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path: root/fs/dlm/lock.c
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Diffstat (limited to 'fs/dlm/lock.c')
-rw-r--r--fs/dlm/lock.c119
1 files changed, 82 insertions, 37 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 784cde417ced..9ebeaa6e6903 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -327,19 +327,68 @@ static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
* Basic operations on rsb's and lkb's
*/
-static struct dlm_rsb *create_rsb(struct dlm_ls *ls, char *name, int len)
+static int pre_rsb_struct(struct dlm_ls *ls)
+{
+ struct dlm_rsb *r1, *r2;
+ int count = 0;
+
+ spin_lock(&ls->ls_new_rsb_spin);
+ if (ls->ls_new_rsb_count > dlm_config.ci_new_rsb_count / 2) {
+ spin_unlock(&ls->ls_new_rsb_spin);
+ return 0;
+ }
+ spin_unlock(&ls->ls_new_rsb_spin);
+
+ r1 = dlm_allocate_rsb(ls);
+ r2 = dlm_allocate_rsb(ls);
+
+ spin_lock(&ls->ls_new_rsb_spin);
+ if (r1) {
+ list_add(&r1->res_hashchain, &ls->ls_new_rsb);
+ ls->ls_new_rsb_count++;
+ }
+ if (r2) {
+ list_add(&r2->res_hashchain, &ls->ls_new_rsb);
+ ls->ls_new_rsb_count++;
+ }
+ count = ls->ls_new_rsb_count;
+ spin_unlock(&ls->ls_new_rsb_spin);
+
+ if (!count)
+ return -ENOMEM;
+ return 0;
+}
+
+/* If ls->ls_new_rsb is empty, return -EAGAIN, so the caller can
+ unlock any spinlocks, go back and call pre_rsb_struct again.
+ Otherwise, take an rsb off the list and return it. */
+
+static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
+ struct dlm_rsb **r_ret)
{
struct dlm_rsb *r;
+ int count;
- r = dlm_allocate_rsb(ls, len);
- if (!r)
- return NULL;
+ spin_lock(&ls->ls_new_rsb_spin);
+ if (list_empty(&ls->ls_new_rsb)) {
+ count = ls->ls_new_rsb_count;
+ spin_unlock(&ls->ls_new_rsb_spin);
+ log_debug(ls, "find_rsb retry %d %d %s",
+ count, dlm_config.ci_new_rsb_count, name);
+ return -EAGAIN;
+ }
+
+ r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain);
+ list_del(&r->res_hashchain);
+ ls->ls_new_rsb_count--;
+ spin_unlock(&ls->ls_new_rsb_spin);
r->res_ls = ls;
r->res_length = len;
memcpy(r->res_name, name, len);
mutex_init(&r->res_mutex);
+ INIT_LIST_HEAD(&r->res_hashchain);
INIT_LIST_HEAD(&r->res_lookup);
INIT_LIST_HEAD(&r->res_grantqueue);
INIT_LIST_HEAD(&r->res_convertqueue);
@@ -347,7 +396,8 @@ static struct dlm_rsb *create_rsb(struct dlm_ls *ls, char *name, int len)
INIT_LIST_HEAD(&r->res_root_list);
INIT_LIST_HEAD(&r->res_recover_list);
- return r;
+ *r_ret = r;
+ return 0;
}
static int search_rsb_list(struct list_head *head, char *name, int len,
@@ -405,16 +455,6 @@ static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
return error;
}
-static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
- unsigned int flags, struct dlm_rsb **r_ret)
-{
- int error;
- spin_lock(&ls->ls_rsbtbl[b].lock);
- error = _search_rsb(ls, name, len, b, flags, r_ret);
- spin_unlock(&ls->ls_rsbtbl[b].lock);
- return error;
-}
-
/*
* Find rsb in rsbtbl and potentially create/add one
*
@@ -432,35 +472,48 @@ static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
unsigned int flags, struct dlm_rsb **r_ret)
{
- struct dlm_rsb *r = NULL, *tmp;
+ struct dlm_rsb *r = NULL;
uint32_t hash, bucket;
- int error = -EINVAL;
+ int error;
- if (namelen > DLM_RESNAME_MAXLEN)
+ if (namelen > DLM_RESNAME_MAXLEN) {
+ error = -EINVAL;
goto out;
+ }
if (dlm_no_directory(ls))
flags |= R_CREATE;
- error = 0;
hash = jhash(name, namelen, 0);
bucket = hash & (ls->ls_rsbtbl_size - 1);
- error = search_rsb(ls, name, namelen, bucket, flags, &r);
+ retry:
+ if (flags & R_CREATE) {
+ error = pre_rsb_struct(ls);
+ if (error < 0)
+ goto out;
+ }
+
+ spin_lock(&ls->ls_rsbtbl[bucket].lock);
+
+ error = _search_rsb(ls, name, namelen, bucket, flags, &r);
if (!error)
- goto out;
+ goto out_unlock;
if (error == -EBADR && !(flags & R_CREATE))
- goto out;
+ goto out_unlock;
/* the rsb was found but wasn't a master copy */
if (error == -ENOTBLK)
- goto out;
+ goto out_unlock;
- error = -ENOMEM;
- r = create_rsb(ls, name, namelen);
- if (!r)
- goto out;
+ error = get_rsb_struct(ls, name, namelen, &r);
+ if (error == -EAGAIN) {
+ spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+ goto retry;
+ }
+ if (error)
+ goto out_unlock;
r->res_hash = hash;
r->res_bucket = bucket;
@@ -474,18 +527,10 @@ static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
nodeid = 0;
r->res_nodeid = nodeid;
}
-
- spin_lock(&ls->ls_rsbtbl[bucket].lock);
- error = _search_rsb(ls, name, namelen, bucket, 0, &tmp);
- if (!error) {
- spin_unlock(&ls->ls_rsbtbl[bucket].lock);
- dlm_free_rsb(r);
- r = tmp;
- goto out;
- }
list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
- spin_unlock(&ls->ls_rsbtbl[bucket].lock);
error = 0;
+ out_unlock:
+ spin_unlock(&ls->ls_rsbtbl[bucket].lock);
out:
*r_ret = r;
return error;