[RFC PATCH 06/11] buffer: record blockdev write errors in super_block that backs them

[Jeff Layton]

From: Jeff Layton <jlayton@xxxxxxxxxx>

When syncing out a block device (a'la __sync_blockdev), any error
encountered will only be recorded in the bd_inode's mapping. When the
blockdev contains a filesystem however, we'd like to also record the
error in the super_block that's stored there.

Change mark_buffer_write_io_error to record the error in the
corresponding super_block when a writeback error occurs and the block
device contains a mounted superblock.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/buffer.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/buffer.c b/fs/buffer.c
index 249b83fafe48..dae2a857d5bc 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1117,6 +1117,8 @@ void mark_buffer_write_io_error(struct buffer_head *bh)
 		mapping_set_error(bh->b_page->mapping, -EIO);
 	if (bh->b_assoc_map)
 		mapping_set_error(bh->b_assoc_map, -EIO);
+	if (bh->b_bdev->bd_super)
+		errseq_set(&bh->b_bdev->bd_super->s_wb_err, -EIO);
 }
 EXPORT_SYMBOL(mark_buffer_write_io_error);
 
-- 
2.17.0