f2fs: sync dir->i_size with its block allocation

If new dentry block is allocated and its i_size is updated, we should update
its inode block together in order to sync i_size and its block allocation.
Otherwise, we can loose additional dentry block due to the unconsistent i_size.

Errorneous Scenario
-------------------

In the recovery routine,
 - recovery_dentry
 | - __f2fs_add_link
 | | - get_new_data_page
 | | | - i_size_write(new_i_size)
 | | | - mark_inode_dirty_sync(dir)
 | | - update_parent_metadata
 | | | - mark_inode_dirty(dir)
 |
 - write_checkpoint
   - sync_dirty_dir_inodes
     - filemap_flush(dentry_blocks)
       - f2fs_write_data_page
         - skip to write the last dentry block due to index < i_size

In the above flow, new_i_size is not updated to its inode block so that the
last dentry block will be lost accordingly.

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

3 files changed, 7 insertions, 5 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 93917e31dbdf..5b145fcc2864 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -339,6 +339,8 @@ repeat:
         if (new_i_size &&
                 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
                 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
+                /* Only the directory inode sets new_i_size */
+                set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
                 mark_inode_dirty_sync(inode);
         }
         return page;
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index eaea5b50d9c1..69ca049b5168 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -370,22 +370,20 @@ error:
 static void update_parent_metadata(struct inode *dir, struct inode *inode,
                                                 unsigned int current_depth)
 {
-        bool need_dir_update = false;
-
         if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
                 if (S_ISDIR(inode->i_mode)) {
                         inc_nlink(dir);
-                        need_dir_update = true;
+                        set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
                 }
                 clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
         }
         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
         if (F2FS_I(dir)->i_current_depth != current_depth) {
                 F2FS_I(dir)->i_current_depth = current_depth;
-                need_dir_update = true;
+                set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
         }
 
-        if (need_dir_update)
+        if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR))
                 update_inode_page(dir);
         else
                 mark_inode_dirty(dir);
@@ -502,6 +500,7 @@ add_dentry:
 
         update_parent_metadata(dir, inode, current_depth);
 fail:
+        clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
         kunmap(dentry_page);
         f2fs_put_page(dentry_page, 1);
         return err;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c344a4d640cb..27edf59ac12c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -859,6 +859,7 @@ enum {
         FI_INC_LINK,            /* need to increment i_nlink */
         FI_ACL_MODE,            /* indicate acl mode */
         FI_NO_ALLOC,            /* should not allocate any blocks */
+        FI_UPDATE_DIR,          /* should update inode block for consistency */
         FI_DELAY_IPUT,          /* used for the recovery */
 };