linux.git/mm/filemap.c, branch v2.6.30

memcg: fix deadlock between lock_page_cgroup and mapping tree_lock

2009-05-29T15:40:02+00:00

mapping->tree_lock can be acquired from interrupt context.  Then,
following dead lock can occur.

Assume "A" as a page.

 CPU0:
       lock_page_cgroup(A)
		interrupted
			-> take mapping->tree_lock.
 CPU1:
       take mapping->tree_lock
		-> lock_page_cgroup(A)

This patch tries to fix above deadlock by moving memcg's hook to out of
mapping->tree_lock.  charge/uncharge of pagecache/swapcache is protected
by page lock, not tree_lock.

After this patch, lock_page_cgroup() is not called under mapping->tree_lock.

Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Daisuke Nishimura 
Cc: Balbir Singh 
Cc: Daisuke Nishimura 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Export filemap_write_and_wait_range

2009-04-16T14:47:49+00:00

This wasn't exported before and is useful (used by the experimental ext3
data=guarded code)

Signed-off-by: Chris Mason 
Acked-by: Theodore Tso 
Acked-by: Jan Kara 
Signed-off-by: Linus Torvalds

filemap: fix kernel-doc warnings

2009-04-13T22:04:30+00:00

Fix filemap.c kernel-doc warnings:

Warning(mm/filemap.c:575): No description found for parameter 'page'
Warning(mm/filemap.c:575): No description found for parameter 'waiter'

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Staging: pohmelfs: kconfig/makefile and vfs changes.

2009-04-03T21:53:36+00:00

This patch adds Kconfig and Makefile entries and exports to
VFS functions to be used by POHMELFS.

Signed-off-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

CacheFiles: Permit the page lock state to be monitored

2009-04-03T15:42:39+00:00

Add a function to install a monitor on the page lock waitqueue for a particular
page, thus allowing the page being unlocked to be detected.

This is used by CacheFiles to detect read completion on a page in the backing
filesystem so that it can then copy the data to the waiting netfs page.

Signed-off-by: David Howells 
Acked-by: Steve Dickson 
Acked-by: Trond Myklebust 
Acked-by: Rik van Riel 
Acked-by: Al Viro 
Tested-by: Daire Byrne

FS-Cache: Recruit a page flags for cache management

2009-04-03T15:42:36+00:00

Recruit a page flag to aid in cache management.  The following extra flag is
defined:

 (1) PG_fscache (PG_private_2)

     The marked page is backed by a local cache and is pinning resources in the
     cache driver.

If PG_fscache is set, then things that checked for PG_private will now also
check for that.  This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.

Signed-off-by: David Howells 
Acked-by: Steve Dickson 
Acked-by: Trond Myklebust 
Acked-by: Rik van Riel 
Acked-by: Al Viro 
Tested-by: Daire Byrne

x86, mm: dont use non-temporal stores in pagecache accesses

2009-03-02T10:06:49+00:00

Impact: standardize IO on cached ops

On modern CPUs it is almost always a bad idea to use non-temporal stores,
as the regression in this commit has shown it:

  30d697f: x86: fix performance regression in write() syscall

The kernel simply has no good information about whether using non-temporal
stores is a good idea or not - and trying to add heuristics only increases
complexity and inserts fragility.

The regression on cached write()s took very long to be found - over two
years. So dont take any chances and let the hardware decide how it makes
use of its caches.

The only exception is drivers/gpu/drm/i915/i915_gem.c: there were we are
absolutely sure that another entity (the GPU) will pick up the dirty
data immediately and that the CPU will not touch that data before the
GPU will.

Also, keep the _nocache() primitives to make it easier for people to
experiment with these details. There may be more clear-cut cases where
non-cached copies can be used, outside of filemap.c.

Cc: Salman Qazi 
Cc: Nick Piggin 
Cc: Linus Torvalds 
Signed-off-by: Ingo Molnar

x86, mm: pass in 'total' to __copy_from_user_*nocache()

2009-02-25T09:20:03+00:00

Impact: cleanup, enable future change

Add a 'total bytes copied' parameter to __copy_from_user_*nocache(),
and update all the callsites.

The parameter is not used yet - architecture code can use it to
more intelligently decide whether the copy should be cached or
non-temporal.

Cc: Salman Qazi 
Cc: Nick Piggin 
Cc: Linus Torvalds 
Signed-off-by: Ingo Molnar

[CVE-2009-0029] System call wrapper special cases

2009-01-14T13:15:18+00:00

System calls with an unsigned long long argument can't be converted with
the standard wrappers since that would include a cast to long, which in
turn means that we would lose the upper 32 bit on 32 bit architectures.
Also semctl can't use the standard wrapper since it has a 'union'
parameter.

So we handle them as special case and add some extra wrappers instead.

Signed-off-by: Heiko Carstens

[CVE-2009-0029] Convert all system calls to return a long

2009-01-14T13:15:14+00:00

Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens