diff options
| -rw-r--r-- | drivers/scsi/ch.c | 71 |
1 files changed, 40 insertions, 31 deletions
diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c index 765f2fc001aa..2b07014cbc83 100644 --- a/drivers/scsi/ch.c +++ b/drivers/scsi/ch.c @@ -21,6 +21,7 @@ #include <linux/compat.h> #include <linux/chio.h> /* here are all the ioctls */ #include <linux/mutex.h> +#include <linux/idr.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -33,6 +34,7 @@ #define CH_DT_MAX 16 #define CH_TYPES 8 +#define CH_MAX_DEVS 128 MODULE_DESCRIPTION("device driver for scsi media changer devices"); MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org>"); @@ -113,9 +115,8 @@ typedef struct { struct mutex lock; } scsi_changer; -static LIST_HEAD(ch_devlist); -static DEFINE_SPINLOCK(ch_devlist_lock); -static int ch_devcount; +static DEFINE_IDR(ch_index_idr); +static DEFINE_SPINLOCK(ch_index_lock); static struct scsi_driver ch_template = { @@ -598,20 +599,17 @@ ch_release(struct inode *inode, struct file *file) static int ch_open(struct inode *inode, struct file *file) { - scsi_changer *tmp, *ch; + scsi_changer *ch; int minor = iminor(inode); - spin_lock(&ch_devlist_lock); - ch = NULL; - list_for_each_entry(tmp,&ch_devlist,list) { - if (tmp->minor == minor) - ch = tmp; - } + spin_lock(&ch_index_lock); + ch = idr_find(&ch_index_idr, minor); + if (NULL == ch || scsi_device_get(ch->device)) { - spin_unlock(&ch_devlist_lock); + spin_unlock(&ch_index_lock); return -ENXIO; } - spin_unlock(&ch_devlist_lock); + spin_unlock(&ch_index_lock); file->private_data = ch; return 0; @@ -914,6 +912,7 @@ static int ch_probe(struct device *dev) { struct scsi_device *sd = to_scsi_device(dev); struct class_device *class_dev; + int minor, ret = -ENOMEM; scsi_changer *ch; if (sd->type != TYPE_MEDIUM_CHANGER) @@ -923,7 +922,22 @@ static int ch_probe(struct device *dev) if (NULL == ch) return -ENOMEM; - ch->minor = ch_devcount; + if (!idr_pre_get(&ch_index_idr, GFP_KERNEL)) + goto free_ch; + + spin_lock(&ch_index_lock); + ret = idr_get_new(&ch_index_idr, ch, &minor); + spin_unlock(&ch_index_lock); + + if (ret) + goto free_ch; + + if (minor > CH_MAX_DEVS) { + ret = -ENODEV; + goto remove_idr; + } + + ch->minor = minor; sprintf(ch->name,"ch%d",ch->minor); class_dev = class_device_create(ch_sysfs_class, NULL, @@ -932,8 +946,8 @@ static int ch_probe(struct device *dev) if (IS_ERR(class_dev)) { printk(KERN_WARNING "ch%d: class_device_create failed\n", ch->minor); - kfree(ch); - return PTR_ERR(class_dev); + ret = PTR_ERR(class_dev); + goto remove_idr; } mutex_init(&ch->lock); @@ -942,35 +956,29 @@ static int ch_probe(struct device *dev) if (init) ch_init_elem(ch); + dev_set_drvdata(dev, ch); sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name); - spin_lock(&ch_devlist_lock); - list_add_tail(&ch->list,&ch_devlist); - ch_devcount++; - spin_unlock(&ch_devlist_lock); return 0; +remove_idr: + idr_remove(&ch_index_idr, minor); +free_ch: + kfree(ch); + return ret; } static int ch_remove(struct device *dev) { - struct scsi_device *sd = to_scsi_device(dev); - scsi_changer *tmp, *ch; + scsi_changer *ch = dev_get_drvdata(dev); - spin_lock(&ch_devlist_lock); - ch = NULL; - list_for_each_entry(tmp,&ch_devlist,list) { - if (tmp->device == sd) - ch = tmp; - } - BUG_ON(NULL == ch); - list_del(&ch->list); - spin_unlock(&ch_devlist_lock); + spin_lock(&ch_index_lock); + idr_remove(&ch_index_idr, ch->minor); + spin_unlock(&ch_index_lock); class_device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor)); kfree(ch->dt); kfree(ch); - ch_devcount--; return 0; } @@ -1007,6 +1015,7 @@ static void __exit exit_ch_module(void) scsi_unregister_driver(&ch_template.gendrv); unregister_chrdev(SCSI_CHANGER_MAJOR, "ch"); class_destroy(ch_sysfs_class); + idr_destroy(&ch_index_idr); } module_init(init_ch_module); |