On 12/24/2025 9:16 PM, Yongpeng Yang wrote:
From: Yongpeng Yang <[email protected]>

Nice catch!


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)

What do you think of relocating set_fsync_mark & set_dentry_mark logic
into __write_node_folio(), so that we can cover them w/ existed .node_write
lock in __write_node_folio(), it can avoid checkpoint racing as well.

                                               - f2fs_flush_nat_entries
                                                 : {struct nat_entry}->flag |= 
BIT(IS_CHECKPOINTED)
                                              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 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, and does not affect

If atomic is false, we will encounter such issue as well? or am I missing
something?

                        if (!atomic || folio == last_folio) {
                                set_fsync_mark(folio, 1);
                                percpu_counter_inc(&sbi->rf_node_block_count);
                                if (IS_INODE(folio)) {
                                        if (is_inode_flag_set(inode,
                                                                FI_DIRTY_INODE))
                                                f2fs_update_inode(inode, folio);
                                        set_dentry_mark(folio,
                                                f2fs_need_dentry_mark(sbi, 
ino));
                                }
                                /* may be written by other thread */
                                if (!folio_test_dirty(folio))
                                        folio_mark_dirty(folio);
                        }

Thanks,

regular file fsync operations. Therefore, for atomic file fsync,
sbi->cp_rwsem should be acquired 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: Yongpeng Yang <[email protected]>
---
  fs/f2fs/node.c | 8 +++++++-
  1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 482a362f2625..e482a38444f1 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1854,7 +1854,7 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, 
struct inode *inode,
        struct folio_batch fbatch;
        int ret = 0;
        struct folio *last_folio = NULL;
-       bool marked = false;
+       bool marked = false, locked = false;
        nid_t ino = inode->i_ino;
        int nr_folios;
        int nwritten = 0;
@@ -1889,6 +1889,10 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, 
struct inode *inode,
                        if (ino_of_node(folio) != ino)
                                continue;
+ if (atomic && folio == last_folio) {
+                               f2fs_lock_op(sbi);
+                               locked = true;
+                       }
                        folio_lock(folio);
if (unlikely(!is_node_folio(folio))) {
@@ -1959,6 +1963,8 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, 
struct inode *inode,
                goto retry;
        }
  out:
+       if (locked)
+               f2fs_unlock_op(sbi);
        if (nwritten)
                f2fs_submit_merged_write_cond(sbi, NULL, NULL, ino, NODE);
        return ret;



_______________________________________________
Linux-f2fs-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Reply via email to