During ALUA state transitions the device might return a sense code 02/04/0a (Logical unit not accessible, asymmetric access state transition). As this is a transient error we should just retry the READ CAPACITY call after 1 second until the state transition finishes and the correct capacity can be returned. At the same time we should break out of the loop after 2 minutes to avoid unbounded retries.
Signed-off-by: Hannes Reinecke <[email protected]> --- drivers/scsi/sd.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3b2fcb4..f45b8fe 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1934,6 +1934,7 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp, #endif #define READ_CAPACITY_RETRIES_ON_RESET 10 +#define READ_CAPACITY_RETRIES_ON_TRANSITION 120 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, unsigned char *buffer) @@ -1943,6 +1944,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, int sense_valid = 0; int the_result; int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET; + int transition_retries = READ_CAPACITY_RETRIES_ON_TRANSITION; unsigned int alignment; unsigned long long lba; unsigned sector_size; @@ -1981,6 +1983,15 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, * give it one more chance */ if (--reset_retries > 0) continue; + if (sense_valid && + sshdr.sense_key == NOT_READY && + sshdr.asc == 0x04 && sshdr.ascq == 0x0A) { + /* ALUA state transition; retry after delay */ + if (--transition_retries > 0) { + msleep(1000); + continue; + } + } } retries--; @@ -2039,6 +2050,7 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp, int sense_valid = 0; int the_result; int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET; + int transition_retries = READ_CAPACITY_RETRIES_ON_TRANSITION; sector_t lba; unsigned sector_size; @@ -2063,6 +2075,15 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp, * give it one more chance */ if (--reset_retries > 0) continue; + if (sense_valid && + sshdr.sense_key == NOT_READY && + sshdr.asc == 0x04 && sshdr.ascq == 0x0A) { + /* ALUA state transition; retry after delay */ + if (--transition_retries > 0) { + msleep(1000); + continue; + } + } } retries--; -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
