23 Oct, 2010
1 commit
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* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
15 Oct, 2010
1 commit
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All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====Signed-off-by: Arnd Bergmann
Cc: Julia Lawall
Cc: Christoph Hellwig
05 Oct, 2010
1 commit
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All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.These drivers do not seem to be under active
maintainance from my brief investigation. Apologies
to those maintainers that I have missed.file=$1
name=$2
if grep -q lock_kernel ${file} ; then
if grep -q 'include.*linux.mutex.h' ${file} ; then
sed -i '/include.*/d' ${file}
else
sed -i 's/include.*.*$/include /g' ${file}
fi
sed -i ${file} \
-e "/^#include.*linux.mutex.h/,$ {
1,/^\(static\|int\|long\)/ {
/^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);} }" \
-e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
-e '/[ ]*cycle_kernel_lock();/d'
else
sed -i -e '/include.*\/d' ${file} \
-e '/cycle_kernel_lock()/d'
fiSigned-off-by: Arnd Bergmann
17 Oct, 2008
1 commit
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Now that device_create() has been audited, rename things back to the
original call to be sane.Signed-off-by: Greg Kroah-Hartman
22 Jul, 2008
1 commit
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device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.Signed-off-by: Greg Kroah-Hartman
21 Jun, 2008
1 commit
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Signed-off-by: Jonathan Corbet
30 Apr, 2008
1 commit
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__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Oct, 2007
1 commit
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Convert from class_device to device in drivers/char.
Signed-off-by: Tony Jones
Signed-off-by: Kay Sievers
Signed-off-by: Greg Kroah-Hartman
05 Oct, 2006
1 commit
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Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.Signed-Off-By: David Howells
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
03 Aug, 2006
1 commit
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Add a platform check to the snsc driver init function, to prevent
loading on non-sn2 systems.Signed-off-by: Greg Edwards
Signed-off-by: Tony Luck
04 Jul, 2006
1 commit
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Mark the static struct file_operations in drivers/char as const. Making
them const prevents accidental bugs, and moves them to the .rodata section
so that they no longer do any false sharing; in addition with the proper
debug option they are then protected against corruption..[akpm@osdl.org: build fix]
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Jul, 2006
1 commit
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Signed-off-by: Thomas Gleixner
Cc: Ingo Molnar
Cc: "David S. Miller"
Cc: Benjamin Herrenschmidt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Apr, 2006
1 commit
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from: Greg Howard
Fix Altix system controller (snsc) device names to include the slot number
of the blade whose associated system controller is the target of the device
interface. Including the slot number avoids a problem we're currently
having where slots within the same enclosure are attempting to create
multiple kobjects with identical names.Signed-off-by: Greg Howard
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Mar, 2006
1 commit
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Change driver to use kzalloc rather than kmalloc+memset
Signed-off-by: Jes Sorensen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2005
2 commits
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The previous patch adding the ability to nest struct class_device
changed the paramaters to the call class_device_create(). This patch
fixes up all in-kernel users of the function.Signed-off-by: Greg Kroah-Hartman
16 Sep, 2005
1 commit
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Some of the SN code & #defines related to compact nodes & IO discovery
have gotten stale over the years. This patch attempts to clean them up.
Some of the various SN MAX_xxx #defines were also unclear & misused.The primary changes are:
- use MAX_NUMNODES. This is the generic linux #define for the number
of nodes that are known to the generic kernel. Arrays & loops
for constructs that are 1:1 with linux-defined nodes should
use the linux #define - not an SN equivalent.- use MAX_COMPACT_NODES for MAX_NUMNODES + NUM_TIOS. This is the
number of nodes in the SSI system. Compact nodes are a hack to
get around the IA64 architectural limit of 256 nodes. Large SGI
systems have more than 256 nodes. When we upgrade to ACPI3.0,
I _hope_ that all nodes will be real nodes that are known to
the generic kernel. That will allow us to delete the notion
of "compact nodes".- add MAX_NUMALINK_NODES for the total number of nodes that
are in the numalink domain - all partitions.- simplified (understandable) scan_for_ionodes()
- small amount of cleanup related to cnodes
Signed-off-by: Jack Steiner
Signed-off-by: Tony Luck
21 Jun, 2005
2 commits
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Fix a typo in scdrv_init() which was breaking the build for SGI sn2.
Signed-off-by: Jason Uhlenkott
Signed-off-by: Andrew Morton
Signed-off-by: Greg Kroah-Hartman -
Signed-off-by: Greg Kroah-Hartman
26 Apr, 2005
1 commit
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The following is an update of the patch I sent yesterday
(3/9/05) incorporating suggestions from Christoph Hellwig and
Andreas Schwab. It allows Altix and Altix-like systems to
handle environmental events generated by the system controllers,
and should apply on top of Jack Steiner's patch of 3/1/05 ("New
chipset support for SN platform") and Mark Goodwin's patch of
3/8/05 ("Altix SN topology support for new chipsets and pci
topology").Signed-off-by: Greg Howard
Signed-off-by: Tony Luck
17 Apr, 2005
1 commit
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Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.Let it rip!
