On 12/30/2025 4:14 PM, Yongpeng Yang wrote:
From: Yongpeng Yang <[email protected]>

During SPO tests, when mounting F2FS, an -EINVAL error was returned from
f2fs_recover_inode_page. The issue occurred under the following scenario

Thread A                                     Thread B
f2fs_ioc_commit_atomic_write
  - f2fs_do_sync_file // atomic = true
   - f2fs_fsync_node_pages
     : last_folio = inode folio
     : schedule before folio_lock(last_folio) f2fs_write_checkpoint
                                               - block_operations// writeback 
last_folio
                                               - schedule before 
f2fs_flush_nat_entries
     : set_fsync_mark(last_folio, 1)
     : set_dentry_mark(last_folio, 1)
     : folio_mark_dirty(last_folio)
     - __write_node_folio(last_folio)
       : f2fs_down_read(&sbi->node_write)//block
                                               - f2fs_flush_nat_entries
                                                 : {struct nat_entry}->flag |= 
BIT(IS_CHECKPOINTED)
                                               - unblock_operations
                                                 : 
f2fs_up_write(&sbi->node_write)
                                              f2fs_write_checkpoint//return
       : f2fs_do_write_node_page()
f2fs_ioc_commit_atomic_write//return
                                              SPO

Thread A calls f2fs_need_dentry_mark(sbi, ino), and the last_folio has
already been written once. However, the {struct nat_entry}->flag did not
have the IS_CHECKPOINTED set, causing set_dentry_mark(last_folio, 1) and
write last_folio again after Thread B finishes f2fs_write_checkpoint.

After SPO and reboot, it was detected that {struct node_info}->blk_addr
was not NULL_ADDR because Thread B successfully write the checkpoint.

This issue only occurs in atomic write scenarios. For regular file
fsync operations, the folio must be dirty. If
block_operations->f2fs_sync_node_pages successfully submit the folio
write, this path will not be executed. Otherwise, the
f2fs_write_checkpoint will need to wait for the folio write submission
to complete, as sbi->nr_pages[F2FS_DIRTY_NODES] > 0. Therefore, the
situation where f2fs_need_dentry_mark checks that the {struct
nat_entry}->flag /wo the IS_CHECKPOINTED flag, but the folio write has
already been submitted, will not occur.

Therefore, for atomic file fsync, sbi->node_write should be acquired
through __write_node_folio to ensure that the IS_CHECKPOINTED flag
correctly indicates that the checkpoint write has been completed.

Fixes: 608514deba38 ("f2fs: set fsync mark only for the last dnode")
Signed-off-by: Sheng Yong <[email protected]>
Signed-off-by: Jinbao Liu <[email protected]>
Signed-off-by: Yongpeng Yang <[email protected]>

Reviewed-by: Chao Yu <[email protected]>

Thanks,


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