[SCSI] st: clean up device file creation and removal

This patch cleans up the st device file creation and removal.

Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

2 files changed, 91 insertions, 105 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 052622fdba02..ceca095e5d8d 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -193,7 +193,6 @@ static int st_remove(struct device *);
 
 static int do_create_sysfs_files(void);
 static void do_remove_sysfs_files(void);
-static int do_create_class_files(struct scsi_tape *, int, int);
 
 static struct scsi_driver st_template = {
         .owner                  = THIS_MODULE,
@@ -3990,16 +3989,98 @@ static const struct file_operations st_fops =
         .llseek =       noop_llseek,
 };
 
+static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
+{
+        int i, error;
+        dev_t cdev_devno;
+        struct cdev *cdev;
+        struct device *dev;
+        struct st_modedef *STm = &(tape->modes[mode]);
+        char name[10];
+        int dev_num = tape->index;
+
+        cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
+
+        cdev = cdev_alloc();
+        if (!cdev) {
+                pr_err("st%d: out of memory. Device not attached.\n", dev_num);
+                error = -ENOMEM;
+                goto out;
+        }
+        cdev->owner = THIS_MODULE;
+        cdev->ops = &st_fops;
+
+        error = cdev_add(cdev, cdev_devno, 1);
+        if (error) {
+                pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
+                       rew ? "non" : "auto", mode);
+                pr_err("st%d: Device not attached.\n", dev_num);
+                goto out_free;
+        }
+        STm->cdevs[rew] = cdev;
+
+        i = mode << (4 - ST_NBR_MODE_BITS);
+        snprintf(name, 10, "%s%s%s", rew ? "n" : "",
+                 tape->disk->disk_name, st_formats[i]);
+
+        dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
+                            cdev_devno, &tape->modes[mode], "%s", name);
+        if (IS_ERR(dev)) {
+                pr_err("st%d: device_create failed\n", dev_num);
+                error = PTR_ERR(dev);
+                goto out_free;
+        }
+
+        STm->devs[rew] = dev;
+
+        return 0;
+out_free:
+        cdev_del(STm->cdevs[rew]);
+        STm->cdevs[rew] = NULL;
+out:
+        return error;
+}
+
+static int create_cdevs(struct scsi_tape *tape)
+{
+        int mode, error;
+        for (mode = 0; mode < ST_NBR_MODES; ++mode) {
+                error = create_one_cdev(tape, mode, 0);
+                if (error)
+                        return error;
+                error = create_one_cdev(tape, mode, 1);
+                if (error)
+                        return error;
+        }
+
+        return sysfs_create_link(&tape->device->sdev_gendev.kobj,
+                                 &tape->modes[0].devs[0]->kobj, "tape");
+}
+
+static void remove_cdevs(struct scsi_tape *tape)
+{
+        int mode, rew;
+        sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
+        for (mode = 0; mode < ST_NBR_MODES; mode++) {
+                struct st_modedef *STm = &(tape->modes[mode]);
+                for (rew = 0; rew < 2; rew++) {
+                        if (STm->cdevs[rew])
+                                cdev_del(STm->cdevs[rew]);
+                        if (STm->devs[rew])
+                                device_unregister(STm->devs[rew]);
+                }
+        }
+}
+
 static int st_probe(struct device *dev)
 {
         struct scsi_device *SDp = to_scsi_device(dev);
         struct gendisk *disk = NULL;
-        struct cdev *cdev = NULL;
         struct scsi_tape *tpnt = NULL;
         struct st_modedef *STm;
         struct st_partstat *STps;
         struct st_buffer *buffer;
-        int i, j, mode, dev_num, error;
+        int i, dev_num, error;
         char *stp;
 
         if (SDp->type != TYPE_TAPE)
@@ -4125,36 +4206,10 @@ static int st_probe(struct device *dev)
 
         dev_set_drvdata(dev, tpnt);
 
-        for (mode = 0; mode < ST_NBR_MODES; ++mode) {
-                STm = &(tpnt->modes[mode]);
-                for (j=0; j < 2; j++) {
-                        cdev = cdev_alloc();
-                        if (!cdev) {
-                                printk(KERN_ERR
-                                       "st%d: out of memory. Device not attached.\n",
-                                       dev_num);
-                                cdev_del(cdev);
-                                goto out_free_tape;
-                        }
-                        cdev->owner = THIS_MODULE;
-                        cdev->ops = &st_fops;
-
-                        error = cdev_add(cdev,
-                                         MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, j)),
-                                         1);
-                        if (error) {
-                                printk(KERN_ERR "st%d: Can't add %s-rewind mode %d\n",
-                                       dev_num, j ? "non" : "auto", mode);
-                                printk(KERN_ERR "st%d: Device not attached.\n", dev_num);
-                                goto out_free_tape;
-                        }
-                        STm->cdevs[j] = cdev;
 
-                }
-                error = do_create_class_files(tpnt, dev_num, mode);
-                if (error)
-                        goto out_free_tape;
-        }
+        error = create_cdevs(tpnt);
+        if (error)
+                goto out_remove_devs;
         scsi_autopm_put_device(SDp);
 
         sdev_printk(KERN_NOTICE, SDp,
@@ -4165,20 +4220,8 @@ static int st_probe(struct device *dev)
 
         return 0;
 
-out_free_tape:
-        sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
-                          "tape");
-        for (mode=0; mode < ST_NBR_MODES; mode++) {
-                STm = &(tpnt->modes[mode]);
-                for (j=0; j < 2; j++) {
-                        if (STm->cdevs[j]) {
-                                device_destroy(&st_sysfs_class,
-                                               MKDEV(SCSI_TAPE_MAJOR,
-                                                     TAPE_MINOR(i, mode, j)));
-                                cdev_del(STm->cdevs[j]);
-                        }
-                }
-        }
+out_remove_devs:
+        remove_cdevs(tpnt);
 out_put_index:
         spin_lock(&st_index_lock);
         idr_remove(&st_index_idr, dev_num);
@@ -4196,24 +4239,10 @@ out:
 static int st_remove(struct device *dev)
 {
         struct scsi_tape *tpnt = dev_get_drvdata(dev);
-        int rew, mode;
-        dev_t cdev_devno;
-        struct cdev *cdev;
         int index = tpnt->index;
 
         scsi_autopm_get_device(to_scsi_device(dev));
-        sysfs_remove_link(&tpnt->device->sdev_gendev.kobj, "tape");
-        for (mode = 0; mode < ST_NBR_MODES; ++mode) {
-                for (rew = 0; rew < 2; rew++) {
-                        cdev = tpnt->modes[mode].cdevs[rew];
-                        if (!cdev)
-                                continue;
-                        cdev_devno = cdev->dev;
-                        device_destroy(&st_sysfs_class, cdev_devno);
-                        cdev_del(tpnt->modes[mode].cdevs[rew]);
-                        tpnt->modes[mode].cdevs[rew] = NULL;
-                }
-        }
+        remove_cdevs(tpnt);
 
         mutex_lock(&st_ref_mutex);
         kref_put(&tpnt->kref, scsi_tape_release);
@@ -4462,50 +4491,6 @@ static struct device_attribute st_dev_attrs[] = {
         __ATTR_NULL,
 };
 
-static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
-{
-        int i, rew, error;
-        char name[10];
-        struct device *st_class_member;
-
-        for (rew=0; rew < 2; rew++) {
-                /* Make sure that the minor numbers corresponding to the four
-                   first modes always get the same names */
-                i = mode << (4 - ST_NBR_MODE_BITS);
-                snprintf(name, 10, "%s%s%s", rew ? "n" : "",
-                         STp->disk->disk_name, st_formats[i]);
-                st_class_member =
-                        device_create(&st_sysfs_class,
-                                      &STp->device->sdev_gendev,
-                                      MKDEV(SCSI_TAPE_MAJOR,
-                                            TAPE_MINOR(dev_num, mode, rew)),
-                                      &STp->modes[mode], "%s", name);
-                if (IS_ERR(st_class_member)) {
-                        printk(KERN_WARNING "st%d: device_create failed\n",
-                               dev_num);
-                        error = PTR_ERR(st_class_member);
-                        goto out;
-                }
-
-                if (mode == 0 && rew == 0) {
-                        error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
-                                                  &st_class_member->kobj,
-                                                  "tape");
-                        if (error) {
-                                printk(KERN_ERR
-                                       "st%d: Can't create sysfs link from SCSI device.\n",
-                                       dev_num);
-                                goto out;
-                        }
-                }
-        }
-
-        return 0;
-
-out:
-        return error;
-}
-
 /* The following functions may be useful for a larger audience. */
 static int sgl_map_user_pages(struct st_buffer *STbp,
                               const unsigned int max_pages, unsigned long uaddr,
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index 8a23640981c8..b7a07c7bf4f8 100644
--- a/drivers/scsi/st.h
+++ b/drivers/scsi/st.h
@@ -67,6 +67,7 @@ struct st_modedef {
         short default_density;  /* Forced density, -1 = no value */
         int default_blksize;    /* Forced blocksize, -1 = no value */
         struct scsi_tape *tape;
+        struct device *devs[2];  /* Auto-rewind and non-rewind devices */
         struct cdev *cdevs[2];  /* Auto-rewind and non-rewind devices */
 };