From 92ff15288747b80730f0132e9c98403370c27b34 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Thu, 25 Jun 2015 15:00:19 -0700 Subject: [PATCH] zram: return zram device_id from zram_add() This patch prepares zram to enable on-demand device creation. zram_add() performs automatic device_id assignment and returns new device id (>= 0) or error code (< 0). Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zram_drv.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 4f76cf3..a52a819 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1153,20 +1153,24 @@ static struct attribute_group zram_disk_attr_group = { .attrs = zram_disk_attrs, }; -static int zram_add(int device_id) +/* + * Allocate and initialize new zram device. the function returns + * '>= 0' device_id upon success, and negative value otherwise. + */ +static int zram_add(void) { struct zram *zram; struct request_queue *queue; - int ret; + int ret, device_id; zram = kzalloc(sizeof(struct zram), GFP_KERNEL); if (!zram) return -ENOMEM; - ret = idr_alloc(&zram_index_idr, zram, device_id, - device_id + 1, GFP_KERNEL); + ret = idr_alloc(&zram_index_idr, zram, 0, 0, GFP_KERNEL); if (ret < 0) goto out_free_dev; + device_id = ret; init_rwsem(&zram->init_lock); @@ -1240,7 +1244,7 @@ static int zram_add(int device_id) zram->max_comp_streams = 1; pr_info("Added device: %s\n", zram->disk->disk_name); - return 0; + return device_id; out_free_disk: del_gendisk(zram->disk); @@ -1287,7 +1291,7 @@ static void destroy_devices(void) static int __init zram_init(void) { - int ret, dev_id; + int ret; zram_major = register_blkdev(0, "zram"); if (zram_major <= 0) { @@ -1295,10 +1299,11 @@ static int __init zram_init(void) return -EBUSY; } - for (dev_id = 0; dev_id < num_devices; dev_id++) { - ret = zram_add(dev_id); - if (ret != 0) + while (num_devices != 0) { + ret = zram_add(); + if (ret < 0) goto out_error; + num_devices--; } return 0; -- 2.7.4