Commit fa06052d authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe
Browse files

mtd: Convert to dynamically allocated bdi infrastructure 



MTD already allocates backing_dev_info dynamically. Convert it to use
generic infrastructure for this including proper refcounting. We drop
mtd->backing_dev_info as its only use was to pass mtd_bdi pointer from
one file into another and if we wanted to keep that in a clean way, we'd
have to make mtd hold and drop bdi reference as needed which seems
pointless for passing one global pointer...

CC: David Woodhouse <dwmw2@infradead.org>
CC: Brian Norris <computersforpeace@gmail.com>
CC: linux-mtd@lists.infradead.org
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent edd3ba94

drivers/mtd/mtdcore.c

+12 −11
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ 


#include "mtdcore.h"



static struct backing_dev_info *mtd_bdi;

struct backing_dev_info *mtd_bdi;



#ifdef CONFIG_PM_SLEEP
@@ -496,11 +496,9 @@ int add_mtd_device(struct mtd_info *mtd) 
	 * mtd_device_parse_register() multiple times on the same master MTD,

	 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.

	 */

	if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))

	if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))

		return -EEXIST;



	mtd->backing_dev_info = mtd_bdi;



	BUG_ON(mtd->writesize == 0);

	mutex_lock(&mtd_table_mutex);
@@ -1775,13 +1773,18 @@ static struct backing_dev_info * __init mtd_bdi_init(char *name) 
	struct backing_dev_info *bdi;

	int ret;



	bdi = kzalloc(sizeof(*bdi), GFP_KERNEL);

	bdi = bdi_alloc(GFP_KERNEL);

	if (!bdi)

		return ERR_PTR(-ENOMEM);



	ret = bdi_setup_and_register(bdi, name);

	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. 

	 */

	ret = bdi_register(bdi, NULL, "%.28s-0", name);

	if (ret)

		kfree(bdi);

		bdi_put(bdi);



	return ret ? ERR_PTR(ret) : bdi;

}
@@ -1813,8 +1816,7 @@ static int __init init_mtd(void) 
out_procfs:

	if (proc_mtd)

		remove_proc_entry("mtd", NULL);

	bdi_destroy(mtd_bdi);

	kfree(mtd_bdi);

	bdi_put(mtd_bdi);

err_bdi:

	class_unregister(&mtd_class);

err_reg:
@@ -1828,8 +1830,7 @@ static void __exit cleanup_mtd(void) 
	if (proc_mtd)

		remove_proc_entry("mtd", NULL);

	class_unregister(&mtd_class);

	bdi_destroy(mtd_bdi);

	kfree(mtd_bdi);

	bdi_put(mtd_bdi);

	idr_destroy(&mtd_idr);

}

drivers/mtd/mtdsuper.c

+6 −1
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/ctype.h>

#include <linux/slab.h>

#include <linux/major.h>

#include <linux/backing-dev.h>



/*

 * compare superblocks to see if they're equivalent
@@ -38,6 +39,8 @@ static int get_sb_mtd_compare(struct super_block *sb, void *_mtd) 
	return 0;

}



extern struct backing_dev_info *mtd_bdi;



/*

 * mark the superblock by the MTD device it is using

 * - set the device number to be the correct MTD block device for pesuperstence
@@ -49,7 +52,9 @@ static int get_sb_mtd_set(struct super_block *sb, void *_mtd) 


	sb->s_mtd = mtd;

	sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);

	sb->s_bdi = mtd->backing_dev_info;

	sb->s_bdi = bdi_get(mtd_bdi);

	sb->s_iflags |= SB_I_DYNBDI;



	return 0;

}

include/linux/mtd/mtd.h

+0 −5
Original line number Diff line number Diff line
@@ -334,11 +334,6 @@ struct mtd_info { 
	int (*_get_device) (struct mtd_info *mtd);

	void (*_put_device) (struct mtd_info *mtd);



	/* Backing device capabilities for this device

	 * - provides mmap capabilities

	 */

	struct backing_dev_info *backing_dev_info;



	struct notifier_block reboot_notifier;  /* default mode before reboot */



	/* ECC status information */

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