f2fs: fix to give correct parent inode number for roll forward

When we recover fsync'ed data after power-off-recovery, we should guarantee
that any parent inode number should be correct for each direct inode blocks.

So, let's make the following rules.

- The fsync should do checkpoint to all the inodes that were experienced hard
links.

- So, the only normal files can be recovered by roll-forward.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/f2fs.h

@@ -148,6 +148,7 @@ struct extent_info {
  * i_advise uses FADVISE_XXX_BIT. We can add additional hints later.
  */
 #define FADVISE_COLD_BIT	0x01
+#define FADVISE_CP_BIT		0x02
 
 struct f2fs_inode_info {
 	struct inode vfs_inode;		/* serve a vfs inode */
@@ -825,7 +826,6 @@ static inline int f2fs_clear_bit(unsigned int nr, char *addr)
 /* used for f2fs_inode_info->flags */
 enum {
 	FI_NEW_INODE,		/* indicate newly allocated inode */
-	FI_NEED_CP,		/* need to do checkpoint during fsync */
 	FI_INC_LINK,		/* need to increment i_nlink */
 	FI_ACL_MODE,		/* indicate acl mode */
 	FI_NO_ALLOC,		/* should not allocate any blocks */

fs/f2fs/file.c

@@ -103,23 +103,6 @@ static const struct vm_operations_struct f2fs_file_vm_ops = {
 	.remap_pages	= generic_file_remap_pages,
 };
 
-static int need_to_sync_dir(struct f2fs_sb_info *sbi, struct inode *inode)
-{
-	struct dentry *dentry;
-	nid_t pino;
-
-	inode = igrab(inode);
-	dentry = d_find_any_alias(inode);
-	if (!dentry) {
-		iput(inode);
-		return 0;
-	}
-	pino = dentry->d_parent->d_inode->i_ino;
-	dput(dentry);
-	iput(inode);
-	return !is_checkpointed_node(sbi, pino);
-}
-
 int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	struct inode *inode = file->f_mapping->host;
@@ -149,17 +132,16 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 
 	if (!S_ISREG(inode->i_mode) || inode->i_nlink != 1)
 		need_cp = true;
-	else if (is_inode_flag_set(F2FS_I(inode), FI_NEED_CP))
+	else if (is_cp_file(inode))
 		need_cp = true;
 	else if (!space_for_roll_forward(sbi))
 		need_cp = true;
-	else if (need_to_sync_dir(sbi, inode))
+	else if (!is_checkpointed_node(sbi, F2FS_I(inode)->i_pino))
 		need_cp = true;
 
 	if (need_cp) {
 		/* all the dirty node pages should be flushed for POR */
 		ret = f2fs_sync_fs(inode->i_sb, 1);
-		clear_inode_flag(F2FS_I(inode), FI_NEED_CP);
 	} else {
 		/* if there is no written node page, write its inode page */
 		while (!sync_node_pages(sbi, inode->i_ino, &wbc)) {

fs/f2fs/namei.c

@@ -15,6 +15,7 @@
 #include <linux/ctype.h>
 
 #include "f2fs.h"
+#include "node.h"
 #include "xattr.h"
 #include "acl.h"
 
@@ -99,7 +100,7 @@ static int is_multimedia_file(const unsigned char *s, const char *sub)
 /*
  * Set multimedia files as cold files for hot/cold data separation
  */
-static inline void set_cold_file(struct f2fs_sb_info *sbi, struct inode *inode,
+static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
 		const unsigned char *name)
 {
 	int i;
@@ -108,7 +109,7 @@ static inline void set_cold_file(struct f2fs_sb_info *sbi, struct inode *inode,
 	int count = le32_to_cpu(sbi->raw_super->extension_count);
 	for (i = 0; i < count; i++) {
 		if (!is_multimedia_file(name, extlist[i])) {
-			F2FS_I(inode)->i_advise |= FADVISE_COLD_BIT;
+			set_cold_file(inode);
 			break;
 		}
 	}
@@ -130,7 +131,7 @@ static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 		return PTR_ERR(inode);
 
 	if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
-		set_cold_file(sbi, inode, dentry->d_name.name);
+		set_cold_files(sbi, inode, dentry->d_name.name);
 
 	inode->i_op = &f2fs_file_inode_operations;
 	inode->i_fop = &f2fs_file_operations;
@@ -173,6 +174,12 @@ static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
 	if (err)
 		goto out;
 
+	/*
+	 * This file should be checkpointed during fsync.
+	 * We lost i_pino from now on.
+	 */
+	set_cp_file(inode);
+
 	d_instantiate(dentry, inode);
 	return 0;
 out:
@@ -425,7 +432,6 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 
 	old_inode->i_ctime = CURRENT_TIME;
-	set_inode_flag(F2FS_I(old_inode), FI_NEED_CP);
 	mark_inode_dirty(old_inode);
 
 	f2fs_delete_entry(old_entry, old_page, NULL);

fs/f2fs/node.h

@@ -277,6 +277,21 @@ static inline int is_cold_file(struct inode *inode)
 	return F2FS_I(inode)->i_advise & FADVISE_COLD_BIT;
 }
 
+static inline void set_cold_file(struct inode *inode)
+{
+	F2FS_I(inode)->i_advise |= FADVISE_COLD_BIT;
+}
+
+static inline int is_cp_file(struct inode *inode)
+{
+	return F2FS_I(inode)->i_advise & FADVISE_CP_BIT;
+}
+
+static inline void set_cp_file(struct inode *inode)
+{
+	F2FS_I(inode)->i_advise |= FADVISE_CP_BIT;
+}
+
 static inline int is_cold_data(struct page *page)
 {
 	return PageChecked(page);