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ocfs2: Decrement refcount when truncating refcounted extents.

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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>
This commit is contained in:
Tao Ma
2009-08-18 11:29:12 +08:00
committed by Joel Becker
parent 1aa75fea64
commit bcbbb24a6a
4 changed files with 290 additions and 7 deletions
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212
fs/ocfs2/refcounttree.c
View File

@@ -2192,3 +2192,215 @@ static int ocfs2_mark_extent_refcounted(struct inode *inode,
out:
return ret;
}
/*
* Given some contiguous physical clusters, calculate what we need
* for modifying their refcount.
*/
static int ocfs2_calc_refcount_meta_credits(struct super_block *sb,
struct ocfs2_caching_info *ci,
struct buffer_head *ref_root_bh,
u64 start_cpos,
u32 clusters,
int *meta_add,
int *credits)
{
int ret = 0, index, ref_blocks = 0, recs_add = 0;
u64 cpos = start_cpos;
struct ocfs2_refcount_block *rb;
struct ocfs2_refcount_rec rec;
struct buffer_head *ref_leaf_bh = NULL, *prev_bh = NULL;
u32 len;
mlog(0, "start_cpos %llu, clusters %u\n",
(unsigned long long)start_cpos, clusters);
while (clusters) {
ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
cpos, clusters, &rec,
&index, &ref_leaf_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
if (ref_leaf_bh != prev_bh) {
/*
* Now we encounter a new leaf block, so calculate
* whether we need to extend the old leaf.
*/
if (prev_bh) {
rb = (struct ocfs2_refcount_block *)
prev_bh->b_data;
if (le64_to_cpu(rb->rf_records.rl_used) +
recs_add >
le16_to_cpu(rb->rf_records.rl_count))
ref_blocks++;
}
recs_add = 0;
*credits += 1;
brelse(prev_bh);
prev_bh = ref_leaf_bh;
get_bh(prev_bh);
}
rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
mlog(0, "recs_add %d,cpos %llu, clusters %u, rec->r_cpos %llu,"
"rec->r_clusters %u, rec->r_refcount %u, index %d\n",
recs_add, (unsigned long long)cpos, clusters,
(unsigned long long)le64_to_cpu(rec.r_cpos),
le32_to_cpu(rec.r_clusters),
le32_to_cpu(rec.r_refcount), index);
len = min((u64)cpos + clusters, le64_to_cpu(rec.r_cpos) +
le32_to_cpu(rec.r_clusters)) - cpos;
/*
* If the refcount rec already exist, cool. We just need
* to check whether there is a split. Otherwise we just need
* to increase the refcount.
* If we will insert one, increases recs_add.
*
* We record all the records which will be inserted to the
* same refcount block, so that we can tell exactly whether
* we need a new refcount block or not.
*/
if (rec.r_refcount) {
/* Check whether we need a split at the beginning. */
if (cpos == start_cpos &&
cpos != le64_to_cpu(rec.r_cpos))
recs_add++;
/* Check whether we need a split in the end. */
if (cpos + clusters < le64_to_cpu(rec.r_cpos) +
le32_to_cpu(rec.r_clusters))
recs_add++;
} else
recs_add++;
brelse(ref_leaf_bh);
ref_leaf_bh = NULL;
clusters -= len;
cpos += len;
}
if (prev_bh) {
rb = (struct ocfs2_refcount_block *)prev_bh->b_data;
if (le64_to_cpu(rb->rf_records.rl_used) + recs_add >
le16_to_cpu(rb->rf_records.rl_count))
ref_blocks++;
*credits += 1;
}
if (!ref_blocks)
goto out;
mlog(0, "we need ref_blocks %d\n", ref_blocks);
*meta_add += ref_blocks;
*credits += ref_blocks;
/*
* So we may need ref_blocks to insert into the tree.
* That also means we need to change the b-tree and add that number
* of records since we never merge them.
* We need one more block for expansion since the new created leaf
* block is also full and needs split.
*/
rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL) {
struct ocfs2_extent_tree et;
ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
*meta_add += ocfs2_extend_meta_needed(et.et_root_el);
*credits += ocfs2_calc_extend_credits(sb,
et.et_root_el,
ref_blocks);
} else {
*credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
*meta_add += 1;
}
out:
brelse(ref_leaf_bh);
brelse(prev_bh);
return ret;
}
/*
* For refcount tree, we will decrease some contiguous clusters
* refcount count, so just go through it to see how many blocks
* we gonna touch and whether we need to create new blocks.
*
* Normally the refcount blocks store these refcount should be
* continguous also, so that we can get the number easily.
* As for meta_ac, we will at most add split 2 refcount record and
* 2 more refcount block, so just check it in a rough way.
*
* Caller must hold refcount tree lock.
*/
int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
struct buffer_head *di_bh,
u64 phys_blkno,
u32 clusters,
int *credits,
struct ocfs2_alloc_context **meta_ac)
{
int ret, ref_blocks = 0;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct buffer_head *ref_root_bh = NULL;
struct ocfs2_refcount_tree *tree;
u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno);
if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
"tree, but the feature bit is not set in the "
"super block.", inode->i_ino);
ret = -EROFS;
goto out;
}
BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb),
le64_to_cpu(di->i_refcount_loc), &tree);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_read_refcount_block(&tree->rf_ci,
le64_to_cpu(di->i_refcount_loc),
&ref_root_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
&tree->rf_ci,
ref_root_bh,
start_cpos, clusters,
&ref_blocks, credits);
if (ret) {
mlog_errno(ret);
goto out;
}
mlog(0, "reserve new metadata %d, credits = %d\n",
ref_blocks, *credits);
if (ref_blocks) {
ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
ref_blocks, meta_ac);
if (ret)
mlog_errno(ret);
}
out:
brelse(ref_root_bh);
return ret;
}