From 54b2b50c20a61b51199bedb6e5d2f8ec2568fb43 Mon Sep 17 00:00:00 2001 From: Martin K. Petersen Date: Wed, 23 Oct 2013 06:25:40 -0400 Subject: [SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers Some host adapters do not pass commands through to the target disk directly. Instead they provide an emulated target which may or may not accurately report its capabilities. In some cases the physical device characteristics are reported even when the host adapter is processing commands on the device's behalf. This can lead to adapter firmware hangs or excessive I/O errors. This patch disables WRITE SAME for devices connected to host adapters that provide an emulated target. Driver writers can disable WRITE SAME by setting the no_write_same flag in the host adapter template. [jejb: fix up rejections due to eh_deadline patch] Signed-off-by: Martin K. Petersen Cc: stable@kernel.org Signed-off-by: James Bottomley --- drivers/ata/libata-scsi.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/ata') diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index db6dfcfa3e2e..ab58556d347c 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3625,6 +3625,7 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht) shost->max_lun = 1; shost->max_channel = 1; shost->max_cmd_len = 16; + shost->no_write_same = 1; /* Schedule policy is determined by ->qc_defer() * callback and it needs to see every deferred qc. -- cgit v1.2.3