On 07/08/2015 12:41 AM, Hannes Reinecke wrote:
> Device paths in ALUA state 'standby' do not necessarily support
> the READ_CAPACITY command. This patch adds a new flag 'invalid_capacity'
> to the scsi device, and rescans the device if an ALUA state
> change occurred.
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
> ---
> drivers/scsi/scsi_lib.c | 4 ++++
> drivers/scsi/sd.c | 19 ++++++++++++++-----
> include/scsi/scsi_device.h | 1 +
> 3 files changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index c005e42..d4245f0 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -2701,6 +2701,7 @@ static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
> envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
> break;
> case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
> + scsi_rescan_device(&sdev->sdev_gendev);
> envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
> break;
> case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
> @@ -2713,6 +2714,9 @@ static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
> envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
> break;
> case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
> + if (sdev->invalid_capacity)
> + scsi_rescan_device(&sdev->sdev_gendev);
> +
> envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
> break;
> default:
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 03fdfa9..7c0bdaa 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1983,14 +1983,18 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
> continue;
> if (sense_valid &&
> sshdr.sense_key == NOT_READY &&
> - sshdr.asc == 0x04 && sshdr.ascq == 0x0a)
> + sshdr.asc == 0x04 && sshdr.ascq == 0x0a) {
> /* Target port in transition */
> + sdp->invalid_capacity = 1;
> return 0;
> + }
> if (sense_valid &&
> sshdr.sense_key == NOT_READY &&
> - sshdr.asc == 0x04 && sshdr.ascq == 0x0b)
> + sshdr.asc == 0x04 && sshdr.ascq == 0x0b) {
> /* Target port in standy state */
> + sdp->invalid_capacity = 1;
> return 0;
> + }
> }
> retries--;
>
> @@ -2075,14 +2079,18 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
> continue;
> if (sense_valid &&
> sshdr.sense_key == NOT_READY &&
> - sshdr.asc == 0x04 && sshdr.ascq == 0x0a)
> + sshdr.asc == 0x04 && sshdr.ascq == 0x0a) {
> /* Target port in transition */
> + sdp->invalid_capacity = 1;
> return 0;
> + }
> if (sense_valid &&
> sshdr.sense_key == NOT_READY &&
> - sshdr.asc == 0x04 && sshdr.ascq == 0x0b)
> + sshdr.asc == 0x04 && sshdr.ascq == 0x0b) {
> /* Target port in standy state */
> + sdp->invalid_capacity = 1;
> return 0;
> + }
> }
> retries--;
>
> @@ -2199,7 +2207,8 @@ got_data:
> "assuming 512.\n");
> if (!sdkp->physical_block_size)
> sdkp->physical_block_size = sector_size;
> - }
> + } else
> + sdp->invalid_capacity = 0;
>
> if (sector_size != 512 &&
> sector_size != 1024 &&
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index 50c2a36..99bde5a 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -175,6 +175,7 @@ struct scsi_device {
> unsigned no_dif:1; /* T10 PI (DIF) should be disabled */
> unsigned broken_fua:1; /* Don't set FUA bit */
> unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */
> + unsigned invalid_capacity:1; /* READ_CAPACITY not supported */
Not sure I like the comment for the new field. How about something like
"current capacity unknown"?
>
> atomic_t disk_events_disable_depth; /* disable depth for disk events */
>
>
--
Lee Duncan
SUSE Labs
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