The issue scenario is as following:
When fallocating a very large disk space for a small file,
__ocfs2_extend_allocation attempts to get a very large transaction. For
some journal sizes, there may be not enough room for this transaction,
and the fallocate will fail.
The patch below extends & restarts the transaction as necessary while
allocating space, and should work with even the smallest journal. This
patch refers ext4 resize.
Test:
# mkfs.ocfs2 -b 4K -C 32K -T datafiles /dev/sdc
...(jounral size is 32M)
# mount.ocfs2 /dev/sdc /mnt/ocfs2/
# touch /mnt/ocfs2/1.log
# fallocate -o 0 -l 400G /mnt/ocfs2/1.log
fallocate: /mnt/ocfs2/1.log: fallocate failed: Cannot allocate memory
# tail -f /var/log/messages
[ 7372.278591] JBD: fallocate wants too many credits (2051 > 2048)
[ 7372.278597] (fallocate,6438,0):__ocfs2_extend_allocation:709 ERROR: status = -12
[ 7372.278603] (fallocate,6438,0):ocfs2_allocate_unwritten_extents:1504 ERROR: status = -12
[ 7372.278607] (fallocate,6438,0):__ocfs2_change_file_space:1955 ERROR: status = -12
^C
With this patch, the test works well.
Signed-off-by: Younger Liu <younger.liu@huawei.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert commit 40bd62eb7f ("fs/ocfs2/journal.h: add bits_wanted while
calculating credits in ocfs2_calc_extend_credits").
Unfortunately this change broke fallocate even if there is insufficient
disk space for the preallocation, which is a serious problem.
# df -h
/dev/sda8 22G 1.2G 21G 6% /ocfs2
# fallocate -o 0 -l 200M /ocfs2/testfile
fallocate: /ocfs2/test: fallocate failed: No space left on device
and a kernel warning:
CPU: 3 PID: 3656 Comm: fallocate Tainted: G W O 3.11.0-rc3 #2
Call Trace:
dump_stack+0x77/0x9e
warn_slowpath_common+0xc4/0x110
warn_slowpath_null+0x2a/0x40
start_this_handle+0x6c/0x640 [jbd2]
jbd2__journal_start+0x138/0x300 [jbd2]
jbd2_journal_start+0x23/0x30 [jbd2]
ocfs2_start_trans+0x166/0x300 [ocfs2]
__ocfs2_extend_allocation+0x38f/0xdb0 [ocfs2]
ocfs2_allocate_unwritten_extents+0x3c9/0x520
__ocfs2_change_file_space+0x5e0/0xa60 [ocfs2]
ocfs2_fallocate+0xb1/0xe0 [ocfs2]
do_fallocate+0x1cb/0x220
SyS_fallocate+0x6f/0xb0
system_call_fastpath+0x16/0x1b
JBD2: fallocate wants too many credits (51216 > 4381)
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While adding extends to a file, the credits are calculated incorrectly
and if the requested clusters is more than one (or more because we used
a conservative limit) then we run out of journal credits and we hit an
assert in journalling code.
The function parameter bits_wanted variable was not used at all.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Code cleanup: needs_checkpoint is assigned to but never used. Delete
the variable.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Jeff Liu <jeff.liu@oracle.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With indexed_dir enabled, ocfs2 maintains a list of dirblocks having
space.
The credit calculation in ocfs2_link_credits() did not correctly account
for adding an entry that exactly fills a dirblock that triggers removing
that dirblock by changing the pointer in the previous block in the list.
The credit calculation did not account for that previous block.
To expose, do:
mkfs.ocfs2 -b 512 -M local /dev/sdX
mount /dev/sdX /ocfs2
mkdir /ocfs2/linkdir
touch /ocfs2/linkdir/file1
for i in `seq 1 29` ; do link /ocfs2/linkdir/file1
/ocfs2/linkdir/linklinklinklinklinklink$i; done
rm -f /ocfs2/linkdir/linklinklinklinklinklink10
sleep 8
link /ocfs2/linkdir/file1
/ocfs2/linkdir/linklinklinklinklinklinkaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Note:
The link names have been crafted for a 512 byte blocksize. Reproducing
with a larger blocksize will require longer (or more) links. The sleep
is important. We want jbd2 to commit the transaction so that the missing
block does not piggy back on account of the previous transaction.
Signed-off-by: XiaoweiHu <xiaowei.hu at oracle.com>
Reviewed-by: WengangWang <wen.gang.wang at oracle.com>
Reviewed-by: Sunil.Mushran <sunil.mushran at oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
In the rare case that INLINE_DATA, INDEX_DIR, QUOTA, XATTR features are
disabled and both the allocation of the directory inode and the allocation
of the first directory block need to relink allocation group, there need
not be enough credits reserved in a transaction. Fix the estimate.
CC: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
Thanks for the comments. I have incorportated them all.
CONFIG_OCFS2_FS_STATS is enabled and CONFIG_DEBUG_LOCK_ALLOC is disabled.
Statistics now look like -
ocfs2_write_ctxt: 2144 - 2136 = 8
ocfs2_inode_info: 1960 - 1848 = 112
ocfs2_journal: 168 - 160 = 8
ocfs2_lock_res: 336 - 304 = 32
ocfs2_refcount_tree: 512 - 472 = 40
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Rather than extending the transaction every time we add an extent to a
discontiguous block group, we grab enough credits to fill the extent
list up front. This means we can free the bits in the same transaction
if we end up not getting enough space.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
jbd[2]_journal_dirty_metadata() only returns 0. It's been returning 0
since before the kernel moved to git. There is no point in checking
this error.
ocfs2_journal_dirty() has been faithfully returning the status since the
beginning. All over ocfs2, we have blocks of code checking this can't
fail status. In the past few years, we've tried to avoid adding these
checks, because they are pointless. But anyone who looks at our code
assumes they are needed.
Finally, ocfs2_journal_dirty() is made a void function. All error
checking is removed from other files. We'll BUG_ON() the status of
jbd2_journal_dirty_metadata() just in case they change it someday. They
won't.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Add 'Decrement refcount for delete' in to the normal truncate
process. So for a refcounted extent record, call refcount rec
decrementation instead of cluster free.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
The next step in divorcing metadata I/O management from struct inode is
to pass struct ocfs2_caching_info to the journal functions. Thus the
journal locks a metadata cache with the cache io_lock function. It also
can compare ci_last_trans and ci_created_trans directly.
This is a large patch because of all the places we change
ocfs2_journal_access..(handle, inode, ...) to
ocfs2_journal_access..(handle, INODE_CACHE(inode), ...).
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Similar ip_last_trans, ip_created_trans tracks the creation of a journal
managed inode. This specifically tracks what transaction created the
inode. This is so the code can know if the inode has ever been written
to disk.
This behavior is desirable for any journal managed object. We move it
to struct ocfs2_caching_info as ci_created_trans so that any object
using ocfs2_caching_info can rely on this behavior.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We have the read side of metadata caching isolated to struct
ocfs2_caching_info, now we need the write side. This means the journal
functions. The journal only does a couple of things with struct inode.
This change moves the ip_last_trans field onto struct
ocfs2_caching_info as ci_last_trans. This field tells the journal
whether a pending journal flush is required.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
In OCFS2, allocator locks rank above transaction start. Thus we
cannot extend quota file from inside a transaction less we could
deadlock.
We solve the problem by starting transaction not already in
ocfs2_acquire_dquot() but only in ocfs2_local_read_dquot() and
ocfs2_global_read_dquot() and we allocate blocks to quota files before starting
the transaction. In case we crash, quota files will just have a few blocks
more but that's no problem since we just use them next time we extend the
quota file.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Numbers of needed credits for some quota operations were written
as raw numbers. Create appropriate defines instead.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
If the mount fails for any reason, ocfs2_dismount_volume calls
ocfs2_orphan_scan_stop. It requires that ocfs2_orphan_scan_init
be called to setup the mutex and work queues, but that doesn't
happen if the mount has failed and we oops accessing an uninitialized
work queue.
This patch splits the init and startup of the orphan scan, eliminating
the oops.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Local and Hard-RO mounts do not need orphan scanning.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
When a dentry is unlinked, the unlinking node takes an EX on the dentry lock
before moving the dentry to the orphan directory. Other nodes that have
this dentry in cache have a PR on the same dentry lock. When the EX is
requested, the other nodes flag the corresponding inode as MAYBE_ORPHANED
during downconvert. The inode is finally deleted when the last node to iput
the inode sees that i_nlink==0 and the MAYBE_ORPHANED flag is set.
A problem arises if a node is forced to free dentry locks because of memory
pressure. If this happens, the node will no longer get downconvert
notifications for the dentries that have been unlinked on another node.
If it also happens that node is actively using the corresponding inode and
happens to be the one performing the last iput on that inode, it will fail
to delete the inode as it will not have the MAYBE_ORPHANED flag set.
This patch fixes this shortcoming by introducing a periodic scan of the
orphan directories to delete such inodes. Care has been taken to distribute
the workload across the cluster so that no one node has to perform the task
all the time.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The ocfs2 directory index updates two blocks when we remove an entry -
the dx root and the dx leaf. OCFS2_DELETE_INODE_CREDITS was only
accounting for the dx leaf. This shows up when ocfs2_delete_inode()
runs out of credits in jbd2_journal_dirty_metadata() at
"J_ASSERT_JH(jh, handle->h_buffer_credits > 0);".
The test that caught this was running dirop_file_racer from the
ocfs2-test suite with a 250-character filename PREFIX. Run on a 512B
blocksize, it forces the orphan dir index to grow large enough to
trigger.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
During recovery, a node recovers orphans in it's slot and the dead node(s). But
if the dead nodes were holding orphans in offline slots, they will be left
unrecovered.
If the dead node is the last one to die and is holding orphans in other slots
and is the first one to mount, then it only recovers it's own slot, which
leaves orphans in offline slots.
This patch queues complete_recovery to clean orphans for all offline slots
during mount and node recovery.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The only operation which doesn't get faster with directory indexing is
insert, which still has to walk the entire unindexed directory portion to
find a free block. This patch provides an improvement in directory insert
performance by maintaining a singly linked list of directory leaf blocks
which have space for additional dirents.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Allow us to store a small number of directory index records in the
ocfs2_dx_root_block. This saves us a disk read on small to medium sized
directories (less than about 250 entries). The inline root is automatically
turned into a root block with extents if the directory size increases beyond
it's capacity.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
This patch makes use of Ocfs2's flexible btree code to add an additional
tree to directory inodes. The new tree stores an array of small,
fixed-length records in each leaf block. Each record stores a hash value,
and pointer to a block in the traditional (unindexed) directory tree where a
dirent with the given name hash resides. Lookup exclusively uses this tree
to find dirents, thus providing us with constant time name lookups.
Some of the hashing code was copied from ext3. Unfortunately, it has lots of
unfixed checkpatch errors. I left that as-is so that tracking changes would
be easier.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Move the definition of struct recovery_map from journal.c to journal.h. This
is preparation for the next patch.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
If we race with commit code setting i_transaction to NULL, we could
possibly dereference it. Proper locking requires the journal pointer
(to access journal->j_list_lock), which we don't have. So we have to
change the prototype of the function so that filesystem passes us the
journal pointer. Also add a more detailed comment about why the
function jbd2_journal_begin_ordered_truncate() does what it does and
how it should be used.
Thanks to Dan Carpenter <error27@gmail.com> for pointing to the
suspitious code.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Joel Becker <joel.becker@oracle.com>
CC: linux-ext4@vger.kernel.org
CC: ocfs2-devel@oss.oracle.com
CC: mfasheh@suse.de
CC: Dan Carpenter <error27@gmail.com>
The per-metadata-type ocfs2_journal_access_*() functions hook up jbd2
commit triggers and allow us to compute metadata ecc right before the
buffers are written out. This commit provides ecc for inodes, extent
blocks, group descriptors, and quota blocks. It is not safe to use
extened attributes and metaecc at the same time yet.
The ocfs2_extent_tree and ocfs2_path abstractions in alloc.c both hide
the type of block at their root. Before, it didn't matter, but now the
root block must use the appropriate ocfs2_journal_access_*() function.
To keep this abstract, the structures now have a pointer to the matching
journal_access function and a wrapper call to call it.
A few places use naked ocfs2_write_block() calls instead of adding the
blocks to the journal. We make sure to calculate their checksum and ecc
before the write.
Since we pass around the journal_access functions. Let's typedef them
in ocfs2.h.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
We create wrappers for ocfs2_journal_access() that are specific to the
type of metadata block. This allows us to associate jbd2 commit
triggers with the block. The triggers will compute metadata ecc in a
future commit.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Implement functions for recovery after a crash. Functions just
read local quota file and sync info to global quota file.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Add quota calls for allocation and freeing of inodes and space, also update
estimates on number of needed credits for a transaction. Move out inode
allocation from ocfs2_mknod_locked() because vfs_dq_init() must be called
outside of a transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
JBD2 is fully backwards compatible with JBD and it's been tested enough with
Ocfs2 that we can clean this code up now.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2 wants JBD2 for many reasons, not the least of which is that JBD is
limiting our maximum filesystem size.
It's a pretty trivial change. Most functions are just renamed. The
only functional change is moving to Jan's inode-based ordered data mode.
It's better, too.
Because JBD2 reads and writes JBD journals, this is compatible with any
existing filesystem. It can even interact with JBD-based ocfs2 as long
as the journal is formated for JBD.
We provide a compatibility option so that paranoid people can still use
JBD for the time being. This will go away shortly.
[ Moved call of ocfs2_begin_ordered_truncate() from ocfs2_delete_inode() to
ocfs2_truncate_for_delete(). --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch implements storing extended attributes both in inode or a single
external block. We only store EA's in-inode when blocksize > 512 or that
inode block has free space for it. When an EA's value is larger than 80
bytes, we will store the value via b-tree outside inode or block.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2_extend_meta_needed(), ocfs2_calc_extend_credits() and
ocfs2_reserve_new_metadata() are all useful for extent tree operations. But
they are all limited to an inode btree because they use a struct
ocfs2_dinode parameter. Change their parameter to struct ocfs2_extent_list
(the part of an ocfs2_dinode they actually use) so that the xattr btree code
can use these functions.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
As the fs recovery is asynchronous, there is a small chance that another
node can mount (and thus recover) the slot before the recovery thread
gets to it.
If this happens, the recovery thread will block indefinitely on the
journal/slot lock as that lock will be held for the duration of the mount
(by design) by the node assigned to that slot.
The solution implemented is to keep track of the journal replays using
a recovery generation in the journal inode, which will be incremented by the
thread replaying that journal. The recovery thread, before attempting the
blocking lock on the journal/slot lock, will compare the generation on disk
with what it has cached and skip recovery if it does not match.
This bug appears to have been inadvertently introduced during the mount/umount
vote removal by mainline commit 34d024f843. In the
mount voting scheme, the messaging would indirectly indicate that the slot
was being recovered.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The old recovery map was a bitmap of node numbers. This was sufficient
for the maximum node number of 254. Going forward, we want node numbers
to be UINT32. Thus, we need a new recovery map.
Note that we can't keep track of slots here. We must write down the
node number to recovery *before* we get the locks needed to convert a
node number into a slot number.
The recovery map is now an array of unsigned ints, max_slots in size.
It moves to journal.c with the rest of recovery.
Because it needs to be initialized, we move all of recovery initialization
into a new function, ocfs2_recovery_init(). This actually cleans up
ocfs2_initialize_super() a little as well. Following on, recovery cleaup
becomes part of ocfs2_recovery_exit().
A number of node map functions are rendered obsolete and are removed.
Finally, waiting on recovery is wrapped in a function rather than naked
checks on the recovery_event. This is a cleanup from Mark.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch adds the ability for a userspace program to request that a
properly formatted cluster group be added to the main allocation bitmap for
an Ocfs2 file system. The request is made via an ioctl, OCFS2_IOC_GROUP_ADD.
On a high level, this is similar to ext3, but we use a different ioctl as
the structure which has to be passed through is different.
During an online resize, tunefs.ocfs2 will format any new cluster groups
which must be added to complete the resize, and call OCFS2_IOC_GROUP_ADD on
each one. Kernel verifies that the core cluster group information is valid
and then does the work of linking it into the global allocation bitmap.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This patch adds the ability for a userspace program to request an extend of
last cluster group on an Ocfs2 file system. The request is made via ioctl,
OCFS2_IOC_GROUP_EXTEND. This is derived from EXT3_IOC_GROUP_EXTEND, but is
obviously Ocfs2 specific.
tunefs.ocfs2 would call this for an online-resize operation if the last
cluster group isn't full.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@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: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Joel Becker <joel.becker@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: Mark 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: Mark Fasheh <mark.fasheh@oracle.com>
Commit 592282cf2e fixed some missing directory
c/mtime updates in part by introducing a dinode update in ocfs2_add_entry().
Unfortunately, ocfs2_link() (which didn't update the directory inode before)
is now missing a single journal credit. Fix this by doubling the number of
inode updates expected during hard link creation.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This allows users to format an ocfs2 file system with a special flag,
OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT. When the file system sees this flag, it
will not use any cluster services, nor will it require a cluster
configuration, thus acting like a 'local' file system.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Conflicts:
drivers/ata/libata-scsi.c
include/linux/libata.h
Futher merge of Linus's head and compilation fixups.
Signed-Off-By: David Howells <dhowells@redhat.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: Mark 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: Mark Fasheh <mark.fasheh@oracle.com>