FAILED: patch "[PATCH] f2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 7633a7387eb4d0259d6bea945e1d3469cd135bbc
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026021729-asparagus-duration-50da@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7633a7387eb4d0259d6bea945e1d3469cd135bbc Mon Sep 17 00:00:00 2001
From: Yongpeng Yang <[email protected]>
Date: Tue, 6 Jan 2026 20:12:11 +0800
Subject: [PATCH] f2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by
concurrent atomic commit and checkpoint writes

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.

index d378549010e6..99e425e8c00a 100644
@@ -1786,8 +1786,13 @@ static bool __write_node_folio(struct folio *folio, bool atomic, bool *submitted
 		goto redirty_out;
 	}
 
-	if (atomic && !test_opt(sbi, NOBARRIER))
-		fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+	if (atomic) {
+		if (!test_opt(sbi, NOBARRIER))
+			fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+		if (IS_INODE(folio))
+			set_dentry_mark(folio,
+				f2fs_need_dentry_mark(sbi, ino_of_node(folio)));
+	}
 
 	/* should add to global list before clearing PAGECACHE status */
 	if (f2fs_in_warm_node_list(sbi, folio)) {

@@ -1928,8 +1933,9 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
 					if (is_inode_flag_set(inode,
 								FI_DIRTY_INODE))
 						f2fs_update_inode(inode, folio);
-					set_dentry_mark(folio,
-						f2fs_need_dentry_mark(sbi, ino));
+					if (!atomic)
+						set_dentry_mark(folio,
+							f2fs_need_dentry_mark(sbi, ino));
 				}
 				/* may be written by other thread */
 				if (!folio_test_dirty(folio))

From: Yongpeng Yang <[email protected]>

[ Upstream commit 7633a7387eb4d0259d6bea945e1d3469cd135bbc ]

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.

---
 fs/f2fs/node.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

index 720768d574ae6..1f4f68e56d432 100644
@@ -1713,8 +1713,13 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 		goto redirty_out;
 	}
 
-	if (atomic && !test_opt(sbi, NOBARRIER))
-		fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+	if (atomic) {
+		if (!test_opt(sbi, NOBARRIER))
+			fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+		if (IS_INODE(page))
+			set_dentry_mark(page,
+				f2fs_need_dentry_mark(sbi, ino_of_node(page)));
+	}
 
 	/* should add to global list before clearing PAGECACHE status */
 	if (f2fs_in_warm_node_list(sbi, page)) {

@@ -1869,8 +1874,9 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
 					if (is_inode_flag_set(inode,
 								FI_DIRTY_INODE))
 						f2fs_update_inode(inode, page);
-					set_dentry_mark(page,
-						f2fs_need_dentry_mark(sbi, ino));
+					if (!atomic)
+						set_dentry_mark(page,
+							f2fs_need_dentry_mark(sbi, ino));
 				}
 				/* may be written by other thread */
 				if (!PageDirty(page))

2.51.0