We re-use the RESVSP/UNRESVSP ioctls from xfs which allow the user to
allocate and deallocate regions to a file without zeroing data or changing
i_size.

Though renamed, the structure passed in from user is identical to struct
xfs_flock64. The three fields that are actually used right now are l_whence,
l_start and l_len.

This should get ocfs2 immediate compatibility with userspace software using
the pre-existing xfs ioctls.
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>

Update the write code to detect when the user is asking to write to an
unwritten extent. Like writing to a hole, we must zero the region between
the write and the cluster boundaries. Most of the existing cluster zeroing
logic can be re-used with some additional checks for the unwritten flag on
extent records.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This patch makes the following needlessly global functions static:
- aops.c: ocfs2_write_data_page()
- dlmglue.c: ocfs2_dump_meta_lvb_info()
- file.c: ocfs2_set_inode_size()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Unfortunately, ocfs2 can no longer make use of generic_file_aio_write_nlock()
because allocating writes will require zeroing of pages adjacent to the I/O
for cluster sizes greater than page size.

Implement a custom file write here, which can order page locks for zeroing.
This also has the advantage that cluster locks can easily be ordered outside
of the page locks.
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>

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement .permission() in ocfs2_file_iops, ocfs2_special_file_iops and
ocfs2_dir_iops.

This helps us avoid some multi-node races with mode change and vfs
operations.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This patch adds the core routines for updating atime in ocfs2.
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

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>

This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The OCFS2 file system module.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>