Re: [PATCH] xfs: do not propagate ENODATA disk errors into xattr code

[Christoph Hellwig <hch@infradead.org>]

On Fri, Aug 22, 2025 at 08:21:37AM -0700, Darrick J. Wong wrote:
> We only flag corruptions for these two error codes, but ENODATA from the
> block layer means "critical medium error".  I take that to mean the
> media has permanently lost whatever was persisted there, right?

It can also be a write error.  But yes, it's what EIO indidcates in
general.  Which is why I really think we should be doing something like
the patch below.  But as I don't have the time to fully shephed this
I'm not trying to block this hack, even if I think the issue will
continue to byte us in the future.

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index f9ef3b2a332a..0252faf038aa 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1290,6 +1290,22 @@ xfs_bwrite(
 	return error;
 }
 
+static int
+xfs_buf_bio_status(
+	struct bio		*bio)
+{
+	switch (bio->bi_status) {
+	case BLK_STS_OK:
+		return 0;
+	case BLK_STS_NOSPC:
+		return -ENOSPC;
+	case BLK_STS_OFFLINE:
+		return -ENODEV;
+	default:
+		return -EIO;
+	}
+}
+
 static void
 xfs_buf_bio_end_io(
 	struct bio		*bio)
@@ -1297,7 +1313,7 @@ xfs_buf_bio_end_io(
 	struct xfs_buf		*bp = bio->bi_private;
 
 	if (bio->bi_status)
-		xfs_buf_ioerror(bp, blk_status_to_errno(bio->bi_status));
+		xfs_buf_ioerror(bp, xfs_buf_bio_status(bio));
 	else if ((bp->b_flags & XBF_WRITE) && (bp->b_flags & XBF_ASYNC) &&
 		 XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_IOERROR))
 		xfs_buf_ioerror(bp, -EIO);