[PATCH] f2fs: reset free segment to prefree status when do_checkpoint() fail

[Yangtao Li]

When do_checkpoint() fails, the prefree bitmap is not cleared,
but these segments are already in the free state. If these segments
are used, the segments in use will be reset to the free state when
f2fs_clear_prefree_segments is called next time.

So reset free segments to prefree status when do_checkpoint() fail
to avoid this situation.

Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
 fs/f2fs/checkpoint.c |  6 ++++--
 fs/f2fs/f2fs.h       |  1 +
 fs/f2fs/segment.c    | 13 +++++++++++++
 fs/f2fs/segment.h    |  7 ++++++-
 4 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index be5415a0dbbc..0200af4d02ef 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1647,10 +1647,12 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	f2fs_save_inmem_curseg(sbi);
 
 	err = do_checkpoint(sbi, cpc);
-	if (err)
+	if (err) {
 		f2fs_release_discard_addrs(sbi);
-	else
+		f2fs_set_free_as_prefree_segments(sbi);
+	} else {
 		f2fs_clear_prefree_segments(sbi, cpc);
+	}
 
 	f2fs_restore_inmem_curseg(sbi);
 stop:
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e2d302ae3a46..1618e9a74e89 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3369,6 +3369,7 @@ bool f2fs_is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr);
 void f2fs_drop_discard_cmd(struct f2fs_sb_info *sbi);
 void f2fs_stop_discard_thread(struct f2fs_sb_info *sbi);
 bool f2fs_issue_discard_timeout(struct f2fs_sb_info *sbi);
+void f2fs_set_free_as_prefree_segments(struct f2fs_sb_info *sbi);
 void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
 					struct cp_control *cpc);
 void f2fs_dirty_to_prefree(struct f2fs_sb_info *sbi);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c2866561263e..334e499a0f43 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1959,6 +1959,19 @@ static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
 	mutex_unlock(&dirty_i->seglist_lock);
 }
 
+void f2fs_set_free_as_prefree_segments(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int segno;
+
+	mutex_lock(&dirty_i->seglist_lock);
+	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi)) {
+		if (__set_test_and_inuse(sbi, segno))
+			test_and_clear_bit(segno, dirty_i->dirty_segmap[PRE]);
+	}
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
 void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
 						struct cp_control *cpc)
 {
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index e9a7a637d688..5da8d1100b87 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -487,19 +487,24 @@ static inline void __set_test_and_free(struct f2fs_sb_info *sbi,
 	spin_unlock(&free_i->segmap_lock);
 }
 
-static inline void __set_test_and_inuse(struct f2fs_sb_info *sbi,
+static inline bool __set_test_and_inuse(struct f2fs_sb_info *sbi,
 		unsigned int segno)
 {
 	struct free_segmap_info *free_i = FREE_I(sbi);
 	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
+	bool is_inuse = false;
 
 	spin_lock(&free_i->segmap_lock);
 	if (!test_and_set_bit(segno, free_i->free_segmap)) {
 		free_i->free_segments--;
 		if (!test_and_set_bit(secno, free_i->free_secmap))
 			free_i->free_sections--;
+	} else {
+		is_inuse = true;
 	}
 	spin_unlock(&free_i->segmap_lock);
+
+	return is_inuse;
 }
 
 static inline void get_sit_bitmap(struct f2fs_sb_info *sbi,
-- 
2.25.1