Re: [PATCH 8/8] bdi: remove the name field in struct backing_dev_info

From: Jan Kara
Date: Thu Apr 16 2020 - 08:23:38 EST


On Thu 16-04-20 09:15:19, Christoph Hellwig wrote:
> The name is only printed for a not registered bdi in writeback. Use the
> device name there as is more useful anyway for the unlike case that the
> warning triggers.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Ah, cool. So it isn't used in sysfs/debugfs as I was afraid. The patch
looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> block/blk-core.c | 1 -
> drivers/mtd/mtdcore.c | 1 -
> fs/fs-writeback.c | 2 +-
> fs/super.c | 2 --
> include/linux/backing-dev-defs.h | 2 --
> mm/backing-dev.c | 1 -
> 6 files changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index ab87f2833ab2..f37068c611bf 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -494,7 +494,6 @@ struct request_queue *__blk_alloc_queue(int node_id)
>
> q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES;
> q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
> - q->backing_dev_info->name = "block";
> q->node = node_id;
>
> timer_setup(&q->backing_dev_info->laptop_mode_wb_timer,
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 39ec563d9a14..fcb018ce17c3 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -2040,7 +2040,6 @@ static struct backing_dev_info * __init mtd_bdi_init(char *name)
> if (!bdi)
> return ERR_PTR(-ENOMEM);
>
> - bdi->name = name;
> /*
> * We put '-0' suffix to the name to get the same name format as we
> * used to get. Since this is called only once, we get a unique name.
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index 76ac9c7d32ec..d85323607b49 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -2320,7 +2320,7 @@ void __mark_inode_dirty(struct inode *inode, int flags)
>
> WARN(bdi_cap_writeback_dirty(wb->bdi) &&
> !test_bit(WB_registered, &wb->state),
> - "bdi-%s not registered\n", wb->bdi->name);
> + "bdi-%s not registered\n", bdi_dev_name(wb->bdi));
>
> inode->dirtied_when = jiffies;
> if (dirtytime)
> diff --git a/fs/super.c b/fs/super.c
> index dd28fcd706ff..4991f441988e 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -1602,8 +1602,6 @@ int super_setup_bdi_name(struct super_block *sb, char *fmt, ...)
> if (!bdi)
> return -ENOMEM;
>
> - bdi->name = sb->s_type->name;
> -
> va_start(args, fmt);
> err = bdi_register_va(bdi, fmt, args);
> va_end(args);
> diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
> index 249590bcccf7..0a55170b2142 100644
> --- a/include/linux/backing-dev-defs.h
> +++ b/include/linux/backing-dev-defs.h
> @@ -194,8 +194,6 @@ struct backing_dev_info {
> congested_fn *congested_fn; /* Function pointer if device is md/dm */
> void *congested_data; /* Pointer to aux data for congested func */
>
> - const char *name;
> -
> struct kref refcnt; /* Reference counter for the structure */
> unsigned int capabilities; /* Device capabilities */
> unsigned int min_ratio;
> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index 119a41650833..dc7215dfd56b 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -15,7 +15,6 @@
> #include <trace/events/writeback.h>
>
> struct backing_dev_info noop_backing_dev_info = {
> - .name = "noop",
> .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
> };
> EXPORT_SYMBOL_GPL(noop_backing_dev_info);
> --
> 2.25.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR