From 598443a2124618fc8fe5a8bae32c129666ac3eab Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 23 Jul 2007 09:33:26 +0900 Subject: [PATCH] [SCSI] bsg: use lib/idr.c to find a unique minor number This replaces the current linear search for a unique minor number with lib/idr.c. Signed-off-by: FUJITA Tomonori Acked-by: Jens Axboe Signed-off-by: James Bottomley --- block/bsg.c | 69 ++++++++++++++++++++------------------------- include/linux/bsg.h | 1 - 2 files changed, 30 insertions(+), 40 deletions(-) diff --git a/block/bsg.c b/block/bsg.c index b571869928a8..8e4de53311e1 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -70,13 +71,12 @@ enum { #endif static DEFINE_MUTEX(bsg_mutex); -static int bsg_device_nr, bsg_minor_idx; +static DEFINE_IDR(bsg_minor_idr); #define BSG_LIST_ARRAY_SIZE 8 static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE]; static struct class *bsg_class; -static LIST_HEAD(bsg_class_list); static int bsg_major; static struct kmem_cache *bsg_cmd_cachep; @@ -781,23 +781,18 @@ static struct bsg_device *__bsg_get_device(int minor) static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file) { - struct bsg_device *bd = __bsg_get_device(iminor(inode)); - struct bsg_class_device *bcd, *__bcd; + struct bsg_device *bd; + struct bsg_class_device *bcd; + bd = __bsg_get_device(iminor(inode)); if (bd) return bd; /* * find the class device */ - bcd = NULL; mutex_lock(&bsg_mutex); - list_for_each_entry(__bcd, &bsg_class_list, list) { - if (__bcd->minor == iminor(inode)) { - bcd = __bcd; - break; - } - } + bcd = idr_find(&bsg_minor_idr, iminor(inode)); mutex_unlock(&bsg_mutex); if (!bcd) @@ -936,13 +931,12 @@ void bsg_unregister_queue(struct request_queue *q) return; mutex_lock(&bsg_mutex); + idr_remove(&bsg_minor_idr, bcd->minor); sysfs_remove_link(&q->kobj, "bsg"); class_device_unregister(bcd->class_dev); put_device(bcd->dev); bcd->class_dev = NULL; bcd->dev = NULL; - list_del_init(&bcd->list); - bsg_device_nr--; mutex_unlock(&bsg_mutex); } EXPORT_SYMBOL_GPL(bsg_unregister_queue); @@ -950,9 +944,9 @@ EXPORT_SYMBOL_GPL(bsg_unregister_queue); int bsg_register_queue(struct request_queue *q, struct device *gdev, const char *name) { - struct bsg_class_device *bcd, *__bcd; + struct bsg_class_device *bcd; dev_t dev; - int ret = -EMFILE; + int ret, minor; struct class_device *class_dev = NULL; const char *devname; @@ -969,28 +963,26 @@ int bsg_register_queue(struct request_queue *q, struct device *gdev, bcd = &q->bsg_dev; memset(bcd, 0, sizeof(*bcd)); - INIT_LIST_HEAD(&bcd->list); mutex_lock(&bsg_mutex); - if (bsg_device_nr == BSG_MAX_DEVS) { - printk(KERN_ERR "bsg: too many bsg devices\n"); - goto err; - } -retry: - list_for_each_entry(__bcd, &bsg_class_list, list) { - if (__bcd->minor == bsg_minor_idx) { - bsg_minor_idx++; - if (bsg_minor_idx == BSG_MAX_DEVS) - bsg_minor_idx = 0; - goto retry; - } + ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL); + if (!ret) { + ret = -ENOMEM; + goto unlock; } - bcd->minor = bsg_minor_idx++; - if (bsg_minor_idx == BSG_MAX_DEVS) - bsg_minor_idx = 0; + ret = idr_get_new(&bsg_minor_idr, bcd, &minor); + if (ret < 0) + goto unlock; + if (minor >= BSG_MAX_DEVS) { + printk(KERN_ERR "bsg: too many bsg devices\n"); + ret = -EINVAL; + goto remove_idr; + } + + bcd->minor = minor; bcd->queue = q; bcd->dev = get_device(gdev); dev = MKDEV(bsg_major, bcd->minor); @@ -998,27 +990,26 @@ int bsg_register_queue(struct request_queue *q, struct device *gdev, devname); if (IS_ERR(class_dev)) { ret = PTR_ERR(class_dev); - goto err_put; + goto put_dev; } bcd->class_dev = class_dev; if (q->kobj.sd) { ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg"); if (ret) - goto err_unregister; + goto unregister_class_dev; } - list_add_tail(&bcd->list, &bsg_class_list); - bsg_device_nr++; - mutex_unlock(&bsg_mutex); return 0; -err_unregister: +unregister_class_dev: class_device_unregister(class_dev); -err_put: +put_dev: put_device(gdev); -err: +remove_idr: + idr_remove(&bsg_minor_idr, minor); +unlock: mutex_unlock(&bsg_mutex); return ret; } diff --git a/include/linux/bsg.h b/include/linux/bsg.h index f415f89e0ac8..241eed03e42c 100644 --- a/include/linux/bsg.h +++ b/include/linux/bsg.h @@ -53,7 +53,6 @@ struct bsg_class_device { struct class_device *class_dev; struct device *dev; int minor; - struct list_head list; struct request_queue *queue; }; -- GitLab