3 files changed, 27 insertions, 21 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 7f6820becf10..9b94427be145 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -58,9 +58,6 @@ static int mtd_devs = 0;
 /* MTD devices specification parameters */
 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
 
-/* Number of UBI devices in system */
-int ubi_devices_cnt;
-
 /* All UBI devices in system */
 struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
 
@@ -566,26 +563,39 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
         }
 
         /* Check if we already have the same MTD device attached */
-        for (i = 0; i < ubi_devices_cnt; i++)
-                if (ubi_devices[i]->mtd->index == mtd->index) {
+        for (i = 0; i < UBI_MAX_DEVICES; i++)
+                ubi = ubi_devices[i];
+                if (ubi && ubi->mtd->index == mtd->index) {
                         ubi_err("mtd%d is already attached to ubi%d",
                                 mtd->index, i);
                         err = -EINVAL;
                         goto out_mtd;
                 }
 
-        ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
-                                                     GFP_KERNEL);
+        ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
         if (!ubi) {
                 err = -ENOMEM;
                 goto out_mtd;
         }
 
-        ubi->ubi_num = ubi_devices_cnt;
         ubi->mtd = mtd;
 
+        /* Search for an empty slot in the @ubi_devices array */
+        ubi->ubi_num = -1;
+        for (i = 0; i < UBI_MAX_DEVICES; i++)
+                if (!ubi_devices[i]) {
+                        ubi->ubi_num = i;
+                        break;
+                }
+
+        if (ubi->ubi_num == -1) {
+                ubi_err("only %d UBI devices may be created", UBI_MAX_DEVICES);
+                err = -ENFILE;
+                goto out_free;
+        }
+
         dbg_msg("attaching mtd%d to ubi%d: VID header offset %d data offset %d",
-                ubi->mtd->index, ubi_devices_cnt, vid_hdr_offset, data_offset);
+                ubi->mtd->index, ubi->ubi_num, vid_hdr_offset, data_offset);
 
         ubi->vid_hdr_offset = vid_hdr_offset;
         ubi->leb_start = data_offset;
@@ -619,7 +629,7 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
         if (err)
                 goto out_detach;
 
-        ubi_msg("attached mtd%d to ubi%d", ubi->mtd->index, ubi_devices_cnt);
+        ubi_msg("attached mtd%d to ubi%d", ubi->mtd->index, ubi->ubi_num);
         ubi_msg("MTD device name:            \"%s\"", ubi->mtd->name);
         ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
         ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
@@ -648,7 +658,7 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
                 wake_up_process(ubi->bgt_thread);
         }
 
-        ubi_devices_cnt += 1;
+        ubi_devices[ubi->ubi_num] = ubi;
         return 0;
 
 out_detach:
@@ -664,7 +674,6 @@ out_free:
         kfree(ubi);
 out_mtd:
         put_mtd_device(mtd);
-        ubi_devices[ubi_devices_cnt] = NULL;
         return err;
 }
 
@@ -689,8 +698,6 @@ static void detach_mtd_dev(struct ubi_device *ubi)
 #endif
         kfree(ubi_devices[ubi_num]);
         ubi_devices[ubi_num] = NULL;
-        ubi_devices_cnt -= 1;
-        ubi_assert(ubi_devices_cnt >= 0);
         ubi_msg("mtd%d is detached from ubi%d", mtd_num, ubi_num);
 }
 
@@ -770,10 +777,11 @@ module_init(ubi_init);
 
 static void __exit ubi_exit(void)
 {
-        int i, n = ubi_devices_cnt;
+        int i;
 
-        for (i = 0; i < n; i++)
-                detach_mtd_dev(ubi_devices[i]);
+        for (i = 0; i < UBI_MAX_DEVICES; i++)
+                if (ubi_devices[i])
+                        detach_mtd_dev(ubi_devices[i]);
         kmem_cache_destroy(ubi_wl_entry_slab);
         kmem_cache_destroy(ubi_ltree_slab);
         class_remove_file(ubi_class, &ubi_version);
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 12777da47d3b..7697eda2d58c 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -60,7 +60,7 @@ static struct ubi_device *major_to_device(int major)
 {
         int i;
 
-        for (i = 0; i < ubi_devices_cnt; i++)
+        for (i = 0; i < UBI_MAX_DEVICES; i++)
                 if (ubi_devices[i] && MAJOR(ubi_devices[i]->cdev.dev) == major)
                         return ubi_devices[i];
         BUG();
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index b7c93173e77b..23875bf6aa3b 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -94,9 +94,6 @@ enum {
         UBI_IO_BITFLIPS
 };
 
-extern int ubi_devices_cnt;
-extern struct ubi_device *ubi_devices[];
-
 /**
  * struct ubi_wl_entry - wear-leveling entry.
  * @rb: link in the corresponding RB-tree
@@ -401,6 +398,7 @@ extern struct kmem_cache *ubi_ltree_slab;
 extern struct kmem_cache *ubi_wl_entry_slab;
 extern struct file_operations ubi_cdev_operations;
 extern struct file_operations ubi_vol_cdev_operations;
+extern struct ubi_device *ubi_devices[];
 extern struct class *ubi_class;
 
 /* vtbl.c */