I have translated some kernel documentation so I wish to maintain the
Chinese documentation in our kernel directories.
Signed-off-by: Harry Wei <harryxiyou@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In several places, an epoll fd can call another file's ->f_op->poll()
method with ep->mtx held. This is in general unsafe, because that other
file could itself be an epoll fd that contains the original epoll fd.
The code defends against this possibility in its own ->poll() method using
ep_call_nested, but there are several other unsafe calls to ->poll
elsewhere that can be made to deadlock. For example, the following simple
program causes the call in ep_insert recursively call the original fd's
->poll, leading to deadlock:
#include <unistd.h>
#include <sys/epoll.h>
int main(void) {
int e1, e2, p[2];
struct epoll_event evt = {
.events = EPOLLIN
};
e1 = epoll_create(1);
e2 = epoll_create(2);
pipe(p);
epoll_ctl(e2, EPOLL_CTL_ADD, e1, &evt);
epoll_ctl(e1, EPOLL_CTL_ADD, p[0], &evt);
write(p[1], p, sizeof p);
epoll_ctl(e1, EPOLL_CTL_ADD, e2, &evt);
return 0;
}
On insertion, check whether the inserted file is itself a struct epoll,
and if so, do a recursive walk to detect whether inserting this file would
create a loop of epoll structures, which could lead to deadlock.
[nelhage@ksplice.com: Use epmutex to serialize concurrent inserts]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Reported-by: Nelson Elhage <nelhage@ksplice.com>
Tested-by: Nelson Elhage <nelhage@ksplice.com>
Cc: <stable@kernel.org> [2.6.34+, possibly earlier]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
regulator, mc13xxx: Remove pointless test for unsigned less than zero
regulator: Fix warning with CONFIG_BUG disabled
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: fix fiemap bugs with delalloc
Btrfs: set FMODE_EXCL in btrfs_device->mode
Btrfs: make btrfs_rm_device() fail gracefully
Btrfs: Avoid accessing unmapped kernel address
Btrfs: Fix BTRFS_IOC_SUBVOL_SETFLAGS ioctl
Btrfs: allow balance to explicitly allocate chunks as it relocates
Btrfs: put ENOSPC debugging under a mount option
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86 quirk: Fix polarity for IRQ0 pin2 override on SB800 systems
x86/mrst: Fix apb timer rating when lapic timer is used
x86: Fix reboot problem on VersaLogic Menlow boards
The member of the rtc_class_ops struct is called alarm_irq_enable and
not alarm_irq_enabled
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jelle Martijn Kok <jmkok@youcom.nl>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
addr_type of 0 means that the type should be adopted from from_dev and
not from __hw_addr_del_multiple(). Unfortunately it isn't so and
addr_type will always be considered. Fix this by implementing the
considered and documented behavior.
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
BCM4320a breaks when enabling power save (bug 29732). So disable power save
for anything but BCM4320b that is known to work.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
"AirLive X.USB now works perfectly under a Linux
environment!"
Cc: <stable@kernel.org>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Commit 4df3071ebd "ath9k_hw: optimize
interrupt mask changes", changed ath9k_hw_set_interrupts function to
enable interrupts regardless of function argument, what could possibly
be wrong. Correct that behaviour and check "ints" arguments before
enabling interrupts, also disable interrupts if ints do not have
ATH9K_INT_GLOBAL flag set.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
CPU0 and CPU1 clockdomain is at the offset of 0x18 from the LPRM base.
The header file has set it wrongly to 0x0. Offset 0x0 is for CPUx power
domain control register
Fix the same.
The autogen scripts is fixed thanks to Benoit Cousson
With the old value, the clockdomain code would access the
*_PWRSTCTRL.POWERSTATE field when it thought it was accessing the
*_CLKSTCTRL.CLKTRCTRL field. In the worst case, this could cause
system power management to behave incorrectly.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
[paul@pwsan.com: added second paragraph to commit message]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
* 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
usb: musb: core: set has_tt flag
USB: xhci: mark local functions as static
USB: xhci: fix couple sparse annotations
USB: xhci: rework xhci_print_ir_set() to get ir set from xhci itself
USB: Reset USB 3.0 devices on (re)discovery
xhci: Fix an error in count_sg_trbs_needed()
xhci: Fix errors in the running total calculations in the TRB math
xhci: Clarify some expressions in the TRB math
xhci: Avoid BUG() in interrupt context
* 'for-linus' of git://neil.brown.name/md:
md: Fix - again - partition detection when array becomes active
Fix over-zealous flush_disk when changing device size.
md: avoid spinlock problem in blk_throtl_exit
md: correctly handle probe of an 'mdp' device.
md: don't set_capacity before array is active.
md: Fix raid1->raid0 takeover
With slab poisoning enabled, I see the following oops:
Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6b73
...
NIP [c0000000006bc61c] .rxrpc_destroy+0x44/0x104
LR [c0000000006bc618] .rxrpc_destroy+0x40/0x104
Call Trace:
[c0000000feb2bc00] [c0000000006bc618] .rxrpc_destroy+0x40/0x104 (unreliable)
[c0000000feb2bc90] [c000000000349b2c] .key_cleanup+0x1a8/0x20c
[c0000000feb2bd40] [c0000000000a2920] .process_one_work+0x2f4/0x4d0
[c0000000feb2be00] [c0000000000a2d50] .worker_thread+0x254/0x468
[c0000000feb2bec0] [c0000000000a868c] .kthread+0xbc/0xc8
[c0000000feb2bf90] [c000000000020e00] .kernel_thread+0x54/0x70
We aren't initialising token->next, but the code in destroy_context relies
on the list being NULL terminated. Use kzalloc to zero out all the fields.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I'm seeing the following oops when testing afs:
Unable to handle kernel paging request for data at address 0x00000008
...
NIP [c0000000003393b0] .afs_unlink_writeback+0x38/0xc0
LR [c00000000033987c] .afs_put_writeback+0x98/0xec
Call Trace:
[c00000000345f600] [c00000000033987c] .afs_put_writeback+0x98/0xec
[c00000000345f690] [c00000000033ae80] .afs_write_begin+0x6a4/0x75c
[c00000000345f790] [c00000000012b77c] .generic_file_buffered_write+0x148/0x320
[c00000000345f8d0] [c00000000012e1b8] .__generic_file_aio_write+0x37c/0x3e4
[c00000000345f9d0] [c00000000012e2a8] .generic_file_aio_write+0x88/0xfc
[c00000000345fa90] [c0000000003390a8] .afs_file_write+0x10c/0x178
[c00000000345fb40] [c000000000188788] .do_sync_write+0xc4/0x128
[c00000000345fcc0] [c000000000189658] .vfs_write+0xe8/0x1d8
[c00000000345fd70] [c000000000189884] .SyS_write+0x68/0xb0
[c00000000345fe30] [c000000000008564] syscall_exit+0x0/0x40
afs_write_begin hits an error and calls afs_unlink_writeback. In there
we do list_del_init on an uninitialised list.
The patch below initialises ->link when creating the afs_writeback struct.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before this patch issuing these commands:
fd = open("/proc/sys/net/ipv6/route/flush")
unshare(CLONE_NEWNET)
write(fd, "stuff")
would flush the newly created net, not the original one.
The equivalent ipv4 code is correct (stores the net inside ->extra1).
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit e1181ee6 "vfs: pass struct file to do_truncate on O_TRUNC
opens" broke the behavior of open(O_TRUNC|O_RDONLY) in fuse. Fuse
assumed that when called from open, a truncate() will be done, not an
ftruncate().
Fix by restoring the old behavior, based on the ATTR_OPEN flag.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Single threaded NTFS-3G could get stuck if a delayed RELEASE reply
triggered a DESTROY request via path_put().
Fix this by
a) making RELEASE requests synchronous, whenever possible, on fuseblk
filesystems
b) if not possible (triggered by an asynchronous read/write) then do
the path_put() in a separate thread with schedule_work().
Reported-by: Oliver Neukum <oneukum@suse.de>
Cc: stable@kernel.org
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
commit f0fba2ad1b included a mistake
on the name of the platform in the snd_soc_dai_link structure.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Correct names for pxa AC97 DAI are pxa2xx-ac97 and pxa2xx-ac97-aux. Fix
that for all PXA platforms.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
The variable 'val' is a 'unsigned int', so it can never be less than zero.
This fact makes the "val < 0" part of the test done in BUG_ON() in
mc13xxx_regulator_get_voltage() rather pointles since it can never have
any effect.
This patch removes the pointless test.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
The API for network devices has changed so that setting carrier off at
probe is no longer required. This should fix the IPv6 addrconf issue.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=29612
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Reported-by: George Billios <gbillios@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/i915: Fix unintended recursion in ironlake_disable_rc6
drm/i915: fix corruptions on i8xx due to relaxed fencing
drm/i915: skip FDI & PCH enabling for DP_A
agp/intel: Experiment with a 855GM GWB bit
drm/i915: don't enable FDI & transcoder interrupts after all
drm/i915: Ignore a hung GPU when flushing the framebuffer prior to a switch
OMAP2+ kernels built without CONFIG_OMAP_32K_TIMER crash on boot after the
2.6.38 sched_clock changes:
[ 0.000000] OMAP clockevent source: GPTIMER1 at 13000000 Hz
[ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 0.000000] pgd = c0004000
[ 0.000000] [00000000] *pgd=00000000
[ 0.000000] Internal error: Oops: 80000005 [#1] SMP
[ 0.000000] last sysfs file:
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 Not tainted (2.6.38-rc5-00057-g04aa67d #152)
[ 0.000000] PC is at 0x0
[ 0.000000] LR is at sched_clock_poll+0x2c/0x3c
Without CONFIG_OMAP_32K_TIMER, the kernel has an clockevent and
clocksource resolution about three orders of magnitude higher than
with CONFIG_OMAP_32K_TIMER set. The tradeoff is that the lowest
power consumption states are not available.
Fix by calling init_sched_clock() from the GPTIMER clocksource init code.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
On some SB800 systems polarity for IOAPIC pin2 is wrongly
specified as low active by BIOS. This caused system hangs after
resume from S3 when HPET was used in one-shot mode on such
systems because a timer interrupt was missed (HPET signal is
high active).
For more details see:
http://marc.info/?l=linux-kernel&m=129623757413868
Tested-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: stable@kernel.org # 37.x, 32.x
LKML-Reference: <20110224145346.GD3658@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
MUSB is a non-standard host implementation which
can handle all speeds with the same core. We need
to set has_tt flag after commit
d199c96d41 (USB: prevent
buggy hubs from crashing the USB stack) in order for
MUSB HCD to continue working.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Cc: stable <stable@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Michael Jones <michael.jones@matrix-vision.de>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit bba63a2 (ACPICA: Implicit notify support) introduced a
mechanism that causes a notify request of type
ACPI_NOTIFY_DEVICE_WAKE to be queued automatically by
acpi_ev_asynch_execute_gpe_method() for the device whose _PRW points
to the GPE being handled if that GPE is not associated with an
_Lxx/_Exx method. However, it turns out that on some systems there
are multiple devices with _PRW pointing to the same GPE without
_Lxx/_Exx and the mechanism introduced by commit bba63a2 needs to be
extended so that "implicit" notify requests of type
ACPI_NOTIFY_DEVICE_WAKE can be queued automatically for all those
devices at the same time.
Reported-and-tested-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
File position is not controlled, it may lead to overwrites of arbitrary
kernel memory. Also the code may kfree() the same pointer multiple
times.
One more flaw is still present: if multiple processes open the file then
all 3 static variables are shared, leading to various race conditions.
They should be moved to file->private_data.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Reviewed-by: Eugene Teo <eugeneteo@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit 074037e (PM / Wakeup: Introduce wakeup source objects and
event statistics (v3)) caused ACPI wakeup to only work if
CONFIG_PM_SLEEP is set, but it also worked for CONFIG_PM_SLEEP unset
before. This can be fixed by making device_set_wakeup_enable(),
device_init_wakeup() and device_may_wakeup() work in the same way
as before commit 074037e when CONFIG_PM_SLEEP is unset.
Reported-and-tested-by: Justin Maggard <jmaggard10@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
After disabling, we're meant to teardown the bo used for the contexts,
not recurse into ourselves again and preventing module unload.
Reported-and-tested-by: Ben Widawsky <bwidawsk@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Also fix number of 92HD87 pins to exclude invalid pins.
Signed-off-by: Vitaliy Kulikov <Vitaliy.Kulikov@idt.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The new implementation of bd_link_disk_holder() added by 49731baa41
(block: restore multiple bd_link_disk_holder() support) didn't get an
extra reference for the holder_dir kobject of the slave bdev; however,
bdev kills holder_dir on removal, not release, so if the slave bdev is
removed while there are holder links, the holder_dir will be destroyed
while there still are holder links, which leads to oops later when
bd_unlink_disk_order() tries to remove those links.
Make bd_link_disk_holder() grab an extra reference for the slave's
holder_dir and put it in bd_unlink_disk_holder().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
Tested-by: "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Grab a reference to bdev before calling blkdev_get(), which expects
the refcount to be already incremented and either returns success or
decrements the refcount and returns an error.
The bug was introduced by e525fd89 (block: make blkdev_get/put()
handle exclusive access), which didn't take into account this behavior
of blkdev_get().
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adam Kovari and others reported that disconnecting an USB drive with
an ntfs-3g filesystem would cause "kernel BUG at fs/inode.c:1421!" to
be triggered.
The BUG could be traced back to ioctl(BLKBSZSET), which would
erroneously decrement the refcount on the bdev. This is because
blkdev_get() expects the refcount to be already incremented and either
returns success or decrements the refcount and returns an error.
The bug was introduced by e525fd89 (block: make blkdev_get/put()
handle exclusive access), which didn't take into account this behavior
of blkdev_get().
This fixes
https://bugzilla.kernel.org/show_bug.cgi?id=29202
(and likely 29792 too)
Reported-by: Adam Kovari <kovariadam@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Need to adjust the clockevent device rating for the structure
that will be registered with clockevent system instead of the
temporary structure.
Without this fix, APB timer rating will be higher than LAPIC
timer such that it can not be released later to be used as the
broadcast timer.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
LKML-Reference: <1298506046-439-1-git-send-email-jacob.jun.pan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
By the commit
b3e19d9 2011-01-07 fs: scale mntget/mntput
vfsmount_lock was introduced around testing mnt_count.
Fix the mis-typed 'unlock'
Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Revert
b821eaa572
and
f3b99be19d
When I wrote the first of these I had a wrong idea about the
lifetime of 'struct block_device'. It can disappear at any time that
the block device is not open if it falls out of the inode cache.
So relying on the 'size' recorded with it to detect when the
device size has changed and so we need to revalidate, is wrong.
Rather, we really do need the 'changed' attribute stored directly in
the mddev and set/tested as appropriate.
Without this patch, a sequence of:
mknod / open / close / unlink
(which can cause a block_device to be created and then destroyed)
will result in a rescan of the partition table and consequence removal
and addition of partitions.
Several of these in a row can get udev racing to create and unlink and
other code can get confused.
With the patch, the rescan is only performed when needed and so there
are no races.
This is suitable for any stable kernel from 2.6.35.
Reported-by: "Wojcik, Krzysztof" <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
There are two cases when we call flush_disk.
In one, the device has disappeared (check_disk_change) so any
data will hold becomes irrelevant.
In the oter, the device has changed size (check_disk_size_change)
so data we hold may be irrelevant.
In both cases it makes sense to discard any 'clean' buffers,
so they will be read back from the device if needed.
In the former case it makes sense to discard 'dirty' buffers
as there will never be anywhere safe to write the data. In the
second case it *does*not* make sense to discard dirty buffers
as that will lead to file system corruption when you simply enlarge
the containing devices.
flush_disk calls __invalidate_devices.
__invalidate_device calls both invalidate_inodes and invalidate_bdev.
invalidate_inodes *does* discard I_DIRTY inodes and this does lead
to fs corruption.
invalidate_bev *does*not* discard dirty pages, but I don't really care
about that at present.
So this patch adds a flag to __invalidate_device (calling it
__invalidate_device2) to indicate whether dirty buffers should be
killed, and this is passed to invalidate_inodes which can choose to
skip dirty inodes.
flusk_disk then passes true from check_disk_change and false from
check_disk_size_change.
dm avoids tripping over this problem by calling i_size_write directly
rathher than using check_disk_size_change.
md does use check_disk_size_change and so is affected.
This regression was introduced by commit 608aeef17a which causes
check_disk_size_change to call flush_disk, so it is suitable for any
kernel since 2.6.27.
Cc: stable@kernel.org
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Andrew Patterson <andrew.patterson@hp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NeilBrown <neilb@suse.de>
Robert Swiecki reported a BUG_ON(page_mapped) from a fuzzer, punching
a hole with madvise(,, MADV_REMOVE). That path is under mutex, and
cannot be explained by lack of serialization in unmap_mapping_range().
Reviewing the code, I found one place where vm_truncate_count handling
should have been updated, when I switched at the last minute from one
way of managing the restart_addr to another: mremap move changes the
virtual addresses, so it ought to adjust the restart_addr.
But rather than exporting the notion of restart_addr from memory.c, or
converting to restart_pgoff throughout, simply reset vm_truncate_count
to 0 to force a rescan if mremap move races with preempted truncation.
We have no confirmation that this fixes Robert's BUG,
but it is a fix that's worth making anyway.
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Leun reported that running parallel opens on a fuse filesystem
can trigger a "kernel BUG at mm/truncate.c:475"
Gurudas Pai reported the same bug on NFS.
The reason is, unmap_mapping_range() is not prepared for more than
one concurrent invocation per inode. For example:
thread1: going through a big range, stops in the middle of a vma and
stores the restart address in vm_truncate_count.
thread2: comes in with a small (e.g. single page) unmap request on
the same vma, somewhere before restart_address, finds that the
vma was already unmapped up to the restart address and happily
returns without doing anything.
Another scenario would be two big unmap requests, both having to
restart the unmapping and each one setting vm_truncate_count to its
own value. This could go on forever without any of them being able to
finish.
Truncate and hole punching already serialize with i_mutex. Other
callers of unmap_mapping_range() do not, and it's difficult to get
i_mutex protection for all callers. In particular ->d_revalidate(),
which calls invalidate_inode_pages2_range() in fuse, may be called
with or without i_mutex.
This patch adds a new mutex to 'struct address_space' to prevent
running multiple concurrent unmap_mapping_range() on the same mapping.
[ We'll hopefully get rid of all this with the upcoming mm
preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex
lockbreak" patch in particular. But that is for 2.6.39 ]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reported-by: Michael Leun <lkml20101129@newton.leun.net>
Reported-by: Gurudas Pai <gurudas.pai@oracle.com>
Tested-by: Gurudas Pai <gurudas.pai@oracle.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 556ea928f7.
Jeff Chua reports that it can cause some bluetooth devices (he mentions
an Bluetooth Intermec scanner) to just stop responding after a while
with messages like
[ 4533.361959] btusb 8-1:1.0: no reset_resume for driver btusb?
[ 4533.361964] btusb 8-1:1.1: no reset_resume for driver btusb?
from the kernel. See also
https://bugzilla.kernel.org/show_bug.cgi?id=26182
for other reports.
Reported-by: Jeff Chua <jeff.chua.linux@gmail.com>
Reported-by: Andrew Meakovski <meako@bigmir.net>
Reported-by: Jim Faulkner <jfaulkne@ccs.neu.edu>
Acked-by: Greg KH <gregkh@suse.de>
Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Cc: stable@kernel.org (for 2.6.37)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
