diff options
| author | James Bottomley <James.Bottomley@steeleye.com> | 2005-08-05 21:45:40 -0500 |
|---|---|---|
| committer | James Bottomley <jejb@mulgrave.(none)> | 2005-08-08 09:55:39 -0500 |
| commit | b21a41385118f9a6af3cd96ce71090c5ada52eb5 (patch) | |
| tree | 4eb9124ae72e1a905094c259465718793698e603 /drivers/scsi/scsi.c | |
| parent | f03a567054fea4f9d43c50ec91338266c0bd588d (diff) | |
[SCSI] add global timeout to the scsi mid-layer
There are certain rogue devices (and the aic7xxx driver) that return
BUSY or QUEUE_FULL forever. This code will apply a global timeout (of
the total number of retries times the per command timer) to a given
command. If it is exceeded, the command is completed regardless of its
state.
The patch also removes the unused field in the command: timeout and
timeout_total.
This solves the problem of detecting an endless loop in the mid-layer
because of BUSY/QUEUE_FULL bouncing, but will not recover the device.
In the aic7xxx case, the driver can be recovered by sending a bus reset,
so possibly this should be tied into the error handler?
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/scsi.c')
| -rw-r--r-- | drivers/scsi/scsi.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index d1aa95d45a7..4befbc275f9 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -268,6 +268,7 @@ struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, int gfp_mask) } else put_device(&dev->sdev_gendev); + cmd->jiffies_at_alloc = jiffies; return cmd; } EXPORT_SYMBOL(scsi_get_command); @@ -798,9 +799,23 @@ static void scsi_softirq(struct softirq_action *h) while (!list_empty(&local_q)) { struct scsi_cmnd *cmd = list_entry(local_q.next, struct scsi_cmnd, eh_entry); + /* The longest time any command should be outstanding is the + * per command timeout multiplied by the number of retries. + * + * For a typical command, this is 2.5 minutes */ + unsigned long wait_for + = cmd->allowed * cmd->timeout_per_command; list_del_init(&cmd->eh_entry); disposition = scsi_decide_disposition(cmd); + if (disposition != SUCCESS && + time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { + dev_printk(KERN_ERR, &cmd->device->sdev_gendev, + "timing out command, waited %ds\n", + wait_for/HZ); + disposition = SUCCESS; + } + scsi_log_completion(cmd, disposition); switch (disposition) { case SUCCESS: |