Interrupt handlers won't be reentered anyway.

into tp1.ruhr-uni-bochum.de:/home/kai/kernel/v2.5/linux-2.5.isdn

This adds proper support for readv/writev in the TUN/TAP driver.

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

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

The following patch against 2.5.11 updates the orinoco driver.  As well
as miscellaneous updates to the driver core it adds a new module
supporting Prism 2.5 based PCI wireless cards, and adds a MAINTAINERS
entry for the driver.

Linus,
  During a 'make bzImage', I received a warning on ppp_generic.c that ret
wasn't initialized (also for 2.5.10). I have attached a patch that sets
ret = count, thus removing the warning. Please review for inclusion.

Regards,
Frank

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

Attached patch is a resync of previous patches sent by Ingo and I.
Specifically:

	- create new MAX_USER_RT_PRIO value
	- separate uses of MAX_RT_PRIO vs MAX_USER_RT_PRIO
	- replace use of magic numbers by above
	- additional comments

This patch to synclink.h against 2.5.11 is required
for the synclink_cs.c driver to compile.

Last remaining instances removed.

I overlooked these single line changes.  Here are next corrections
against ChangeSet 1.547:

This patch takes the BKL out of vfs_readdir() and moves it into the
individual filesystems, all 35 of them.  I have the feeling that this
wasn't done before because there are a lot of these to change and it was
a pain to find them all.  I definitely got all of those that were
defined in the in the structure declaration like this "readdir:
fs_readdir;" vxfs_readdir was assigned strangely, but I found it anyway.
I also left devfs out of this one.  Richard seems confident that devfs
has no need for the BKL.

Tue Apr 30 13:23:13 CEST 2002 ide-clean-48

This fixes the "performance" degradation partially, becouse we don't
miss that many jiffies in choose_urgent_device() anymore.  However
choose_urgent_device has to be fixed for the off by one error to don't
loop for a whole 1/100 second before submitting the next request.

- Include small declaration bits for Jens. (WIN_NOP fix in esp.)

- Fix ide-pmac to conform to the recent API changes.

- Prepare and improve the handling of the request queue. It sucks now as many
   request as possible. This is improving the performance.

- Rewrite choose_drive() to iterate explicitely over the channels and devices
    on them. It is not performance critical to iterate over this typically quite
    small array of disks and allows us to let them act on the natural entity,
    namely the channel as well as to remove the drive->next field from struct
    ata_device.  Make the device eviction code in ide_do_request() more
    intelliglible.  Add some comments explaining the reasoning behind the code
    there.

- Now finally since the code for choosing the drive which will be serviced next
    is intelliglibly it became obvious that the attempt to choose the next drive
    based on the duration of the last request was entierly bogous. (Because for
    example wakeups can take a long time, but this doesn't indicate that the
    drive is slow.) Remove this criterium and the corresponding accounting
    therefore. Threat all drives fairly right now.

Surprise surprise the overall system throughput increased :-).

- Remove the specific CONFIG_IDEDMA_PCI_WIP in favor of using the generic
   CONFIG_EXPERIMENTAL tag. (Pointed out by Vojtech Pavlik).

- Change the signature of the IRQ handler to take the request directly as a
   parameter. This doesn't blow the code up but makes it much more obvious and
   finally it's reducing the number of side effects of the hwgroup->rq field.

- A second sharp look after the above change allowed us to remove the wrq field
   from the hwgroup struct. It's just not used at all.

- Change the signature of the end_request member of struct ata_operations to
   take the request as a second argument. Similar for __ide_end_request()
   and ide_end_request().

- Remove BUG_ON() items just before ide_set_handler(). The check in
   ide_set_handler is clever enough now.

- Remove the rq subfield from ide-scsi packet structure. We have now the
   request context always in place. Same for floppy.

- Let the timer expiry function take the request as a direct argument.

Yes I know those changes are extensive. But they are a necessary step
in between for the following purposes:

- Consolidate the whole ATA/ATAPI stuff on passing a single unified request
   handling object. Because after eliminating those side effects it's far easier
   to see what's passed where.

- Minimizing the amount of side effects in the overall code. That's a good
   thing anyway and it *doesn't* cost us neither performance nor space, since
   the stack depths are small anyway here.

- Minimizing the usage of hwgroup - which should go away if possible.

Renames sync_buffers() to sync_blockdev() and removes its (never used)
second argument.

Removes fsync_no_super() in favour of direct calls to sync_blockdev().

- Fixes a performance problem - callers of
  prepare_write/commit_write, etc are locking pages, which synchronises
  them behind writeback, which also locks these pages.  Significant
  slowdowns for some workloads.

- So pages are no longer locked while under writeout.  Introduce a
  new PG_writeback and associated infrastructure to support this design
  change.

- Pages which are under read I/O still use PageLocked.  Pages which
  are under write I/O have PageWriteback() true.

  I considered creating Page_IO instead of PageWriteback, and marking
  both readin and writeout pages as PageIO().  So pages are unlocked
  during both read and write.  There just doesn't seem a need to do
  this - nobody ever needs unblocking access to a page which is under
  read I/O.

- Pages under swapout (brw_page) are PageLocked, not PageWriteback.
  So their treatment is unchangeded.

  It's not obvious that pages which are under swapout actually need
  the more asynchronous behaviour of PageWriteback.

  I was setting the swapout pages PageWriteback and unlocking them
  prior to submitting the buffers in brw_page().  This led to deadlocks
  on the exit_mmap->zap_page_range->free_swap_and_cache path.  These
  functions call block_flushpage under spinlock.  If the page is
  unlocked but has locked buffers, block_flushpage->discard_buffer()
  sleeps.  Under spinlock.  So that will need fixing if for some reason
  we want swapout to use PageWriteback.

  Kernel has called block_flushpage() under spinlock for a long time.
   It is assuming that a locked page will never have locked buffers.
  This appears to be true, but it's ugly.

- Adds new function wait_on_page_writeback().  Renames wait_on_page()
  to wait_on_page_locked() to remind people that they need to call the
  appropriate one.

- Renames filemap_fdatasync() to filemap_fdatawrite().  It's more
  accurate - "sync" implies, if anything, writeout and wait.  (fsync,
  msync) Or writeout.  it's not clear.

- Subtly changes the filemap_fdatawrite() internals - this function
  used to do a lock_page() - it waited for any other user of the page
  to let go before submitting new I/O against a page.  It has been
  changed to simply skip over any pages which are currently under
  writeback.

  This is the right thing to do for memory-cleansing reasons.

  But it's the wrong thing to do for data consistency operations (eg,
  fsync()).  For those operations we must ensure that all data which
  was dirty *at the time of the system call* are tight on disk before
  the call returns.

  So all places which care about this have been converted to do:

	filemap_fdatawait(mapping);	/* Wait for current writeback */
	filemap_fdatawrite(mapping);	/* Write all dirty pages */
	filemap_fdatawait(mapping);	/* Wait for I/O to complete */

- Fixes a truncate_inode_pages problem - truncate currently will
  block when it hits a locked page, so it ends up getting into lockstep
  behind writeback and all of the file is pointlessly written back.

  One fix for this is for truncate to simply walk the page list in the
  opposite direction from writeback.

  I chose to use a separate cleansing pass.  It is more
  CPU-intensive, but it is surer and clearer.  This is because there is
  no reason why the per-address_space ->vm_writeback and
  ->writeback_mapping functions *have* to perform writeout in
  ->dirty_pages order.  They may choose to do something totally
  different.

  (set_page_dirty() is an a_op now, so address_spaces could almost
  privatise the whole dirty-page handling thing.  Except
  truncate_inode_pages and invalidate_inode_pages assume that the pages
  are on the address_space lists.  hmm.  So making truncate_inode_pages
  and invalidate_inode_pages a_ops would make some sense).

Implements hashed waitqueues for buffer_heads.  Drops twelve bytes from
struct buffer_head.

Moves all buffer_head-related stuff out of linux/fs.h and into
linux/buffer_head.h.  buffer_head.h is currently included at the very
end of fs.h.  So it is possible to include buffer_head directly from
all .c files and remove this nested include.

Also rationalises all the set_buffer_foo() and mark_buffer_bar()
functions.  We have:

	set_buffer_foo(bh)
	clear_buffer_foo(bh)
	buffer_foo(bh)

and, in some cases, where needed:

	test_set_buffer_foo(bh)
	test_clear_buffer_foo(bh)

And that's it.

BUFFER_FNS() and TAS_BUFFER_FNS() macros generate all the above real
inline functions.  Normally not a big fan of cpp abuse, but in this
case it fits.  These function-generating macros are available to
filesystems to expand their own b_state functions.  JBD uses this in
one case.

Remove show_buffers().  It really has nothing to show any more.  just
buffermem_pages() - move that out into the callers.

There's a lot of duplication in this code.  better approach would be to
remove all the duplicated code out in the architectures and implement
generic show_memory_state().  Later.

Remove PG_skip.  Nothing is using it (the change was acked by rmk a
while back)

Removes inode.i_dirty_data_buffers.  It's no longer used - all dirty
buffers have their pages marked dirty and filemap_fdatasync() /
filemap_fdatawait() catches it all.

Updates all callers.

This required a change in JFS - it has "metapages" which
are a container around a page which holds metadata.  They
were holding these pages locked and were relying on fsync_inode_data_buffers
for writing them out.  So fdatasync() deadlocked.

I've changed JFS to not lock those pages.  Change was acked
by Dave Kleikamp <shaggy@austin.ibm.com> as the right
thing to do, but may not be complete.  Probably igrab()
against ->host is needed to pin the address_space down.

Removal of buffer_head.b_inode.  The list_emptiness of b_inode_buffers
is used to indicate whether the buffer is on an inode's
i_dirty_buffers.

Remove writeout_one_page(), waitfor_one_page() and the now-unused
generic_buffer_fdatasync().

Add new

	write_one_page(struct page *page, int wait)

which is exported to modules.  Update callers to use that.  It's only
used for IS_SYNC operations.

Removes some redundant BUG checks - trueness of PageSwapCache() implies
that page->mapping is non-NULL, and we've already checked that.