config UBIFS_FS
tristate "UBIFS file system support"
select CRC16
select CRC32
select CRYPTO if UBIFS_FS_ADVANCED_COMPR
select CRYPTO if UBIFS_FS_LZO
select CRYPTO if UBIFS_FS_ZLIB
select CRYPTO_LZO if UBIFS_FS_LZO
select CRYPTO_DEFLATE if UBIFS_FS_ZLIB
depends on MTD_UBI
help
UBIFS is a file system for flash devices which works on top of UBI.
config UBIFS_FS_ADVANCED_COMPR
bool "Advanced compression options"
depends on UBIFS_FS
help
This option allows to explicitly choose which compressions, if any,
are enabled in UBIFS. Removing compressors means inability to read
existing file systems.
If unsure, say 'N'.
config UBIFS_FS_LZO
bool "LZO compression support" if UBIFS_FS_ADVANCED_COMPR
depends on UBIFS_FS
default y
help
LZO compressor is generally faster than zlib but compresses worse.
Say 'Y' if unsure.
config UBIFS_FS_ZLIB
bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR
depends on UBIFS_FS
default y
help
Zlib compresses better than LZO but it is slower. Say 'Y' if unsure.
config UBIFS_ATIME_SUPPORT
bool "Access time support" if UBIFS_FS
depends on UBIFS_FS
default n
help
Originally UBIFS did not support atime, because it looked like a bad idea due
increased flash wear. This option adds atime support and it is disabled by default
to preserve the old behavior. If you enable this option, UBIFS starts updating atime,
which means that file-system read operations will cause writes (inode atime
updates). This may affect file-system performance and increase flash device wear,
so be careful. How often atime is updated depends on the selected strategy:
strictatime is the "heavy", relatime is "lighter", etc.
If unsure, say 'N'
config UBIFS_FS_ENCRYPTION
bool "UBIFS Encryption"
depends on UBIFS_FS && BLOCK
select FS_ENCRYPTION
default n
help
Enable encryption of UBIFS files and directories. This
feature is similar to ecryptfs, but it is more memory
efficient since it avoids caching the encrypted and
decrypted pages in the page cache.
iff/include/drm/bridge/mhl.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>diff
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.
It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server. The call chains were different:
- VT ioctl(KDSETMODE, KD_TEXT):
intel_cleanup_plane_fb+0x5b/0xa0 [i915]
drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
intel_atomic_commit_tail+0x749/0xfe0 [i915]
intel_atomic_commit+0x3cb/0x4f0 [i915]
drm_atomic_commit+0x4b/0x50 [drm]
restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
intel_fbdev_set_par+0x18/0x70 [i915]
fb_set_var+0x236/0x460
fbcon_blank+0x30f/0x350
do_unblank_screen+0xd2/0x1a0
vt_ioctl+0x507/0x12a0
tty_ioctl+0x355/0xc30
do_vfs_ioctl+0xa3/0x5e0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x13/0x94
- i915 unpin_work workqueue:
intel_unpin_work_fn+0x58/0x140 [i915]
process_one_work+0x1f1/0x480
worker_thread+0x48/0x4d0
kthread+0x101/0x140
and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.
Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.
[ Reported it originally to the i915 developers on Jan 8, applying the
ugly workaround on my own now after triggering the problem for the
second time with no feedback.
This is likely to be the same bug reported as
https://bugs.freedesktop.org/show_bug.cgi?id=98829
https://bugs.freedesktop.org/show_bug.cgi?id=99134
which has a patch for the underlying problem, but it hasn't gotten to
me, so I'm applying the workaround. ]
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>