[lustre-devel] [PATCH 04/20] staging: lustre: convert osc_quota hash to rhashtable
NeilBrown
neilb at suse.com
Wed Apr 11 14:54:48 PDT 2018
As this is indexed by an integer, an extensible array
or extensible bitmap would be better.
If/when xarray lands, we should change to use that.
For now, just a simple conversion to rhashtable.
When removing an entry, we need to hold rcu_read_lock()
across the lookup and remove in case we race with another thread
performing a removal. This means we need to use call_rcu()
to free the quota info so we need an rcu_head in there, which
unfortunately doubles the size of the structure.
Signed-off-by: NeilBrown <neilb at suse.com>
---
drivers/staging/lustre/lustre/include/obd.h | 2
drivers/staging/lustre/lustre/osc/osc_internal.h | 5 -
drivers/staging/lustre/lustre/osc/osc_quota.c | 136 +++++++---------------
3 files changed, 48 insertions(+), 95 deletions(-)
diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h
index 1818fe6a7a2f..682902e744e2 100644
--- a/drivers/staging/lustre/lustre/include/obd.h
+++ b/drivers/staging/lustre/lustre/include/obd.h
@@ -333,7 +333,7 @@ struct client_obd {
void *cl_writeback_work;
void *cl_lru_work;
/* hash tables for osc_quota_info */
- struct cfs_hash *cl_quota_hash[MAXQUOTAS];
+ struct rhashtable cl_quota_hash[MAXQUOTAS];
};
#define obd2cli_tgt(obd) ((char *)(obd)->u.cli.cl_target_uuid.uuid)
diff --git a/drivers/staging/lustre/lustre/osc/osc_internal.h b/drivers/staging/lustre/lustre/osc/osc_internal.h
index be8c7829b3de..fca020568c19 100644
--- a/drivers/staging/lustre/lustre/osc/osc_internal.h
+++ b/drivers/staging/lustre/lustre/osc/osc_internal.h
@@ -188,8 +188,9 @@ extern struct lu_kmem_descr osc_caches[];
extern struct kmem_cache *osc_quota_kmem;
struct osc_quota_info {
/** linkage for quota hash table */
- struct hlist_node oqi_hash;
- u32 oqi_id;
+ struct rhash_head oqi_hash;
+ u32 oqi_id;
+ struct rcu_head rcu;
};
int osc_quota_setup(struct obd_device *obd);
diff --git a/drivers/staging/lustre/lustre/osc/osc_quota.c b/drivers/staging/lustre/lustre/osc/osc_quota.c
index ce1731dc604f..723ec2fb18bf 100644
--- a/drivers/staging/lustre/lustre/osc/osc_quota.c
+++ b/drivers/staging/lustre/lustre/osc/osc_quota.c
@@ -27,6 +27,13 @@
#include <obd_class.h>
#include "osc_internal.h"
+static const struct rhashtable_params quota_hash_params = {
+ .key_len = sizeof(u32),
+ .key_offset = offsetof(struct osc_quota_info, oqi_id),
+ .head_offset = offsetof(struct osc_quota_info, oqi_hash),
+ .automatic_shrinking = true,
+};
+
static inline struct osc_quota_info *osc_oqi_alloc(u32 id)
{
struct osc_quota_info *oqi;
@@ -45,9 +52,10 @@ int osc_quota_chkdq(struct client_obd *cli, const unsigned int qid[])
for (type = 0; type < MAXQUOTAS; type++) {
struct osc_quota_info *oqi;
- oqi = cfs_hash_lookup(cli->cl_quota_hash[type], &qid[type]);
+ oqi = rhashtable_lookup_fast(&cli->cl_quota_hash[type], &qid[type],
+ quota_hash_params);
if (oqi) {
- /* do not try to access oqi here, it could have been
+ /* Must not access oqi here, it could have been
* freed by osc_quota_setdq()
*/
@@ -63,6 +71,14 @@ int osc_quota_chkdq(struct client_obd *cli, const unsigned int qid[])
return QUOTA_OK;
}
+static void osc_quota_free(struct rcu_head *head)
+{
+ struct osc_quota_info *oqi = container_of(head, struct osc_quota_info, rcu);
+
+ kmem_cache_free(osc_quota_kmem, oqi);
+}
+
+
#define MD_QUOTA_FLAG(type) ((type == USRQUOTA) ? OBD_MD_FLUSRQUOTA \
: OBD_MD_FLGRPQUOTA)
#define FL_QUOTA_FLAG(type) ((type == USRQUOTA) ? OBD_FL_NO_USRQUOTA \
@@ -84,11 +100,14 @@ int osc_quota_setdq(struct client_obd *cli, const unsigned int qid[],
continue;
/* lookup the ID in the per-type hash table */
- oqi = cfs_hash_lookup(cli->cl_quota_hash[type], &qid[type]);
+ rcu_read_lock();
+ oqi = rhashtable_lookup_fast(&cli->cl_quota_hash[type], &qid[type],
+ quota_hash_params);
if ((flags & FL_QUOTA_FLAG(type)) != 0) {
/* This ID is getting close to its quota limit, let's
* switch to sync I/O
*/
+ rcu_read_unlock();
if (oqi)
continue;
@@ -98,12 +117,16 @@ int osc_quota_setdq(struct client_obd *cli, const unsigned int qid[],
break;
}
- rc = cfs_hash_add_unique(cli->cl_quota_hash[type],
- &qid[type], &oqi->oqi_hash);
+ rc = rhashtable_lookup_insert_fast(&cli->cl_quota_hash[type],
+ &oqi->oqi_hash, quota_hash_params);
/* race with others? */
- if (rc == -EALREADY) {
- rc = 0;
+ if (rc) {
kmem_cache_free(osc_quota_kmem, oqi);
+ if (rc != -EEXIST) {
+ rc = -ENOMEM;
+ break;
+ }
+ rc = 0;
}
CDEBUG(D_QUOTA, "%s: setdq to insert for %s %d (%d)\n",
@@ -114,14 +137,14 @@ int osc_quota_setdq(struct client_obd *cli, const unsigned int qid[],
/* This ID is now off the hook, let's remove it from
* the hash table
*/
- if (!oqi)
+ if (!oqi) {
+ rcu_read_unlock();
continue;
-
- oqi = cfs_hash_del_key(cli->cl_quota_hash[type],
- &qid[type]);
- if (oqi)
- kmem_cache_free(osc_quota_kmem, oqi);
-
+ }
+ if (rhashtable_remove_fast(&cli->cl_quota_hash[type],
+ &oqi->oqi_hash, quota_hash_params) == 0)
+ call_rcu(&oqi->rcu, osc_quota_free);
+ rcu_read_unlock();
CDEBUG(D_QUOTA, "%s: setdq to remove for %s %d (%p)\n",
cli_name(cli),
type == USRQUOTA ? "user" : "group",
@@ -132,93 +155,21 @@ int osc_quota_setdq(struct client_obd *cli, const unsigned int qid[],
return rc;
}
-/*
- * Hash operations for uid/gid <-> osc_quota_info
- */
-static unsigned int
-oqi_hashfn(struct cfs_hash *hs, const void *key, unsigned int mask)
-{
- return cfs_hash_u32_hash(*((__u32 *)key), mask);
-}
-
-static int
-oqi_keycmp(const void *key, struct hlist_node *hnode)
-{
- struct osc_quota_info *oqi;
- u32 uid;
-
- LASSERT(key);
- uid = *((u32 *)key);
- oqi = hlist_entry(hnode, struct osc_quota_info, oqi_hash);
-
- return uid == oqi->oqi_id;
-}
-
-static void *
-oqi_key(struct hlist_node *hnode)
-{
- struct osc_quota_info *oqi;
-
- oqi = hlist_entry(hnode, struct osc_quota_info, oqi_hash);
- return &oqi->oqi_id;
-}
-
-static void *
-oqi_object(struct hlist_node *hnode)
-{
- return hlist_entry(hnode, struct osc_quota_info, oqi_hash);
-}
-
-static void
-oqi_get(struct cfs_hash *hs, struct hlist_node *hnode)
-{
-}
-
-static void
-oqi_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
-{
-}
-
static void
-oqi_exit(struct cfs_hash *hs, struct hlist_node *hnode)
+oqi_exit(void *vquota, void *data)
{
- struct osc_quota_info *oqi;
-
- oqi = hlist_entry(hnode, struct osc_quota_info, oqi_hash);
+ struct osc_quota_info *oqi = vquota;
- kmem_cache_free(osc_quota_kmem, oqi);
+ osc_quota_free(&oqi->rcu);
}
-#define HASH_QUOTA_BKT_BITS 5
-#define HASH_QUOTA_CUR_BITS 5
-#define HASH_QUOTA_MAX_BITS 15
-
-static struct cfs_hash_ops quota_hash_ops = {
- .hs_hash = oqi_hashfn,
- .hs_keycmp = oqi_keycmp,
- .hs_key = oqi_key,
- .hs_object = oqi_object,
- .hs_get = oqi_get,
- .hs_put_locked = oqi_put_locked,
- .hs_exit = oqi_exit,
-};
-
int osc_quota_setup(struct obd_device *obd)
{
struct client_obd *cli = &obd->u.cli;
int i, type;
for (type = 0; type < MAXQUOTAS; type++) {
- cli->cl_quota_hash[type] = cfs_hash_create("QUOTA_HASH",
- HASH_QUOTA_CUR_BITS,
- HASH_QUOTA_MAX_BITS,
- HASH_QUOTA_BKT_BITS,
- 0,
- CFS_HASH_MIN_THETA,
- CFS_HASH_MAX_THETA,
- "a_hash_ops,
- CFS_HASH_DEFAULT);
- if (!cli->cl_quota_hash[type])
+ if (rhashtable_init(&cli->cl_quota_hash[type], "a_hash_params) != 0)
break;
}
@@ -226,7 +177,7 @@ int osc_quota_setup(struct obd_device *obd)
return 0;
for (i = 0; i < type; i++)
- cfs_hash_putref(cli->cl_quota_hash[i]);
+ rhashtable_destroy(&cli->cl_quota_hash[i]);
return -ENOMEM;
}
@@ -237,7 +188,8 @@ int osc_quota_cleanup(struct obd_device *obd)
int type;
for (type = 0; type < MAXQUOTAS; type++)
- cfs_hash_putref(cli->cl_quota_hash[type]);
+ rhashtable_free_and_destroy(&cli->cl_quota_hash[type],
+ oqi_exit, NULL);
return 0;
}
More information about the lustre-devel
mailing list