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ocfs2: Optionally limit extent size in ocfs2_insert_extent()
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In xattr bucket, we want to limit the maximum size of a btree leaf,
otherwise we'll lose the benefits of hashing because we'll have to search
large leaves.

So add a new field in ocfs2_extent_tree which indicates the maximum leaf cluster
size we want so that we can prevent ocfs2_insert_extent() from merging the leaf
record even if it is contiguous with an adjacent record.

Other btree types are not affected by this change.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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Tao Ma authored and Mark Fasheh committed Oct 13, 2008
1 parent 589dc26 commit ca12b7c
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Showing 2 changed files with 35 additions and 9 deletions.
39 changes: 30 additions & 9 deletions fs/ocfs2/alloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -79,6 +79,7 @@ struct ocfs2_extent_tree {
struct buffer_head *root_bh;
struct ocfs2_extent_list *root_el;
void *private;
unsigned int max_leaf_clusters;
};

static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
Expand Down Expand Up @@ -220,7 +221,8 @@ static struct ocfs2_extent_tree_operations ocfs2_xattr_tree_et_ops = {
};

static struct ocfs2_extent_tree*
ocfs2_new_extent_tree(struct buffer_head *bh,
ocfs2_new_extent_tree(struct inode *inode,
struct buffer_head *bh,
enum ocfs2_extent_tree_type et_type,
void *private)
{
Expand Down Expand Up @@ -248,6 +250,8 @@ static struct ocfs2_extent_tree*
(struct ocfs2_xattr_block *)bh->b_data;
et->root_el = &xb->xb_attrs.xb_root.xt_list;
et->eops = &ocfs2_xattr_tree_et_ops;
et->max_leaf_clusters = ocfs2_clusters_for_bytes(inode->i_sb,
OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
}

return et;
Expand Down Expand Up @@ -4109,7 +4113,8 @@ ocfs2_figure_merge_contig_type(struct inode *inode, struct ocfs2_path *path,
static void ocfs2_figure_contig_type(struct inode *inode,
struct ocfs2_insert_type *insert,
struct ocfs2_extent_list *el,
struct ocfs2_extent_rec *insert_rec)
struct ocfs2_extent_rec *insert_rec,
struct ocfs2_extent_tree *et)
{
int i;
enum ocfs2_contig_type contig_type = CONTIG_NONE;
Expand All @@ -4125,6 +4130,20 @@ static void ocfs2_figure_contig_type(struct inode *inode,
}
}
insert->ins_contig = contig_type;

if (insert->ins_contig != CONTIG_NONE) {
struct ocfs2_extent_rec *rec =
&el->l_recs[insert->ins_contig_index];
unsigned int len = le16_to_cpu(rec->e_leaf_clusters) +
le16_to_cpu(insert_rec->e_leaf_clusters);

/*
* Caller might want us to limit the size of extents, don't
* calculate contiguousness if we might exceed that limit.
*/
if (et->max_leaf_clusters && len > et->max_leaf_clusters)
insert->ins_contig = CONTIG_NONE;
}
}

/*
Expand Down Expand Up @@ -4232,7 +4251,7 @@ static int ocfs2_figure_insert_type(struct inode *inode,
le16_to_cpu(el->l_next_free_rec);

if (!insert->ins_tree_depth) {
ocfs2_figure_contig_type(inode, insert, el, insert_rec);
ocfs2_figure_contig_type(inode, insert, el, insert_rec, et);
ocfs2_figure_appending_type(insert, el, insert_rec);
return 0;
}
Expand Down Expand Up @@ -4266,7 +4285,7 @@ static int ocfs2_figure_insert_type(struct inode *inode,
* into two types of appends: simple record append, or a
* rotate inside the tail leaf.
*/
ocfs2_figure_contig_type(inode, insert, el, insert_rec);
ocfs2_figure_contig_type(inode, insert, el, insert_rec, et);

/*
* The insert code isn't quite ready to deal with all cases of
Expand Down Expand Up @@ -4402,7 +4421,7 @@ int ocfs2_dinode_insert_extent(struct ocfs2_super *osb,
int status;
struct ocfs2_extent_tree *et = NULL;

et = ocfs2_new_extent_tree(root_bh, OCFS2_DINODE_EXTENT, NULL);
et = ocfs2_new_extent_tree(inode, root_bh, OCFS2_DINODE_EXTENT, NULL);
if (!et) {
status = -ENOMEM;
mlog_errno(status);
Expand Down Expand Up @@ -4433,7 +4452,8 @@ int ocfs2_xattr_value_insert_extent(struct ocfs2_super *osb,
int status;
struct ocfs2_extent_tree *et = NULL;

et = ocfs2_new_extent_tree(root_bh, OCFS2_XATTR_VALUE_EXTENT, private);
et = ocfs2_new_extent_tree(inode, root_bh,
OCFS2_XATTR_VALUE_EXTENT, private);
if (!et) {
status = -ENOMEM;
mlog_errno(status);
Expand Down Expand Up @@ -4463,7 +4483,8 @@ int ocfs2_xattr_tree_insert_extent(struct ocfs2_super *osb,
int status;
struct ocfs2_extent_tree *et = NULL;

et = ocfs2_new_extent_tree(root_bh, OCFS2_XATTR_TREE_EXTENT, NULL);
et = ocfs2_new_extent_tree(inode, root_bh, OCFS2_XATTR_TREE_EXTENT,
NULL);
if (!et) {
status = -ENOMEM;
mlog_errno(status);
Expand Down Expand Up @@ -4879,7 +4900,7 @@ int ocfs2_mark_extent_written(struct inode *inode, struct buffer_head *root_bh,
goto out;
}

et = ocfs2_new_extent_tree(root_bh, et_type, private);
et = ocfs2_new_extent_tree(inode, root_bh, et_type, private);
if (!et) {
ret = -ENOMEM;
mlog_errno(ret);
Expand Down Expand Up @@ -5177,7 +5198,7 @@ int ocfs2_remove_extent(struct inode *inode, struct buffer_head *root_bh,
struct ocfs2_path *path = NULL;
struct ocfs2_extent_tree *et = NULL;

et = ocfs2_new_extent_tree(root_bh, et_type, private);
et = ocfs2_new_extent_tree(inode, root_bh, et_type, private);
if (!et) {
ret = -ENOMEM;
mlog_errno(ret);
Expand Down
5 changes: 5 additions & 0 deletions fs/ocfs2/alloc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,11 @@ enum ocfs2_extent_tree_type {
OCFS2_XATTR_TREE_EXTENT,
};

/*
* For xattr tree leaf, we limit the leaf byte size to be 64K.
*/
#define OCFS2_MAX_XATTR_TREE_LEAF_SIZE 65536

struct ocfs2_alloc_context;
int ocfs2_dinode_insert_extent(struct ocfs2_super *osb,
handle_t *handle,
Expand Down

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