read requests to its consumer. It has been developed to address
the problem of a horrible read performance of a 64k blocksize FS
residing on a RAID3 array with 8 data components, where a single
disk component would only get 8k read requests, thus effectively
killing disk performance under high load. Documentation will be
provided later. I'd like to thank Vsevolod Lobko for his bright
ideas, and Pawel Jakub Dawidek for helping me fix the nasty bug.
request can still have bio_to set to sc_provider (this is READ part of a
synchronization request) and in this case g_{mirror,raid3}_sync() wasn't
called as it should be.
MFC after: 1 week
This way GEOM classes can safely detach from provider when an orphan
event is received. This fixes 'detach with active requests' panic for
gstripe/gconcat under load.
PR: kern/102766
Submitted by: mjacob
OK'ed by: phk
MFC after: 1 week
add count of active and total components to the launched line so you can
see at a glance if your mirror/raid3 is complete...
now:
GEOM_MIRROR: Device mirror/sam launched (2/2).
Reviewed by: pjd
- hold/release device in start/done routines, this will probably slow
down things a bit, but previous code was racy;
- only release device if g_gate_destroy() failed - if it succeeded device
is dead and there is nothing to release;
- various other changes which makes forcible destruction reliable.
MFC after: 3 days
created on Windows XP (and others maybe) were not detected.
We detected only those created with newfs_msdos(8).
Submitted by: Tobias Reifenberger <treif@mayn.de>
style(9)ified by: pjd
This way one will be able to use provider encrypted on eg. i386 on
eg. sparc64. This doesn't really buy us much today, because UFS isn't
endian agnostic.
We retain backward compatibility by setting G_ELI_FLAG_NATIVE_BYTE_ORDER
flag on devices with version number less than 2 and not converting the
offset.
o PMBR partitions count to the number of partitions on the disk, which
means that if a PMBR entry is invalid we will not treat the MBR as a
PMBR by virtue of it not describing any partitions.
Previously the checks were inconsistent in that an invalid PMBR entry
would be harmless when no other partitions exist (we would treat the
MBR as a PMBR by virtue of it being empty), but it would be fatal when
there is at least one other partition.
o The partition size of a PMBR partition is one less than the media size
because the GPT starts at the second sector (LBA 1) and extends to
the end of the media. For backward bug-compatibility we accept a size
that's exactly the media size (FreeBSD bug).
Also, when the partition size can not be represented in a 32-bit
integral, the partition size in the MBR is to be set to 0xFFFFFFFF.
Accept this as a valid size, even if the size can be represented.
we obtained access. It is possible that GPT gets to taste a disk
first, which means the disk has not been opened before and it will
not get opened until after we checked the mediasize and sectorsize.
However, since the mediasize and sectorsize are determined at open
and that happens when access is optained, checking the mediasize
and sectorsize before obtaining access may result in GPT rejecting
the disk.
uma(9) will be used for memory allocation.
In case of problems or tracking bugs, there are more useful tools for malloc(9)
debugging than for uma(9) debugging, like memguard(9) and redzone(9).
MFC after: 1 week
MBR should have only one entry of type 0xEE, consider protective MBR
to be one, that has at least one entry of type 0xEE covering the whole
unit. This makes GEOM_GPT compatible with disks partitioned by the
Apple's BootCamp.
Approved in principle by: marcel
MFC After: 1 month
offset or request size which is not a multiple of the sector size, make
sure that the bio is set to indicate that no data has actually been
transferred.
The result of this is that the file offset is no longer incremented for
these requests. The fact that the file offset was incremented broke
fdisk(8)'s probing of sector size for non-512 byte sector sizes.
Reviewed by: phk, cperciva
Submitted by: mdodd
MFC after: 2 weeks
By using a pointer to struct dos_partition, we implicitly tell the
compiler that the pointer is 4-bytes aligned, even though we know
that's not the case. The fact that we only dereference the pointer
to access a byte-wide field (field dp_ptyp) is not a guarantee that
the compiler will in fact use a byte-wide load. On some platforms
it's more efficient to use long word or quad word loads and use
bit-shifting and bit-masking to get the intended byte. On those
platforms an misaligned load will be the result.
The fix is to use byte-wide pointer arithmetic based on sizeof() and
offsetof() to avoid invalid casts which avoids that the compiler
makes invalid assumptions.
Backtrace provided by: wilko@
MFC after: 1 week
