Commit a212b105 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

bdi: make inode_to_bdi() inline 



Now that bdi definitions are moved to backing-dev-defs.h,
backing-dev.h can include blkdev.h and inline inode_to_bdi() without
worrying about introducing circular include dependency.  The function
gets called from hot paths and fairly trivial.

This patch makes inode_to_bdi() and sb_is_blkdev_sb() that the
function calls inline.  blockdev_superblock and noop_backing_dev_info
are EXPORT_GPL'd to allow the inline functions to be used from
modules.

While at it, make sb_is_blkdev_sb() return bool instead of int.

v2: Fixed typo in description as suggested by Jan.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 66114cad

fs/block_dev.c

+2 −6
Original line number Diff line number Diff line
@@ -547,7 +547,8 @@ static struct file_system_type bd_type = { 
	.kill_sb	= kill_anon_super,

};



static struct super_block *blockdev_superblock __read_mostly;

struct super_block *blockdev_superblock __read_mostly;

EXPORT_SYMBOL_GPL(blockdev_superblock);



void __init bdev_cache_init(void)

{
@@ -688,11 +689,6 @@ static struct block_device *bd_acquire(struct inode *inode) 
	return bdev;

}



int sb_is_blkdev_sb(struct super_block *sb)

{

	return sb == blockdev_superblock;

}



/* Call when you free inode */



void bd_forget(struct inode *inode)

fs/fs-writeback.c

+0 −16
Original line number Diff line number Diff line
@@ -78,22 +78,6 @@ int writeback_in_progress(struct backing_dev_info *bdi) 
}

EXPORT_SYMBOL(writeback_in_progress);



struct backing_dev_info *inode_to_bdi(struct inode *inode)

{

	struct super_block *sb;



	if (!inode)

		return &noop_backing_dev_info;



	sb = inode->i_sb;

#ifdef CONFIG_BLOCK

	if (sb_is_blkdev_sb(sb))

		return blk_get_backing_dev_info(I_BDEV(inode));

#endif

	return sb->s_bdi;

}

EXPORT_SYMBOL_GPL(inode_to_bdi);



static inline struct inode *wb_inode(struct list_head *head)

{

	return list_entry(head, struct inode, i_wb_list);

include/linux/backing-dev.h

+16 −2
Original line number Diff line number Diff line
@@ -11,11 +11,10 @@ 
#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/sched.h>

#include <linux/blkdev.h>

#include <linux/writeback.h>

#include <linux/backing-dev-defs.h>



struct backing_dev_info *inode_to_bdi(struct inode *inode);



int __must_check bdi_init(struct backing_dev_info *bdi);

void bdi_destroy(struct backing_dev_info *bdi);
@@ -149,6 +148,21 @@ extern struct backing_dev_info noop_backing_dev_info; 


int writeback_in_progress(struct backing_dev_info *bdi);



static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)

{

	struct super_block *sb;



	if (!inode)

		return &noop_backing_dev_info;



	sb = inode->i_sb;

#ifdef CONFIG_BLOCK

	if (sb_is_blkdev_sb(sb))

		return blk_get_backing_dev_info(I_BDEV(inode));

#endif

	return sb->s_bdi;

}



static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits)

{

	if (bdi->congested_fn)

include/linux/fs.h

+7 −1
Original line number Diff line number Diff line
@@ -2240,7 +2240,13 @@ extern struct super_block *freeze_bdev(struct block_device *); 
extern void emergency_thaw_all(void);

extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);

extern int fsync_bdev(struct block_device *);

extern int sb_is_blkdev_sb(struct super_block *sb);



extern struct super_block *blockdev_superblock;



static inline bool sb_is_blkdev_sb(struct super_block *sb)

{

	return sb == blockdev_superblock;

}

#else

static inline void bd_forget(struct inode *inode) {}

static inline int sync_blockdev(struct block_device *bdev) { return 0; }

mm/backing-dev.c

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ struct backing_dev_info noop_backing_dev_info = { 
	.name		= "noop",

	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK,

};

EXPORT_SYMBOL_GPL(noop_backing_dev_info);



static struct class *bdi_class;

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