This patch fixes what I hope is the last early ENOSPC bug left.  I did not know
that pinned extents would merge into one big extent when inserted on to the
pinned extent tree, so I was adding free space to a block group that could
possibly span multiple block groups.

This is a big issue because first that space doesn't exist in that block group,
and second we won't actually use that space because there are a bunch of other
checks to make sure we're allocating within the constraints of the block group.

This patch fixes the problem by adding the btrfs_add_free_space to
btrfs_update_pinned_extents which makes sure we are adding the appropriate
amount of free space to the appropriate block group.  Thanks much to Lee Trager
for running my myriad of debug patches to help me track this problem down.
Thank you,
Signed-off-by: Josef Bacik <jbacik@redhat.com>

fsync log replay can change the filesystem, so it cannot be delayed until
mount -o rw,remount, and it can't be forgotten entirely.  So, this patch
changes btrfs to do with reiserfs, ext3 and xfs do, which is to do the
log replay even when mounted readonly.

On a readonly device if log replay is required, the mount is aborted.

Getting all of this right had required fixing up some of the error
handling in open_ctree.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

While building large bios in writepages, btrfs may end up waiting
for other page writeback to finish if WB_SYNC_ALL is used.

While it is waiting, the bio it is building has a number of pages with the
writeback bit set and they aren't getting to the disk any time soon.  This
lowers the latencies of writeback in general by sending down the bio being
built before waiting for other pages.

The bio submission code tries to limit the total number of async bios in
flight by waiting when we're over a certain number of async bios.  But,
the waits are happening while writepages is building bios, and this can easily
lead to stalls and other problems for people calling wait_on_page_writeback.

The current fix is to let the congestion tests take care of waiting.

sync() and others make sure to drain the current async requests to make
sure that everything that was pending when the sync was started really get
to disk.  The code would drain pending requests both before and after
submitting a new request.

But, if one of the requests is waiting for page writeback to finish,
the draining waits might block that page writeback.  This changes the
draining code to only wait after submitting the bio being processed.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

The extent based waiting was using more CPU, and other fixes have helped
with the unplug storm problems.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Signed-off-by: Chris Mason <chris.mason@oracle.com>

For larger multi-device filesystems, there was logic to limit the
number of devices unplugged to just the page that was sent to our sync_page
function.

But, the code wasn't always unplugging the right device.  Since this was
just an optimization, disable it for now.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

In insert_extents(), when ret==1 and last is not zero, it should
check if the current inserted item is the last item in this batching
inserts. If so, it should just break from loop. If not, 'cur =
insert_list->next' will make no sense because the list is empty now,
and 'op' will point to an unexpectable place.

There are also some trivial fixs in this patch including one comment
typo error and deleting two redundant lines.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

For a directory tree:

/mnt/subvolA/subvolB

btrfsctl -s /mnt/subvolA/subvolB /mnt

Will create a directory loop with subvolA under subvolB.  This
commit uses the forward refs for each subvol and snapshot to error out
before creating the loop.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Subvols and snapshots can now be referenced from any point in the directory
tree.  We need to maintain back refs for them so we can find lost
subvols.

Forward refs are added so that we know all of the subvols and
snapshots referenced anywhere in the directory tree of a single subvol.  This
can be used to do recursive snapshotting (but they aren't yet) and it is
also used to detect and prevent directory loops when creating new snapshots.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Each subvolume has its own private inode number space, and so we need
to fill in different device numbers for each subvolume to avoid confusing
applications.

This commit puts a struct super_block into struct btrfs_root so it can
call set_anon_super() and get a different device number generated for
each root.

btrfs_rename is changed to prevent renames across subvols.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Before, all snapshots and subvolumes lived in a single flat directory.  This
was awkward and confusing because the single flat directory was only writable
with the ioctls.

This commit changes the ioctls to create subvols and snapshots at any
point in the directory tree.  This requires making separate ioctls for
snapshot and subvol creation instead of a combining them into one.

The subvol ioctl does:

btrfsctl -S subvol_name parent_dir

After the ioctl is done subvol_name lives inside parent_dir.

The snapshot ioctl does:

btrfsctl -s path_for_snapshot root_to_snapshot

path_for_snapshot can be an absolute or relative path.  btrfsctl breaks it up
into directory and basename components.

root_to_snapshot can be any file or directory in the FS.  The snapshot
is taken of the entire root where that file lives.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Some people are still reporting problems with early enospc.  This
will help narrown down the cause.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

In my batch delete/update/insert patch I introduced a free space leak.  The
extent that we do the original search on in free_extents is never pinned, so we
always update the block saying that it has free space, but the free space never
actually gets added to the free space tree, since op->del will always be 0 and
it's never actually added to the pinned extents tree.

This patch fixes this problem by making sure we call pin_down_bytes on the
pending extent op and set op->del to the return value of pin_down_bytes so
update_block_group is called with the right value.  This seems to fix the case
where we were getting ENOSPC when there was plenty of space available.
Signed-off-by: Josef Bacik <jbacik@redhat.com>

Inotify watch removals suck violently.

To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex.  That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount.  We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.

Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done.  Cleanup is just deactivate_super().

However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords.  That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.

We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable.  OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e.  that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().

So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong.  We had
to drop ih->mutex before we could grab ->s_umount.  So the watch
could've been gone already.

That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer.  If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address.  That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that.  Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.

So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check.  If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.

And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The file(s) below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/hwmon/lis3lv02d.c

This patch removes the said #include <version.h>.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'sh/for-2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  serial: sh-sci: Reorder the SCxTDR write after the TDxE clear.
  sh: __copy_user function can corrupt the stack in case of exception
  sh: Fixed the TMU0 reload value on resume
  sh: Don't factor in PAGE_OFFSET for valid_phys_addr_range() check.
  sh: early printk port type fix
  i2c: fix i2c-sh_mobile rx underrun
  sh: Provide a sane valid_phys_addr_range() to prevent TLB reset with PMB.
  usb: r8a66597-hcd: fix wrong data access in SuperH on-chip USB
  fix sci type for SH7723
  serial: sh-sci: fix cannot work SH7723 SCIFA
  sh: Handle fixmap TLB eviction more coherently.

* 'doc-subdirs' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs:
  Create/use more directory structure in the Documentation/ tree.

A common reason for device drivers to implement their own printk macros
is the lack of a printk prefix with the standard pr_xyz macros.
Introduce a pr_fmt() macro that is applied for every pr_xyz macro to the
format string.

The most common use of the pr_fmt macro would be to add the name of the
device driver to all pr_xyz messages in a source file.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: restrict RDMA usage

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6:
  V4L/DVB (9624): CVE-2008-5033: fix OOPS on tvaudio when controlling bass/treble
  V4L/DVB (9623): tvaudio: Improve debug msg by printing something more human
  V4L/DVB (9622): tvaudio: Improve comments and remove a unneeded prototype
  V4L/DVB (9621): Avoid writing outside shadow.bytes[] array
  V4L/DVB (9620): tvaudio: use a direct reference for chip description
  V4L/DVB (9619): tvaudio: update initial comments
  V4L/DVB (9618): tvaudio: add additional logic to avoid OOPS
  V4L/DVB (9617): tvtime: remove generic_checkmode callback
  V4L/DVB (9616): tvaudio: cleanup - group all callbacks together
  V4L/DVB (9615): tvaudio: instead of using a magic number, use ARRAY_SIZE
  V4L/DVB (9613): tvaudio: fix a memory leak

* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
  [S390] fix s390x_newuname
  [S390] dasd: log sense for fatal errors
  [S390] cpu topology: fix locking
  [S390] cio: Fix refcount after moving devices.
  [S390] ftrace: fix kernel stack backchain walking
  [S390] ftrace: disable tracing on idle psw
  [S390] lockdep: fix compile bug
  [S390] kvm_s390: Fix oops in virtio device detection with "mem="
  [S390] sclp: emit error message if assign storage fails
  [S390] Fix range for add_active_range() in setup_memory()

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] dpt_i2o: fix transferred data length for scsi_set_resid()
  [SCSI] scsi_error regression: Fix idempotent command handling
  [SCSI] zfcp: Fix hexdump data in s390dbf traces
  [SCSI] zfcp: fix erp timeout cleanup for port open requests
  [SCSI] zfcp: Wait for port scan to complete when setting adapter online
  [SCSI] zfcp: Fix cast warning
  [SCSI] zfcp: Fix request list handling in error path
  [SCSI] zfcp: fix mempool usage for status_read requests
  [SCSI] zfcp: fix req_list_locking.
  [SCSI] zfcp: Dont clear reference from SCSI device to unit
  [SCSI] qla2xxx: Update version number to 8.02.01-k9.
  [SCSI] qla2xxx: Return a FAILED status when abort mailbox-command fails.
  [SCSI] qla2xxx: Do not honour max_vports from firmware for 2G ISPs and below.
  [SCSI] qla2xxx: Use pci_disable_rom() to manipulate PCI config space.
  [SCSI] qla2xxx: Correct Atmel flash-part handling.
  [SCSI] megaraid: fix mega_internal_command oops

This reverts commit e51af663, which was
wrongly hoovered up and submitted about a month after a better fix had
already been merged.

The better fix is commit cbda1ba8
("PCI/iommu: blacklist DMAR on Intel G31/G33 chipsets"), where we do
this blacklisting based on the DMI identification for the offending
motherboard, since sometimes this chipset (or at least a chipset with
the same PCI ID) apparently _does_ actually have an IOMMU.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Hugh Dickins reported show_page_path() is buggy and unsafe because

 - lack dput() against d_find_alias()
 - don't concern vma->vm_mm->owner == NULL
 - lack lock_page()

it was only for debugging, so rather than trying to fix it, just remove
it now.
Reported-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
CC: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

m68k allmodconfig:

| drivers/misc/c2port/core.c: In function 'c2port_reset':
| drivers/misc/c2port/core.c:73: error: dereferencing pointer to incomplete type
| drivers/misc/c2port/core.c: In function 'c2port_strobe_ck':
| drivers/misc/c2port/core.c:91: error: dereferencing pointer to incomplete type

Include <linux/sched.h> to fix it, as m68k's local_irq_enable() needs to know
about struct task_struct.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

commit 69961c37 ("[PATCH] m68k/Atari:
Interrupt updates") added a BUG_ON() with an incorrect upper bound
comparison, which causes an early crash on VME boards, where IRQ_USER is
8, cnt is 192 and NR_IRQS is 200.
Reported-by: Stephen N Chivers <schivers@csc.com.au>
Tested-by: Kars de Jong <jongk@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  libata: improve phantom device detection

We don't want to get rid of the futexes just at exit() time, we want to
drop them when doing an execve() too, since that gets rid of the
previous VM image too.

Doing it at mm_release() time means that we automatically always do it
when we disassociate a VM map from the task.

Reported-by: pageexec@freemail.hu
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Alex Efros <powerman@powerman.name>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dpt_i2o.c::adpt_i2o_to_scsi() reads the value at (reply+5) which
should contain the length in bytes of the transferred data. This
would be correct if reply was a u32 *. However it is a void * here,
so we need to read the value at (reply+20) instead.

The value at (reply+5) is usually 0xff0000, which is apparently
'large enough' and didn't cause any trouble until 2.6.27 where

commit 427e59f0
Author: James Bottomley <James.Bottomley@HansenPartnership.com>
Date:   Sat Mar 8 18:24:17 2008 -0600

    [SCSI] make use of the residue value

caused this to become visible through e.g. iostat -x .
Signed-off-by: Miquel van Smoorenburg <mikevs@xs4all.net>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Currently libata uses four methods to detect device presence.

1. PHY status if available.
2. TF register R/W test (only promotes presence, never demotes)
3. device signature after reset
4. IDENTIFY failure detection in SFF state machine

Combination of the above works well in most cases but recently there
have been a few reports where a phantom device causes unnecessary
delay during probe.  In both cases, PHY status wasn't available.  In
one case, it passed #2 and #3 and failed IDENTIFY with ATA_ERR which
didn't qualify as #4.  The other failed #2 but as it passed #3 and #4,
it still caused failure.

In both cases, phantom device reported diagnostic failure, so these
cases can be safely worked around by considering any !ATA_DRQ IDENTIFY
failure as NODEV_HINT if diagnostic failure is set.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

linux-next:

Make 9p's RDMA option depend on INET since it uses Infiniband rdma_*
functions and that code depends on INET.  Otherwise 9p can try to
use symbols which don't exist.

ERROR: "rdma_destroy_id" [net/9p/9pnet_rdma.ko] undefined!
ERROR: "rdma_connect" [net/9p/9pnet_rdma.ko] undefined!
ERROR: "rdma_create_id" [net/9p/9pnet_rdma.ko] undefined!
ERROR: "rdma_create_qp" [net/9p/9pnet_rdma.ko] undefined!
ERROR: "rdma_resolve_route" [net/9p/9pnet_rdma.ko] undefined!
ERROR: "rdma_disconnect" [net/9p/9pnet_rdma.ko] undefined!
ERROR: "rdma_resolve_addr" [net/9p/9pnet_rdma.ko] undefined!

I used an if/endif block so that the menu items would remain
presented together.

Also correct an article adjective.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

Create Documentation/blockdev/ sub-directory and populate it.
Populate the Documentation/serial/ sub-directory.
Move MSI-HOWTO.txt to Documentation/PCI/.
Move ioctl-number.txt to Documentation/ioctl/.
Update all relevant 00-INDEX files.
Update all relevant Kconfig files and source files.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>

The uname system call for 64 bit compares current->personality without
masking the upper 16 bits. If e.g. READ_IMPLIES_EXEC is set the result
of a uname system call will always be s390x even if the process uses
the s390 personality.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The logging of sense data for fatal errors was accidentally removed
during Hyper PAV implementation.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

cpu_coregroup_map used to grab a mutex on s390 since it was only
called from process context.
Since c7c22e4d "block: add support
for IO CPU affinity" this is not true anymore.
It now also gets called from softirq context.

To prevent possible deadlocks change this in architecture code and
use a spinlock instead of a mutex.

Cc: stable@kernel.org
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

In ccw_device_move_to_orphanage(), a replacing ccw_device
is searched via get_{disc,orphaned}_ccwdev_by_dev_id()
which obtain a reference on the returned ccw_device.
This reference must be given up again after the device
has been moved to its new parent.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

With CONFIG_IRQSOFF_TRACER the trace_hardirqs_off() function includes
a call to __builtin_return_address(1). But we calltrace_hardirqs_off()
from early entry code. There we have just a single stack frame.
So this results in a kernel stack backchain walk that would walk beyond
the kernel stack. Following the NULL terminated backchain this results
in a lowcore read access.

To fix this we simply call trace_hardirqs_off_caller() and pass the
current instruction pointer.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Disable tracing on idle psw. Otherwise it would give us huge
preempt off times for idle. Which is rather pointless.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>