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.
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.
that a nested partition (typically the BSD disklabel)
is not done tasting while the root file system is being
mounted. While this is rare, it's still possible.
the method for the (indent == NULL) case (i.e. the kern.geom.conftxt
sysctl). The purpose is to extend the conftxt output with scheme-
specific fields which can be used by libdisk. In particular, have
the schemes dump the xs and xt fields, which contain the backward
compatible values for class type and partition type. This allows
libdisk to work with the legacy slicers as well as with gpart and
helps/promotes migration.
to declaring a proper module. The module event handler is part of the
gpart core and will add the scheme to an internal list on module load
and will remove the scheme from the internal list on module unload.
This makes it possible to dynamically load and unload partitioning
schemes.
o Disklabels can have between 8 and 20 partitions (inclusive).
o No device special file is created for the raw partition.
o Switch ia64 to use this backend.
o No support for boot code yet.
on i386 and amd64 machines. The overall process is that /boot/pmbr lives
in the PMBR (similar to /boot/mbr for MBR disks) and is responsible for
locating and loading /boot/gptboot. /boot/gptboot is similar to /boot/boot
except that it groks GPT rather than MBR + bsdlabel. Unlike /boot/boot,
/boot/gptboot lives in its own dedicated GPT partition with a new
"FreeBSD boot" type. This partition does not have a fixed size in that
/boot/pmbr will load the entire partition into the lower 640k. However,
it is limited in that it can only be 545k. That's still a lot better than
the current 7.5k limit for boot2 on MBR. gptboot mostly acts just like
boot2 in that it reads /boot.config and loads up /boot/loader. Some more
details:
- Include uuid_equal() and uuid_is_nil() in libstand.
- Add a new 'boot' command to gpt(8) which makes a GPT disk bootable using
/boot/pmbr and /boot/gptboot. Note that the disk must have some free
space for the boot partition.
- This required exposing the backend of the 'add' function as a
gpt_add_part() function to the rest of gpt(8). 'boot' uses this to
create a boot partition if needed.
- Don't cripple cgbase() in the UFS boot code for /boot/gptboot so that
it can handle a filesystem > 1.5 TB.
- /boot/gptboot has a simple loader (gptldr) that doesn't do any I/O
unlike boot1 since /boot/pmbr loads all of gptboot up front. The
C portion of gptboot (gptboot.c) has been repocopied from boot2.c.
The primary changes are to parse the GPT to find a root filesystem
and to use 64-bit disk addresses. Currently gptboot assumes that the
first UFS partition on the disk is the / filesystem, but this algorithm
will likely be improved in the future.
- Teach the biosdisk driver in /boot/loader to understand GPT tables.
GPT partitions are identified as 'disk0pX:' (e.g. disk0p2:) which is
similar to the /dev names the kernel uses (e.g. /dev/ad0p2).
- Add a new "freebsd-boot" alias to g_part() for the new boot UUID.
MFC after: 1 month
Discussed with: marcel (some things might still change, but am committing
what I have so far)
don't have it. Some partitioning schemes, as well as file systems,
operate on the geometry and without it such schemes (e.g. MBR)
and file systems (e.g. FAT) can't be created. This is useful for
memory disks.
exists and contains the 'C' flag.
o The partition label can be the empty string. It's how labels are
cleared.
o When an action fails, lower permissions when they were raised
in order to allow the action. A failed action will not result
in any uncommitted changes.
o Allow the flags paremeter to be present but empty. It's the
equivalent of not being present.
119373: o Remove the query verb, along with the request and response
parameters.
o Add the version and output parameters.
119390: [APM,GPT] Properly clear deleted entries.
119394: o Make the alias the standard and use the '!' to prefix
literal partition types.
o Treat schemes and partition types as case insensitive.
119462: [GPT] Fix a page fault caused when modifying a partition entry
without a new partition type.
partitioning class that supports multiple schemes. Current
schemes supported are APM (Apple Partition Map) and GPT.
Change all GEOM_APPLE anf GEOM_GPT options into GEOM_PART_APM
and GEOM_PART_GPT (resp).
The ctlreq interface supports verbs to create and destroy
partitioning schemes on a disk; to add, delete and modify
partitions; and to commit or undo changes made.