[PATCH] pktcdvd: reusability of procfs functions

This patch makes some of the procfs functions reusable (for
coming sysfs patch e.g.):
pkt_setup_dev()
pkt_remove_dev()
...

Signed-off-by: Thomas Maier <balagi@justmail.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 45 insertions, 27 deletions

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index e45eaa264119..7e7b892f621a 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
+ * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
  *
  * May be copied or modified under the terms of the GNU General Public
  * License.  See linux/COPYING for more information.
@@ -2436,36 +2437,33 @@ static struct block_device_operations pktcdvd_ops = {
 /*
  * Set up mapping from pktcdvd device to CD-ROM device.
  */
-static int pkt_setup_dev(struct pkt_ctrl_command *ctrl_cmd)
+static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 {
         int idx;
         int ret = -ENOMEM;
         struct pktcdvd_device *pd;
         struct gendisk *disk;
-        dev_t dev = new_decode_dev(ctrl_cmd->dev);
+
+        mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 
         for (idx = 0; idx < MAX_WRITERS; idx++)
                 if (!pkt_devs[idx])
                         break;
         if (idx == MAX_WRITERS) {
                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
-                return -EBUSY;
+                ret = -EBUSY;
+                goto out_mutex;
         }
 
         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
         if (!pd)
-                return ret;
+                goto out_mutex;
 
         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
                                                   sizeof(struct pkt_rb_node));
         if (!pd->rb_pool)
                 goto out_mem;
 
-        disk = alloc_disk(1);
-        if (!disk)
-                goto out_mem;
-        pd->disk = disk;
-
         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
         spin_lock_init(&pd->cdrw.active_list_lock);
@@ -2476,11 +2474,15 @@ static int pkt_setup_dev(struct pkt_ctrl_command *ctrl_cmd)
         init_waitqueue_head(&pd->wqueue);
         pd->bio_queue = RB_ROOT;
 
+        disk = alloc_disk(1);
+        if (!disk)
+                goto out_mem;
+        pd->disk = disk;
         disk->major = pktdev_major;
         disk->first_minor = idx;
         disk->fops = &pktcdvd_ops;
         disk->flags = GENHD_FL_REMOVABLE;
-        sprintf(disk->disk_name, DRIVER_NAME"%d", idx);
+        strcpy(disk->disk_name, pd->name);
         disk->private_data = pd;
         disk->queue = blk_alloc_queue(GFP_KERNEL);
         if (!disk->queue)
@@ -2492,8 +2494,12 @@ static int pkt_setup_dev(struct pkt_ctrl_command *ctrl_cmd)
                 goto out_new_dev;
 
         add_disk(disk);
+
         pkt_devs[idx] = pd;
-        ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
+        if (pkt_dev)
+                *pkt_dev = pd->pkt_dev;
+
+        mutex_unlock(&ctl_mutex);
         return 0;
 
 out_new_dev:
@@ -2504,17 +2510,22 @@ out_mem:
         if (pd->rb_pool)
                 mempool_destroy(pd->rb_pool);
         kfree(pd);
+out_mutex:
+        mutex_unlock(&ctl_mutex);
+        printk(DRIVER_NAME": setup of pktcdvd device failed\n");
         return ret;
 }
 
 /*
  * Tear down mapping from pktcdvd device to CD-ROM device.
  */
-static int pkt_remove_dev(struct pkt_ctrl_command *ctrl_cmd)
+static int pkt_remove_dev(dev_t pkt_dev)
 {
         struct pktcdvd_device *pd;
         int idx;
-        dev_t pkt_dev = new_decode_dev(ctrl_cmd->pkt_dev);
+        int ret = 0;
+
+        mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 
         for (idx = 0; idx < MAX_WRITERS; idx++) {
                 pd = pkt_devs[idx];
@@ -2523,12 +2534,14 @@ static int pkt_remove_dev(struct pkt_ctrl_command *ctrl_cmd)
         }
         if (idx == MAX_WRITERS) {
                 DPRINTK(DRIVER_NAME": dev not setup\n");
-                return -ENXIO;
+                ret = -ENXIO;
+                goto out;
         }
 
-        if (pd->refcnt > 0)
-                return -EBUSY;
-
+        if (pd->refcnt > 0) {
+                ret = -EBUSY;
+                goto out;
+        }
         if (!IS_ERR(pd->cdrw.thread))
                 kthread_stop(pd->cdrw.thread);
 
@@ -2547,12 +2560,19 @@ static int pkt_remove_dev(struct pkt_ctrl_command *ctrl_cmd)
 
         /* This is safe: open() is still holding a reference. */
         module_put(THIS_MODULE);
-        return 0;
+
+out:
+        mutex_unlock(&ctl_mutex);
+        return ret;
 }
 
 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
 {
-        struct pktcdvd_device *pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
+        struct pktcdvd_device *pd;
+
+        mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+
+        pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
         if (pd) {
                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
@@ -2561,6 +2581,8 @@ static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
                 ctrl_cmd->pkt_dev = 0;
         }
         ctrl_cmd->num_devices = MAX_WRITERS;
+
+        mutex_unlock(&ctl_mutex);
 }
 
 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
@@ -2568,6 +2590,7 @@ static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cm
         void __user *argp = (void __user *)arg;
         struct pkt_ctrl_command ctrl_cmd;
         int ret = 0;
+        dev_t pkt_dev = 0;
 
         if (cmd != PACKET_CTRL_CMD)
                 return -ENOTTY;
@@ -2579,21 +2602,16 @@ static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cm
         case PKT_CTRL_CMD_SETUP:
                 if (!capable(CAP_SYS_ADMIN))
                         return -EPERM;
-                mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-                ret = pkt_setup_dev(&ctrl_cmd);
-                mutex_unlock(&ctl_mutex);
+                ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
+                ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
                 break;
         case PKT_CTRL_CMD_TEARDOWN:
                 if (!capable(CAP_SYS_ADMIN))
                         return -EPERM;
-                mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-                ret = pkt_remove_dev(&ctrl_cmd);
-                mutex_unlock(&ctl_mutex);
+                ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
                 break;
         case PKT_CTRL_CMD_STATUS:
-                mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
                 pkt_get_status(&ctrl_cmd);
-                mutex_unlock(&ctl_mutex);
                 break;
         default:
                 return -ENOTTY;