[PATCH 18/49] bdi: make inode_to_bdi() inline

Tejun Heo
2015-04-06T20:22:07Z

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, maske sb_is_blkdev_sb() return bool instead of int.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
---
fs/block_dev.c | 8 ++------
fs/fs-writeback.c | 16 ----------------
include/linux/backing-dev.h | 18 ++++++++++++++++--
include/linux/fs.h | 8 +++++++-
mm/backing-dev.c | 1 +
5 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index e4f5f71..875d41a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -549,7 +549,8 @@ 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)
{
@@ -690,11 +691,6 @@ 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)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 7c2f0bd..4fd264d 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -66,22 +66,6 @@ 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);
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 5e39f7a..7857820 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -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)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b4d71b5..ccf4b64 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2205,7 +2205,13 @@ 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; }
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index ff85ecb..b0707d1 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -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;

--
2.1.0