Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...
[platform/kernel/linux-rpi.git] / fs / block_dev.c
index e215da6..7e83c3e 100644 (file)
@@ -895,7 +895,6 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
        mapping_set_gfp_mask(&inode->i_data, GFP_USER);
 
        bdev = I_BDEV(inode);
-       mutex_init(&bdev->bd_mutex);
        mutex_init(&bdev->bd_fsfreeze_mutex);
        spin_lock_init(&bdev->bd_size_lock);
        bdev->bd_disk = disk;
@@ -1154,7 +1153,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
        struct bd_holder_disk *holder;
        int ret = 0;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->open_mutex);
 
        WARN_ON_ONCE(!bdev->bd_holder);
 
@@ -1199,7 +1198,7 @@ out_del:
 out_free:
        kfree(holder);
 out_unlock:
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->open_mutex);
        return ret;
 }
 EXPORT_SYMBOL_GPL(bd_link_disk_holder);
@@ -1218,7 +1217,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
 {
        struct bd_holder_disk *holder;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->open_mutex);
 
        holder = bd_find_holder_disk(bdev, disk);
 
@@ -1230,138 +1229,97 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
                kfree(holder);
        }
 
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->open_mutex);
 }
 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
 #endif
 
-static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
+static void blkdev_flush_mapping(struct block_device *bdev)
+{
+       WARN_ON_ONCE(bdev->bd_holders);
+       sync_blockdev(bdev);
+       kill_bdev(bdev);
+       bdev_write_inode(bdev);
+}
 
-int bdev_disk_changed(struct block_device *bdev, bool invalidate)
+static int blkdev_get_whole(struct block_device *bdev, fmode_t mode)
 {
        struct gendisk *disk = bdev->bd_disk;
        int ret = 0;
 
-       lockdep_assert_held(&bdev->bd_mutex);
-
-       if (!(disk->flags & GENHD_FL_UP))
-               return -ENXIO;
-
-rescan:
-       if (bdev->bd_part_count)
-               return -EBUSY;
-       sync_blockdev(bdev);
-       invalidate_bdev(bdev);
-       blk_drop_partitions(disk);
-
-       clear_bit(GD_NEED_PART_SCAN, &disk->state);
-
-       /*
-        * Historically we only set the capacity to zero for devices that
-        * support partitions (independ of actually having partitions created).
-        * Doing that is rather inconsistent, but changing it broke legacy
-        * udisks polling for legacy ide-cdrom devices.  Use the crude check
-        * below to get the sane behavior for most device while not breaking
-        * userspace for this particular setup.
-        */
-       if (invalidate) {
-               if (disk_part_scan_enabled(disk) ||
-                   !(disk->flags & GENHD_FL_REMOVABLE))
-                       set_capacity(disk, 0);
+       if (disk->fops->open) {
+               ret = disk->fops->open(bdev, mode);
+               if (ret) {
+                       /* avoid ghost partitions on a removed medium */
+                       if (ret == -ENOMEDIUM &&
+                            test_bit(GD_NEED_PART_SCAN, &disk->state))
+                               bdev_disk_changed(disk, true);
+                       return ret;
+               }
        }
 
-       if (get_capacity(disk)) {
-               ret = blk_add_partitions(disk, bdev);
-               if (ret == -EAGAIN)
-                       goto rescan;
-       } else if (invalidate) {
-               /*
-                * Tell userspace that the media / partition table may have
-                * changed.
-                */
-               kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+       if (!bdev->bd_openers) {
+               set_init_blocksize(bdev);
+               if (bdev->bd_bdi == &noop_backing_dev_info)
+                       bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
        }
+       if (test_bit(GD_NEED_PART_SCAN, &disk->state))
+               bdev_disk_changed(disk, false);
+       bdev->bd_openers++;
+       return 0;;
+}
 
-       return ret;
+static void blkdev_put_whole(struct block_device *bdev, fmode_t mode)
+{
+       if (!--bdev->bd_openers)
+               blkdev_flush_mapping(bdev);
+       if (bdev->bd_disk->fops->release)
+               bdev->bd_disk->fops->release(bdev->bd_disk, mode);
 }
-/*
- * Only exported for loop and dasd for historic reasons.  Don't use in new
- * code!
- */
-EXPORT_SYMBOL_GPL(bdev_disk_changed);
 
-/*
- * bd_mutex locking:
- *
- *  mutex_lock(part->bd_mutex)
- *    mutex_lock_nested(whole->bd_mutex, 1)
- */
-static int __blkdev_get(struct block_device *bdev, fmode_t mode)
+static int blkdev_get_part(struct block_device *part, fmode_t mode)
 {
-       struct gendisk *disk = bdev->bd_disk;
-       int ret = 0;
+       struct gendisk *disk = part->bd_disk;
+       struct block_device *whole;
+       int ret;
 
-       if (!(disk->flags & GENHD_FL_UP))
-               return -ENXIO;
+       if (part->bd_openers)
+               goto done;
 
-       if (!bdev->bd_openers) {
-               if (!bdev_is_partition(bdev)) {
-                       ret = 0;
-                       if (disk->fops->open)
-                               ret = disk->fops->open(bdev, mode);
+       whole = bdgrab(disk->part0);
+       ret = blkdev_get_whole(whole, mode);
+       if (ret)
+               goto out_put_whole;
 
-                       if (!ret)
-                               set_init_blocksize(bdev);
+       ret = -ENXIO;
+       if (!bdev_nr_sectors(part))
+               goto out_blkdev_put;
 
-                       /*
-                        * If the device is invalidated, rescan partition
-                        * if open succeeded or failed with -ENOMEDIUM.
-                        * The latter is necessary to prevent ghost
-                        * partitions on a removed medium.
-                        */
-                       if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
-                           (!ret || ret == -ENOMEDIUM))
-                               bdev_disk_changed(bdev, ret == -ENOMEDIUM);
+       disk->open_partitions++;
+       set_init_blocksize(part);
+       if (part->bd_bdi == &noop_backing_dev_info)
+               part->bd_bdi = bdi_get(disk->queue->backing_dev_info);
+done:
+       part->bd_openers++;
+       return 0;
 
-                       if (ret)
-                               return ret;
-               } else {
-                       struct block_device *whole = bdgrab(disk->part0);
-
-                       mutex_lock_nested(&whole->bd_mutex, 1);
-                       ret = __blkdev_get(whole, mode);
-                       if (ret) {
-                               mutex_unlock(&whole->bd_mutex);
-                               bdput(whole);
-                               return ret;
-                       }
-                       whole->bd_part_count++;
-                       mutex_unlock(&whole->bd_mutex);
+out_blkdev_put:
+       blkdev_put_whole(whole, mode);
+out_put_whole:
+       bdput(whole);
+       return ret;
+}
 
-                       if (!bdev_nr_sectors(bdev)) {
-                               __blkdev_put(whole, mode, 1);
-                               bdput(whole);
-                               return -ENXIO;
-                       }
-                       set_init_blocksize(bdev);
-               }
+static void blkdev_put_part(struct block_device *part, fmode_t mode)
+{
+       struct block_device *whole = bdev_whole(part);
 
-               if (bdev->bd_bdi == &noop_backing_dev_info)
-                       bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
-       } else {
-               if (!bdev_is_partition(bdev)) {
-                       if (bdev->bd_disk->fops->open)
-                               ret = bdev->bd_disk->fops->open(bdev, mode);
-                       /* the same as first opener case, read comment there */
-                       if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
-                           (!ret || ret == -ENOMEDIUM))
-                               bdev_disk_changed(bdev, ret == -ENOMEDIUM);
-                       if (ret)
-                               return ret;
-               }
-       }
-       bdev->bd_openers++;
-       return 0;
+       if (--part->bd_openers)
+               return;
+       blkdev_flush_mapping(part);
+       whole->bd_disk->open_partitions--;
+       blkdev_put_whole(whole, mode);
+       bdput(whole);
 }
 
 struct block_device *blkdev_get_no_open(dev_t dev)
@@ -1447,8 +1405,14 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
 
        disk_block_events(disk);
 
-       mutex_lock(&bdev->bd_mutex);
-       ret =__blkdev_get(bdev, mode);
+       mutex_lock(&disk->open_mutex);
+       ret = -ENXIO;
+       if (!(disk->flags & GENHD_FL_UP))
+               goto abort_claiming;
+       if (bdev_is_partition(bdev))
+               ret = blkdev_get_part(bdev, mode);
+       else
+               ret = blkdev_get_whole(bdev, mode);
        if (ret)
                goto abort_claiming;
        if (mode & FMODE_EXCL) {
@@ -1467,7 +1431,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
                        unblock_events = false;
                }
        }
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&disk->open_mutex);
 
        if (unblock_events)
                disk_unblock_events(disk);
@@ -1476,7 +1440,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
 abort_claiming:
        if (mode & FMODE_EXCL)
                bd_abort_claiming(bdev, holder);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&disk->open_mutex);
        disk_unblock_events(disk);
 put_blkdev:
        blkdev_put_no_open(bdev);
@@ -1551,10 +1515,9 @@ static int blkdev_open(struct inode * inode, struct file * filp)
        return 0;
 }
 
-static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
+void blkdev_put(struct block_device *bdev, fmode_t mode)
 {
        struct gendisk *disk = bdev->bd_disk;
-       struct block_device *victim = NULL;
 
        /*
         * Sync early if it looks like we're the last one.  If someone else
@@ -1566,41 +1529,14 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
        if (bdev->bd_openers == 1)
                sync_blockdev(bdev);
 
-       mutex_lock_nested(&bdev->bd_mutex, for_part);
-       if (for_part)
-               bdev->bd_part_count--;
-
-       if (!--bdev->bd_openers) {
-               WARN_ON_ONCE(bdev->bd_holders);
-               sync_blockdev(bdev);
-               kill_bdev(bdev);
-               bdev_write_inode(bdev);
-               if (bdev_is_partition(bdev))
-                       victim = bdev_whole(bdev);
-       }
-
-       if (!bdev_is_partition(bdev) && disk->fops->release)
-               disk->fops->release(disk, mode);
-       mutex_unlock(&bdev->bd_mutex);
-       if (victim) {
-               __blkdev_put(victim, mode, 1);
-               bdput(victim);
-       }
-}
-
-void blkdev_put(struct block_device *bdev, fmode_t mode)
-{
-       struct gendisk *disk = bdev->bd_disk;
-
-       mutex_lock(&bdev->bd_mutex);
-
+       mutex_lock(&disk->open_mutex);
        if (mode & FMODE_EXCL) {
                struct block_device *whole = bdev_whole(bdev);
                bool bdev_free;
 
                /*
                 * Release a claim on the device.  The holder fields
-                * are protected with bdev_lock.  bd_mutex is to
+                * are protected with bdev_lock.  open_mutex is to
                 * synchronize disk_holder unlinking.
                 */
                spin_lock(&bdev_lock);
@@ -1631,9 +1567,13 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
         * from userland - e.g. eject(1).
         */
        disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE);
-       mutex_unlock(&bdev->bd_mutex);
 
-       __blkdev_put(bdev, mode, 0);
+       if (bdev_is_partition(bdev))
+               blkdev_put_part(bdev, mode);
+       else
+               blkdev_put_whole(bdev, mode);
+       mutex_unlock(&disk->open_mutex);
+
        blkdev_put_no_open(bdev);
 }
 EXPORT_SYMBOL(blkdev_put);
@@ -1740,6 +1680,7 @@ static int blkdev_writepages(struct address_space *mapping,
 }
 
 static const struct address_space_operations def_blk_aops = {
+       .set_page_dirty = __set_page_dirty_buffers,
        .readpage       = blkdev_readpage,
        .readahead      = blkdev_readahead,
        .writepage      = blkdev_writepage,
@@ -1925,10 +1866,10 @@ void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
                old_inode = inode;
                bdev = I_BDEV(inode);
 
-               mutex_lock(&bdev->bd_mutex);
+               mutex_lock(&bdev->bd_disk->open_mutex);
                if (bdev->bd_openers)
                        func(bdev, arg);
-               mutex_unlock(&bdev->bd_mutex);
+               mutex_unlock(&bdev->bd_disk->open_mutex);
 
                spin_lock(&blockdev_superblock->s_inode_list_lock);
        }