[PATCH 4.4 079/241] Revert "scsi: sd: Keep disk read-only when re-reading partition"

From: Greg Kroah-Hartman
Date: Sun Jun 09 2019 - 13:03:35 EST

From: Martin K. Petersen <martin.petersen@xxxxxxxxxx>

commit 8acf608e602f6ec38b7cc37b04c80f1ce9a1a6cc upstream.

This reverts commit 20bd1d026aacc5399464f8328f305985c493cde3.

This patch introduced regressions for devices that come online in
read-only state and subsequently switch to read-write.

Given how the partition code is currently implemented it is not
possible to persist the read-only flag across a device revalidate
call. This may need to get addressed in the future since it is common
for user applications to proactively call BLKRRPART.

Reverting this commit will re-introduce a regression where a
device-initiated revalidate event will cause the admin state to be
forgotten. A separate patch will address this issue.

Fixes: 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading partition")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/scsi/sd.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2396,7 +2396,6 @@ sd_read_write_protect_flag(struct scsi_d
int res;
struct scsi_device *sdp = sdkp->device;
struct scsi_mode_data data;
- int disk_ro = get_disk_ro(sdkp->disk);
int old_wp = sdkp->write_prot;

set_disk_ro(sdkp->disk, 0);
@@ -2437,7 +2436,7 @@ sd_read_write_protect_flag(struct scsi_d
"Test WP failed, assume Write Enabled\n");
} else {
sdkp->write_prot = ((data.device_specific & 0x80) != 0);
- set_disk_ro(sdkp->disk, sdkp->write_prot || disk_ro);
+ set_disk_ro(sdkp->disk, sdkp->write_prot);
if (sdkp->first_scan || old_wp != sdkp->write_prot) {
sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
sdkp->write_prot ? "on" : "off");