(I did this because the system could panic otherwise. But this seemed to
be a side-effect of another mistake that was present in the code before it
was commited. So effectively this simplification should have happened
before.)
if not, fallback to VOP_READ and VOP_WRITE. This makes vnd work with files
on, e.g. tmpfs and smbfs; all file systems should behave as before.
OK'ed by silence in tech-kern@.
From various discussion about vndstrategy (see
http://mail-index.netbsd.org/tech-kern/2005/03/29/0034.htmlhttp://mail-index.netbsd.org/tech-kern/2005/03/23/0015.html)
it's not correct to tsleep() in a strategy routine, which may be called from
interrupt context.
Unfortunably this reopens PR/10731, PR/12189, PR/20296, PR/34293
As for what the correct fix it, this needs to be analysed deeper. I suspect
throttling the caller in vnd only hides the problem; the same caller writing
to some other device could exaust all buffers as well. If this driver doesn't
need to allocate buffer this won't cause a deadlock, but it's bad for
performances on systems with e.g. multiple drives. Also, others stacked
block device drivers may also have this issue.
spurious messages when doing "vnconfig -l", but it also means there won't
be a message when an actual device is created. Oh, well.
PR#33116 by Izumi Tsutsui.
- use vmspace rather than proc or lwp where appropriate.
the latter is more natural to specify an address space.
(and less likely to be abused for random purposes.)
- fix a swdmover race.
for "strange" filesystems like nfs. PR/32671 from Simon Burge.
although i'm not really happy with this "fix", i think that the code will
be replaced with direct i/o anyway, sooner or later...
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)
-fabricate a trivial geometry also in the case of images <=1M
(XXX I didn't add a check for >0 size -- this is generally harmless
because there are enough boundary checks present, and it allows
to test some corner cases in the disklabel handling code)
-ignore the VNF_KLABEL flag -- the vnd device is if limited (and
well-defined!) lifetime anyway, and the implications of "keeplabel"
are confusing at best
allows the strategy routine to be called from interrupt context, fixes
PR kern/29775 by Juan RP.
Now that pool_get() is only called from thread context, change PR_NOWAIT to
PR_WAITOK. Fix PR kern/26272 by Juergen Hannken-Illjes.
OK'd by thorpej@
christos