Freezer synchronization is needlessly complicated - it's by no means a
hot path and the priority is staying unintrusive and safe. This patch
makes it simply use a dedicated lock instead of piggy-backing on
task_lock() and playing with memory barriers.
On the failure path of try_to_freeze_tasks(), locking is moved from it
to cancel_freezing(). This makes the frozen() test racy but the race
here is a non-issue as the warning is printed for tasks which failed
to enter frozen for 20 seconds and race on PF_FROZEN at the last
moment doesn't change anything.
This simplifies freezer implementation and eases further changes
including some race fixes.
Signed-off-by: Tejun Heo <[email protected]>
There's no point in thawing nosig tasks before others. There's no
ordering requirement between the two groups on thaw, which the staged
thawing can't guarantee anyway. Simplify thaw_processes() by removing
the distinction and collapsing thaw_tasks() into thaw_processes().
This will help further updates to freezer.
Signed-off-by: Tejun Heo <[email protected]>
clear_freeze_flag() in exit_mm() is racy. Freezing can start
afterwards. Remove it. Skipping freezer for exiting task will be
properly implemented later.
Also, freezable() was testing exit_state directly to make system
freezer ignore dead tasks. Let the exiting task set PF_NOFREEZE after
entering TASK_DEAD instead.
Signed-off-by: Tejun Heo <[email protected]>
Cc: Oleg Nesterov <[email protected]>
thaw_process() now has only internal users - system and cgroup
freezers. Remove the unnecessary return value, rename, unexport and
collapse __thaw_process() into it. This will help further updates to
the freezer code.
-v3: oom_kill grew a use of thaw_process() while this patch was
pending. Convert it to use __thaw_task() for now. In the longer
term, this should be handled by allowing tasks to die if killed
even if it's frozen.
-v2: minor style update as suggested by Matt.
Signed-off-by: Tejun Heo <[email protected]>
Cc: Paul Menage <[email protected]>
Cc: Matt Helsley <[email protected]>
Writeback and thinkpad_acpi have been using thaw_process() to prevent
deadlock between the freezer and kthread_stop(); unfortunately, this
is inherently racy - nothing prevents freezing from happening between
thaw_process() and kthread_stop().
This patch implements kthread_freezable_should_stop() which enters
refrigerator if necessary but is guaranteed to return if
kthread_stop() is invoked. Both thaw_process() users are converted to
use the new function.
Note that this deadlock condition exists for many of freezable
kthreads. They need to be converted to use the new should_stop or
freezable workqueue.
Tested with synthetic test case.
Signed-off-by: Tejun Heo <[email protected]>
Acked-by: Henrique de Moraes Holschuh <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Oleg Nesterov <[email protected]>
There is no reason to export two functions for entering the
refrigerator. Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.
* Rename refrigerator() to __refrigerator() and make it return bool
indicating whether it scheduled out for freezing.
* Update try_to_freeze() to return bool and relay the return value of
__refrigerator() if freezing().
* Convert all refrigerator() users to try_to_freeze().
* Update documentation accordingly.
* While at it, add might_sleep() to try_to_freeze().
Signed-off-by: Tejun Heo <[email protected]>
Cc: Samuel Ortiz <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: Steven Whitehouse <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: KONISHI Ryusuke <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Some drivers set PF_NOFREEZE in their kthread functions which is
completely unnecessary and racy - some part of freezer code doesn't
consider cases where PF_NOFREEZE is set asynchronous to freezer
operations.
In general, there's no reason to allow setting PF_NOFREEZE explicitly.
Remove them and change the documentation to note that setting
PF_NOFREEZE directly isn't allowed.
-v2: Dropped change to twl4030-irq.c as it no longer uses PF_NOFREEZE.
Signed-off-by: Tejun Heo <[email protected]>
Acked-by: "Gustavo F. Padovan" <[email protected]>
Acked-by: Samuel Ortiz <[email protected]>
Cc: Marcel Holtmann <[email protected]>
Cc: wwang <[email protected]>
refrigerator() saves current->state before entering frozen state and
restores it before returning using __set_current_state(); however,
this is racy, for example, please consider the following sequence.
set_current_state(TASK_INTERRUPTIBLE);
try_to_freeze();
if (kthread_should_stop())
break;
schedule();
If kthread_stop() races with ->state restoration, the restoration can
restore ->state to TASK_INTERRUPTIBLE after kthread_stop() sets it to
TASK_RUNNING but kthread_should_stop() may still see zero
->should_stop because there's no memory barrier between restoring
TASK_INTERRUPTIBLE and kthread_should_stop() test.
This isn't restricted to kthread_should_stop(). current->state is
often used in memory barrier based synchronization and silently
restoring it w/o mb breaks them.
Use set_current_state() instead.
Signed-off-by: Tejun Heo <[email protected]>
* 'dev' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix up a undefined error in ext4_free_blocks in debugging code
ext4: add blk_finish_plug in error case of writepages.
ext4: Remove kernel_lock annotations
ext4: ignore journalled data options on remount if fs has no journal
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
libceph: Allocate larger oid buffer in request msgs
ceph: initialize root dentry
ceph: fix iput race when queueing inode work
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
VFS: Log the fact that we've given ELOOP rather than creating a loop
minixfs: kill manual hweight(), simplify
fs/minix: Verify bitmap block counts before mounting
The log replay code only partially loads block groups, since
the block group caching code is able to detect and deal with
extents the logging code has pinned down.
While the logging code is pinning down block groups, there is
a bogus WARN_ON we're hitting if the code wasn't able to find
an extent in the cache. This commit removes the warning because
it can happen any time there isn't a valid free space cache
for that block group.
Signed-off-by: Chris Mason <[email protected]>
To prevent an NFS server from being used to create a directory loop in an NFS
superblock on the client, the following patch was committed:
commit 1836750115
Author: Al Viro <[email protected]>
Date: Tue Jul 12 21:42:24 2011 -0400
Subject: fix loop checks in d_materialise_unique()
This causes ELOOP to be reported to anyone trying to access the dentry that
would otherwise cause the kernel to complete the loop.
However, no indication is given to the caller as to why an operation that ought
to work doesn't. The fault is with the kernel, which doesn't want to try and
solve the problem as it gets horrendously messy if there's another mountpoint
somewhere in the trees being spliced that can't be moved[*].
[*] The real problem is that we don't handle the excision of a subtree that
gets moved _out_ of what we can see. This can happen on the server where a
directory is merely moved between two other dirs on the same filesystem, but
where destination dir is not accessible by the client.
So, given the choice to return ELOOP rather than trying to reconfigure the
dentry tree, we should give the caller some indication of why they aren't being
allowed to make what should be a legitimate request and log a message.
Signed-off-by: David Howells <[email protected]>
Acked-by: Sachin Prabhu <[email protected]>
Signed-off-by: Al Viro <[email protected]>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (86 commits)
ipv4: fix redirect handling
ping: dont increment ICMP_MIB_INERRORS
sky2: fix hang in napi_disable
sky2: enforce minimum ring size
bonding: Don't allow mode change via sysfs with slaves present
f_phonet: fix page offset of first received fragment
stmmac: fix pm functions avoiding sleep on spinlock
stmmac: remove spin_lock in stmmac_ioctl.
stmmac: parameters auto-tuning through HW cap reg
stmmac: fix advertising 1000Base capabilties for non GMII iface
stmmac: use mdelay on timeout of sw reset
sky2: version 1.30
sky2: used fixed RSS key
sky2: reduce default Tx ring size
sky2: rename up/down functions
sky2: pci posting issues
sky2: fix hang on shutdown (and other irq issues)
r6040: fix check against MCRO_HASHEN bit in r6040_multicast_list
MAINTAINERS: change email address for shemminger
pch_gbe: Move #include of module.h
...
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / Suspend: Fix bug in suspend statistics update
PM / Hibernate: Fix the early termination of test modes
PM / shmobile: Fix build of sh7372_pm_init() for CONFIG_PM unset
PM Sleep: Do not extend wakeup paths to devices with ignore_children set
PM / driver core: disable device's runtime PM during shutdown
PM / devfreq: correct Kconfig dependency
PM / devfreq: fix use after free in devfreq_remove_device
PM / shmobile: Avoid restoring the INTCS state during initialization
PM / devfreq: Remove compiler error after irq.h update
PM / QoS: Properly use the WARN() macro in dev_pm_qos_add_request()
PM / Clocks: Only disable enabled clocks in pm_clk_suspend()
ARM: mach-shmobile: sh7372 A3SP no_suspend_console fix
PM / shmobile: Don't skip debugging output in pd_power_up()
We've been hitting BUG()'s in btrfs_cont_expand and btrfs_fallocate and anywhere
else that calls btrfs_get_extent while running xfstests 13 in a loop. This is
because fiemap is calling btrfs_get_extent with non-sectorsize aligned offsets,
which will end up adding mappings that are not sectorsize aligned, which will
cause problems in some cases for subsequent calls to btrfs_get_extent for
similar areas that are sectorsize aligned. With this patch I ran xfstests 13 in
a loop for a couple of hours and didn't hit the problem that I could previously
hit in at most 20 minutes. Thanks,
Signed-off-by: Josef Bacik <[email protected]>
When doing the io_ctl helpers to clean up the free space cache stuff I stopped
using our normal prepare_pages stuff, which means I of course forgot to do
things like set the pages extent mapped, which will cause us all sorts of
wonderful propblems. Thanks,
Signed-off-by: Josef Bacik <[email protected]>
We've been hitting panics when running xfstest 13 in a loop for long periods of
time. And actually this problem has always existed so we've been hitting these
things randomly for a while. Basically what happens is we get a thread coming
into the allocator and reading the space cache off of disk and adding the
entries to the free space cache as we go. Then we get another thread that comes
in and tries to allocate from that block group. Since block_group->cached !=
BTRFS_CACHE_NO it goes ahead and tries to do the allocation. We do this because
if we're doing the old slow way of caching we don't want to hold people up and
wait for everything to finish. The problem with this is we could end up
discarding the space cache at some arbitrary point in the future, which means we
could very well end up allocating space that is either bad, or when the real
caching happens it could end up thinking the space isn't in use when it really
is and cause all sorts of other problems.
The solution is to add a new flag to indicate we are loading the free space
cache from disk, and always try to cache the block group if cache->cached !=
BTRFS_CACHE_FINISHED. That way if we are loading the space cache anybody else
who tries to allocate from the block group will have to wait until it's finished
to make sure it completes successfully. Thanks,
Signed-off-by: Josef Bacik <[email protected]>
For the user it is confusing to find something like:
[10197.627710] new size for /dev/mapper/vg0-usr_share is 3221225472
in kernel log, because it doesn't point directly to btrfs.
This patch prefixes those messages with "btrfs:" like other btrfs
related printks.
Signed-off-by: Arnd Hannemann <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
Round inode bytes and delalloc bytes up to real blocksize before
converting to sector size. Otherwise eg. files smaller than 512
are reported with zero blocks due to incorrect rounding.
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
setup_cluster_no_bitmap() searches all the extents and bitmaps starting
from offset. Therefore if it returns -ENOSPC, all the bitmaps starting
from offset are in the bitmaps list, so it's sufficient to search from
this list in setup_cluser_bitmap().
Signed-off-by: Li Zefan <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
Suppose there are two bitmaps [0, 256], [256, 512] and one extent
[100, 120] in the free space cache, and we want to setup a cluster
with offset=100, bytes=50.
In this case, there will be only one bitmap [256, 512] in the temporary
bitmaps list, and then setup_cluster_bitmap() won't search bitmap [0, 256].
The cause is, the list is constructed in setup_cluster_no_bitmap(),
and only bitmaps with bitmap_entry->offset >= offset will be added
into the list, and the very bitmap that convers offset has
bitmap_entry->offset <= offset.
Signed-off-by: Li Zefan <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
My previous patch introduced some u64 for failed_mirror variables, this one
makes it consistent again.
Signed-off-by: Jan Schmidt <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
This patch casts to unsigned long before casting to a pointer and fixes
the following warnings:
fs/btrfs/extent_io.c:2289:20: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
fs/btrfs/ioctl.c:2933:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
fs/btrfs/ioctl.c:2937:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
fs/btrfs/ioctl.c:3020:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
fs/btrfs/scrub.c:275:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
fs/btrfs/backref.c:686:27: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
Signed-off-by: Jeff Mahoney <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
When btrfs is writing the super blocks, it send barrier flushes to make
sure writeback caching drives get all the metadata on disk in the
right order.
But, we have two bugs in the way these are sent down. When doing
full commits (not via the tree log), we are sending the barrier down
before the last super when it should be going down before the first.
In multi-device setups, we should be waiting for the barriers to
complete on all devices before writing any of the supers.
Both of these bugs can cause corruptions on power failures. We fix it
with some new code to send down empty barriers to all devices before
writing the first super.
Alexandre Oliva found the multi-device bug. Arne Jansen did the async
barrier loop.
Signed-off-by: Chris Mason <[email protected]>
Reported-by: Alexandre Oliva <[email protected]>
Prevent tracing of preempt_disable() in get_cpu_var() in
kvm_clock_read(). When CONFIG_DEBUG_PREEMPT is enabled,
preempt_disable/enable() are traced and this causes the function_graph
tracer to go into an infinite recursion. By open coding the
preempt_disable() around the get_cpu_var(), we can use the notrace
version which prevents preempt_disable/enable() from being traced and
prevents the recursion.
Based on a similar patch for Xen from Jeremy Fitzhardinge.
Tested-by: Gleb Natapov <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
This adds a new optional chunk to the CS ioctl that specifies optional flags
to the CS parser. Why this is useful is explained below. Note that some regs
no longer need the NOP relocation packet if this feature is enabled.
Tested on r300g and r600g with this flag disabled and enabled.
Assume there are two contexts sharing the same mipmapped tiled texture.
One context wants to render into the first mipmap and the other one
wants to render into the last mipmap. As you probably know, the hardware
has a MACRO_SWITCH feature, which turns off macro tiling for small mipmaps,
but that only applies to samplers.
(at least on r300-r500, though later hardware likely behaves the same)
So we want to just re-set the tiling flags before rendering (writing
packets), right? ... No. The contexts run in parallel, so they may
set the tiling flags simultaneously and then fire their command streams
also simultaneously. The last one setting the flags wins, the other one
loses.
Another problem is when one context wants to render into the first and
the last mipmap in one CS. Impossible. It must flush before changing
tiling flags and do the rendering into the smaller mipmaps in another CS.
Yet another problem is that writing copy_blit in userspace would be a mess
involving re-setting tiling flags to please the kernel, and causing races
with other contexts at the same time.
The only way out of this is to send tiling flags with each CS, ideally
with each relocation. But we already do that through the registers.
So let's just use what we have in the registers.
Signed-off-by: Marek Olšák <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (exynos4_tmu) Fix Kconfig dependency
[ Merging code in-flight, just because I can. What timezone should I
use? - Linus ]
Newer versions of MINIX can create filesystems that allocate an extra
bitmap block. Mounting of this succeeds, but doing a statfs call will
result in an oops in count_free because of a negative number being used
for the bh index.
Avoid this by verifying the number of allocated blocks at mount time,
erroring out if there are not enough and make statfs ignore the extras
if there are too many.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=18792
Signed-off-by: Josh Boyer <[email protected]>
Signed-off-by: Al Viro <[email protected]>
After commit 2a77c46de1
(PM / Suspend: Add statistics debugfs file for suspend to RAM)
a missing pair of braces inside the state_store() function causes even
invalid arguments to suspend to be wrongly treated as failed suspend
attempts. Fix this.
[rjw: Put the hash/subject of the buggy commit into the changelog.]
Signed-off-by: Srivatsa S. Bhat <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Dummy, non-zero definitions for HPAGE_MASK and HPAGE_SIZE were added in
51c6f666fc ("mm: ZAP_BLOCK causes redundant work") to avoid a divide
by zero in generic kernel code.
That code has since been removed, but probably should never have been
added in the first place: we don't want HPAGE_SIZE to act like PAGE_SIZE
for code that is working with hugepages, for example, when the
dependency on CONFIG_HUGETLB_PAGE has not been fulfilled.
Because hugepage size can differ from architecture to architecture, each
is required to have their own definitions for both HPAGE_MASK and
HPAGE_SIZE. This is always done in arch/*/include/asm/page.h.
So, just remove the dummy and dangerous definitions since they are no
longer needed and reveals the correct dependencies. Tested on
architectures using the definitions with allyesconfig: x86 (even with
thp), hppa, mips, powerpc, s390, sh3, sh4, sparc, and sparc64, and with
defconfig on ia64.
Signed-off-by: David Rientjes <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
new helper: mount_subtree()
switch create_mnt_ns() to saner calling conventions, fix double mntput() in nfs
btrfs: fix double mntput() in mount_subvol()
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
random: Fix handing of arch_get_random_long in get_random_bytes()
x86: Call stop_machine_text_poke() on all CPUs
x86, ioapic: Only print ioapic debug information for IRQs belonging to an ioapic chip
x86/mrst: Avoid reporting wrong nmi status
x86/mrst: Add support for Penwell clock calibration
x86/apic: Allow use of lapic timer early calibration result
x86/apic: Do not clear nr_irqs_gsi if no legacy irqs
x86/platform: Add a wallclock_init func to x86_platforms ops
x86/mce: Make mce_chrdev_ops 'static const'
Randy Dunlap reports that the ex131x driver doesn't build when CONFIG_PM_SLEEP is not enabled.
This bug was introduced when moving code around to remove some forward declarations earlier, the #endif part of #ifdef CONFIG_PM_SLEEP was not moved at the same time. Now fixed by moving it to its proper place.
Reported-by: Randy Dunlap <[email protected]>
Signed-off-by: Mark Einon <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
As is probably painfully obvious, I don't have time to be a cgroups
maintainer. Rather than have me continue to hope that I'll magically
find more spare time, instead Tejun has kindly agreed to take over the
role, along with Li Zefan.
-tj: added cgroup tree URL to MAINTAINERS file
Signed-off-by: Paul Menage <[email protected]>
Acked-by: Li Zefan <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
LKML-Reference: <[email protected]>
Commit 2aede851dd
(PM / Hibernate: Freeze kernel threads after preallocating memory)
postponed the freezing of kernel threads to after preallocating memory
for hibernation. But while doing that, the hibernation test TEST_FREEZER
and the test mode HIBERNATION_TESTPROC were not moved accordingly.
As a result, when using these test modes, it only goes upto the freezing of
userspace and exits, when in fact it should go till the complete end of task
freezing stage, namely the freezing of kernel threads as well.
So, move these points of exit to appropriate places so that freezing of
kernel threads is also tested while using these test harnesses.
Signed-off-by: Srivatsa S. Bhat <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
commit f39925dbde (ipv4: Cache learned redirect information in
inetpeer.) introduced a regression in ICMP redirect handling.
It assumed ipv4_dst_check() would be called because all possible routes
were attached to the inetpeer we modify in ip_rt_redirect(), but thats
not true.
commit 7cc9150ebe (route: fix ICMP redirect validation) tried to fix
this but solution was not complete. (It fixed only one route)
So we must lookup existing routes (including different TOS values) and
call check_peer_redir() on them.
Reported-by: Ivan Zahariev <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
CC: Flavio Leitner <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
