From 939647ee308e0ad924e776657704c7bedd498664 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Sun, 18 Sep 2005 15:05:20 -0500 Subject: [SCSI] fix oops on usb storage device disconnect We fix the oops by enforcing the host state model. There have also been two extra states added: SHOST_CANCEL_RECOVERY and SHOST_DEL_RECOVERY so we can take the model through host removal while the recovery thread is active. Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 85503fad789..f2a72d33132 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -98,6 +98,7 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) switch (oldstate) { case SHOST_CREATED: case SHOST_RUNNING: + case SHOST_CANCEL_RECOVERY: break; default: goto illegal; @@ -107,12 +108,31 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) case SHOST_DEL: switch (oldstate) { case SHOST_CANCEL: + case SHOST_DEL_RECOVERY: break; default: goto illegal; } break; + case SHOST_CANCEL_RECOVERY: + switch (oldstate) { + case SHOST_CANCEL: + case SHOST_RECOVERY: + break; + default: + goto illegal; + } + break; + + case SHOST_DEL_RECOVERY: + switch (oldstate) { + case SHOST_CANCEL_RECOVERY: + break; + default: + goto illegal; + } + break; } shost->shost_state = state; return 0; @@ -134,13 +154,24 @@ EXPORT_SYMBOL(scsi_host_set_state); **/ void scsi_remove_host(struct Scsi_Host *shost) { + unsigned long flags; down(&shost->scan_mutex); - scsi_host_set_state(shost, SHOST_CANCEL); + spin_lock_irqsave(shost->host_lock, flags); + if (scsi_host_set_state(shost, SHOST_CANCEL)) + if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { + spin_unlock_irqrestore(shost->host_lock, flags); + up(&shost->scan_mutex); + return; + } + spin_unlock_irqrestore(shost->host_lock, flags); up(&shost->scan_mutex); scsi_forget_host(shost); scsi_proc_host_rm(shost); - scsi_host_set_state(shost, SHOST_DEL); + spin_lock_irqsave(shost->host_lock, flags); + if (scsi_host_set_state(shost, SHOST_DEL)) + BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); + spin_unlock_irqrestore(shost->host_lock, flags); transport_unregister_device(&shost->shost_gendev); class_device_unregister(&shost->shost_classdev); -- cgit v1.2.3