Some callers of btrfs_ordered_update_i_size can now pass in
a NULL for the ordered extent to update against.  This makes
sure we properly align the offset they pass in when deciding
how much to bump the on disk i_size.

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

iput() can trigger new transactions if we are dropping the
final reference, so calling it in btrfs_commit_transaction
may end up deadlock. This patch adds delayed iput to avoid
the issue.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

There are some cases file extents are inserted without involving
ordered struct. In these cases, we update disk_i_size directly,
without checking pending ordered extent and DELALLOC bit. This
patch extends btrfs_ordered_update_i_size() to handle these cases.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix file clone ioctl for bookend extents
  Btrfs: fix uninit compiler warning in cow_file_range_nocow
  Btrfs: constify dentry_operations
  Btrfs: optimize back reference update during btrfs_drop_snapshot
  Btrfs: remove negative dentry when deleting subvolumne
  Btrfs: optimize fsync for the single writer case
  Btrfs: async delalloc flushing under space pressure
  Btrfs: release delalloc reservations on extent item insertion
  Btrfs: delay clearing EXTENT_DELALLOC for compressed extents
  Btrfs: cleanup extent_clear_unlock_delalloc flags
  Btrfs: fix possible softlockup in the allocator
  Btrfs: fix deadlock on async thread startup

This patch fixes an issue with the delalloc metadata space reservation
code.  The problem is we used to free the reservation as soon as we
allocated the delalloc region.  The problem with this is if we are not
inserting an inline extent, we don't actually insert the extent item until
after the ordered extent is written out.  This patch does 3 things,

1) It moves the reservation clearing stuff into the ordered code, so when
we remove the ordered extent we remove the reservation.
2) It adds a EXTENT_DO_ACCOUNTING flag that gets passed when we clear
delalloc bits in the cases where we want to clear the metadata reservation
when we clear the delalloc extent, in the case that we do an inline extent
or we invalidate the page.
3) It adds another waitqueue to the space info so that when we start a fs
wide delalloc flush, anybody else who also hits that area will simply wait
for the flush to finish and then try to make their allocation.

This has been tested thoroughly to make sure we did not regress on
performance.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Use filemap_fdatawrite_range and filemap_fdatawait_range instead of
local copies of the functions.  For filemap_fdatawait_range that
also means replacing the awkward old wait_on_page_writeback_range
calling convention with the regular filemap byte offsets.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Conflicts:
	fs/btrfs/super.c

It's only set, it's never checked. Kill it.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Btrfs writes go through delalloc to the data=ordered code.  This
makes sure that all of the data is on disk before the metadata
that references it.  The tracking means that we have to make sure
each page in an extent is fully written before we add that extent into
the on-disk btree.

This was done in the past by setting the EXTENT_ORDERED bit for the
range of an extent when it was added to the data=ordered code, and then
clearing the EXTENT_ORDERED bit in the extent state tree as each page
finished IO.

One of the reasons we had to do this was because sometimes pages are
magically dirtied without page_mkwrite being called.  The EXTENT_ORDERED
bit is checked at writepage time, and if it isn't there, our page become
dirty without going through the proper path.

These bit operations make for a number of rbtree searches for each page,
and can cause considerable lock contention.

This commit switches from the EXTENT_ORDERED bit to use PagePrivate2.
As pages go into the ordered code, PagePrivate2 is set on each one.
This is a cheap operation because we already have all the pages locked
and ready to go.

As IO finishes, the PagePrivate2 bit is cleared and the ordered
accoutning is updated for each page.

At writepage time, if the PagePrivate2 bit is missing, we go into the
writepage fixup code to handle improperly dirtied pages.

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

This changes the btrfs code to find delalloc ranges in the extent state
tree to use the new state caching code from set/test bit.  It reduces
one of the biggest causes of rbtree searches in the writeback path.

test_range_bit is also modified to take the cached state as a starting
point while searching.

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