[PATCH 3.4 03/19] scsi: handle flush errors properly

Greg Kroah-Hartman
2014-08-05T18:32:30Z

From: James Bottomley <JBottomley@Parallels.com>

commit 89fb4cd1f717a871ef79fa7debbe840e3225cd54 upstream.

Flush commands don't transfer data and thus need to be special cased
in the I/O completion handler so that we can propagate errors to
the block layer and filesystem.

Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Reported-by: Steven Haber <steven@qumulo.com>
Tested-by: Steven Haber <steven@qumulo.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/scsi_lib.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -795,6 +795,14 @@ void scsi_io_completion(struct scsi_cmnd
scsi_next_command(cmd);
return;
}
+ } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
+ /*
+ * Certain non BLOCK_PC requests are commands that don't
+ * actually transfer anything (FLUSH), so cannot use
+ * good_bytes != blk_rq_bytes(req) as the signal for an error.
+ * This sets the error explicitly for the problem case.
+ */
+ error = __scsi_error_from_host_byte(cmd, result);
}

/* no bidi support for !REQ_TYPE_BLOCK_PC yet */