diff options
| author | Sujit Reddy Thumma <sthumma@codeaurora.org> | 2014-08-11 15:40:37 +0300 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-09-15 16:01:57 -0700 |
| commit | 2eefd57b97609949ae40952da2dea338e7d9a125 (patch) | |
| tree | 9010e184d6af69458b34cf6239ba2e4ba6ef8c9c /drivers/scsi/sd.c | |
| parent | 74cf298fedfcb732335cae5d157e95295e87cf2a (diff) | |
sd: Avoid sending medium write commands if device is write protected
The SYNCHRONIZE_CACHE command is a medium write command and hence can
fail when the device is write protected. Avoid sending such commands by
making sure that write-cache-enable is disabled even though the device
claim to support it.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 2c2041ca4b70..aa43496b7b93 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -185,7 +185,7 @@ cache_type_store(struct device *dev, struct device_attribute *attr, if (ct < 0) return -EINVAL; rcd = ct & 0x01 ? 1 : 0; - wce = ct & 0x02 ? 1 : 0; + wce = (ct & 0x02) && !sdkp->write_prot ? 1 : 0; if (sdkp->cache_override) { sdkp->WCE = wce; @@ -2490,6 +2490,10 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer) sdkp->DPOFUA = 0; } + /* No cache flush allowed for write protected devices */ + if (sdkp->WCE && sdkp->write_prot) + sdkp->WCE = 0; + if (sdkp->first_scan || old_wce != sdkp->WCE || old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA) sd_printk(KERN_NOTICE, sdkp, |