From 27d00e6ca41526f8c771878deaf4bd5a637a8358 Mon Sep 17 00:00:00 2001
From: nathan <nathan>
Date: Fri, 5 Dec 2008 23:54:38 +0000
Subject: [PATCH] b=17181 i=johann i=nathan add pool refcount replace rwlock
with semaphore
---
lustre/include/obd.h | 5 +-
lustre/lov/lov_obd.c | 6 +-
lustre/lov/lov_pack.c | 7 +-
lustre/lov/lov_pool.c | 162 ++++++++++++++++++++++++++++++------------
lustre/lov/lov_qos.c | 29 +++++---
5 files changed, 147 insertions(+), 62 deletions(-)
diff --git a/lustre/include/obd.h b/lustre/include/obd.h
index 3aa9f0ee8e..cf5979c732 100644
--- a/lustre/include/obd.h
+++ b/lustre/include/obd.h
@@ -622,7 +622,7 @@ struct ost_pool {
lov_obd->lov_tgts */
unsigned int op_count; /* number of OSTs in the array */
unsigned int op_size; /* allocated size of lp_array */
- rwlock_t op_rwlock; /* to protect lov_pool use */
+ struct rw_semaphore op_rw_sem; /* to protect ost_pool use */
};
/* Round-robin allocator data */
@@ -662,12 +662,13 @@ struct lov_tgt_desc {
#define pool_tgt_size(_p) _p->pool_obds.op_size
#define pool_tgt_count(_p) _p->pool_obds.op_count
#define pool_tgt_array(_p) _p->pool_obds.op_array
-#define pool_tgt_rwlock(_p) _p->pool_obds.op_rwlock
+#define pool_tgt_rw_sem(_p) _p->pool_obds.op_rw_sem
#define pool_tgt(_p, _i) _p->pool_lov->lov_tgts[_p->pool_obds.op_array[_i]]
struct pool_desc {
char pool_name[LOV_MAXPOOLNAME + 1]; /* name of pool */
struct ost_pool pool_obds; /* pool members */
+ atomic_t pool_refcount; /* pool ref. counter */
struct lov_qos_rr pool_rr; /* round robin qos */
struct hlist_node pool_hash; /* access by poolname */
struct list_head pool_list; /* serial access */
diff --git a/lustre/lov/lov_obd.c b/lustre/lov/lov_obd.c
index eb32c62eae..cc2097e244 100644
--- a/lustre/lov/lov_obd.c
+++ b/lustre/lov/lov_obd.c
@@ -879,10 +879,8 @@ static int lov_cleanup(struct obd_device *obd)
list_for_each_safe(pos, tmp, &lov->lov_pool_list) {
pool = list_entry(pos, struct pool_desc, pool_list);
- list_del(&pool->pool_list);
- lov_ost_pool_free(&(pool->pool_rr.lqr_pool));
- lov_ost_pool_free(&(pool->pool_obds));
- OBD_FREE_PTR(pool);
+ /* free pool structs */
+ lov_pool_del(obd, pool->pool_name);
}
lov_ost_pool_free(&(lov->lov_qos.lq_rr.lqr_pool));
lov_ost_pool_free(&lov->lov_packed);
diff --git a/lustre/lov/lov_pack.c b/lustre/lov/lov_pack.c
index d992e54893..12c2d284c2 100644
--- a/lustre/lov/lov_pack.c
+++ b/lustre/lov/lov_pack.c
@@ -483,12 +483,17 @@ static int __lov_setstripe(struct obd_export *exp, struct lov_stripe_md **lsmp,
(typeof(lumv3.lmm_stripe_offset))(-1)) {
rc = lov_check_index_in_pool(lumv3.lmm_stripe_offset,
pool);
- if (rc < 0)
+ if (rc < 0) {
+ lh_put(lov->lov_pools_hash_body,
+ &pool->pool_hash);
RETURN(-EINVAL);
+ }
}
if (stripe_count > pool_tgt_count(pool))
stripe_count = pool_tgt_count(pool);
+
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
}
if ((__u64)lumv1->lmm_stripe_size * stripe_count > ~0UL) {
diff --git a/lustre/lov/lov_pool.c b/lustre/lov/lov_pool.c
index f63fac745b..1836691885 100644
--- a/lustre/lov/lov_pool.c
+++ b/lustre/lov/lov_pool.c
@@ -51,6 +51,19 @@
#include <obd.h>
#include "lov_internal.h"
+static void lov_pool_getref(struct pool_desc *pool) {
+ atomic_inc(&pool->pool_refcount);
+}
+
+static void lov_pool_putref(struct pool_desc *pool) {
+ if (atomic_dec_and_test(&pool->pool_refcount)) {
+ lov_ost_pool_free(&(pool->pool_rr.lqr_pool));
+ lov_ost_pool_free(&(pool->pool_obds));
+ OBD_FREE_PTR(pool);
+ }
+}
+
+
/*
* hash function using a Rotating Hash algorithm
* Knuth, D. The Art of Computer Programming,
@@ -99,6 +112,7 @@ static void *pool_hashrefcount_get(struct hlist_node *hnode)
struct pool_desc *pool;
pool = hlist_entry(hnode, struct pool_desc, pool_hash);
+ lov_pool_getref(pool);
return (pool);
}
@@ -107,6 +121,7 @@ static void *pool_hashrefcount_put(struct hlist_node *hnode)
struct pool_desc *pool;
pool = hlist_entry(hnode, struct pool_desc, pool_hash);
+ lov_pool_putref(pool);
return (pool);
}
@@ -149,14 +164,14 @@ static void *pool_proc_next(struct seq_file *s, void *v, loff_t *pos)
/* iterate to find a non empty entry */
prev_idx = iter->idx;
- read_lock(&pool_tgt_rwlock(iter->pool));
+ down_read(&pool_tgt_rw_sem(iter->pool));
iter->idx++;
if (iter->idx == pool_tgt_count(iter->pool)) {
iter->idx = prev_idx; /* we stay on the last entry */
- read_unlock(&pool_tgt_rwlock(iter->pool));
+ up_read(&pool_tgt_rw_sem(iter->pool));
return NULL;
}
- read_unlock(&pool_tgt_rwlock(iter->pool));
+ up_read(&pool_tgt_rw_sem(iter->pool));
(*pos)++;
/* return != NULL to continue */
return iter;
@@ -167,11 +182,16 @@ static void *pool_proc_start(struct seq_file *s, loff_t *pos)
struct pool_desc *pool = (struct pool_desc *)s->private;
struct pool_iterator *iter;
+ lov_pool_getref(pool);
if ((pool_tgt_count(pool) == 0) ||
- (*pos >= pool_tgt_count(pool)))
+ (*pos >= pool_tgt_count(pool))) {
+ /* iter is not created, so stop() has no way to
+ * find pool to dec ref */
+ lov_pool_putref(pool);
return NULL;
+ }
- OBD_ALLOC(iter, sizeof(struct pool_iterator));
+ OBD_ALLOC_PTR(iter);
if (!iter)
return ERR_PTR(-ENOMEM);
iter->magic = POOL_IT_MAGIC;
@@ -206,7 +226,8 @@ static void pool_proc_stop(struct seq_file *s, void *v)
/* we restore s->private so next call to pool_proc_start()
* will work */
s->private = iter->pool;
- OBD_FREE(iter, sizeof(struct pool_iterator));
+ lov_pool_putref(iter->pool);
+ OBD_FREE_PTR(iter);
}
return;
}
@@ -220,9 +241,9 @@ static int pool_proc_show(struct seq_file *s, void *v)
LASSERT(iter->pool != NULL);
LASSERT(iter->idx <= pool_tgt_count(iter->pool));
- read_lock(&pool_tgt_rwlock(iter->pool));
+ down_read(&pool_tgt_rw_sem(iter->pool));
tgt = pool_tgt(iter->pool, iter->idx);
- read_unlock(&pool_tgt_rwlock(iter->pool));
+ up_read(&pool_tgt_rw_sem(iter->pool));
if (tgt)
seq_printf(s, "%s\n", obd_uuid2str(&(tgt->ltd_uuid)));
@@ -260,9 +281,12 @@ void lov_dump_pool(int level, struct pool_desc *pool)
{
int i;
+ lov_pool_getref(pool);
+
CDEBUG(level, "pool "LOV_POOLNAMEF" has %d members\n",
pool->pool_name, pool->pool_obds.op_count);
- read_lock(&pool_tgt_rwlock(pool));
+ down_read(&pool_tgt_rw_sem(pool));
+
for (i = 0; i < pool_tgt_count(pool) ; i++) {
if (!pool_tgt(pool, i) || !(pool_tgt(pool, i))->ltd_exp)
continue;
@@ -270,7 +294,9 @@ void lov_dump_pool(int level, struct pool_desc *pool)
pool->pool_name, i,
obd_uuid2str(&((pool_tgt(pool, i))->ltd_uuid)));
}
- read_unlock(&pool_tgt_rwlock(pool));
+
+ up_read(&pool_tgt_rw_sem(pool));
+ lov_pool_putref(pool);
}
#define LOV_POOL_INIT_COUNT 2
@@ -280,7 +306,7 @@ int lov_ost_pool_init(struct ost_pool *op, unsigned int count)
count = LOV_POOL_INIT_COUNT;
op->op_array = NULL;
op->op_count = 0;
- rwlock_init(&op->op_rwlock);
+ init_rwsem(&op->op_rw_sem);
op->op_size = count;
OBD_ALLOC(op->op_array, op->op_size * sizeof(op->op_array[0]));
if (op->op_array == NULL) {
@@ -319,7 +345,7 @@ int lov_ost_pool_add(struct ost_pool *op, __u32 idx, unsigned int max_count)
int rc = 0, i;
ENTRY;
- write_lock(&op->op_rwlock);
+ down_write(&op->op_rw_sem);
rc = lov_ost_pool_extend(op, max_count);
if (rc)
@@ -334,7 +360,7 @@ int lov_ost_pool_add(struct ost_pool *op, __u32 idx, unsigned int max_count)
op->op_array[op->op_count] = idx;
op->op_count++;
out:
- write_unlock(&op->op_rwlock);
+ up_write(&op->op_rw_sem);
return rc;
}
@@ -342,17 +368,19 @@ int lov_ost_pool_remove(struct ost_pool *op, __u32 idx)
{
int i;
- write_lock(&op->op_rwlock);
+ down_write(&op->op_rw_sem);
+
for (i = 0; i < op->op_count; i++) {
if (op->op_array[i] == idx) {
memmove(&op->op_array[i], &op->op_array[i + 1],
(op->op_count - i - 1) * sizeof(op->op_array[0]));
op->op_count--;
- write_unlock(&op->op_rwlock);
+ up_write(&op->op_rw_sem);
return 0;
}
}
- write_unlock(&op->op_rwlock);
+
+ up_write(&op->op_rw_sem);
return -EINVAL;
}
@@ -361,12 +389,14 @@ int lov_ost_pool_free(struct ost_pool *op)
if (op->op_size == 0)
return 0;
- write_lock(&op->op_rwlock);
+ down_write(&op->op_rw_sem);
+
OBD_FREE(op->op_array, op->op_size * sizeof(op->op_array[0]));
op->op_array = NULL;
op->op_count = 0;
op->op_size = 0;
- write_unlock(&op->op_rwlock);
+
+ up_write(&op->op_rw_sem);
return 0;
}
@@ -376,19 +406,24 @@ int lov_pool_new(struct obd_device *obd, char *poolname)
struct lov_obd *lov;
struct pool_desc *new_pool;
int rc;
+ ENTRY;
lov = &(obd->u.lov);
if (strlen(poolname) > LOV_MAXPOOLNAME)
- return -ENAMETOOLONG;
+ RETURN(-ENAMETOOLONG);
OBD_ALLOC_PTR(new_pool);
if (new_pool == NULL)
- return -ENOMEM;
+ RETURN(-ENOMEM);
strncpy(new_pool->pool_name, poolname, LOV_MAXPOOLNAME);
new_pool->pool_name[LOV_MAXPOOLNAME] = '\0';
new_pool->pool_lov = lov;
+ /* ref count init to 1 because when created a pool is always used
+ * up to deletion
+ */
+ atomic_set(&new_pool->pool_refcount, 1);
rc = lov_ost_pool_init(&new_pool->pool_obds, 0);
if (rc)
GOTO(out_err, rc);
@@ -412,6 +447,7 @@ int lov_pool_new(struct obd_device *obd, char *poolname)
spin_lock(&obd->obd_dev_lock);
list_add_tail(&new_pool->pool_list, &lov->lov_pool_list);
lov->lov_pool_count++;
+
spin_unlock(&obd->obd_dev_lock);
CDEBUG(D_CONFIG, LOV_POOLNAMEF" is pool #%d\n",
@@ -419,6 +455,8 @@ int lov_pool_new(struct obd_device *obd, char *poolname)
#ifdef LPROCFS
/* ifdef needed for liblustre */
+ /* get ref for /proc file */
+ lov_pool_getref(new_pool);
new_pool->pool_proc_entry = lprocfs_add_simple(lov->lov_pool_proc_entry,
poolname, NULL, NULL,
new_pool,
@@ -428,9 +466,10 @@ int lov_pool_new(struct obd_device *obd, char *poolname)
if (IS_ERR(new_pool->pool_proc_entry)) {
CWARN("Cannot add proc pool entry "LOV_POOLNAMEF"\n", poolname);
new_pool->pool_proc_entry = NULL;
+ lov_pool_putref(new_pool);
}
- return 0;
+ RETURN(0);
out_err:
OBD_FREE_PTR(new_pool);
@@ -441,33 +480,40 @@ int lov_pool_del(struct obd_device *obd, char *poolname)
{
struct lov_obd *lov;
struct pool_desc *pool;
+ ENTRY;
lov = &(obd->u.lov);
spin_lock(&obd->obd_dev_lock);
- pool = lustre_hash_lookup(lov->lov_pools_hash_body,
- poolname);
+
+ pool = lustre_hash_lookup(lov->lov_pools_hash_body, poolname);
if (pool == NULL) {
spin_unlock(&obd->obd_dev_lock);
- return -ENOENT;
+ RETURN(-ENOENT);
}
#ifdef LPROCFS
- if (pool->pool_proc_entry != NULL)
+ if (pool->pool_proc_entry != NULL) {
remove_proc_entry(pool->pool_proc_entry->name,
pool->pool_proc_entry->parent);
+ /* remove ref for /proc file */
+ lov_pool_putref(pool);
+ }
#endif
lustre_hash_del_key(lov->lov_pools_hash_body, poolname);
+ list_del_init(&pool->pool_list);
lov->lov_pool_count--;
-
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
spin_unlock(&obd->obd_dev_lock);
- /* pool struct is not freed because it may be used by
- * some open in /proc. The struct is freed at lov_cleanup()
- */
- return 0;
+ /* remove ref got when pool was created in memory
+ * pool will be freed when refount will reach 0
+ */
+ lov_pool_putref(pool);
+
+ RETURN(0);
}
@@ -478,12 +524,13 @@ int lov_pool_add(struct obd_device *obd, char *poolname, char *ostname)
struct pool_desc *pool;
unsigned int i, lov_idx;
int rc;
+ ENTRY;
lov = &(obd->u.lov);
pool = lustre_hash_lookup(lov->lov_pools_hash_body, poolname);
if (pool == NULL)
- return -ENOENT;
+ RETURN(-ENOENT);
obd_str2uuid(&ost_uuid, ostname);
@@ -500,7 +547,7 @@ int lov_pool_add(struct obd_device *obd, char *poolname, char *ostname)
/* test if ost found in lov */
if (i == lov->desc.ld_tgt_count) {
mutex_up(&lov->lov_lock);
- return -EINVAL;
+ GOTO(out, rc = -EINVAL);
}
mutex_up(&lov->lov_lock);
@@ -508,13 +555,17 @@ int lov_pool_add(struct obd_device *obd, char *poolname, char *ostname)
rc = lov_ost_pool_add(&pool->pool_obds, lov_idx, lov->lov_tgt_size);
if (rc)
- return rc;
+ GOTO(out, rc);
pool->pool_rr.lqr_dirty = 1;
CDEBUG(D_CONFIG, "Added %s to "LOV_POOLNAMEF" as member %d\n",
ostname, poolname, pool_tgt_count(pool));
- return 0;
+
+ EXIT;
+out:
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
+ return rc;
}
int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
@@ -523,6 +574,8 @@ int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
struct lov_obd *lov;
struct pool_desc *pool;
unsigned int i, lov_idx;
+ int rc = 0;
+ ENTRY;
lov = &(obd->u.lov);
@@ -530,7 +583,7 @@ int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
pool = lustre_hash_lookup(lov->lov_pools_hash_body, poolname);
if (pool == NULL) {
spin_unlock(&obd->obd_dev_lock);
- return -ENOENT;
+ RETURN(-ENOENT);
}
obd_str2uuid(&ost_uuid, ostname);
@@ -547,7 +600,7 @@ int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
/* test if ost found in lov */
if (i == lov->desc.ld_tgt_count) {
spin_unlock(&obd->obd_dev_lock);
- return -EINVAL;
+ GOTO(out, rc = -EINVAL);
}
spin_unlock(&obd->obd_dev_lock);
@@ -558,24 +611,39 @@ int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
pool->pool_rr.lqr_dirty = 1;
- CDEBUG(D_CONFIG, "%s removed from "LOV_POOLNAMEF"\n", ostname, poolname);
+ CDEBUG(D_CONFIG, "%s removed from "LOV_POOLNAMEF"\n", ostname,
+ poolname);
- return 0;
+ EXIT;
+out:
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
+ return rc;
}
int lov_check_index_in_pool(__u32 idx, struct pool_desc *pool)
{
- int i;
+ int i, rc;
+ ENTRY;
+
+ /* caller may no have a ref on pool if it got the pool
+ * without calling lov_find_pool() (e.g. go through the lov pool
+ * list)
+ */
+ lov_pool_getref(pool);
+
+ down_read(&pool_tgt_rw_sem(pool));
- read_lock(&pool_tgt_rwlock(pool));
for (i = 0; i < pool_tgt_count(pool); i++) {
- if (pool_tgt_array(pool)[i] == idx) {
- read_unlock(&pool_tgt_rwlock(pool));
- return 0;
- }
+ if (pool_tgt_array(pool)[i] == idx)
+ GOTO(out, rc = 0);
}
- read_unlock(&pool_tgt_rwlock(pool));
- return -ENOENT;
+ rc = -ENOENT;
+ EXIT;
+out:
+ up_read(&pool_tgt_rw_sem(pool));
+
+ lov_pool_putref(pool);
+ return rc;
}
struct pool_desc *lov_find_pool(struct lov_obd *lov, char *poolname)
@@ -591,6 +659,8 @@ struct pool_desc *lov_find_pool(struct lov_obd *lov, char *poolname)
if ((pool != NULL) && (pool_tgt_count(pool) == 0)) {
CWARN("Request for an empty pool ("LOV_POOLNAMEF")\n",
poolname);
+ /* pool is ignored, so we remove ref on it */
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
pool = NULL;
}
}
diff --git a/lustre/lov/lov_qos.c b/lustre/lov/lov_qos.c
index 5ad5848a24..45245ed5fa 100644
--- a/lustre/lov/lov_qos.c
+++ b/lustre/lov/lov_qos.c
@@ -560,7 +560,7 @@ static int alloc_rr(struct lov_obd *lov, int *idx_arr, int *stripe_cnt,
osts = &(lov->lov_packed);
lqr = &(lov->lov_qos.lq_rr);
} else {
- read_lock(&pool_tgt_rwlock(pool));
+ down_read(&pool_tgt_rw_sem(pool));
osts = &(pool->pool_obds);
lqr = &(pool->pool_rr);
}
@@ -637,8 +637,12 @@ repeat_find:
*stripe_cnt = idx_pos - idx_arr;
out:
- if (pool != NULL)
- read_unlock(&pool_tgt_rwlock(pool));
+ if (pool != NULL) {
+ up_read(&pool_tgt_rw_sem(pool));
+ /* put back ref got by lov_find_pool() */
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
+ }
+
RETURN(rc);
}
@@ -657,7 +661,7 @@ static int alloc_specific(struct lov_obd *lov, struct lov_stripe_md *lsm,
if (pool == NULL) {
osts = &(lov->lov_packed);
} else {
- read_lock(&pool_tgt_rwlock(pool));
+ down_read(&pool_tgt_rw_sem(pool));
osts = &(pool->pool_obds);
}
@@ -725,8 +729,12 @@ repeat_find:
lsm->lsm_stripe_count);
rc = -EFBIG;
out:
- if (pool != NULL)
- read_unlock(&pool_tgt_rwlock(pool));
+ if (pool != NULL) {
+ up_read(&pool_tgt_rw_sem(pool));
+ /* put back ref got by lov_find_pool() */
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
+ }
+
RETURN(rc);
}
@@ -756,7 +764,7 @@ static int alloc_qos(struct obd_export *exp, int *idx_arr, int *stripe_cnt,
osts = &(lov->lov_packed);
lqr = &(lov->lov_qos.lq_rr);
} else {
- read_lock(&pool_tgt_rwlock(pool));
+ down_read(&pool_tgt_rw_sem(pool));
osts = &(pool->pool_obds);
lqr = &(pool->pool_rr);
}
@@ -916,8 +924,11 @@ out:
up_write(&lov->lov_qos.lq_rw_sem);
out_nolock:
- if (pool != NULL)
- read_unlock(&pool_tgt_rwlock(pool));
+ if (pool != NULL) {
+ up_read(&pool_tgt_rw_sem(pool));
+ /* put back ref got by lov_find_pool() */
+ lh_put(lov->lov_pools_hash_body, &pool->pool_hash);
+ }
if (rc == -EAGAIN)
rc = alloc_rr(lov, idx_arr, stripe_cnt, poolname, flags);
--
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