From 001aac257cf8adbe90cdcba6e07f8d12dfc8fa6b Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Sun, 2 Dec 2007 19:10:40 +0200 Subject: [PATCH] [SCSI] sd,sr: add early detection of medium not present The current scsi_test_unit_ready() is updated to return sense code information (in struct scsi_sense_hdr). The sd and sr drivers are changed to interpret the sense code return asc 0x3a as no media and adjust the device status accordingly. Signed-off-by: James Bottomley --- drivers/scsi/scsi_ioctl.c | 2 +- drivers/scsi/scsi_lib.c | 46 ++++++++++++++++++++++++++++++++++++++-------- drivers/scsi/sd.c | 13 ++++++++++--- drivers/scsi/sr.c | 19 +++++++++++++------ include/scsi/scsi_device.h | 2 +- 5 files changed, 63 insertions(+), 19 deletions(-) diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c index 83e1447..28b19ef 100644 --- a/drivers/scsi/scsi_ioctl.c +++ b/drivers/scsi/scsi_ioctl.c @@ -244,7 +244,7 @@ int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); case SCSI_IOCTL_TEST_UNIT_READY: return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT, - NORMAL_RETRIES); + NORMAL_RETRIES, NULL); case SCSI_IOCTL_START_UNIT: scsi_cmd[0] = START_STOP; scsi_cmd[1] = 0; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index aa17e71..db52222 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1973,27 +1973,57 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, } EXPORT_SYMBOL(scsi_mode_sense); +/** + * scsi_test_unit_ready - test if unit is ready + * @sdev: scsi device to change the state of. + * @timeout: command timeout + * @retries: number of retries before failing + * @sshdr_external: Optional pointer to struct scsi_sense_hdr for + * returning sense. Make sure that this is cleared before passing + * in. + * + * Returns zero if unsuccessful or an error if TUR failed. For + * removable media, a return of NOT_READY or UNIT_ATTENTION is + * translated to success, with the ->changed flag updated. + **/ int -scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries) +scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, + struct scsi_sense_hdr *sshdr_external) { char cmd[] = { TEST_UNIT_READY, 0, 0, 0, 0, 0, }; - struct scsi_sense_hdr sshdr; + struct scsi_sense_hdr *sshdr; int result; - - result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, &sshdr, - timeout, retries); + + if (!sshdr_external) + sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); + else + sshdr = sshdr_external; + + /* try to eat the UNIT_ATTENTION if there are enough retries */ + do { + result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, + timeout, retries); + } while ((driver_byte(result) & DRIVER_SENSE) && + sshdr && sshdr->sense_key == UNIT_ATTENTION && + --retries); + + if (!sshdr) + /* could not allocate sense buffer, so can't process it */ + return result; if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { - if ((scsi_sense_valid(&sshdr)) && - ((sshdr.sense_key == UNIT_ATTENTION) || - (sshdr.sense_key == NOT_READY))) { + if ((scsi_sense_valid(sshdr)) && + ((sshdr->sense_key == UNIT_ATTENTION) || + (sshdr->sense_key == NOT_READY))) { sdev->changed = 1; result = 0; } } + if (!sshdr_external) + kfree(sshdr); return result; } EXPORT_SYMBOL(scsi_test_unit_ready); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 18343a6..212f6bc 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -736,6 +736,7 @@ static int sd_media_changed(struct gendisk *disk) { struct scsi_disk *sdkp = scsi_disk(disk); struct scsi_device *sdp = sdkp->device; + struct scsi_sense_hdr *sshdr = NULL; int retval; SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n")); @@ -766,8 +767,11 @@ static int sd_media_changed(struct gendisk *disk) */ retval = -ENODEV; - if (scsi_block_when_processing_errors(sdp)) - retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES); + if (scsi_block_when_processing_errors(sdp)) { + sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); + retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES, + sshdr); + } /* * Unable to test, unit probably not ready. This usually @@ -775,7 +779,9 @@ static int sd_media_changed(struct gendisk *disk) * and we will figure it out later once the drive is * available again. */ - if (retval) { + if (retval || (scsi_sense_valid(sshdr) && + /* 0x3a is medium not present */ + sshdr->asc == 0x3a)) { set_media_not_present(sdkp); retval = 1; goto out; @@ -794,6 +800,7 @@ out: if (retval != sdkp->previous_state) sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL); sdkp->previous_state = retval; + kfree(sshdr); return retval; } diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 7702681..896be4a 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -179,18 +179,24 @@ static int sr_media_change(struct cdrom_device_info *cdi, int slot) { struct scsi_cd *cd = cdi->handle; int retval; + struct scsi_sense_hdr *sshdr; if (CDSL_CURRENT != slot) { /* no changer support */ return -EINVAL; } - retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES); - if (retval) { - /* Unable to test, unit probably not ready. This usually - * means there is no disc in the drive. Mark as changed, - * and we will figure it out later once the drive is - * available again. */ + sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); + retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, + sshdr); + if (retval || (scsi_sense_valid(sshdr) && + /* 0x3a is medium not present */ + sshdr->asc == 0x3a)) { + /* Media not present or unable to test, unit probably not + * ready. This usually means there is no disc in the drive. + * Mark as changed, and we will figure it out later once + * the drive is available again. + */ cd->device->changed = 1; /* This will force a flush, if called from check_disk_change */ retval = 1; @@ -213,6 +219,7 @@ out: sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL); cd->previous_state = retval; + kfree(sshdr); return retval; } diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 45bb12b..e0c645a 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -295,7 +295,7 @@ extern int scsi_mode_select(struct scsi_device *sdev, int pf, int sp, struct scsi_mode_data *data, struct scsi_sense_hdr *); extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout, - int retries); + int retries, struct scsi_sense_hdr *sshdr); extern int scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state); extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, -- 2.7.4