If we call xfs_buf_iowait() on a buffer that failed dispatch due to
an IO error, it will wait forever for an Io that does not exist.
This is hndled in xfs_buf_read, but there is other code that calls
xfs_buf_iowait directly that doesn't.
Rather than make the call sites have to handle checking for dispatch
errors and then checking for completion errors, make
xfs_buf_iowait() check for dispatch errors on the buffer before
waiting. This means we handle both dispatch and completion errors
with one set of error handling at the caller sites.
- * Waits for I/O to complete on the buffer supplied.
- * It returns immediately if no I/O is pending.
- * It returns the I/O error code, if any, or 0 if there was no error.
+ * Waits for I/O to complete on the buffer supplied. It returns immediately if
+ * no I/O is pending or there is already a pending error on the buffer. It
+ * returns the I/O error code, if any, or 0 if there was no error.
@@ -1287,7 +1284,8 @@ xfs_buf_iowait(
+ if (!bp->b_error)