As per the remainder of Jan Engelhardt's fourth email comments,
remove an cast thats not required. Also tidy up the "limit" code
in stuck_releasepage().

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

A spelling mistake (one of mine).

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This makes all fixed size types have consistent names.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As per comments from Jan Engelhardt <jengelh@linux01.gwdg.de> this
updates the copyright message to say "version" in full rather than
"v.2". Also incore.h has been updated to remove forward structure
declarations which are not required.

The gfs2_quota_lvb structure has now had endianess annotations added
to it. Also quota.c has been updated so that we now store the
lvb data locally in endian independant format to avoid needing
a structure in host endianess too. As a result the endianess
conversions are done as required at various points and thus the
conversion routines in lvb.[ch] are no longer required. I've
moved the one remaining constant in lvb.h thats used into lm.h
and removed the unused lvb.[ch].

I have not changed the HIF_ constants. That is left to a later patch
which I hope will unify the gh_flags and gh_iflags fields of the
struct gfs2_holder.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch fixes three main bugs. Firstly the direct i/o get_block
was returning the wrong return code in certain cases. Secondly, the
GFS2's releasepage function was not dealing with cases when clean,
ordered buffers were found still queued on a transaction (which can
happen depending on the ordering of journal flushes). Thirdly, the
journaling code itself needed altering to take account of the
after effects of removing the clean ordered buffers from the transactions
before a journal flush.

The releasepage bug did also show up under "normal" buffered i/o
as well, so its not just a fix for direct i/o. In fact its not
normally used in the direct i/o path at all, except when flushing
existing buffers after performing a direct i/o write, but that was
the code path that led us to spot this.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This should clarify the logic in gfs2_releasepage() relating to
error handling as well as making the response to errors a bit
more graceful.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This fixes a memory leak of struct gfs2_bufdata and also some
problems in the ordered write handling code. It needs a bit
more testing, but I believe that the reference counting of
ordered write buffers should now be correct.

This is aimed at fixing Red Hat bugzilla: #201028 and #201082
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

In some cases we can enter write page without there being buffers
attached to the page. In this case the function to add gfs2_bufdata
to the buffers fails sliently causing further failures down the
stack.

This fix ensures that we always add buffers in writepage if they
didn't already exist (mmap is one way to trigger this).
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Mmapped files were able to trigger a lock ordering bug. Private
maps do not need to take the glock so early on. Shared maps do
unfortunately, however we can get around that by adding a flag
into the flags for the struct gfs2_file. This only works because
we are taking an exclusive lock at this point, so we know that
nobody else can be racing with us.

Fixes Red Hat bugzilla: #201196
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The remaining routines in page.c were all only used in one other
file, so they are now moved into the files where they are referenced
and made static. Thus page.[ch] are no longer required.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Tidy up gfs2_unstuffer_page by:

 a) Moving it into bmap.c
 b) Making it static
 c) Calling it directly from gfs2_unstuff_dinode
 d) Updating all callers of gfs2_unstuff_dinode due to one less
    required argument.

It doesn't change the behaviour at all.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As per comments received, alter the GFS2 direct I/O path so that
it uses the standard read functions "out of the box". Needs a
small change to one of the VFS functions. This reduces the size
of the code quite a lot and also removes the need for one new export.

Some more work remains to be done, but this is the bones of the
thing.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This adds a generation number for the eventual use of NFS to the
ondisk inode. Its backward compatible with the current code since
it doesn't really matter what the generation number is to start with,
and indeed since its set to zero, due to it being taken from padding
in both the inode and rgrp header, it should be fine.

The eventual plan is to use this rather than no_formal_ino in the
NFS filehandles. At that point no_formal_ino will be unused.

At the same time we also add a releasepages call back to the
"normal" address space for gfs2 inodes. Also I've removed a
one-linrer function thats not required any more.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This fixes a bug where we were releasing a page incorrectly
sometimes when reading a stuffed file. This fixes the bug
that Kevin reported when using Xen.

Cc: Kevin Anderson <kanderso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

We need to hold i_mutex when doing direct i/o reads.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As per Christoph's patch:
http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=f5e54d6e53a20cef45af7499e86164f0e0d16bb2

We mark struct address_space_operations const in GFS2.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch fixes the way we have been dealing with unlinked,
but still open files. It removes all limits (other than memory
for inodes, as per every other filesystem) on numbers of these
which we can support on GFS2. It also means that (like other
fs) its the responsibility of the last process to close the file
to deallocate the storage, rather than the person who did the
unlinking. Note that with GFS2, those two events might take place
on different nodes.

Also there are a number of other changes:

 o We use the Linux inode subsystem as it was intended to be
used, wrt allocating GFS2 inodes
 o The Linux inode cache is now the point which we use for
local enforcement of only holding one copy of the inode in
core at once (previous to this we used the glock layer).
 o We no longer use the unlinked "special" file. We just ignore it
completely. This makes unlinking more efficient.
 o We now use the 4th block allocation state. The previously unused
state is used to track unlinked but still open inodes.
 o gfs2_inoded is no longer needed
 o Several fields are now no longer needed (and removed) from the in
core struct gfs2_inode
 o Several fields are no longer needed (and removed) from the in core
superblock

There are a number of future possible optimisations and clean ups
which have been made possible by this patch.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

We no longer use semaphores, everything has been converted to
mutex or rwsem, so we don't need to include this header any more.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This adds readpages support (and also corrects a small bug in
the readpage error path at the same time). Hopefully this will
improve performance by allowing GFS to submit larger lumps of
I/O at a time.

In order to simplify the setting of BH_Boundary, it currently gets
set when we hit the end of a indirect pointer block. There is
always a boundary at this point with the current allocation code.
It doesn't get all the boundaries right though, so there is still
room for improvement in this.

See comments in fs/gfs2/ops_address.c for further information about
readpages with GFS2.

Signed-off-by: Steven Whitehouse

As pointed out by Wendy Cheng, the logic in GFS2's writepage() function
wasn't quite right with respect to invalidating pages when a file has been
truncated. This patch fixes that.

CC: Wendy Cheng <wcheng@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

When allocating memory to sort directory entries, use vmalloc()
rather than kmalloc() since for larger directories, the required
size can easily be graeter than the 128k maximum of kmalloc().

Also adding the first steps towards getting the AOP_TRUNCATED_PAGE
return code get in the glock code by flagging all places where we
request a glock and we are holding a page lock.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Some interfaces have changed. In particular one of the posix
locking functions has changed prototype, along with the
address space operation invalidatepage and the block getting
callback to the direct IO function.

In addition add the splice file operations. These will need to
be updated to support AOP_TRUNCATED_PAGE before they will be
of much use to us.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As suggested by Pekka Enberg <penberg@cs.helsinki.fi>.

The DIV_RU macro is renamed DIV_ROUND_UP and and moved to kernel.h
The other macros are gone from gfs2.h as (although not requested
by Pekka Enberg) are a number of included header file which are now
included individually. The inode number comparison function is
now an inline function.

The DT2IF and IF2DT may be addressed in a future patch.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Requested by:
Prarit Bhargava <prarit@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As well as a number of minor bug fixes, this patch changes GFS
to use mutices rather than semaphores. This results in better
information in case there are any locking problems.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

There was a bug in the unstuffing logic which caused a crash
under certain circumstances. This is now fixed.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Two internal files which are read through the gfs2_internal_read()
routine were already locked when the routine was called and this
do not need locking at the redapages level.

This patch introduces a struct file which is used as a sentinal
so that readpage will only perform locking in the case that the
struct file passed to it is _not_ equal to this sentinal.

Since the comments in the generic kernel code indicate that the
struct file will never be used for anything other than passing
straight through to readpage(), this should be ok.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch adds back O_DIRECT support with various caveats
attached:

 1. Journaled data can be read via O_DIRECT since its now the
    same on disk format as normal data files.
 2. Journaled data writes with O_DIRECT will be failed sliently
    back to normal writes (should we really do this I wonder or
    should we return an error instead?)
 3. Stuffed files will be failed back to normal buffered I/O
 4. All the usual corner cases (write beyond current end of file,
    write to an unallocated block) will also revert to normal buffered I/O.

The I/O path is slightly odd as reads arrive at the page cache layer
with the lock for the file already held, but writes arrive unlocked.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This is a very large patch, with a few still to be resolved issues
so you might want to check out the previous head of the tree since
this is known to be unstable. Fixes for the various bugs will be
forthcoming shortly.

This patch removes the special data format which has been used
up till now for journaled data files. Directories still retain the
old format so that they will remain on disk compatible with earlier
releases. As a result you can now do the following with journaled
data files:

 1) mmap them
 2) export them over NFS
 3) convert to/from normal files whenever you want to (the zero length
    restriction is gone)

In addition the level at which GFS' locking is done has changed for all
files (since they all now use the page cache) such that the locking is
done at the page cache level rather than the level of the fs operations.
This should mean that things like loopback mounts and other things which
touch the page cache directly should now work.

Current known issues:

 1. There is a lock mode inversion problem related to the resource
    group hold function which needs to be resolved.
 2. Any significant amount of I/O causes an oops with an offset of hex 320
    (NULL pointer dereference) which appears to be related to a journaled data
    buffer appearing on a list where it shouldn't be.
 3. Direct I/O writes are disabled for the time being (will reappear later)
 4. There is probably a deadlock between the page lock and GFS' locks under
    certain combinations of mmap and fs operation I/O.
 5. Issue relating to ref counting on internally used inodes causes a hang
    on umount (discovered before this patch, and not fixed by it)
 6. One part of the directory metadata is different from GFS1 and will need
    to be resolved before next release.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Update the function in GFS2 which deals with truncation of
partial blocks. Some of the code is "borrowed" from ext3
since it appears to give a good model of how to do this
operation. The function is renamed gfs2_block_truncate_page
accordingly.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This renames get_block to gfs2_get_block and makes it accessible
from outside ops_address.c.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Removing the gfs2_databuf structure and using gfs2_bufdata instead
is a step towards allowing journaling of data without requiring the
metadata header on each journaled block. The idea is to merge the
code paths for ordered data with that of journaled data, with the
log operations in lops.c tacking account of the different types of
buffers as they are presented to it. Largely the code path for
metadata will be similar too, but obviously through a different set
of log operations.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This adds an extra argument to gfs2_trans_add_bh() to indicate whether the
bh being added to the transaction is metadata or data. Its currently unused
since all existing callers set it to 1 (metadata) but following patches will
make use of it.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch contains all the core files for GFS2.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>