[lustre-devel] [PATCH 03/20] staging: lustre: convert obd uuid hash to rhashtable
NeilBrown
neilb at suse.com
Wed Apr 11 14:54:48 PDT 2018
The rhashtable data type is a perfect fit for the
export uuid hash table, so use that instead of
cfs_hash (which will eventually be removed).
As rhashtable supports lookups and insertions in atomic
context, there is no need to drop a spinlock while
inserting a new entry, which simplifies code quite a bit.
As there are no simple lookups on this hash table (only
insertions which might fail and take a spinlock), there is
no need to use rcu to free the exports.
Signed-off-by: NeilBrown <neilb at suse.com>
---
.../staging/lustre/lustre/include/lustre_export.h | 2
drivers/staging/lustre/lustre/include/obd.h | 5 -
.../staging/lustre/lustre/include/obd_support.h | 3
drivers/staging/lustre/lustre/obdclass/genops.c | 34 +---
.../staging/lustre/lustre/obdclass/obd_config.c | 161 +++++++++-----------
5 files changed, 80 insertions(+), 125 deletions(-)
diff --git a/drivers/staging/lustre/lustre/include/lustre_export.h b/drivers/staging/lustre/lustre/include/lustre_export.h
index 19ce13bc8ee6..79ad5aae86b9 100644
--- a/drivers/staging/lustre/lustre/include/lustre_export.h
+++ b/drivers/staging/lustre/lustre/include/lustre_export.h
@@ -89,7 +89,7 @@ struct obd_export {
struct list_head exp_obd_chain;
/** work_struct for destruction of export */
struct work_struct exp_zombie_work;
- struct hlist_node exp_uuid_hash; /** uuid-export hash*/
+ struct rhash_head exp_uuid_hash; /** uuid-export hash*/
/** Obd device of this export */
struct obd_device *exp_obd;
/**
diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h
index ad265db48b76..1818fe6a7a2f 100644
--- a/drivers/staging/lustre/lustre/include/obd.h
+++ b/drivers/staging/lustre/lustre/include/obd.h
@@ -558,7 +558,7 @@ struct obd_device {
*/
unsigned long obd_recovery_expired:1;
/* uuid-export hash body */
- struct cfs_hash *obd_uuid_hash;
+ struct rhashtable obd_uuid_hash;
wait_queue_head_t obd_refcount_waitq;
struct list_head obd_exports;
struct list_head obd_unlinked_exports;
@@ -622,6 +622,9 @@ struct obd_device {
struct completion obd_kobj_unregister;
};
+int obd_uuid_add(struct obd_device *obd, struct obd_export *export);
+void obd_uuid_del(struct obd_device *obd, struct obd_export *export);
+
/* get/set_info keys */
#define KEY_ASYNC "async"
#define KEY_CHANGELOG_CLEAR "changelog_clear"
diff --git a/drivers/staging/lustre/lustre/include/obd_support.h b/drivers/staging/lustre/lustre/include/obd_support.h
index 730a6ee71565..a4c7a2ee9738 100644
--- a/drivers/staging/lustre/lustre/include/obd_support.h
+++ b/drivers/staging/lustre/lustre/include/obd_support.h
@@ -61,9 +61,6 @@ extern atomic_long_t obd_dirty_transit_pages;
extern char obd_jobid_var[];
/* Some hash init argument constants */
-#define HASH_UUID_BKT_BITS 5
-#define HASH_UUID_CUR_BITS 7
-#define HASH_UUID_MAX_BITS 12
/* Timeout definitions */
#define OBD_TIMEOUT_DEFAULT 100
/* Time to wait for all clients to reconnect during recovery (hard limit) */
diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c
index 86e22472719a..af233b868742 100644
--- a/drivers/staging/lustre/lustre/obdclass/genops.c
+++ b/drivers/staging/lustre/lustre/obdclass/genops.c
@@ -713,7 +713,6 @@ struct obd_export *class_new_export(struct obd_device *obd,
struct obd_uuid *cluuid)
{
struct obd_export *export;
- struct cfs_hash *hash = NULL;
int rc = 0;
export = kzalloc(sizeof(*export), GFP_NOFS);
@@ -740,7 +739,6 @@ struct obd_export *class_new_export(struct obd_device *obd,
class_handle_hash(&export->exp_handle, &export_handle_ops);
spin_lock_init(&export->exp_lock);
spin_lock_init(&export->exp_rpc_lock);
- INIT_HLIST_NODE(&export->exp_uuid_hash);
spin_lock_init(&export->exp_bl_list_lock);
INIT_LIST_HEAD(&export->exp_bl_list);
INIT_WORK(&export->exp_zombie_work, obd_zombie_exp_cull);
@@ -757,44 +755,24 @@ struct obd_export *class_new_export(struct obd_device *obd,
goto exit_unlock;
}
- hash = cfs_hash_getref(obd->obd_uuid_hash);
- if (!hash) {
- rc = -ENODEV;
- goto exit_unlock;
- }
- spin_unlock(&obd->obd_dev_lock);
-
if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
- rc = cfs_hash_add_unique(hash, cluuid, &export->exp_uuid_hash);
- if (rc != 0) {
+ rc = obd_uuid_add(obd, export);
+ if (rc) {
LCONSOLE_WARN("%s: denying duplicate export for %s, %d\n",
obd->obd_name, cluuid->uuid, rc);
- rc = -EALREADY;
- goto exit_err;
+ goto exit_unlock;
}
}
- spin_lock(&obd->obd_dev_lock);
- if (obd->obd_stopping) {
- cfs_hash_del(hash, cluuid, &export->exp_uuid_hash);
- rc = -ENODEV;
- goto exit_unlock;
- }
-
class_incref(obd, "export", export);
list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
export->exp_obd->obd_num_exports++;
spin_unlock(&obd->obd_dev_lock);
- cfs_hash_putref(hash);
return export;
exit_unlock:
spin_unlock(&obd->obd_dev_lock);
-exit_err:
- if (hash)
- cfs_hash_putref(hash);
class_handle_unhash(&export->exp_handle);
- LASSERT(hlist_unhashed(&export->exp_uuid_hash));
obd_destroy_export(export);
kfree(export);
return ERR_PTR(rc);
@@ -807,10 +785,8 @@ void class_unlink_export(struct obd_export *exp)
spin_lock(&exp->exp_obd->obd_dev_lock);
/* delete an uuid-export hashitem from hashtables */
- if (!hlist_unhashed(&exp->exp_uuid_hash))
- cfs_hash_del(exp->exp_obd->obd_uuid_hash,
- &exp->exp_client_uuid,
- &exp->exp_uuid_hash);
+ if (exp != exp->exp_obd->obd_self_export)
+ obd_uuid_del(exp->exp_obd, exp);
list_move(&exp->exp_obd_chain, &exp->exp_obd->obd_unlinked_exports);
exp->exp_obd->obd_num_exports--;
diff --git a/drivers/staging/lustre/lustre/obdclass/obd_config.c b/drivers/staging/lustre/lustre/obdclass/obd_config.c
index eab03766236f..ffc1814398a5 100644
--- a/drivers/staging/lustre/lustre/obdclass/obd_config.c
+++ b/drivers/staging/lustre/lustre/obdclass/obd_config.c
@@ -48,7 +48,69 @@
#include "llog_internal.h"
-static struct cfs_hash_ops uuid_hash_ops;
+/*
+ * uuid<->export lustre hash operations
+ */
+/*
+ * NOTE: It is impossible to find an export that is in failed
+ * state with this function
+ */
+static int
+uuid_keycmp(struct rhashtable_compare_arg *arg, const void *obj)
+{
+ const struct obd_uuid *uuid = arg->key;
+ const struct obd_export *exp = obj;
+
+ if (obd_uuid_equals(uuid, &exp->exp_client_uuid) &&
+ !exp->exp_failed)
+ return 0;
+ return -ESRCH;
+}
+
+static void
+uuid_export_exit(void *vexport, void *data)
+{
+ struct obd_export *exp = vexport;
+
+ class_export_put(exp);
+}
+
+static const struct rhashtable_params uuid_hash_params = {
+ .key_len = sizeof(struct obd_uuid),
+ .key_offset = offsetof(struct obd_export, exp_client_uuid),
+ .head_offset = offsetof(struct obd_export, exp_uuid_hash),
+ .obj_cmpfn = uuid_keycmp,
+ .automatic_shrinking = true,
+};
+
+int obd_uuid_add(struct obd_device *obd, struct obd_export *export)
+{
+ int rc;
+
+ rc = rhashtable_lookup_insert_fast(&obd->obd_uuid_hash,
+ &export->exp_uuid_hash,
+ uuid_hash_params);
+ if (rc == 0)
+ class_export_get(export);
+ else if (rc == -EEXIST)
+ rc = -EALREADY;
+ else
+ /* map obscure error codes to -ENOMEM */
+ rc = -ENOMEM;
+ return rc;
+}
+
+void obd_uuid_del(struct obd_device *obd, struct obd_export *export)
+{
+ int rc;
+
+ rc = rhashtable_remove_fast(&obd->obd_uuid_hash,
+ &export->exp_uuid_hash,
+ uuid_hash_params);
+
+ if (rc == 0)
+ class_export_put(export);
+}
/*********** string parsing utils *********/
@@ -347,26 +409,18 @@ static int class_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
* other fns check that status, and we're not actually set up yet.
*/
obd->obd_starting = 1;
- obd->obd_uuid_hash = NULL;
spin_unlock(&obd->obd_dev_lock);
/* create an uuid-export lustre hash */
- obd->obd_uuid_hash = cfs_hash_create("UUID_HASH",
- HASH_UUID_CUR_BITS,
- HASH_UUID_MAX_BITS,
- HASH_UUID_BKT_BITS, 0,
- CFS_HASH_MIN_THETA,
- CFS_HASH_MAX_THETA,
- &uuid_hash_ops, CFS_HASH_DEFAULT);
- if (!obd->obd_uuid_hash) {
- err = -ENOMEM;
+ err = rhashtable_init(&obd->obd_uuid_hash, &uuid_hash_params);
+
+ if (err)
goto err_hash;
- }
exp = class_new_export(obd, &obd->obd_uuid);
if (IS_ERR(exp)) {
err = PTR_ERR(exp);
- goto err_hash;
+ goto err_new;
}
obd->obd_self_export = exp;
@@ -392,11 +446,9 @@ static int class_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
class_unlink_export(obd->obd_self_export);
obd->obd_self_export = NULL;
}
+err_new:
+ rhashtable_destroy(&obd->obd_uuid_hash);
err_hash:
- if (obd->obd_uuid_hash) {
- cfs_hash_putref(obd->obd_uuid_hash);
- obd->obd_uuid_hash = NULL;
- }
obd->obd_starting = 0;
CERROR("setup %s failed (%d)\n", obd->obd_name, err);
return err;
@@ -490,10 +542,7 @@ static int class_cleanup(struct obd_device *obd, struct lustre_cfg *lcfg)
obd->obd_name, err);
/* destroy an uuid-export hash body */
- if (obd->obd_uuid_hash) {
- cfs_hash_putref(obd->obd_uuid_hash);
- obd->obd_uuid_hash = NULL;
- }
+ rhashtable_free_and_destroy(&obd->obd_uuid_hash, uuid_export_exit, NULL);
class_decref(obd, "setup", obd);
obd->obd_set_up = 0;
@@ -1487,73 +1536,3 @@ int class_manual_cleanup(struct obd_device *obd)
return rc;
}
EXPORT_SYMBOL(class_manual_cleanup);
-
-/*
- * uuid<->export lustre hash operations
- */
-
-static unsigned int
-uuid_hash(struct cfs_hash *hs, const void *key, unsigned int mask)
-{
- return cfs_hash_djb2_hash(((struct obd_uuid *)key)->uuid,
- sizeof(((struct obd_uuid *)key)->uuid), mask);
-}
-
-static void *
-uuid_key(struct hlist_node *hnode)
-{
- struct obd_export *exp;
-
- exp = hlist_entry(hnode, struct obd_export, exp_uuid_hash);
-
- return &exp->exp_client_uuid;
-}
-
-/*
- * NOTE: It is impossible to find an export that is in failed
- * state with this function
- */
-static int
-uuid_keycmp(const void *key, struct hlist_node *hnode)
-{
- struct obd_export *exp;
-
- LASSERT(key);
- exp = hlist_entry(hnode, struct obd_export, exp_uuid_hash);
-
- return obd_uuid_equals(key, &exp->exp_client_uuid) &&
- !exp->exp_failed;
-}
-
-static void *
-uuid_export_object(struct hlist_node *hnode)
-{
- return hlist_entry(hnode, struct obd_export, exp_uuid_hash);
-}
-
-static void
-uuid_export_get(struct cfs_hash *hs, struct hlist_node *hnode)
-{
- struct obd_export *exp;
-
- exp = hlist_entry(hnode, struct obd_export, exp_uuid_hash);
- class_export_get(exp);
-}
-
-static void
-uuid_export_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
-{
- struct obd_export *exp;
-
- exp = hlist_entry(hnode, struct obd_export, exp_uuid_hash);
- class_export_put(exp);
-}
-
-static struct cfs_hash_ops uuid_hash_ops = {
- .hs_hash = uuid_hash,
- .hs_key = uuid_key,
- .hs_keycmp = uuid_keycmp,
- .hs_object = uuid_export_object,
- .hs_get = uuid_export_get,
- .hs_put_locked = uuid_export_put_locked,
-};
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