Commit a9bddd74 authored by James Bottomley's avatar James Bottomley
Browse files

[SCSI] fix recovered error handling 



We have a problem with recovered error handling in that any command
which goes down as BLOCK_PC but which returns a sense code of RECOVERED
ERROR gets completed with -EIO.  For actual SG_IO commands, this doesn't
matter at all, since the error return code gets dropped in favour of
req->errors which contain the SCSI completion code.

However, if this command is part of the block system, then it will pay
attention to the returned error code.  In particularly if a SYNCHRONIZE
CACHE from a barrier command completes with RECOVERED ERROR, the
resulting -EIO on the barrier causes block to error the request and
return it to the filesystem.  Fix this by converting the -EIO for
recovered error to zero, plus remove the printing of this from sd and sr
so the message isn't double printed.

Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent a2f5bfcf

drivers/scsi/scsi_lib.c

+16 −1
Original line number Diff line number Diff line
@@ -791,7 +791,22 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 
				      "%d bytes done.\n",

				      req->nr_sectors, good_bytes));



	/* A number of bytes were successfully read.  If there

	/*

	 * Recovered errors need reporting, but they're always treated

	 * as success, so fiddle the result code here.  For BLOCK_PC

	 * we already took a copy of the original into rq->errors which

	 * is what gets returned to the user

	 */

	if (sense_valid && sshdr.sense_key == RECOVERED_ERROR) {

		if (!(req->cmd_flags & REQ_QUIET))

			scsi_print_sense("", cmd);

		result = 0;

		/* BLOCK_PC may have set error */

		error = 0;

	}



	/*

	 * A number of bytes were successfully read.  If there

	 * are leftovers and there is some kind of error

	 * (result != 0), retry the rest.

	 */

drivers/scsi/sd.c

+0 −6
Original line number Diff line number Diff line
@@ -1051,12 +1051,6 @@ static int sd_done(struct scsi_cmnd *SCpnt) 
		good_bytes = sd_completed_bytes(SCpnt);

		break;

	case RECOVERED_ERROR:

		/* Inform the user, but make sure that it's not treated

		 * as a hard error.

		 */

		scsi_print_sense("sd", SCpnt);

		SCpnt->result = 0;

		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);

		good_bytes = scsi_bufflen(SCpnt);

		break;

	case NO_SENSE:

drivers/scsi/sr.c

+0 −9
Original line number Diff line number Diff line
@@ -309,15 +309,6 @@ static int sr_done(struct scsi_cmnd *SCpnt) 
			break;



		case RECOVERED_ERROR:



			/*

			 * An error occured, but it recovered.  Inform the

			 * user, but make sure that it's not treated as a

			 * hard error.

			 */

			scsi_print_sense("sr", SCpnt);

			SCpnt->result = 0;

			SCpnt->sense_buffer[0] = 0x0;

			good_bytes = this_count;

			break;

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