[PATCH 6.6.y 1/3] f2fs: fix to reclaim space in f2fs_allocate_pinning_section()

From: Chao Yu

Date: Fri Oct 09 2026 - 07:15:25 EST


From: Chao Yu <chao@xxxxxxxxxx>

[ Upstream commit fa487f56efba6344aef67d871688f0908fe08af3 ]

It needs to trigger checkpoint to free space reclaimed by f2fs_gc_range(),
otherwise, fallocate() on pinfile will fail easily even there is slash
space in conventional zone.

[Testcase]
nullblk_create.sh 512 2 1024 1024
mkfs.f2fs /dev/nullb0 -f -m
mount /dev/nullb0 /mnt/f2fs/
touch /mnt/f2fs/pinfile
f2fs_io pinfile set /mnt/f2fs/pinfile
mkdir /mnt/f2fs/dir/
for((i=0;i<3934;i++)) do { dd if=/dev/zero of=/mnt/f2fs/dir/$i bs=1M count=1;} done
sync
for((i=0;i<3934;i+=2)) do { rm /mnt/f2fs/dir/$i;} done
for((i=0;i<1950;i++)) do { rm /mnt/f2fs/dir/$i;} done
sync
f2fs_io fallocate 0 0 $((1024*1024*1024)) /mnt/f2fs/pinfile
sync
stat /mnt/f2fs/pinfile
f2fs_io fiemap 0 $((1024*1024*1024)) /mnt/f2fs/pinfile

[Before]
fallocate failed: Resource temporarily unavailable
File: /mnt/f2fs/pinfile
Size: 109051904 Blocks: 213208 IO Block: 4096 regular file
Device: 250,0 Inode: 4 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2026-08-12 20:04:02.264000000 +0800
Modify: 2026-08-12 20:04:26.784000000 +0800
Change: 2026-08-12 20:04:26.784000000 +0800
Birth: -
root@localhost:~#
root@localhost:~#
root@localhost:~#
root@localhost:~# f2fs_io fiemap 0 $((1024*1024*1024)) /mnt/f2fs/pinfile
Fiemap: offset = 0 len = 1073741824
logical addr. physical addr. length flags
0 0000000000000000 0000000002e00000 0000000000200000 00001000
1 0000000000200000 000000002dc00000 0000000000400000 00001000
2 0000000000600000 000000002e400000 0000000000600000 00001000
3 0000000000c00000 000000007a400000 0000000005c00000 00001001

[After]
File: /mnt/f2fs/pinfile
Size: 1073741824 Blocks: 2099216 IO Block: 4096 regular file
Device: 250,0 Inode: 4 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2026-08-12 19:47:49.428000000 +0800
Modify: 2026-08-12 19:49:06.808000000 +0800
Change: 2026-08-12 19:49:06.808000000 +0800
Birth: -
Fiemap: offset = 0 len = 1073741824
logical addr. physical addr. length flags
0 0000000000000000 0000000002e00000 0000000000200000 00001000
1 0000000000200000 000000003aa00000 0000000000400000 00001000
2 0000000000600000 000000003b400000 0000000000200000 00001000
3 0000000000800000 000000007a200000 0000000005e00000 00001000
4 0000000006600000 0000000002800000 0000000000200000 00001000
5 0000000006800000 0000000003200000 0000000000400000 00001000
6 0000000006c00000 0000000003000000 0000000000200000 00001000
7 0000000006e00000 0000000003600000 0000000037200000 00001000
8 000000003e000000 000000003b200000 0000000000200000 00001000
9 000000003e200000 000000003a800000 0000000000200000 00001000
10 000000003e400000 000000003ae00000 0000000000400000 00001000
11 000000003e800000 000000003b600000 0000000001800000 00001001

Cc: stable@xxxxxxxxxx
Fixes: 9703d69d9d15 ("f2fs: support file pinning for zoned devices")
Cc: Daeho Jeong <daehojeong@xxxxxxxxxx>
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
[ Chao Yu: backport to 6.6.y:
- retain existing f2fs_up_write(&sbi->gc_lock) as 6.6 lacks lock tracing
- assign err = f2fs_gc_range(...) to check return value as in upstream ]
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
fs/f2fs/segment.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9c27353f384b..c5c94ac40860 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3148,11 +3148,15 @@ int f2fs_allocate_pinning_section(struct f2fs_sb_info *sbi)

if (f2fs_sb_has_blkzoned(sbi) && err && gc_required) {
f2fs_down_write(&sbi->gc_lock);
- f2fs_gc_range(sbi, 0, GET_SEGNO(sbi, FDEV(0).end_blk), true, 1);
+ err = f2fs_gc_range(sbi, 0, GET_SEGNO(sbi, FDEV(0).end_blk), true, 1);
f2fs_up_write(&sbi->gc_lock);
-
- gc_required = false;
- goto retry;
+ if (err)
+ return err;
+ err = f2fs_sync_fs(sbi->sb, 1);
+ if (!err) {
+ gc_required = false;
+ goto retry;
+ }
}

return err;
--
2.49.0