UBI: provide helpers to allocate and free aeb elements

This not only hides the aeb allocation internals (which is always good in
case we ever want to change the allocation system), but also helps us
factorize the initialization of some common fields (ec and pnum).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

drivers/mtd/ubi/fastmap.c

@@ -145,12 +145,10 @@ static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 {
 	struct ubi_ainf_peb *aeb;
 
-	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
+	aeb = ubi_alloc_aeb(ai, pnum, ec);
 	if (!aeb)
 		return -ENOMEM;
 
-	aeb->pnum = pnum;
-	aeb->ec = ec;
 	aeb->lnum = -1;
 	aeb->scrub = scrub;
 	aeb->copy_flag = aeb->sqnum = 0;
@@ -276,7 +274,7 @@ static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 		 */
 		if (aeb->pnum == new_aeb->pnum) {
 			ubi_assert(aeb->lnum == new_aeb->lnum);
-			kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+			ubi_free_aeb(ai, new_aeb);
 
 			return 0;
 		}
@@ -287,13 +285,10 @@ static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 
 		/* new_aeb is newer */
 		if (cmp_res & 1) {
-			victim = kmem_cache_alloc(ai->aeb_slab_cache,
-				GFP_KERNEL);
+			victim = ubi_alloc_aeb(ai, aeb->ec, aeb->pnum);
 			if (!victim)
 				return -ENOMEM;
 
-			victim->ec = aeb->ec;
-			victim->pnum = aeb->pnum;
 			list_add_tail(&victim->u.list, &ai->erase);
 
 			if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
@@ -307,7 +302,7 @@ static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 			aeb->pnum = new_aeb->pnum;
 			aeb->copy_flag = new_vh->copy_flag;
 			aeb->scrub = new_aeb->scrub;
-			kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+			ubi_free_aeb(ai, new_aeb);
 
 		/* new_aeb is older */
 		} else {
@@ -353,7 +348,7 @@ static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 	struct ubi_ainf_volume *av;
 
 	if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
-		kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+		ubi_free_aeb(ai, new_aeb);
 
 		return 0;
 	}
@@ -362,7 +357,7 @@ static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 	av = ubi_find_av(ai, vol_id);
 	if (!av) {
 		ubi_err(ubi, "orphaned volume in fastmap pool!");
-		kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+		ubi_free_aeb(ai, new_aeb);
 		return UBI_BAD_FASTMAP;
 	}
 
@@ -390,7 +385,7 @@ static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 			if (aeb->pnum == pnum) {
 				rb_erase(&aeb->u.rb, &av->root);
 				av->leb_count--;
-				kmem_cache_free(ai->aeb_slab_cache, aeb);
+				ubi_free_aeb(ai, aeb);
 				return;
 			}
 		}
@@ -485,15 +480,12 @@ static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 			if (err == UBI_IO_BITFLIPS)
 				scrub = 1;
 
-			new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
-						   GFP_KERNEL);
+			new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 			if (!new_aeb) {
 				ret = -ENOMEM;
 				goto out;
 			}
 
-			new_aeb->ec = be64_to_cpu(ech->ec);
-			new_aeb->pnum = pnum;
 			new_aeb->lnum = be32_to_cpu(vh->lnum);
 			new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 			new_aeb->copy_flag = vh->copy_flag;
@@ -800,11 +792,11 @@ fail_bad:
 fail:
 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 		list_del(&tmp_aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
+		ubi_free_aeb(ai, tmp_aeb);
 	}
 	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 		list_del(&tmp_aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
+		ubi_free_aeb(ai, tmp_aeb);
 	}
 
 	return ret;