Pages under writeback are not locked.  So it is possible (and quite
legal) for a page to be under readpage() while it is still under
writeback.  For a partially uptodate page with blocksize <
PAGE_CACHE_SIZE.

When this happens, the read and write I/O completion handlers get
confused over the shared BH_Async usage and the page ends up not
getting PG_writeback cleared.  Truncate gets stuck in D state.

The patch separates the read and write I/O completion state.

It also shuffles the buffer fields around.  Putting the
commonly-accessed b_state at offset zero shrinks the kernel by a few
hundred bytes because it can be accessed with indirect addressing, not
indirect+indexed.

Set PG_launder against pages which are under VM writeback.  So page
allocators will throttle against them.

set_page_dirty() runs without the page lock.  So
__block_write_full_page() needs to be able to cope with the page's
buffers being dirtied concurrently, on another CPU.

Do this with careful ordering and a test-and-set.

Closes a small race window: testing PageWriteback() outside the page
lock introduces the possibility that page could be redirtied and have
writeback started after we've inspected PageWriteback.

When ext3 refiles journalled buffers for writeback, it is better to set the
page dirty as well as the buffer.  So the page will be written out by
VM pressure rather than by kjournald alone.

swapper_space is different.  Its pages are locked during writeout, it
uses PAGE_SIZE rather than PAGE_CACHE_SIZE.  Converting swap to look
more like the other address_spaces is a separate project.  This patch
fully restores the old swap behaviour.

- Don't dirty swapcache page buffers in set_page_dirty().

  Fixes a problem where __free_pte() runs set_page_dirty() and then
  immediately runs ClearPageDirty().  The pages ends up clean, with
  dirty buffers, and is unfreeable.

- Hence, don't mark the page clean if its buffers are clean - swap
  does not have page/buffers dirty state coherency.

The buffer state "uptodate, dirty, unmapped" is legal.  It occurs when
a mapped page with attached buffers which is over a hole is dirtied.

So discard_buffer() needs to be able to discard those buffers as well;
otherwise the page ends up clean, with dirty buffers and is unfreeable.

__delete_from_swap_cache modifies the radix tree.  We need to take the
lock for writing.

The recently-added page allocation failure warning generates a lot of
noise due to radix-tree node allocation failures.  Those messages are
not interesting.

But I think the warning is otherwise useful - "I got an allocation
failure and then it crashed" is better than "it crashed".

The patch suppresses the message for ratnode allocation failures.

 - Finish the changes from patch 53. ide_dma_actaion_t is gone now as well as
   whole hidden code paths associated with it. I hope I didn't mess too many
   things up with this, since the sheer size of the changes make them sensitive.
   (Tested on tree different host chip sets so it shouldn't be too bad...)

   Just still some minor cleanup remaining to be done in this area. The tags
   lefts there are intentional.

   In esp. the ide_dma_on method in cy82c693 looks suspicious.

   Using udma_enable in ide-cd.c, ide-floppy.c and ide-tape.c is suspicious as
   well. We have just uncovered it.

   In the next round we will concentrate on the fixes people did send me
   last time.

 - Start splitting the functions for host chip handling in to separate entities.
   This change is quite sensitive and may cause some trouble but it's for
   certain worth it anyway, because it should for example provide a much better
   infrastructure for th handling of different architectures.

Adapted from patch Bar³omiej ¯o³nierkiewicz:

 - make straight8 a flag in ata_channel instead of byte

 - don't store tables as code in drive_is_flashcard()
   and ide_xfer_verbose()

 - fix init_gendisk() (due to 2.5.13 blksize_size[] change)

 - compress region requesting/releasing
   in channel_probe() and ide_unregister()

 - clean a bit ide_setup_ports()

Start of DMA handling tratment.

 - Fix the parameters to ide_build_dmatable() to be channel and request.
   Rename it to udma_new_table(). udma will mark arch specific functions
   later.

 - Let ide_start_dma() take the request directly as an arguemnt. Rename it to
   ata_start_dma(). After realizing that the usage of the func argument of it
   was bogous and that nobody is using rwproc we where able to remove both of
   them.

 - Fix ide_destroy_dmatable() to take the channel as argument and rename it to
   udma_destroy_table(). This function should have possible architecture
   specific implementation as well at some point in time.

 - Split up the TCQ UDMA handling stuff in to proper functions. Jens must has
   been dreaming as he introduced them ;-).

into home.transmeta.com:/home/torvalds/v2.5/linux

- Remove always unused variable page from remap_pte_range().
- Fix printk in do_wp_page() so it doesn't print out an uninitialized
  variable (old_page). Add KERN_ERR log level while at it.

into home.transmeta.com:/home/torvalds/v2.5/linux

- Initialize the mftbmp address space properly now that there are more
fields in the struct address_space. This was leading to hangs and
oopses on umount since 2.5.12 because of changes to other parts of
the kernel. We probably want a kernel generic init_address_space()
function...
- Drop BKL from ntfs_readdir() after consultation with Al Viro. The
only caller of ->readdir() is vfs_readdir() which holds i_sem during
the call, and i_sem is sufficient protection against changes in the
directory inode (including ->i_size).
- Use generic_file_llseek() for directories (as opposed to
default_llseek()) as this downs i_sem instead of the BKL which is
what we now need for exclusion against ->f_pos changes considering we
no longer take the BKL in ntfs_readdir().

I found this bug in 2.5.10 first. And caused ext2 FS corruption.
We are porting Linux to PC-9801 architecture (made by NEC Japan).
It has PIO ONLY IDE I/F. So please check PIO mode too.

It was introduced in 2.5.9 and still exists in 2.5.13, and caused
superblock corruption for Andries.  This fixes it.

Andrej Lajovic observes that in kd.h the definitions of K_NUMLOCK and
K_CAPSLOCK are interchanged.  He is right (and this is the case since
1.1.54; nobody noticed because setleds.c does not use these defines).
So, here is the fix.  No kernel behaviour is changed.

xprt.c:
  Merge *_write_space() in order to fix compile warning and save space.

Cheers,
  Trond

xprt.c:
  Fix the RPC over TCP socket reconnect code.

Cheers,
  Trond

xprt.c:
  Speed up synchronous RPC over TCP calls by having the
  replies delivered by the IPV4 "bottom half", instead of
  switching to the rpciod process in order to call recvmsg().
   - Remove sock_recvmsg() interface.
   - Remove rpc_xprt_pending list and rpciod_tcp_dispatcher() interface.
   - Use the new tcp_read_sock() interface to deliver data directly
     from within tcp_data_ready().
sched.c:
   - Remove references to rpciod_tcp_dispatcher.
xprt.h:
   - New set of flags to reflect the TCP record read state.

Cheers,
  Trond

Fix silly truncate status update

i810-tco: Merge changes of the 2.4 kernel into the i810-tco module. Changes included are:
Support for 82801CA(M) chipset, timer margin needs to be > 3, support for WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT.

Merge updates from the 2.4 kernel into watchdog.h .

Update of PCI-IDS for the 82801BA(M), 82801CA(M) and 82801E I/O Controller Hub's.

i810_rng: add support for other i8xx chipsets to the Random Number Generator module.
This is being done by adding the detection of the 82801E I/O Controller Hub.

This updates 2.5.x Bluetooth subsystem and removes the EXPERIMENTAL
status of Bluetooth support.

         BlueZ Core:
                 New generic HCI connection manager.
                 Complete role switch and link policy support.
                 Security mode 1 and 3 support.
                 L2CAP service level security support.
                 HCI filter support.
                 HCI frame time-stamps.
                 SCO (voice links) support.
                 Improved HCI device unregistration (device destructors).
                 Support for L2CAP signalling frame fragmentation.
                 Improved L2CAP timeout handling.
                 New HCI ioctls for changing ACL and SCO MTU.
                 Killed HCI_MAX_DEV limit.
                 Security fixes.

         HCI USB driver:
                 Performance improvements.
                 Firmware loading support.
                 Stability fixes. URB and disconnect handling rewrite.

         HCI UART driver:
                 Support for multiple UART protocols.

         HCI PCMCIA driver:
                 Support for Nokia Bluetooth PC Cards.
                 Support for Anycom Bluetooth PC/CF Cards.

into penguin.transmeta.com:/home/penguin/torvalds/repositories/kernel/linux

Here is the patch to replace mk_pte_phys() with pfn_pte() and so creates
the counterpart to pte_pfn().

This patch removes VALID_PAGE(), as the test was always too late for
discontinous memory configuration. It is replaced with pfn_valid()/
virt_addr_valid(), which are used to test the original input value.
Other helper functions:
pte_pfn() - extract the page number from a pte
pfn_to_page()/page_to_pfn() - convert a page number to/from a page struct

into heisenberg.transvirtual.com:/tmp/fbdev-2.5

PRD_SEGMENTS was a leftover from struct ata_request an its per-command
sg tables.

 - Synchronize with Jens.  Applying tons of janitorian stuff to his TCQ
   code.  Making functions static where appropriate and so on...
   Marking the config entry for it experimental and so on.  His
   changelog:

	2.5.13 now has the generic tag support that I wrote included,
	here's an IDE TCQ that uses that.  Changes since the version
	posted for 2.5.12:

	Fix the ide_tcq_invalidate_queue() WIN_NOP usage needed to clear
	the internal queue on errors.  It was disabled in the last
	version due to the ata_request changes, it should work now.

	Remove Promise tcq disable check, it works just fine on Promise
	as long as we handle the two-drives-with-tcq case like we
	currently do.

 - Fix wrong usage of time_after in ide.c. This should cure the drive seek
   timeout problems some people where expierencing. This was clarified to me by
   Bartek, who apparently checked whatever the actual code is consistent with
   the comments in front of it. Thank you Bartlomiej Zolnierkiewicz.

   I think now that we should have time_past(xxx) in <linux/timer.h>.

 - Fix hpt34x.c compilation.

 - Minor improvements in ide-pci and some cleanups in ide-probe.c

 - Nuke some vastly outdated comments.

D'oh.  Missing commas...