[PATCH] f2fs: fix to migrate all curseg types during free_segment_range

[PATCH] f2fs: fix to migrate all curseg types during free_segment_range

[Daeho Jeong]

From: Daeho Jeong <daehojeong@google.com>

In free_segment_range(), the curseg evacuation loop only iterates up to
NR_CURSEG_PERSIST_TYPE (0..5), missing non-persistent in-memory curseg
types such as CURSEG_COLD_DATA_PINNED and CURSEG_ALL_DATA_ATGC.

Even though these in-memory curseg types are not saved in the on-disk
checkpoint header, they still occupy active physical segments at runtime.
If an active in-memory curseg happens to be allocated within the segment
range being truncated during filesystem shrink, failing to evacuate it
will cause subsequent writes to the curseg attempting out-of-bounds I/O
on the truncated storage range.

Fix this by expanding the curseg evacuation loop upper bound to
NR_CURSEG_TYPE to ensure all active curseg types are safely migrated
out of the target range.

Fixes: d0b9e42ab615 ("f2fs: introduce inmem curseg")
Cc: stable@vger.kernel.org
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
---
 fs/f2fs/gc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index ffaa7ba76a1b..192b16ac02f8 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -2222,7 +2222,7 @@ static int free_segment_range(struct f2fs_sb_info *sbi,
 	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
 
 	/* Move out cursegs from the target range */
-	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++) {
+	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++) {
 		err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
 		if (err)
 			goto out;
-- 
2.55.0.691.gc56d675ccc-goog

Re: [f2fs-dev] [PATCH] f2fs: fix to migrate all curseg types during free_segment_range

[Chao Yu]

On 8/20/26 02:06, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
> 
> In free_segment_range(), the curseg evacuation loop only iterates up to
> NR_CURSEG_PERSIST_TYPE (0..5), missing non-persistent in-memory curseg
> types such as CURSEG_COLD_DATA_PINNED and CURSEG_ALL_DATA_ATGC.
> 
> Even though these in-memory curseg types are not saved in the on-disk
> checkpoint header, they still occupy active physical segments at runtime.
> If an active in-memory curseg happens to be allocated within the segment
> range being truncated during filesystem shrink, failing to evacuate it
> will cause subsequent writes to the curseg attempting out-of-bounds I/O
> on the truncated storage range.
> 
> Fix this by expanding the curseg evacuation loop upper bound to
> NR_CURSEG_TYPE to ensure all active curseg types are safely migrated
> out of the target range.
> 
> Fixes: d0b9e42ab615 ("f2fs: introduce inmem curseg")
> Cc: stable@vger.kernel.org
> Signed-off-by: Daeho Jeong <daehojeong@google.com>
> Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

[PATCH] f2fs: fix to migrate all curseg types during free_segment_range

[Daeho Jeong]

From: Daeho Jeong <daehojeong@google.com>

In free_segment_range(), the curseg evacuation loop only iterates up to
NR_CURSEG_PERSIST_TYPE (0..5), missing non-persistent in-memory curseg
types such as CURSEG_COLD_DATA_PINNED and CURSEG_ALL_DATA_ATGC.

Even though these in-memory curseg types are not saved in the on-disk
checkpoint header, they still occupy active physical segments at runtime.
If an active in-memory curseg happens to be allocated within the segment
range being truncated during filesystem shrink, failing to evacuate it
will cause subsequent writes to the curseg attempting out-of-bounds I/O
on the truncated storage range.

Fix this by expanding the curseg evacuation loop upper bound to
NR_CURSEG_TYPE to ensure all active curseg types are safely migrated
out of the target range.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
---
 fs/f2fs/gc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index ffaa7ba76a1b..192b16ac02f8 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -2222,7 +2222,7 @@ static int free_segment_range(struct f2fs_sb_info *sbi,
 	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
 
 	/* Move out cursegs from the target range */
-	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++) {
+	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++) {
 		err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
 		if (err)
 			goto out;
-- 
2.55.0.691.gc56d675ccc-goog