When the scsi device status is offline, mode sense command will return a result with only DID_NO_CONNECT set. Then in sd_read_write_protect_flag(), only status byte of the result is checked, we still consider the command returned good, and read sdkp->write_prot from the buffer. And because of bug [1], garbage data is copied to the buffer, the disk sometimes be set readonly. When the scsi device is set running again, users cannot write data to the disk. So return 0 in scsi_status_is_good() for offline devices to indicate that the command has failed. And move scsi_status_is_good() down after the definition of DID_NO_CONNECT so that we can compile fine. [1] https://patchwork.kernel.org/project/linux-block/patch/20210318122621.330010-1-yanaijie@xxxxxxxxxx/ Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx> --- include/scsi/scsi.h | 54 +++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 26 deletions(-) diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index e75cca25338a..d7bfbfde0ea5 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -30,32 +30,6 @@ enum scsi_timeouts { */ #define SCAN_WILD_CARD ~0 -/** scsi_status_is_good - check the status return. - * - * @status: the status passed up from the driver (including host and - * driver components) - * - * This returns true for known good conditions that may be treated as - * command completed normally - */ -static inline int scsi_status_is_good(int status) -{ - /* - * FIXME: bit0 is listed as reserved in SCSI-2, but is - * significant in SCSI-3. For now, we follow the SCSI-2 - * behaviour and ignore reserved bits. - */ - status &= 0xfe; - return ((status == SAM_STAT_GOOD) || - (status == SAM_STAT_CONDITION_MET) || - /* Next two "intermediate" statuses are obsolete in SAM-4 */ - (status == SAM_STAT_INTERMEDIATE) || - (status == SAM_STAT_INTERMEDIATE_CONDITION_MET) || - /* FIXME: this is obsolete in SAM-3 */ - (status == SAM_STAT_COMMAND_TERMINATED)); -} - - /* * standard mode-select header prepended to all mode-select commands */ @@ -276,4 +250,32 @@ static inline int scsi_is_wlun(u64 lun) /* Used to obtain the PCI location of a device */ #define SCSI_IOCTL_GET_PCI 0x5387 +/** scsi_status_is_good - check the status return. + * + * @status: the status passed up from the driver (including host and + * driver components) + * + * This returns true for known good conditions that may be treated as + * command completed normally + */ +static inline int scsi_status_is_good(int status) +{ + if (host_byte(status) == DID_NO_CONNECT) + return 0; + + /* + * FIXME: bit0 is listed as reserved in SCSI-2, but is + * significant in SCSI-3. For now, we follow the SCSI-2 + * behaviour and ignore reserved bits. + */ + status &= 0xfe; + return ((status == SAM_STAT_GOOD) || + (status == SAM_STAT_CONDITION_MET) || + /* Next two "intermediate" statuses are obsolete in SAM-4 */ + (status == SAM_STAT_INTERMEDIATE) || + (status == SAM_STAT_INTERMEDIATE_CONDITION_MET) || + /* FIXME: this is obsolete in SAM-3 */ + (status == SAM_STAT_COMMAND_TERMINATED)); +} + #endif /* _SCSI_SCSI_H */ -- 2.25.4
