Currently ->get_dqblk() and ->set_dqblk() use struct fs_disk_quota which
tracks space limits and usage in 512-byte blocks. However VFS quotas
track usage in bytes (as some filesystems require that) and we need to
somehow pass this information. Upto now it wasn't a problem because we
didn't do any unit conversion (thus VFS quota routines happily stuck
number of bytes into d_bcount field of struct fd_disk_quota). Only if
you tried to use Q_XGETQUOTA or Q_XSETQLIM for VFS quotas (or Q_GETQUOTA
/ Q_SETQUOTA for XFS quotas), you got bogus results. Hardly anyone
tried this but reportedly some Samba users hit the problem in practice.
So when we want interfaces compatible we need to fix this.

We bite the bullet and define another quota structure used for passing
information from/to ->get_dqblk()/->set_dqblk. It's somewhat sad we have
to have more conversion routines in fs/quota/quota.c and another copying
of quota structure slows down getting of quota information by about 2%
but it seems cleaner than overloading e.g. units of d_bcount to bytes.

CC: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

Pull xfs update from Dave Chinner:
 "There's relatively little change in this update; it is mainly bug
  fixes, cleanups and more of the on-going libxfs restructuring and
  on-disk format header consolidation work.

  Details:
   - more on-disk format header consolidation
   - move some structures shared with userspace to libxfs
   - new per-mount workqueue to fix for deadlocks between nested loop
     mounted filesystems
   - various bug fixes for ENOSPC, stats, quota off and preallocation
   - a bunch of compiler warning fixes for set-but-unused variables
   - various code cleanups"

* tag 'xfs-for-linus-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (24 commits)
  xfs: split metadata and log buffer completion to separate workqueues
  xfs: fix set-but-unused warnings
  xfs: move type conversion functions to xfs_dir.h
  xfs: move ftype conversion functions to libxfs
  xfs: lobotomise xfs_trans_read_buf_map()
  xfs: active inodes stat is broken
  xfs: cleanup xfs_bmse_merge returns
  xfs: cleanup xfs_bmse_shift_one goto mess
  xfs: fix premature enospc on inode allocation
  xfs: overflow in xfs_iomap_eof_align_last_fsb
  xfs: fix simple_return.cocci warning in xfs_bmse_shift_one
  xfs: fix simple_return.cocci warning in xfs_file_readdir
  libxfs: fix simple_return.cocci warnings
  xfs: remove unnecessary null checks
  xfs: merge xfs_inum.h into xfs_format.h
  xfs: move most of xfs_sb.h to xfs_format.h
  xfs: merge xfs_ag.h into xfs_format.h
  xfs: move acl structures to xfs_format.h
  xfs: merge xfs_dinode.h into xfs_format.h
  xfs: catch invalid negative blknos in _xfs_buf_find()
  ...

Pull quota updates from Jan Kara:
 "Quota improvements and some minor cleanups.

  The main portion in the pull request are changes which move i_dquot
  array from struct inode into fs-private part of an inode which saves
  memory for filesystems which don't use VFS quotas"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: One function call less in udf_fill_super() after error detection
  udf: Deletion of unnecessary checks before the function call "iput"
  jbd: Deletion of an unnecessary check before the function call "iput"
  vfs: Remove i_dquot field from inode
  jfs: Convert to private i_dquot field
  reiserfs: Convert to private i_dquot field
  ocfs2: Convert to private i_dquot field
  ext4: Convert to private i_dquot field
  ext3: Convert to private i_dquot field
  ext2: Convert to private i_dquot field
  quota: Use function to provide i_dquot pointers
  xfs: Set allowed quota types
  gfs2: Set allowed quota types
  quota: Allow each filesystem to specify which quota types it supports
  quota: Remove const from function declarations
  quota: Add log level to printk

Conflicts:
	fs/xfs/xfs_iops.c

XFS traditionally sends all buffer I/O completion work to a single
workqueue. This includes metadata buffer completion and log buffer
completion. The log buffer completion requires a high priority queue to
prevent stalls due to log forces getting stuck behind other queued work.

Rather than continue to prioritize all buffer I/O completion due to the
needs of log completion, split log buffer completion off to
m_log_workqueue and move the high priority flag from m_buf_workqueue to
m_log_workqueue.

Add a b_ioend_wq wq pointer to xfs_buf to allow completion workqueue
customization on a per-buffer basis. Initialize b_ioend_wq to
m_buf_workqueue by default in the generic buffer I/O submission path.
Finally, override the default wq with the high priority m_log_workqueue
in the log buffer I/O submission path.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

The kernel compile doesn't turn on these checks by default, so it's
only when I do a kernel-user sync that I find that there are lots of
compiler warnings waiting to be fixed. Fix up these set-but-unused
warnings.

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

These are currently considered private to libxfs, but they are
widely used by the userspace code to decode, walk and check
directory structures. Hence they really form part of the external
API and as such need to bemoved to xfs_dir2.h.

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

These functions are needed in userspace for repair and mkfs to
do the right thing. Move them to libxfs so they can be easily
shared.

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

There's a case in that code where it checks for a buffer match in a
transaction where the buffer is not marked done. i.e. trying to
catch a buffer we have locked in the transaction but have not
completed IO on.

The only way we can find a buffer that has not had IO completed on
it is if it had readahead issued on it, but we never do readahead on
buffers that we have already joined into a transaction. Hence this
condition cannot occur, and buffers locked and joined into a
transaction should always be marked done and not under IO.

Remove this code and re-order xfs_trans_read_buf_map() to remove
duplicated IO dispatch and error handling code.

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

vn_active only ever gets decremented, so it has a very large
negative number.  Make it track the inode count we currently have
allocated properly so we can easily track the size of the inode
cache via tools like PCP.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>