This prepares the removal of the big kernel lock from the
file locking code. We still use the BKL as long as fs/lockd
uses it and ceph might sleep, but we can flip the definition
to a private spinlock as soon as that's done.
All users outside of fs/lockd get converted to use
lock_flocks() instead of lock_kernel() where appropriate.

Based on an earlier patch to use a spinlock from Matthew
Wilcox, who has attempted this a few times before, the
earliest patch from over 10 years ago turned it into
a semaphore, which ended up being slower than the BKL
and was subsequently reverted.

Someone should do some serious performance testing when
this becomes a spinlock, since this has caused problems
before. Using a spinlock should be at least as good
as the BKL in theory, but who knows...
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMatthew Wilcox <willy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Sage Weil <sage@newdream.net>
Cc: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org

Dozen of changes in ncpfs to provide some locking other than BKL.

In readdir cache unlock and mark complete first page as last operation,
so it can be used for synchronization, as code intended.

When updating dentry name on case insensitive filesystems do at least
some basic locking...

Hold i_mutex when updating inode fields.

Push some ncp_conn_is_valid down to ncp_request.  Connection can become
invalid at any moment, and fewer error code paths to test the better.

Use i_size_{read,write} to modify file size.

Set inode's backing_dev_info as ncpfs has its own special bdi.

In ioctl unbreak ioctls invoked on filesystem mounted 'ro' - tests are
for inode writeable or owner match, but were turned to filesystem
writeable and inode writeable or owner match.  Also collect all permission
checks in single place.

Add some locking, and remove comments saying that it would be cool to
add some locks to the code.

Constify some pointers.
Signed-off-by: NPetr Vandrovec <petr@vandrovec.name>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL in ocfs2/dlmfs is used in put_super, fill_super and remount_fs
that are all three protected by the superblocks s_umount rw_semaphore.

The use in ocfs2_control_open is evidently unrelated and the function
is protected by ocfs2_control_lock.

Therefore it is safe to remove the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>

The BKL is only used in put_super and fill_super, which are both protected
by the superblocks s_umount rw_semaphore. Therefore it is safe to remove
the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>

The BKL is only used in put_super, fill_super and remount_fs that are all
three protected by the superblocks s_umount rw_semaphore. Therefore it is
safe to remove the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw2@infradead.org>

The BKL is only used in fill_super, which is protected by the superblocks
s_umount rw_semaphorei, and in fasync, which does not do anything that
could require the BKL. Therefore it is safe to remove the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net

The BKL is only used in put_super and fill_super, which are both protected
by the superblocks s_umount rw_semaphore. Therefore it is safe to remove
the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: linux-afs@lists.infradead.org
Cc: David Howells <dhowells@redhat.com>

The BKL is only used in fill_super, which is  protected by the superblocks
s_umount rw_semaphore. Therefore it is safe to remove the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: linux-usb@vger.kernel.org

autofs4 uses the BKL only to guard its ioctl operations.
This can be trivially converted to use a mutex, as we have
done with most device drivers before.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Kent <raven@themaw.net>

As in other file systems, we can replace the big kernel lock
with a private mutex in isofs. This means we can now access
multiple file systems concurrently, but it also means that
we serialize readdir and lookup across sleeping operations
which previously released the big kernel lock. This should
not matter though, as these operations are in practice
serialized through the hardware access.

The isofs_get_blocks functions now does not take any lock
any more, it used to recursively get the BKL. After looking
at the code for hours, I convinced myself that it was never
needed here anyway, because it only reads constant fields
of the inode and writes to a buffer head array that is
at this time only visible to the caller.

The get_sb and fill_super operations do not need the locking
at all because they operate on a file system that is either
about to be created or to be destroyed but in either case
is not visible to other threads.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The lock_kernel in fat_put_super is not needed because
it only protects the super block itself and we know that
no other thread can reach it because we are about to
kfree the object.

In the two fill_super functions, this converts the locking
to use lock_super like elsewhere in the fat code. This
is probably not needed either, but is consistent and puts
us on the safe side.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jan Blunck <jblunck@infradead.org>

The BKL is still used in ext2_put_super(), ext2_fill_super(), ext2_sync_fs()
ext2_remount() and ext2_write_inode(). From these calls ext2_put_super(),
ext2_fill_super() and ext2_remount() are protected against each other by
the struct super_block s_umount rw semaphore. The call in ext2_write_inode()
could only protect the modification of the ext2_sb_info through
ext2_update_dynamic_rev() against concurrent ext2_sync_fs() or ext2_remount().
ext2_fill_super() and ext2_put_super() can be left out because you need a
valid filesystem reference in all three cases, which you do not have when
you are one of these functions.

If the BKL is only protecting the modification of the ext2_sb_info it can
safely be removed since this is protected by the struct ext2_sb_info s_lock.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

After pushing down the BKL to the get_sb/fill_super operations of the
filesystems that still make usage of the BKL it is safe to remove it from
do_new_mount().

I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in remount_fs and get_sb that are both protected by
the superblocks s_umount rw_semaphore. Therefore it is safe to remove the
BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super, fill_super and remount_fs that are all
three protected by the superblocks s_umount rw_semaphore. Therefore it is
safe to remove the BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super, fill_super and remount_fs that are all
three protected by the superblocks s_umount rw_semaphore. Therefore it is
safe to remove the BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super, fill_super and remount_fs that are all
three protected by the superblocks s_umount rw_semaphore. Therefore it is
safe to remove the BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super and fill_super that are both protected by
the superblocks s_umount rw_semaphore. Therefore it is safe to remove the
BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is still used in ext4_put_super(), ext4_fill_super() and
ext4_remount(). All three calles are protected against concurrent calls by
the s_umount rw semaphore of struct super_block.

Therefore the BKL is protecting nothing in this case.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Acked-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL lock is protecting the remounting against a potential call to
ext3_put_super(). This could not happen, since this is protected by the
s_umount rw semaphore of struct super_block.

Therefore I think the BKL is protecting nothing here.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is protecting nothing than two memory allocations here.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super and fill_super that are both protected by
the superblocks s_umount rw_semaphore. Therefore it is safe to remove the
BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super and fill_super that are both protected by
the superblocks s_umount rw_semaphore. Therefore it is safe to remove the BKL
entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The BKL is only used in put_super, fill_super and remount_fs that are all
three protected by the superblocks s_umount rw_semaphore. Therefore it is
safe to remove the BKL entirely.
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.

I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.

do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.

Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.

[arnd: do not add the BKL to those file systems that already
       don't use it elsewhere]
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>

When caching is disabled on the MN10300 arch, the sys_cacheflush()
function is removed by conditional stuff in the makefiles, but is still
referred to by the syscall table.

Provide a null version that just returns 0 when caching is disabled (or
-EINVAL if the arguments are silly).
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tssk.  Apparently Al hadn't checked commit c52c2ddc ("alpha: switch
osf_sigprocmask() to use of sigprocmask()") at all. It doesn't compile.

Fixed as per suggestions from Michael Cree.
Reported-by: NMichael Cree <mcree@orcon.net.nz>
Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ahci: fix module refcount breakage introduced by libahci split

libata depends on scsi_host_template for module reference counting and
sht's should be owned by each low level driver.  During libahci split,
the sht was left with libahci.ko leaving the actual low level drivers
not reference counted.  This made ahci and ahci_platform always
unloadable even while they're being actively used.

Fix it by defining AHCI_SHT() macro in ahci.h and defining a sht for
each low level ahci driver.

stable: only applicable to 2.6.35.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NPedro Francisco <pedrogfrancisco@gmail.com>
Tested-by: NMichael Tokarev <mjt@tls.msk.ru>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
  hwmon (coretemp): Fix build breakage if SMP is undefined

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: fix pci_resource_alignment prototype

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (47 commits)
  tcp: Fix >4GB writes on 64-bit.
  net/9p: Mount only matching virtio channels
  de2104x: fix ethtool
  tproxy: check for transparent flag in ip_route_newports
  ipv6: add IPv6 to neighbour table overflow warning
  tcp: fix TSO FACK loss marking in tcp_mark_head_lost
  3c59x: fix regression from patch "Add ethtool WOL support"
  ipv6: add a missing unregister_pernet_subsys call
  s390: use free_netdev(netdev) instead of kfree()
  sgiseeq: use free_netdev(netdev) instead of kfree()
  rionet: use free_netdev(netdev) instead of kfree()
  ibm_newemac: use free_netdev(netdev) instead of kfree()
  smsc911x: Add MODULE_ALIAS()
  net: reset skb queue mapping when rx'ing over tunnel
  br2684: fix scheduling while atomic
  de2104x: fix TP link detection
  de2104x: fix power management
  de2104x: disable autonegotiation on broken hardware
  net: fix a lockdep splat
  e1000e: 82579 do not gate auto config of PHY by hardware during nominal use
  ...

Commit e40cc4bd introduced
a build breakage if CONFIG_SMP is undefined. This commit
fixes the problem.

This fix is only a workaround. For a real fix, cpu_sibling_mask() should
be defined in UP include code, eg in linux/smp.h, and asm/smp.h should not be
included directly. This fix is currently not possible because asm/smp.h defines
cpu_sibling_mask() unconditionally and is included directly from many source
files.
Reported-by: NIngo Molnar <mingo@elte.hu>
Tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Avoid 'constant_test_bit()' misoptimization due to cast to non-volatile

Fixes kernel bugzilla #16603

tcp_sendmsg() truncates iov_len to an 'int' which a 4GB write to write
zero bytes, for example.

There is also the problem higher up of how verify_iovec() works.  It
wants to prevent the total length from looking like an error return
value.

However it does this using 'int', but syscalls return 'long' (and
thus signed 64-bit on 64-bit machines).  So it could trigger
false-positives on 64-bit as written.  So fix it to use 'long'.
Reported-by: NOlaf Bonorden <bono@onlinehome.de>
Reported-by: NDaniel Büse <dbuese@gmx.de>
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The PKT_CTRL_CMD_STATUS device ioctl retrieves a pointer to a
pktcdvd_device from the global pkt_devs array.  The index into this
array is provided directly by the user and is a signed integer, so the
comparison to ensure that it falls within the bounds of this array will
fail when provided with a negative index.

This can be used to read arbitrary kernel memory or cause a crash due to
an invalid pointer dereference.  This can be exploited by users with
permission to open /dev/pktcdvd/control (on many distributions, this is
readable by group "cdrom").
Signed-off-by: NDan Rosenberg <dan.j.rosenberg@gmail.com>
[ Rather than add a cast, just make the function take the right type -Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The configuration choice for the port on which the GDB stub listens has
a default of GDBSTUB_TTYSM0, but this should be GDBSTUB_ON_TTYSM0 to
match the option.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

p9_virtio_create will only compare the the channel's tag characters
against the device name till the end of the channel's tag but not till
the end of the device name. This means that if a user defines channels
with the tags foo and foobar then he would mount foo when he requested
foonot and may mount foo when he requested foobar.

Thus it is necessary to check both string lengths against each other in
case of a successful partial string match.
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the interface is up, using ethtool breaks it because:
a) link is put down but media_timer interval is not shortened to NO_LINK
b) rxtx is stopped but not restarted

Also manual 10baseT-HD (and probably FD too - untested) mode does not work -
the link is forced up, packets are transmitted but nothing is received.
Changing CSR14 value to match documentation (not disabling link check) fixes this.
Signed-off-by: NOndrej Zary <linux@rainbow-software.org>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>