[PATCH 3.11 081/137] scsi: handle flush errors properly

From: Luis Henriques
Date: Mon Aug 18 2014 - 05:35:45 EST


3.11.10.15 -stable review patch. If anyone has any objections, please let me know.

------------------

From: James Bottomley <JBottomley@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Reported-by: Steven Haber <steven@xxxxxxxxxx>
Tested-by: Steven Haber <steven@xxxxxxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 124392f3091e..96e537a8604d 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -831,6 +831,14 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
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 */
--
1.9.1

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