f2fs: recover wrong pino after checkpoint during fsync

If a file is linked, f2fs loose its parent inode number so that fsync calls
for the linked file should do checkpoint all the time.
But, if we can recover its parent inode number after the checkpoint, we can
adjust roll-forward mechanism for the further fsync calls, which is able to
improve the fsync performance significatly.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 30 insertions, 1 deletions

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index fda226ff1849..d2d2b7dbdcc1 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -102,6 +102,24 @@ static const struct vm_operations_struct f2fs_file_vm_ops = {
         .remap_pages    = generic_file_remap_pages,
 };
 
+static int get_parent_ino(struct inode *inode, nid_t *pino)
+{
+        struct dentry *dentry;
+
+        inode = igrab(inode);
+        dentry = d_find_any_alias(inode);
+        iput(inode);
+        if (!dentry)
+                return 0;
+
+        inode = igrab(dentry->d_parent->d_inode);
+        dput(dentry);
+
+        *pino = inode->i_ino;
+        iput(inode);
+        return 1;
+}
+
 int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 {
         struct inode *inode = file->f_mapping->host;
@@ -134,7 +152,7 @@ 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_cp_file(inode))
+        else if (file_wrong_pino(inode))
                 need_cp = true;
         else if (!space_for_roll_forward(sbi))
                 need_cp = true;
@@ -142,8 +160,19 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
                 need_cp = true;
 
         if (need_cp) {
+                nid_t pino;
+
                 /* all the dirty node pages should be flushed for POR */
                 ret = f2fs_sync_fs(inode->i_sb, 1);
+                if (file_wrong_pino(inode) && inode->i_nlink == 1 &&
+                                        get_parent_ino(inode, &pino)) {
+                        F2FS_I(inode)->i_pino = pino;
+                        file_got_pino(inode);
+                        mark_inode_dirty_sync(inode);
+                        ret = f2fs_write_inode(inode, NULL);
+                        if (ret)
+                                goto out;
+                }
         } else {
                 /* if there is no written node page, write its inode page */
                 while (!sync_node_pages(sbi, inode->i_ino, &wbc)) {