From 2bae0093cab4ee0a7a8728fdfc35b74569350863 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 18 Dec 2010 18:42:23 +0100 Subject: [PATCH] [SCSI] sd: implement sd_check_events() Replace sd_media_change() with sd_check_events(). * Move media removed logic into set_media_not_present() and media_not_present() and set sdev->changed iff an existing media is removed or the device indicates UNIT_ATTENTION. * Make sd_check_events() sets sdev->changed if previously missing media becomes present. * Event is reported only if sdev->changed is set. This makes media presence event reported if scsi_disk->media_present actually changed or the device indicated UNIT_ATTENTION. For backward compatibility, SDEV_EVT_MEDIA_CHANGE is generated each time sd_check_events() detects media change event. [jejb: fix boot failure] Signed-off-by: Tejun Heo Acked-by: Jens Axboe Signed-off-by: James Bottomley --- drivers/scsi/sd.c | 104 +++++++++++++++++++++++----------------------- drivers/scsi/sd.h | 1 - 2 files changed, 53 insertions(+), 52 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index b65e65aa07eb..7d257465bd98 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -990,30 +990,51 @@ out: static void set_media_not_present(struct scsi_disk *sdkp) { - sdkp->media_present = 0; - sdkp->capacity = 0; - sdkp->device->changed = 1; + if (sdkp->media_present) + sdkp->device->changed = 1; + + if (sdkp->device->removable) { + sdkp->media_present = 0; + sdkp->capacity = 0; + } +} + +static int media_not_present(struct scsi_disk *sdkp, + struct scsi_sense_hdr *sshdr) +{ + if (!scsi_sense_valid(sshdr)) + return 0; + + /* not invoked for commands that could return deferred errors */ + switch (sshdr->sense_key) { + case UNIT_ATTENTION: + case NOT_READY: + /* medium not present */ + if (sshdr->asc == 0x3A) { + set_media_not_present(sdkp); + return 1; + } + } + return 0; } /** - * sd_media_changed - check if our medium changed - * @disk: kernel device descriptor + * sd_check_events - check media events + * @disk: kernel device descriptor + * @clearing: disk events currently being cleared * - * Returns 0 if not applicable or no change; 1 if change + * Returns mask of DISK_EVENT_*. * * Note: this function is invoked from the block subsystem. **/ -static int sd_media_changed(struct gendisk *disk) +static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing) { 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")); - - if (!sdp->removable) - return 0; + SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n")); /* * If the device is offline, don't send any commands - just pretend as @@ -1043,40 +1064,37 @@ static int sd_media_changed(struct gendisk *disk) sshdr); } - if (retval) { + /* failed to execute TUR, assume media not present */ + if (host_byte(retval)) { set_media_not_present(sdkp); goto out; } + if (media_not_present(sdkp, sshdr)) + goto out; + /* * For removable scsi disk we have to recognise the presence - * of a disk in the drive. This is kept in the struct scsi_disk - * struct and tested at open ! Daniel Roche (dan@lectra.fr) + * of a disk in the drive. */ + if (!sdkp->media_present) + sdp->changed = 1; sdkp->media_present = 1; - out: /* - * Report a media change under the following conditions: + * sdp->changed is set under the following conditions: * - * Medium is present now and wasn't present before. - * Medium wasn't present before and is present now. - * Medium was present at all times, but it changed while - * we weren't looking (sdp->changed is set). + * Medium present state has changed in either direction. + * Device has indicated UNIT_ATTENTION. * - * If there was no medium before and there is no medium now then - * don't report a change, even if a medium was inserted and removed - * while we weren't looking. + * Report SDEV_EVT_MEDIA_CHANGE too for backward compatibility. */ - retval = (sdkp->media_present != sdkp->previous_state || - (sdkp->media_present && sdp->changed)); - if (retval) + if (sdp->changed) sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL); - sdkp->previous_state = sdkp->media_present; - - /* sdp->changed indicates medium was changed or is not present */ - sdp->changed = !sdkp->media_present; kfree(sshdr); + + retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0; + sdp->changed = 0; return retval; } @@ -1169,7 +1187,7 @@ static const struct block_device_operations sd_fops = { #ifdef CONFIG_COMPAT .compat_ioctl = sd_compat_ioctl, #endif - .media_changed = sd_media_changed, + .check_events = sd_check_events, .revalidate_disk = sd_revalidate_disk, .unlock_native_capacity = sd_unlock_native_capacity, }; @@ -1312,23 +1330,6 @@ static int sd_done(struct scsi_cmnd *SCpnt) return good_bytes; } -static int media_not_present(struct scsi_disk *sdkp, - struct scsi_sense_hdr *sshdr) -{ - - if (!scsi_sense_valid(sshdr)) - return 0; - /* not invoked for commands that could return deferred errors */ - if (sshdr->sense_key != NOT_READY && - sshdr->sense_key != UNIT_ATTENTION) - return 0; - if (sshdr->asc != 0x3A) /* medium not present */ - return 0; - - set_media_not_present(sdkp); - return 1; -} - /* * spinup disk - called only in sd_revalidate_disk() */ @@ -1503,7 +1504,7 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp, */ if (sdp->removable && sense_valid && sshdr->sense_key == NOT_READY) - sdp->changed = 1; + set_media_not_present(sdkp); /* * We used to set media_present to 0 here to indicate no media @@ -2389,8 +2390,10 @@ static void sd_probe_async(void *data, async_cookie_t cookie) gd->driverfs_dev = &sdp->sdev_gendev; gd->flags = GENHD_FL_EXT_DEVT; - if (sdp->removable) + if (sdp->removable) { gd->flags |= GENHD_FL_REMOVABLE; + gd->events |= DISK_EVENT_MEDIA_CHANGE; + } add_disk(gd); sd_dif_config_host(sdkp); @@ -2472,7 +2475,6 @@ static int sd_probe(struct device *dev) sdkp->disk = gd; sdkp->index = index; atomic_set(&sdkp->openers, 0); - sdkp->previous_state = 1; if (!sdp->request_queue->rq_timeout) { if (sdp->type != TYPE_MOD) diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h index 55488faf0815..c9d8f6ca49e2 100644 --- a/drivers/scsi/sd.h +++ b/drivers/scsi/sd.h @@ -55,7 +55,6 @@ struct scsi_disk { u8 media_present; u8 write_prot; u8 protection_type;/* Data Integrity Field */ - unsigned previous_state : 1; unsigned ATO : 1; /* state of disk ATO bit */ unsigned WCE : 1; /* state of disk WCE bit */ unsigned RCD : 1; /* state of disk RCD bit, unused */