FAILED: patch "[PATCH] f2fs: zone: fix to don't fail to grab GC target block on zoned device" failed to apply to 5.10-stable tree

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x fd106ada4dee4b8adefec791ee9b9681b7b77501
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '[email protected]' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Thanks,
Sasha

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

From fd106ada4dee4b8adefec791ee9b9681b7b77501 Mon Sep 17 00:00:00 2001
From: Chao Yu <[email protected]>
Date: Mon, 19 Oct 2026 09:00:32 +0000
Subject: [PATCH] f2fs: zone: fix to don't fail to grab GC target block on
zoned device

With out-of-memory fault injection (inject_type=0x0080800f) on a zoned device, f2fs stopped checkpoint during GC:

F2FS-fs (dm-0): inject kmalloc in f2fs_kmalloc of move_data_block+0xc0b/0x12b0

 Workqueue: dm-1_zwplugs blk_zone_wplug_bio_work
 Call Trace:
  <TASK>
  dump_stack_lvl+0x4d/0x70
  f2fs_stop_checkpoint+0x1df/0x5d0
  f2fs_write_end_bio+0xdbb/0x1320
  blk_zone_wplug_bio_work+0x2aa/0x7d0
  process_one_work+0x5c6/0xde0
  worker_thread+0x403/0xb70
  kthread+0x235/0x2e0
  ret_from_fork+0x2f/0x70
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 F2FS-fs (dm-0): Stopped filesystem due to reason: 3

In move_data_block(), the target block is grabbed from the meta cache after f2fs_allocate_data_block() has allocated newaddr. If grabbing it fails w/ -ENOMEM, recover_block calls f2fs_do_replace_block() to restore the old block address and curseg's next_blkoff, which already points past newaddr, so newaddr is never written. That leaves a hole in a sequential zone: the next write to the zone is not at the write pointer, the zone write plug fails it, and f2fs_write_end_bio() stops checkpoint w/ STOP_CP_REASON_WRITE_FAIL.

move_data_block() allocates newaddr before grabbing its meta page and goes to recover_block if the grab fails since commit 4356e48e6437 ("f2fs crypto: fix incorrect positioning for GCing encrypted data page"), the meta cache only replaced the meta page w/ a meta cache entry. That is harmless on a regular device, but it leaves the hole since f2fs supports host-managed SMR (now zoned block) devices, which only accept writes at the write pointer of a sequential zone.

If newaddr is in a sequential zone, grab the target block w/ F2FS_CACHE_NOFAIL, so nothing can fail between allocating newaddr and writing it. In a conventional zone or on a regular device, skipping newaddr is harmless, so keep the error handling for them.

---
 fs/f2fs/gc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

index 18aa6a12e805d..5b948c92f9813 100644
@@ -1453,8 +1453,16 @@ static int move_data_block(struct inode *inode, block_t bidx,
 		goto up_out;
 	}
 
+	/*
+	 * If newaddr is in a sequential zone, it must be written once it is
+	 * allocated, otherwise it leaves a hole in the zone, and the following
+	 * write to the zone will fail as an unaligned write, so don't fail
+	 * here.
+	 */
 	tentry = f2fs_grab_cache(META_CACHE(fio.sbi), newaddr,
-					F2FS_CACHE_LOCK_CREATE);
+			F2FS_CACHE_LOCK_CREATE |
+			(f2fs_is_sequential_zone_area(fio.sbi, newaddr) ?
+			 F2FS_CACHE_NOFAIL : 0));
 	if (IS_ERR(tentry)) {
 		err = PTR_ERR(tentry);
 		f2fs_put_cache(sentry, true);

2.53.0