[PATCH] VFS: export sync_sb_inodes

[Artem Bityutskiy]

This patch exports the 'sync_sb_inodes()' which is needed for
UBIFS because it has to force write-back from time to time.
Namely, the UBIFS budgeting subsystem forces write-back when
its pessimistic callculations show that there is no free
space on the media.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
---
 fs/fs-writeback.c  |   11 +++++++++--
 include/linux/fs.h |    2 ++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 16519fe..25adfc3 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -439,8 +439,8 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * on the writer throttling path, and we get decent balancing between many
  * throttled threads: we don't want them all piling up on inode_sync_wait.
  */
-static void
-sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
+void generic_sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc)
 {
 	const unsigned long start = jiffies;	/* livelock avoidance */
 
@@ -526,6 +526,13 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
 	spin_unlock(&inode_lock);
 	return;		/* Leave any unwritten inodes on s_io */
 }
+EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
+
+static void sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc)
+{
+	generic_sync_sb_inodes(sb, wbc);
+}
 
 /*
  * Start writeback of dirty pagecache data against all unlocked inodes.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d8e2762..f9d2aab 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1729,6 +1729,8 @@ static inline void invalidate_remote_inode(struct inode *inode)
 extern int invalidate_inode_pages2(struct address_space *mapping);
 extern int invalidate_inode_pages2_range(struct address_space *mapping,
 					 pgoff_t start, pgoff_t end);
+extern void generic_sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc);
 extern int write_inode_now(struct inode *, int);
 extern int filemap_fdatawrite(struct address_space *);
 extern int filemap_flush(struct address_space *);
-- 
1.5.4.1