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authorMike Christie <michaelc@cs.wisc.edu>2015-04-20 22:42:24 -0500
committerSasha Levin <sasha.levin@oracle.com>2015-08-06 14:49:50 -0400
commitbda69f1aaee53837ba22e2ea149219dff486f542 (patch)
parente8780dac8cd1f84f7c31c68bb87c18b6141afca7 (diff)
SCSI: add 1024 max sectors black list flag
[ Upstream commit 35e9a9f93994d7f7d12afa41169c7ba05513721b ] This works around a issue with qnap iscsi targets not handling large IOs very well. The target returns: VPD INQUIRY: Block limits page (SBC) Maximum compare and write length: 1 blocks Optimal transfer length granularity: 1 blocks Maximum transfer length: 4294967295 blocks Optimal transfer length: 4294967295 blocks Maximum prefetch, xdread, xdwrite transfer length: 0 blocks Maximum unmap LBA count: 8388607 Maximum unmap block descriptor count: 1 Optimal unmap granularity: 16383 Unmap granularity alignment valid: 0 Unmap granularity alignment: 0 Maximum write same length: 0xffffffff blocks Maximum atomic transfer length: 0 Atomic alignment: 0 Atomic transfer length granularity: 0 and it is *sometimes* able to handle at least one IO of size up to 8 MB. We have seen in traces where it will sometimes work, but other times it looks like it fails and it looks like it returns failures if we send multiple large IOs sometimes. Also it looks like it can return 2 different errors. It will sometimes send iscsi reject errors indicating out of resources or it will send invalid cdb illegal requests check conditions. And then when it sends iscsi rejects it does not seem to handle retries when there are command sequence holes, so I could not just add code to try and gracefully handle that error code. The problem is that we do not have a good contact for the company, so we are not able to determine under what conditions it returns which error and why it sometimes works. So, this patch just adds a new black list flag to set targets like this to the old max safe sectors of 1024. The max_hw_sectors changes added in 3.19 caused this regression, so I also ccing stable. Reported-by: Christian Hesse <list@eworm.de> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
3 files changed, 8 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index 262ab837a704..9f77d23239a2 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -226,6 +226,7 @@ static struct {
{"Promise", "VTrak E610f", NULL, BLIST_SPARSELUN | BLIST_NO_RSOC},
{"Promise", "", NULL, BLIST_SPARSELUN},
+ {"QNAP", "iSCSI Storage", NULL, BLIST_MAX_1024},
{"QUANTUM", "XP34301", "1071", BLIST_NOTQ},
{"SanDisk", "ImageMate CF-SD1", NULL, BLIST_FORCELUN},
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index ba3f1e8d0d57..f49cb534a829 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -901,6 +901,12 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
if (*bflags & BLIST_MAX_512)
blk_queue_max_hw_sectors(sdev->request_queue, 512);
+ /*
+ * Max 1024 sector transfer length for targets that report incorrect
+ * max/optimal lengths and relied on the old block layer safe default
+ */
+ else if (*bflags & BLIST_MAX_1024)
+ blk_queue_max_hw_sectors(sdev->request_queue, 1024);
* Some devices may not want to have a start command automatically
diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
index 183eaab7c380..96e3f56519e7 100644
--- a/include/scsi/scsi_devinfo.h
+++ b/include/scsi/scsi_devinfo.h
@@ -36,5 +36,6 @@
for sequential scan */
#define BLIST_TRY_VPD_PAGES 0x10000000 /* Attempt to read VPD pages */
#define BLIST_NO_RSOC 0x20000000 /* don't try to issue RSOC */
+#define BLIST_MAX_1024 0x40000000 /* maximum 1024 sector cdb length */