1 files changed, 55 insertions, 36 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 6ea81f1d5094..0ca3110d6386 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -136,7 +136,7 @@ static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
 
 #define nilfs_cnt32_ge(a, b)   \
 	(typecheck(__u32, a) && typecheck(__u32, b) && \
-	 ((__s32)(a) - (__s32)(b) >= 0))
+	 ((__s32)((a) - (b)) >= 0))
 
 static int nilfs_prepare_segment_lock(struct super_block *sb,
 				      struct nilfs_transaction_info *ti)
@@ -1639,41 +1639,30 @@ static void nilfs_begin_folio_io(struct folio *folio)
 	folio_unlock(folio);
 }
 
-static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
+/**
+ * nilfs_prepare_write_logs - prepare to write logs
+ * @logs: logs to prepare for writing
+ * @seed: checksum seed value
+ *
+ * nilfs_prepare_write_logs() adds checksums and prepares the block
+ * buffers/folios for writing logs.  In order to stabilize folios of
+ * memory-mapped file blocks by putting them in writeback state before
+ * calculating the checksums, first prepare to write payload blocks other
+ * than segment summary and super root blocks in which the checksums will
+ * be embedded.
+ */
+static void nilfs_prepare_write_logs(struct list_head *logs, u32 seed)
 {
 	struct nilfs_segment_buffer *segbuf;
 	struct folio *bd_folio = NULL, *fs_folio = NULL;
+	struct buffer_head *bh;
 
-	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-		struct buffer_head *bh;
-
-		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
-				    b_assoc_buffers) {
-			if (bh->b_folio != bd_folio) {
-				if (bd_folio) {
-					folio_lock(bd_folio);
-					folio_wait_writeback(bd_folio);
-					folio_clear_dirty_for_io(bd_folio);
-					folio_start_writeback(bd_folio);
-					folio_unlock(bd_folio);
-				}
-				bd_folio = bh->b_folio;
-			}
-		}
-
+	/* Prepare to write payload blocks */
+	list_for_each_entry(segbuf, logs, sb_list) {
 		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
 				    b_assoc_buffers) {
-			if (bh == segbuf->sb_super_root) {
-				if (bh->b_folio != bd_folio) {
-					folio_lock(bd_folio);
-					folio_wait_writeback(bd_folio);
-					folio_clear_dirty_for_io(bd_folio);
-					folio_start_writeback(bd_folio);
-					folio_unlock(bd_folio);
-					bd_folio = bh->b_folio;
-				}
+			if (bh == segbuf->sb_super_root)
 				break;
-			}
 			set_buffer_async_write(bh);
 			if (bh->b_folio != fs_folio) {
 				nilfs_begin_folio_io(fs_folio);
@@ -1681,6 +1670,42 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
 			}
 		}
 	}
+	nilfs_begin_folio_io(fs_folio);
+
+	nilfs_add_checksums_on_logs(logs, seed);
+
+	/* Prepare to write segment summary blocks */
+	list_for_each_entry(segbuf, logs, sb_list) {
+		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
+				    b_assoc_buffers) {
+			mark_buffer_dirty(bh);
+			if (bh->b_folio == bd_folio)
+				continue;
+			if (bd_folio) {
+				folio_lock(bd_folio);
+				folio_wait_writeback(bd_folio);
+				folio_clear_dirty_for_io(bd_folio);
+				folio_start_writeback(bd_folio);
+				folio_unlock(bd_folio);
+			}
+			bd_folio = bh->b_folio;
+		}
+	}
+
+	/* Prepare to write super root block */
+	bh = NILFS_LAST_SEGBUF(logs)->sb_super_root;
+	if (bh) {
+		mark_buffer_dirty(bh);
+		if (bh->b_folio != bd_folio) {
+			folio_lock(bd_folio);
+			folio_wait_writeback(bd_folio);
+			folio_clear_dirty_for_io(bd_folio);
+			folio_start_writeback(bd_folio);
+			folio_unlock(bd_folio);
+			bd_folio = bh->b_folio;
+		}
+	}
+
 	if (bd_folio) {
 		folio_lock(bd_folio);
 		folio_wait_writeback(bd_folio);
@@ -1688,7 +1713,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
 		folio_start_writeback(bd_folio);
 		folio_unlock(bd_folio);
 	}
-	nilfs_begin_folio_io(fs_folio);
 }
 
 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
@@ -2070,10 +2094,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 		nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
 
 		/* Write partial segments */
-		nilfs_segctor_prepare_write(sci);
-
-		nilfs_add_checksums_on_logs(&sci->sc_segbufs,
-					    nilfs->ns_crc_seed);
+		nilfs_prepare_write_logs(&sci->sc_segbufs, nilfs->ns_crc_seed);
 
 		err = nilfs_segctor_write(sci, nilfs);
 		if (unlikely(err))
@@ -2824,8 +2845,6 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
 	if (!nilfs->ns_writer)
 		return -ENOMEM;
 
-	inode_attach_wb(nilfs->ns_bdev->bd_mapping->host, NULL);
-
 	err = nilfs_segctor_start_thread(nilfs->ns_writer);
 	if (unlikely(err))
 		nilfs_detach_log_writer(sb);