1 files changed, 18 insertions, 19 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 806497225603..1f7e9e914d34 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -500,6 +500,8 @@ out:
 }
 
 #ifdef CONFIG_ZRAM_WRITEBACK
+#define INVALID_BDEV_BLOCK		(~0UL)
+
 struct zram_wb_ctl {
 	/* idle list is accessed only by the writeback task, no concurency */
 	struct list_head idle_reqs;
@@ -746,23 +748,20 @@ out:
 	return err;
 }
 
-static unsigned long alloc_block_bdev(struct zram *zram)
+static unsigned long zram_reserve_bdev_block(struct zram *zram)
 {
-	unsigned long blk_idx = 1;
-retry:
-	/* skip 0 bit to confuse zram.handle = 0 */
-	blk_idx = find_next_zero_bit(zram->bitmap, zram->nr_pages, blk_idx);
-	if (blk_idx == zram->nr_pages)
-		return 0;
+	unsigned long blk_idx;
 
-	if (test_and_set_bit(blk_idx, zram->bitmap))
-		goto retry;
+	blk_idx = find_next_zero_bit(zram->bitmap, zram->nr_pages, 0);
+	if (blk_idx == zram->nr_pages)
+		return INVALID_BDEV_BLOCK;
 
+	set_bit(blk_idx, zram->bitmap);
 	atomic64_inc(&zram->stats.bd_count);
 	return blk_idx;
 }
 
-static void free_block_bdev(struct zram *zram, unsigned long blk_idx)
+static void zram_release_bdev_block(struct zram *zram, unsigned long blk_idx)
 {
 	int was_set;
 
@@ -887,7 +886,7 @@ static int zram_writeback_complete(struct zram *zram, struct zram_wb_req *req)
 		 * (if enabled).
 		 */
 		zram_account_writeback_rollback(zram);
-		free_block_bdev(zram, req->blk_idx);
+		zram_release_bdev_block(zram, req->blk_idx);
 		return err;
 	}
 
@@ -901,7 +900,7 @@ static int zram_writeback_complete(struct zram *zram, struct zram_wb_req *req)
 	 * finishes.
 	 */
 	if (!zram_test_flag(zram, index, ZRAM_PP_SLOT)) {
-		free_block_bdev(zram, req->blk_idx);
+		zram_release_bdev_block(zram, req->blk_idx);
 		goto out;
 	}
 
@@ -990,8 +989,8 @@ static int zram_writeback_slots(struct zram *zram,
 				struct zram_pp_ctl *ctl,
 				struct zram_wb_ctl *wb_ctl)
 {
+	unsigned long blk_idx = INVALID_BDEV_BLOCK;
 	struct zram_wb_req *req = NULL;
-	unsigned long blk_idx = 0;
 	struct zram_pp_slot *pps;
 	int ret = 0, err = 0;
 	u32 index = 0;
@@ -1023,9 +1022,9 @@ static int zram_writeback_slots(struct zram *zram,
 				ret = err;
 		}
 
-		if (!blk_idx) {
-			blk_idx = alloc_block_bdev(zram);
-			if (!blk_idx) {
+		if (blk_idx == INVALID_BDEV_BLOCK) {
+			blk_idx = zram_reserve_bdev_block(zram);
+			if (blk_idx == INVALID_BDEV_BLOCK) {
 				ret = -ENOSPC;
 				break;
 			}
@@ -1059,7 +1058,7 @@ static int zram_writeback_slots(struct zram *zram,
 		__bio_add_page(&req->bio, req->page, PAGE_SIZE, 0);
 
 		zram_submit_wb_request(zram, wb_ctl, req);
-		blk_idx = 0;
+		blk_idx = INVALID_BDEV_BLOCK;
 		req = NULL;
 		cond_resched();
 		continue;
@@ -1366,7 +1365,7 @@ static int read_from_bdev(struct zram *zram, struct page *page,
 	return -EIO;
 }
 
-static void free_block_bdev(struct zram *zram, unsigned long blk_idx)
+static void zram_release_bdev_block(struct zram *zram, unsigned long blk_idx)
 {
 }
 #endif
@@ -1890,7 +1889,7 @@ static void zram_free_page(struct zram *zram, size_t index)
 
 	if (zram_test_flag(zram, index, ZRAM_WB)) {
 		zram_clear_flag(zram, index, ZRAM_WB);
-		free_block_bdev(zram, zram_get_handle(zram, index));
+		zram_release_bdev_block(zram, zram_get_handle(zram, index));
 		goto out;
 	}