fri Feb 07 2014 - 08:20:27 EST -stable review patch. If anyone has any objections, please let me know.


From: Bernd Schubert <bernd.schubert@xxxxxxxxxxxxxxxxxx>

commit af73623f5f10eb3832c87a169b28f7df040a875b upstream.

Somehow older areca firmware versions have issues with
scsi_get_vpd_page() and a large buffer, the firmware
seems to crash and the scsi error-handler will start endless
recovery retries.
Limiting the buf-size to 64-bytes fixes this issue with older
firmware versions (<1.49 for my controller).

Fixes a regression with areca controllers and older firmware versions
introduced by commit: 66c28f97120e8a621afd5aa7a31c4b85c547d33d

Reported-by: Nix <nix@xxxxxxxxxxxxx>
Tested-by: Nix <nix@xxxxxxxxxxxxx>
Signed-off-by: Bernd Schubert <bernd.schubert@xxxxxxxxxxxxxxxxxx>
Acked-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: James Bottomley <JBottomley@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
drivers/scsi/sd.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a873795..23e0673 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2644,13 +2644,16 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)

if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
+ /* too large values might cause issues with arcmsr */
+ int vpd_buf_len = 64;
sdev->no_report_opcodes = 1;

* CODES is unsupported and the device has an ATA
* Information VPD page (SAT).
- if (!scsi_get_vpd_page(sdev, 0x89, buffer, SD_BUF_SIZE))
+ if (!scsi_get_vpd_page(sdev, 0x89, buffer, vpd_buf_len))
sdev->no_write_same = 1;


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