driect-io will currently return EINVAL when the application tries to read the
final bit of the file at EOF.  (assuming the file's length is not a multiple
of the filesystem blocksize).

The 2.4 kernelwill reurn 0 (it won't read it at all).

This patch changes the 2.5 kernel to allow that block to be read.

If at the end of direct_io_worker, dio->result is non-zero then we
unconditionally copy that into the return value, potentially ignoring any I/O
errors which were accumulated into local variable `ret'.

Only do the assignment if `ret' is zero.

Patch from steve cameron <steve.cameron@hp.com>

Fix overrun if you have more than 16 attached tape drives + tape changers.
Thanks to Mike Anderson for pointing this out.

Patch from: steve cameron <steve.cameron@hp.com>

Steve sent out a nice series of 11 broken-out patches.  I have lumped them
all together.

- Makes the cciss driver compile in 2.5.60  (from tony@cantech.net.au)

- From randy.dunlap@verizon.net, fix memory leaks in cciss driver

- Allow cciss driver attached disks other than the first to be accessed.

- Zero out cylinders when zeroing out other disk info in cciss driver.

- Remove unused variable from cciss_scsi.c

- This patch makes scsi commands to tape drives have no timeouts.
  Previously the timeout was 1000 seconds, too short, and nothing good
  happens when the timeout expires.  Better to have no timeout.  e.g.  mt -f
  /dev/st0 erase may take about 2 hours 30 min on AIT 100.

- Remove unneeded cciss_scsi init code from cciss driver.

- Remove udelay in command polling routine
- extend timeout to 20 seconds (need for certain multiport storage box)
- Remove unneeded init time code in cciss_scsi.c (thus allowing removal
  of udelay in command polling code.)

- Factor out duplicated read capacity code into common routine in cciss
  driver.

- factor duplicated geometry inquiry code into common routine in cciss
  driver.

blk_congestion_wait() will currently not wait if there are no write requests
in flight.  Which is a potential problem if all the dirty data is against NFS
filesystems.

For write(2) traffic against NFS, things work nicely, because writers
throttle in nfs_wait_on_requests().  But for MAP_SHARED dirtyings we need to
avoid spinning in balance_dirty_pages().  So allow callers to fall through to
the explicit sleep in that case.

This will also fix a weird lockup which the reiser4 developers report.  In
that case they have managed to have _all_ inodes against a superblock in
locked state, yet there are no write requests in flight.  Taking a nap in
blk_congestion_wait() in this case will yield the CPU to the threads which
are trying to write out pages.

Also tune up the sleep durations in various callers - 250 milliseconds seems
rather long.

Patch from Andreas Gruenbacher <agruen@suse.de>

This patch adds trusted extended attributes.  Trusted extended attributes are
visible and accessible only to processes that have the CAP_SYS_ADMIN
capability.  Attributes in this class are used to implement mechanisms in
user space (i.e., outside the kernel) which keep information in extended
attributes to which ordinary processes have no access.  HSM is an example.

Patch from Andreas Gruenbacher <agruen@suse.de>

This adds the XATTR_KERNEL_CONTEXT extended attributes flag.  Kernel code may
use this flag to override extended attribute permission restrictions that
would otherwise be imposed on the calling process.

Patch from Andreas Gruenbacher <agruen@suse.de>

This adds flags parameters to the getxattr, listxattr, and removexattr inode
operations.  This is in preparation for the next patch, which allows
in-kernel code (i.e., modules) to override extended attribute permission
restrictions (which in turn is used by HSM implementations and the like).

Patch from Andreas Gruenbacher <agruen@suse.de>

This patch fixes a bug in the ext2 and ext3 listxattr operation: Even if
an attribute is hidden from the user, the terminating NULL character was
included in the listxattr result. After the patch this doesn't happen
anymore.

from Andreas Gruenbacher

Patch from Maneesh Soni <maneesh@in.ibm.com>, Dipankar Sarma
<dipankar@in.ibm.com> and probably others.


This patch provides dcache_lock free d_lookup() using RCU. Al pointed
races with d_move and lockfree d_lookup() while concurrent rename is
going on. We tested this with a test doing million renames
each in 50 threads on 50 different ramfs filesystems. And simultaneously
running millions of "ls". The tests were done on 4-way SMP box.

1. Lookup going to a different bucket as the current dentry is
   moved to a different bucket due to rename. This is solved by
   having a list_head pointer in the dentry structure which points
   to the bucket head it belongs. The bucket pointer is updated when the
   dentry is added to the hash chain. Lookup checks if the current
   dentry belongs to a different bucket, the cached lookup is
   failed and real lookup will be done. This condition occured nearly
   about 100 times during the heavy_rename test.

2. Lookup has got the dentry it is looking and it is comparing
   various keys and meanwhile a rename operation moves the dentry.
   This is solved by using a per dentry counter (d_move_count) which
   is updated at the end of d_move. Lookup takes a snapshot of the
   d_move_count before comparing the keys and once the comparision
   succeeds, it takes the per dentry lock to check the d_move_count
   again. If move_count differs, then dentry is moved (or renamed)
   and the lookup is failed.

3. There can be a theoritical race when a dentry keeps coming back
   to original bucket due to double moves. Due to this lookup may
   consider that it has never moved and can end up in a infinite loop.
   This is solved by using a loop_counter which is compared with a
   approximate maximum number of dentries per bucket. This never got
   hit during the heavy_rename test.

4. There is one more change regarding the loop termintaion condition
   in d_lookup, now the next hash pointer is compared with the current
   dentries bucket pointer (is_bucket()).

5. memcmp() in d_lookup() can go out of bounds if name pointer and length
   fields are not consistent. For this we used a pointer to qstr to keep
   length and name pointer in one structre.

We also tried solving these by using a rwlock but it could not compete
with lockless solution.

Patch from Maneesh Soni <maneesh@in.ibm.com>

Revert the fast-walk dcache code in preparation for dcache_rcu.

Patch from Joakim Tjernlund <joakim.tjernlund@lumentis.se>

I did the optimizations in the crc32 patch Brian Murphy submitted a while ago.
Now I have cleaned it up a little and made some more optimizations.

gcc is quite bad at loop optimizations (at least for PPC) so I have
rewritten them to make gcc to generate better code. Even recent gcc's(3.2.x) produces
better code.

Also reduced the unrolling since it did not make a noticeable difference.

When ext3_writepage races with truncate, block_write_full_page() will see
that the page is outside i_size and will bale out with -EIO.  But
ext3_writepage() will ignore this and will proceed to add the buffers to the
transaction.

Later, kjournald tries to write them out and goes BUG() because those buffers
are not mapped to disk.

The fix is to not attach the buffers to the transaction in ext3_writepage()
if block_write_full_page() failed.

So far so good, but that page now has dirty, unmapped buffers (the buffers
were attached in a dirty state by ext3_writepage()).  So teach
block_write_full_page() to clean the buffers against the page if it is wholly
outside i_size.

(A simpler fix to all of this mught be to just bale out of ext3_writepage()
if the page is outside i_size.  But that is racy against
block_write_full_page()'s subsequent execution of the same comparison).

Patch from: Oleg Drokin <green@namesys.com>

It moves all the arg checking code from the start of generic_file_aio_write()
into a standalone function, so other filesystems can avoid having to
cut-n-paste them.

The new function is exported to modules, and also inlined in filemap.c so
that the current filesystems are unaffected.  If someone is using ext2 and
reiserfs at the same time, they lose a bit of icache.

Patch from Oleg Drokin <green@namesys.com>

Move these already-inline functions to a header file so that filesystems can
reuse them.  For the reiserfs_file_write patch.

Patch from: Zwane Mwaikambo <zwane@holomorphy.com>

Considering that smp_call_function isn't allowed to hold a lock reference and
within smp_call_function we lock and unlock call_lock thus triggering a
preempt point.  Therefore we can't guarantee that we'll be on the same
processor when we hit do_flush_tlb_all_local.

void flush_tlb_all(void)
{
	smp_call_function (flush_tlb_all_ipi,0,1,1);

	do_flush_tlb_all_local();
}

...

smp_call_function()
{
	spin_lock(call_lock);
	...
	spin_unlock(call_lock);
	<preemption point>
}

...

do_flush_tlb_all_local() - possibly not executing on same processor
anymore.

I'm getting a build error:

	fs/jfs/super.c: In function `jfs_fill_super':
	fs/jfs/super.c:335: parse error before `)'

and it doesn't happen with gcc-3.2.x.

Taking out the file-n-line fixes it up.  This patch was acked by shaggy.

Robbie Williamson found some bugs in the mandatory locking implementation.
This patch fixes all the problems he found:

 - Fix null pointer dereference caused by sys_truncate() passing a null filp.
 - Honour the O_NONBLOCK flag when calling ftruncate()
 - Local variable `fl' wasn't being initialised correctly in
   locks_mandatory_area()
 - Don't return -ENOLCK from __posix_lock_file() when FL_ACCESS is set.

We must grab lock before checking rl->count.

bio-to-request front merging works, but request-to-request has been
broken due to a bit too much copy'n pasting.

Cleaner fix for the ioscheduler:

- Problem with alias request, the new request gets lost.
- Must always clear merge hash in move_to_dispatch()

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

into redhat.com:/garz/repo/net-drivers-2.5

Just approving this as maintainer of i2o_scsi