1 files changed, 28 insertions, 21 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 85a853334771..3335ef352915 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -317,7 +317,7 @@ void nilfs_relax_pressure_in_lock(struct super_block *sb)
 	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_sc_info *sci = nilfs->ns_writer;
 
-	if (!sci || !sci->sc_flush_request)
+	if (sb_rdonly(sb) || unlikely(!sci) || !sci->sc_flush_request)
 		return;
 
 	set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
@@ -733,15 +733,18 @@ static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
 					    struct list_head *listp)
 {
 	struct nilfs_inode_info *ii = NILFS_I(inode);
-	struct address_space *mapping = &ii->i_btnode_cache;
+	struct inode *btnc_inode = ii->i_assoc_inode;
 	struct pagevec pvec;
 	struct buffer_head *bh, *head;
 	unsigned int i;
 	pgoff_t index = 0;
 
+	if (!btnc_inode)
+		return;
+
 	pagevec_init(&pvec);
 
-	while (pagevec_lookup_tag(&pvec, mapping, &index,
+	while (pagevec_lookup_tag(&pvec, btnc_inode->i_mapping, &index,
 					PAGECACHE_TAG_DIRTY)) {
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			bh = head = page_buffers(pvec.pages[i]);
@@ -872,9 +875,11 @@ static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
 		nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
 		nilfs_cpfile_put_checkpoint(
 			nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
-	} else
-		WARN_ON(err == -EINVAL || err == -ENOENT);
-
+	} else if (err == -EINVAL || err == -ENOENT) {
+		nilfs_error(sci->sc_super,
+			    "checkpoint creation failed due to metadata corruption.");
+		err = -EIO;
+	}
 	return err;
 }
 
@@ -888,7 +893,11 @@ static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
 	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
 					  &raw_cp, &bh_cp);
 	if (unlikely(err)) {
-		WARN_ON(err == -EINVAL || err == -ENOENT);
+		if (err == -EINVAL || err == -ENOENT) {
+			nilfs_error(sci->sc_super,
+				    "checkpoint finalization failed due to metadata corruption.");
+			err = -EIO;
+		}
 		goto failed_ibh;
 	}
 	raw_cp->cp_snapshot_list.ssl_next = 0;
@@ -2232,16 +2241,14 @@ int nilfs_construct_segment(struct super_block *sb)
 	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_sc_info *sci = nilfs->ns_writer;
 	struct nilfs_transaction_info *ti;
-	int err;
 
-	if (!sci)
+	if (sb_rdonly(sb) || unlikely(!sci))
 		return -EROFS;
 
 	/* A call inside transactions causes a deadlock. */
 	BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
 
-	err = nilfs_segctor_sync(sci);
-	return err;
+	return nilfs_segctor_sync(sci);
 }
 
 /**
@@ -2273,7 +2280,7 @@ int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
 	struct nilfs_transaction_info ti;
 	int err = 0;
 
-	if (!sci)
+	if (sb_rdonly(sb) || unlikely(!sci))
 		return -EROFS;
 
 	nilfs_transaction_lock(sb, &ti, 0);
@@ -2410,7 +2417,7 @@ nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
 			continue;
 		list_del_init(&ii->i_dirty);
 		truncate_inode_pages(&ii->vfs_inode.i_data, 0);
-		nilfs_btnode_cache_clear(&ii->i_btnode_cache);
+		nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping);
 		iput(&ii->vfs_inode);
 	}
 }
@@ -2769,11 +2776,12 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
 
 	if (nilfs->ns_writer) {
 		/*
-		 * This happens if the filesystem was remounted
-		 * read/write after nilfs_error degenerated it into a
-		 * read-only mount.
+		 * This happens if the filesystem is made read-only by
+		 * __nilfs_error or nilfs_remount and then remounted
+		 * read/write.  In these cases, reuse the existing
+		 * writer.
 		 */
-		nilfs_detach_log_writer(sb);
+		return 0;
 	}
 
 	nilfs->ns_writer = nilfs_segctor_new(sb, root);
@@ -2783,10 +2791,9 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
 	inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL);
 
 	err = nilfs_segctor_start_thread(nilfs->ns_writer);
-	if (err) {
-		kfree(nilfs->ns_writer);
-		nilfs->ns_writer = NULL;
-	}
+	if (unlikely(err))
+		nilfs_detach_log_writer(sb);
+
 	return err;
 }