cdrom: use list_head for cdrom_device_info list

Use list_head for cdrom_device_info list instead of opencoded
singly list handling.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 326ef1b..c4213b7 100644 (file)
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -362,7 +362,7 @@ static int cdrom_get_disc_info(struct cdrom_device_info *cdi, disc_information *
 
 static void cdrom_sysctl_register(void);
 
-static struct cdrom_device_info *topCdromPtr;
+static LIST_HEAD(cdrom_list);
 
 static int cdrom_dummy_generic_packet(struct cdrom_device_info *cdi,
                                      struct packet_command *cgc)
@@ -436,35 +436,18 @@ int register_cdrom(struct cdrom_device_info *cdi)
 
        cdinfo(CD_REG_UNREG, "drive \"/dev/%s\" registered\n", cdi->name);
        mutex_lock(&cdrom_mutex);
-       cdi->next = topCdromPtr;        
-       topCdromPtr = cdi;
+       list_add(&cdi->list, &cdrom_list);
        mutex_unlock(&cdrom_mutex);
        return 0;
 }
 #undef ENSURE
 
-int unregister_cdrom(struct cdrom_device_info *unreg)
+int unregister_cdrom(struct cdrom_device_info *cdi)
 {
-       struct cdrom_device_info *cdi, *prev;
        cdinfo(CD_OPEN, "entering unregister_cdrom\n"); 
 
-       prev = NULL;
        mutex_lock(&cdrom_mutex);
-       cdi = topCdromPtr;
-       while (cdi && cdi != unreg) {
-               prev = cdi;
-               cdi = cdi->next;
-       }
-
-       if (cdi == NULL) {
-               mutex_unlock(&cdrom_mutex);
-               return -2;
-       }
-       if (prev)
-               prev->next = cdi->next;
-       else
-               topCdromPtr = cdi->next;
-
+       list_del(&cdi->list);
        mutex_unlock(&cdrom_mutex);
 
        if (cdi->exit)
@@ -3306,7 +3289,7 @@ static int cdrom_print_info(const char *header, int val, char *info,
 
        *pos += ret;
 
-       for (cdi = topCdromPtr; cdi; cdi = cdi->next) {
+       list_for_each_entry(cdi, &cdrom_list, list) {
                switch (option) {
                case CTL_NAME:
                        ret = scnprintf(info + *pos, max_size - *pos,
@@ -3428,7 +3411,7 @@ static void cdrom_update_settings(void)
        struct cdrom_device_info *cdi;
 
        mutex_lock(&cdrom_mutex);
-       for (cdi = topCdromPtr; cdi != NULL; cdi = cdi->next) {
+       list_for_each_entry(cdi, &cdrom_list, list) {
                if (autoclose && CDROM_CAN(CDC_CLOSE_TRAY))
                        cdi->options |= CDO_AUTO_CLOSE;
                else if (!autoclose)

diff --git a/include/linux/cdrom.h b/include/linux/cdrom.h
index a5cd204..40e05d0 100644 (file)
--- a/include/linux/cdrom.h
+++ b/include/linux/cdrom.h
@@ -910,6 +910,7 @@ struct mode_page_header {
 #ifdef __KERNEL__
 #include <linux/fs.h>          /* not really needed, later.. */
 #include <linux/device.h>
+#include <linux/list.h>
 
 struct packet_command
 {
@@ -934,7 +935,7 @@ struct packet_command
 /* Uniform cdrom data structures for cdrom.c */
 struct cdrom_device_info {
        struct cdrom_device_ops  *ops;  /* link to device_ops */
-       struct cdrom_device_info *next; /* next device_info for this major */
+       struct list_head list;          /* linked list of all device_info */
        struct gendisk *disk;           /* matching block layer disk */
        void *handle;                   /* driver-dependent data */
 /* specifications */