Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Introduce a new truncate calling sequence into fs/mm subsystems. Rather than
setattr > vmtruncate > truncate, have filesystems call their truncate sequence
from ->setattr if filesystem specific operations are required. vmtruncate is
deprecated, and truncate_pagecache and inode_newsize_ok helpers introduced
previously should be used.

simple_setattr is introduced for simple in-ram filesystems to implement
the new truncate sequence. Eventually all filesystems should be converted
to implement a setattr, and the default code in notify_change should go
away.

simple_setsize is also introduced to perform just the ATTR_SIZE portion
of simple_setattr (ie. changing i_size and trimming pagecache).

To implement the new truncate sequence:
- filesystem specific manipulations (eg freeing blocks) must be done in
  the setattr method rather than ->truncate.
- vmtruncate can not be used by core code to trim blocks past i_size in
  the event of write failure after allocation, so this must be performed
  in the fs code.
- convert usage of helpers block_write_begin, nobh_write_begin,
  cont_write_begin, and *blockdev_direct_IO* to use _newtrunc postfixed
  variants. These avoid calling vmtruncate to trim blocks (see previous).
- inode_setattr should not be used. generic_setattr is a new function
  to be used to copy simple attributes into the generic inode.
- make use of the better opportunity to handle errors with the new sequence.

Big problem with the previous calling sequence: the filesystem is not called
until i_size has already changed.  This means it is not allowed to fail the
call, and also it does not know what the previous i_size was. Also, generic
code calling vmtruncate to truncate allocated blocks in case of error had
no good way to return a meaningful error (or, for example, atomically handle
block deallocation).

Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The inode's i_size is not protected by the big kernel lock.  Therefore it
does not make sense to recommend taking the BKL in filesystems llseek
operations.  Instead it should use the inode's mutex or use just use
i_size_read() instead.  Add a note that this is not protecting
file->f_pos.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  squashfs: update documentation to include description of xattr layout
  squashfs: fix name reading in squashfs_xattr_get
  squashfs: constify xattr handlers
  squashfs: xattr fix sparse warnings
  squashfs: xattr_lookup sparse fix
  squashfs: add xattr support configure option
  squashfs: add new extended inode types
  squashfs: add support for xattr reading
  squashfs: add xattr id support

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: Ensure inode allocation buffers are fully replayed
  xfs: enable background pushing of the CIL
  xfs: forced unmounts need to push the CIL
  xfs: Introduce delayed logging core code
  xfs: Delayed logging design documentation
  xfs: Improve scalability of busy extent tracking
  xfs: make the log ticket ID available outside the log infrastructure
  xfs: clean up log ticket overrun debug output
  xfs: Clean up XFS_BLI_* flag namespace
  xfs: modify buffer item reference counting
  xfs: allow log ticket allocation to take allocation flags
  xfs: Don't reuse the same transaction ID for duplicated transactions.

Update Documentation/filesystems/tmpfs.txt to describe the interaction of
tmpfs mount option memory policy with tasks' cpuset mems_allowed.

Note: the mount(8) man page [in the util-linux-ng package] requires
similiar updates.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>