* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300:
Separate out the proc- and unit-specific header directories from the general
Move arch headers from include/asm-mn10300/ to arch/mn10300/include/asm/.
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (27 commits)
xsysace: Fix dereferencing of cf_id after hd_driveid removal
at91_ide: turn on PIO 6 support
at91_ide: remove unused ide_mm_{outb,inb}
ide-cd: reverse NOT_READY sense key logic
ide: refactor tf_read() method
ide: refactor tf_load() method
ide: call write_devctl() method from tf_read() method
ide: move common code out of tf_load() method
ide: simplify 'struct ide_taskfile'
ide: replace IDE_TFLAG_* flags by IDE_VALID_*
ide-cd: fix intendation in cdrom_decode_status()
ide-cd: unify handling of fs and pc requests in cdrom_decode_status()
ide-cd: convert cdrom_decode_status() to use switch statements
ide-cd: update debugging support
ide-cd: respect REQ_QUIET for fs requests in cdrom_decode_status()
ide: remove unused #include <linux/version.h>
tx4939ide: Fix tx4939ide_{in,out}put_data_swap argument
tx493[89]ide: Remove big endian version of tx493[89]ide_tf_{load,read}
ide-cd: carve out an ide_cd_breathe()-helper for fs write requests
ide-cd: move status checking into the IRQ handler
...
asm-frv/pgtable.h could just #include <asm-generic/pgtable.h> in NOMMU mode
rather than #defining macros for lazy MMU and CPU stuff.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: consolidate documents
blktrace: pass the right pointer to kfree()
tracing/syscalls: use a dedicated file header
tracing: append a comma to INIT_FTRACE_GRAPH
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: do not count frozen tasks toward load
sched: refresh MAINTAINERS entry
sched: Print sched_group::__cpu_power in sched_domain_debug
cpuacct: add per-cgroup utime/stime statistics
posixtimers, sched: Fix posix clock monotonicity
sched_rt: don't allocate cpumask in fastpath
cpuacct: make cpuacct hierarchy walk in cpuacct_charge() safe when rcupreempt is used -v2
Since the whole point of try_then_request_module is to retry
the operation after a module has been loaded, we must wait for
the module to fully load.
Otherwise all sort of things start breaking, e.g., you won't
be able to read your encrypted disks on the first attempt.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Tested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Freezing tasks via the cgroup freezer causes the load average to climb
because the freezer's current implementation puts frozen tasks in
uninterruptible sleep (D state).
Some applications which perform job-scheduling functions consult the
load average when making decisions. If a cgroup is frozen, the load
average does not provide a useful measure of the system's utilization
to such applications. This is especially inconvenient if the job
scheduler employs the cgroup freezer as a mechanism for preempting low
priority jobs. Contrast this with using SIGSTOP for the same purpose:
the stopped tasks do not count toward system load.
Change task_contributes_to_load() to return false if the task is
frozen. This results in /proc/loadavg behavior that better meets
users' expectations.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Tested-by: Nigel Cunningham <nigel@tuxonice.net>
Cc: <stable@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: linux-pm@lists.linux-foundation.org
Cc: Matt Helsley <matthltc@us.ibm.com>
LKML-Reference: <20090408194512.47a99b95@manatee.lan>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix build warnings and possibe compat misbehavior on IA64
Building a kernel on ia64 might trigger these ugly build warnings:
CC arch/ia64/ia32/sys_ia32.o
In file included from arch/ia64/ia32/sys_ia32.c:55:
arch/ia64/ia32/ia32priv.h:290:1: warning: "elf_check_arch" redefined
In file included from include/linux/elf.h:7,
from include/linux/module.h:14,
from include/linux/ftrace.h:8,
from include/linux/syscalls.h:68,
from arch/ia64/ia32/sys_ia32.c:18:
arch/ia64/include/asm/elf.h:19:1: warning: this is the location of the previous definition
[...]
sys_ia32.c includes linux/syscalls.h which in turn includes linux/ftrace.h
to import the syscalls tracing prototypes.
But including ftrace.h can pull too much things for a low level file,
especially on ia64 where the ia32 private headers conflict with higher
level headers.
Now we isolate the syscall tracing headers in their own lightweight file.
Reported-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Michael Davidson <md@google.com>
LKML-Reference: <20090408184058.GB6017@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
igb: remove sysfs entry that was used to set the number of vfs
igbvf: add new driver to support 82576 virtual functions
drivers/net/eql.c: Fix a dev leakage.
niu: Fix unused variable warning.
r6040: set MODULE_VERSION
bnx2: Don't use reserved names
FEC driver: add missing #endif
niu: Fix error handling
mv643xx_eth: don't reset the rx coal timer on interface up
smsc911x: correct debugging message on mii read timeout
ethoc: fix library build errors
netfilter: ctnetlink: fix regression in expectation handling
netfilter: fix selection of "LED" target in netfilter
netfilter: ip6tables regression fix
Prepare for full barrier implementation: first remove the restricted support.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
x86 ACPI: Add support for Always Running APIC timer
ACPI x86: Make aperf/mperf MSR access in acpi_cpufreq read_only
ACPI x86: Cleanup acpi_cpufreq structures related to aperf/mperf
ACPICA: delete check for AML access to port 0x81-83
ACPI: WMI: use .notify method instead of installing handler directly
sony-laptop: use .notify method instead of installing handler directly
panasonic-laptop: use .notify method instead of installing handler directly
fujitsu-laptop: use .notify method instead of installing hotkey handler directly
fujitsu-laptop: use .notify method instead of installing handler directly
ACPI: video: use .notify method instead of installing handler directly
ACPI: thermal: use .notify method instead of installing handler directly
ACPI battery: fix async boot oops
ACPI: delete acpi_device.g_list
NULL noise: drivers/platform/x86/panasonic-laptop.c
ACPI: cpufreq: remove dupilcated #include
ACPI: Adjust Kelvin offset to match local implementation
ACPI: convert acpi_device_lock spinlock to mutex
Thou shalt remember to use 'git add' or errors shall be visited on your
downloads and there shall be wrath from on list and much gnashing of teeth.
Thou shalt remember to use git status or there shall be catcalls and much
embarrasment shall come to pass.
Signed-off-by: Alan "I'm hiding" Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simplify tf_read() method, making it deal only with 'struct ide_taskfile' and
the validity flags that the upper layer passes, and factoring out the code that
deals with the high order bytes into ide_tf_readback() to be called from the
only two functions interested, ide_complete_cmd() and ide_dump_sector().
This should stop the needless code duplication in this method and so make
it about twice smaller than it was; along with simplifying the setup for
the method call, this should save both time and space...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Simplify tf_load() method, making it deal only with 'struct ide_taskfile' and
the validity flags that the upper layer passes, and moving the code that deals
with the high order bytes into the only function interested, do_rw_taskfile().
This should stop the needless code duplication in this method and so make
it about twice smaller than it was; along with simplifying the setup for the
method call, this should save both time and space...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Make 'struct ide_taskfile' cover only 8 register values and thus put two such
fields ('tf' and 'hob') into 'struct ide_cmd', dropping unnecessary 'tf_array'
field from it.
This required changing the prototype of ide_get_lba_addr() and ide_tf_dump().
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[bart: fix setting of ATA_LBA bit for LBA48 commands in __ide_do_rw_disk()]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Replace IDE_TFLAG_{IN|OUT}_* flags meaning to the taskfile register validity on
input/output by the IDE_VALID_* flags and introduce 4 symmetric 8-bit register
validity indicator subfields, 'valid.{input/output}.{tf|hob}', into the 'struct
ide_cmd' instead of using the 'tf_flags' field for that purpose (this field can
then be turned from 32-bit into 8-bit one).
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Impact: dont break future extensions of INIT_TASK
While not a problem right now, due to lack of a comma, build fails if
elements are appended to INIT_TASK() macro in development code:
arch/x86/kernel/init_task.c:33: error: request for member `XXXXXXXXXX' in something not a structure or union
arch/x86/kernel/init_task.c:33: error: initializer element is not constant
arch/x86/kernel/init_task.c:33: error: (near initialization for `init_task.ret_stack')
make[1]: *** [arch/x86/kernel/init_task.o] Error 1
make: *** [arch/x86/kernel] Error 2
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: srostedt@redhat.com
LKML-Reference: <200904080505.n3855hcn017109@www262.sakura.ne.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'core/softlockup' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
softlockup: make DETECT_HUNG_TASK default depend on DETECT_SOFTLOCKUP
softlockup: move 'one' to the softlockup section in sysctl.c
softlockup: ensure the task has been switched out once
softlockup: remove timestamp checking from hung_task
softlockup: convert read_lock in hung_task to rcu_read_lock
softlockup: check all tasks in hung_task
softlockup: remove unused definition for spawn_softlockup_task
softlockup: fix potential race in hung_task when resetting timeout
softlockup: fix to allow compiling with !DETECT_HUNG_TASK
softlockup: decouple hung tasks check from softlockup detection
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y
branch tracer: Fix for enabling branch profiling makes sparse unusable
ftrace: Correct a text align for event format output
Update /debug/tracing/README
tracing/ftrace: alloc the started cpumask for the trace file
tracing, x86: remove duplicated #include
ftrace: Add check of sched_stopped for probe_sched_wakeup
function-graph: add proper initialization for init task
tracing/ftrace: fix missing include string.h
tracing: fix incorrect return type of ns2usecs()
tracing: remove CALLER_ADDR2 from wakeup tracer
blktrace: fix pdu_len when tracing packet command requests
blktrace: small cleanup in blk_msg_write()
blktrace: NUL-terminate user space messages
tracing: move scripts/trace/power.pl to scripts/tracing/power.pl
* 'irq/threaded' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: fix devres.o build for GENERIC_HARDIRQS=n
genirq: provide old request_irq() for CONFIG_GENERIC_HARDIRQ=n
genirq: threaded irq handlers review fixups
genirq: add support for threaded interrupts to devres
genirq: add threaded interrupt handler support
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: pci_slot: grab refcount on slot's bus
PCI Hotplug: acpiphp: grab refcount on p2p subordinate bus
PCI: allow PCI core hotplug to remove PCI root bus
PCI: Fix oops in pci_vpd_truncate
PCI: don't corrupt enable_cnt when doing manual resource alignment
PCI: annotate pci_rescan_bus as __ref, not __devinit
PCI-IOV: fix missing kernel-doc
PCI: Setup disabled bridges even if buses are added
PCI: SR-IOV quirk for Intel 82576 NIC
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
loop: mutex already unlocked in loop_clr_fd()
cfq-iosched: don't let idling interfere with plugging
block: remove unused REQ_UNPLUG
cfq-iosched: kill two unused cfqq flags
cfq-iosched: change dispatch logic to deal with single requests at the time
mflash: initial support
cciss: change to discover first memory BAR
cciss: kernel scan thread for MSA2012
cciss: fix residual count for block pc requests
block: fix inconsistency in I/O stat accounting code
block: elevator quiescing helpers
The code that enables branch tracing for all (non-constant) branches
plays games with the preprocessor and #define's the C 'if ()' construct
to do tracing.
That's all fine, but it fails for some unusual but valid C code that is
sometimes used in macros, notably by the intel-iommu code:
if (i=drhd->iommu, drhd->ignored) ..
because now the preprocessor complains about multiple arguments to the
'if' macro.
So make the macro expansion of this particularly horrid trick use
varargs, and handle the case of comma-expressions in if-statements. Use
another macro to do it cleanly in just one place.
This replaces a patch by David (and acked by Steven) that did this all
inside that one already-too-horrid macro.
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'i2c-for-2630-v2' of git://aeryn.fluff.org.uk/bjdooks/linux:
i2c: imx: Make disable_delay a per-device variable
i2c: xtensa s6000 i2c driver
powerpc/85xx: i2c-mpc: use new I2C bindings for the Socates board
i2c: i2c-mpc: make I2C bus speed configurable
i2c: i2c-mpc: use dev based printout function
i2c: i2c-mpc: various coding style fixes
i2c: imx: Add missing request_mem_region in probe()
i2c: i2c-s3c2410: Initialise Samsung I2C controller early
i2c-s3c2410: Simplify bus frequency calculation
i2c-s3c2410: sda_delay should be in ns, not clock ticks
i2c: iMX/MXC support
PCI parallel port devices can IRQ share so we should stop them hogging
the line and making a mess on modern PC systems. We know the sharing
side works as the PCMCIA driver has shared the parallel port IRQ for
some time.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(akpm: queued pending confirmation of the new major number)
[randy.dunlap@oracle.com: select SERIAL_CORE]
Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tty_driver_kref_get() should be static inline and not extern inline
(the latter even changed it's semantics in gcc >= 4.3).
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After a review of user's feedback for finding out other compatibility
issues, I found nilfs improperly initializes timestamps in inode;
CURRENT_TIME was used there instead of CURRENT_TIME_SEC even though nilfs
didn't have nanosecond timestamps on disk. A few users gave us the report
that the tar program sometimes failed to expand symbolic links on nilfs,
and it turned out to be the cause.
Instead of applying the above displacement, I've decided to support
nanosecond timestamps on this occation. Fortunetaly, a needless 64-bit
field was in the nilfs_inode struct, and I found it's available for this
purpose without impact for the users.
So, this will do the enhancement and resolve the tar problem.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The former versions didn't have extra super blocks. This improves the
weak point by introducing another super block at unused region in tail of
the partition.
This doesn't break disk format compatibility; older versions just ingore
the secondary super block, and new versions just recover it if it doesn't
exist. The partition created by an old mkfs may not have unused region,
but in that case, the secondary super block will not be added.
This doesn't make more redundant copies of the super block; it is a future
work.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nilfs creates checkpoints even for garbage collection or metadata updates
such as checkpoint mode change. So, user often sees checkpoints created
only by such internal operations.
This is inconvenient in some situations. For example, application that
monitors checkpoints and changes them to snapshots, will fall into an
infinite loop because it cannot distinguish internally created
checkpoints.
This patch solves this sort of problem by adding a flag to checkpoint for
identification.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The sketch file is a file to mark checkpoints with user data. It was
experimentally introduced in the original implementation, and now
obsolete. The file was handled differently with regular files; the file
size got truncated when a checkpoint was created.
This stops the special treatment and will treat it as a regular file.
Most users are not affected because mkfs.nilfs2 no longer makes this file.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a new argument to the nilfs_sustat structure.
The extended field allows to delete volatile active state of segments,
which was needed to protect freshly-created segments from garbage
collection but has confused code dealing with segments. This
extension alleviates the mess and gives room for further
simplifications.
The volatile active flag is not persistent, so it's eliminable on this
occasion without affecting compatibility other than the ioctl change.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes compat code from the nilfs ioctls and applies the same
function for both .ioctl and .compat_ioctl file operations.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nilfs ioctl had structures not having fixed sized types such as:
struct nilfs_argv {
void *v_base;
size_t v_nmembs;
size_t v_size;
int v_index;
int v_flags;
};
Further, some of them are wrongly aligned:
e.g.
struct nilfs_cpmode {
__u64 cm_cno;
int cm_mode;
};
The size of wrongly aligned structures varies depending on
architectures, and it breaks the identity of ioctl commands, which
leads to arch dependent errors.
Previously, these are compensated by using compat_ioctl.
This fixes these problems and allows removal of compat ioctl.
Since this will change sizes of those structures, binary compatibility
for the past utilities will once break; new utilities have to be used
instead. However, it would be helpful to avoid platform dependent
problems in the long term.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes NILFS_IOCTL_TIMEDWAIT command from ioctl interface along
with the related flags and wait queue.
The command is terrible because it just sleeps in the ioctl. I prefer
to avoid this by devising means of event polling in userland program.
By reconsidering the userland GC daemon, I found this is possible
without changing behaviour of the daemon and sacrificing efficiency.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a header file which specifies the on-disk format and ioctl
interface of the nilfs2 file system.
Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)
Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Largely inspired from ipc/ipc_sysctl.c. This patch isolates the mqueue
sysctl stuff in its own file.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.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>
Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.
Each ipc ns has a corresponding mqueuefs superblock. When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.
When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.
Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount. Any
usage of mq_open() and friends will work with the acting task's ipc
namespace. Any actions through the VFS will work with the mqueuefs in
which the file was created. So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".
If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.
To make this happen, we must protect the ipc reference count when
a) a task exits and drops its ipcns->count, since it might be dropping
it to 0 and freeing the ipcns
b) a task accesses the ipcns through its mqueuefs interface, since it
bumps the ipcns refcount and might race with the last task in the ipcns
exiting.
So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.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>
Linus Torvalds
David Howells
Herbert Xu
Nathan Lynch
Frederic Weisbecker
Mikulas Patocka
Alan Cox
David S. Miller
Sergei Shtylyov
Tetsuo Handa
Len Brown
Christian Pellegrin
Adrian Bunk
Ryusuke Konishi
Koji Sato
Yang Hongyang
Serge E. Hallyn