We may actually be increasing Giant contention doing so because the
actual stuff we do is very cheap.
Also I am not convinced there is not a tiny window for a race here.
Change the si_name of dev_t's to be a char * and put a private buffer for
holding the name at then end of the struct.
Initialize si_name to point to the private buffer.
Put a KASSERT in geom_disk to prevent overrun on the fake dev_t we still
have to generate for the disk_drivers.
this will cause volume labels to be exposed in /dev/vol/<volname>. Currently,
there is no conflict resolution if more than one FS has the same volume name.
Reviewed by: phk
Make passing the methods in a cdevsw structure optional.
Move "CANFREE" and "NOGIANT" flags into struct disk instead of the
cdevsw which may or may not be there.
Rename CANFREE to CANDELETE to match BIO_DELETE operation.
Add "OPEN" flag so drivers don't have to provide open/close methods
just to maintain such a flag.
Add temporary stopgap include of <sys/conf.h> to <sys/disk.h> until
the files which have them in the other order are fixed.
Add KASSERTS to make sure we don't get fed too many NULL pointers.
Clear our geom's softc pointer before we wither.
labeled disk.
This is complicated by the fact that BBSIZE is greater than the
PAGE_SIZE limit ioctl inflicts on arguments which are automatically
copied in.
As long as we don't need access to userland memory (copyin/out) we
can deal with the ioctl using g_callme() which executes it from the
GEOM event thread.
Once we need copyin/out, we need to return the bio with EDIRIOCTL
in order to make geom_dev call us back in the original process context
where copyin will work.
Unfortunately, that results in us getting called with Giant, so
we have to DROP_GIANT/PICKUP_GIANT around the code where we diddle
GEOMs internals.
Sometimes you just can't win...
... But it does make geom_bsd.c an almost complete example of the
GEOM beastiarium.
CAUTION:
Previously CCD would be different from all other disks in
the system in that there were no "ccd0" device, only a
"ccd0c" device.
This is no longer so after this commit. If you access a
ccd device through the "/dev/ccd0c" device _and_ have not
actually put a BSD disklabel on the device, you will have
to use the name "/dev/ccd0". If your CCD device contains
a BSD disklabel there should be no difference.
You need to recompile ccdconfig(8) using the changed
src/sys/sys/ccdvar.h for the -g "show me" option to work.
I have run the regression test I created before I started
overhauling CCD and it flags no problems, but this code
is mildly evil, so take care. If you would cry if you lost
what's on CCD, make a back before you upgrade.
Create separate cdevsw for the /dev/ccd.ctl device.
Remove the cloning function, the disk-minilayer will do all naming
for us.
Remove the ccdunit and ccdpart functions and carry the softc pointer
in the relevant dev_t's and structures.
Release all memory when a CCD device is unconfigured, previously
the softc would linger behind.
Remove all traces of BSD disklabel fiddling code.
Remove ccdpsize, the disk mini-layer does this for us.
Don't allocate memory with M_WAITOK in ccdstrategy().
Remove boundary checks which the disk mini-layer does for us.
Don't allocate space for more than 2 ccdbuf, RAID was never implemented.
NB: I have not tried to address any of the preexisting ailments of CCD.
and can be added back selectively, should anybody start to interest
themselves for the internal workings of ccd.
This commit will make the diffs for the following commits much more
readable.
the three configuration ioctls which need a unit number.
Add a "ccd.ctl" device for config operations.
Implement ioctls on ccd.ctl which rely on the explicityly passed
unit numbers.
Update ccdconfig to use the new ccd.ctl interface.
Add code to the kernel to detect old ccdconfig binaries, and whine
about it.
Add code to ccdconfig to detect old kernels, and whine about it.
These two compatibility measures will be retained only for a limited
period since they are in the way of GEOM'ification of ccd.
ioctls are no reliable indication of the ioctls "set" or "get" nature or if
such simplistic categories can even be applied.
MFC candidate: boot0cfg issue.
some trick is necessary to prevent further BSD geoms from attaching to
that. Our old trick was to make sure we don't attach to a geom from
the "BSD" class, but this doesn't work if an intermediary geom obscures
this fact. Instead, calculate the MD5 checksum of the label we target
and ask if anybody below us loves that label. If they do we don't.
Coded by: gordon.
