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author | Jeff Garzik <jeff@garzik.org> | 2007-10-29 21:15:22 (GMT) |
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committer | Jeff Garzik <jeff@garzik.org> | 2007-11-04 02:23:02 (GMT) |
commit | a341cd0f6a0fde1f85fec9aa8f81f824ea4a3f92 (patch) | |
tree | e96b2ab04c94cb1a29d972b135dd6b2bdfac0f78 /drivers/scsi/scsi_lib.c | |
parent | b4f555081fdd27d13e6ff39d455d5aefae9d2c0c (diff) | |
download | linux-a341cd0f6a0fde1f85fec9aa8f81f824ea4a3f92.tar.xz |
SCSI: add asynchronous event notification API
Originally based on a patch by Kristen Carlson Accardi @ Intel.
Copious input from James Bottomley.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 88de771..0e81e4c 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2115,6 +2115,142 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) EXPORT_SYMBOL(scsi_device_set_state); /** + * sdev_evt_emit - emit a single SCSI device uevent + * @sdev: associated SCSI device + * @evt: event to emit + * + * Send a single uevent (scsi_event) to the associated scsi_device. + */ +static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) +{ + int idx = 0; + char *envp[3]; + + switch (evt->evt_type) { + case SDEV_EVT_MEDIA_CHANGE: + envp[idx++] = "SDEV_MEDIA_CHANGE=1"; + break; + + default: + /* do nothing */ + break; + } + + envp[idx++] = NULL; + + kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); +} + +/** + * sdev_evt_thread - send a uevent for each scsi event + * @work: work struct for scsi_device + * + * Dispatch queued events to their associated scsi_device kobjects + * as uevents. + */ +void scsi_evt_thread(struct work_struct *work) +{ + struct scsi_device *sdev; + LIST_HEAD(event_list); + + sdev = container_of(work, struct scsi_device, event_work); + + while (1) { + struct scsi_event *evt; + struct list_head *this, *tmp; + unsigned long flags; + + spin_lock_irqsave(&sdev->list_lock, flags); + list_splice_init(&sdev->event_list, &event_list); + spin_unlock_irqrestore(&sdev->list_lock, flags); + + if (list_empty(&event_list)) + break; + + list_for_each_safe(this, tmp, &event_list) { + evt = list_entry(this, struct scsi_event, node); + list_del(&evt->node); + scsi_evt_emit(sdev, evt); + kfree(evt); + } + } +} + +/** + * sdev_evt_send - send asserted event to uevent thread + * @sdev: scsi_device event occurred on + * @evt: event to send + * + * Assert scsi device event asynchronously. + */ +void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) +{ + unsigned long flags; + + if (!test_bit(evt->evt_type, sdev->supported_events)) { + kfree(evt); + return; + } + + spin_lock_irqsave(&sdev->list_lock, flags); + list_add_tail(&evt->node, &sdev->event_list); + schedule_work(&sdev->event_work); + spin_unlock_irqrestore(&sdev->list_lock, flags); +} +EXPORT_SYMBOL_GPL(sdev_evt_send); + +/** + * sdev_evt_alloc - allocate a new scsi event + * @evt_type: type of event to allocate + * @gfpflags: GFP flags for allocation + * + * Allocates and returns a new scsi_event. + */ +struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, + gfp_t gfpflags) +{ + struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); + if (!evt) + return NULL; + + evt->evt_type = evt_type; + INIT_LIST_HEAD(&evt->node); + + /* evt_type-specific initialization, if any */ + switch (evt_type) { + case SDEV_EVT_MEDIA_CHANGE: + default: + /* do nothing */ + break; + } + + return evt; +} +EXPORT_SYMBOL_GPL(sdev_evt_alloc); + +/** + * sdev_evt_send_simple - send asserted event to uevent thread + * @sdev: scsi_device event occurred on + * @evt_type: type of event to send + * @gfpflags: GFP flags for allocation + * + * Assert scsi device event asynchronously, given an event type. + */ +void sdev_evt_send_simple(struct scsi_device *sdev, + enum scsi_device_event evt_type, gfp_t gfpflags) +{ + struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); + if (!evt) { + sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", + evt_type); + return; + } + + sdev_evt_send(sdev, evt); +} +EXPORT_SYMBOL_GPL(sdev_evt_send_simple); + +/** * scsi_device_quiesce - Block user issued commands. * @sdev: scsi device to quiesce. * |