Commit 06222e491e got the if wrong so that
it always evaluates as true. This is semantically harmless, but makes
SEEK_CUR and SEEK_SET needlessly query the server.
Rewrite the if to explicitly enumerate the cases we DO need a valid i_size
to make this code less fragile.
Reported-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
We have been using i_lock to protect all kinds of data structures in the
ceph_inode_info struct, including lists of inodes that we need to iterate
over while avoiding races with inode destruction. That requires grabbing
a reference to the inode with the list lock protected, but igrab() now
takes i_lock to check the inode flags.
Changing the list lock ordering would be a painful process.
However, using a ceph-specific i_ceph_lock in the ceph inode instead of
i_lock is a simple mechanical change and avoids the ordering constraints
imposed by igrab().
Reported-by: Amon Ott <a.ott@m-privacy.de>
Signed-off-by: Sage Weil <sage@newdream.net>
This doesn't interact with resizing well, since it doesn't set the
size of the device to the size at the snapshot. It's also an expensive
operation to be synchronous. Rollback can still be done with the
userspace rbd tool.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
ceph_osd_request struct allocates a 40-byte buffer for object names.
RBD image names can be up to 96 chars long (100 with the .rbd suffix),
which results in the object name for the image being truncated, and a
subsequent map failure.
Increase the oid buffer in request messages, in order to avoid the
truncation.
Signed-off-by: Stratos Psomadakis <psomas@grnet.gr>
Signed-off-by: Sage Weil <sage@newdream.net>
Set up d_fsdata on the root dentry. This fixes a NULL pointer dereference
in ceph_d_prune on umount. It also means we can eventually strip out all
of the conditional checks on d_fsdata because it is now set unconditionally
(prior to setting up the d_ops).
Fix the ceph_d_prune debug print while we're here.
Signed-off-by: Sage Weil <sage@newdream.net>
If we queue a work item that calls iput(), make sure we ihold() before
attempting to queue work. Otherwise our queued work might miraculously run
before we notice the queue_work() succeeded and call ihold(), allowing the
inode to be destroyed.
That is, instead of
if (queue_work(...))
ihold();
we need to do
ihold();
if (!queue_work(...))
iput();
Reported-by: Amon Ott <a.ott@m-privacy.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Quiet the sparse noise:
warning: symbol 'create_fs_client' was not declared. Should it be static?
warning: symbol 'destroy_fs_client' was not declared. Should it be static?
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Sage Weil <sage@newdream.net>
ceph-devel@vger.kernel.org
Signed-off-by: Sage Weil <sage@newdream.net>
Quiet the following sparse noise:
warning: symbol 'get_nonsnap_parent' was not declared. Should it be static?
warning: symbol 'done_closing_sessions' was not declared. Should it be static?
Local functions don't need external visability. Make them static.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Sage Weil <sage@newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
We used to use a flag on the directory inode to track whether the dcache
contents for a directory were a complete cached copy. Switch to a dentry
flag CEPH_D_COMPLETE that is safely updated by ->d_prune().
Signed-off-by: Sage Weil <sage@newdream.net>
When the VFS prunes a dentry from the cache, clear the D_COMPLETE flag
on the parent dentry. Do this for the live and snapshotted namespaces. Do
not bother for the .snap dir contents, since we do not cache that.
Signed-off-by: Sage Weil <sage@newdream.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock:
hwspinlock: add MAINTAINERS entries
hwspinlock/omap: omap_hwspinlock_remove should be __devexit
hwspinlock/u8500: add hwspinlock driver
hwspinlock/core: register a bank of hwspinlocks in a single API call
hwspinlock/core: remove stubs for register/unregister
hwspinlock/core: use a mutex to protect the radix tree
hwspinlock/core/omap: fix id issues on multiple hwspinlock devices
hwspinlock/omap: simplify allocation scheme
hwspinlock/core: simplify 'owner' handling
hwspinlock/core: simplify Kconfig
Fix up trivial conflicts (addition of omap_hwspinlock_pdata, removal of
omap_spinlock_latency) in arch/arm/mach-omap2/hwspinlock.c
Also, do an "evil merge" to fix a compile error in omap_hsmmc.c which
for some reason was reported in the same email thread as the "please
pull hwspinlock changes".
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
Revert "HID: multitouch: decide if hid-multitouch needs to handle mt devices"
HID: drivers/hid/hid-roccat.c: eliminate a null pointer dereference
HID: hid-apple: add device ID of another wireless aluminium
HID: Add device IDs for Macbook Pro 8 keyboards
This reverts commit 144060fee0.
It causes a resume regression for Andi on his Acer Aspire 1830T post
3.1. The screen just stays black after wakeup.
Also, it really looks like the wrong way to suspend and resume perf
events: I think they should be done as part of the CPU suspend and
resume, rather than as a notifier that does smp_call_function().
Reported-by: Andi Kleen <andi@firstfloor.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac: (21 commits)
MAINTAINERS: add an entry for Edac Sandy Bridge driver
edac: tag sb_edac as EXPERIMENTAL, as it requires more testing
EDAC: Fix incorrect edac mode reporting in sb_edac
edac: sb_edac: Add it to the building system
edac: Add an experimental new driver to support Sandy Bridge CPU's
i7300_edac: Fix error cleanup logic
i7core_edac: Initialize memory name with cpu, channel, bank
i7core_edac: Fix compilation on 32 bits arch
i7core_edac: scrubbing fixups
EDAC: Correct Kconfig dependencies
i7core_edac: return -ENODEV if no MC is found
i7core_edac: use edac's own way to print errors
MAINTAINERS: remove dropped edac_mce.* from the file
i7core_edac: Drop the edac_mce facility
x86, MCE: Use notifier chain only for MCE decoding
EDAC i7core: Use mce socketid for better compatibility
i7core_edac: Don't enable memory scrubbing for Xeon 35xx
i7core_edac: Add scrubbing support
edac: Move edac main structs to include/linux/edac.h
i7core_edac: Fix oops when trying to inject errors
...
* 'misc-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
MAINTAINERS: Update entry for IA64
[IA64] gpio: GENERIC_GPIO default must be n
[IA64[ add CONFIG_NET_VENDOR_INTEL=y to default config files where needed
[IA64] agp/hp-agp: Allow binding user memory to the AGP GART
[IA64] sn2: add missing put_cpu()
Says Andrew:
"60 patches. That's good enough for -rc1 I guess. I have quite a lot
of detritus to be rechecked, work through maintainers, etc.
- most of the remains of MM
- rtc
- various misc
- cgroups
- memcg
- cpusets
- procfs
- ipc
- rapidio
- sysctl
- pps
- w1
- drivers/misc
- aio"
* akpm: (60 commits)
memcg: replace ss->id_lock with a rwlock
aio: allocate kiocbs in batches
drivers/misc/vmw_balloon.c: fix typo in code comment
drivers/misc/vmw_balloon.c: determine page allocation flag can_sleep outside loop
w1: disable irqs in critical section
drivers/w1/w1_int.c: multiple masters used same init_name
drivers/power/ds2780_battery.c: fix deadlock upon insertion and removal
drivers/power/ds2780_battery.c: add a nolock function to w1 interface
drivers/power/ds2780_battery.c: create central point for calling w1 interface
w1: ds2760 and ds2780, use ida for id and ida_simple_get() to get it
pps gpio client: add missing dependency
pps: new client driver using GPIO
pps: default echo function
include/linux/dma-mapping.h: add dma_zalloc_coherent()
sysctl: make CONFIG_SYSCTL_SYSCALL default to n
sysctl: add support for poll()
RapidIO: documentation update
drivers/net/rionet.c: fix ethernet address macros for LE platforms
RapidIO: fix potential null deref in rio_setup_device()
RapidIO: add mport driver for Tsi721 bridge
...
While back-porting Johannes Weiner's patch "mm: memcg-aware global
reclaim" for an internal effort, we noticed a significant performance
regression during page-reclaim heavy workloads due to high contention of
the ss->id_lock. This lock protects idr map, and serializes calls to
idr_get_next() in css_get_next() (which is used during the memcg hierarchy
walk).
Since idr_get_next() is just doing a look up, we need only serialize it
with respect to idr_remove()/idr_get_new(). By making the ss->id_lock a
rwlock, contention is greatly reduced and performance improves.
Tested: cat a 256m file from a ramdisk in a 128m container 50 times on
each core (one file + container per core) in parallel on a NUMA machine.
Result is the time for the test to complete in 1 of the containers.
Both kernels included Johannes' memcg-aware global reclaim patches.
Before rwlock patch: 1710.778s
After rwlock patch: 152.227s
Signed-off-by: Andrew Bresticker <abrestic@google.com>
Cc: Paul Menage <menage@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In testing aio on a fast storage device, I found that the context lock
takes up a fair amount of cpu time in the I/O submission path. The reason
is that we take it for every I/O submitted (see __aio_get_req). Since we
know how many I/Os are passed to io_submit, we can preallocate the kiocbs
in batches, reducing the number of times we take and release the lock.
In my testing, I was able to reduce the amount of time spent in
_raw_spin_lock_irq by .56% (average of 3 runs). The command I used to
test this was:
aio-stress -O -o 2 -o 3 -r 8 -d 128 -b 32 -i 32 -s 16384 <dev>
I also tested the patch with various numbers of events passed to
io_submit, and I ran the xfstests aio group of tests to ensure I didn't
break anything.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Daniel Ehrenberg <dehrenberg@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In vmballoon_reserve_page(), flags has been passed from the callee
function (vmballoon_inflate here). So, we can determine can_sleep outside
the loop.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Interrupting w1_delay() in w1_read_bit() results in missing the low level
on the w1 line and receiving "1" instead of "0".
Add local_irq_save()/local_irq_restore() around the critical section
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adds a nolock function to the w1 interface to avoid locking the
mutex if needed.
Signed-off-by: Clifton Barnes <cabarnes@indesign-llc.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Straightforward. As an aside, the ida_init calls are not needed as far as
I can see needed. (DEFINE_IDA does the same already).
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Clifton Barnes <cabarnes@indesign-llc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add "depends on GENERIC_HARDIRQS" to avoid compile breakage on s390:
drivers/built-in.o: In function `pps_gpio_remove':
linux-next/drivers/pps/clients/pps-gpio.c:189: undefined reference to `free_irq'
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Nuss <jamesnuss@nanometrics.ca>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This client driver allows you to use a GPIO pin as a source for PPS
signals. Platform data [1] are used to specify the GPIO pin number,
label, assert event edge type, and whether clear events are captured.
This driver is based on the work by Ricardo Martins who submitted an
initial implementation [2] of a PPS IRQ client driver to the linuxpps
mailing-list on Dec 3 2010.
[1] include/linux/pps-gpio.h
[2] http://ml.enneenne.com/pipermail/linuxpps/2010-December/004155.html
[akpm@linux-foundation.org: remove unneeded cast of void*]
Signed-off-by: James Nuss <jamesnuss@nanometrics.ca>
Cc: Ricardo Martins <rasm@fe.up.pt>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Ricardo Martins <rasm@fe.up.pt>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A default echo function has been provided so it is no longer an error when
you specify PPS_ECHOASSERT or PPS_ECHOCLEAR without an explicit echo
function. This allows some code re-use and also makes it easier to write
client drivers since the default echo function does not normally need to
change.
Signed-off-by: James Nuss <jamesnuss@nanometrics.ca>
Reviewed-by: Ben Gardiner <bengardiner@nanometrics.ca>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Cc: Ricardo Martins <rasm@fe.up.pt>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lots of driver code does a dma_alloc_coherent() and then zeroes out the
memory with a memset. Make it easy for them.
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I tried to send a patch to remove it, Andi told me we still need to
keep compabitlies for old libc, so we can't remove this completely. Then
just make it default to n and remove the doc from
feature-removal-schedule.txt.
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adding support for poll() in sysctl fs allows userspace to receive
notifications of changes in sysctl entries. This adds a infrastructure to
allow files in sysctl fs to be pollable and implements it for hostname and
domainname.
[akpm@linux-foundation.org: s/declare/define/ for definitions]
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Greg KH <gregkh@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update rapidio.txt to reflect changes from recent patch.
See http://marc.info/?l=linux-kernel&m=131285620113589&w=2 for details.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Liu Gang <Gang.Liu@freescale.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify Ethernet addess macros to be compatible with BE/LE platforms
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Chul Kim <chul.kim@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: <stable@kernel.org> [2.6.39+]
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "goto cleanup" path can deference "rswitch" when it is NULL.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Chul Kim <chul.kim@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add RapidIO mport driver for IDT TSI721 PCI Express-to-SRIO bridge device.
The driver provides full set of callback functions defined for mport
devices in RapidIO subsystem. It also is compatible with current version
of RIONET driver (Ethernet over RapidIO messaging services).
This patch is applicable to kernel versions starting from 2.6.39.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Chul Kim <chul.kim@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "struct rio_mport" contains a member of master port I/O memory
resource structure "struct resource iores". This resource will be read
from device tree and be used for rapidio R/W transaction memory space.
Rapidio requests the port I/O memory resource under the root resource
"iomem_resource".
struct rio_mport *port;
port = kzalloc(sizeof(struct rio_mport), GFP_KERNEL);
request_resource(&iomem_resource, &port->iores);
When port failed to initialize, allocated "rio_mport" structure memory
will be freed, and the port I/O memory resource structure pointer
"&port->iores" will be invalid. If other requests resource under
"iomem_resource", "&port->iores" node may be operated in the child
resources list and this will cause the system to crash.
So the requested port I/O memory resource should be released before
freeing allocated "rio_mport" structure.
Signed-off-by: Liu Gang <Gang.Liu@freescale.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The discovered bit in PGCCSR register indicates if the device has been
discovered by system host. In Rapidio systems, some agent devices can also
be master devices. They can issue requests into the system.
Signed-off-by: Liu Gang <Gang.Liu@freescale.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Expand root=PARTUUID=UUID syntax to support selecting a root partition by
integer offset from a known, unique partition. This approach provides
similar properties to specifying a device and partition number, but using
the UUID as the unique path prior to evaluating the offset.
For example,
root=PARTUUID=99DE9194-FC15-4223-9192-FC243948F88B/PARTNROFF=1
selects the partition with UUID 99DE.. then select the next
partition.
This change is motivated by a particular usecase in Chromium OS where the
bootloader can easily determine what partition it is on (by UUID) but
doesn't perform general partition table walking.
That said, support for this model provides a direct mechanism for the user
to modify the root partition to boot without specifically needing to
extract each UUID or update the bootloader explicitly when the root
partition UUID is changed (if it is recreated to be larger, for instance).
Pinning to a /boot-style partition UUID allows the arbitrary root
partition reconfiguration/modifications with slightly less ambiguity than
just [dev][partition] and less stringency than the specific root partition
UUID.
[sfr@canb.auug.org.au: fix init sections warning]
Signed-off-by: Will Drewry <wad@chromium.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For the sysvsem undo, each task struct contains a sysv_sem structure with
a pointer to the undo information.
This pointer is only necessary if sysvipc is enabled - thus the pointer
can be made conditional on CONFIG_SYSVIPC.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/sem.h contains several structures that are only used within
ipc/sem.c.
The patch moves them into ipc/sem.c - there is no need to expose the
structures to the whole kernel.
No functional changes, only whitespace cleanups and 80-char per line
fixes.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
semtimedop() does not handle spurious wakeups, it returns -EINTR to user
space. Most other schedule() users would just loop and not return to user
space. The patch adds such a loop to semtimedop()
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_semtimedop() may return -EIDRM although the semaphore operation
completed successfully:
thread 1: thread 2:
semtimedop(), sleeps
semop():
* acquires sem_lock()
semtimedop() woken up due to timeout
sem_lock() loops
* notices that thread 2 could be completed.
* performs the operations that thread 2 is sleeping on.
* marks the semaphore operation as IN_WAKEUP
* drops sem_lock(), does wakeup, sets return code to 0
* thread delayed due to interrupt, whatever
* returns to user space
* thread still delayed
semctl(IPC_RMID)
* acquires sem_lock()
* ipc_rmid(), ipcp->deleted=1
* drops sem_lock()
* thread finally continues - but seem_lock()
now fails due to ipcp->deleted == 1
* returns -EIDRM instead of 0
The fix is trivial: Always use the return code in queue.status.
In real world, the race probably doesn't matter:
If the semaphore array is destroyed, the app is probably not interested
if the last operation succeeded or was already cancelled.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
