Re: [linux-usb-devel] oops on usb storage device disconnect with 2.6.14-rc1

James Bottomley
2005-09-18T20:05:29Z

On Sat, 2005-09-17 at 19:35 -0500, James Bottomley wrote:
> The attached should be that patch with the race window closed.

There's a big oops in this one (and there was when greg tested it). The
state checker is reversed (it's checking !scsi_host_set_state() for
indicating a problem ... of course, the return is 0 on success or
error). I've corrected this; Greg, could you retest?

Thanks,

James

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -98,6 +98,7 @@ int scsi_host_set_state(struct Scsi_Host
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
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);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -1265,9 +1265,8 @@ int scsi_device_cancel(struct scsi_devic
list_for_each_safe(lh, lh_sf, &active_list) {
scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
list_del_init(lh);
- if (recovery) {
- scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD);
- } else {
+ if (recovery &&
+ !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)) {
scmd->result = (DID_ABORT << 16);
scsi_finish_command(scmd);
}
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -68,19 +68,24 @@ int scsi_eh_scmd_add(struct scsi_cmnd *s
{
struct Scsi_Host *shost = scmd->device->host;
unsigned long flags;
+ int ret = 0;

if (shost->eh_wait == NULL)
return 0;

spin_lock_irqsave(shost->host_lock, flags);
+ if (scsi_host_set_state(shost, SHOST_RECOVERY))
+ if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
+ goto out_unlock;

+ ret = 1;
scmd->eh_eflags |= eh_flag;
list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
- scsi_host_set_state(shost, SHOST_RECOVERY);
shost->host_failed++;
scsi_eh_wakeup(shost);
+ out_unlock:
spin_unlock_irqrestore(shost->host_lock, flags);
- return 1;
+ return ret;
}

/**
@@ -176,8 +181,8 @@ void scsi_times_out(struct scsi_cmnd *sc
}

if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
- panic("Error handler thread not present at %p %p %s %d",
- scmd, scmd->device->host, __FILE__, __LINE__);
+ scmd->result |= DID_TIME_OUT << 16;
+ __scsi_done(scmd);
}
}

@@ -196,8 +201,7 @@ int scsi_block_when_processing_errors(st
{
int online;

- wait_event(sdev->host->host_wait, (sdev->host->shost_state !=
- SHOST_RECOVERY));
+ wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));

online = scsi_device_online(sdev);

@@ -1441,6 +1445,7 @@ static void scsi_eh_lock_door(struct scs
static void scsi_restart_operations(struct Scsi_Host *shost)
{
struct scsi_device *sdev;
+ unsigned long flags;

/*
* If the door was locked, we need to insert a door lock request
@@ -1460,7 +1465,11 @@ static void scsi_restart_operations(stru
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
__FUNCTION__));

- scsi_host_set_state(shost, SHOST_RUNNING);
+ spin_lock_irqsave(shost->host_lock, flags);
+ if (scsi_host_set_state(shost, SHOST_RUNNING))
+ if (scsi_host_set_state(shost, SHOST_CANCEL))
+ BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
+ spin_unlock_irqrestore(shost->host_lock, flags);

wake_up(&shost->host_wait);

diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
--- a/drivers/scsi/scsi_ioctl.c
+++ b/drivers/scsi/scsi_ioctl.c
@@ -458,7 +458,7 @@ int scsi_nonblockable_ioctl(struct scsi_
* error processing, as long as the device was opened
* non-blocking */
if (filp && filp->f_flags & O_NONBLOCK) {
- if (sdev->host->shost_state == SHOST_RECOVERY)
+ if (scsi_host_in_recovery(sdev->host))
return -ENODEV;
} else if (!scsi_block_when_processing_errors(sdev))
return -ENODEV;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -447,7 +447,7 @@ void scsi_device_unbusy(struct scsi_devi

spin_lock_irqsave(shost->host_lock, flags);
shost->host_busy--;
- if (unlikely((shost->shost_state == SHOST_RECOVERY) &&
+ if (unlikely(scsi_host_in_recovery(shost) &&
shost->host_failed))
scsi_eh_wakeup(shost);
spin_unlock(shost->host_lock);
@@ -1339,7 +1339,7 @@ static inline int scsi_host_queue_ready(
struct Scsi_Host *shost,
struct scsi_device *sdev)
{
- if (shost->shost_state == SHOST_RECOVERY)
+ if (scsi_host_in_recovery(shost))
return 0;
if (shost->host_busy == 0 && shost->host_blocked) {
/*
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -57,6 +57,8 @@ static struct {
{ SHOST_CANCEL, "cancel" },
{ SHOST_DEL, "deleted" },
{ SHOST_RECOVERY, "recovery" },
+ { SHOST_CANCEL_RECOVERY, "cancel/recovery" },
+ { SHOST_DEL_RECOVERY, "deleted/recovery", },
};
const char *scsi_host_state_name(enum scsi_host_state state)
{
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1027,7 +1027,7 @@ sg_ioctl(struct inode *inode, struct fil
if (sdp->detached)
return -ENODEV;
if (filp->f_flags & O_NONBLOCK) {
- if (sdp->device->host->shost_state == SHOST_RECOVERY)
+ if (scsi_host_in_recovery(sdp->device->host))
return -EBUSY;
} else if (!scsi_block_when_processing_errors(sdp->device))
return -EBUSY;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -439,6 +439,8 @@ enum scsi_host_state {
SHOST_CANCEL,
SHOST_DEL,
SHOST_RECOVERY,
+ SHOST_CANCEL_RECOVERY,
+ SHOST_DEL_RECOVERY,
};

struct Scsi_Host {
@@ -621,6 +623,13 @@ static inline struct Scsi_Host *dev_to_s
return container_of(dev, struct Scsi_Host, shost_gendev);
}

+static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
+{
+ return shost->shost_state == SHOST_RECOVERY ||
+ shost->shost_state == SHOST_CANCEL_RECOVERY ||
+ shost->shost_state == SHOST_DEL_RECOVERY;
+}
+
extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
extern void scsi_flush_work(struct Scsi_Host *);