Commit Graph

106 Commits

Author SHA1 Message Date
Steven Whitehouse
b99b98dc26 GFS2: Move readahead of metadata during deallocation into its own function
Move the recently added readahead of the indirect pointer
tree during deallocation into its own function in order
that we can use it elsewhere in the future. Also this
fixes the resetting of the "first" variable in the
original patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:54 +01:00
Benjamin Marzinski
64dd153c83 GFS2: rewrite fallocate code to write blocks directly
GFS2's fallocate code currently goes through the page cache. Since it's only
writing to the end of the file or to holes in it, it doesn't need to, and it
was causing issues on low memory environments. This patch pulls in some of
Steve's block allocation work, and uses it to simply allocate the blocks for
the file, and zero them out at allocation time.  It provides a slight
performance increase, and it dramatically simplifies the code.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:49 +01:00
Bob Peterson
bd5437a7d4 GFS2: speed up delete/unlink performance for large files
This patch improves the performance of delete/unlink
operations in a GFS2 file system where the files are large
by adding a layer of metadata read-ahead for indirect blocks.
Mileage will vary, but on my system, deleting an 8.6G file
dropped from 22 seconds to about 4.5 seconds.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:47 +01:00
Steven Whitehouse
70b0c3656f GFS2: Use cached rgrp in gfs2_rlist_add()
Each block which is deallocated, requires a call to gfs2_rlist_add()
and each of those calls was calling gfs2_blk2rgrpd() in order to
figure out which rgrp the block belonged in. This can be speeded up
by making use of the rgrp cached in the inode. We also reset this
cached rgrp in case the block has changed rgrp. This should provide
a big reduction in gfs2_blk2rgrpd() calls during deallocation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:39 +01:00
Steven Whitehouse
d56fa8a1c1 GFS2: Call do_strip() directly from recursive_scan()
The recursive_scan() function only ever takes a single "bc"
argument, so we might as well just call do_strip() directly
from resource_scan() rather than pass it in as an argument.

Also the "data" argument is always a struct strip_mine, so
we can pass that in, rather than using a void pointer.

This also moves do_strip() ahead of recursive_scan() so that
we don't need to add a prototype.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:38 +01:00
Steven Whitehouse
8339ee543e GFS2: Make resource groups "append only" during life of fs
Since we have ruled out supporting online filesystem shrink,
it is possible to make the resource group list append only
during the life of a super block. This gives several benefits:

Firstly, we only need to read new rindex elements as they are added
rather than needing to reread the whole rindex file each time one
element is added.

Secondly, the rindex glock can be held for much shorter periods of
time, and is completely removed from the fast path for allocations.
The lock is taken in shared mode only when updating the resource
groups when the first allocation occurs, and after a grow has
taken place.

Thirdly, this results in a reduction in code size, and everything
gets a lot simpler to understand in this area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:33 +01:00
Linus Torvalds
bbd9d6f7fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Christoph Hellwig
562c72aa57 fs: move inode_dio_wait calls into ->setattr
Let filesystems handle waiting for direct I/O requests themselves instead
of doing it beforehand.  This means filesystem-specific locks to prevent
new dio referenes from appearing can be held.  This is important to allow
generalizing i_dio_count to non-DIO_LOCKING filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:47 -04:00
Eric Sandeen
46fcb2ed29 GFS2: combine duplicated block freeing routines
__gfs2_free_data and __gfs2_free_meta are almost identical, and
can be trivially combined.

[This is as per Eric's original patch minus gfs2_free_data() which had
 no callers left and plus the conversion of the bmap.c calls to these
 functions. All in all, a nice clean up]

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-07-15 09:32:52 +01:00
Steven Whitehouse
6d3117b412 GFS2: Wipe directory hash table metadata when deallocating a directory
The deallocation code for directories in GFS2 is largely divided into
two parts. The first part deallocates any directory leaf blocks and
marks the directory as being a regular file when that is complete. The
second stage was identical to deallocating regular files.

Regular files have their data blocks in a different
address space to directories, and thus what would have been normal data
blocks in a regular file (the hash table in a GFS2 directory) were
deallocated correctly. However, a reference to these blocks was left in the
journal (assuming of course that some previous activity had resulted in
those blocks being in the journal or ail list).

This patch uses the i_depth as a test of whether the inode is an
exhash directory (we cannot test the inode type as that has already
been changed to a regular file at this stage in deallocation)

The original issue was reported by Chris Hertel as an issue he encountered
running bonnie++

Reported-by: Christopher R. Hertel <crh@samba.org>
Cc: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-21 14:05:58 +01:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Bob Peterson
4c16c36ad6 GFS2: deallocation performance patch
This patch is a performance improvement to GFS2's dealloc code.
Rather than update the quota file and statfs file for every
single block that's stripped off in unlink function do_strip,
this patch keeps track and updates them once for every layer
that's stripped.  This is done entirely inside the existing
transaction, so there should be no risk of corruption.
The other functions that deallocate blocks will be unaffected
because they are using wrapper functions that do the same
thing that they do today.

I tested this code on my roth cluster by creating 200
files in a directory, each of which is 100MB, then on
four nodes, I simultaneously deleted the files, thus competing
for GFS2 resources (but different files).  The commands
I used were:

[root@roth-01]# time for i in `seq 1 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done
[root@roth-02]# time for i in `seq 2 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done
[root@roth-03]# time for i in `seq 3 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done
[root@roth-05]# time for i in `seq 4 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done

The performance increase was significant:

             roth-01     roth-02     roth-03     roth-05
             ---------   ---------   ---------   ---------
old: real    0m34.027    0m25.021s   0m23.906s   0m35.646s
new: real    0m22.379s   0m24.362s   0m24.133s   0m18.562s

Total time spent deleting:
old: 118.6s
new:  89.4

For this particular case, this showed a 25% performance increase for
GFS2 unlinks.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-02-24 12:13:48 +00:00
Steven Whitehouse
e06dfc4928 GFS2: Fix uninitialised error value in previous patch
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30 15:46:02 +00:00
Benjamin Marzinski
086d8334cf GFS2: fix recursive locking during rindex truncates
When you truncate the rindex file, you need to avoid calling gfs2_rindex_hold,
since you already hold it.  However, if you haven't already read in the
resource groups, you need to do that.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30 15:41:54 +00:00
Benjamin Marzinski
bf97b6734e GFS2: reserve more blocks for transactions
Some of the functions in GFS2 were not reserving space in the transaction for
the resource group header and the resource groups bitblocks that get added
when you do allocation. GFS2 now makes sure to reserve space for the
resource group header and either all the bitblocks in the resource group, or
one for each block that it may allocate, whichever is smaller using the new
gfs2_rg_blocks() inline function.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-28 09:44:24 +01:00
Steven Whitehouse
a2e0f79939 GFS2: Remove i_disksize
With the update of the truncate code, ip->i_disksize and
inode->i_size are merely copies of each other. This means
we can remove ip->i_disksize and use inode->i_size exclusively
reducing the size of a GFS2 inode by 8 bytes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-20 11:18:29 +01:00
Steven Whitehouse
ff8f33c8b3 GFS2: New truncate sequence
This updates GFS2's truncate code to use the new truncate
sequence correctly. This is a stepping stone to being
able to remove ip->i_disksize in favour of using i_size
everywhere now that the two sizes are always identical.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
2010-09-20 11:18:16 +01:00
Abhijith Das
c639d5d8f6 GFS2: Fix typo in stuffed file data copy handling
trunc_start() in bmap.c incorrectly uses sizeof(struct gfs2_inode) instead of
sizeof(struct gfs2_dinode).

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-07-30 16:34:06 +01:00
Bob Peterson
461cb419f0 GFS2: Simplify gfs2_write_alloc_required
Function gfs2_write_alloc_required always returned zero as its
return code.  Therefore, it doesn't need to return a return code
at all.  Given that, we can use the return value to return whether
or not the dinode needs block allocations rather than passing
that value in, which in turn simplifies a bunch of error checking.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-07-29 09:36:56 +01:00
Bob Peterson
a8bf2bc212 GFS2: O_TRUNC not working on stuffed files across cluster
This patch replaces a statement that got dropped out by accident.
Without the patch, truncates on stuffed (very small) files cause
those files to have an unpredictable size.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-07-15 09:05:17 +01:00
Linus Torvalds
677abe49ad Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw:
  GFS2: Fix typo
  GFS2: stuck in inode wait, no glocks stuck
  GFS2: Eliminate useless err variable
  GFS2: Fix writing to non-page aligned gfs2_quota structures
  GFS2: Add some useful messages
  GFS2: fix quota state reporting
  GFS2: Various gfs2_logd improvements
  GFS2: glock livelock
  GFS2: Clean up stuffed file copying
  GFS2: docs update
  GFS2: Remove space from slab cache name
2010-05-21 07:29:15 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Steven Whitehouse
602c89d2e3 GFS2: Clean up stuffed file copying
If the inode size was corrupt for stuffed files, it was possible
for the copying of data to overrun the block and/or page. This patch
checks for that condition so that this is no longer possible.

This is also preparation for the new truncate sequence patch which
requires the ability to have stuffed files with larger sizes than
(disk block size - sizeof(on disk inode)) with the restriction that
only the initial part of the file may be non-zero.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-03-29 14:29:17 +01:00
Steven Whitehouse
07ccb7bf2c GFS2: Fix bmap allocation corner-case bug
This patch solves a corner case during allocation which occurs if both
metadata (indirect) and data blocks are required but there is an
obstacle in the filesystem (e.g. a resource group header or another
allocated block) such that when the allocation is requested only
enough blocks for the metadata are returned.

By changing the exit condition of this loop, we ensure that a
minimum of one data block will always be returned.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-02-12 10:16:14 +00:00
Steven Whitehouse
63997775b7 GFS2: Add tracepoints
This patch adds the ability to trace various aspects of the GFS2
filesystem. The trace points are divided into three groups,
glocks, logging and bmap. These points have been chosen because
they allow inspection of the major internal functions of GFS2
and they are also generic enough that they are unlikely to need
any major changes as the filesystem evolves.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-06-12 08:49:20 +01:00
Steven Whitehouse
40bc9a27e0 GFS2: Fix cache coherency between truncate and O_DIRECT read
If a page was partially zeroed as the result of a truncate, then it was
not being correctly marked dirty. This resulted in the deleted data
reappearing if the file was read back via direct I/O.

Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-06-10 09:09:40 +01:00
Steven Whitehouse
b1e71b0622 GFS2: Clean up some file names
This patch renames the ops_*.c files which have no counterpart
without the ops_ prefix in order to shorten the name and make
it more readable. In addition, ops_address.h (which was very
small) is moved into inode.h and inode.h is cleaned up by
adding extern where required.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-22 10:01:55 +01:00
Steven Whitehouse
0901097834 GFS2: Improve resource group error handling
This patch improves the error handling in the case where we
discover that the summary information in the resource group
doesn't match the bitmap information while in the process of
allocating blocks. Originally this resulted in a kernel bug,
but this patch changes that so that we return -EIO and print
some messages explaining what went wrong, and how to fix it.

We also remember locally not to try and allocate from the
same rgrp again, so that a subsequent allocation in a
different rgrp should succeed.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-20 10:48:47 +01:00
Steven Whitehouse
f057f6cdf6 GFS2: Merge lock_dlm module into GFS2
This is the big patch that I've been working on for some time
now. There are many reasons for wanting to make this change
such as:
 o Reducing overhead by eliminating duplicated fields between structures
 o Simplifcation of the code (reduces the code size by a fair bit)
 o The locking interface is now the DLM interface itself as proposed
   some time ago.
 o Fewer lookups of glocks when processing replies from the DLM
 o Fewer memory allocations/deallocations for each glock
 o Scope to do further optimisations in the future (but this patch is
   more than big enough for now!)

Please note that (a) this patch relates to the lock_dlm module and
not the DLM itself, that is still a separate module; and (b) that
we retain the ability to build GFS2 as a standalone single node
filesystem with out requiring the DLM.

This patch needs a lot of testing, hence my keeping it I restarted
my -git tree after the last merge window. That way, this has the maximum
exposure before its merged. This is (modulo a few minor bug fixes) the
same patch that I've been posting on and off the the last three months
and its passed a number of different tests so far.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24 11:21:14 +00:00
Steven Whitehouse
7ed122e42c GFS2: Streamline alloc calculations for writes
This patch removes some unused code, and make the calculation
of the number of blocks required conditional in order to reduce
the number of times this (potentially expensive) calculation
is done.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:39:17 +00:00
Steven Whitehouse
383f01fbf4 GFS2: Banish struct gfs2_dinode_host
The final field in gfs2_dinode_host was the i_flags field. Thats
renamed to i_diskflags in order to avoid confusion with the existing
inode flags, and moved into the inode proper at a suitable location
to avoid creating a "hole".

At that point struct gfs2_dinode_host is no longer needed and as
promised (quite some time ago!) it can now be removed completely.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:38:59 +00:00
Steven Whitehouse
c9e9888677 GFS2: Move i_size from gfs2_dinode_host and rename it to i_disksize
This patch moved the i_size field from the gfs2_dinode_host and
following the ext3 convention renames it i_disksize.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:38:58 +00:00
Benjamin Marzinski
5af4e7a0be [GFS2] fix gfs2 block allocation (cleaned up)
This patch fixes bz 450641.

This patch changes the computation for zero_metapath_length(), which it
renames to metapath_branch_start(). When you are extending the metadata
tree, The indirect blocks that point to the new data block must either
diverge from the existing tree either at the inode, or at the first
indirect block. They can diverge at the first indirect block because the
inode has room for 483 pointers while the indirect blocks have room for
509 pointers, so when the tree is grown, there is some free space in the
first indirect block. What metapath_branch_start() now computes is the
height where the first indirect block for the new data block is located.
It can either be 1 (if the indirect block diverges from the inode) or 2
(if it diverges from the first indirect block).

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-06-24 19:02:28 +01:00
Steven Whitehouse
d82661d969 [GFS2] Streamline quota lock/check for no-quota case
This patch streamlines the quota checking in the "no quota" case by
making the check inline in the calling function, thus reducing the
number of function calls. Eventually we might be able to remove the
checks from the gfs2_quota_lock() and gfs2_quota_check() functions, but
currently we can't as there are a very few places in the code which need
to call these functions directly still.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
2008-03-31 10:41:36 +01:00
Cyrill Gorcunov
182fe5abd8 [GFS2] possible null pointer dereference fixup
gfs2_alloc_get may fail so we have to check it to prevent
NULL pointer dereference.

Signed-off-by: Cyrill Gorcunov <gorcunov@gamil.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:41:28 +01:00
Steven Whitehouse
9b8c81d1de [GFS2] Allow bmap to allocate extents
We've supported mapping of extents when no block allocation is required
for some time. This patch extends that to mapping of extents when an
allocation has been requested. In that case we try to allocate as many
blocks as are requested, but we might return fewer in case there is
something preventing us from returning the complete amount (e.g. an
already allocated block is in the way).

Currently the only code path which can actually request multiple data
blocks in a single bmap call is the page_mkwrite path and even then it
only happens if there are multiple blocks per page. What this patch does
do however, is merge the allocation requests for metadata (growing the
metadata tree in either height or depth) with the allocation of the data
blocks in the case that both are needed. This results in lower overheads
even in the single block allocation case.

The one thing which we can't handle here at the moment is unstuffing. I
would like to be able to do that, but the problem which arises is that
in order to unstuff one has to get a locked page from the page cache
which results in locking problems in the (usual) case that the caller is
holding the page lock on the page it wishes to map. So that case will
have to be addressed in future patches.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:41:14 +01:00
Steven Whitehouse
e23159d2a7 [GFS2] Get inode buffer only once per block map call
In the case that we needed to grow the height of the metadata tree
we were looking up the inode buffer and then brelse()ing it despite
the fact that it is needed later in the block map process.

This patch ensures that we look up the inode's buffer once and only
once during the block map process.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:58 +01:00
Steven Whitehouse
77658aad22 [GFS2] Eliminate (almost) duplicate field from gfs2_inode
The blocks counter is almost a duplicate of the i_blocks
field in the VFS inode. The only difference is that i_blocks
can be only 32bits long for 32bit arch without large single file
support. Since GFS2 doesn't handle the non-large single file
case (for 32 bit anyway) this adds a new config dependency on
64BIT || LSF. This has always been the case, however we've never
explicitly said so before.

Even if we do add support for the non-LSF case, we will still
not require this field to be duplicated since we will not be
able to access oversized files anyway.

So the net result of all this is that we shave 8 bytes from a gfs2_inode
and get our config deps correct.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:55 +01:00
Steven Whitehouse
30cbf189cd [GFS2] Add a function to interate over an extent
This adds a function (currently the only use is during mapping
of already allocated blocks, but watch this space) which iterates
over a number of pointers in a block and returns the extent length.

If the initial pointer is 0 (i.e. unallocated) it will return the
number of unallocated blocks in the extent. If the initial pointer
is allocated, then it returns the number of contiguously allocated
blocks in the extent.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:53 +01:00
Steven Whitehouse
c85a665f06 [GFS2] The case of the missing asterisk
A dereference was forgotten. This adds it back correctly.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:50 +01:00
Steven Whitehouse
b45e41d7d5 [GFS2] Add extent allocation to block allocator
Rather than having to allocate a single block at a time, this patch
allows the block allocator to allocate an extent. Since there is
no difference (so far as the block allocator is concerned) between
data blocks and indirect blocks, it is posible to allocate a single
extent and for the caller to unrevoke just the blocks required
for indirect blocks.

Currently the only bit of GFS2 to make use of this feature is the
build height function. The intention is that gfs2_block_map will
be changed to make use of this feature in future patches.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:47 +01:00
Steven Whitehouse
1639431a3f [GFS2] Merge gfs2_alloc_meta and gfs2_alloc_data
Thanks to the preceeding patches, the only difference between
these two functions is their name. We can thus merge them
and call the new function gfs2_alloc_block to reflect the
fact that it can allocate either kind of block.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:45 +01:00
Steven Whitehouse
5731be53e3 [GFS2] Update gfs2_trans_add_unrevoke to accept extents
By adding an extra argument to gfs2_trans_add_unrevoke we can now
specify an extent length of blocks to unrevoke. This means that
we only need to make one pass through the list for each extent
rather than each block. Currently the only extent length which
is used is 1, but that will change in the future.

Also gfs2_trans_add_unrevoke is removed from gfs2_alloc_meta
since its the only difference between this and gfs2_alloc_data
which is left. This will allow a future patch to merge these
two functions into one (i.e. one call to allocate both data
and metadata in a single extent in the future).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:42 +01:00
Steven Whitehouse
ce276b06e8 [GFS2] Reduce inode size by merging fields
There were three fields being used to keep track of the location
of the most recently allocated block for each inode. These have
been merged into a single field in order to better keep the
data and metadata for an inode close on disk, and also to reduce
the space required for storage.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:37 +01:00
Steven Whitehouse
dbac6710a6 [GFS2] Introduce array of buffers to struct metapath
The reason for doing this is to allow all the block mapping code
to share the same array. As a result we can remove two arguments
from lookup_metapath since they are now returned via the array.

We also add a function to drop all refs to buffer heads when we
are done with the metapath. The build_height function shares the
struct metapath, but currently still frees its own buffers, and
this will change in a future patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:18 +01:00
Steven Whitehouse
11707ea05e [GFS2] Move part of gfs2_block_map into a separate function
This is required to enable future changes to the block
mapping code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:15 +01:00
Bob Peterson
7eabb77e65 [GFS2] Misc fixups
This patch contains two small fixups that didn't fit elsewhere.
They are: (1) get rid of temp variable in find_metapath.
(2) Remove vestigial "ret" variable from gfs2_writepage_common.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:39:57 +01:00
Bob Peterson
fe6c991c52 [GFS2] Get rid of unneeded parameter in gfs2_rlist_alloc
This patch removed the unnecessary parameter from function
gfs2_rlist_alloc.  The parameter was always passed in as 0.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:39:49 +01:00
Steven Whitehouse
ecc30c7915 [GFS2] Streamline indirect pointer tree height calculation
This patch improves the calculation of the tree height in order to reduce
the number of operations which are carried out on each call to gfs2_block_map.
In the common case, we now make a single comparison, rather than calculating
the required tree height from scratch each time. Also in the case that the
tree does need some extra height, we start from the current height rather from
zero when we work out what the new height ought to be.

In addition the di_height field is moved into the inode proper and reduced
in size to a u8 since the value must be between 0 and GFS2_MAX_META_HEIGHT (10).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:39:46 +01:00
Steven Whitehouse
941e6d7d09 [GFS2] Speed up gfs2_write_alloc_required, deprecate gfs2_extent_map
This patch removes the call to gfs2_extent_map from gfs2_write_alloc_required,
instead we call gfs2_block_map directly. This results in fewer overall calls
to gfs2_block_map in the multi-block case.

Also, gfs2_extent_map is marked as deprecated so that people know that its
going away as soon as all the callers have been converted.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:39:44 +01:00