On 24 Jan 2000, david parsons wrote:
> root@downbelow# ls -l /dev/sdq
> ls: /dev/sdq: No such file or directory
> root@downbelow# ls -l /dev/sdq*
> ls: /dev/sdq*: No such file or directory
> root@downbelow#
>
> I presume that /dev/sdq will be living on Yet Another major to get
> around the bizarre type-of-device numbering of scsi devices? I'll
> just start shuddering now and avoid the rush.
Already does. See Documentation/devices.txt for gory details.
> >> >This change is needed if we want to avoid (a) races and (b) major suckage
> >> >with exporting spinlocks, etc.
> >>
> >> Why?
> >
> >One word: rmmod.
>
> So the output of /proc/devices will be out of date if an rmmod is done
> just after the code trawls over the registry entry for the offending
> device. Is this important?
Umm... Not really. There is a bunch of nastier races around the whole
thing (and insmod sucks too - figuring out results of the following
open /dev/foo
request_module
module_init
register_blkdev
pointer to methods table set
initializing disk/controller
open /dev/foo
found the pointer
success
read from the thing
woops!
finish initialization... too late ;-<
is not too hard). So that stuff _really_ needs fixing - the races are
pretty real and lead to Bad Things(tm). Moreover, methods should not live
on per-major level. I have a fix (testing the sucker right now), but it
changes quite a bit of block_dev.c and kills the array of pairs
name/methods...
> >Umm... Will /proc/drivers/block/<driver>/ranges make you happy? I.e.
> >$ cat /proc/drivers/block/ide/ranges
> >0300(80)
> >1600(80)
> >2100(80)
> >2200(80)
> >$ cat /proc/drivers/block/ide/hdb/range
> >0340(40)
>
> No. That's a pretty awful scheme there.
>
> ____
> david parsons \bi/ so now I need to make a zillion system calls to figure
> \/ out which major is affiliated with which hdx device?
Arrgh. Could we please forget about major:minor split?
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This archive was generated by hypermail 2b29 : Mon Jan 31 2000 - 21:00:12 EST