Work around problems in the writeback code to force out writebacks in
larger chunks than just 4mb, which is just too small.  This also works
around limitations in the ext4 block allocator, which can't allocate
more than 2048 blocks at a time.  So we need to defeat the round-robin
characteristics of the writeback code and try to write out as many
blocks in one inode before allowing the writeback code to move on to
another inode.  We add a a new per-filesystem tunable,
max_writeback_mb_bump, which caps this to a default of 128mb per
inode.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

The hueristic was designed to avoid using locality group preallocation
when writing the last segment of a closed file.  Fix it by move
setting size to the maximum of size and isize until after we check
whether size == isize.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This allows the user to see what filesystem was involved with a
particular ext4_da_writepage() error.  Also, use KERN_CRIT which is
more appropriate than KERN_EMERG.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

* 'writeback' of git://git.kernel.dk/linux-2.6-block:
  writeback: writeback_inodes_sb() should use bdi_start_writeback()
  writeback: don't delay inodes redirtied by a fast dirtier
  writeback: make the super_block pinning more efficient
  writeback: don't resort for a single super_block in move_expired_inodes()
  writeback: move inodes from one super_block together
  writeback: get rid to incorrect references to pdflush in comments
  writeback: improve readability of the wb_writeback() continue/break logic
  writeback: cleanup writeback_single_inode()
  writeback: kupdate writeback shall not stop when more io is possible
  writeback: stop background writeback when below background threshold
  writeback: balance_dirty_pages() shall write more than dirtied pages
  fs: Fix busyloop in wb_writeback()

Pointless to iterate other devices looking for a super, when
we have a bdi mapping.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Debug traces show that in per-bdi writeback, the inode under writeback
almost always get redirtied by a busy dirtier.  We used to call
redirty_tail() in this case, which could delay inode for up to 30s.

This is unacceptable because it now happens so frequently for plain cp/dd,
that the accumulated delays could make writeback of big files very slow.

So let's distinguish between data redirty and metadata only redirty.
The first one is caused by a busy dirtier, while the latter one could
happen in XFS, NFS, etc. when they are doing delalloc or updating isize.

The inode being busy dirtied will now be requeued for next io, while
the inode being redirtied by fs will continue to be delayed to avoid
repeated IO.

CC: Jan Kara <jack@suse.cz>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Dave Chinner <david@fromorbit.com>
CC: Chris Mason <chris.mason@oracle.com>
CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Currently we pin the inode->i_sb for every single inode. This
increases cache traffic on sb->s_umount sem. Lets instead
cache the inode sb pin state and keep the super_block pinned
for as long as keep writing out inodes from the same
super_block.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If we only moved inodes from a single super_block to the temporary
list, there's no point in doing a resort for multiple super_blocks.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

__mark_inode_dirty adds inode to wb dirty list in random order. If a disk has
several partitions, writeback might keep spindle moving between partitions.
To reduce the move, better write big chunk of one partition and then move to
another. Inodes from one fs usually are in one partion, so idealy move indoes
from one fs together should reduce spindle move. This patch tries to address
this. Before per-bdi writeback is added, the behavior is write indoes
from one fs first and then another, so the patch restores previous behavior.
The loop in the patch is a bit ugly, should we add a dirty list for each
superblock in bdi_writeback?

Test in a two partition disk with attached fio script shows about 3% ~ 6%
improvement.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

And throw some comments in there, too.
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Make the if-else straight in writeback_single_inode().
No behavior change.

Cc: Jan Kara <jack@suse.cz>
Cc: Michael Rubin <mrubin@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Fix the kupdate case, which disregards wbc.more_io and stop writeback
prematurely even when there are more inodes to be synced.

wbc.more_io should always be respected.

Also remove the pages_skipped check. It will set when some page(s) of some
inode(s) cannot be written for now. Such inodes will be delayed for a while.
This variable has nothing to do with whether there are other writeable inodes.

CC: Jan Kara <jack@suse.cz>
CC: Dave Chinner <david@fromorbit.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Treat bdi_start_writeback(0) as a special request to do background write,
and stop such work when we are below the background dirty threshold.

Also simplify the (nr_pages <= 0) checks. Since we already pass in
nr_pages=LONG_MAX for WB_SYNC_ALL and background writes, we don't
need to worry about it being decreased to zero.
Reported-by: Richard Kennedy <richard@rsk.demon.co.uk>
CC: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Some filesystem may choose to write much more than ratelimit_pages
before calling balance_dirty_pages_ratelimited_nr(). So it is safer to
determine number to write based on real number of dirtied pages.

Otherwise it is possible that
  loop {
    btrfs_file_write():     dirty 1024 pages
    balance_dirty_pages():  write up to 48 pages (= ratelimit_pages * 1.5)
  }
in which the writeback rate cannot keep up with dirty rate, and the
dirty pages go all the way beyond dirty_thresh.

The increased write_chunk may make the dirtier more bumpy.
So filesystems shall be take care not to dirty too much at
a time (eg. > 4MB) without checking the ratelimit.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If all inodes are under writeback (e.g. in case when there's only one inode
with dirty pages), wb_writeback() with WB_SYNC_NONE work basically degrades
to busylooping until I_SYNC flags of the inode is cleared. Fix the problem by
waiting on I_SYNC flags of an inode on b_more_io list in case we failed to
write anything.
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh_mobile_ceu_camera: fix compile breakage, caused by a bad merge
  sh: Add support DMA Engine to SH7780
  sh: Add support DMA Engine to SH7722
  sh: enable onenand support in kfr2r09 defconfig.
  sh: update defconfigs.
  sh: add FSI driver support for ms7724se
  sh: Fix up uninitialized variable use caught by gcc 4.4.
  sh: Handle unaligned 16-bit instructions on SH-2A.
  sh: mach-ecovec24: Add active low setting for sh_eth
  sh: includecheck fix: dwarf.c

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] Add support for the Avionic Design Xanthos watchdog timer.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (94 commits)
  genetlink: fix netns vs. netlink table locking (2)
  3c59x: Get rid of "Trying to free already-free IRQ"
  tunnel: eliminate recursion field
  ems_pci: fix size of CAN controllers BAR mapping for CPC-PCI v2
  net: fix htmldocs sunrpc, clnt.c
  Phonet: error on broadcast sending (unimplemented)
  Phonet: fix race for port number in concurrent bind()
  pktgen: better scheduler friendliness
  pktgen: T_TERMINATE flag is unused
  ipv4: check optlen for IP_MULTICAST_IF option
  ath9k: Initialize txgain and rxgain for newer AR9287 chipsets.
  iwlagn: fix panic in iwl{5000,4965}_rx_reply_tx
  ath9k: Fix RFKILL bugs
  drivers/net/wireless: Use usb_endpoint_dir_out
  cfg80211: don't overwrite privacy setting
  wl12xx: fix kconfig/link errors
  rt2x00: fix the definition of rt2x00crypto_rx_insert_iv
  iwlwifi: reduce noise when skb allocation fails
  iwlwifi: do not send sync command while holding spinlock
  mac80211: fix DTIM setting
  ...

This patch adds support for the watchdog timer on Avionic Design Xanthos
boards.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

* 'for-linus' of git://www.linux-m32r.org/git/takata/linux-2.6_dev:
  m32r: Cleanup linker script using new linker script macros.
  m32r: Move the spi_stack_top and spu_stack_top into .init.data section.
  m32r: Remove unused .altinstructions and .exit.* code from linker script.
  m32r: Move GET_THREAD_INFO definition out of asm/thread_info.h.
  m32r: Define THREAD_SIZE only once.
  m32r: make PAGE_SIZE available to assembly.

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  Fix build of cpm_uart due to core changes
  powerpc/8xx: Fix regression introduced by cache coherency rewrite
  powerpc/4xx: Fix erroneous xmon warning on PowerPC 4xx
  powerpc/mm: Fix 40x and 8xx vs. _PAGE_SPECIAL
  powerpc: Cleanup linker script using new linker script macros.
  powerpc: Fix ibm,client-architecture-support printout
  powerpc: Increase NODES_SHIFT on 64bit from 4 to 8
  powerpc/perf_counter: Fix vdso detection
  powerpc: Move 64bit heap above 1TB on machines with 1TB segments
  powerpc: Change archdata dma_data to a union
  powerpc: Rename get_dma_direct_offset get_dma_offset
  powerpc/mm: Remove duplicated #include
  powerpc/book3e-64: Remove duplicated #include
  powerpc: Check for unsupported relocs when using CONFIG_RELOCATABLE
  powerpc/pmc: Don't access lppaca on Book3E
  powerpc: kmalloc failure ignored in vio_build_iommu_table()
  hvc_console: Provide (un)locked version for hvc_resize()

Ignore the address parameter given to NOMMU mmap() as it is a hint, rather
than giving an error if it's non-zero.  MAP_FIXED still gets an error.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The NOMMU fallback for is_vmalloc_or_module_addr() should be static inline,
not just static, in linux/mm.h.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix MAP_PRIVATE mmap() of files and devices where the data in the backing store
might be mapped directly.  Use the BDI_CAP_MAP_DIRECT capability flag to govern
whether or not we should be trying to map a file directly.  This can be used to
determine whether or not a region has been filled in at the point where we call
do_mmap_shared() or do_mmap_private().

The BDI_CAP_MAP_DIRECT capability flag is cleared by validate_mmap_request() if
there's any reason we can't use it.  It's also cleared in do_mmap_pgoff() if
f_op->get_unmapped_area() fails.

Without this fix, attempting to run a program from a RomFS image on a
non-mappable MTD partition results in a BUG as the kernel attempts XIP, and
this can be caught in gdb:

Program received signal SIGABRT, Aborted.
0xc005dce8 in add_nommu_region (region=<value optimized out>) at mm/nommu.c:547
(gdb) bt
#0  0xc005dce8 in add_nommu_region (region=<value optimized out>) at mm/nommu.c:547
#1  0xc005f168 in do_mmap_pgoff (file=0xc31a6620, addr=<value optimized out>, len=3808, prot=3, flags=6146, pgoff=0) at mm/nommu.c:1373
#2  0xc00a96b8 in elf_fdpic_map_file (params=0xc33fbbec, file=0xc31a6620, mm=0xc31bef60, what=0xc0213144 "executable") at mm.h:1145
#3  0xc00aa8b4 in load_elf_fdpic_binary (bprm=0xc316cb00, regs=<value optimized out>) at fs/binfmt_elf_fdpic.c:343
#4  0xc006b588 in search_binary_handler (bprm=0x6, regs=0xc33fbce0) at fs/exec.c:1234
#5  0xc006c648 in do_execve (filename=<value optimized out>, argv=0xc3ad14cc, envp=0xc3ad1460, regs=0xc33fbce0) at fs/exec.c:1356
#6  0xc0008cf0 in sys_execve (name=<value optimized out>, argv=0xc3ad14cc, envp=0xc3ad1460) at arch/frv/kernel/process.c:263
#7  0xc00075dc in __syscall_call () at arch/frv/kernel/entry.S:897

Note that this fix does the following commit differently:

	commit a190887b
	Author: David Howells <dhowells@redhat.com>
	Date:   Sat Sep 5 11:17:07 2009 -0700
	nommu: fix error handling in do_mmap_pgoff()
Reported-by: Graff Yang <graff.yang@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Flash mappings for the MB93090-MB00 evaluation motherboard.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Note that .data.page_aligned and .data.cacheline_aligned are now after
_data; it was probably a bug that they were before it.

Also, some explicit ALIGN(8)'s between various initcall sections were
removed; this should be harmless as the implicit alignment of
initcall_t was already 8.
Signed-off-by: Geoffrey Thomas <geofft@ksplice.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alpha is the only architecture that uses the section name
.data.init_thread instead of .data.init_task.  So convert alpha to use
.data.init_task like everything else.

.data.init_task does not need a separate output section; this change
also moves it into the .data output section.
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Richard Henderson <rth@twiddle.net>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>