| From foo@baz Thu May 24 11:23:00 CEST 2018 |
| From: Jeremy Cline <jeremy@jcline.org> |
| Date: Tue, 6 Mar 2018 21:47:32 +0000 |
| Subject: scsi: sd: Keep disk read-only when re-reading partition |
| |
| From: Jeremy Cline <jeremy@jcline.org> |
| |
| [ Upstream commit 20bd1d026aacc5399464f8328f305985c493cde3 ] |
| |
| If the read-only flag is true on a SCSI disk, re-reading the partition |
| table sets the flag back to false. |
| |
| To observe this bug, you can run: |
| |
| 1. blockdev --setro /dev/sda |
| 2. blockdev --rereadpt /dev/sda |
| 3. blockdev --getro /dev/sda |
| |
| This commit reads the disk's old state and combines it with the device |
| disk-reported state rather than unconditionally marking it as RW. |
| |
| Reported-by: Li Ning <lining916740672@icloud.com> |
| Signed-off-by: Jeremy Cline <jeremy@jcline.org> |
| Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/scsi/sd.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/scsi/sd.c |
| +++ b/drivers/scsi/sd.c |
| @@ -2401,6 +2401,7 @@ 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); |
| @@ -2441,7 +2442,7 @@ 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); |
| + set_disk_ro(sdkp->disk, sdkp->write_prot || disk_ro); |
| if (sdkp->first_scan || old_wp != sdkp->write_prot) { |
| sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n", |
| sdkp->write_prot ? "on" : "off"); |
