This patch fixes some potential multithreading issues, despite only
allowing one process to open the /dev/watchdog device, we can still get
called multiple times at the same time, since a program could be using thread,
or could share the fd after a fork.
This causes 2 potential problems:
1) watchdog_start / open do an unlocked test_n_set / test_n_clear,
if these 2 race, the watchdog could be stopped while the active
bit indicates it is running or visa versa.
2) Most watchdog_dev drivers probably assume that only one
watchdog-op will get called at a time, this is not necessary
true atm.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Rewrite and extend the wrapper code so that we can easily introduce
locking (this to be able to prevent potential multithreading issues).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
While they are registered all our watchdogs now have a valid device object
so we can in turn use that to report problems nicely.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Create the watchdog class and it's associated devices.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Some watchdogs merely trigger external alarms and controls. In a managed
environment this is very useful but we want drivers to be able to figure
out which is which now multiple dogs can be loaded. Thus add an ALARMONLY
feature flag.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
We keep the old /dev/watchdog interface file for the first watchdog via
miscdev. This is basically a cut and paste of the relevant interface code
from the rtc driver layer tweaked for watchdog.
Revised to fix problems noted by Hans de Goede
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
The watchdog_core include file should have been named
watchdog_core.h and not watchdog_dev.h . Correct this.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Some watchdog may need to check if watchdog is ACTIVE or not, for example in
their suspend/resume hooks.
This patch adds this routine and changes the core drivers to use it.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Include the private watchdog_dev.h header to pickup the prototypes for the
watchdog_dev_register/unregister functions.
This quiets the following sparse warnings:
warning: symbol 'watchdog_dev_register' was not declared. Should it be static?
warning: symbol 'watchdog_dev_unregister' was not declared. Should it be static?
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
lglocks and brlocks are currently generated with some complicated macros
in lglock.h. But there's no reason to not just use common utility
functions and put all the data into a common data structure.
In preparation, this patch changes the API to look more like normal
function calls with pointers, not magic macros.
The patch is rather large because I move over all users in one go to keep
it bisectable. This impacts the VFS somewhat in terms of lines changed.
But no actual behaviour change.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
lglocks and brlocks are currently generated with some complicated macros
in lglock.h. But there's no reason to not just use common utility
functions and put all the data into a common data structure.
Since there are at least two users it makes sense to share this code in a
library. This is also easier maintainable than a macro forest.
This will also make it later possible to dynamically allocate lglocks and
also use them in modules (this would both still need some additional, but
now straightforward, code)
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Optimizing the slow paths adds a lot of complexity. If you need to
grab every lock often, you have other problems.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
seeing that "fast" symlinks still get allocation + copy, we might as
well simply switch them to pagecache-based variant of ->follow_link();
just need an appropriate ->readpage() for them...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix kernel-doc warnings in fs/inode.c:
Warning(fs/inode.c:1493): No description found for parameter 'path'
Warning(fs/inode.c:1493): Excess function parameter 'mnt' description in 'touch_atime'
Warning(fs/inode.c:1493): Excess function parameter 'dentry' description in 'touch_atime'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a couple of le32 and le16 used with wrong le..._to_cpu(), plus
idiotic use of le32_to_cpu() on 1-bit bitfield
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ocfs2_block_check is for little-endian contents; if we just want to
its fields converted to host-endian in a couple of functions, just
put those values into local u32 and u16...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In *all* callers we have a dentry of child of that directory.
Just use ->d_parent of that one, for fsck sake...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) %d does _not_ produce a page worth of output
b) snprintf() doesn't return negatives - it used to in old glibc, but
that's the kernel...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use parent_inode has a flag for whether nfsd wants a connectable fh, but
generate one opportunistically so that we can take advantage of the
additional info in there.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pass inode + parent's inode or NULL instead of dentry + bool saying
whether we want the parent or not.
NOTE: that needs ceph fix folded in.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull x86 trampoline rework from H. Peter Anvin:
"This code reworks all the "trampoline"/"realmode" code (various bits
that need to live in the first megabyte of memory, most but not all of
which runs in real mode at some point) in the kernel into a single
object. The main reason for doing this is that it eliminates the last
place in the kernel where we needed pages to be mapped RWX. This code
separates all that code into proper R/RW/RX pages."
Fix up conflicts in arch/x86/kernel/Makefile (mca removed next to reboot
code), and arch/x86/kernel/reboot.c (reboot code moved around in one
branch, modified in this one), and arch/x86/tools/relocs.c (mostly same
code came in earlier due to working around the ld bugs just before the
3.4 release).
Also remove stale x86-relocs entry from scripts/.gitignore as per Peter
Anvin.
* commit '61f5446169': (36 commits)
x86, realmode: Move end signature into header.S
x86, relocs: When printing an error, say relative or absolute
x86, relocs: More relocations which may end up as absolute
x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
xen-acpi-processor: Add missing #include <xen/xen.h>
acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c
x86, realmode: Change EFER to a single u64 field
x86, realmode: Move kernel/realmode.c to realmode/init.c
x86, realmode: Move not-common bits out of trampoline_common.S
x86, realmode: Mask out EFER.LMA when saving trampoline EFER
x86, realmode: Fix no cache bits test in reboot_32.S
x86, realmode: Make sure all generated files are listed in targets
x86, realmode: build fix: remove duplicate build
x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
x86, realmode: fixes compilation issue in tboot.c
x86, realmode: move relocs from scripts/ to arch/x86/tools
x86, realmode: header for trampoline code
x86, realmode: flattened rm hierachy
x86, realmode: don't copy real_mode_header
x86, realmode: fix 64-bit wakeup sequence
...
