Commit Graph

1052 Commits

Author SHA1 Message Date
Coly Li
837711f862 ocfs2: return f_fsid info in ocfs2_statfs()
Currently the f_fsid of struct kstatfs returned from ocfs2_statfs() is
undefined (vfs layer fills in 0 as default). Since in some conditions,
f_fsid value might be used in a (f_fsid, ino) pair to uniquely identify
a file, ocfs2 should return a unique defined f_fsid value from
ocfs2_statfs().

Because uuid_str is the same on big or litlle endian machine, it's
endian consistent to use osb->uuid_str to generate f_fsid value.

Signed-off-by: Coly Li <coly.li@suse.de>
Cc: Sunil Mushran <sunil.mushran@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-10-29 15:02:20 -07:00
Tao Ma
2f48d593b6 ocfs2: duplicate inline data properly during reflink.
The old reflink fails to handle inodes with inline data and will oops
if it encounters them.  This patch copies inline data to the new inode.
Extended attributes may still be refcounted.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Tested-by: Tristan Ye <tristan.ye@oracle.com>
2009-10-28 22:48:23 -07:00
Tao Ma
87f4b1bb98 ocfs2: Move ocfs2_complete_reflink to the right place.
As its name ocfs2_complete_reflink indicates, it should
be called after all the work for reflink is done, so
it really should be called after we reflink xattr
successfully.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Tested-by: Tristan Ye <tristan.ye@oracle.com>
2009-10-28 22:44:19 -07:00
Joel Becker
fb5cbe9efd ocfs2: Return -EINVAL when a device is not ocfs2.
In case of non-modular kernels the root filesystem is mounted by trying
several filesystems. If ocfs2 was tried before the actual filesystem
type, the mount would fail because ocfs2_sb_probe() returns -EAGAIN
instead of -EINVAL.  ocfs2 will now return -EINVAL properly.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Reported-by: Laszlo Attila Toth <panther@balabit.hu>
2009-10-28 22:28:24 -07:00
Alexey Dobriyan
828c09509b const: constify remaining file_operations
[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:11 -07:00
Alexey Dobriyan
f0f37e2f77 const: mark struct vm_struct_operations
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 11:39:25 -07:00
Linus Torvalds
db16826367 Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
  HWPOISON: Enable error_remove_page on btrfs
  HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
  HWPOISON: Add madvise() based injector for hardware poisoned pages v4
  HWPOISON: Enable error_remove_page for NFS
  HWPOISON: Enable .remove_error_page for migration aware file systems
  HWPOISON: The high level memory error handler in the VM v7
  HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
  HWPOISON: shmem: call set_page_dirty() with locked page
  HWPOISON: Define a new error_remove_page address space op for async truncation
  HWPOISON: Add invalidate_inode_page
  HWPOISON: Refactor truncate to allow direct truncating of page v2
  HWPOISON: check and isolate corrupted free pages v2
  HWPOISON: Handle hardware poisoned pages in try_to_unmap
  HWPOISON: Use bitmask/action code for try_to_unmap behaviour
  HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
  HWPOISON: Add poison check to page fault handling
  HWPOISON: Add basic support for poisoned pages in fault handler v3
  HWPOISON: Add new SIGBUS error codes for hardware poison signals
  HWPOISON: Add support for poison swap entries v2
  HWPOISON: Export some rmap vma locking to outside world
  ...
2009-09-24 07:53:22 -07:00
Alexey Dobriyan
2bcd57ab61 headers: utsname.h redux
* remove asm/atomic.h inclusion from linux/utsname.h --
   not needed after kref conversion
 * remove linux/utsname.h inclusion from files which do not need it

NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 18:13:10 -07:00
Linus Torvalds
b64ada6b23 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (85 commits)
  ocfs2: Use buffer IO if we are appending a file.
  ocfs2: add spinlock protection when dealing with lockres->purge.
  dlmglue.c: add missed mlog lines
  ocfs2: __ocfs2_abort() should not enable panic for local mounts
  ocfs2: Add ioctl for reflink.
  ocfs2: Enable refcount tree support.
  ocfs2: Implement ocfs2_reflink.
  ocfs2: Add preserve to reflink.
  ocfs2: Create reflinked file in orphan dir.
  ocfs2: Use proper parameter for some inode operation.
  ocfs2: Make transaction extend more efficient.
  ocfs2: Don't merge in 1st refcount ops of reflink.
  ocfs2: Modify removing xattr process for refcount.
  ocfs2: Add reflink support for xattr.
  ocfs2: Create an xattr indexed block if needed.
  ocfs2: Call refcount tree remove process properly.
  ocfs2: Attach xattr clusters to refcount tree.
  ocfs2: Abstract ocfs2 xattr tree extend rec iteration process.
  ocfs2: Abstract the creation of xattr block.
  ocfs2: Remove inode from ocfs2_xattr_bucket_get_name_value.
  ...
2009-09-23 09:29:20 -07:00
James Morris
88e9d34c72 seq_file: constify seq_operations
Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.

This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:29 -07:00
Tao Ma
b80474b432 ocfs2: Use buffer IO if we are appending a file.
In ocfs2_file_aio_write, we will prevent direct io if
we find that we are appending(changing i_size) and call
generic_file_aio_write_nolock. But actually O_DIRECT flag
is there and this function will call generic_file_direct_write
eventually which will update i_size and leave di->i_size
alone. The bug is
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1173.

So this patch let ocfs2_direct_IO returns 0 directly if we
are appending so that buffered write will be called and
di->i_size get updated successfully. And this is also
what we want in ocfs2_file_aio_write.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-09-23 01:54:49 -07:00
Wengang Wang
83e32d9044 ocfs2: add spinlock protection when dealing with lockres->purge.
when we check/modify lockres->purge, we should with the protection of lockres->spinlock.
in dlm_purge_lockres(), the checking/modifying is not with the protectin.
this patch fixes it.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-09-23 01:54:48 -07:00
Coly Li
d92bc5127b dlmglue.c: add missed mlog lines
This patch adds the missed mlog_exit() and mlog_exit_void() lines when routines
return.

Signed-off-by: Coly Li <coly.li@suse.de>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-09-23 01:54:47 -07:00
Sunil Mushran
a2f2ddbf2b ocfs2: __ocfs2_abort() should not enable panic for local mounts
In a clustered setup, we have to panic the box on journal abort. This is
because we don't have the facility to go hard readonly. With hard ro, another
node would detect node failure and initiate recovery.

Having said that, we shouldn't force panic if the volume is mounted locally.
This patch defers the handling to the mount option, errors.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-09-23 01:54:46 -07:00
Tao Ma
bd50873dc7 ocfs2: Add ioctl for reflink.
The ioctl will take 3 parameters: old_path, new_path and
preserve and call vfs_reflink. It is useful when we backport
reflink features to old kernels.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:51 -07:00
Tao Ma
64871b8d62 ocfs2: Enable refcount tree support.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:50 -07:00
Tao Ma
09bf27a000 ocfs2: Implement ocfs2_reflink.
Implement ocfs2_reflink.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:49 -07:00
Tao Ma
0fe9b66c65 ocfs2: Add preserve to reflink.
reflink has 2 options for the destination file:
1. snapshot: reflink will attempt to preserve ownership, permissions,
   and all other security state in order to create a full snapshot.
2. new file: it will acquire the data extent sharing but will see the
   file's security state and attributes initialized as a new file.

So add the option to ocfs2.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:49 -07:00
Tao Ma
bc13d34757 ocfs2: Create reflinked file in orphan dir.
reflink is a very complicated process, so it can't be integrated
into one transaction. So if the system panic in the operation, we
may leave a unfinished inode in the destication directory.

So we will try to create an inode in orphan_dir first, reflink it
to the src file and then move it to the destication file in the end.
In that way we won't be afraid of any corruption during the reflink.

This patch adds 2 functions for orphan_dir operation:
1. Create a new inode in orphand dir.
2. Move an inode to a target dir.

Note:
fsck.ocfs2 should work for us to remove the unfinished file in the
orphan_dir.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:48 -07:00
Tao Ma
19bd341f6a ocfs2: Use proper parameter for some inode operation.
In order to make the original function more suitable for reflink,
we modify the following inode operations. Both are tiny.

1. ocfs2_mknod_locked only use dentry for mlog, so move it to
   the caller so that reflink can use it without dentry.
2. ocfs2_prepare_orphan_dir only want inode to get its ip_blkno.
   So use ip_blkno instead.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:47 -07:00
Tao Ma
c18b812d12 ocfs2: Make transaction extend more efficient.
In ocfs2_extend_rotate_transaction, op_credits is the orignal
credits in the handle and we only want to extend the credits
for the rotation, but the old solution always double it. It
is harmless for some minor operations, but for actions like
reflink we may rotate tree many times and cause the credits
increase dramatically. So this patch try to only increase
the desired credits.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:46 -07:00
Tao Ma
7540c1a77b ocfs2: Don't merge in 1st refcount ops of reflink.
Actually the whole reflink will touch refcount tree 2 times:
1. It will add the clusters in the extent record to the tree if it
   isn't refcounted before.
2. It will add 1 refcount to these clusters when it add these
   extent records to the tree.

So actually we shouldn't do merge in the 1st operation since the 2nd
one will soon be called and we may have to split it again. Do a merge
first and split soon is a waste of time. So we only merge in the 2nd
round. This is done by adding a new internal __ocfs2_increase_refcount
and call it with "not-merge" for 1st refcount operation in reflink.

This also has a side-effect that we don't need to worry too much about
the metadata allocation in the 2nd round since it will only merge and
no split will happen for those records.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:46 -07:00
Tao Ma
ce9c5a54c0 ocfs2: Modify removing xattr process for refcount.
The old xattr value remove is quite simple, it just erase the
tree and free the clusters. But as we have added refcount support,
The process is a little complicated.

We have to lock the refcount tree at the beginning, what's more,
we may split the refcount tree in some cases, so meta/credits are
needed.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:45 -07:00
Tao Ma
2999d12f4d ocfs2: Add reflink support for xattr.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:45 -07:00
Tao Ma
a7fe7a3a1a ocfs2: Create an xattr indexed block if needed.
With reflink, there is a need that we create a new xattr indexed
block from the very beginning. So add a new parameter for
ocfs2_create_xattr_block.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:44 -07:00
Tao Ma
8b2c0dba51 ocfs2: Call refcount tree remove process properly.
Now with xattr refcount support, we need to check whether
we have xattr refcounted before we remove the refcount tree.

Now the mechanism is:
1) Check whether i_clusters == 0, if no, exit.
2) check whether we have i_xattr_loc in dinode. if yes, exit.
2) Check whether we have inline xattr stored outside, if yes, exit.
4) Remove the tree.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:44 -07:00
Tao Ma
0129241e2b ocfs2: Attach xattr clusters to refcount tree.
In ocfs2, when xattr's value is larger than OCFS2_XATTR_INLINE_SIZE,
it will be kept outside of the blocks we store xattr entry. And they
are stored in a b-tree also. So this patch try to attach all these
clusters to refcount tree also.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:43 -07:00
Tao Ma
47bca4950b ocfs2: Abstract ocfs2 xattr tree extend rec iteration process.
Currently we have ocfs2_iterate_xattr_buckets which can receive
a para and a callback to iterate a series of bucket. It is good.
But actually the 2 callers ocfs2_xattr_tree_list_index_block and
ocfs2_delete_xattr_index_block are almost the same. The only
difference is that the latter need to handle the extent record
also. So add a new function named ocfs2_iterate_xattr_index_block.
It can be given func callback which are used for exten record.
So now we only have one iteration function for the xattr index
block. Ane what's more, it is useful for our future reflink
operations.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:43 -07:00
Tao Ma
5aea1f0ef4 ocfs2: Abstract the creation of xattr block.
In xattr reflink, we also need to create xattr block, so
abstract the process out.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:42 -07:00
Tao Ma
fd68a894fc ocfs2: Remove inode from ocfs2_xattr_bucket_get_name_value.
In ocfs2_xattr_bucket_get_name_value, actually we only use
super_block. So use it.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:41 -07:00
Tao Ma
492a8a33e1 ocfs2: Add CoW support for xattr.
In order to make 2 transcation(xattr and cow) independent with each other,
we CoW the whole xattr out in case we are setting them.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:41 -07:00
Tao Ma
913580b4cd ocfs2: Abstract duplicate clusters process in CoW.
We currently use pagecache to duplicate clusters in CoW,
but it isn't suitable for xattr case. So abstract it out
so that the caller can decide which method it use.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:40 -07:00
Tao Ma
1061f9c1c9 ocfs2: Return extent flags for xattr value tree.
With the new refcount tree, xattr value can also be refcounted
among multiple files. So return the appropriate extent flags
so that CoW can used it later.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:39 -07:00
Tao Ma
a9063ab9a3 ocfs2: handle file attributes issue for reflink.
A reflink creates a snapshot of a file, that means the attributes
must be identical except for three exceptions - nlink, ino, and ctime.

As for time changes, Here is a brief description:

1. Source file:
   1) atime: Ignore. Let the lazy atime code handle that.
   2) mtime: don't touch.
   3) ctime: If we change the tree (adding REFCOUNTED to at least one
             extent), update it.
2. Destination file:
   1) atime: ignore.
   2) mtime: we want it to appear identical to the source.
   3) ctime: update.

The idea here is that an ls -l will show the same time for the
src and target - it shows mtime.  Backup software like rsync and tar
will treat the new file correctly too.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:39 -07:00
Tao Ma
110a045aca ocfs2: Add normal functions for reflink a normal file's extents.
2 major functions are added in this patch.

ocfs2_attach_refcount_tree will create a new refcount tree to the
old file if it doesn't have one and insert all the extent records
to the tree if they are not refcounted.

ocfs2_create_reflink_node will:
1. set the refcount tree to the new file.
2. call ocfs2_duplicate_extent_list which will iterate all the
   extents for the old file, insert it to the new file and increase
   the corresponding referennce count.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:38 -07:00
Tao Ma
37f8a2bfaa ocfs2: CoW a reflinked cluster when it is truncated.
When we truncate a file to a specific size which resides in a reflinked
cluster, we need to CoW it since ocfs2_zero_range_for_truncate will
zero the space after the size(just another type of write).

So we add a "max_cpos" in ocfs2_refcount_cow so that it will stop when
it hit the max cluster offset.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:38 -07:00
Tao Ma
293b2f70b4 ocfs2: Integrate CoW in file write.
When we use mmap, we CoW the refcountd clusters in
ocfs2_write_begin_nolock. While for normal file
io(including directio), we do CoW in
ocfs2_prepare_inode_for_write.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:37 -07:00
Tao Ma
6ae23c5555 ocfs2: CoW refcount tree improvement.
During CoW, if the old extent record is refcounted, we allocate
som new clusters and do CoW. Actually we can have some improvement
here. If the old extent has refcount=1, that means now it is only
used by this file. So we don't need to allocate new clusters, just
remove the refcounted flag and it is OK. We also have to remove
it from the refcount tree while not deleting it.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:36 -07:00
Tao Ma
6f70fa5199 ocfs2: Add CoW support.
This patch try CoW support for a refcounted record.

the whole process will be:
1. Calculate how many clusters we need to CoW and where we start.
   Extents that are not completely encompassed by the write will
   be broken on 1MB boundaries.
2. Do CoW for the clusters with the help of page cache.
3. Change the b-tree structure with the new allocated clusters.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:36 -07:00
Tao Ma
bcbbb24a6a ocfs2: Decrement refcount when truncating refcounted extents.
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>
2009-09-22 20:09:35 -07:00
Tao Ma
1aa75fea64 ocfs2: Add functions for extents refcounted.
Add function ocfs2_mark_extent_refcounted which can mark
an extent refcounted.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:34 -07:00
Tao Ma
1823cb0b9f ocfs2: Add support of decrementing refcount for delete.
Given a physical cpos and length, decrement the refcount
in the tree. If the refcount for any portion of the extent goes
to zero, that portion is queued for freeing.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:33 -07:00
Tao Ma
e73a819db9 ocfs2: Add support for incrementing refcount in the tree.
Given a physical cpos and length, increment the refcount
in the tree. If the extent has not been seen before, a refcount
record is created for it. Refcount records may be merged or
split by this operation.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:33 -07:00
Tao Ma
e2e9f6082b ocfs2: move tree path functions to alloc.h.
Now fs/ocfs2/alloc.c has more than 7000 lines. It contains our
basic b-tree operation. Although we have already make our b-tree
operation generic, the basic structrue ocfs2_path which is used
to iterate one b-tree branch is still static and limited to only
used in alloc.c. As refcount tree need them and I don't want to
add any more b-tree unrelated code to alloc.c, export them out.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:32 -07:00
Tao Ma
fe92441595 ocfs2: Add refcount b-tree as a new extent tree.
Add refcount b-tree as a new extent tree so that it can
use the b-tree to store and maniuplate ocfs2_refcount_rec.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:31 -07:00
Tao Ma
555936bfcb ocfs2: Abstract extent split process.
ocfs2_mark_extent_written actually does the following things:
1. check the parameters.
2. initialize the left_path and split_rec.
3. call __ocfs2_mark_extent_written. it will do:
   1) check the flags of unwritten
   2) do the real split work.
The whole process is packed tightly somehow. So this patch
will abstract 2 different functions so that future b-tree
operation can work with it.

1. __ocfs2_split_extent will accept path and split_rec and do
  the real split work.
2. ocfs2_change_extent_flag will accept a new flag and initialize
   path and split_rec.

So now ocfs2_mark_extent_written will do:
1. check the parameters.
2. call ocfs2_change_extent_flag.
   1) initalize the left_path and split_rec.
   2) check whether the new flags conflict with the old one.
   3) call __ocfs2_split_extent to do the split.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:31 -07:00
Tao Ma
853a3a1439 ocfs2: Wrap ocfs2_extent_contig in ocfs2_extent_tree.
Add a new operation eo_ocfs2_extent_contig int the extent tree's
operations vector. So that with the new refcount tree, We want
this so that refcount trees can always return CONTIG_NONE and
prevent extent merging.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:30 -07:00
Tao Ma
8bf396de98 ocfs2: Basic tree root operation.
Add basic refcount tree root operation.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:30 -07:00
Tao Ma
374a263e79 ocfs2: Add refcount tree lock mechanism.
Implement locking around struct ocfs2_refcount_tree.  This protects
all read/write operations on refcount trees.  ocfs2_refcount_tree
has its own lock and its own caching_info, protecting buffers among
multiple nodes.

User must call ocfs2_lock_refcount_tree before his operation on
the tree and unlock it after that.

ocfs2_refcount_trees are referenced by the block number of the
refcount tree root block, So we create an rb-tree on the ocfs2_super
to look them up.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:29 -07:00
Tao Ma
c732eb16bf ocfs2: Add caching info for refcount tree.
refcount tree should use its own caching info so that when
we downconvert the refcount tree lock, we can drop all the
cached buffer head.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22 20:09:28 -07:00