This removes the extra filldir callback which gfs2 was using to
enclose an attempt at readahead for inodes during readdir. The
code was too complicated and also hurts performance badly in the
case that the getdents64/readdir call isn't being followed by
stat() and it wasn't even getting it right all the time when it
was.

As a result, on my test box an "ls" of a directory containing 250000
files fell from about 7mins (freshly mounted, so nothing cached) to
between about 15 to 25 seconds. When the directory content was cached,
the time taken fell from about 3mins to about 4 or 5 seconds.

Interestingly in the cached case, running "ls -l" once reduced the time
taken for subsequent runs of "ls" to about 6 secs even without this
patch. Now it turns out that there was a special case of glocks being
used for prefetching the metadata, but because of the timeouts for these
locks (set to 10 secs) the metadata was being timed out before it was
being used and this the prefetch code was constantly trying to prefetch
the same data over and over.

Calling "ls -l" meant that the inodes were brought into memory and once
the inodes are cached, the glocks are not disposed of until the inodes
are pushed out of the cache, thus extending the lifetime of the glocks,
and thus bringing down the time for subsequent runs of "ls"
considerably.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The comment explains why we use the bio functions to read
the super block.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Srinivasa Ds <srinivasa@in.ibm.com>

  While mounting the gfs2 filesystem,our test team had a problem and we
got this error message.
=======================================================

GFS2: fsid=: Trying to join cluster "lock_nolock", "dasde1"
GFS2: fsid=dasde1.0: Joined cluster. Now mounting FS...
GFS2: not a GFS2 filesystem
GFS2: fsid=dasde1.0: can't read superblock: -22

==========================================================================
On debugging further we found that problem is while reading the super
block(gfs2_read_super) and comparing the magic number in it.
When I  replace the submit_bio() call(present in gfs2_read_super) with
the sb_getblk() and ll_rw_block(), mount operation succeded.
On further analysis we found that before calling submit_bio(),
bio->bi_sector was set to "sector" variable. This "sector" variable has
the same value of bh->b_blocknr(block number). Hence there is a need to
multiply this valuwith (blocksize >> 9)(9 because,sector size
2^9,samething happens in ll_rw_block also, before calling submit_bio()).
So I have developed the patch which solves this problem. Please let me
know your comments.
================================================================
Signed-off-by: NSrinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The go_sync callback took two flags, but one of them was set on every
call, so this patch removes once of the flags and makes the previously
conditional operations (on this flag), unconditional.

The go_inval callback took three flags, each of which was set on every
call to it. This patch removes the flags and makes the operations
unconditional, which makes the logic rather more obvious.

Two now unused flags are also removed from incore.h.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

For some reason we had two different sets of code for reading in the
superblock. This removes one of them in favour of the other. Also we
don't need the temporary buffer for the sb since we already have one
in the gfs2 sb itself.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As per Andrew Morton's request, removed trailing whitespace.

Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

lm_interface.h has a few out of the tree clients such as GFS1
and userland tools.

Right now, these clients keeps a copy of the file in their build tree
that can go out of sync.

Move lm_interface.h to include/linux, export it to userland and
clean up fs/gfs2 to use the new location.
Signed-off-by: NFabio M. Di Nitto <fabbione@ubuntu.com>
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>

This makes everything consistent.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

As per Jan Engelhardt's third set of comments, this make various
code style changes and moves the structures from format.h into
super.c, which was the only place that format.h was actually used.

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 gets the argument to submit_bio() correct.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This means that we don't need to create a special inode just to contain
a struct address_space in order to read a single disk block. Instead
we read the disk block directly. Its slightly faster, and uses slightly
less memory, but the real reason for doing this is that it removes a
special case from the glock code.
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 patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 unused functions
- remove the following global function that was both unused and
  unimplemented:
  - super.c: gfs2_do_upgrade()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

There is no point in keeping this flag since recursion is not
now allowed for any glock.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This reduces the size of the directory code by about 3k and gets
readdir() to use the functions which were introduced in the previous
directory code update.

Two memory allocations are merged into one. Eliminates zeroing of some
buffers which were never used before they were initialised by
other data.

There is still scope for further improvement in the directory code.

On the logging side, a hand created mutex has been replaced by a
standard Linux mutex in the log allocation code.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Due to a typo, the dir leaf split operation was (for the first
split in a directory) writing the new hash vaules at the
wrong offset. This is now fixed.

Also some other tidy ups are included:

 - We use GFS2's hash function for dentries (see ops_dentry.c) so that
   we don't have to keep recalculating the hash values.
 - A lot of common code is eliminated between the various directory
   lookup routines.
 - Better error checking on directory lookup (previously different
   routines checked for different errors)
 - The leaf split operation has a couple of redundant operations
   removed from it, so it should be faster.

There is still further scope for further clean ups in the directory
code, and readdir in particular could do with slimming down a bit.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

We no longer lookup ".gfs2_admin" in the root directory in order to
find it, but instead use the inode number given in the superblock.
Both the root directory and the admin directory are now looked up using
the same routine, so the redundant code is removed.

Also, there is no longer a reference to the root inode in the
GFS2 super block. When required this can be retreived via
sb->s_root->d_inode instead.

Assuming that we introduce a metadata filesystem type for GFS, then
this is a first step towards that goal.
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>

All printk calls now have KERN_ set where required and a couple of
kmalloc(), memset(.., 0, ...) calls changed to kzalloc().

This is in response to comments from:
Pekka Enberg <penberg@cs.helsinki.fi> and
Eric Sesterhenn <snakebyte@gmx.de>
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>

Umount is now working correctly again. The bug was due to
not getting an extra ref count when mounting the fs. We
should have bumped it by two (once for the internal pointer
to the root inode from the super block and once for the
inode hanging off the dcache entry for root).

Also this patch tidys up the code dealing with looking up
and creating inodes. We now pass Linux inodes (with gfs2_inodes
attached) rather than the other way around and this reduces code
duplication in various places.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Add the new external read function. Its temporarily in jdata.c
even though the protoype is in ops_file.h - this will change
shortly. The current implementation will change to a page cache
one when that happens.

In order to effect the above changes, the various internal inodes
now have Linux inodes attached to them. We keep the references to
the Linux inodes, rather than the gfs2_inodes in the super block.

In order to get everything to work correctly I've had to reorder
the init sequence on mount (which I should probably have done
earlier when .gfs2_admin was made visible).
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>