bdi: remove the name field in struct backing_dev_info

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: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -511,7 +511,6 @@ 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,

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. 

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)

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);

include/linux/backing-dev-defs.h

@@ -193,8 +193,6 @@ 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;

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);