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  1. 22 9月, 2010 1 次提交
  3. 07 8月, 2010 1 次提交
    • D
      Fix init ordering of /dev/console vs callers of modprobe · 31d1d48e
      由 David Howells 提交于 
      Make /dev/console get initialised before any initialisation routine that
invokes modprobe because if modprobe fails, it's going to want to open
/dev/console, presumably to write an error message to.

The problem with that is that if the /dev/console driver is not yet
initialised, the chardev handler will call request_module() to invoke
modprobe, which will fail, because we never compile /dev/console as a
module.

This will lead to a modprobe loop, showing the following in the kernel
log:

	request_module: runaway loop modprobe char-major-5-1
	request_module: runaway loop modprobe char-major-5-1
	request_module: runaway loop modprobe char-major-5-1
	request_module: runaway loop modprobe char-major-5-1
	request_module: runaway loop modprobe char-major-5-1

This can happen, for example, when the built in md5 module can't find
the built in cryptomgr module (because the latter fails to initialise).
The md5 module comes before the call to tty_init(), presumably because
'crypto' comes before 'drivers' alphabetically.

Fix this by calling tty_init() from chrdev_init().
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      31d1d48e
  5. 07 4月, 2010 3 次提交
  7. 13 3月, 2010 2 次提交
  9. 03 2月, 2010 2 次提交
  11. 16 12月, 2009 6 次提交
  13. 10 12月, 2009 1 次提交
    • C
      vfs: Implement proper O_SYNC semantics · 6b2f3d1f
      由 Christoph Hellwig 提交于 
      While Linux provided an O_SYNC flag basically since day 1, it took until
Linux 2.4.0-test12pre2 to actually get it implemented for filesystems,
since that day we had generic_osync_around with only minor changes and the
great "For now, when the user asks for O_SYNC, we'll actually give
O_DSYNC" comment.  This patch intends to actually give us real O_SYNC
semantics in addition to the O_DSYNC semantics.  After Jan's O_SYNC
patches which are required before this patch it's actually surprisingly
simple, we just need to figure out when to set the datasync flag to
vfs_fsync_range and when not.

This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's
numerical value to keep binary compatibility, and adds a new real O_SYNC
flag.  To guarantee backwards compatiblity it is defined as expanding to
both the O_DSYNC and the new additional binary flag (__O_SYNC) to make
sure we are backwards-compatible when compiled against the new headers.

This also means that all places that don't care about the differences can
just check O_DSYNC and get the right behaviour for O_SYNC, too - only
places that actuall care need to check __O_SYNC in addition.  Drivers and
network filesystems have been updated in a fail safe way to always do the
full sync magic if O_DSYNC is set.  The few places setting O_SYNC for
lower layers are kept that way for now to stay failsafe.

We enforce that O_DSYNC is set when __O_SYNC is set early in the open path
to make sure we always get these sane options.

Note that parisc really screwed up their headers as they already define a
O_DSYNC that has always been a no-op.  We try to repair it by using it for
the new O_DSYNC and redefinining O_SYNC to send both the traditional
O_SYNC numerical value _and_ the O_DSYNC one.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger@sun.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Acked-by: NUlrich Drepper <drepper@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJan Kara <jack@suse.cz>
      6b2f3d1f
  15. 04 12月, 2009 1 次提交
  17. 14 10月, 2009 1 次提交
    • F
      mem_class: Drop the bkl from memory_open() · 205153aa
      由 Frederic Weisbecker 提交于 
      The generic open callback for the mem class devices is "protected" by
the bkl.

Let's look at the datas manipulated inside memory_open:

- inode and file: safe
- the devlist: safe because it is constant
- the memdev classes inside this array are safe too (constant)

After we find out which memdev file operation we need to use, we call
its open callback. Depending on the targeted memdev, we call either
open_port() that doesn't manipulate any racy data (just a capable()
check), or we call nothing.

So it's safe to remove the big kernel lock there.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1255113062-5835-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      205153aa
  19. 28 9月, 2009 1 次提交
  21. 24 9月, 2009 1 次提交
  23. 20 9月, 2009 1 次提交
  25. 16 9月, 2009 2 次提交
  27. 11 9月, 2009 1 次提交
  29. 19 6月, 2009 1 次提交
  31. 10 6月, 2009 1 次提交
    • L
      Make /dev/zero reads interruptible by signals · 2b838687
      由 Linus Torvalds 提交于 
      This helps with bad latencies for large reads from /dev/zero, but might
conceivably break some application that "knows" that a read of /dev/zero
cannot return early.  So do this early in the merge window to give us
maximal test coverage, even if the patch is totally trivial.

Obviously, no well-behaved application should ever depend on the read
being uninterruptible, but hey, bugs happen.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2b838687
  33. 05 6月, 2009 1 次提交
    • S
      drivers/char/mem.c: avoid OOM lockup during large reads from /dev/zero · 730c586a
      由 Salman Qazi 提交于 
      While running 20 parallel instances of dd as follows:

  #!/bin/bash
  for i in `seq 1 20`; do
           dd if=/dev/zero of=/export/hda3/dd_$i bs=1073741824 count=1 &
  done
  wait

on a 16G machine, we noticed that rather than just killing the processes,
the entire kernel went down.  Stracing dd reveals that it first does an
mmap2, which makes 1GB worth of zero page mappings.  Then it performs a
read on those pages from /dev/zero, and finally it performs a write.

The machine died during the reads.  Looking at the code, it was noticed
that /dev/zero's read operation had been changed by
557ed1fa ("remove ZERO_PAGE") from giving
zero page mappings to actually zeroing the page.

The zeroing of the pages causes physical pages to be allocated to the
process.  But, when the process exhausts all the memory that it can, the
kernel cannot kill it, as it is still in the kernel mode allocating more
memory.  Consequently, the kernel eventually crashes.

To fix this, I propose that when a fatal signal is pending during
/dev/zero read operation, we simply return and let the user process die.
Signed-off-by: NSalman Qazi <sqazi@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
[ Modified error return and comment trivially.  - Linus]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      730c586a
  35. 10 4月, 2009 1 次提交
  37. 07 1月, 2009 1 次提交
  39. 17 10月, 2008 1 次提交
  41. 25 7月, 2008 1 次提交
  43. 22 7月, 2008 1 次提交
  45. 20 7月, 2008 1 次提交
    • I
      Subject: devmem, x86: fix rename of CONFIG_NONPROMISC_DEVMEM · d092633b
      由 Ingo Molnar 提交于 
      From: Arjan van de Ven <arjan@infradead.org>
Date: Sat, 19 Jul 2008 15:47:17 -0700

CONFIG_NONPROMISC_DEVMEM was a rather confusing name - but renaming it
to CONFIG_PROMISC_DEVMEM causes problems on architectures that do not
support this feature; this patch renames it to CONFIG_STRICT_DEVMEM,
so that architectures can opt-in into it.

( the polarity of the option is still the same as it was originally; it
  needs to be for now to not break architectures that don't have the
  infastructure yet to support this feature)
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: "V.Radhakrishnan" <rk@atr-labs.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
---
      d092633b
  47. 18 7月, 2008 1 次提交
    • I
      x86: rename CONFIG_NONPROMISC_DEVMEM to CONFIG_PROMISC_DEVMEM · 64d206d8
      由 Ingo Molnar 提交于 
      Linus observed:

> The real bug is that we shouldn't have "double negatives", and
> certainly not negative config options. Making that "promiscuous
> /dev/mem" option a negated thing as a config option was bad.

right ... lets rename this option. There should never be a negation
in config options.

[ that reminds me of CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER, but that
  is for another commit ;-) ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      64d206d8
  49. 21 6月, 2008 1 次提交
  51. 29 4月, 2008 1 次提交
  53. 25 4月, 2008 4 次提交