config BTRFS_FS
tristate "Btrfs filesystem support"
select CRYPTO
select CRYPTO_CRC32C
select ZLIB_INFLATE
select ZLIB_DEFLATE
select LZO_COMPRESS
select LZO_DECOMPRESS
select RAID6_PQ
select XOR_BLOCKS
select SRCU
help
Btrfs is a general purpose copy-on-write filesystem with extents,
writable snapshotting, support for multiple devices and many more
features focused on fault tolerance, repair and easy administration.
The filesystem disk format is no longer unstable, and it's not
expected to change unless there are strong reasons to do so. If there
is a format change, file systems with a unchanged format will
continue to be mountable and usable by newer kernels.
For more information, please see the web pages at
http://btrfs.wiki.kernel.org.
To compile this file system support as a module, choose M here. The
module will be called btrfs.
If unsure, say N.
config BTRFS_FS_POSIX_ACL
bool "Btrfs POSIX Access Control Lists"
depends on BTRFS_FS
select FS_POSIX_ACL
help
POSIX Access Control Lists (ACLs) support permissions for users and
groups beyond the owner/group/world scheme.
To learn more about Access Control Lists, visit the POSIX ACLs for
Linux website .
If you don't know what Access Control Lists are, say N
config BTRFS_FS_CHECK_INTEGRITY
bool "Btrfs with integrity check tool compiled in (DANGEROUS)"
depends on BTRFS_FS
help
Adds code that examines all block write requests (including
writes of the super block). The goal is to verify that the
state of the filesystem on disk is always consistent, i.e.,
after a power-loss or kernel panic event the filesystem is
in a consistent state.
If the integrity check tool is included and activated in
the mount options, plenty of kernel memory is used, and
plenty of additional CPU cycles are spent. Enabling this
functionality is not intended for normal use.
In most cases, unless you are a btrfs developer who needs
to verify the integrity of (super)-block write requests
during the run of a regression test, say N
config BTRFS_FS_RUN_SANITY_TESTS
bool "Btrfs will run sanity tests upon loading"
depends on BTRFS_FS
help
This will run some basic sanity tests on the free space cache
code to make sure it is acting as it should. These are mostly
regression tests and are only really interesting to btrfs
developers.
If unsure, say N.
config BTRFS_DEBUG
bool "Btrfs debugging support"
depends on BTRFS_FS
help
Enable run-time debugging support for the btrfs filesystem. This may
enable additional and expensive checks with negative impact on
performance, or export extra information via sysfs.
If unsure, say N.
config BTRFS_ASSERT
bool "Btrfs assert support"
depends on BTRFS_FS
help
Enable run-time assertion checking. This will result in panics if
any of the assertions trip. This is meant for btrfs developers only.
If unsure, say N.
gi/linux/net-next.git/commit/fs/xfs/xfs_message.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>xfs_message.c
x86/efi: Always map the first physical page into the EFI pagetables
Commit:
129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")
stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode.
It turns out though that there are 64-bit EFI implementations in the wild
(this particular problem has been reported on a Lenovo Yoga 710-11IKB),
which still make use of the first physical page for their own private use,
even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory
map.
In case there is no mapping for this particular frame in the EFI pagetables,
as soon as firmware tries to make use of it, a triple fault occurs and the
system reboots (in case of the Yoga 710-11IKB this is very early during bootup).
Fix that by always mapping the first page of physical memory into the EFI
pagetables. We're free to hand this page to the BIOS, as trim_bios_range()
will reserve the first page and isolate it away from memory allocators anyway.
Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the
regression on affected hardware, as this commit:
ab72a27da ("x86/efi: Consolidate region mapping logic")
later made the first physical frame not to be mapped anyway.
Reported-by: Hanka Pavlikova <hanka@ucw.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vojtech Pavlik <vojtech@ucw.cz>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: linux-efi@vger.kernel.org
Cc: stable@kernel.org # v4.8+
Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")
Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk
[ Tidied up the changelog and the comment. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>