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path: root/drivers/scsi/libfc/fc_exch.c
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Diffstat (limited to 'drivers/scsi/libfc/fc_exch.c')
-rw-r--r--drivers/scsi/libfc/fc_exch.c48
1 files changed, 40 insertions, 8 deletions
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index ec2a1aec235..d21367d3305 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -67,6 +67,11 @@ struct workqueue_struct *fc_exch_workqueue;
struct fc_exch_pool {
u16 next_index;
u16 total_exches;
+
+ /* two cache of free slot in exch array */
+ u16 left;
+ u16 right;
+
spinlock_t lock;
struct list_head ex_list;
};
@@ -108,7 +113,6 @@ struct fc_exch_mgr {
atomic_t non_bls_resp;
} stats;
};
-#define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
/**
* struct fc_exch_mgr_anchor - primary structure for list of EMs
@@ -397,13 +401,23 @@ static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
static void fc_exch_delete(struct fc_exch *ep)
{
struct fc_exch_pool *pool;
+ u16 index;
pool = ep->pool;
spin_lock_bh(&pool->lock);
WARN_ON(pool->total_exches <= 0);
pool->total_exches--;
- fc_exch_ptr_set(pool, (ep->xid - ep->em->min_xid) >> fc_cpu_order,
- NULL);
+
+ /* update cache of free slot */
+ index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
+ if (pool->left == FC_XID_UNKNOWN)
+ pool->left = index;
+ else if (pool->right == FC_XID_UNKNOWN)
+ pool->right = index;
+ else
+ pool->next_index = index;
+
+ fc_exch_ptr_set(pool, index, NULL);
list_del(&ep->ex_list);
spin_unlock_bh(&pool->lock);
fc_exch_release(ep); /* drop hold for exch in mp */
@@ -636,10 +650,13 @@ static void fc_exch_timeout(struct work_struct *work)
if (e_stat & ESB_ST_ABNORMAL)
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
- if (!rc)
- fc_exch_delete(ep);
if (resp)
resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
+ if (!rc) {
+ /* delete the exchange if it's already being aborted */
+ fc_exch_delete(ep);
+ return;
+ }
fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
goto done;
}
@@ -679,6 +696,19 @@ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
pool = per_cpu_ptr(mp->pool, cpu);
spin_lock_bh(&pool->lock);
put_cpu();
+
+ /* peek cache of free slot */
+ if (pool->left != FC_XID_UNKNOWN) {
+ index = pool->left;
+ pool->left = FC_XID_UNKNOWN;
+ goto hit;
+ }
+ if (pool->right != FC_XID_UNKNOWN) {
+ index = pool->right;
+ pool->right = FC_XID_UNKNOWN;
+ goto hit;
+ }
+
index = pool->next_index;
/* allocate new exch from pool */
while (fc_exch_ptr_get(pool, index)) {
@@ -687,7 +717,7 @@ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
goto err;
}
pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
-
+hit:
fc_exch_hold(ep); /* hold for exch in mp */
spin_lock_init(&ep->ex_lock);
/*
@@ -1247,7 +1277,7 @@ static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
list_for_each_entry(ema, &lport->ema_list, ema_list)
if ((!ema->match || ema->match(fp)) &&
- fc_seq_lookup_recip(lport, ema->mp, fp) != FC_RJT_NONE)
+ fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
break;
return fr_seq(fp);
}
@@ -1343,7 +1373,7 @@ static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
}
if (ep->esb_stat & ESB_ST_COMPLETE) {
atomic_inc(&mp->stats.xid_not_found);
- goto out;
+ goto rel;
}
if (ep->rxid == FC_XID_UNKNOWN)
ep->rxid = ntohs(fh->fh_rx_id);
@@ -2181,6 +2211,8 @@ struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
goto free_mempool;
for_each_possible_cpu(cpu) {
pool = per_cpu_ptr(mp->pool, cpu);
+ pool->left = FC_XID_UNKNOWN;
+ pool->right = FC_XID_UNKNOWN;
spin_lock_init(&pool->lock);
INIT_LIST_HEAD(&pool->ex_list);
}