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>
Move mqueue vfsmount plus a few tunables into the ipc_namespace struct.
The CONFIG_IPC_NS boolean and the ipc_namespace struct will serve both the
posix message queue namespaces and the SYSV ipc namespaces.
The sysctl code will be fixed separately in patch 3. After just this
patch, making a change to posix mqueue tunables always changes the values
in the initial ipc namespace.
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>
Add disable_kprobe() and enable_kprobe() to disable/enable kprobes
temporarily.
disable_kprobe() asynchronously disables probe handlers of specified
kprobe. So, after calling it, some handlers can be called at a while.
enable_kprobe() enables specified kprobe.
aggr_pre_handler and aggr_post_handler check disabled probes. On the
other hand aggr_break_handler and aggr_fault_handler don't check it
because these handlers will be called while executing pre or post handlers
and usually those help error handling.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some SPI controllers have restrictions on DMAable buffers alignemt.
Currently if the buffer supplied by protocol driver is not properly
aligned, the controller silently performs transfer in PIO mode. Addition
of dma_alignment field to spi_master allows protocol drivers to perform
proper alignment.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add /proc entries to give the admin the ability to control the minimum and
maximum number of pdflush threads. This allows finer control of pdflush
on both large and small machines.
The rationale is simply one size does not fit all. Admins on large and/or
small systems may want to tune the min/max pdflush thread count to best
suit their needs. Right now the min/max is hardcoded to 2/8. While
probably a fair estimate for smaller machines, large machines with large
numbers of CPUs and large numbers of filesystems/block devices may benefit
from larger numbers of threads working on different block devices.
Even if the background flushing algorithm is radically changed, it is
still likely that multiple threads will be involved and admins would still
desire finer control on the min/max other than to have to recompile the
kernel.
The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and
'/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions.
The minimum value for nr_pdflush_threads_min is 1 and the maximum value is
the current value of nr_pdflush_threads_max. This minimum is required
since additional thread creation is performed in a pdflush thread itself.
The minimum value for nr_pdflush_threads_max is the current value of
nr_pdflush_threads_min and the maximum value can be 1000.
Documentation/sysctl/vm.txt is also updated.
[akpm@linux-foundation.org: fix comment, fix whitespace, use __read_mostly]
Signed-off-by: Peter W Morreale <pmorreale@novell.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (28 commits)
powerpc: Fix oops when loading modules
powerpc: Wire up preadv and pwritev
powerpc/ftrace: Fix printf format warning
powerpc/ftrace: Fix #if that should be #ifdef
powerpc: Fix ptrace compat wrapper for FPU register access
powerpc: Print information about mapping hw irqs to virtual irqs
powerpc: Correct dependency of KEXEC
powerpc: Disable VSX or current process in giveup_fpu/altivec
powerpc/pseries: Enable relay in pseries_defconfig
powerpc/pseries: Fix ibm,client-architecture comment
powerpc/pseries: Scan for all events in rtasd
powerpc/pseries: Add dispatch dispersion statistics
powerpc: Clean up some prom printouts
powerpc: Print progress of ibm,client-architecture method
powerpc: Remove duplicated #include's
powerpc/pmac: Fix internal modem IRQ on Wallstreet PowerBook
powerpc/wdrtas: Update wdrtas_get_interval to use rtas_data_buf
fsl-diu-fb: Pass the proper device for dma mapping routines
powerpc/pq2fads: Update device tree for use with device-tree-aware u-boot.
cpm_uart: Disable CPM udbg when re-initing CPM uart, even if not the console.
...
Add support to the SQ-905 driver to pass back to user space the
sensor orientation information obtained from the camera during init.
Modifies gspca and the videodev2.h header to create the necessary
API.
[mchehab@redhat.com: Changed "Output is" to "Frames are" at the comments, as suggested at LMML]
Signed-off-by: Adam Baker <linux@baker-net.org.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* git://git.infradead.org/mtd-2.6: (53 commits)
[MTD] struct device - replace bus_id with dev_name(), dev_set_name()
[MTD] [NOR] Fixup for Numonyx M29W128 chips
[MTD] mtdpart: Make ecc_stats more realistic.
powerpc/85xx: TQM8548: Update DTS file for multi-chip support
powerpc: NAND: FSL UPM: document new bindings
[MTD] [NAND] FSL-UPM: Add wait flags to support board/chip specific delays
[MTD] [NAND] FSL-UPM: add multi chip support
[MTD] [NOR] Add device parent info to physmap_of
[MTD] [NAND] Add support for NAND on the Socrates board
[MTD] [NAND] Add support for 4KiB pages.
[MTD] sysfs support should not depend on CONFIG_PROC_FS
[MTD] [NAND] Add parent info for CAFÉ controller
[MTD] support driver model updates
[MTD] driver model updates (part 2)
[MTD] driver model updates
[MTD] [NAND] move gen_nand's probe function to .devinit.text
[MTD] [MAPS] move sa1100 flash's probe function to .devinit.text
[MTD] fix use after free in register_mtd_blktrans
[MTD] [MAPS] Drop now unused sharpsl-flash map
[MTD] ofpart: Check name property to determine partition nodes.
...
Manually fix trivial conflict in drivers/mtd/maps/Makefile
Fixes:
In file included from drivers/serial/mux.c:37:
include/linux/serial_core.h: In function 'uart_handle_sysrq_char':
include/linux/serial_core.h:467: error: 'struct uart_port' has no member named 'sysrq'
include/linux/serial_core.h:468: error: 'struct uart_port' has no member named 'sysrq'
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This implements basic support for all 843x RS232 devices, but does not
add DMA support. This means that sustained data transfers at high baud
rates may not be possible on multiple ports simultaneously.
Signed-off-by: Shawn Bohrer <shawn.bohrer@ni.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kmemtrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
kmemtrace: trace kfree() calls with NULL or zero-length objects
kmemtrace: small cleanups
kmemtrace: restore original tracing data binary format, improve ABI
kmemtrace: kmemtrace_alloc() must fill type_id
kmemtrace: use tracepoints
kmemtrace, rcu: don't include unnecessary headers, allow kmemtrace w/ tracepoints
kmemtrace, rcu: fix rcupreempt.c data structure dependencies
kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies
kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies
kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_unlzma.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_bunzip2.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_inflate.c
kmemtrace, squashfs: fix slab.h dependency problem in squasfs
kmemtrace, befs: fix slab.h dependency problem
kmemtrace, security: fix linux/key.h header file dependencies
kmemtrace, fs: fix linux/fdtable.h header file dependencies
kmemtrace, fs: uninline simple_transaction_set()
kmemtrace, fs, security: move alloc_secdata() and free_secdata() to linux/security.h
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux: (81 commits)
nfsd41: define nfsd4_set_statp as noop for !CONFIG_NFSD_V4
nfsd41: define NFSD_DRC_SIZE_SHIFT in set_max_drc
nfsd41: Documentation/filesystems/nfs41-server.txt
nfsd41: CREATE_EXCLUSIVE4_1
nfsd41: SUPPATTR_EXCLCREAT attribute
nfsd41: support for 3-word long attribute bitmask
nfsd: dynamically skip encoded fattr bitmap in _nfsd4_verify
nfsd41: pass writable attrs mask to nfsd4_decode_fattr
nfsd41: provide support for minor version 1 at rpc level
nfsd41: control nfsv4.1 svc via /proc/fs/nfsd/versions
nfsd41: add OPEN4_SHARE_ACCESS_WANT nfs4_stateid bmap
nfsd41: access_valid
nfsd41: clientid handling
nfsd41: check encode size for sessions maxresponse cached
nfsd41: stateid handling
nfsd: pass nfsd4_compound_state* to nfs4_preprocess_{state,seq}id_op
nfsd41: destroy_session operation
nfsd41: non-page DRC for solo sequence responses
nfsd41: Add a create session replay cache
nfsd41: create_session operation
...
