block: implement and use {disk|part}_to_dev()

Implement {disk|part}_to_dev() and use them to access generic device
instead of directly dereferencing {disk|part}->dev.  To make sure no
user is left behind, rename generic devices fields to __dev.

This is in preparation of unifying partition 0 handling with other
partitions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

11 files changed, 86 insertions, 77 deletions

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index d87606eaca1d..69023da63151 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -331,7 +331,8 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
                         return -1;
 
                 if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
-                                         &disk->dev.kobj, "%s", "integrity")) {
+                                         &disk_to_dev(disk)->kobj,
+                                         "%s", "integrity")) {
                         kmem_cache_free(integrity_cachep, bi);
                         return -1;
                 }
@@ -375,7 +376,7 @@ void blk_integrity_unregister(struct gendisk *disk)
 
         kobject_uevent(&bi->kobj, KOBJ_REMOVE);
         kobject_del(&bi->kobj);
-        kobject_put(&disk->dev.kobj);
+        kobject_put(&disk_to_dev(disk)->kobj);
         kmem_cache_free(integrity_cachep, bi);
 }
 EXPORT_SYMBOL(blk_integrity_unregister);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 304ec73ab821..b9a6ed166649 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -310,7 +310,7 @@ int blk_register_queue(struct gendisk *disk)
         if (!q->request_fn)
                 return 0;
 
-        ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
+        ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj),
                           "%s", "queue");
         if (ret < 0)
                 return ret;
@@ -339,6 +339,6 @@ void blk_unregister_queue(struct gendisk *disk)
 
                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
                 kobject_del(&q->kobj);
-                kobject_put(&disk->dev.kobj);
+                kobject_put(&disk_to_dev(disk)->kobj);
         }
 }
diff --git a/block/genhd.c b/block/genhd.c
index 67e5a59ced2a..0a2f16bd54b7 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -59,7 +59,7 @@ struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
         rcu_read_lock();
         part = rcu_dereference(disk->__part[partno - 1]);
         if (part)
-                get_device(&part->dev);
+                get_device(part_to_dev(part));
         rcu_read_unlock();
 
         return part;
@@ -130,7 +130,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
                 if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects)
                         continue;
 
-                get_device(&part->dev);
+                get_device(part_to_dev(part));
                 piter->part = part;
                 piter->idx += inc;
                 break;
@@ -435,7 +435,7 @@ static struct kobject *exact_match(dev_t devt, int *partno, void *data)
 {
         struct gendisk *p = data;
 
-        return &p->dev.kobj;
+        return &disk_to_dev(p)->kobj;
 }
 
 static int exact_lock(dev_t devt, void *data)
@@ -460,7 +460,7 @@ void add_disk(struct gendisk *disk)
         int retval;
 
         disk->flags |= GENHD_FL_UP;
-        disk->dev.devt = MKDEV(disk->major, disk->first_minor);
+        disk_to_dev(disk)->devt = MKDEV(disk->major, disk->first_minor);
         blk_register_region(disk_devt(disk), disk->minors, NULL,
                             exact_match, exact_lock, disk);
         register_disk(disk);
@@ -468,7 +468,8 @@ void add_disk(struct gendisk *disk)
 
         bdi = &disk->queue->backing_dev_info;
         bdi_register_dev(bdi, disk_devt(disk));
-        retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
+        retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
+                                   "bdi");
         WARN_ON(retval);
 }
 
@@ -477,7 +478,7 @@ EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
 
 void unlink_gendisk(struct gendisk *disk)
 {
-        sysfs_remove_link(&disk->dev.kobj, "bdi");
+        sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
         bdi_unregister(&disk->queue->backing_dev_info);
         blk_unregister_queue(disk);
         blk_unregister_region(disk_devt(disk), disk->minors);
@@ -903,7 +904,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
         int cpu;
 
         /*
-        if (&gp->dev.kobj.entry == block_class.devices.next)
+        if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
                 seq_puts(seqf,  "major minor name"
                                 "     rio rmerge rsect ruse wio wmerge "
                                 "wsect wuse running use aveq"
@@ -972,7 +973,7 @@ static void media_change_notify_thread(struct work_struct *work)
          * set enviroment vars to indicate which event this is for
          * so that user space will know to go check the media status.
          */
-        kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
+        kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
         put_device(gd->driverfs_dev);
 }
 
@@ -1062,9 +1063,9 @@ struct gendisk *alloc_disk_ext_node(int minors, int ext_minors, int node_id)
                 disk->minors = minors;
                 disk->ext_minors = ext_minors;
                 rand_initialize_disk(disk);
-                disk->dev.class = &block_class;
-                disk->dev.type = &disk_type;
-                device_initialize(&disk->dev);
+                disk_to_dev(disk)->class = &block_class;
+                disk_to_dev(disk)->type = &disk_type;
+                device_initialize(disk_to_dev(disk));
                 INIT_WORK(&disk->async_notify,
                         media_change_notify_thread);
         }
@@ -1086,7 +1087,7 @@ struct kobject *get_disk(struct gendisk *disk)
         owner = disk->fops->owner;
         if (owner && !try_module_get(owner))
                 return NULL;
-        kobj = kobject_get(&disk->dev.kobj);
+        kobj = kobject_get(&disk_to_dev(disk)->kobj);
         if (kobj == NULL) {
                 module_put(owner);
                 return NULL;
@@ -1100,7 +1101,7 @@ EXPORT_SYMBOL(get_disk);
 void put_disk(struct gendisk *disk)
 {
         if (disk)
-                kobject_put(&disk->dev.kobj);
+                kobject_put(&disk_to_dev(disk)->kobj);
 }
 
 EXPORT_SYMBOL(put_disk);
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 0c39782b2660..3edb6cb7d68f 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -109,12 +109,12 @@ static const struct attribute_group attr_group = {
 static int
 aoedisk_add_sysfs(struct aoedev *d)
 {
-        return sysfs_create_group(&d->gd->dev.kobj, &attr_group);
+        return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 }
 void
 aoedisk_rm_sysfs(struct aoedev *d)
 {
-        sysfs_remove_group(&d->gd->dev.kobj, &attr_group);
+        sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 }
 
 static int
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 1778e4a2c672..7b3351260d56 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -403,7 +403,7 @@ static int nbd_do_it(struct nbd_device *lo)
         BUG_ON(lo->magic != LO_MAGIC);
 
         lo->pid = current->pid;
-        ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr);
+        ret = sysfs_create_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
         if (ret) {
                 printk(KERN_ERR "nbd: sysfs_create_file failed!");
                 return ret;
@@ -412,7 +412,7 @@ static int nbd_do_it(struct nbd_device *lo)
         while ((req = nbd_read_stat(lo)) != NULL)
                 nbd_end_request(req);
 
-        sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr);
+        sysfs_remove_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
         return 0;
 }
 
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index a51a30e9eab3..70aa86c8807e 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1188,7 +1188,7 @@ static struct kobject *exact_match(dev_t dev, int *part, void *data)
 {
         struct gendisk *p = data;
         *part &= (1 << PARTN_BITS) - 1;
-        return &p->dev.kobj;
+        return &disk_to_dev(p)->kobj;
 }
 
 static int exact_lock(dev_t dev, void *data)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 653624792eaf..637806695bb9 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1186,7 +1186,7 @@ static void event_callback(void *context)
         list_splice_init(&md->uevent_list, &uevents);
         spin_unlock_irqrestore(&md->uevent_lock, flags);
 
-        dm_send_uevents(&uevents, &md->disk->dev.kobj);
+        dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
 
         atomic_inc(&md->event_nr);
         wake_up(&md->eventq);
@@ -1643,7 +1643,7 @@ out:
  *---------------------------------------------------------------*/
 void dm_kobject_uevent(struct mapped_device *md)
 {
-        kobject_uevent(&md->disk->dev.kobj, KOBJ_CHANGE);
+        kobject_uevent(&disk_to_dev(md->disk)->kobj, KOBJ_CHANGE);
 }
 
 uint32_t dm_next_uevent_seq(struct mapped_device *md)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index deeac4b44173..96e9fccd2eab 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1465,9 +1465,9 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
                 goto fail;
 
         if (rdev->bdev->bd_part)
-                ko = &rdev->bdev->bd_part->dev.kobj;
+                ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
         else
-                ko = &rdev->bdev->bd_disk->dev.kobj;
+                ko = &disk_to_dev(rdev->bdev->bd_disk)->kobj;
         if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
                 kobject_del(&rdev->kobj);
                 goto fail;
@@ -3470,8 +3470,8 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
         disk->queue = mddev->queue;
         add_disk(disk);
         mddev->gendisk = disk;
-        error = kobject_init_and_add(&mddev->kobj, &md_ktype, &disk->dev.kobj,
-                                     "%s", "md");
+        error = kobject_init_and_add(&mddev->kobj, &md_ktype,
+                                     &disk_to_dev(disk)->kobj, "%s", "md");
         mutex_unlock(&disks_mutex);
         if (error)
                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
@@ -3761,7 +3761,7 @@ static int do_md_run(mddev_t * mddev)
         sysfs_notify(&mddev->kobj, NULL, "array_state");
         sysfs_notify(&mddev->kobj, NULL, "sync_action");
         sysfs_notify(&mddev->kobj, NULL, "degraded");
-        kobject_uevent(&mddev->gendisk->dev.kobj, KOBJ_CHANGE);
+        kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
         return 0;
 }
 
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 2f2873b9a041..a02df22f37c3 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -543,9 +543,9 @@ EXPORT_SYMBOL(bd_release);
 static struct kobject *bdev_get_kobj(struct block_device *bdev)
 {
         if (bdev->bd_contains != bdev)
-                return kobject_get(&bdev->bd_part->dev.kobj);
+                return kobject_get(&part_to_dev(bdev->bd_part)->kobj);
         else
-                return kobject_get(&bdev->bd_disk->dev.kobj);
+                return kobject_get(&disk_to_dev(bdev->bd_disk)->kobj);
 }
 
 static struct kobject *bdev_get_holder(struct block_device *bdev)
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 0d4b7f28f13f..ac0df3acdcda 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -309,7 +309,7 @@ static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 {
         struct kobject *k;
 
-        k = kobject_get(&disk->dev.kobj);
+        k = kobject_get(&disk_to_dev(disk)->kobj);
         disk->holder_dir = kobject_create_and_add("holders", k);
         disk->slave_dir = kobject_create_and_add("slaves", k);
         kobject_put(k);
@@ -322,7 +322,7 @@ static void delete_partition_rcu_cb(struct rcu_head *head)
         part->start_sect = 0;
         part->nr_sects = 0;
         part_stat_set_all(part, 0);
-        put_device(&part->dev);
+        put_device(part_to_dev(part));
 }
 
 void delete_partition(struct gendisk *disk, int partno)
@@ -336,7 +336,7 @@ void delete_partition(struct gendisk *disk, int partno)
         blk_free_devt(part_devt(part));
         rcu_assign_pointer(disk->__part[partno-1], NULL);
         kobject_put(part->holder_dir);
-        device_del(&part->dev);
+        device_del(part_to_dev(part));
 
         call_rcu(&part->rcu_head, delete_partition_rcu_cb);
 }
@@ -354,6 +354,9 @@ int add_partition(struct gendisk *disk, int partno,
 {
         struct hd_struct *p;
         dev_t devt = MKDEV(0, 0);
+        struct device *ddev = disk_to_dev(disk);
+        struct device *pdev;
+        const char *dname;
         int err;
 
         if (disk->__part[partno - 1])
@@ -367,42 +370,43 @@ int add_partition(struct gendisk *disk, int partno,
                 err = -ENOMEM;
                 goto out_free;
         }
+        pdev = part_to_dev(p);
+
         p->start_sect = start;
         p->nr_sects = len;
         p->partno = partno;
         p->policy = disk->policy;
 
-        if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
-                snprintf(p->dev.bus_id, BUS_ID_SIZE,
-                "%sp%d", disk->dev.bus_id, partno);
+        dname = dev_name(ddev);
+        if (isdigit(dname[strlen(dname) - 1]))
+                snprintf(pdev->bus_id, BUS_ID_SIZE, "%sp%d", dname, partno);
         else
-                snprintf(p->dev.bus_id, BUS_ID_SIZE,
-                         "%s%d", disk->dev.bus_id, partno);
+                snprintf(pdev->bus_id, BUS_ID_SIZE, "%s%d", dname, partno);
 
-        device_initialize(&p->dev);
-        p->dev.class = &block_class;
-        p->dev.type = &part_type;
-        p->dev.parent = &disk->dev;
+        device_initialize(pdev);
+        pdev->class = &block_class;
+        pdev->type = &part_type;
+        pdev->parent = ddev;
 
         err = blk_alloc_devt(p, &devt);
         if (err)
-                goto out_put;
-        p->dev.devt = devt;
+                goto out_free;
+        pdev->devt = devt;
 
         /* delay uevent until 'holders' subdir is created */
-        p->dev.uevent_suppress = 1;
-        err = device_add(&p->dev);
+        pdev->uevent_suppress = 1;
+        err = device_add(pdev);
         if (err)
                 goto out_put;
 
         err = -ENOMEM;
-        p->holder_dir = kobject_create_and_add("holders", &p->dev.kobj);
+        p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
         if (!p->holder_dir)
                 goto out_del;
 
-        p->dev.uevent_suppress = 0;
+        pdev->uevent_suppress = 0;
         if (flags & ADDPART_FLAG_WHOLEDISK) {
-                err = device_create_file(&p->dev, &dev_attr_whole_disk);
+                err = device_create_file(pdev, &dev_attr_whole_disk);
                 if (err)
                         goto out_del;
         }
@@ -412,8 +416,8 @@ int add_partition(struct gendisk *disk, int partno,
         rcu_assign_pointer(disk->__part[partno - 1], p);
 
         /* suppress uevent if the disk supresses it */
-        if (!disk->dev.uevent_suppress)
-                kobject_uevent(&p->dev.kobj, KOBJ_ADD);
+        if (!ddev->uevent_suppress)
+                kobject_uevent(&pdev->kobj, KOBJ_ADD);
 
         return 0;
 
@@ -422,9 +426,9 @@ out_free:
         return err;
 out_del:
         kobject_put(p->holder_dir);
-        device_del(&p->dev);
+        device_del(pdev);
 out_put:
-        put_device(&p->dev);
+        put_device(pdev);
         blk_free_devt(devt);
         return err;
 }
@@ -432,30 +436,31 @@ out_put:
 /* Not exported, helper to add_disk(). */
 void register_disk(struct gendisk *disk)
 {
+        struct device *ddev = disk_to_dev(disk);
         struct block_device *bdev;
         struct disk_part_iter piter;
         struct hd_struct *part;
         char *s;
         int err;
 
-        disk->dev.parent = disk->driverfs_dev;
+        ddev->parent = disk->driverfs_dev;
 
-        strlcpy(disk->dev.bus_id, disk->disk_name, BUS_ID_SIZE);
+        strlcpy(ddev->bus_id, disk->disk_name, BUS_ID_SIZE);
         /* ewww... some of these buggers have / in the name... */
-        s = strchr(disk->dev.bus_id, '/');
+        s = strchr(ddev->bus_id, '/');
         if (s)
                 *s = '!';
 
         /* delay uevents, until we scanned partition table */
-        disk->dev.uevent_suppress = 1;
+        ddev->uevent_suppress = 1;
 
-        if (device_add(&disk->dev))
+        if (device_add(ddev))
                 return;
 #ifndef CONFIG_SYSFS_DEPRECATED
-        err = sysfs_create_link(block_depr, &disk->dev.kobj,
-                                kobject_name(&disk->dev.kobj));
+        err = sysfs_create_link(block_depr, &ddev->kobj,
+                                kobject_name(&ddev->kobj));
         if (err) {
-                device_del(&disk->dev);
+                device_del(ddev);
                 return;
         }
 #endif
@@ -481,13 +486,13 @@ void register_disk(struct gendisk *disk)
 
 exit:
         /* announce disk after possible partitions are created */
-        disk->dev.uevent_suppress = 0;
-        kobject_uevent(&disk->dev.kobj, KOBJ_ADD);
+        ddev->uevent_suppress = 0;
+        kobject_uevent(&ddev->kobj, KOBJ_ADD);
 
         /* announce possible partitions */
         disk_part_iter_init(&piter, disk, 0);
         while ((part = disk_part_iter_next(&piter)))
-                kobject_uevent(&part->dev.kobj, KOBJ_ADD);
+                kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
         disk_part_iter_exit(&piter);
 }
 
@@ -518,7 +523,7 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
                 return -EIO;
 
         /* tell userspace that the media / partition table may have changed */
-        kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);
+        kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 
         for (p = 1; p < state->limit; p++) {
                 sector_t size = state->parts[p].size;
@@ -591,7 +596,7 @@ void del_gendisk(struct gendisk *disk)
         kobject_put(disk->slave_dir);
         disk->driverfs_dev = NULL;
 #ifndef CONFIG_SYSFS_DEPRECATED
-        sysfs_remove_link(block_depr, disk->dev.bus_id);
+        sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 #endif
-        device_del(&disk->dev);
+        device_del(disk_to_dev(disk));
 }
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 6fc532424062..e4e18c509ac5 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -15,9 +15,11 @@
 
 #ifdef CONFIG_BLOCK
 
-#define kobj_to_dev(k) container_of(k, struct device, kobj)
-#define dev_to_disk(device) container_of(device, struct gendisk, dev)
-#define dev_to_part(device) container_of(device, struct hd_struct, dev)
+#define kobj_to_dev(k)          container_of((k), struct device, kobj)
+#define dev_to_disk(device)     container_of((device), struct gendisk, __dev)
+#define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
+#define disk_to_dev(disk)       (&((disk)->__dev))
+#define part_to_dev(part)       (&((part)->__dev))
 
 extern struct device_type part_type;
 extern struct kobject *block_depr;
@@ -88,7 +90,7 @@ struct disk_stats {
 struct hd_struct {
         sector_t start_sect;
         sector_t nr_sects;
-        struct device dev;
+        struct device __dev;
         struct kobject *holder_dir;
         int policy, partno;
 #ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -139,7 +141,7 @@ struct gendisk {
 
         int flags;
         struct device *driverfs_dev;  // FIXME: remove
-        struct device dev;
+        struct device __dev;
         struct kobject *holder_dir;
         struct kobject *slave_dir;
 
@@ -163,7 +165,7 @@ struct gendisk {
 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 {
         if (likely(part))
-                return dev_to_disk((part)->dev.parent);
+                return dev_to_disk(part_to_dev(part)->parent);
         return NULL;
 }
 
@@ -174,12 +176,12 @@ static inline int disk_max_parts(struct gendisk *disk)
 
 static inline dev_t disk_devt(struct gendisk *disk)
 {
-        return disk->dev.devt;
+        return disk_to_dev(disk)->devt;
 }
 
 static inline dev_t part_devt(struct hd_struct *part)
 {
-        return part->dev.devt;
+        return part_to_dev(part)->devt;
 }
 
 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
@@ -187,7 +189,7 @@ extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 static inline void disk_put_part(struct hd_struct *part)
 {
         if (likely(part))
-                put_device(&part->dev);
+                put_device(part_to_dev(part));
 }
 
 /*