Commit Graph

13 Commits

Author SHA1 Message Date
Tristan Ye
78f94673d7 Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead.
Truncate is just a special case of punching holes(from new i_size to
end), we therefore could take advantage of the existing
ocfs2_remove_btree_range() to reduce the comlexity and redundancy in
alloc.c.  The goal here is to make truncate more generic and
straightforward.

Several functions only used by ocfs2_commit_truncate() will smiply be
removed.

ocfs2_remove_btree_range() was originally used by the hole punching
code, which didn't take refcount trees into account (definitely a bug).
We therefore need to change that func a bit to handle refcount trees.
It must take the refcount lock, calculate and reserve blocks for
refcount tree changes, and decrease refcounts at the end.  We replace 
ocfs2_lock_allocators() here by adding a new func
ocfs2_reserve_blocks_for_rec_trunc() which accepts some extra blocks to
reserve.  This will not hurt any other code using
ocfs2_remove_btree_range() (such as dir truncate and hole punching).

I merged the following steps into one patch since they may be
logically doing one thing, though I know it looks a little bit fat
to review.

1). Remove redundant code used by ocfs2_commit_truncate(), since we're
    moving to ocfs2_remove_btree_range anyway.

2). Add a new func ocfs2_reserve_blocks_for_rec_trunc() for purpose of
    accepting some extra blocks to reserve.

3). Change ocfs2_prepare_refcount_change_for_del() a bit to fit our
    needs.  It's safe to do this since it's only being called by
    truncate.

4). Change ocfs2_remove_btree_range() a bit to take refcount case into
    account.

5). Finally, we change ocfs2_commit_truncate() to call
    ocfs2_remove_btree_range() in a proper way.

The patch has been tested normally for sanity check, stress tests
with heavier workload will be expected.

Based on this patch, fixing the punching holes bug will be fairly easy.

Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-18 12:25:10 -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
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
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
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
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
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
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
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
8dec98edfe ocfs2: Add new refcount tree lock resource in dlmglue.
refcount tree lock resource is used to protect refcount
tree read/write among multiple nodes.

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