and bio_inbed fields to 0. Without this change we can end up with
I/O leakage in some rare situations.
I tested this change by putting failure probability mechanism simlar
to this used in NOP class into g_clone_bio(9) function, so it was
able to return NULL with the given probability.
Discussed with: phk
bio_driver1 (as all the rest).
This introduced a small memory leak, but it wasn't really critical,
because maximum memory for g_stripe_zone is always set, so after few
requests gstripe was working in "economic" mode.
It allows to fix problems when last provider's sector is shared between few
providers.
- Bump version number for CONCAT and STRIPE and add code for backward
compatibility.
- Do not bump version number of MIRROR, as it wasn't officially introduced yet.
Even if someone started to play with it, there is no big deal, because
wrong MD5 sum of metadata will deny those providers.
- Update manual pages.
- Add version history to g_(stripe|concat).h files.
understood. This makes room for additional binary compatibility in the
future.
Put fields in the class for the geom's methods and initialize the methods
of a new geom from these fields. This saves some code in all classes.
something goes wrong while running in "fast" mode, we free all bios and
falling back to "economic" mode. Freeing bios, doesn't mean decrease
bio_children, so bio_inbed couldn't be equal to bio_children and request
was never finished.
Decrease bio_children manually when destroying bios.
Reported by: Sam Lawrance <boris@brooknet.com.au>, simon
consumer and 'bio_pflags' which can be used by provider.
- Remove BIO_FLAG1 and BIO_FLAG2 flags. From now on new fields should be
used for internal flags.
- Update g_bio(9) manual page.
- Update some comments.
- Update GEOM_MIRROR, which was the only one using BIO_FLAGs.
Idea from: phk
Reviewed by: phk
set gp->softc to NULL and return ENXIO when it is NULL, so GEOM
will not panic or hang, but unload one device on every 'unload'.
This make 'unload' command usable, but it have to be executed
<number of devices> + 1 times.
- Made use of 'pp' variable.
The different between the new function and g_mirror_orphan() (which was
used previously) is that syncid is bumped immediately, instead of on
first write, because when consumer was spoiled, it means, that its
provider was opened for writing, so we can't trust that its data
will be valid when it will be connected again.
features. The gmirror(8) utility should be used for control of this class.
There is no manual page yet, but I'm working on it with keramida@.
Many useful tests provided by: simon (thank you!)
Some ideas from: scottl, simon, phk
This is really ugly way to do this, but there is no other way for now.
It allows to mount root file system from providers which belong to
those classes.
Approved by: phk
provider.
- Bump version number.
This allows for a quite interesting trick. One can setup a stripe with
stripe size of 512 bytes and create transparent provider on top of it
with sector size equal to <ndisks> * 512. The result will be something
like RAID3 without parity disk (every access will touch all disks).
vinumdrive geom with an exclusive bit. This should fix the problem
when underlying partitions overlap (i.e. the 'a' partition is at
the same offset as the 'c' partition).
Ideas borrowed from pjd@, quite a bit of testing by
Matthias Schuendehuette <msch@snafu.de>.
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
In this mode you can setup even very small stripe size and you can be
sure that only one I/O request will be send to every disks in stripe.
It consumes some more memory, but if allocation fails, it will fall
back to "ECONOMIC" mode.
It is about 10 times faster for small stripe size than "ECONOMIC" mode
and other RAID0 implementations. It is even recommended to use this
mode and small stripe size, so our requests are always splitted.
One can still use "ECONOMIC" mode by setting kern.geom.stripe.fast to 0.
It is also possible to setup maximum memory which "FAST" mode can consume,
by setting kern.geom.stripe.maxmem from /boot/loader.conf.
When we orphan/wither a provider, an attached geom+consumer could
end up being withered as a result and it may be in front of us in
the normal object scanning order so we need to do multi-pass. On
the other hand, there may be withering stuff we can't get rid off
(yet), so we need to keep track of both the existence of withering
stuff and if there is more we can do at this time.
This class is used for detecting volume labels on file systems:
UFS, MSDOSFS (FAT12, FAT16, FAT32) and ISO9660.
It also provide native labelization (there is no need for file system).
g_label_ufs.c is based on geom_vol_ffs from Gordon Tetlow.
g_label_msdos.c and g_label_iso9660.c are probably hacks, I just found
where volume labels are stored and I use those offsets here,
but with this class it should be easy to do it as it should be done by
someone who know how.
Implementing volume labels detection for other file systems also should
be trivial.
New providers are created in those directories:
/dev/ufs/ (UFS1, UFS2)
/dev/msdosfs/ (FAT12, FAT16, FAT32)
/dev/iso9660/ (ISO9660)
/dev/label/ (native labels, configured with glabel(8))
Manual page cleanups and some comments inside were submitted by
Simon L. Nielsen, who was, as always, very helpful. Thanks!
Now, when trying to mount file system in read-only mode it tries to
opened a device for writting to be able to update to read-write mode
latter. Ehh.
Discussed with: phk
to warn about attempts to sleep in the I/O path. This change pushes the
definition and use of 'mymutex' behind #ifdef WITNESS to avoid the cost
in non-debugging cases. This results in a clear .22% performance win for
512 byte and 1k I/O tests on my SMP test box. Not much, but every bit
counts.
not active GEOM providers, it will result in a kernel panic.
If the GEOM provider or disk goes away before the volume
configuration data gets written to the disk, it will result
in another kernel panic.
o Make sure that the drives specified for volume creation
are active GEOM providers.
o When writing out volume configuration data to associated drives,
make sure that the GEOM provider is active, otherwise continue
to the next drive in the volume.
Approved by: le, bmilekic (mentor)
The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()
Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
allocated ressouces should be ultimately freed in gv_destroy_geom()
(when unloading the module and not earlier), but I need to look at this
more closely.
