From 0dbcfe247f22a6d73302dfa691c48b3c14d31c4c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 4 Aug 2021 11:41:42 +0200 Subject: [PATCH] block: look up holders by bdev Invert they way the holder relations are tracked. This very slightly reduces the memory overhead for partitioned devices. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210804094147.459763-4-hch@lst.de Signed-off-by: Jens Axboe --- block/genhd.c | 4 +++- block/holder.c | 18 +++++++++--------- fs/block_dev.c | 3 --- include/linux/blk_types.h | 3 --- include/linux/genhd.h | 4 +++- 5 files changed, 15 insertions(+), 17 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index a4817e4..cd4eab7 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1289,7 +1289,9 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) disk_to_dev(disk)->type = &disk_type; device_initialize(disk_to_dev(disk)); inc_diskseq(disk); - +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED + INIT_LIST_HEAD(&disk->slave_bdevs); +#endif return disk; out_destroy_part_tbl: diff --git a/block/holder.c b/block/holder.c index 960654a..11e65d9 100644 --- a/block/holder.c +++ b/block/holder.c @@ -3,7 +3,7 @@ struct bd_holder_disk { struct list_head list; - struct gendisk *disk; + struct block_device *bdev; int refcnt; }; @@ -12,8 +12,8 @@ static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, { struct bd_holder_disk *holder; - list_for_each_entry(holder, &bdev->bd_holder_disks, list) - if (holder->disk == disk) + list_for_each_entry(holder, &disk->slave_bdevs, list) + if (holder->bdev == bdev) return holder; return NULL; } @@ -61,7 +61,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) struct bd_holder_disk *holder; int ret = 0; - mutex_lock(&bdev->bd_disk->open_mutex); + mutex_lock(&disk->open_mutex); WARN_ON_ONCE(!bdev->bd_holder); @@ -82,7 +82,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) } INIT_LIST_HEAD(&holder->list); - holder->disk = disk; + holder->bdev = bdev; holder->refcnt = 1; ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); @@ -93,7 +93,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) if (ret) goto out_del; - list_add(&holder->list, &bdev->bd_holder_disks); + list_add(&holder->list, &disk->slave_bdevs); goto out_unlock; out_del: @@ -101,7 +101,7 @@ out_del: out_free: kfree(holder); out_unlock: - mutex_unlock(&bdev->bd_disk->open_mutex); + mutex_unlock(&disk->open_mutex); return ret; } EXPORT_SYMBOL_GPL(bd_link_disk_holder); @@ -120,7 +120,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) { struct bd_holder_disk *holder; - mutex_lock(&bdev->bd_disk->open_mutex); + mutex_lock(&disk->open_mutex); holder = bd_find_holder_disk(bdev, disk); if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { del_symlink(disk->slave_dir, bdev_kobj(bdev)); @@ -128,6 +128,6 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) list_del_init(&holder->list); kfree(holder); } - mutex_unlock(&bdev->bd_disk->open_mutex); + mutex_unlock(&disk->open_mutex); } EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); diff --git a/fs/block_dev.c b/fs/block_dev.c index ae9651c..cc80176 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -902,9 +902,6 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) bdev->bd_disk = disk; bdev->bd_partno = partno; bdev->bd_inode = inode; -#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED - INIT_LIST_HEAD(&bdev->bd_holder_disks); -#endif bdev->bd_stats = alloc_percpu(struct disk_stats); if (!bdev->bd_stats) { iput(inode); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 7a4e139..e927356 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -34,9 +34,6 @@ struct block_device { void * bd_holder; int bd_holders; bool bd_write_holder; -#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED - struct list_head bd_holder_disks; -#endif struct kobject *bd_holder_dir; u8 bd_partno; spinlock_t bd_size_lock; /* for bd_inode->i_size updates */ diff --git a/include/linux/genhd.h b/include/linux/genhd.h index e21a91c..0721807 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -159,7 +159,9 @@ struct gendisk { unsigned open_partitions; /* number of open partitions */ struct kobject *slave_dir; - +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED + struct list_head slave_bdevs; +#endif struct timer_rand_state *random; atomic_t sync_io; /* RAID */ struct disk_events *ev; -- 2.7.4