block: move bd_mutex to struct gendisk
Replace the per-block device bd_mutex with a per-gendisk open_mutex,
thus simplifying locking wherever we deal with partitions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 41d2d97..e094806 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -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 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
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);
@@ -1230,7 +1229,7 @@ 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
@@ -1242,7 +1241,7 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate)
struct gendisk *disk = bdev->bd_disk;
int ret = 0;
- lockdep_assert_held(&bdev->bd_mutex);
+ lockdep_assert_held(&disk->open_mutex);
if (!(disk->flags & GENHD_FL_UP))
return -ENXIO;
@@ -1327,14 +1326,10 @@ static int blkdev_get_part(struct block_device *part, fmode_t mode)
goto done;
whole = bdgrab(disk->part0);
- mutex_lock_nested(&whole->bd_mutex, 1);
ret = blkdev_get_whole(whole, mode);
- if (ret) {
- mutex_unlock(&whole->bd_mutex);
+ if (ret)
goto out_put_whole;
- }
whole->bd_part_count++;
- mutex_unlock(&whole->bd_mutex);
ret = -ENXIO;
if (!bdev_nr_sectors(part))
@@ -1437,7 +1432,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
disk_block_events(disk);
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock(&disk->open_mutex);
ret = -ENXIO;
if (!(disk->flags & GENHD_FL_UP))
goto abort_claiming;
@@ -1463,7 +1458,7 @@ 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);
@@ -1472,7 +1467,7 @@ 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);
@@ -1552,7 +1547,6 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
struct gendisk *disk = bdev->bd_disk;
struct block_device *victim = NULL;
- mutex_lock_nested(&bdev->bd_mutex, for_part);
if (for_part)
bdev->bd_part_count--;
@@ -1567,7 +1561,6 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
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);
@@ -1588,15 +1581,14 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
if (bdev->bd_openers == 1)
sync_blockdev(bdev);
- 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);
@@ -1627,9 +1619,10 @@ 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);
+ mutex_unlock(&disk->open_mutex);
+
blkdev_put_no_open(bdev);
}
EXPORT_SYMBOL(blkdev_put);
@@ -1936,10 +1929,10 @@ 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);
}