f2fs: fix conditions to remain recovery information in f2fs_sync_file

This patch revisited whole the recovery information during the f2fs_sync_file.

In this patch, there are three information to make a decision.

a) IS_CHECKPOINTED,	/* is it checkpointed before? */
b) HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
c) HAS_LAST_FSYNC,	/* has the latest node fsync mark? */

And, the scenarios for our rule are based on:

[Term] F: fsync_mark, D: dentry_mark

1. inode(x) | CP | inode(x) | dnode(F)
2. inode(x) | CP | inode(F) | dnode(F)
3. inode(x) | CP | dnode(F) | inode(x) | inode(F)
4. inode(x) | CP | dnode(F) | inode(F)
5. CP | inode(x) | dnode(F) | inode(DF)
6. CP | inode(DF) | dnode(F)
7. CP | dnode(F) | inode(DF)
8. CP | dnode(F) | inode(x) | inode(DF)

For example, #3, the three conditions should be changed as follows.

   inode(x) | CP | dnode(F) | inode(x) | inode(F)
a)    x       o      o          o          o
b)    x       x      x          x          o
c)    x       o      o          x          o

If f2fs_sync_file stops   ------^,
 it should write inode(F)    --------------^

So, the need_inode_block_update should return true, since
 c) get_nat_flag(e, HAS_LAST_FSYNC), is false.

For example, #8,
      CP | alloc | dnode(F) | inode(x) | inode(DF)
a)    o      x        x          x          x
b)    x               x          x          o
c)    o               o          x          o

If f2fs_sync_file stops   -------^,
 it should write inode(DF)    --------------^

Note that, the roll-forward policy should follow this rule, which means,
if there are any missing blocks, we doesn't need to recover that inode.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index af06e22..3035c79 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -207,15 +207,17 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 			up_write(&fi->i_sem);
 		}
 	} else {
-		/* if there is no written node page, write its inode page */
-		while (!sync_node_pages(sbi, ino, &wbc)) {
-			if (fsync_mark_done(sbi, ino))
-				goto out;
+sync_nodes:
+		sync_node_pages(sbi, ino, &wbc);
+
+		if (need_inode_block_update(sbi, ino)) {
 			mark_inode_dirty_sync(inode);
 			ret = f2fs_write_inode(inode, NULL);
 			if (ret)
 				goto out;
+			goto sync_nodes;
 		}
+
 		ret = wait_on_node_pages_writeback(sbi, ino);
 		if (ret)
 			goto out;