tty: fix fu_list abuse
tty code abuses fu_list, which causes a bug in remount,ro handling.
If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".
Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.
The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.
[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]
Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs: fs_struct rwlock to spinlock
struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.
Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
gcc-4.6: ACPI: fix unused but set variables in ACPI
ACPI thermal: make procfs I/F depend on CONFIG_ACPI_PROCFS
ACPI video: make procfs I/F depend on CONFIG_ACPI_PROCFS
ACPI processor: remove deprecated ACPI procfs I/F
ACPI power_resource: remove unused procfs I/F
ACPI: remove deprecated ACPI procfs I/F
ACPI: introduce drivers/acpi/sysfs.c
ACPI: introduce module parameter acpi.aml_debug_output
ACPI: introduce drivers/acpi/debugfs.c
ACPI, APEI, ERST debug support
ACPI, APEI, Manage GHES as platform devices
ACPI, APEI, Rename CPER and GHES severity constants
ACPI, APEI, Fix a typo of error path of apei_resources_request
ACPI / ACPICA: Fix reference counting problems with GPE handlers
ACPI: Add the check of ADR flag in course of finding ACPI handle for PCI device
ACPI / Sleep: Drop acpi_suspend_finish()
ACPI / Sleep: Consolidate suspend and hibernation routines
ACPI / Wakeup: Simplify enabling of wakeup devices
ACPI / Sleep: Rework enabling wakeup devices
ACPI / Sleep: Free NVS copy if suspending of devices fails
Fixed up totally buggered "ACPI: fix unused but set variables in ACPI"
patch that doesn't even compile in the merge.
Thanks to Sedat Dilek <sedat.dilek@googlemail.com> for noticing the
breakage before I even pulled. And a big "Grrr.." at Len for not even
bothering to compile the tree before asking me to pull.
* git://git.infradead.org/mtd-2.6:
mtd/nand_ids: Fix buswidth
mtd/m25p80: fix test for end of loop
mtd/m25p80: retlen is never NULL
MIPS: Fix gen_nand probe structures contents
gen_nand: Test if nr_chips field is valid
BFIN: Fix gen_nand probe structures contents
nand/denali: move all hardware initialization work to denali_hw_init
nand/denali: Add a page check in denali_read_page & denali_read_page_raw
nand/denali: use cpu_relax() while waiting for hardware interrupt
nand/denali: change read_status function method
nand/denali: Fixed check patch warnings
ARM: Fix gen_nand probe structures contents
mtd/nand_base: fix kernel-doc warnings & typos
nand/denali: use dev_xx debug function to replace nand_dbg_print and some printk
nand/denali: Fixed handle ECC error bugs
nand/denali: use iowrite32() to replace denali_write32()
nand/denali: Fixed probe function bugs
* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
intel_idle: recognize Lincroft Atom Processor
intel_idle: no longer EXPERIMENTAL
intel_idle: disable module support
intel_idle: add support for Westmere-EX
intel_idle: delete power_policy modparam, and choose substate functions
intel_idle: delete substates DEBUG modparam
Mark the ACPI thermal procfs I/F deprecated, because /sys/class/thermal/
is already available and has been working for years w/o any problem.
The ACPI thermal procfs I/F will be removed in 2.6.37.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Mark ACPI video driver procfs I/F deprecated, including:
/proc/acpi/video/*/info
/proc/acpi/video/*/DOS
/proc/acpi/video/*/ROM
/proc/acpi/video/*/POST
/proc/acpi/video/*/POST_info
/proc/acpi/video/*/*/info
/proc/acpi/video/*/*/state
/proc/acpi/video/*/*/EDID
and
/proc/acpi/video/*/*/brightness, because
1. we already have the sysfs I/F /sysclass/backlight/ as the replacement
of /proc/acpi/video/*/*/brightness.
2. the other procfs I/F is not useful for userspace.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Remove deprecated ACPI processor procfs I/F, including:
/proc/acpi/processor/CPUX/power
/proc/acpi/processor/CPUX/limit
/proc/acpi/processor/CPUX/info
/proc/acpi/processor/CPUX/throttling still exists,
as we don't have sysfs I/F available for now.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Rmove deprecated ACPI procfs I/F, including
/proc/acpi/debug_layer
/proc/acpi/debug_level
/proc/acpi/info
/proc/acpi/dsdt
/proc/acpi/fadt
/proc/acpi/sleep
because the sysfs I/F is already available
and has been working well for years.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce drivers/acpi/sysfs.c.
code for ACPI sysfs I/F, including
#ifdef ACPI_DEBUG
/sys/module/acpi/parameters/debug_layer
/sys/module/acpi/parameters/debug_level
/sys/module/acpi/parameters/trace_method_name
/sys/module/acpi/parameters/trace_debug_layer
/sys/module/acpi/parameters/trace_debug_level
/sys/module/acpi/parameters/trace_state
#endif
/sys/module/acpi/parameters/acpica_version
/sys/firmware/acpi/tables/
/sys/firmware/acpi/interrupts/
is moved to this file.
No function change in this patch.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce module parameter acpi.aml_debug_output.
With acpi.aml_debug_output set, we can get AML debug object output
(Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.
Together with the runtime custom method mechanism,
we can debug AML code problems without rebuilding the kernel.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce drivers/acpi/debugfs.c.
Code for ACPI debugfs I/F,
i.e. /sys/kernel/debug/acpi/custom_method,
is moved to this file.
And make ACPI debugfs always built in,
even if CONFIG_ACPI_DEBUG is cleared.
BTW:this adds about 400bytes code to ACPI, when
CONFIG_ACPI_DEBUG is cleared.
[uaccess.h build fix from Andrew Morton <akpm@linux-foundation.org>]
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch adds debugging/testing support to ERST. A misc device is
implemented to export raw ERST read/write/clear etc operations to user
space. With this patch, we can add ERST testing support to
linuxfirmwarekit ISO (linuxfirmwarekit.org) to verify the kernel
support and the firmware implementation.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix fusion missing kernel-doc:
Warning(drivers/message/fusion/mptbase.c:649): No description found for parameter 'func_name'
Warning(drivers/message/fusion/mptbase.c:8010): No description found for parameter 'cb_idx'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin
Linus Torvalds
Len Brown
Andi Kleen
Zhang Rui
Arjan van de Ven
Huang Ying
Randy Dunlap