Re: [PATCH / RFC] scsi_error handler update. (1/4)

[Luben Tuikov <luben@splentec.com>]

James Bottomley wrote:
> 
> I don't like this on several grounds:
> 
> 1. You have a really complex locking hierarchy.  It may be

Several LLDDs may get async event of a target appearing on
the fabric, thus you want to protect the scsi_portal::target_list
with a lock.

Several processes may be initiated who register a scsi_portal
with SCSI Core, thus you want to protect scsi_core::portal_list
with a lock.

The new void scsi_enqueue_cmd(struct scsi_command *) should
be *fully* reentrant, thus you want to protect the
struct scsi_lu::pending_cmd_q with a lock.

... unless you can serialize all those operations elsewhere,
which would be reminicent of the BKL...

-- 
Luben