f2fs: introduce f2fs_msg to ease adding information prints

From: Namjae Jeon <[email protected]>

Introduced f2fs_msg function to differentiate f2fs specific messages in the log. And, added few informative prints in the mount path, to convey proper error in case of mount failure.

---
 fs/f2fs/f2fs.h  |    2 ++
 fs/f2fs/super.c |   80 +++++++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 65 insertions(+), 17 deletions(-)

index 13c6dfb..8199ee9 100644
@@ -877,6 +877,8 @@ bool f2fs_empty_dir(struct inode *);
  * super.c
  */
 int f2fs_sync_fs(struct super_block *, int);
+extern __printf(3, 4)
+void f2fs_msg(struct super_block *, const char *, const char *, ...);
 
 /*
  * hash.c

1.7.9.5