block: introduce new block status code type

Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/ide/ide-eh.c b/drivers/ide/ide-eh.c
index 4b7ffd7d158d..47d5f3379748 100644
--- a/drivers/ide/ide-eh.c
+++ b/drivers/ide/ide-eh.c
@@ -135,7 +135,7 @@ ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
 			return ide_stopped;
 		}
 		scsi_req(rq)->result = err;
-		ide_complete_rq(drive, err ? -EIO : 0, blk_rq_bytes(rq));
+		ide_complete_rq(drive, err ? BLK_STS_IOERR : BLK_STS_OK, blk_rq_bytes(rq));
 		return ide_stopped;
 	}
 
@@ -143,7 +143,7 @@ ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
 }
 EXPORT_SYMBOL_GPL(ide_error);
 
-static inline void ide_complete_drive_reset(ide_drive_t *drive, int err)
+static inline void ide_complete_drive_reset(ide_drive_t *drive, blk_status_t err)
 {
 	struct request *rq = drive->hwif->rq;
 
@@ -151,7 +151,7 @@ static inline void ide_complete_drive_reset(ide_drive_t *drive, int err)
 	    scsi_req(rq)->cmd[0] == REQ_DRIVE_RESET) {
 		if (err <= 0 && scsi_req(rq)->result == 0)
 			scsi_req(rq)->result = -EIO;
-		ide_complete_rq(drive, err ? err : 0, blk_rq_bytes(rq));
+		ide_complete_rq(drive, err, blk_rq_bytes(rq));
 	}
 }
 
@@ -191,7 +191,7 @@ static ide_startstop_t atapi_reset_pollfunc(ide_drive_t *drive)
 	}
 	/* done polling */
 	hwif->polling = 0;
-	ide_complete_drive_reset(drive, 0);
+	ide_complete_drive_reset(drive, BLK_STS_OK);
 	return ide_stopped;
 }
 
@@ -225,7 +225,7 @@ static ide_startstop_t reset_pollfunc(ide_drive_t *drive)
 	ide_hwif_t *hwif = drive->hwif;
 	const struct ide_port_ops *port_ops = hwif->port_ops;
 	u8 tmp;
-	int err = 0;
+	blk_status_t err = BLK_STS_OK;
 
 	if (port_ops && port_ops->reset_poll) {
 		err = port_ops->reset_poll(drive);
@@ -247,7 +247,7 @@ static ide_startstop_t reset_pollfunc(ide_drive_t *drive)
 		printk(KERN_ERR "%s: reset timed-out, status=0x%02x\n",
 			hwif->name, tmp);
 		drive->failures++;
-		err = -EIO;
+		err = BLK_STS_IOERR;
 	} else  {
 		tmp = ide_read_error(drive);
 
@@ -257,7 +257,7 @@ static ide_startstop_t reset_pollfunc(ide_drive_t *drive)
 		} else {
 			ide_reset_report_error(hwif, tmp);
 			drive->failures++;
-			err = -EIO;
+			err = BLK_STS_IOERR;
 		}
 	}
 out:
@@ -392,7 +392,7 @@ static ide_startstop_t do_reset1(ide_drive_t *drive, int do_not_try_atapi)
 
 	if (io_ports->ctl_addr == 0) {
 		spin_unlock_irqrestore(&hwif->lock, flags);
-		ide_complete_drive_reset(drive, -ENXIO);
+		ide_complete_drive_reset(drive, BLK_STS_IOERR);
 		return ide_stopped;
 	}