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authorIvan Mironov <mironov.ivan@gmail.com>2018-12-23 12:41:58 +0500
committerMartin K. Petersen <martin.petersen@oracle.com>2019-01-08 21:57:25 -0500
commit44759979a49bfd2d20d789add7fa81a21eb1a4ab (patch)
tree888fc1a1fc190ae7683aad095090ab03ed5a60fe /drivers/scsi
parentbfeffd155283772bbe78c6a05dec7c0128ee500c (diff)
scsi: sd: Fix cache_type_store()
Changing of caching mode via /sys/devices/.../scsi_disk/.../cache_type may fail if device responds to MODE SENSE command with DPOFUA flag set, and then checks this flag to be not set on MODE SELECT command. In this scenario, when trying to change cache_type, write always fails: # echo "none" >cache_type bash: echo: write error: Invalid argument And following appears in dmesg: [13007.865745] sd 1:0:1:0: [sda] Sense Key : Illegal Request [current] [13007.865753] sd 1:0:1:0: [sda] Add. Sense: Invalid field in parameter list From SBC-4 r15, 6.5.1 "Mode pages overview", description of DEVICE-SPECIFIC PARAMETER field in the mode parameter header: ... The write protect (WP) bit for mode data sent with a MODE SELECT command shall be ignored by the device server. ... The DPOFUA bit is reserved for mode data sent with a MODE SELECT command. ... The remaining bits in the DEVICE-SPECIFIC PARAMETER byte are also reserved and shall be set to zero. [mkp: shuffled commentary to commit description] Cc: stable@vger.kernel.org Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/sd.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a1a44f52e0e8..b2da8a00ec33 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -206,6 +206,12 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
sp = buffer_data[0] & 0x80 ? 1 : 0;
buffer_data[0] &= ~0x80;
+ /*
+ * Ensure WP, DPOFUA, and RESERVED fields are cleared in
+ * received mode parameter buffer before doing MODE SELECT.
+ */
+ data.device_specific = 0;
+
if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
SD_MAX_RETRIES, &data, &sshdr)) {
if (scsi_sense_valid(&sshdr))