This is necessary for two reasons:
1) In order to avoid collisions with the use of a BIOs flags set by a consumer
or a provider
2) Because GV_BIO_DONE was used to mark a BIO as done, not enough flags was
available, so the consumer flags of a BIO had to be misused in order to
support enough flags. The new queue makes it possible to recycle the
GV_BIO_DONE flag into GV_BIO_GROW.
As a consequence, gvinum will now work with any other GEOM class under it or
on top of it.
- Use bio_pflags for storing internal flags on downgoing BIOs, as the requests
appear to come from a consumer of a gvinum volume. Use bio_cflags only for
cloned BIOs.
- Move gv_post_bio to be used internally for maintenance requests.
- Remove some cases where flags where set without need.
PR: kern/133604
as they do not really relate and to prepare for an additional queue to be
covered by the BIO queue mutex.
- Implement wrappers for fetching the next element from the event queue as well
as for putting a new element into the BIO queue.
as the renaming only changes internal gvinum names and will not alter the geom
topology.
- The topology lock was not held when calling g_wither_geom after renaming.
naming of the partitions (GEOM_PART_EBR_COMPAT). When
compatibility is enabled, changes to the partitioning are
disallowed.
Remove the device name aliasing added previously to provide
backward compatibility, but which in practice doesn't give
us anything.
Enable compatibility on amd64 and i386.
o PC98 uses 32-bit block numbers. Limit the scheme to 2^32-1
blocks when the media is larger. The 32-bit block numbers
are implicit (16-bit cylinder * 8-bit head * 8-bit sector).
o EBR uses 32-bit block numbers. Limit the scheme to 2^32-1
blocks when the media is larger.
o Calculate the number of entries based on the rounded media
size, rather than the raw media size.
The work have been under testing and fixing since then, and it is mature enough
to be put into HEAD for further testing.
A lot have changed in this time, and here are the most important:
- Gvinum now uses one single workerthread instead of one thread for each
volume and each plex. The reason for this is that the previous scheme was
very complex, and was the cause of many of the bugs discovered in gvinum.
Instead, gvinum now uses one worker thread with an event queue, quite
similar to what used in gmirror.
- The rebuild/grow/initialize/parity check routines no longer runs in
separate threads, but are run as regular I/O requests with special flags.
This made it easier to support mounted growing and parity rebuild.
- Support for growing striped and raid5-plexes, meaning that one can extend the
volumes for these plex types in addition to the concat type. Also works while
the volume is mounted.
- Implementation of many of the missing commands from the old vinum:
attach/detach, start (was partially implemented), stop (was partially
implemented), concat, mirror, stripe, raid5 (shortcuts for creating volumes
with one plex of these organizations).
- The parity check and rebuild no longer goes between userland/kernel, meaning
that the gvinum command will not stay and wait forever for the rebuild to
finish. You can instead watch the status with the list command.
- Many problems with gvinum have been reported since 5.x, and some has been hard
to fix due to the complicated architecture. Hopefully, it should be more
stable and better handle edge cases that previously made gvinum crash.
- Failed drives no longer disappears entirely, but now leave behind a dummy
drive that makes sure the original state is not forgotten in case the system
is rebooted between drive failures/swaps.
- Update manpage to reflect new commands and extend it with some examples.
Sponsored by: Google Summer of Code 2007
Mentored by: le
Tested by: Rick C. Petty <rick-freebsd2008 -at- kiwi-computer.com>
o Don't create an APM scheme underneath another scheme when
the probe doesn't allow it.
o APM uses 32-bit block numbers. Limit the scheme to 2^32-1
blocks when the media is larger.
"raw" names. While there, change the formatting of extended MSDOS partitions
so that the dot (".") is not used to separate two numbers (which kind of
looks like the whole is a decimal number). Use "+" instead, which also
hints that the second part of the name is the offset from the start of
the partition in the first part of the name. Also change the offset from
decimal to hexadecimal notation, simply for aesthetic reasons and future
compatibility.
GEOM_PART is the default in 8-CURRENT but not yet in 7-STABLE so this
changeset can be MFC-ed without causing major problems from the second
part.
Reviewed by: marcel
Approved by: gnn (mentor)
MFC after: 2 weeks
to resurrect (maybe honor foot shooting bit in kern.geom_debugflags)
o fix match macro so we now recognize we want to merge FIS dir with RedBoot
config parameters even if we don't actually do it
properly. Otherwise the minimum of 1 is used and you can
only insert a single partition/slice and only at sector
0 (index 1).
o When adding a partition/slice, recalculate the index after
the start and size of the partition/slice are adjusted to
make them a multiple of the track size. Since the precheck
method sets the index based on the start of the partition
as provided by the user, we know that we're off by at most
1 and adjusting the index is safe.
1. Extend geom_dev by having it create the symlink (i.e. call
make_dev_alias) based on the DIOCGPROVIDERALIAS ioctl.
In this way the functionaility is generic and thus usable
by any geom/provider.
2. Have g_part handle said ioctl through the devalias method,
so that it's under control of the scheme itself. By design
the alias will not be created for newly added partitions.
method allows schemes to reject the ctl request, pre-check
the parameters and/or modify/set parameters. There are 2
use cases that triggered the addition:
1. When implementing a R/O scheme, deletes will still
happen to the in-memory representation. The scheme is
not involved in that operation. The pre-check method
can be used to fail the delete up-front. Without this
the write to disk will typically fail, but at that
time the delete already happened.
2. The EBR scheme uses a linked list to record slices.
There's no index. The EBR scheme defines the index
as a function of the start LBA of the partition. The
add verb picks an index for the range and then invokes
the add method of the scheme to fill in the blanks. It
is too late for the add method to change the index.
The pre-check is used to set the index up-front. This
also (silently) overrides/nullifies any (pointless)
user-specified index value.
found inside extended partitions and used to create logical partitions.
At this time write/modify support is not (yet) present.
The EBR and MBR schemes both check the parent scheme. The MBR will
back-off when nested under another MBR, whereas the EBR only nests
under a MBR.
underlying partitioning scheme.
o Put the start and end of the partition in the XML configuration.
The start and end are the LBAs of the first and last sector
(resp.) of the partition. They are currently identical to the
offset and size attributes, which describe the partition as an
offset and size in bytes, but may not in the future. The start
and end will be used for the logical partition boundaries and
may include metadata. The offset and size will always represent
the useful storage space within the partition. Typically these
two notions are the same, but for logical partitions in an
extended partition, the EBR is more naturally treated as being
part of the partition.
