2009-03-24 14:18:41

by David Teigland

Subject: [PATCH 1/7] dlm: Change rwlock which is only used in write mode to a spinlock

From: Steven Whitehouse <[email protected]>

The ls_dirtbl[].lock was an rwlock, but since it was only used in write
mode a spinlock will suffice.

Signed-off-by: Steven Whitehouse <[email protected]>
Signed-off-by: David Teigland <[email protected]>
---
fs/dlm/dir.c | 18 +++++++++---------
fs/dlm/dlm_internal.h | 2 +-
fs/dlm/lockspace.c | 2 +-
3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/dlm/dir.c b/fs/dlm/dir.c
index 92969f8..858fba1 100644
--- a/fs/dlm/dir.c
+++ b/fs/dlm/dir.c
@@ -156,7 +156,7 @@ void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int namelen

bucket = dir_hash(ls, name, namelen);

- write_lock(&ls->ls_dirtbl[bucket].lock);
+ spin_lock(&ls->ls_dirtbl[bucket].lock);

de = search_bucket(ls, name, namelen, bucket);

@@ -173,7 +173,7 @@ void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int namelen
list_del(&de->list);
kfree(de);
out:
- write_unlock(&ls->ls_dirtbl[bucket].lock);
+ spin_unlock(&ls->ls_dirtbl[bucket].lock);
}

void dlm_dir_clear(struct dlm_ls *ls)
@@ -185,14 +185,14 @@ void dlm_dir_clear(struct dlm_ls *ls)
DLM_ASSERT(list_empty(&ls->ls_recover_list), );

for (i = 0; i < ls->ls_dirtbl_size; i++) {
- write_lock(&ls->ls_dirtbl[i].lock);
+ spin_lock(&ls->ls_dirtbl[i].lock);
head = &ls->ls_dirtbl[i].list;
while (!list_empty(head)) {
de = list_entry(head->next, struct dlm_direntry, list);
list_del(&de->list);
put_free_de(ls, de);
}
- write_unlock(&ls->ls_dirtbl[i].lock);
+ spin_unlock(&ls->ls_dirtbl[i].lock);
}
}

@@ -307,17 +307,17 @@ static int get_entry(struct dlm_ls *ls, int nodeid, char *name,

bucket = dir_hash(ls, name, namelen);

- write_lock(&ls->ls_dirtbl[bucket].lock);
+ spin_lock(&ls->ls_dirtbl[bucket].lock);
de = search_bucket(ls, name, namelen, bucket);
if (de) {
*r_nodeid = de->master_nodeid;
- write_unlock(&ls->ls_dirtbl[bucket].lock);
+ spin_unlock(&ls->ls_dirtbl[bucket].lock);
if (*r_nodeid == nodeid)
return -EEXIST;
return 0;
}

- write_unlock(&ls->ls_dirtbl[bucket].lock);
+ spin_unlock(&ls->ls_dirtbl[bucket].lock);

if (namelen > DLM_RESNAME_MAXLEN)
return -EINVAL;
@@ -330,7 +330,7 @@ static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
de->length = namelen;
memcpy(de->name, name, namelen);

- write_lock(&ls->ls_dirtbl[bucket].lock);
+ spin_lock(&ls->ls_dirtbl[bucket].lock);
tmp = search_bucket(ls, name, namelen, bucket);
if (tmp) {
kfree(de);
@@ -339,7 +339,7 @@ static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
list_add_tail(&de->list, &ls->ls_dirtbl[bucket].list);
}
*r_nodeid = de->master_nodeid;
- write_unlock(&ls->ls_dirtbl[bucket].lock);
+ spin_unlock(&ls->ls_dirtbl[bucket].lock);
return 0;
}

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 076e86f..d01ca0a 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -99,7 +99,7 @@ struct dlm_direntry {

struct dlm_dirtable {
struct list_head list;
- rwlock_t lock;
+ spinlock_t lock;
};

struct dlm_rsbtable {
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index aa32e5f..cd8e2df 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -487,7 +487,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
goto out_lkbfree;
for (i = 0; i < size; i++) {
INIT_LIST_HEAD(&ls->ls_dirtbl[i].list);
- rwlock_init(&ls->ls_dirtbl[i].lock);
+ spin_lock_init(&ls->ls_dirtbl[i].lock);
}

INIT_LIST_HEAD(&ls->ls_waiters);
--
1.5.5.6