[SCSI] libiscsi, iscsi_tcp: iscsi pool cleanup

iscsi_pool_init simplified

iscsi_pool_init currently has a lot of duplicate kfree() calls it does
when some allocation fails. This patch simplifies the code a little by
using iscsi_pool_free to tear down the pool in case of an error.

iscsi_pool_init also returns a copy of the item array to the caller.
Not all callers use this array, so we make it optional.

Instead of allocating a second array and return that, allocate just one
array, of twice the size.

Update users of iscsi_pool_{init,free}

This patch drops the (now useless) second argument to
iscsi_pool_free, and updates all callers.

It also removes the ctask->r2ts array, which was never
used anyway. Since the items argument to iscsi_pool_init
is now optional, we can pass NULL instead.

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 45 insertions, 45 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 491845f18710..f79a457099e6 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -1998,8 +1998,7 @@ iscsi_r2tpool_alloc(struct iscsi_session *session)
                  */
 
                 /* R2T pool */
-                if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
-                                    (void***)&tcp_ctask->r2ts,
+                if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4, NULL,
                                     sizeof(struct iscsi_r2t_info))) {
                         goto r2t_alloc_fail;
                 }
@@ -2008,8 +2007,7 @@ iscsi_r2tpool_alloc(struct iscsi_session *session)
                 tcp_ctask->r2tqueue = kfifo_alloc(
                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
-                        iscsi_pool_free(&tcp_ctask->r2tpool,
-                                        (void**)tcp_ctask->r2ts);
+                        iscsi_pool_free(&tcp_ctask->r2tpool);
                         goto r2t_alloc_fail;
                 }
         }
@@ -2022,8 +2020,7 @@ r2t_alloc_fail:
                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 
                 kfifo_free(tcp_ctask->r2tqueue);
-                iscsi_pool_free(&tcp_ctask->r2tpool,
-                                (void**)tcp_ctask->r2ts);
+                iscsi_pool_free(&tcp_ctask->r2tpool);
         }
         return -ENOMEM;
 }
@@ -2038,8 +2035,7 @@ iscsi_r2tpool_free(struct iscsi_session *session)
                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 
                 kfifo_free(tcp_ctask->r2tqueue);
-                iscsi_pool_free(&tcp_ctask->r2tpool,
-                                (void**)tcp_ctask->r2ts);
+                iscsi_pool_free(&tcp_ctask->r2tpool);
         }
 }
 
diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index eb3784f949fd..d49d87611e82 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -175,9 +175,8 @@ struct iscsi_tcp_cmd_task {
         uint32_t                exp_datasn;             /* expected target's R2TSN/DataSN */
         int                     data_offset;
         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
-        struct iscsi_queue      r2tpool;
+        struct iscsi_pool       r2tpool;
         struct kfifo            *r2tqueue;
-        struct iscsi_r2t_info   **r2ts;
         int                     digest_count;
         uint32_t                immdigest;              /* for imm data */
         struct iscsi_buf        immbuf;                 /* for imm data digest */
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 59365864c989..d43f909a022c 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1413,59 +1413,64 @@ done:
 }
 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
 
+/*
+ * Pre-allocate a pool of @max items of @item_size. By default, the pool
+ * should be accessed via kfifo_{get,put} on q->queue.
+ * Optionally, the caller can obtain the array of object pointers
+ * by passing in a non-NULL @items pointer
+ */
 int
-iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
+iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
 {
-        int i;
+        int i, num_arrays = 1;
 
-        *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
-        if (*items == NULL)
-                return -ENOMEM;
+        memset(q, 0, sizeof(*q));
 
         q->max = max;
-        q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
-        if (q->pool == NULL) {
-                kfree(*items);
-                return -ENOMEM;
-        }
+
+        /* If the user passed an items pointer, he wants a copy of
+         * the array. */
+        if (items)
+                num_arrays++;
+        q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
+        if (q->pool == NULL)
+                goto enomem;
 
         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
                               GFP_KERNEL, NULL);
-        if (q->queue == ERR_PTR(-ENOMEM)) {
-                kfree(q->pool);
-                kfree(*items);
-                return -ENOMEM;
-        }
+        if (q->queue == ERR_PTR(-ENOMEM))
+                goto enomem;
 
         for (i = 0; i < max; i++) {
-                q->pool[i] = kmalloc(item_size, GFP_KERNEL);
+                q->pool[i] = kzalloc(item_size, GFP_KERNEL);
                 if (q->pool[i] == NULL) {
-                        int j;
-
-                        for (j = 0; j < i; j++)
-                                kfree(q->pool[j]);
-
-                        kfifo_free(q->queue);
-                        kfree(q->pool);
-                        kfree(*items);
-                        return -ENOMEM;
+                        q->max = i;
+                        goto enomem;
                 }
-                memset(q->pool[i], 0, item_size);
-                (*items)[i] = q->pool[i];
                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
         }
+
+        if (items) {
+                *items = q->pool + max;
+                memcpy(*items, q->pool, max * sizeof(void *));
+        }
+
         return 0;
+
+enomem:
+        iscsi_pool_free(q);
+        return -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(iscsi_pool_init);
 
-void iscsi_pool_free(struct iscsi_queue *q, void **items)
+void iscsi_pool_free(struct iscsi_pool *q)
 {
         int i;
 
         for (i = 0; i < q->max; i++)
-                kfree(items[i]);
-        kfree(q->pool);
-        kfree(items);
+                kfree(q->pool[i]);
+        if (q->pool)
+                kfree(q->pool);
 }
 EXPORT_SYMBOL_GPL(iscsi_pool_free);
 
@@ -1610,9 +1615,9 @@ module_put:
 cls_session_fail:
         scsi_remove_host(shost);
 add_host_fail:
-        iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
+        iscsi_pool_free(&session->mgmtpool);
 mgmtpool_alloc_fail:
-        iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
+        iscsi_pool_free(&session->cmdpool);
 cmdpool_alloc_fail:
         scsi_host_put(shost);
         return NULL;
@@ -1635,8 +1640,8 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
         iscsi_unblock_session(cls_session);
         scsi_remove_host(shost);
 
-        iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
-        iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
+        iscsi_pool_free(&session->mgmtpool);
+        iscsi_pool_free(&session->cmdpool);
 
         kfree(session->password);
         kfree(session->password_in);