So do GEOM. Not a pretty sight.
Take all the interesting stuff out of GEOM::disk_create(), and leave just
the creation of the fake dev_t. Schedule the topology munging to happen
in the g_event thread with g_call_me().
This makes disk_create() pretty lock-agnostic, almost lock-atheist.
Tripped over by: peter
Sponsored by: DARPA & NAI Labs
and therefore we need a way for ioctl handlers to run in that thread
in GEOM. Rather than invent a complicated registration system to
recognize which ioctl handler to use for a given ioctl, we still
schedule all ioctls down the tree as bio transactions but add a
special return code that means "call me directly" and have the
geom_dev layer do that.
Use this for all ioctls that make it as far as a diskdriver to
avoid any backwards compatibility problems.
Requested by: scottl
Sponsored by: DARPA & NAI Labs
NB: But it will enable it in all kernels not having options "NO_GEOM"
Put the GEOM related options into the intended order.
Add "options NO_GEOM" to all kernel configs apart from NOTES.
In some order of controlled fashion, the NO_GEOM options will be
removed, architecture by architecture in the coming days.
There are currently three known issues which may force people to
need the NO_GEOM option:
boot0cfg/fdisk:
Tries to update the MBR while it is being used to control
slices. GEOM does not allow this as a direct operation.
SCSI floppy drives:
Appearantly the scsi-da driver return "EBUSY" if no media
is inserted. This is wrong, it should return ENXIO.
PC98:
It is unclear if GEOM correctly recognizes all variants of
PC98 disklabels. (Help Wanted! I have neither docs nor HW)
These issues are all being worked.
Sponsored by: DARPA & NAI Labs.
that this will make people use this for their future copy&paste operations.
Rework the detection of raw-disk offsets in disklabels. This actually
unearthed a number of bugs in the (now) previous version.
Also accept labels which don't have a magic RAW_PART, provided they don't
confuse us too much.
Change the order of our sanity-checks on labels found on disks to be more
robust.
Check against MAXPARTITIONS in our sanity-check and reject disklabels
we cannot cope with.
Create new g_bsd_modify() function to implment disklabel modifying
ioctls.
Implement DIOCSDINFO and DIOCWDINFO with the provision that the latter
still not writes your change back to disk. I didn't have the nerves
for that yet.
In the start routine, use g_call_me() for complex ioctls to prevent
sleeping.
Sponsored by: DARPA & NAI Labs.
with support for trying, doing and forcing.
This will eventually replace g_slice_addslice() which gets changed from
grabbing topology to requing it in this commit as well.
Sponsored by: DARPA & NAI Labs.
work.
This prevents people from sleeping in the UP/DOWN I/O path by mistake
or design (doing so almost invariably result in deadlocks since it
stalls all I/O processing in the given direction.
Sponsored by: DARPA & NAI Labs.
a disklabel modification tries to change an open device, and no
counter-examples exists.
Be less facist about when we can do Setattr, the openmodes of devices
are so loosely managed that the "exclusive" count is almost useless.
Sponsored by: DARPA & NAI Labs.
Add a __unused.
Make the 2byte decoder functions return 16 bits for the benefits
of picky lints.
No need to grab giant around a tsleep() when we have a timeout.
Sponsored by: DARPA & NAI Labs.
to be performed in the event-thread.
To do this, we need to lock the eventlist with g_eventlock (nee g_doorlock),
since g_call_me() being called from the UP/DOWN paths will not be able to
aquire g_topology_lock.
This also means that for now these events are not referenced on any
particular consumer/provider/geom.
For UP/DOWN path use, this will not become a problem since the access()
function will make sure we drain any bio's before we dismantle.
Sponsored by: DARPA & NAI Labs.
and predictable way, and I apologize if I have gotten it wrong anywhere,
getting prior review on a patch like this is not feasible, considering
the number of people involved and hardware availability etc.)
If struct disklabel is the messenger: kill the messenger.
Inside struct disk we had a struct disklabel which disk drivers used to
communicate certain metrics to the disklayer above (GEOM or the disk
mini-layer). This commit changes this communication to use four
explicit fields instead.
Amongst the benefits is that the fields do not get overwritten by
wrong or bogus on-disk disklabels.
Once that is clear, <sys/disk.h> which is included in the drivers
no longer need to pull <sys/disklabel.h> and <sys/diskslice.h> in,
the few places that needs them, have gotten explicit #includes for
them.
The disklabel inside struct disk is now only for internal use in
the disk mini-layer, so instead of embedding it, we malloc it as
we need it.
This concludes (modulus any mistakes) the series of disklabel related
commits.
I belive it all amounts to a NOP for all the rest of you :-)
Sponsored by: DARPA & NAI Labs.
