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ocfs2: Abstract ocfs2_extent_tree in b-tree operations.

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In the old extent tree operation, we take the hypothesis that we
are using the ocfs2_extent_list in ocfs2_dinode as the tree root.
As xattr will also use ocfs2_extent_list to store large value
for a xattr entry, we refactor the tree operation so that xattr
can use it directly.

The refactoring includes 4 steps:
1. Abstract set/get of last_eb_blk and update_clusters since they may
   be stored in different location for dinode and xattr.
2. Add a new structure named ocfs2_extent_tree to indicate the
   extent tree the operation will work on.
3. Remove all the use of fe_bh and di, use root_bh and root_el in
   extent tree instead. So now all the fe_bh is replaced with
   et->root_bh, el with root_el accordingly.
4. Make ocfs2_lock_allocators generic. Now it is limited to be only used
   in file extend allocation. But the whole function is useful when we want
   to store large EAs.

Note: This patch doesn't touch ocfs2_commit_truncate() since it is not used
for anything other than truncate inode data btrees.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This commit is contained in:
Tao Ma
2008-08-18 17:38:44 +08:00
committed by Mark Fasheh
parent 811f933df1
commit e7d4cb6bc1
8 changed files with 456 additions and 288 deletions
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82
fs/ocfs2/suballoc.c
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@@ -1894,3 +1894,85 @@ static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
(unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
}
}
/*
* For a given allocation, determine which allocators will need to be
* accessed, and lock them, reserving the appropriate number of bits.
*
* Sparse file systems call this from ocfs2_write_begin_nolock()
* and ocfs2_allocate_unwritten_extents().
*
* File systems which don't support holes call this from
* ocfs2_extend_allocation().
*/
int ocfs2_lock_allocators(struct inode *inode, struct buffer_head *root_bh,
struct ocfs2_extent_list *root_el,
u32 clusters_to_add, u32 extents_to_split,
struct ocfs2_alloc_context **data_ac,
struct ocfs2_alloc_context **meta_ac)
{
int ret = 0, num_free_extents;
unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
*meta_ac = NULL;
if (data_ac)
*data_ac = NULL;
BUG_ON(clusters_to_add != 0 && data_ac == NULL);
num_free_extents = ocfs2_num_free_extents(osb, inode, root_bh,
OCFS2_DINODE_EXTENT);
if (num_free_extents < 0) {
ret = num_free_extents;
mlog_errno(ret);
goto out;
}
/*
* Sparse allocation file systems need to be more conservative
* with reserving room for expansion - the actual allocation
* happens while we've got a journal handle open so re-taking
* a cluster lock (because we ran out of room for another
* extent) will violate ordering rules.
*
* Most of the time we'll only be seeing this 1 cluster at a time
* anyway.
*
* Always lock for any unwritten extents - we might want to
* add blocks during a split.
*/
if (!num_free_extents ||
(ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
ret = ocfs2_reserve_new_metadata(osb, root_el, meta_ac);
if (ret < 0) {
if (ret != -ENOSPC)
mlog_errno(ret);
goto out;
}
}
if (clusters_to_add == 0)
goto out;
ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
if (ret < 0) {
if (ret != -ENOSPC)
mlog_errno(ret);
goto out;
}
out:
if (ret) {
if (*meta_ac) {
ocfs2_free_alloc_context(*meta_ac);
*meta_ac = NULL;
}
/*
* We cannot have an error and a non null *data_ac.
*/
}
return ret;
}