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ocfs2: Add normal functions for reflink a normal file's extents.
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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>
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Tao Ma authored and Joel Becker committed Sep 23, 2009
1 parent 37f8a2b commit 110a045
Showing 1 changed file with 286 additions and 0 deletions.
286 changes: 286 additions & 0 deletions fs/ocfs2/refcounttree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3282,3 +3282,289 @@ int ocfs2_refcount_cow(struct inode *inode,

return ret;
}

/*
* Insert a new extent into refcount tree and mark a extent rec
* as refcounted in the dinode tree.
*/
int ocfs2_add_refcount_flag(struct inode *inode,
struct ocfs2_extent_tree *data_et,
struct ocfs2_caching_info *ref_ci,
struct buffer_head *ref_root_bh,
u32 cpos, u32 p_cluster, u32 num_clusters,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int ret;
handle_t *handle;
int credits = 1, ref_blocks = 0;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_alloc_context *meta_ac = NULL;

ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
ref_ci, ref_root_bh,
p_cluster, num_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);
goto out;
}
}

handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out;
}

ret = ocfs2_mark_extent_refcounted(inode, data_et, handle,
cpos, num_clusters, p_cluster,
meta_ac, dealloc);
if (ret) {
mlog_errno(ret);
goto out_commit;
}

ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
p_cluster, num_clusters,
meta_ac, dealloc);
if (ret)
mlog_errno(ret);

out_commit:
ocfs2_commit_trans(osb, handle);
out:
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
return ret;
}

static int ocfs2_attach_refcount_tree(struct inode *inode,
struct buffer_head *di_bh)
{
int ret;
struct buffer_head *ref_root_bh = NULL;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_refcount_tree *ref_tree;
unsigned int ext_flags;
loff_t size;
u32 cpos, num_clusters, clusters, p_cluster;
struct ocfs2_cached_dealloc_ctxt dealloc;
struct ocfs2_extent_tree di_et;

ocfs2_init_dealloc_ctxt(&dealloc);

if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)) {
ret = ocfs2_create_refcount_tree(inode, di_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
}

BUG_ON(!di->i_refcount_loc);
ret = ocfs2_lock_refcount_tree(osb,
le64_to_cpu(di->i_refcount_loc), 1,
&ref_tree, &ref_root_bh);
if (ret) {
mlog_errno(ret);
goto out;
}

ocfs2_init_dinode_extent_tree(&di_et, INODE_CACHE(inode), di_bh);

size = i_size_read(inode);
clusters = ocfs2_clusters_for_bytes(inode->i_sb, size);

cpos = 0;
while (cpos < clusters) {
ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
&num_clusters, &ext_flags);

if (p_cluster && !(ext_flags & OCFS2_EXT_REFCOUNTED)) {
ret = ocfs2_add_refcount_flag(inode, &di_et,
&ref_tree->rf_ci,
ref_root_bh, cpos,
p_cluster, num_clusters,
&dealloc);
if (ret) {
mlog_errno(ret);
break;
}
}
cpos += num_clusters;
}

ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
brelse(ref_root_bh);

if (!ret && ocfs2_dealloc_has_cluster(&dealloc)) {
ocfs2_schedule_truncate_log_flush(osb, 1);
ocfs2_run_deallocs(osb, &dealloc);
}
out:
/*
* Empty the extent map so that we may get the right extent
* record from the disk.
*/
ocfs2_extent_map_trunc(inode, 0);

return ret;
}

static int ocfs2_add_refcounted_extent(struct inode *inode,
struct ocfs2_extent_tree *et,
struct ocfs2_caching_info *ref_ci,
struct buffer_head *ref_root_bh,
u32 cpos, u32 p_cluster, u32 num_clusters,
unsigned int ext_flags,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int ret;
handle_t *handle;
int credits = 0;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_alloc_context *meta_ac = NULL;

ret = ocfs2_lock_refcount_allocators(inode->i_sb,
p_cluster, num_clusters,
et, ref_ci,
ref_root_bh, &meta_ac,
NULL, &credits);
if (ret) {
mlog_errno(ret);
goto out;
}

handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out;
}

ret = ocfs2_insert_extent(handle, et, cpos,
cpu_to_le64(ocfs2_clusters_to_blocks(inode->i_sb,
p_cluster)),
num_clusters, ext_flags, meta_ac);
if (ret) {
mlog_errno(ret);
goto out_commit;
}

ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
p_cluster, num_clusters,
meta_ac, dealloc);
if (ret)
mlog_errno(ret);

out_commit:
ocfs2_commit_trans(osb, handle);
out:
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
return ret;
}

static int ocfs2_duplicate_extent_list(struct inode *s_inode,
struct inode *t_inode,
struct buffer_head *t_bh,
struct ocfs2_caching_info *ref_ci,
struct buffer_head *ref_root_bh,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int ret = 0;
u32 p_cluster, num_clusters, clusters, cpos;
loff_t size;
unsigned int ext_flags;
struct ocfs2_extent_tree et;

ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(t_inode), t_bh);

size = i_size_read(s_inode);
clusters = ocfs2_clusters_for_bytes(s_inode->i_sb, size);

cpos = 0;
while (cpos < clusters) {
ret = ocfs2_get_clusters(s_inode, cpos, &p_cluster,
&num_clusters, &ext_flags);

if (p_cluster) {
ret = ocfs2_add_refcounted_extent(t_inode, &et,
ref_ci, ref_root_bh,
cpos, p_cluster,
num_clusters,
ext_flags,
dealloc);
if (ret) {
mlog_errno(ret);
goto out;
}
}

cpos += num_clusters;
}

out:
return ret;
}

static int ocfs2_create_reflink_node(struct inode *s_inode,
struct buffer_head *s_bh,
struct inode *t_inode,
struct buffer_head *t_bh)
{
int ret;
struct buffer_head *ref_root_bh = NULL;
struct ocfs2_cached_dealloc_ctxt dealloc;
struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
struct ocfs2_refcount_block *rb;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)s_bh->b_data;
struct ocfs2_refcount_tree *ref_tree;

ocfs2_init_dealloc_ctxt(&dealloc);

ret = ocfs2_set_refcount_tree(t_inode, t_bh,
le64_to_cpu(di->i_refcount_loc));
if (ret) {
mlog_errno(ret);
goto out;
}

ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
1, &ref_tree, &ref_root_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;

ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,
&ref_tree->rf_ci, ref_root_bh,
&dealloc);
if (ret)
mlog_errno(ret);

ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
brelse(ref_root_bh);
out:
if (ocfs2_dealloc_has_cluster(&dealloc)) {
ocfs2_schedule_truncate_log_flush(osb, 1);
ocfs2_run_deallocs(osb, &dealloc);
}

return ret;
}

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