[PATCH v4 2/4] f2fs: update_sit_entry_for_release() supports consecutive blocks.

[Yi Sun]

This function can process some consecutive blocks at a time.

When using update_sit_entry() to release consecutive blocks,
ensure that the consecutive blocks belong to the same segment.
Because after update_sit_entry_for_realese(), @segno is still
in use in update_sit_entry().

Signed-off-by: Yi Sun <yi.sun@xxxxxxxxxx>
---
 fs/f2fs/segment.c | 75 ++++++++++++++++++++++++++++-------------------
 1 file changed, 45 insertions(+), 30 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index bc761d9b889a..67d2859831e4 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2426,6 +2426,10 @@ static void update_segment_mtime(struct f2fs_sb_info *sbi, block_t blkaddr,
 		SIT_I(sbi)->max_mtime = ctime;
 }
 
+/*
+ * NOTE: when updating multiple blocks at the same time, please ensure
+ * that the consecutive input blocks belong to the same segment.
+ */
 static int update_sit_entry_for_release(struct f2fs_sb_info *sbi, struct seg_entry *se,
 				block_t blkaddr, unsigned int offset, int del)
 {
@@ -2433,42 +2437,48 @@ static int update_sit_entry_for_release(struct f2fs_sb_info *sbi, struct seg_ent
 #ifdef CONFIG_F2FS_CHECK_FS
 	bool mir_exist;
 #endif
+	int i;
+	int del_count = -del;
+
+	f2fs_bug_on(sbi, GET_SEGNO(sbi, blkaddr) != GET_SEGNO(sbi, blkaddr + del_count - 1));
 
-	exist = f2fs_test_and_clear_bit(offset, se->cur_valid_map);
+	for (i = 0; i < del_count; i++) {
+		exist = f2fs_test_and_clear_bit(offset + i, se->cur_valid_map);
 #ifdef CONFIG_F2FS_CHECK_FS
-	mir_exist = f2fs_test_and_clear_bit(offset,
-					se->cur_valid_map_mir);
-	if (unlikely(exist != mir_exist)) {
-		f2fs_err(sbi, "Inconsistent error when clearing bitmap, blk:%u, old bit:%d",
-			blkaddr, exist);
-		f2fs_bug_on(sbi, 1);
-	}
+		mir_exist = f2fs_test_and_clear_bit(offset + i,
+						se->cur_valid_map_mir);
+		if (unlikely(exist != mir_exist)) {
+			f2fs_err(sbi, "Inconsistent error when clearing bitmap, blk:%u, old bit:%d",
+				blkaddr + i, exist);
+			f2fs_bug_on(sbi, 1);
+		}
 #endif
-	if (unlikely(!exist)) {
-		f2fs_err(sbi, "Bitmap was wrongly cleared, blk:%u", blkaddr);
-		f2fs_bug_on(sbi, 1);
-		se->valid_blocks++;
-		del = 0;
-	} else if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
-		/*
-		 * If checkpoints are off, we must not reuse data that
-		 * was used in the previous checkpoint. If it was used
-		 * before, we must track that to know how much space we
-		 * really have.
-		 */
-		if (f2fs_test_bit(offset, se->ckpt_valid_map)) {
-			spin_lock(&sbi->stat_lock);
-			sbi->unusable_block_count++;
-			spin_unlock(&sbi->stat_lock);
+		if (unlikely(!exist)) {
+			f2fs_err(sbi, "Bitmap was wrongly cleared, blk:%u", blkaddr + i);
+			f2fs_bug_on(sbi, 1);
+			se->valid_blocks++;
+			del += 1;
+		} else if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
+			/*
+			 * If checkpoints are off, we must not reuse data that
+			 * was used in the previous checkpoint. If it was used
+			 * before, we must track that to know how much space we
+			 * really have.
+			 */
+			if (f2fs_test_bit(offset + i, se->ckpt_valid_map)) {
+				spin_lock(&sbi->stat_lock);
+				sbi->unusable_block_count++;
+				spin_unlock(&sbi->stat_lock);
+			}
 		}
-	}
 
-	if (f2fs_block_unit_discard(sbi) &&
-			f2fs_test_and_clear_bit(offset, se->discard_map))
-		sbi->discard_blks++;
+		if (f2fs_block_unit_discard(sbi) &&
+				f2fs_test_and_clear_bit(offset + i, se->discard_map))
+			sbi->discard_blks++;
 
-	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
-		se->ckpt_valid_blocks += del;
+		if (!f2fs_test_bit(offset + i, se->ckpt_valid_map))
+			se->ckpt_valid_blocks -= 1;
+	}
 
 	return del;
 }
@@ -2517,6 +2527,11 @@ static int update_sit_entry_for_alloc(struct f2fs_sb_info *sbi, struct seg_entry
 	return del;
 }
 
+/*
+ * If releasing blocks, this function supports updating multiple consecutive blocks
+ * at one time, but please note that these consecutive blocks need to belong to the
+ * same segment.
+ */
 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
 {
 	struct seg_entry *se;
-- 
2.25.1