Inode allocation is modified to look in other nodes allocators during
extreme out of space situations. We retry our own slot when space is freed
back to the global bitmap, or whenever we've allocated more than 1024 inodes
from another slot.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

In ocfs2_figure_merge_contig_type, we judge whether there exists
a cross extent block merge and enable it by setting CONTIG_LEFT
and CONTIG_RIGHT accordingly.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

In ocfs2_merge_rec_left, when we find the merge extent is "CONTIG_RIGHT"
with the first extent record of the next extent block, we will merge it to
the next extent block and change all the related extent blocks accordingly.

In ocfs2_merge_rec_right, when we find the merge extent is "CONTIG_LEFT"
with the last extent record of the previous extent block, we will merge
it to the prevoius extent block and change all the related extent blocks
accordingly.

As for CONTIG_LEFTRIGHT, we will handle CONTIG_RIGHT first so that when
the index is zero, the merge process will be more efficient and easier.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Simplify page cache zeroing of segments of pages through 3 functions

zero_user_segments(page, start1, end1, start2, end2)

        Zeros two segments of the page. It takes the position where to
        start and end the zeroing which avoids length calculations and
	makes code clearer.

zero_user_segment(page, start, end)

        Same for a single segment.

zero_user(page, start, length)

        Length variant for the case where we know the length.

We remove the zero_user_page macro. Issues:

1. Its a macro. Inline functions are preferable.

2. The KM_USER0 macro is only defined for HIGHMEM.

   Having to treat this special case everywhere makes the
   code needlessly complex. The parameter for zeroing is always
   KM_USER0 except in one single case that we open code.

Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.

Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.

Also extract the flushing of the caches to be outside of the kmap.

[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Call this the "inode_lock" now, since it covers both data and meta data.
This patch makes no functional changes.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

ocfs2_extend_trans() might call journal_restart() which will commit dirty
buffers and then restart the transaction. This means that any buffers which
still need changes should be passed to journal_access() again. Some paths
during extend weren't doing this right.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This BUG_ON() was unintentionally left in after the sparse file support was
written.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Fixes priority mistakes similar to '!x & y'
Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Create all new directories with OCFS2_INLINE_DATA_FL and the inline data
bytes formatted as an empty directory. Inode size field reflects the actual
amount of inline data available, which makes searching for dirent space
very similar to the regular directory search.

Inline-data directories are automatically pushed out to extents on any
insert request which is too large for the available space.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: NJoel Becker <joel.becker@oracle.com>

This fixes up write, truncate, mmap, and RESVSP/UNRESVP to understand inline
inode data.

For the most part, the changes to the core write code can be relied on to do
the heavy lifting. Any code calling ocfs2_write_begin (including shared
writeable mmap) can count on it doing the right thing with respect to
growing inline data to an extent tree.

Size reducing truncates, including UNRESVP can simply zero that portion of
the inode block being removed. Size increasing truncatesm, including RESVP
have to be a little bit smarter and grow the inode to an extent tree if
necessary.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: NJoel Becker <joel.becker@oracle.com>

We'll want to reuse most of this when pushing inline data back out to an
extent. Keeping this part as a seperate patch helps to keep the upcoming
changes for write support uncluttered.

The core portion of ocfs2_zero_cluster_pages() responsible for making sure a
page is mapped and properly dirtied is abstracted out into it's own
function, ocfs2_map_and_dirty_page(). Actual functionality doesn't change,
though zeroing becomes optional.

We also turn part of ocfs2_free_write_ctxt() into  a common function for
unlocking and freeing a page array. This operation is very common (and
uniform) for Ocfs2 cluster sizes greater than page size, so it makes sense
to keep the code in one place.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: NJoel Becker <joel.becker@oracle.com>

c_used_tail_recs in struct ocfs2_merge_ctxt is only ever set, so we can
remove it.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

delete_tail_recs in ocfs2_try_to_merge_extent() was only ever set, remove
it.
Signed-off-by: NTao Mao <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

ocfs2_insert_type->ins_free_records was only used in one place, and was set
incorrectly in most places. We can free up some memory and lose some code by
removing this.

* Small warning fixup contributed by Andrew Mortom <akpm@linux-foundation.org>
Signed-off-by: NTao Mao <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

We were setting i_blocks too early - before truncating any allocation.
Correct things to set i_blocks after the allocation change.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This patch removes some now dead code.

Spotted by the Coverity checker.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Provide an internal interface for the removal of arbitrary file regions.

ocfs2_remove_inode_range() takes a byte range within a file and will remove
existing extents within that range. Partial clusters will be zeroed so that
any read from within the region will return zeros.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The partial cluster zeroing code used during truncate usually assumes that
the rightmost byte in the range to be zeroed lies on a cluster boundary.
This makes sense for truncate, but punching holes might require zeroing on
non-aligned rightmost boundaries.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Add code to the btree paths to support the removal of arbitrary regions
within an existing extent. With proper higher level support this can be used
to "punch holes" in a file. Truncate (a special case of hole punching) could
also be converted to use these methods.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This can now be trivially supported with re-use of our existing extend code.

ocfs2_allocate_unwritten_extents() takes a start offset and a byte length
and iterates over the inode, adding extents (marked as unwritten) until len
is reached. Existing extents are skipped over.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Writes to a region marked as unwritten might result in a record split or
merge. We can support splits by making minor changes to the existing insert
code. Merges require left rotations which mostly re-use right rotation
support functions.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The top level calls and logic for growing a tree can easily be abstracted
out of ocfs2_insert_extent() into a seperate function - ocfs2_grow_tree().

This allows future code to easily grow btrees when needed.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Now that we have a method to deallocate blocks from them, each node should
allocate extent blocks from their local suballocator file.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Deallocation of suballocator blocks, most notably extent blocks, might
involve multiple suballocator inodes.

The locking for this can get extremely complicated, especially when the
suballocator inodes to delete from aren't known until deep within an
unrelated codepath.

Implement a simple scheme for recording the blocks to be unlinked so that
the actual deallocation can be done in a context which won't deadlock.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Use of the alloc sem during truncate was too narrow - we want to protect
the i_size change and page truncation against mmap now.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

None of these are actually harmful, but the noise makes looking for real
problems difficult.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The extent map code was ripped out earlier because of an inability to deal
with holes. This patch adds back a simpler caching scheme requiring far less
code.

Our old extent map caching was designed back when meta data block caching in
Ocfs2 didn't work very well, resulting in many disk reads. These days our
metadata caching is much better, resulting in no un-necessary disk reads. As
a result, extent caching doesn't have to be as fancy, nor does it have to
cache as many extents. Keeping the last 3 extents seen should be sufficient
to give us a small performance boost on some streaming workloads.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Return an optional extent flags field from our lookup functions and wire up
callers to treat unwritten regions as holes for the purpose of returning
zeros to the user.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Due to the size of our group bitmaps, we'll never have a leaf node extent
record with more than 16 bits worth of clusters. Split e_clusters up so that
leaf nodes can get a flags field where we can mark unwritten extents.
Interior nodes whose length references all the child nodes beneath it can't
split their e_clusters field, so we use a union to preserve sizing there.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Do this instead of filemap_fdatawrite() - this way we sync only the
range between i_size and the cluster boundary.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Since we don't zero on extend anymore, truncate needs to be fixed up to zero
the part of a file between i_size and and end of it's cluster. Otherwise a
subsequent extend could expose bad data.

This introduced a new helper, which can be used in ocfs2_write().
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

For ocfs2_truncate_file(), we eliminate the "simple" truncate case which no
longer exists since i_size is not tied to i_clusters. In
ocfs2_extend_file(), we skip the allocation / page zeroing code for file
systems which understand sparse files.

The core truncate code is changed to do a bottom up tree traversal. This
gets abstracted out into it's own function. To make things more readable,
most of the special case handling for in-inode extents from
ocfs2_do_truncate() is also removed.

Though write support for sparse files comes in a later patch, we at least
update ocfs2_prepare_inode_for_write() to skip allocation for sparse files.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The code in extent_map.c is not prepared to deal with a subtree being
rotated between lookups. This can happen when filling holes in sparse files.
Instead of a lengthy patch to update the code (which would likely lose the
benefit of caching subtree roots), we remove most of the algorithms and
implement a simple path based lookup. A less ambitious extent caching scheme
will be added in a later patch.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Introduce tree rotations into the b-tree code. This will allow ocfs2 to
support sparse files. Much of the added code is designed to be generic (in
the ocfs2 sense) so that it can later be re-used to implement large
extended attributes.

This patch only adds the rotation code and does minimal updates to callers
of the extent api.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

All kcalloc() calls of the form "kcalloc(1,...)" are converted to the
equivalent kzalloc() calls, and a few kcalloc() calls with the incorrect
ordering of the first two arguments are fixed.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is mostly a search and replace as ocfs2_journal_handle is now no more
than a container for a handle_t pointer.

ocfs2_commit_trans() becomes very straight forward, and we remove some out
of date comments / code.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

All callers either pass in NULL directly, or a local variable that is
already set to NULL.

The internals of ocfs2_start_trans() get a nice cleanup as a result.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This sets us up to remove handle->journal.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>