Re: PATCH: (as33) Remove /proc/scsi directory in scsi_remove_host()

[Mike Anderson <andmike@us.ibm.com>]

Christoph Hellwig [hch@infradead.org] wrote:
> On Wed, Jun 11, 2003 at 11:23:24AM -0700, Mike Anderson wrote:
> > Alan,
> > 	This is bug, but I do not think this fix will work for non
> > 	legacy callers. LLDDs that just use scsi_add_host and
> > 	scsi_remove_host would have the remove_proc_entry called
> > 	possibly too early.
> 
> Why should we care when the proc entry is remove?  The whole ->proc_info
> mess is marked obsolete in 2.5 so no one should rely on it.  It's certainly
> better than leaking the proc_dir_entry :)

While it is marked obsolete, but it should still function shouldn't it? 
Even if we use the proc_info replacement you suggested in previous mail:
http://marc.theaimsgroup.com/?l=linux-scsi&m=105112638920306&w=2
we should have a similar cleanup issue.

The patch suggested gives the output shown below which leaves "n" number of file
entries not accessible.

Ex.
# ls /proc/scsi/scsi_debug/
1  2  3
# echo "-1" > add_host
Synchronizing SCSI cache: 
# ls /proc/scsi
device_info  ips  scsi  sg

This proc cleanup routine also races with the read / write routines that
previously where "protected" by the procfs try_module_get. 

I was looking into closing this race, but if you feel it is not
worthwhile I can go look at other issues we have.

-andmike
--
Michael Anderson
andmike@us.ibm.com