f2fs: fix handling errors got by f2fs_write_inode

Ruslan reported that f2fs hangs with an infinite loop in f2fs_sync_file():

	while (sync_node_pages(sbi, inode->i_ino, &wbc) == 0)
		f2fs_write_inode(inode, NULL);

The reason was revealed that the cold flag is not set even thought this inode is
a normal file. Therefore, sync_node_pages() skips to write node blocks since it
only writes cold node blocks.

The cold flag is stored to the node_footer in node block, and whenever a new
node page is allocated, it is set according to its file type, file or directory.

But, after sudden-power-off, when recovering the inode page, f2fs doesn't recover
its cold flag.

So, let's assign the cold flag in more right places.

One more thing:
If f2fs_write_inode() returns an error due to whatever situations, there would
be no dirty node pages so that sync_node_pages() returns zero.
(i.e., zero means nothing was written.)

Reported-by: Ruslan N. Marchenko <me@ruff.mobi>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index e1f66df..4a78d6c 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -11,6 +11,7 @@
 #include <linux/fs.h>
 #include <linux/f2fs_fs.h>
 #include "f2fs.h"
+#include "node.h"
 #include "acl.h"
 
 static unsigned long dir_blocks(struct inode *inode)
@@ -308,6 +309,7 @@ static int init_inode_metadata(struct inode *inode, struct dentry *dentry)
 		ipage = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
 		if (IS_ERR(ipage))
 			return PTR_ERR(ipage);
+		set_cold_node(inode, ipage);
 		init_dent_inode(dentry, ipage);
 		f2fs_put_page(ipage, 1);
 	}