Commit Graph

302 Commits

Author SHA1 Message Date
Heiko Carstens bdc480e3be [CVE-2009-0029] System call wrappers part 10
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:22 +01:00
Takashi Sato fcccf50254 filesystem freeze: implement generic freeze feature
The ioctls for the generic freeze feature are below.
o Freeze the filesystem
  int ioctl(int fd, int FIFREEZE, arg)
    fd: The file descriptor of the mountpoint
    FIFREEZE: request code for the freeze
    arg: Ignored
    Return value: 0 if the operation succeeds. Otherwise, -1

o Unfreeze the filesystem
  int ioctl(int fd, int FITHAW, arg)
    fd: The file descriptor of the mountpoint
    FITHAW: request code for unfreeze
    arg: Ignored
    Return value: 0 if the operation succeeds. Otherwise, -1
    Error number: If the filesystem has already been unfrozen,
                  errno is set to EINVAL.

[akpm@linux-foundation.org: fix CONFIG_BLOCK=n]
Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com>
Cc: <xfs-masters@oss.sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09 16:54:42 -08:00
Takashi Sato c4be0c1dc4 filesystem freeze: add error handling of write_super_lockfs/unlockfs
Currently, ext3 in mainline Linux doesn't have the freeze feature which
suspends write requests.  So, we cannot take a backup which keeps the
filesystem's consistency with the storage device's features (snapshot and
replication) while it is mounted.

In many case, a commercial filesystem (e.g.  VxFS) has the freeze feature
and it would be used to get the consistent backup.

If Linux's standard filesystem ext3 has the freeze feature, we can do it
without a commercial filesystem.

So I have implemented the ioctls of the freeze feature.
I think we can take the consistent backup with the following steps.
1. Freeze the filesystem with the freeze ioctl.
2. Separate the replication volume or create the snapshot
   with the storage device's feature.
3. Unfreeze the filesystem with the unfreeze ioctl.
4. Take the backup from the separated replication volume
   or the snapshot.

This patch:

VFS:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they can return an error.
Rename write_super_lockfs and unlockfs of the super block operation
freeze_fs and unfreeze_fs to avoid a confusion.

ext3, ext4, xfs, gfs2, jfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that write_super_lockfs returns an error if needed,
and unlockfs always returns 0.

reiserfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they always return 0 (success) to keep a current behavior.

Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com>
Cc: <xfs-masters@oss.sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09 16:54:42 -08:00
Franck Bui-Huu 69e9930993 block_write_begin(): remove useless goto
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:08 -08:00
Nick Piggin 54566b2c15 fs: symlink write_begin allocation context fix
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened.  They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim.  This bug could
cause filesystem deadlocks.

The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called.  It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock.  The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.

Add a new flag for write_begin, AOP_FLAG_NOFS.  Filesystems can now act on
this flag in their write_begin function.  Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).

This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg.  ocfs2_alloc_write_ctxt, for a
random example).

[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
  untouched to the grab_cache_page_write_begin() function.  That
  just simplifies everybody, and may even allow future expansion of the
  logic.   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-04 13:33:20 -08:00
Keith Mannthey 08bafc0341 block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set
Allow the scsi request REQ_QUIET flag to be propagated to the buffer
file system layer. The basic ideas is to pass the flag from the scsi
request to the bio (block IO) and then to the buffer layer.  The buffer
layer can then suppress needless printks.

This patch declutters the kernel log by removed the 40-50 (per lun)
buffer io error messages seen during a boot in my multipath setup . It
is a good chance any real errors will be missed in the "noise" it the
logs without this patch.

During boot I see blocks of messages like
"
__ratelimit: 211 callbacks suppressed
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242847
Buffer I/O error on device sdm, logical block 1
Buffer I/O error on device sdm, logical block 5242878
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242872
"
in my logs.

My disk environment is multipath fiber channel using the SCSI_DH_RDAC
code and multipathd.  This topology includes an "active" and "ghost"
path for each lun. IO's to the "ghost" path will never complete and the
SCSI layer, via the scsi device handler rdac code, quick returns the IOs
to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi
layer messages.

 I am wanting to extend the QUIET behavior to include the buffer file
system layer to deal with these errors as well. I have been running this
patch for a while now on several boxes without issue.  A few runs of
bonnie++ show no noticeable difference in performance in my setup.

Thanks for John Stultz for the quiet_error finalization.

Submitted-by:  Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29 08:28:44 +01:00
Jan Kara 52b19ac993 udf: Fix BUG_ON() in destroy_inode()
udf_clear_inode() can leave behind buffers on mapping's i_private list (when
we truncated preallocation). Call invalidate_inode_buffers() so that the list
is properly cleaned-up before we return from udf_clear_inode(). This is ugly
and suggest that we should cleanup preallocation earlier than in clear_inode()
but currently there's no such call available since drop_inode() is called under
inode lock and thus is unusable for disk operations.

Signed-off-by: Jan Kara <jack@suse.cz>
2008-11-27 17:38:28 +01:00
Nick Piggin 51b07fc3c5 fs: buffer lock use lock bitops
trylock_buffer and unlock_buffer open and close a critical section.
Hence, we can use the lock bitops to get the desired memory ordering.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:32 -07:00
Jens Axboe 48fd4f93a0 block: submit_bh() inadvertently discards barrier flag on a sync write
Reported by Milan Broz <mbroz@redhat.com>, commit 18ce3751 inadvertently
made submit_bh() discard the barrier bit for a WRITE_SYNC request. Fix
that up.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-08-27 09:50:19 +02:00
Nick Piggin ca5de404ff fs: rename buffer trylock
Like the page lock change, this also requires name change, so convert the
raw test_and_set bitop to a trylock.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-04 21:56:09 -07:00
Thomas Petazzoni dbacefc9c4 fs/buffer.c: uninline __remove_assoc_queue()
Uninline the __remove_assoc_queue() function in fs/buffer.c, called at too
many places and too long to really be inlined.  Size results:

   text	   data	    bss	    dec	    hex	filename
1134606	 118840	 212992	1466438	 166046	vmlinux.old
1134303	 118840	 212992	1466135	 165f17	vmlinux
   -303       0       0    -303    -12F +/-

This patch is part of the Linux Tiny project and has been originally
written by Matt Mackall <mpm@selenic.com>.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 09:41:46 -07:00
Hisashi Hifumi 8ab22b9abb vfs: pagecache usage optimization for pagesize!=blocksize
When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.

I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment.  Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.

So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate.  This can
reduce read IO and improve system throughput.

I wrote a benchmark program and got result number with this program.

This benchmark do:

  1: mount and open a test file.

  2: create a 512MB file.

  3: close a file and umount.

  4: mount and again open a test file.

  5: pwrite randomly 300000 times on a test file.  offset is aligned
     by IO size(1024bytes).

  6: measure time of preading randomly 100000 times on a test file.

The result was:
	2.6.26
        330 sec

	2.6.26-patched
        226 sec

Arch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GB

On ext3/4, a file is written through buffer/block.  So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment.  This test result
showed this.

The benchmark program is as follows:

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>

#define LEN 1024
#define LOOP 1024*512 /* 512MB */

main(void)
{
	unsigned long i, offset, filesize;
	int fd;
	char buf[LEN];
	time_t t1, t2;

	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
		perror("cannot mount\n");
		exit(1);
	}
	memset(buf, 0, LEN);
	fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
	if (fd < 0) {
		perror("cannot open file\n");
		exit(1);
	}
	for (i = 0; i < LOOP; i++)
		write(fd, buf, LEN);
	close(fd);
	if (umount("/root/test1/") < 0) {
		perror("cannot umount\n");
		exit(1);
	}
	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
		perror("cannot mount\n");
		exit(1);
	}
	fd = open("/root/test1/testfile", O_RDWR);
	if (fd < 0) {
		perror("cannot open file\n");
		exit(1);
	}

	filesize = LEN * LOOP;
	for (i = 0; i < 300000; i++){
		offset = (random() % filesize) & (~(LEN - 1));
		pwrite(fd, buf, LEN, offset);
	}
	printf("start test\n");
	time(&t1);
	for (i = 0; i < 100000; i++){
		offset = (random() % filesize) & (~(LEN - 1));
		pread(fd, buf, LEN, offset);
	}
	time(&t2);
	printf("%ld sec\n", t2-t1);
	close(fd);
	if (umount("/root/test1/") < 0) {
		perror("cannot umount\n");
		exit(1);
	}
}

Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28 16:30:21 -07:00
Arjan van de Ven 5c752ad9f3 Use WARN() in fs/
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00
Alexey Dobriyan 51cc50685a SL*B: drop kmem cache argument from constructor
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres.  Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.

Non-trivial places are:
	arch/powerpc/mm/init_64.c
	arch/powerpc/mm/hugetlbpage.c

This is flag day, yes.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00
Nick Piggin 19fd623127 mm: spinlock tree_lock
mapping->tree_lock has no read lockers.  convert the lock from an rwlock
to a spinlock.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:06 -07:00
Ingo Molnar 1a781a777b Merge branch 'generic-ipi' into generic-ipi-for-linus
Conflicts:

	arch/powerpc/Kconfig
	arch/s390/kernel/time.c
	arch/x86/kernel/apic_32.c
	arch/x86/kernel/cpu/perfctr-watchdog.c
	arch/x86/kernel/i8259_64.c
	arch/x86/kernel/ldt.c
	arch/x86/kernel/nmi_64.c
	arch/x86/kernel/smpboot.c
	arch/x86/xen/smp.c
	include/asm-x86/hw_irq_32.h
	include/asm-x86/hw_irq_64.h
	include/asm-x86/mach-default/irq_vectors.h
	include/asm-x86/mach-voyager/irq_vectors.h
	include/asm-x86/smp.h
	kernel/Makefile

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 21:55:59 +02:00
Alex Tomas 29a814d2ee vfs: add hooks for ext4's delayed allocation support
Export mpage_bio_submit() and __mpage_writepage() for the benefit of
ext4's delayed allocation support.   Also change __block_write_full_page
so that if buffers that have the BH_Delay flag set it will call
get_block() to get the physical block allocated, just as in the
!BH_Mapped case.

Signed-off-by: Alex Tomas <alex@clusterfs.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Jan Kara c7d206b337 vfs: Move mark_inode_dirty() from under page lock in generic_write_end()
There's no need to call mark_inode_dirty() under page lock in
generic_write_end(). It unnecessarily makes hold time of page lock longer
and more importantly it forces locking order of page lock and transaction
start for journaling filesystems.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Jens Axboe 18ce3751cc Properly notify block layer of sync writes
fsync_buffers_list() and sync_dirty_buffer() both issue async writes and
then immediately wait on them. Conceptually, that makes them sync writes
and we should treat them as such so that the IO schedulers can handle
them appropriately.

This patch fixes a write starvation issue that Lin Ming reported, where
xx is stuck for more than 2 minutes because of a large number of
synchronous IO in the system:

INFO: task kjournald:20558 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
kjournald     D ffff810010820978  6712 20558      2
ffff81022ddb1d10 0000000000000046 ffff81022e7baa10 ffffffff803ba6f2
ffff81022ecd0000 ffff8101e6dc9160 ffff81022ecd0348 000000008048b6cb
0000000000000086 ffff81022c4e8d30 0000000000000000 ffffffff80247537
Call Trace:
[<ffffffff803ba6f2>] kobject_get+0x12/0x17
[<ffffffff80247537>] getnstimeofday+0x2f/0x83
[<ffffffff8029c1ac>] sync_buffer+0x0/0x3f
[<ffffffff8066d195>] io_schedule+0x5d/0x9f
[<ffffffff8029c1e7>] sync_buffer+0x3b/0x3f
[<ffffffff8066d3f0>] __wait_on_bit+0x40/0x6f
[<ffffffff8029c1ac>] sync_buffer+0x0/0x3f
[<ffffffff8066d48b>] out_of_line_wait_on_bit+0x6c/0x78
[<ffffffff80243909>] wake_bit_function+0x0/0x23
[<ffffffff8029e3ad>] sync_dirty_buffer+0x98/0xcb
[<ffffffff8030056b>] journal_commit_transaction+0x97d/0xcb6
[<ffffffff8023a676>] lock_timer_base+0x26/0x4b
[<ffffffff8030300a>] kjournald+0xc1/0x1fb
[<ffffffff802438db>] autoremove_wake_function+0x0/0x2e
[<ffffffff80302f49>] kjournald+0x0/0x1fb
[<ffffffff802437bb>] kthread+0x47/0x74
[<ffffffff8022de51>] schedule_tail+0x28/0x5d
[<ffffffff8020cac8>] child_rip+0xa/0x12
[<ffffffff80243774>] kthread+0x0/0x74
[<ffffffff8020cabe>] child_rip+0x0/0x12

Lin Ming confirms that this patch fixes the issue. I've run tests with
it for the past week and no ill effects have been observed, so I'm
proposing it for inclusion into 2.6.26.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-01 09:07:34 +02:00
Jens Axboe 15c8b6c1aa on_each_cpu(): kill unused 'retry' parameter
It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26 11:24:38 +02:00
Harvey Harrison 8e24eea728 fs: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:54 -07:00
Adrian Bunk f1e3af72c1 make fs/buffer.c:cont_expand_zero() static
cont_expand_zero() can become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:01 -07:00
Adrian Bunk 946a57b526 remove generic_commit_write()
Remove the obsolete and no longer used generic_commit_write().

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:01 -07:00
OGAWA Hirofumi 061e97469f Add balance_dirty_pages_ratelimited() to cont_expand_zero()
On the systems, ftruncate() which expand size for FAT became the cause
of OOM.  The cont_expand_zero() filled all memory with dirty pages,
and since disk is very slow, limit of page scanning was exceeded, then
it triggered OOM.

This adds balance_dirty_pages_ratelimited() to avoid filling memory
with dirty pages.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:47 -07:00
Mel Gorman 19770b3260 mm: filter based on a nodemask as well as a gfp_mask
The MPOL_BIND policy creates a zonelist that is used for allocations
controlled by that mempolicy.  As the per-node zonelist is already being
filtered based on a zone id, this patch adds a version of __alloc_pages() that
takes a nodemask for further filtering.  This eliminates the need for
MPOL_BIND to create a custom zonelist.

A positive benefit of this is that allocations using MPOL_BIND now use the
local node's distance-ordered zonelist instead of a custom node-id-ordered
zonelist.  I.e., pages will be allocated from the closest allowed node with
available memory.

[Lee.Schermerhorn@hp.com: Mempolicy: update stale documentation and comments]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask rework]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:19 -07:00
Mel Gorman dd1a239f6f mm: have zonelist contains structs with both a zone pointer and zone_idx
Filtering zonelists requires very frequent use of zone_idx().  This is costly
as it involves a lookup of another structure and a substraction operation.  As
the zone_idx is often required, it should be quickly accessible.  The node idx
could also be stored here if it was found that accessing zone->node is
significant which may be the case on workloads where nodemasks are heavily
used.

This patch introduces a struct zoneref to store a zone pointer and a zone
index.  The zonelist then consists of an array of these struct zonerefs which
are looked up as necessary.  Helpers are given for accessing the zone index as
well as the node index.

[kamezawa.hiroyu@jp.fujitsu.com: Suggested struct zoneref instead of embedding information in pointers]
[hugh@veritas.com: mm-have-zonelist: fix memcg ooms]
[hugh@veritas.com: just return do_try_to_free_pages]
[hugh@veritas.com: do_try_to_free_pages gfp_mask redundant]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:18 -07:00
Mel Gorman 54a6eb5c47 mm: use two zonelist that are filtered by GFP mask
Currently a node has two sets of zonelists, one for each zone type in the
system and a second set for GFP_THISNODE allocations.  Based on the zones
allowed by a gfp mask, one of these zonelists is selected.  All of these
zonelists consume memory and occupy cache lines.

This patch replaces the multiple zonelists per-node with two zonelists.  The
first contains all populated zones in the system, ordered by distance, for
fallback allocations when the target/preferred node has no free pages.  The
second contains all populated zones in the node suitable for GFP_THISNODE
allocations.

An iterator macro is introduced called for_each_zone_zonelist() that interates
through each zone allowed by the GFP flags in the selected zonelist.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:18 -07:00
Mel Gorman 0e88460da6 mm: introduce node_zonelist() for accessing the zonelist for a GFP mask
Introduce a node_zonelist() helper function.  It is used to lookup the
appropriate zonelist given a node and a GFP mask.  The patch on its own is a
cleanup but it helps clarify parts of the two-zonelist-per-node patchset.  If
necessary, it can be merged with the next patch in this set without problems.

Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:18 -07:00
Mel Gorman dac1d27bc8 mm: use zonelists instead of zones when direct reclaiming pages
The following patches replace multiple zonelists per node with two zonelists
that are filtered based on the GFP flags.  The patches as a set fix a bug with
regard to the use of MPOL_BIND and ZONE_MOVABLE.  With this patchset, the
MPOL_BIND will apply to the two highest zones when the highest zone is
ZONE_MOVABLE.  This should be considered as an alternative fix for the
MPOL_BIND+ZONE_MOVABLE in 2.6.23 to the previously discussed hack that filters
only custom zonelists.

The first patch cleans up an inconsistency where direct reclaim uses
zonelist->zones where other places use zonelist.

The second patch introduces a helper function node_zonelist() for looking up
the appropriate zonelist for a GFP mask which simplifies patches later in the
set.

The third patch defines/remembers the "preferred zone" for numa statistics, as
it is no longer always the first zone in a zonelist.

The forth patch replaces multiple zonelists with two zonelists that are
filtered.  The two zonelists are due to the fact that the memoryless patchset
introduces a second set of zonelists for __GFP_THISNODE.

The fifth patch introduces helper macros for retrieving the zone and node
indices of entries in a zonelist.

The final patch introduces filtering of the zonelists based on a nodemask.
Two zonelists exist per node, one for normal allocations and one for
__GFP_THISNODE.

Performance results varied depending on the machine configuration.  In real
workloads the gain/loss will depend on how much the userspace portion of the
benchmark benefits from having more cache available due to reduced referencing
of zonelists.

These are the range of performance losses/gains when running against
2.6.24-rc4-mm1.  The set and these machines are a mix of i386, x86_64 and
ppc64 both NUMA and non-NUMA.
			     loss   to  gain
Total CPU time on Kernbench: -0.86% to  1.13%
Elapsed   time on Kernbench: -0.79% to  0.76%
page_test from aim9:         -4.37% to  0.79%
brk_test  from aim9:         -0.71% to  4.07%
fork_test from aim9:         -1.84% to  4.60%
exec_test from aim9:         -0.71% to  1.08%

This patch:

The allocator deals with zonelists which indicate the order in which zones
should be targeted for an allocation.  Similarly, direct reclaim of pages
iterates over an array of zones.  For consistency, this patch converts direct
reclaim to use a zonelist.  No functionality is changed by this patch.  This
simplifies zonelist iterators in the next patch.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:18 -07:00
Christoph Lameter 488514d179 Remove set_migrateflags()
Migrate flags must be set on slab creation as agreed upon when the antifrag
logic was reviewed.  Otherwise some slabs of a slabcache will end up in the
unmovable and others in the reclaimable section depending on which flag was
active when a new slab page was allocated.

This likely slid in somehow when antifrag was merged. Remove it.

The buffer_heads are always allocated with __GFP_RECLAIMABLE because the
SLAB_RECLAIM_ACCOUNT option is set.  The set_migrateflags() never had any
effect there.

Radix tree allocations are not directly reclaimable but they are allocated
with __GFP_RECLAIMABLE set on each allocation.  We now set
SLAB_RECLAIM_ACCOUNT on radix tree slab creation making sure that radix
tree slabs are consistently placed in the reclaimable section.  Radix tree
slabs will also be accounted as such.

There is then no user left of set_migratepages. So remove it.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:17 -07:00
Linus Torvalds 1be62dc190 Be more careful about marking buffers dirty
Mikulas Patocka noted that the optimization where we check if a buffer
was already dirty (and we avoid re-dirtying it) was not really SMP-safe.

Since the read of the old status was not synchronized with anything, an
aggressive CPU re-ordering of memory accesses might have moved that read
up to before the data was even written to the buffer, and another CPU
that cleaned it again, causing the newly dirty state to never actually
hit the disk.

Admittedly this would probably never trigger in practice, but it's still
wrong.

Mikulas sent a patch that fixed the problem, but I dislike the subtlety
of the whole optimization, so this is an alternate fix that is more
explicit about the particular SMP ordering for the optimization, and
separates out the speculative reads of the buffer state into its own
conditional (and makes the memory barrier only happen if we are likely
to actually hit the optimized case in the first place).

I considered removing the optimization entirely, but Andrew argued for
it's continued existence. I'm a push-over.

Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-04 14:38:17 -07:00
Dmitri Monakhov 5b41e74ad1 vfs: fix data leak in nobh_write_end()
Current nobh_write_end() implementation ignore partial writes(copied < len)
case if page was fully mapped and simply mark page as Uptodate, which is
totally wrong because area [pos+copied, pos+len) wasn't updated explicitly in
previous write_begin call.  It simply contains garbage from pagecache and
result in data leakage.

#TEST_CASE_BEGIN:
~~~~~~~~~~~~~~~~
In fact issue triggered by classical testcase
	open("/mnt/test", O_RDWR|O_CREAT|O_TRUNC, 0666) = 3
	ftruncate(3, 409600)                    = 0
	writev(3, [{"a", 1}, {NULL, 4095}], 2)  = 1
##TESTCASE_SOURCE:
~~~~~~~~~~~~~~~~~
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/uio.h>
#include <sys/mman.h>
#include <errno.h>
int main(int argc, char **argv)
{
	int fd,  ret;
	void* p;
	struct iovec iov[2];
	fd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666);
	ftruncate(fd, 409600);
	iov[0].iov_base="a";
	iov[0].iov_len=1;
	iov[1].iov_base=NULL;
	iov[1].iov_len=4096;
	ret = writev(fd, iov, sizeof(iov)/sizeof(struct iovec));
	printf("writev  = %d, err = %d\n", ret, errno);
	return 0;
}
##TESTCASE RESULT:
~~~~~~~~~~~~~~~~~~
[root@ts63 ~]# mount | grep mnt2
/dev/mapper/test on /mnt2 type ext2 (rw,nobh)
[root@ts63 ~]#  /tmp/writev /mnt2/test
writev  = 1, err = 0
[root@ts63 ~]# hexdump -C /mnt2/test

00000000  61 65 62 6f 6f 74 00 00  f0 b9 b4 59 3a 00 00 00  |aeboot.....Y:...|
00000010  20 00 00 00 00 00 00 00  21 00 00 00 00 00 00 00  | .......!.......|
00000020  df df df df df df df df  df df df df df df df df  |................|
00000030  3a 00 00 00 2a 00 00 00  21 00 00 00 00 00 00 00  |:...*...!.......|
00000040  60 c0 8c 00 00 00 00 00  40 4a 8d 00 00 00 00 00  |`.......@J......|
00000050  00 00 00 00 00 00 00 00  41 00 00 00 00 00 00 00  |........A.......|
00000060  74 69 6d 65 20 64 64 20  69 66 3d 2f 64 65 76 2f  |time dd if=/dev/|
00000070  6c 6f 6f 70 30 20 20 6f  66 3d 2f 64 65 76 2f 6e  |loop0  of=/dev/n|
skip..
00000f50  00 00 00 00 00 00 00 00  31 00 00 00 00 00 00 00  |........1.......|
00000f60  6d 6b 66 73 2e 65 78 74  33 20 2f 64 65 76 2f 76  |mkfs.ext3 /dev/v|
00000f70  7a 76 67 2f 74 65 73 74  20 2d 62 34 30 39 36 00  |zvg/test -b4096.|
00000f80  a0 fe 8c 00 00 00 00 00  21 00 00 00 00 00 00 00  |........!.......|
00000f90  23 31 32 30 35 39 35 30  34 30 34 00 3a 00 00 00  |#1205950404.:...|
00000fa0  20 00 8d 00 00 00 00 00  21 00 00 00 00 00 00 00  | .......!.......|
00000fb0  d0 cf 8c 00 00 00 00 00  10 d0 8c 00 00 00 00 00  |................|
00000fc0  00 00 00 00 00 00 00 00  41 00 00 00 00 00 00 00  |........A.......|
00000fd0  6d 6f 75 6e 74 20 2f 64  65 76 2f 76 7a 76 67 2f  |mount /dev/vzvg/|
00000fe0  74 65 73 74 20 20 2f 76  7a 20 2d 6f 20 64 61 74  |test  /vz -o dat|
00000ff0  61 3d 77 72 69 74 65 62  61 63 6b 00 00 00 00 00  |a=writeback.....|
00001000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|

As you can see file's page contains garbage from pagecache instead of zeros.
#TEST_CASE_END

Attached patch:
- Add sanity check BUG_ON in order to prevent incorrect usage by caller,
  This is function invariant because page can has buffers and in no zero
  *fadata pointer at the same time.
- Always attach buffers to page is it is partial write case.
- Always switch back to generic_write_end if page has buffers.
  This is reasonable because if page already has buffer then generic_write_begin
  was called previously.

Signed-off-by: Dmitri Monakhov <dmonakhov@openvz.org>
Reviewed-by: Nick Piggin <npiggin@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-28 14:45:21 -07:00
Randy Dunlap a6b91919e0 fs: fix kernel-doc notation warnings
Fix kernel-doc notation warnings in fs/.

Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line:
 *	mark_files_ro
Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
 *	lease_get_mtime
Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
 *	lease_get_mtime
Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line:
 * lookup_one_len:  filesystem helper to lookup single pathname component
Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line:
 * bh_uptodate_or_lock: Test whether the buffer is uptodate
Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line:
 * bh_submit_read: Submit a locked buffer for reading
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line:
 * writeback_acquire: attempt to get exclusive writeback access to a device
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line:
 * writeback_in_progress: determine whether there is writeback in progress
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line:
 * writeback_release: relinquish exclusive writeback access against a device.
Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections
Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections
Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line:
 * void journal_invalidatepage()

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Jan Kara e3892296de vfs: fix NULL pointer dereference in fsync_buffers_list()
Fix NULL pointer dereference in fsync_buffers_list() introduced by recent fix
of races in private_list handling.  Since bh->b_assoc_map has been cleared in
__remove_assoc_queue() we should really use original value stored in the
'mapping' variable.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:10 -08:00
Randy Dunlap 78a4a50a86 docbook: fix filesystems.tmpl source files
Fix docbook problems in filesystems.tmpl.
These cause the generated docbook to be incorrect.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-03 10:47:13 -08:00
Jan Kara 535ee2fbf7 buffer_head: fix private_list handling
There are two possible races in handling of private_list in buffer cache.

1) When fsync_buffers_list() processes a private_list, it clears
   b_assoc_mapping and moves buffer to its private list.  Now
   drop_buffers() comes, sees a buffer is on list so it calls
   __remove_assoc_queue() which complains about b_assoc_mapping being
   cleared (as it cannot propagate possible IO error).  This race has been
   actually observed in the wild.

2) When fsync_buffers_list() processes a private_list,
   mark_buffer_dirty_inode() can be called on bh which is already on the
   private list of fsync_buffers_list().  As buffer is on some list (note
   that the check is performed without private_lock), it is not readded to
   the mapping's private_list and after fsync_buffers_list() finishes, we
   have a dirty buffer which should be on private_list but it isn't.  This
   race has not been reported, probably because most (but not all) callers
   of mark_buffer_dirty_inode() hold i_mutex and thus are serialized with
   fsync().

Fix these issues by not clearing b_assoc_map when fsync_buffers_list()
moves buffer to a dedicated list and by reinserting buffer in private_list
when it is found dirty after we have submitted buffer for IO.  We also
change the tests whether a buffer is on a private list from
!list_empty(&bh->b_assoc_buffers) to bh->b_assoc_map so that they are
single word reads and hence lockless checks are safe.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:42 -08:00
Harvey Harrison fc9b52cd8f fs: remove fastcall, it is always empty
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:31 -08:00
Nick Piggin 9db5579be4 rewrite rd
This is a rewrite of the ramdisk block device driver.

The old one is really difficult because it effectively implements a block
device which serves data out of its own buffer cache.  It relies on the dirty
bit being set, to pin its backing store in cache, however there are non
trivial paths which can clear the dirty bit (eg.  try_to_free_buffers()),
which had recently lead to data corruption.  And in general it is completely
wrong for a block device driver to do this.

The new one is more like a regular block device driver.  It has no idea about
vm/vfs stuff.  It's backing store is similar to the buffer cache (a simple
radix-tree of pages), but it doesn't know anything about page cache (the pages
in the radix tree are not pagecache pages).

There is one slight downside -- direct block device access and filesystem
metadata access goes through an extra copy and gets stored in RAM twice.
However, this downside is only slight, because the real buffercache of the
device is now reclaimable (because we're not playing crazy games with it), so
under memory intensive situations, footprint should effectively be the same --
maybe even a slight advantage to the new driver because it can also reclaim
buffer heads.

The fact that it now goes through all the regular vm/fs paths makes it
much more useful for testing, too.

   text    data     bss     dec     hex filename
   2837     849     384    4070     fe6 drivers/block/rd.o
   3528     371      12    3911     f47 drivers/block/brd.o

Text is larger, but data and bss are smaller, making total size smaller.

A few other nice things about it:
- Similar structure and layout to the new loop device handlinag.
- Dynamic ramdisk creation.
- Runtime flexible buffer head size (because it is no longer part of the
  ramdisk code).
- Boot / load time flexible ramdisk size, which could easily be extended
  to a per-ramdisk runtime changeable size (eg. with an ioctl).
- Can use highmem for the backing store.

[akpm@linux-foundation.org: fix build]
[byron.bbradley@gmail.com: make rd_size non-static]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Byron Bradley <byron.bbradley@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:30 -08:00
Christoph Lameter b98938c373 bufferhead: revert constructor removal
The constructor for buffer_head slabs was removed recently.  We need the
constructor back in slab defrag in order to insure that slab objects always
have a definite state even before we allocated them.

I think we mistakenly merged the removal of the constuctor into a cleanup
patch.  You (ie: akpm) had a test that showed that the removal of the
constructor led to a small regression.  The prior state makes things easier
for slab defrag.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:14 -08:00
Christoph Lameter eebd2aa355 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user
Simplify page cache zeroing of segments of pages through 3 functions

zero_user_segments(page, start1, end1, start2, end2)

        Zeros two segments of the page. It takes the position where to
        start and end the zeroing which avoids length calculations and
	makes code clearer.

zero_user_segment(page, start, end)

        Same for a single segment.

zero_user(page, start, length)

        Length variant for the case where we know the length.

We remove the zero_user_page macro. Issues:

1. Its a macro. Inline functions are preferable.

2. The KM_USER0 macro is only defined for HIGHMEM.

   Having to treat this special case everywhere makes the
   code needlessly complex. The parameter for zeroing is always
   KM_USER0 except in one single case that we open code.

Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.

Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.

Also extract the flushing of the caches to be outside of the kmap.

[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:13 -08:00
Aneesh Kumar K.V 389d1b083c Add buffer head related helper functions
Add buffer head related helper function bh_uptodate_or_lock and
bh_submit_read which can be used by file system

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2008-01-28 23:58:26 -05:00
Nick Piggin efdc31319d nobh: nobh_write_end fix
This path mustn't have been tested :( I did attempt to exercise it
by injecting failures here, but I suspect PageMappedToDisk may have
been getting in the way. Will need more of a look, although I think
nobh mode is OK for an -rc1 (it shouldn't eat anyone's data).

Commit 03158cd7eb ("fs: restore nobh")
introcduced a NULL deref.  Spotted by the Coverity checker.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-21 08:54:05 -07:00
Fengguang Wu 1f7decf6d9 writeback: remove pages_skipped accounting in __block_write_full_page()
Miklos Szeredi <miklos@szeredi.hu> and me identified a writeback bug:

> The following strange behavior can be observed:
>
> 1. large file is written
> 2. after 30 seconds, nr_dirty goes down by 1024
> 3. then for some time (< 30 sec) nothing happens (disk idle)
> 4. then nr_dirty again goes down by 1024
> 5. repeat from 3. until whole file is written
>
> So basically a 4Mbyte chunk of the file is written every 30 seconds.
> I'm quite sure this is not the intended behavior.

It can be produced by the following test scheme:

# cat bin/test-writeback.sh
grep nr_dirty /proc/vmstat
echo 1 > /proc/sys/fs/inode_debug
dd if=/dev/zero of=/var/x bs=1K count=204800&
while true; do grep nr_dirty /proc/vmstat; sleep 1; done

# bin/test-writeback.sh
nr_dirty 19207
nr_dirty 19207
nr_dirty 30924
204800+0 records in
204800+0 records out
209715200 bytes (210 MB) copied, 1.58363 seconds, 132 MB/s
nr_dirty 47150
nr_dirty 47141
nr_dirty 47142
nr_dirty 47142
nr_dirty 47142
nr_dirty 47142
nr_dirty 47205
nr_dirty 47214
nr_dirty 47214
nr_dirty 47214
nr_dirty 47214
nr_dirty 47214
nr_dirty 47215
nr_dirty 47216
nr_dirty 47216
nr_dirty 47216
nr_dirty 47154
nr_dirty 47143
nr_dirty 47143
nr_dirty 47143
nr_dirty 47143
nr_dirty 47143
nr_dirty 47142
nr_dirty 47142
nr_dirty 47142
nr_dirty 47142
nr_dirty 47134
nr_dirty 47134
nr_dirty 47135
nr_dirty 47135
nr_dirty 47135
nr_dirty 46097 <== -1038
nr_dirty 46098
nr_dirty 46098
nr_dirty 46098
[...]
nr_dirty 46091
nr_dirty 46092
nr_dirty 46092
nr_dirty 45069 <== -1023
nr_dirty 45056
nr_dirty 45056
nr_dirty 45056
[...]
nr_dirty 37822
nr_dirty 36799 <== -1023
[...]
nr_dirty 36781
nr_dirty 35758 <== -1023
[...]
nr_dirty 34708
nr_dirty 33672 <== -1024
[...]
nr_dirty 33692
nr_dirty 32669 <== -1023

% ls -li /var/x
847824 -rw-r--r-- 1 root root 200M 2007-08-12 04:12 /var/x

% dmesg|grep 847824  # generated by a debug printk
[  529.263184] redirtied inode 847824 line 548
[  564.250872] redirtied inode 847824 line 548
[  594.272797] redirtied inode 847824 line 548
[  629.231330] redirtied inode 847824 line 548
[  659.224674] redirtied inode 847824 line 548
[  689.219890] redirtied inode 847824 line 548
[  724.226655] redirtied inode 847824 line 548
[  759.198568] redirtied inode 847824 line 548

# line 548 in fs/fs-writeback.c:
543                 if (wbc->pages_skipped != pages_skipped) {
544                         /*
545                          * writeback is not making progress due to locked
546                          * buffers.  Skip this inode for now.
547                          */
548                         redirty_tail(inode);
549                 }

More debug efforts show that __block_write_full_page()
never has the chance to call submit_bh() for that big dirty file:
the buffer head is *clean*. So basicly no page io is issued by
__block_write_full_page(), hence pages_skipped goes up.

Also the comment in generic_sync_sb_inodes():

544                         /*
545                          * writeback is not making progress due to locked
546                          * buffers.  Skip this inode for now.
547                          */

and the comment in __block_write_full_page():

1713                 /*
1714                  * The page was marked dirty, but the buffers were
1715                  * clean.  Someone wrote them back by hand with
1716                  * ll_rw_block/submit_bh.  A rare case.
1717                  */

do not quite agree with each other. The page writeback should be skipped for
'locked buffer', but here it is 'clean buffer'!

This patch fixes this bug. Though I'm not sure why __block_write_full_page()
is called only to do nothing and who actually issued the writeback for us.

This is the two possible new behaviors after the patch:

1) pretty nice: wait 30s and write ALL:)
2) not so good:
	- during the dd: ~16M
	- after 30s:      ~4M
	- after 5s:       ~4M
	- after 5s:     ~176M

The next patch will fix case (2).

Cc: David Chinner <dgc@sgi.com>
Cc: Ken Chen <kenchen@google.com>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:02 -07:00
Peter Zijlstra c9e51e4180 mm: count reclaimable pages per BDI
Count per BDI reclaimable pages; nr_reclaimable = nr_dirty + nr_unstable.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:45 -07:00
Mel Gorman e12ba74d8f Group short-lived and reclaimable kernel allocations
This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations.  When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.

This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE.  The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved.  i.e.  they can be migrated by deleting
them and re-reading the information from elsewhere.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:00 -07:00
Nick Piggin 03158cd7eb fs: restore nobh
Implement nobh in new aops.  This is a bit tricky.  FWIW, nobh_truncate is
now implemented in a way that does not create blocks in sparse regions,
which is a silly thing for it to have been doing (isn't it?)

ext2 survives fsx and fsstress. jfs is converted as well... ext3
should be easy to do (but not done yet).

[akpm@linux-foundation.org: coding-style fixes]
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00
Nick Piggin a20fa20c54 With reiserfs no longer using the weird generic_cont_expand, remove it completely.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin 89e107877b fs: new cont helpers
Rework the generic block "cont" routines to handle the new aops.  Supporting
cont_prepare_write would take quite a lot of code to support, so remove it
instead (and we later convert all filesystems to use it).

write_begin gets passed AOP_FLAG_CONT_EXPAND when called from
generic_cont_expand, so filesystems can avoid the old hacks they used.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin afddba49d1 fs: introduce write_begin, write_end, and perform_write aops
These are intended to replace prepare_write and commit_write with more
flexible alternatives that are also able to avoid the buffered write
deadlock problems efficiently (which prepare_write is unable to do).

[mark.fasheh@oracle.com: API design contributions, code review and fixes]
[akpm@linux-foundation.org: various fixes]
[dmonakhov@sw.ru: new aop block_write_begin fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin 637aff46f9 fs: fix data-loss on error
New buffers against uptodate pages are simply be marked uptodate, while the
buffer_new bit remains set.  This causes error-case code to zero out parts of
those buffers because it thinks they contain stale data: wrong, they are
actually uptodate so this is a data loss situation.

Fix this by actually clearning buffer_new and marking the buffer dirty.  It
makes sense to always clear buffer_new before setting a buffer uptodate.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin a4b0672db3 fs: fix nobh error handling
nobh mode error handling is not just pretty slack, it's wrong.

One cannot zero out the whole page to ensure new blocks are zeroed, because
it just brings the whole page "uptodate" with zeroes even if that may not
be the correct uptodate data.  Also, other parts of the page may already
contain dirty data which would get lost by zeroing it out.  Thirdly, the
writeback of zeroes to the new blocks will also erase existing blocks.  All
these conditions are pagecache and/or filesystem corruption.

The problem comes about because we didn't keep track of which buffers
actually are new or old.  However it is not enough just to keep only this
state, because at the point we start dirtying parts of the page (new
blocks, with zeroes), the handling of IO errors becomes impossible without
buffers because the page may only be partially uptodate, in which case the
page flags allone cannot capture the state of the parts of the page.

So allocate all buffers for the page upfront, but leave them unattached so
that they don't pick up any other references and can be freed when we're
done.  If the error path is hit, then zero the new buffers as the regular
buffer path does, then attach the buffers to the page so that it can
actually be written out correctly and be subject to the normal IO error
handling paths.

As an upshot, we save 1K of kernel stack on ia64 or powerpc 64K page
systems.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:54 -07:00
Dmitry Monakhov 68671f35fe mm: add end_buffer_read helper function
Move duplicated code from end_buffer_read_XXX methods to separate helper
function.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:53 -07:00
NeilBrown 6712ecf8f6 Drop 'size' argument from bio_endio and bi_end_io
As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant.  Remove it.

Now there is no need for bio_endio to subtract the size completed
from bi_size.  So don't do that either.

While we are at it, change bi_end_io to return void.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10 09:25:57 +02:00
Nick Piggin 1833633803 fix some conversion overflows
Fix page index to offset conversion overflows in buffer layer, ecryptfs,
and ocfs2.

It would be nice to convert the whole tree to page_offset, but for now
just fix the bugs.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20 08:44:19 -07:00
David Chinner 5417169026 [FS] Implement block_page_mkwrite.
Many filesystems need a ->page-mkwrite callout to correctly
set up pages that have been written to by mmap. This is especially
important when mmap is writing into holes as it allows filesystems
to correctly account for and allocate space before the mmap
write is allowed to proceed.

Protection against truncate races is provided by locking the page
and checking to see whether the page mapping is correct and whether
it is beyond EOF so we don't end up allowing allocations beyond
the current EOF or changing EOF as a result of a mmap write.

SGI-PV: 940392
SGI-Modid: 2.6.x-xfs-melb:linux:29146a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-19 19:50:50 +10:00
Nick Piggin 787d2214c1 fs: introduce some page/buffer invariants
It is a bug to set a page dirty if it is not uptodate unless it has
buffers.  If the page has buffers, then the page may be dirty (some buffers
dirty) but not uptodate (some buffers not uptodate).  The exception to this
rule is if the set_page_dirty caller is racing with truncate or invalidate.

A buffer can not be set dirty if it is not uptodate.

If either of these situations occurs, it indicates there could be some data
loss problem.  Some of these warnings could be a harmless one where the
page or buffer is set uptodate immediately after it is dirtied, however we
should fix those up, and enforce this ordering.

Bring the order of operations for truncate into line with those of
invalidate.  This will prevent a page from being able to go !uptodate while
we're holding the tree_lock, which is probably a good thing anyway.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Andy Whitcroft 5ad333eb66 Lumpy Reclaim V4
When we are out of memory of a suitable size we enter reclaim.  The current
reclaim algorithm targets pages in LRU order, which is great for fairness at
order-0 but highly unsuitable if you desire pages at higher orders.  To get
pages of higher order we must shoot down a very high proportion of memory;
>95% in a lot of cases.

This patch set adds a lumpy reclaim algorithm to the allocator.  It targets
groups of pages at the specified order anchored at the end of the active and
inactive lists.  This encourages groups of pages at the requested orders to
move from active to inactive, and active to free lists.  This behaviour is
only triggered out of direct reclaim when higher order pages have been
requested.

This patch set is particularly effective when utilised with an
anti-fragmentation scheme which groups pages of similar reclaimability
together.

This patch set is based on Peter Zijlstra's lumpy reclaim V2 patch which forms
the foundation.  Credit to Mel Gorman for sanitity checking.

Mel said:

  The patches have an application with hugepage pool resizing.

  When lumpy-reclaim is used used with ZONE_MOVABLE, the hugepages pool can
  be resized with greater reliability.  Testing on a desktop machine with 2GB
  of RAM showed that growing the hugepage pool with ZONE_MOVABLE on it's own
  was very slow as the success rate was quite low.  Without lumpy-reclaim,
  each attempt to grow the pool by 100 pages would yield 1 or 2 hugepages.
  With lumpy-reclaim, getting 40 to 70 hugepages on each attempt was typical.

[akpm@osdl.org: ia64 pfn_to_nid fixes and loop cleanup]
[bunk@stusta.de: static declarations for internal functions]
[a.p.zijlstra@chello.nl: initial lumpy V2 implementation]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Mel Gorman 769848c038 Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated
It is often known at allocation time whether a page may be migrated or not.
This patch adds a flag called __GFP_MOVABLE and a new mask called
GFP_HIGH_MOVABLE.  Allocations using the __GFP_MOVABLE can be either migrated
using the page migration mechanism or reclaimed by syncing with backing
storage and discarding.

An API function very similar to alloc_zeroed_user_highpage() is added for
__GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable().  The
flags used by alloc_zeroed_user_highpage() are not changed because it would
change the semantics of an existing API.  After this patch is applied there
are no in-kernel users of alloc_zeroed_user_highpage() so it probably should
be marked deprecated if this patch is merged.

Note that this patch includes a minor cleanup to the use of __GFP_ZERO in
shmem.c to keep all flag modifications to inode->mapping in the
shmem_dir_alloc() helper function.  This clean-up suggestion is courtesy of
Hugh Dickens.

Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the
concept.  Credit to Hugh Dickens for catching issues with shmem swap vector
and ramfs allocations.

[akpm@linux-foundation.org: build fix]
[hugh@veritas.com: __GFP_ZERO cleanup]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Eric W. Biederman 4a2d44590a buffer: kill old incorrect comment
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:45 -07:00
OGAWA Hirofumi ff1be9ad61 Fix "fs: convert core functions to zero_user_page"
The bug was introduced by 01f2705daf.
It misses to convert the first argument, it should be "new_page".

This became a cause of fatfs corruption.

Cc: Nate Diller <nate.diller@gmail.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21 09:15:32 -07:00
Christoph Lameter ea125892a1 Fix page allocation flags in grow_dev_page()
grow_dev_page() simply passes GFP_NOFS to find_or_create_page.  This means
the allocation of radix tree nodes is done with GFP_NOFS and the allocation
of a new page is done using GFP_NOFS.

The mapping has a flags field that contains the necessary allocation flags
for the page cache allocation.  These need to be consulted in order to get
DMA and HIGHMEM allocations etc right.  And yes a blockdev could be
allowing Highmem allocations if its a ramdisk.

Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:06 -07:00
Christoph Lameter a35afb830f Remove SLAB_CTOR_CONSTRUCTOR
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Rafael J. Wysocki 8bb7844286 Add suspend-related notifications for CPU hotplug
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Nate Diller 01f2705daf fs: convert core functions to zero_user_page
It's very common for file systems to need to zero part or all of a page,
the simplist way is just to use kmap_atomic() and memset().  There's
actually a library function in include/linux/highmem.h that does exactly
that, but it's confusingly named memclear_highpage_flush(), which is
descriptive of *how* it does the work rather than what the *purpose* is.
So this patchset renames the function to zero_user_page(), and calls it
from the various places that currently open code it.

This first patch introduces the new function call, and converts all the
core kernel callsites, both the open-coded ones and the old
memclear_highpage_flush() ones.  Following this patch is a series of
conversions for each file system individually, per AKPM, and finally a
patch deprecating the old call.  The diffstat below shows the entire
patchset.

[akpm@linux-foundation.org: fix a few things]
Signed-off-by: Nate Diller <nate.diller@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:55 -07:00
Randy Dunlap e63340ae6b header cleaning: don't include smp_lock.h when not used
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:07 -07:00
Andrew Morton 7e4c3690b0 block_write_full_page(): report ENOSPC
block_write_full_page() forgot to propagate ENPSOC into the address_space.

Cc: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
Christoph Lameter 50953fe9e0 slab allocators: Remove SLAB_DEBUG_INITIAL flag
I have never seen a use of SLAB_DEBUG_INITIAL.  It is only supported by
SLAB.

I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again?  The callback is
performed before each freeing of an object.

I would think that it is much easier to check the object state manually
before the free.  That also places the check near the code object
manipulation of the object.

Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on.  If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code.  But there is no such code
in the kernel.  I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e.  add debug code before kfree).

There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches.  Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.

This is the last slab flag that SLUB did not support.  Remove the check for
unimplemented flags from SLUB.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
Peter Zijlstra f9a14399ae mm: optimize kill_bdev()
Remove duplicate work in kill_bdev().

It currently invalidates and then truncates the bdev's mapping.
invalidate_mapping_pages() will opportunistically remove pages from the
mapping.  And truncate_inode_pages() will forcefully remove all pages.

The only thing truncate doesn't do is flush the bh lrus.  So do that
explicitly.  This avoids (very unlikely) but possible invalid lookup
results if the same bdev is quickly re-issued.

It also will prevent extreme kernel latencies which are observed when
blockdevs which have a large amount of pagecache are unmounted, by avoiding
invalidate_mapping_pages() on that path.  invalidate_mapping_pages() has no
cond_resched (it can be called under spinlock), whereas truncate_inode_pages()
has one.

[akpm@linux-foundation.org: restore nrpages==0 optimisation]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
Peter Zijlstra f98393a64c mm: remove destroy_dirty_buffers from invalidate_bdev()
Remove the destroy_dirty_buffers argument from invalidate_bdev(), it hasn't
been used in 6 years (so akpm says).

find * -name \*.[ch] | xargs grep -l invalidate_bdev |
while read file; do
	quilt add $file;
	sed -ie 's/invalidate_bdev(\([^,]*\),[^)]*)/invalidate_bdev(\1)/g' $file;
done

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
Nick Piggin 3d67f2d7c0 fs: buffer don't PageUptodate without page locked
__block_write_full_page is calling SetPageUptodate without the page locked.
This is unusual, but not incorrect, as PG_writeback is still set.

However the next patch will require that SetPageUptodate always be called with
the page locked.  Simply don't bother setting the page uptodate in this case
(it is unusual that the write path does such a thing anyway).  Instead just
leave it to the read side to bring the page uptodate when it notices that all
buffers are uptodate.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:51 -07:00
Dave Kleikamp 57bf63d69c [PATCH] fs: nobh_truncate_page() fix
This fixes a regression caused by 22c8ca78f2.

nobh_prepare_write() no longer marks the page uptodate, so
nobh_truncate_page() needs to do it.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06 09:30:25 -08:00
Nick Piggin 22c8ca78f2 [PATCH] fs: fix nobh data leak
nobh_prepare_write leaks data similarly to how simple_prepare_write did. Fix
by not marking the page uptodate until nobh_commit_write time. Again, this
could break weird use-cases, but none appear to exist in the tree.

We can safely remove the set_page_dirty, because as the comment says,
nobh_commit_write does set_page_dirty. If a filesystem wants to allocate
backing store for a page dirtied via mmap, page_mkwrite is the suggested
approach.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20 17:10:15 -08:00
Nick Piggin ffda9d3022 [PATCH] fs: fix __block_write_full_page error case buffer submission
Andrew noticed that unlocking the page before submitting all buffers for
writeout could cause problems if the IO completes before we've finished
messing around with the page buffers, and they subsequently get freed.

Even if there were no bug, it is a good idea to bring the error case
into line with the common case here.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20 17:10:13 -08:00
Tomasz Kvarsin 3991d3bd15 [PATCH] warning fix: unsigned->signed
While compiling my code with -Wconversion using gcc-trunk, I always get a
bunch of warrning from headers, here is fix for them:

__getblk is alawys called with unsigned argument,
but it takes signed, the same story with __bread,__breadahead and so on.

Signed-off-by: Tomasz Kvarsin
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:29 -08:00
David Chinner 33a266dda9 [PATCH] Make BH_Unwritten a first class bufferhead flag V2
Currently, XFS uses BH_PrivateStart for flagging unwritten extent state in a
bufferhead.  Recently, I found the long standing mmap/unwritten extent
conversion bug, and it was to do with partial page invalidation not clearing
the unwritten flag from bufferheads attached to the page but beyond EOF.  See
here for a full explaination:

http://oss.sgi.com/archives/xfs/2006-12/msg00196.html

The solution I have checked into the XFS dev tree involves duplicating code
from block_invalidatepage to clear the unwritten flag from the bufferhead(s),
and then calling block_invalidatepage() to do the rest.

Christoph suggested that this would be better solved by pushing the unwritten
flag into the common buffer head flags and just adding the call to
discard_buffer():

http://oss.sgi.com/archives/xfs/2006-12/msg00239.html

The following patch makes BH_Unwritten a first class citizen.

Signed-off-by: Dave Chinner <dgc@sgi.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:27 -08:00
Nick Piggin 72ed3d0358 [PATCH] buffer: memorder fix
unlock_buffer(), like unlock_page(), must not clear the lock without
ensuring that the critical section is closed.

Mingming later sent the same patch, saying:

  We are running SDET benchmark and saw double free issue for ext3 extended
  attributes block, which complains the same xattr block already being freed (in
  ext3_xattr_release_block()).  The problem could also been triggered by
  multiple threads loop untar/rm a kernel tree.

  The race is caused by missing a memory barrier at unlock_buffer() before the
  lock bit being cleared, resulting in possible concurrent h_refcounter update.
  That causes a reference counter leak, then later leads to the double free that
  we have seen.

  Inside unlock_buffer(), there is a memory barrier is placed *after* the lock
  bit is being cleared, however, there is no memory barrier *before* the bit is
  cleared.  On some arch the h_refcount update instruction and the clear bit
  instruction could be reordered, thus leave the critical section re-entered.

  The race is like this: For example, if the h_refcount is initialized as 1,

  cpu 0:                                   cpu1
  --------------------------------------   -----------------------------------
  lock_buffer() /* test_and_set_bit */
  clear_buffer_locked(bh);
                                          lock_buffer() /* test_and_set_bit */
  h_refcount = h_refcount+1; /* = 2*/     h_refcount = h_refcount + 1; /*= 2 */
                                          clear_buffer_locked(bh);
  ....                                    ......

  We lost a h_refcount here. We need a memory barrier before the buffer head lock
  bit being cleared to force the order of the two writes.  Please apply.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 11:15:24 -08:00
Andrew Morton fc0ecff698 [PATCH] remove invalidate_inode_pages()
Convert all calls to invalidate_inode_pages() into open-coded calls to
invalidate_mapping_pages().

Leave the invalidate_inode_pages() wrapper in place for now, marked as
deprecated.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:31 -08:00
Nick Piggin 87df7241bd [PATCH] Fix try_to_free_buffer() locking
Fix commit ecdfc9787f

Not to put too fine a point on it, but in a nutshell...

	__set_page_dirty_buffers() | try_to_free_buffers()
	---------------------------+---------------------------
	                           | spin_lock(private_lock);
	                           | drop_bufers()
	                           | spin_unlock(private_lock);
	spin_lock(private_lock)    |
	!page_has_buffers()        |
	spin_unlock(private_lock)  |
	SetPageDirty()             |
	                           | cancel_dirty_page()

                          oops!

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-29 20:20:42 -08:00
Linus Torvalds ecdfc9787f Resurrect 'try_to_free_buffers()' VM hackery
It's not pretty, but it appears that ext3 with data=journal will clean
pages without ever actually telling the VM that they are clean.  This,
in turn, will result in the VM (and balance_dirty_pages() in particular)
to never realize that the pages got cleaned, and wait forever for an
event that already happened.

Technically, this seems to be a problem with ext3 itself, but it used to
be hidden by 'try_to_free_buffers()' noticing this situation on its own,
and just working around the filesystem problem.

This commit re-instates that hack, in order to avoid a regression for
the 2.6.20 release. This fixes bugzilla 7844:

	http://bugzilla.kernel.org/show_bug.cgi?id=7844

Peter Zijlstra points out that we should probably retain the debugging
code that this removes from cancel_dirty_page(), and I agree, but for
the imminent release we might as well just silence the warning too
(since it's not a new bug: anything that triggers that warning has been
around forever).

Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26 12:47:06 -08:00
David Chinner f73ca1b76c [PATCH] Revert bd_mount_mutex back to a semaphore
Revert bd_mount_mutex back to a semaphore so that xfs_freeze -f /mnt/newtest;
xfs_freeze -u /mnt/newtest works safely and doesn't produce lockdep warnings.

(XFS unlocks the semaphore from a different task, by design.  The mutex
code warns about this)

Signed-off-by: Dave Chinner <dgc@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-11 18:18:21 -08:00
Linus Torvalds 46d2277c79 Clean up and make try_to_free_buffers() not race with dirty pages
This is preparatory work in our continuing saga on some hard-to-trigger
file corruption with shared writable mmap() after the dirty page
tracking changes (commit d08b3851da etc)
were merged.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-21 09:04:31 -08:00
Andrew Morton e08748ce01 [PATCH] io-accounting: write-cancel accounting
Account for the number of byte writes which this process caused to not happen
after all.

Cc: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: David Wright <daw@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:41 -08:00
Andrew Morton 55e829af06 [PATCH] io-accounting: write accounting
Accounting writes is fairly simple: whenever a process flips a page from clean
to dirty, we accuse it of having caused a write to underlying storage of
PAGE_CACHE_SIZE bytes.

This may overestimate the amount of writing: the page-dirtying may cause only
one buffer_head's worth of writeout.  Fixing that is possible, but probably a
bit messy and isn't obviously important.

Cc: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: David Wright <daw@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:41 -08:00
Andrew Morton 8c08540f87 [PATCH] clean up __set_page_dirty_nobuffers()
Save a tabstop in __set_page_dirty_nobuffers() and __set_page_dirty_buffers()
and a few other places.  No functional changes.

Cc: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: David Wright <daw@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:41 -08:00
Ingo Molnar 0231606785 [PATCH] hotplug CPU: clean up hotcpu_notifier() use
There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn,
prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus
generating compiler warnings of unused symbols, hence forcing people to add
#ifdefs.

the compiler can skip truly unused functions just fine:

    text    data     bss     dec     hex filename
 1624412  728710 3674856 6027978  5bfaca vmlinux.before
 1624412  728710 3674856 6027978  5bfaca vmlinux.after

[akpm@osdl.org: topology.c fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:39 -08:00
Christoph Lameter e18b890bb0 [PATCH] slab: remove kmem_cache_t
Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:25 -08:00
Jan Kara 58ff407bee [PATCH] Fix IO error reporting on fsync()
When IO error happens on metadata buffer, buffer is freed from memory and
later fsync() is called, filesystems like ext2 fail to report EIO.  We

solve the problem by introducing a pointer to associated address space into
the buffer_head.  When a buffer is removed from a list of metadata buffers
associated with an address space, IO error is transferred from the buffer to
the address space, so that fsync can later report it.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:46 -07:00
Monakhov Dmitriy 8c58165108 [PATCH] D-cache aliasing issue in __block_prepare_write
A couple of flush_dcache_page()s are missing on the I/O-error paths.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11 11:14:23 -07:00
Andrew Morton e565793386 [PATCH] grow_buffers() infinite loop fix
If grow_buffers() is for some reason passed a block number which wants to lie
outside the maximum-addressable pagecache range (PAGE_SIZE * 4G bytes) then it
will accidentally truncate `index' and will then instnatiate a page at the
wrong pagecache offset.  This causes __getblk_slow() to go into an infinite
loop.

This can happen with corrupted disks, or with software errors elsewhere.

Detect that, and handle it.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11 11:14:21 -07:00
Nick Piggin ebf7a227dd [PATCH] mm: bug in set_page_dirty_buffers
This was triggered, but not the fault of, the dirty page accounting
patches. Suitable for -stable as well, after it goes upstream.

  Unable to handle kernel NULL pointer dereference at virtual address 0000004c
  EIP is at _spin_lock+0x12/0x66
  Call Trace:
   [<401766e7>] __set_page_dirty_buffers+0x15/0xc0
   [<401401e7>] set_page_dirty+0x2c/0x51
   [<40140db2>] set_page_dirty_balance+0xb/0x3b
   [<40145d29>] __do_fault+0x1d8/0x279
   [<40147059>] __handle_mm_fault+0x125/0x951
   [<401133f1>] do_page_fault+0x440/0x59f
   [<4034d0c1>] error_code+0x39/0x40
   [<08048a33>] 0x8048a33

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-09 19:51:18 -07:00
David Howells cf9a2ae8d4 [PATCH] BLOCK: Move functions out of buffer code [try #6]
Move some functions out of the buffering code that aren't strictly buffering
specific.  This is a precursor to being able to disable the block layer.

 (*) Moved some stuff out of fs/buffer.c:

     (*) The file sync and general sync stuff moved to fs/sync.c.

     (*) The superblock sync stuff moved to fs/super.c.

     (*) do_invalidatepage() moved to mm/truncate.c.

     (*) try_to_release_page() moved to mm/filemap.c.

 (*) Moved some related declarations between header files:

     (*) declarations for do_invalidatepage() and try_to_release_page() moved
     	 to linux/mm.h.

     (*) __set_page_dirty_buffers() moved to linux/buffer_head.h.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:31:19 +02:00
Peter Zijlstra d08b3851da [PATCH] mm: tracking shared dirty pages
Tracking of dirty pages in shared writeable mmap()s.

The idea is simple: write protect clean shared writeable pages, catch the
write-fault, make writeable and set dirty.  On page write-back clean all the
PTE dirty bits and write protect them once again.

The implementation is a tad harder, mainly because the default
backing_dev_info capabilities were too loosely maintained.  Hence it is not
enough to test the backing_dev_info for cap_account_dirty.

The current heuristic is as follows, a VMA is eligible when:
 - its shared writeable
    (vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED)
 - it is not a 'special' mapping
    (vm_flags & (VM_PFNMAP|VM_INSERTPAGE)) == 0
 - the backing_dev_info is cap_account_dirty
    mapping_cap_account_dirty(vma->vm_file->f_mapping)
 - f_op->mmap() didn't change the default page protection

Page from remap_pfn_range() are explicitly excluded because their COW
semantics are already horrid enough (see vm_normal_page() in do_wp_page()) and
because they don't have a backing store anyway.

mprotect() is taught about the new behaviour as well.  However it overrides
the last condition.

Cleaning the pages on write-back is done with page_mkclean() a new rmap call.
It can be called on any page, but is currently only implemented for mapped
pages, if the page is found the be of a VMA that accounts dirty pages it will
also wrprotect the PTE.

Finally, in fs/buffers.c:try_to_free_buffers(); remove clear_page_dirty() from
under ->private_lock.  This seems to be safe, since ->private_lock is used to
serialize access to the buffers, not the page itself.  This is needed because
clear_page_dirty() will call into page_mkclean() and would thereby violate
locking order.

[dhowells@redhat.com: Provide a page_mkclean() implementation for NOMMU]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Andrew Morton 0e1dfc66b6 [PATCH] invalidate_bdev() speedup
We can immediately bail from invalidate_bdev() if the blockdev has no
pagecache.

This solves the huge IPI storms which hald is causing on the big ia64
machines when it polls CDROM drives.

Acked-by: Jes Sorensen <jes@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:38 -07:00
Linus Torvalds 22a3e233ca Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
  Remove obsolete #include <linux/config.h>
  remove obsolete swsusp_encrypt
  arch/arm26/Kconfig typos
  Documentation/IPMI typos
  Kconfig: Typos in net/sched/Kconfig
  v9fs: do not include linux/version.h
  Documentation/DocBook/mtdnand.tmpl: typo fixes
  typo fixes: specfic -> specific
  typo fixes in Documentation/networking/pktgen.txt
  typo fixes: occuring -> occurring
  typo fixes: infomation -> information
  typo fixes: disadvantadge -> disadvantage
  typo fixes: aquire -> acquire
  typo fixes: mecanism -> mechanism
  typo fixes: bandwith -> bandwidth
  fix a typo in the RTC_CLASS help text
  smb is no longer maintained

Manually merged trivial conflict in arch/um/kernel/vmlinux.lds.S
2006-06-30 15:39:30 -07:00
Christoph Lameter b1e7a8fd85 [PATCH] zoned vm counters: conversion of nr_dirty to per zone counter
This makes nr_dirty a per zone counter.  Looping over all processors is
avoided during writeback state determination.

The counter aggregation for nr_dirty had to be undone in the NFS layer since
we summed up the page counts from multiple zones.  Someone more familiar with
NFS should probably review what I have done.

[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 11:25:35 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Christoph Hellwig f5e54d6e53 [PATCH] mark address_space_operations const
Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28 14:59:04 -07:00
Adrian Bunk b6cd0b772d [PATCH] fs/buffer.c: cleanups
- add a proper prototype for the following global function:
  - buffer_init()

- make the following needlessly global function static:
  - end_buffer_async_write()

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:38 -07:00
Jens Axboe b31dc66a54 [PATCH] Kill PF_SYNCWRITE flag
A process flag to indicate whether we are doing sync io is incredibly
ugly. It also causes performance problems when one does a lot of async
io and then proceeds to sync it. Part of the io will go out as async,
and the other part as sync. This causes a disconnect between the
previously submitted io and the synced io. For io schedulers such as CFQ,
this will cause us lost merges and suboptimal behaviour in scheduling.

Remove PF_SYNCWRITE completely from the fsync/msync paths, and let
the O_DIRECT path just directly indicate that the writes are sync
by using WRITE_SYNC instead.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
KAMEZAWA Hiroyuki ec936fc563 [PATCH] for_each_online_pgdat: renaming for_each_pgdat
Replace for_each_pgdat() with for_each_online_pgdat().

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:44:48 -08:00
Linus Torvalds 9ae21d1bb3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
  drivers/char/ftape/lowlevel/fdc-io.c: Correct a comment
  Kconfig help: MTD_JEDECPROBE already supports Intel
  Remove ugly debugging stuff
  do_mounts.c: Minor ROOT_DEV comment cleanup
  BUG_ON() Conversion in drivers/s390/block/dasd_devmap.c
  BUG_ON() Conversion in mm/mempool.c
  BUG_ON() Conversion in mm/memory.c
  BUG_ON() Conversion in kernel/fork.c
  BUG_ON() Conversion in ipc/sem.c
  BUG_ON() Conversion in fs/ext2/
  BUG_ON() Conversion in fs/hfs/
  BUG_ON() Conversion in fs/dcache.c
  BUG_ON() Conversion in fs/buffer.c
  BUG_ON() Conversion in input/serio/hp_sdc_mlc.c
  BUG_ON() Conversion in md/dm-table.c
  BUG_ON() Conversion in md/dm-path-selector.c
  BUG_ON() Conversion in drivers/isdn
  BUG_ON() Conversion in drivers/char
  BUG_ON() Conversion in drivers/mtd/
2006-03-26 09:41:18 -08:00
Badari Pulavarty b0cf2321c6 [PATCH] pass b_size to ->get_block()
Pass amount of disk needs to be mapped to get_block().  This way one can
modify the fs ->get_block() functions to map multiple blocks at the same time.

[akpm@osdl.org: performance tweak]
[akpm@osdl.org: remove unneeded assignments]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:01 -08:00
Badari Pulavarty 205f87f6b3 [PATCH] change buffer_head.b_size to size_t
Increase the size of the buffer_head b_size field (only) for 64 bit platforms.
Update some old and moldy comments in and around the structure as well.

The b_size increase allows us to perform larger mappings and allocations for
large I/O requests from userspace, which tie in with other changes allowing
the get_block_t() interface to map multiple blocks at once.

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:01 -08:00
NeilBrown 2ff28e22bd [PATCH] Make address_space_operations->invalidatepage return void
The return value of this function is never used, so let's be honest and
declare it as void.

Some places where invalidatepage returned 0, I have inserted comments
suggesting a BUG_ON.

[akpm@osdl.org: JBD BUG fix]
[akpm@osdl.org: rework for git-nfs]
[akpm@osdl.org: don't go BUG in block_invalidate_page()]
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:56:55 -08:00
NeilBrown 3978d7179d [PATCH] Make address_space_operations->sync_page return void
The only user ignores the return value, and the only instanace
(block_sync_page) always returns 0...

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:56:55 -08:00
Eric Sesterhenn e827f92355 BUG_ON() Conversion in fs/buffer.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-26 18:24:46 +02:00
OGAWA Hirofumi d25b9a1ff0 [PATCH] freeze_bdev() cleanup
freeze_bdev() uses a fsync_super() without sync_blockdev().  This patch
makes __fsync_super() and shares it.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:56 -08:00
Andrew Morton 18e79b40ed [PATCH] fsync: extract internal code
Pull the guts out of do_fsync() - we can use it elsewhere.

Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:27 -08:00
Andrew Morton 4741c9fd36 [PATCH] set_page_dirty() return value fixes
We need set_page_dirty() to return true if it actually transitioned the page
from a clean to dirty state.  This wasn't right in a couple of places.  Do a
kernel-wide audit, fix things up.

This leaves open the possibility of returning a negative errno from
set_page_dirty() sometime in the future.  But we don't do that at present.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:26 -08:00
Eric Dumazet 8a14342683 [PATCH] HOTPLUG_CPU: avoid hitting too many cachelines in recalc_bh_state()
Instead of using for_each_cpu(i), we can use for_each_online_cpu(i).

When a CPU goes offline (ie removed from online map), it might have a non
null bh_accounting.nr, so this patch adds a transfer of this counter to an
online CPU counter.

We already have a hotcpu_notifier, (function buffer_cpu_notify()), where we
can do this bh_accounting.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:26 -08:00
Paul Jackson b0196009d8 [PATCH] cpuset memory spread slab cache hooks
Change the kmem_cache_create calls for certain slab caches to support cpuset
memory spreading.

See the previous patches, cpuset_mem_spread, for an explanation of cpuset
memory spreading, and cpuset_mem_spread_slab_cache for the slab cache support
for memory spreading.

The slab caches marked for now are: dentry_cache, inode_cache, some xfs slab
caches, and buffer_head.  This list may change over time.  In particular,
other file system types that are used extensively on large NUMA systems may
want to allow for spreading their directory and inode slab cache entries.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:23 -08:00
Arjan van de Ven c039e3134a [PATCH] sem2mutex: blockdev #2
Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 07:38:11 -08:00
Christoph Lameter b20a35035f [PATCH] page migration reorg
Centralize the page migration functions in anticipation of additional
tinkering.  Creates a new file mm/migrate.c

1. Extract buffer_migrate_page() from fs/buffer.c

2. Extract central migration code from vmscan.c

3. Extract some components from mempolicy.c

4. Export pageout() and remove_from_swap() from vmscan.c

5. Make it possible to configure NUMA systems without page migration
   and non-NUMA systems with page migration.

I had to so some #ifdeffing in mempolicy.c that may need a cleanup.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 07:54:06 -08:00
Christoph Lameter 4983da07f1 [PATCH] page migration: fail if page is in a vma flagged VM_LOCKED
page migration currently simply retries a couple of times if try_to_unmap()
fails without inspecting the return code.

However, SWAP_FAIL indicates that the page is in a vma that has the
VM_LOCKED flag set (if ignore_refs ==1).  We can check for that return code
and avoid retrying the migration.

migrate_page_remove_references() now needs to return a reason why the
failure occured.  So switch migrate_page_remove_references to use -Exx
style error messages.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-14 21:43:02 -08:00
OGAWA Hirofumi e60e5c50aa [PATCH] Trivial optimization of ll_rw_block()
The ll_rw_block() needs to get ref-count only if it submits a buffer().  This
patch avoids the needless get/put of ref-count.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-03 08:32:10 -08:00
Chris Mason fc5cd582e9 [PATCH] reiserfs: zero b_private when allocating buffer heads
The b_private field in buffer heads needs to be zero filled when the
buffers are allocated.  Thanks to Nathan Scott for finding this.  It was
causing problems on systems with both XFS and reiserfs.

Signed-off-by: Chris Mason <mason@suse.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:26 -08:00
Christoph Lameter e965f9630c [PATCH] Direct Migration V9: Avoid writeback / page_migrate() method
Migrate a page with buffers without requiring writeback

This introduces a new address space operation migratepage() that may be used
by a filesystem to implement its own version of page migration.

A version is provided that migrates buffers attached to pages.  Some
filesystems (ext2, ext3, xfs) are modified to utilize this feature.

The swapper address space operation are modified so that a regular
migrate_page() will occur for anonymous pages without writeback (migrate_pages
forces every anonymous page to have a swap entry).

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Nathan Scott 01ffe339e3 Make alloc_page_buffers() initialise buffer_heads using init_buffer(),
like other routines here, to ensure buffers are correctly initialised
with respect to b_private/b_end_io.  Fixes an odd interaction between
XFS and reiserfs.

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-01-17 09:02:07 +11:00
Arjan van de Ven 858119e159 [PATCH] Unlinline a bunch of other functions
Remove the "inline" keyword from a bunch of big functions in the kernel with
the goal of shrinking it by 30kb to 40kb

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:27:06 -08:00
Randy Dunlap 16f7e0fe2e [PATCH] capable/capability.h (fs/)
fs: Use <linux/capability.h> where capable() is used.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:13 -08:00
Jes Sorensen 1b1dcc1b57 [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.

Modified-by: Ingo Molnar <mingo@elte.hu>

(finished the conversion)

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-01-09 15:59:24 -08:00
Andrew Morton 54b21a7992 [PATCH] fix possible PAGE_CACHE_SHIFT overflows
We've had two instances recently of overflows when doing

	64_bit_value = (32_bit_value << PAGE_CACHE_SHIFT)

I did a tree-wide grep of `<<.*PAGE_CACHE_SHIFT' and this is the result.

- afs_rxfs_fetch_descriptor.offset is of type off_t, which seems broken.

- jfs and jffs are limited to 4GB anyway.

- reiserfs map_block_for_writepage() takes an unsigned long for the block -
  it should take sector_t.  (It'll fail for huge filesystems with
  blocksize<PAGE_CACHE_SIZE)

- cramfs_read() needs to use sector_t (I think cramsfs is busted on large
  filesystems anyway)

- affs is limited in file size anyway.

- I generally didn't fix 32-bit overflows in directory operations.

- arm's __flush_dcache_page() is peculiar.  What if the page lies beyond 4G?

- gss_wrap_req_priv() needs checking (snd_buf->page_base)

Cc: Oleg Drokin <green@linuxhacker.ru>
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: <reiserfs-dev@namesys.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:13:54 -08:00
OGAWA Hirofumi 28fd129827 [PATCH] Fix and add EXPORT_SYMBOL(filemap_write_and_wait)
This patch add EXPORT_SYMBOL(filemap_write_and_wait) and use it.

See mm/filemap.c:

And changes the filemap_write_and_wait() and filemap_write_and_wait_range().

Current filemap_write_and_wait() doesn't wait if filemap_fdatawrite()
returns error.  However, even if filemap_fdatawrite() returned an
error, it may have submitted the partially data pages to the device.
(e.g. in the case of -ENOSPC)

<quotation>
Andrew Morton writes,

If filemap_fdatawrite() returns an error, this might be due to some
I/O problem: dead disk, unplugged cable, etc.  Given the generally
crappy quality of the kernel's handling of such exceptions, there's a
good chance that the filemap_fdatawait() will get stuck in D state
forever.
</quotation>

So, this patch doesn't wait if filemap_fdatawrite() returns the -EIO.

Trond, could you please review the nfs part?  Especially I'm not sure,
nfs must use the "filemap_fdatawrite(inode->i_mapping) == 0", or not.

Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:13:47 -08:00
OGAWA Hirofumi 05eb0b51fb [PATCH] fat: support a truncate() for expanding size (generic_cont_expand)
This patch changes generic_cont_expand(), in order to share the code
with fatfs.

  - Use vmtruncate() if ->prepare_write() returns a error.

Even if ->prepare_write() returns an error, it may already have added some
blocks.  So, this truncates blocks outside of ->i_size by vmtruncate().

  - Add generic_cont_expand_simple().

The generic_cont_expand_simple() assumes that ->prepare_write() can handle
the block boundary.  With this, we don't need to care the extra byte.

And for expanding a file size by truncate(), fatfs uses the
added generic_cont_expand_simple().

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:13:47 -08:00
Coywolf Qi Hunt 385fd4c59d [PATCH] __find_get_block_slow() cleanup
Get rid of the `int unused' parameter of __find_get_block_slow().

Signed-off-by: Coywolf Qi Hunt <qiyong@fc-cn.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:39 -08:00
Andrew Morton a3e713b5fd [PATCH] __bread oops fix
If a filesystem passes an idiotic blocksize into bread(), __getblk_slow() will
warn and will return NULL.  We have a report (from Hubert Tonneau
<hubert.tonneau@fullpliant.org>) of isofs_fill_super() doing this (passing in
a silly block size) against an unplugged CDROM drive.

But a couple of __getblk_slow() callers forgot to check for the NULL bh, hence
oops.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:27 -08:00
Jan Kara aaa4059bc2 [PATCH] ext3: Fix unmapped buffers in transaction's lists
Fix the problem (BUG 4964) with unmapped buffers in transaction's
t_sync_data list.  The problem is we need to call filesystem's own
invalidatepage() from block_write_full_page().

block_write_full_page() must call filesystem's invalidatepage().  Otherwise
following nasty race can happen:

   proc 1                                        proc 2
   ------                                        ------
- write some new data to 'offset'
  => bh gets to the transactions data list
                                              - starts truncate
                                                => i_size set to new size
- mpage_writepages()
  - ext3_ordered_writepage() to 'offset'
    - block_write_full_page()
      - page->index > end_index+1
        - block_invalidatepage()
          - discard_buffer()
            - clear_buffer_mapped()

- commit triggers and finds unmapped buffer - BOOM!

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:17 -08:00
Hugh Dickins 4c21e2f244 [PATCH] mm: split page table lock
Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with
a many-threaded application which concurrently initializes different parts of
a large anonymous area.

This patch corrects that, by using a separate spinlock per page table page, to
guard the page table entries in that page, instead of using the mm's single
page_table_lock.  (But even then, page_table_lock is still used to guard page
table allocation, and anon_vma allocation.)

In this implementation, the spinlock is tucked inside the struct page of the
page table page: with a BUILD_BUG_ON in case it overflows - which it would in
the case of 32-bit PA-RISC with spinlock debugging enabled.

Splitting the lock is not quite for free: another cacheline access.  Ideally,
I suppose we would use split ptlock only for multi-threaded processes on
multi-cpu machines; but deciding that dynamically would have its own costs.
So for now enable it by config, at some number of cpus - since the Kconfig
language doesn't support inequalities, let preprocessor compare that with
NR_CPUS.  But I don't think it's worth being user-configurable: for good
testing of both split and unsplit configs, split now at 4 cpus, and perhaps
change that to 8 later.

There is a benefit even for singly threaded processes: kswapd can be attacking
one part of the mm while another part is busy faulting.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 21:40:42 -07:00
Al Viro 27496a8c67 [PATCH] gfp_t: fs/*
- ->releasepage() annotated (s/int/gfp_t), instances updated
 - missing gfp_t in fs/* added
 - fixed misannotation from the original sweep caught by bitwise checks:
   XFS used __nocast both for gfp_t and for flags used by XFS allocator.
   The latter left with unsigned int __nocast; we might want to add a
   different type for those but for now let's leave them alone.  That,
   BTW, is a case when __nocast use had been actively confusing - it had
   been used in the same code for two different and similar types, with
   no way to catch misuses.  Switch of gfp_t to bitwise had caught that
   immediately...

One tricky bit is left alone to be dealt with later - mapping->flags is
a mix of gfp_t and error indications.  Left alone for now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28 08:16:47 -07:00
Al Viro af4ca457ea [PATCH] gfp_t: infrastructure
Beginning of gfp_t annotations:

 - -Wbitwise added to CHECKFLAGS
 - old __bitwise renamed to __bitwise__
 - __bitwise defined to either __bitwise__ or nothing, depending on
   __CHECK_ENDIAN__ being defined
 - gfp_t switched from __nocast to __bitwise__
 - force cast to gfp_t added to __GFP_... constants
 - new helper - gfp_zone(); extracts zone bits out of gfp_t value and casts
   the result to int

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28 08:16:46 -07:00
Al Viro dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00
Ingo Molnar fb1c8f93d8 [PATCH] spinlock consolidation
This patch (written by me and also containing many suggestions of Arjan van
de Ven) does a major cleanup of the spinlock code.  It does the following
things:

 - consolidates and enhances the spinlock/rwlock debugging code

 - simplifies the asm/spinlock.h files

 - encapsulates the raw spinlock type and moves generic spinlock
   features (such as ->break_lock) into the generic code.

 - cleans up the spinlock code hierarchy to get rid of the spaghetti.

Most notably there's now only a single variant of the debugging code,
located in lib/spinlock_debug.c.  (previously we had one SMP debugging
variant per architecture, plus a separate generic one for UP builds)

Also, i've enhanced the rwlock debugging facility, it will now track
write-owners.  There is new spinlock-owner/CPU-tracking on SMP builds too.
All locks have lockup detection now, which will work for both soft and hard
spin/rwlock lockups.

The arch-level include files now only contain the minimally necessary
subset of the spinlock code - all the rest that can be generalized now
lives in the generic headers:

 include/asm-i386/spinlock_types.h       |   16
 include/asm-x86_64/spinlock_types.h     |   16

I have also split up the various spinlock variants into separate files,
making it easier to see which does what. The new layout is:

   SMP                         |  UP
   ----------------------------|-----------------------------------
   asm/spinlock_types_smp.h    |  linux/spinlock_types_up.h
   linux/spinlock_types.h      |  linux/spinlock_types.h
   asm/spinlock_smp.h          |  linux/spinlock_up.h
   linux/spinlock_api_smp.h    |  linux/spinlock_api_up.h
   linux/spinlock.h            |  linux/spinlock.h

/*
 * here's the role of the various spinlock/rwlock related include files:
 *
 * on SMP builds:
 *
 *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
 *                        initializers
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
 *                        implementations, mostly inline assembly code
 *
 *   (also included on UP-debug builds:)
 *
 *  linux/spinlock_api_smp.h:
 *                        contains the prototypes for the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 *
 * on UP builds:
 *
 *  linux/spinlock_type_up.h:
 *                        contains the generic, simplified UP spinlock type.
 *                        (which is an empty structure on non-debug builds)
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  linux/spinlock_up.h:
 *                        contains the __raw_spin_*()/etc. version of UP
 *                        builds. (which are NOPs on non-debug, non-preempt
 *                        builds)
 *
 *   (included on UP-non-debug builds:)
 *
 *  linux/spinlock_api_up.h:
 *                        builds the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 */

All SMP and UP architectures are converted by this patch.

arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers.  m32r, mips, sh, sparc, have not been tested yet, but should
be mostly fine.

From: Grant Grundler <grundler@parisc-linux.org>

  Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
  Builds 32-bit SMP kernel (not booted or tested).  I did not try to build
  non-SMP kernels.  That should be trivial to fix up later if necessary.

  I converted bit ops atomic_hash lock to raw_spinlock_t.  Doing so avoids
  some ugly nesting of linux/*.h and asm/*.h files.  Those particular locks
  are well tested and contained entirely inside arch specific code.  I do NOT
  expect any new issues to arise with them.

 If someone does ever need to use debug/metrics with them, then they will
  need to unravel this hairball between spinlocks, atomic ops, and bit ops
  that exist only because parisc has exactly one atomic instruction: LDCW
  (load and clear word).

From: "Luck, Tony" <tony.luck@intel.com>

   ia64 fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjanv@infradead.org>
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 10:06:21 -07:00
Jan Kara a766223625 [PATCH] Make ll_rw_block() wait for buffer lock
Introduce new ll_rw_block() operation SWRITE meaning that block layer should
wait for the buffer lock and write-out afterwards.  Hence data in buffers at
the time of call are guaranteed to be submitted to the disk.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:55 -07:00
Coywolf Qi Hunt 736c7b808f [PATCH] alloc_buffer_head() and free_buffer_head() cleanup
Signed-off-by: Coywolf Qi Hunt <qiyong@fc-cn.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:41 -07:00
Nick Piggin a39722034a [PATCH] page_uptodate locking scalability
Use a bit spin lock in the first buffer of the page to synchronise asynch
IO buffer completions, instead of the global page_uptodate_lock, which is
showing some scalabilty problems.

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07 18:23:45 -07:00
Pekka J Enberg 687a21cee1 [PATCH] rename wakeup_bdflush to wakeup_pdflush
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28 21:20:31 -07:00
Anton Altaparmakov 152becd26e [PATCH] Bug in error recovery in fs/buffer.c::__block_prepare_write()
fs/buffer.c::__block_prepare_write() has broken error recovery.  It calls
the get_block() callback with "create = 1" and if that succeeds it
immediately clears buffer_new on the just allocated buffer (which has
buffer_new set).

The bug is that if an error occurs and get_block() returns != 0, we break
from this loop and go into recovery code.  This code has this comment:

/* Error case: */
/*
 * Zero out any newly allocated blocks to avoid exposing stale
 * data.  If BH_New is set, we know that the block was newly
 * allocated in the above loop.
 */

So the intent is obviously good in that it wants to clear just allocated
and hence not zeroed buffers.  However the code recognises allocated
buffers by checking for buffer_new being set.

Unfortunately __block_prepare_write() as discussed above already cleared
buffer_new on all allocated buffers thus no buffers will be cleared during
error recovery and old data will be leaked.

The simplest way I can see to fix this is to make the current recovery code
work by _not_ clearing buffer_new after calling get_block() in
__block_prepare_write().

We cannot safely allow buffer_new buffers to "leak out" of
__block_prepare_write(), thus we simply do a quick loop over the buffers
clearing buffer_new on each of them if it is set just before returning
"success" from __block_prepare_write().

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:34 -07:00
Oleg Nesterov dfb388bf8a [PATCH] factor out common code in sys_fsync/sys_fdatasync
This patch consolidates sys_fsync and sys_fdatasync.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:29 -07:00
Darren Hart 1ad539b2bd [PATCH] vm: try_to_free_pages unused argument
try_to_free_pages accepts a third argument, order, but hasn't used it since
before 2.6.0.  The following patch removes the argument and updates all the
calls to try_to_free_pages.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21 18:46:17 -07:00
Andrew Morton c64610ba58 [PATCH] block_read_full_page() get_block() error handling fix
If block_read_full_page() detects an error when running get_block() it will
run SetPageError(), then it will zero out the block in pagecache and will mark
the buffer_head uptodate.

So at the end of readahead we end up with a non-uptodate pagecache page which
is marked PageError.  But it has uptodate buffers.

The pagefault code will run ClearPageError, will launch readpage a second time
and block_read_full_page() will notice the uptodate buffers and will mark the
page uptodate as well.  We end up with an uptodate, !PageError page full of
zeros and the error is lost.

(It seems a little odd that filemap_nopage() runs ClearPageError().  I guess
all of this adds up to meaning that for each attempted access to the page, the
pagefault handler will retry the I/O.  Which is good and bad.  If the app is
ignoring SIGBUS for some reason we could get a lot of back-to-back I/O
errors.)

Fix it by not marking the pagecache buffer_head as uptodate if the attempt to
map that buffer to a disk block failed.

Credit-to: Qu Fuping <fs@ercist.iscas.ac.cn>

  For reporting the bug and identifying its source.

Signed-off-by: Qu Fuping <fs@ercist.iscas.ac.cn>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-17 07:59:20 -07:00
Adrian Bunk 75c96f8584 [PATCH] make some things static
This patch makes some needlessly global identifiers static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Arjan van de Ven <arjanv@infradead.org>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:47 -07:00
Andrew Morton f0fbd5fc09 [PATCH] __block_write_full_page() simplification
The `last_bh' logic probably isn't worth much.  In those situations where only
the front part of the page is being written out we will save some looping but
in the vastly more common case of an all-page writeout if just adds more code.

Nick Piggin <nickpiggin@yahoo.com.au>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:41 -07:00
Andrew Morton 05937baae9 [PATCH] __block_write_full_page speedup
Remove all those get_bh()'s and put_bh()'s by extending lock_page() to cover
the troublesome regions.

(get_bh() and put_bh() happen every time whereas contention on a page's lock
in there happens basically never).

Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:41 -07:00
Nick Piggin ad576e63e0 [PATCH] __block_write_full_page race fix
When running
	fsstress -v -d $DIR/tmp -n 1000 -p 1000 -l 2
on an ext2 filesystem with 1024 byte block size, on SMP i386 with 4096 byte
page size over loopback to an image file on a tmpfs filesystem, I would
very quickly hit
	BUG_ON(!buffer_async_write(bh));
in fs/buffer.c:end_buffer_async_write

It seems that more than one request would be submitted for a given bh
at a time.

What would happen is the following:
2 threads doing __mpage_writepages on the same page.
Thread 1 - lock the page first, and enter __block_write_full_page.
Thread 1 - (eg.) mark_buffer_async_write on the first 2 buffers.
Thread 1 - set page writeback, unlock page.
Thread 2 - lock page, wait on page writeback
Thread 1 - submit_bh on the first 2 buffers.
=> both requests complete, none of the page buffers are async_write,
   end_page_writeback is called.
Thread 2 - wakes up. enters __block_write_full_page.
Thread 2 - mark_buffer_async_write on (eg.) the last buffer
Thread 1 - finds the last buffer has async_write set, submit_bh on that.
Thread 2 - submit_bh on the last buffer.
=> oops.

So change __block_write_full_page to explicitly keep track of the last bh
we need to issue, so we don't touch anything after issuing the last
request.

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:40 -07:00
Nick Piggin f3ddbdc626 [PATCH] fix race in __block_prepare_write
Fix a race where __block_prepare_write can leak out an in-flight read
against a bh if get_block returns an error.  This can lead to the page
becoming unlocked while the buffer is locked and the read still in flight.
__mpage_writepage BUGs on this condition.

BUG sighted on a 2-way Itanium2 system with 16K PAGE_SIZE running

	fsstress -v -d $DIR/tmp -n 1000 -p 1000 -l 2

where $DIR is a new ext2 filesystem with 4K blocks that is quite
small (causing get_block to fail often with -ENOSPC).

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:40 -07:00
Andrea Arcangeli e422fd2c96 [PATCH] avoid -ENOMEM due reclaimable slab caches
This makes sure that reclaimable buffer headers and reclaimable inodes
are accounted properly during the overcommit checks.

Signed-off-by: Andrea Arcangeli <andrea@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:30 -07:00
Martin Waitz 67be2dd1ba [PATCH] DocBook: fix some descriptions
Some KernelDoc descriptions are updated to match the current code.
No code changes.

Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:59:26 -07:00
Matt Mackall cd7619d6bf [PATCH] Exterminate PAGE_BUG
Remove PAGE_BUG - repalce it with BUG and BUG_ON.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:59:01 -07:00
akpm@osdl.org d59dd4620f [PATCH] use smp_mb/wmb/rmb where possible
Replace a number of memory barriers with smp_ variants.  This means we won't
take the unnecessary hit on UP machines.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:47 -07:00
akpm@osdl.org de7d5a3b6c [PATCH] drop_buffers() oops fix
In rare situations, drop_buffers() can be called for a page which has buffers,
but no ->mapping (it was truncated, but the buffers were left behind because
ext3 was still fiddling with them).

But if there was an I/O error in a buffer_head, drop_buffers() will try to get
at the address_space and will oops.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:39 -07:00
akpm@osdl.org 76c3073a88 [PATCH] end_buffer_write_sync() avoid pointless assignments
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16 15:24:07 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
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!
2005-04-16 15:20:36 -07:00