The idea behind a RAID class is to provide a uniform interface to all
RAID subsystems (both hardware and software) in the kernel.
To do that, I've made this class a transport class that's entirely
subsystem independent (although the matching routines have to match per
subsystem, as you'll see looking at the code). I put it in the scsi
subdirectory purely because I needed somewhere to play with it, but it's
not a scsi specific module.
I used a fusion raid card as the test bed for this; with that kind of
card, this is the type of class output you get:
jejb@titanic> ls -l /sys/class/raid_devices/20\:0\:0\:0/
total 0
lrwxrwxrwx 1 root root 0 Aug 16 17:21 component-0 -> ../../../devices/pci0000:80/0000:80:04.0/host20/target20:1:0/20:1:0:0/
lrwxrwxrwx 1 root root 0 Aug 16 17:21 component-1 -> ../../../devices/pci0000:80/0000:80:04.0/host20/target20:1:1/20:1:1:0/
lrwxrwxrwx 1 root root 0 Aug 16 17:21 device -> ../../../devices/pci0000:80/0000:80:04.0/host20/target20:0:0/20:0:0:0/
-r--r--r-- 1 root root 16384 Aug 16 17:21 level
-r--r--r-- 1 root root 16384 Aug 16 17:21 resync
-r--r--r-- 1 root root 16384 Aug 16 17:21 state
So it's really simple: for a SCSI device representing a hardware raid,
it shows the raid level, the array state, the resync % complete (if the
state is resyncing) and the underlying components of the RAID (these are
exposed in fusion on the virtual channel 1).
As you can see, this type of information can be exported by almost
anything, including software raid.
The more difficult trick, of course, is going to be getting it to
perform configuration type actions with writable attributes.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
One of the changes in the attribute_container code in the scsi-misc tree
was to add a lock to protect the list of devices per container. This,
unfortunately, leads to potential scheduling while atomic problems if
there's a sleep in the function called by a trigger.
The correct solution is to use the kernel klist infrastructure instead
which allows lockless traversal of a list.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
attribute_container_classdev_to_container is an exported function of the
attribute_container.c file. However, there's no prototype for it. Now
I actually want to use it, so add one.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
I recently tried to construct a totally generic transport class and
found there were certain features missing from the current abstract
transport class. Most notable is that you have to hang the data on the
class_device but most of the API is framed in terms of the generic
device, not the class_device.
These changes are two fold
- Provide the class_device to all of the setup and configure APIs
- Provide and extra API to take the device and the attribute class and
return the corresponding class_device
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch is necessary if we begin exposing underlying physical disks
(which can attach to the SPI transport class) of the hardware RAID
cards, since we don't want any SPI parameters binding to the RAID
devices.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
There are certain rogue devices (and the aic7xxx driver) that return
BUSY or QUEUE_FULL forever. This code will apply a global timeout (of
the total number of retries times the per command timer) to a given
command. If it is exceeded, the command is completed regardless of its
state.
The patch also removes the unused field in the command: timeout and
timeout_total.
This solves the problem of detecting an endless loop in the mid-layer
because of BUSY/QUEUE_FULL bouncing, but will not recover the device.
In the aic7xxx case, the driver can be recovered by sending a bus reset,
so possibly this should be tied into the error handler?
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This parameter is important only to people who take the time to tune the
margin control settings, otherwise it's completely irrelevant. However,
just in case anyone should want to do this, it's appropriate to include
the parameter.
I don't do anything with it in DV by design, so the parameter will come
up as off by default, so if anyone actually wants to play with the
margin control settings they'll have to enable it under the
spi_transport class first.
I also updated the transfer settings display to report all of the PPR
settings instead of only DT, IU and QAS
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Add support to not allow additions to a host when it is being removed.
Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Migrate the current SCSI host state model to a model like SCSI
device is using.
Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
sync_tsc was using smp_call_function to ask the boot processor to report
it's tsc value. smp_call_function performs an IPI_send_allbutself which is
a broadcast ipi. There is a window during processor startup during which
the target cpu has started and before it has initialized it's interrupt
vectors so it can properly process an interrupt. Receveing an interrupt
during that window will triple fault the cpu and do other nasty things.
Why cli does not protect us from that is beyond me.
The simple fix is to match ia64 and provide a smp_call_function_single.
Which avoids the broadcast and is more efficient.
This certainly fixes the problem of getting stuck on boot which was
very easy to trigger on my SMP Hyperthreaded Xeon, and I think
it fixes it for the right reasons.
Minor changes by AK
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the patch from:
http://www.uwsg.iu.edu/hypermail/linux/kernel/0506.3/0985.html
Is the the following line suppose inside the if CONFIG_PCI=n
#define pci_dma_burst_advice(pdev, strat, strategy_parameter) do { } while (0)
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the standard hardware page table manipulation macros.
This is possible now that linux works with all 4 levels
of the page tables.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some edge problems with the original C rewrite.
Thanks go to Cal Peake, who pinpointed the breakage to the rewrite, and
tested this fixed version.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We added an include of asm/vm86.h in include/asm-i386/ptrace.h. Since UML
includes the underlying arch's ptrace.h, it needs an asm/vm86.h in order to
build.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch eliminates the GCC4 warning on the x86_64 platform:
kernel/sched.c:1824: warning: control may reach end of non-void function
'sched_find_first_bit' being inlined.
The change follows the lead of others, i.e. it is guaranteed that at least
one of b[0], b[1], or b[2] will have a bit set and evaluate to true. That
being said, GCC4.0.0 notices that the code flow does not return anything if
b[0], b[1] and b[2] are not true. Since we know better, if it's not b[0] or
b[1], it has to be b[2].
Signed-off-by: Jesse Millan <jessem@cs.pdx.edu>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This avoids some potential stack overflows with very deep softirq callchains.
i386 does this too.
TOADD CFI annotation
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This avoids confusing the disassembler. Costs 2 bytes per BUG.
Thanks to Suresh Siddha and Jan Beulich for suggesting suitable instructions.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Harmless because the kernel didn't use it. Noticed by Travis Betak
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Were either outdated or misleading.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Minor cleanup.
Move things into their include files, remove obsolete includes, fix
indentation, remove obsolete special cases etc.
I also added the per cpu section to asm-generic/sections.h and fixed
init/main.c to use it.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Makes it slightly more efficient.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We sometimes forgot to check whether the exclusive store succeeded.
Ensure that we always check. Also ensure that we always use the
out of line versions, since the inline versions are not SMP safe.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It may shut up gcc, but it also incorrectly changes the semantics of the
smp_call_function() helpers.
You can fix the warning other ways if you are interested (create another
inline function that takes no arguments and returns zero), but
preferably gcc just shouldn't complain about unused return values from
statement expressions in the first place.
Avoid using "rep scas", just let the compiler select a sequence of
regular instructions.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Apparently gcc 4.0 complains about "({ 0; });", which leads to -Werror
breakage in one of the alpha oprofile modules.
One might could argue that this is a gcc bug, in that statement-expressions
should be considered to be function-like rather than statement-like for the
purposes of this warning. But it's just as easy to use an inline function
in the first place, side-stepping the issue.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
EMU10K1/EMU10K2 driver
It allows the user to force the snd-emu10k1 module to think the user
has a particular sound card. Useful if their particular sound card
is not yet recognised.
Signed-off-by: James Courtier-Dutton <James@superbug.co.uk>
ALSA Core
This patch changes, adds and remove some comments, which will
make now more sense and fit on a 80-char line. It also changes
the order of snd_power_wait() to make the file more readable.
It removes the device.c comment in front of _snd_minor,
cause snd_minor has nothing to do with device.c.
The both typos in the kernel-docs were corrected too.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
`gcc -W' likes to complain if the static keyword is not at the beginning of
the declaration. This patch fixes all remaining occurrences of "inline
static" up with "static inline" in the entire kernel tree (140 occurrences in
47 files).
While making this change I came across a few lines with trailing whitespace
that I also fixed up, I have also added or removed a blank line or two here
and there, but there are no functional changes in the patch.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following possible cleanups:
- make two needlessly global structs static
- #if 0 the EXPORT_SYMBOL'ed but unused function tveeprom_dump
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use tabs for formatting like anywhere else in this file.
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
turn many #if $undefined_string into #ifdef $undefined_string to fix some
warnings after -Wno-def was added to global CFLAGS
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The cache parameter to mb_cache_shrink isn't used. We may as well remove
it.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I believe that there is a problem with the handling of POSIX locks, which
the attached patch should address.
The problem appears to be a race between fcntl(2) and close(2). A
multithreaded application could close a file descriptor at the same time as
it is trying to acquire a lock using the same file descriptor. I would
suggest that that multithreaded application is not providing the proper
synchronization for itself, but the OS should still behave correctly.
SUS3 (Single UNIX Specification Version 3, read: POSIX) indicates that when
a file descriptor is closed, that all POSIX locks on the file, owned by the
process which closed the file descriptor, should be released.
The trick here is when those locks are released. The current code releases
all locks which exist when close is processing, but any locks in progress
are handled when the last reference to the open file is released.
There are three cases to consider.
One is the simple case, a multithreaded (mt) process has a file open and
races to close it and acquire a lock on it. In this case, the close will
release one reference to the open file and when the fcntl is done, it will
release the other reference. For this situation, no locks should exist on
the file when both the close and fcntl operations are done. The current
system will handle this case because the last reference to the open file is
being released.
The second case is when the mt process has dup(2)'d the file descriptor.
The close will release one reference to the file and the fcntl, when done,
will release another, but there will still be at least one more reference
to the open file. One could argue that the existence of a lock on the file
after the close has completed is okay, because it was acquired after the
close operation and there is still a way for the application to release the
lock on the file, using an existing file descriptor.
The third case is when the mt process has forked, after opening the file
and either before or after becoming an mt process. In this case, each
process would hold a reference to the open file. For each process, this
degenerates to first case above. However, the lock continues to exist
until both processes have released their references to the open file. This
lock could block other lock requests.
The changes to release the lock when the last reference to the open file
aren't quite right because they would allow the lock to exist as long as
there was a reference to the open file. This is too long.
The new proposed solution is to add support in the fcntl code path to
detect a race with close and then to release the lock which was just
acquired when such as race is detected. This causes locks to be released
in a timely fashion and for the system to conform to the POSIX semantic
specification.
This was tested by instrumenting a kernel to detect the handling locks and
then running a program which generates case #3 above. A dangling lock
could be reliably generated. When the changes to detect the close/fcntl
race were added, a dangling lock could no longer be generated.
Cc: Matthew Wilcox <willy@debian.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The atomic64 primitives are supposed to have 64-bit parameters instead of int.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The find_next_{zero}_bit primitives on s390* should never return a bit number
bigger then the bit field size. In the case of a bitfield that doesn't end on
a word boundary, an offset that makes the search start at the last word of the
bit field and the last word doesn't contain any zero/one bits the search is
continued with a call to find_first_bit with a negative size. The search
normally ends pretty quickly because the words following the bit field contain
a mix of zeros and ones. But the bit number that is returned in this case is
too big.
To fix this and additional if to check for this case is needed. To make the
code easier to read I removed the assembler parts from the
find_next_{zero}_bit functions, the C-ified code is as good.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Split spin lock and r/w lock implementation into a single try which is done
inline and an out of line function that repeatedly tries to get the lock
before doing the cpu_relax(). Add a system control to set the number of
retries before a cpu is yielded.
The reason for the spin lock retry is that the diagnose 0x44 that is used to
give up the virtual cpu is quite expensive. For spin locks that are held only
for a short period of time the costs of the diagnoses outweights the savings
for spin locks that are held for a longer timer. The default retry count is
1000.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These changes are untested (I no longer have the hardware).
Signed-off-by: Miles Bader <miles@gnu.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
