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>

10 files changed, 37 insertions, 36 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 5901937284e7..d7a49dcfa85e 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -273,7 +273,7 @@ void ide_retry_pc(ide_drive_t *drive)
 	ide_requeue_and_plug(drive, failed_rq);
 	if (ide_queue_sense_rq(drive, pc)) {
 		blk_start_request(failed_rq);
-		ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
+		ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(failed_rq));
 	}
 }
 EXPORT_SYMBOL_GPL(ide_retry_pc);
@@ -437,7 +437,8 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 
 	/* No more interrupts */
 	if ((stat & ATA_DRQ) == 0) {
-		int uptodate, error;
+		int uptodate;
+		blk_status_t error;
 
 		debug_log("Packet command completed, %d bytes transferred\n",
 			  blk_rq_bytes(rq));
@@ -490,7 +491,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 
 		if (ata_misc_request(rq)) {
 			scsi_req(rq)->result = 0;
-			error = 0;
+			error = BLK_STS_OK;
 		} else {
 
 			if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
@@ -498,7 +499,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 					scsi_req(rq)->result = -EIO;
 			}
 
-			error = uptodate ? 0 : -EIO;
+			error = uptodate ? BLK_STS_OK : BLK_STS_IOERR;
 		}
 
 		ide_complete_rq(drive, error, blk_rq_bytes(rq));
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 07e5ff3a64c3..d55e44ed82b5 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -228,7 +228,7 @@ static void ide_cd_complete_failed_rq(ide_drive_t *drive, struct request *rq)
 		scsi_req(failed)->sense_len = scsi_req(rq)->sense_len;
 		cdrom_analyze_sense_data(drive, failed);
 
-		if (ide_end_rq(drive, failed, -EIO, blk_rq_bytes(failed)))
+		if (ide_end_rq(drive, failed, BLK_STS_IOERR, blk_rq_bytes(failed)))
 			BUG();
 	} else
 		cdrom_analyze_sense_data(drive, NULL);
@@ -508,7 +508,7 @@ static bool ide_cd_error_cmd(ide_drive_t *drive, struct ide_cmd *cmd)
 		nr_bytes -= cmd->last_xfer_len;
 
 	if (nr_bytes > 0) {
-		ide_complete_rq(drive, 0, nr_bytes);
+		ide_complete_rq(drive, BLK_STS_OK, nr_bytes);
 		return true;
 	}
 
@@ -674,7 +674,7 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
 out_end:
 	if (blk_rq_is_scsi(rq) && rc == 0) {
 		scsi_req(rq)->resid_len = 0;
-		blk_end_request_all(rq, 0);
+		blk_end_request_all(rq, BLK_STS_OK);
 		hwif->rq = NULL;
 	} else {
 		if (sense && uptodate)
@@ -699,7 +699,7 @@ out_end:
 				scsi_req(rq)->resid_len += cmd->last_xfer_len;
 		}
 
-		ide_complete_rq(drive, uptodate ? 0 : -EIO, blk_rq_bytes(rq));
+		ide_complete_rq(drive, uptodate ? BLK_STS_OK : BLK_STS_IOERR, blk_rq_bytes(rq));
 
 		if (sense && rc == 2)
 			ide_error(drive, "request sense failure", stat);
@@ -844,7 +844,7 @@ out_end:
 	if (nsectors == 0)
 		nsectors = 1;
 
-	ide_complete_rq(drive, uptodate ? 0 : -EIO, nsectors << 9);
+	ide_complete_rq(drive, uptodate ? BLK_STS_OK : BLK_STS_IOERR, nsectors << 9);
 
 	return ide_stopped;
 }
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 51c81223e56d..54d4d78ca46a 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -104,7 +104,7 @@ ide_startstop_t ide_dma_intr(ide_drive_t *drive)
 			if ((cmd->tf_flags & IDE_TFLAG_FS) == 0)
 				ide_finish_cmd(drive, cmd, stat);
 			else
-				ide_complete_rq(drive, 0,
+				ide_complete_rq(drive, BLK_STS_OK,
 						blk_rq_sectors(cmd->rq) << 9);
 			return ide_stopped;
 		}
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;
 	}
 
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 8ac6048cd2df..627b1f62a749 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -143,7 +143,7 @@ static ide_startstop_t ide_floppy_issue_pc(ide_drive_t *drive,
 
 		drive->failed_pc = NULL;
 		drive->pc_callback(drive, 0);
-		ide_complete_rq(drive, -EIO, done);
+		ide_complete_rq(drive, BLK_STS_IOERR, done);
 		return ide_stopped;
 	}
 
@@ -248,7 +248,7 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 
 		if (ata_misc_request(rq)) {
 			scsi_req(rq)->result = 0;
-			ide_complete_rq(drive, 0, blk_rq_bytes(rq));
+			ide_complete_rq(drive, BLK_STS_OK, blk_rq_bytes(rq));
 			return ide_stopped;
 		} else
 			goto out_end;
@@ -303,7 +303,7 @@ out_end:
 	drive->failed_pc = NULL;
 	if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0)
 		scsi_req(rq)->result = -EIO;
-	ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
+	ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
 	return ide_stopped;
 }
 
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 323af721f8cb..3a234701d92c 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -54,7 +54,7 @@
 #include <linux/uaccess.h>
 #include <asm/io.h>
 
-int ide_end_rq(ide_drive_t *drive, struct request *rq, int error,
+int ide_end_rq(ide_drive_t *drive, struct request *rq, blk_status_t error,
 	       unsigned int nr_bytes)
 {
 	/*
@@ -112,7 +112,7 @@ void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
 	}
 }
 
-int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
+int ide_complete_rq(ide_drive_t *drive, blk_status_t error, unsigned int nr_bytes)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	struct request *rq = hwif->rq;
@@ -122,7 +122,7 @@ int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
 	 * if failfast is set on a request, override number of sectors
 	 * and complete the whole request right now
 	 */
-	if (blk_noretry_request(rq) && error <= 0)
+	if (blk_noretry_request(rq) && error)
 		nr_bytes = blk_rq_sectors(rq) << 9;
 
 	rc = ide_end_rq(drive, rq, error, nr_bytes);
@@ -149,7 +149,7 @@ void ide_kill_rq(ide_drive_t *drive, struct request *rq)
 			scsi_req(rq)->result = -EIO;
 	}
 
-	ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
+	ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
 }
 
 static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
@@ -272,7 +272,7 @@ static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
  	printk("%s: DRIVE_CMD (null)\n", drive->name);
 #endif
 	scsi_req(rq)->result = 0;
-	ide_complete_rq(drive, 0, blk_rq_bytes(rq));
+	ide_complete_rq(drive, BLK_STS_OK, blk_rq_bytes(rq));
 
  	return ide_stopped;
 }
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index 0977fc1f40ce..08b54bb3b705 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -40,7 +40,7 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 	return ret;
 }
 
-static void ide_end_sync_rq(struct request *rq, int error)
+static void ide_end_sync_rq(struct request *rq, blk_status_t error)
 {
 	complete(rq->end_io_data);
 }
@@ -57,7 +57,7 @@ static int ide_pm_execute_rq(struct request *rq)
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
 		scsi_req(rq)->result = -ENXIO;
-		__blk_end_request_all(rq, 0);
+		__blk_end_request_all(rq, BLK_STS_OK);
 		spin_unlock_irq(q->queue_lock);
 		return -ENXIO;
 	}
@@ -235,7 +235,7 @@ void ide_complete_pm_rq(ide_drive_t *drive, struct request *rq)
 
 	drive->hwif->rq = NULL;
 
-	if (blk_end_request(rq, 0, 0))
+	if (blk_end_request(rq, BLK_STS_OK, 0))
 		BUG();
 }
 
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index a0651f948b76..4d062c568777 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -474,7 +474,7 @@ static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 
 		drive->failed_pc = NULL;
 		drive->pc_callback(drive, 0);
-		ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
+		ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
 		return ide_stopped;
 	}
 	ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index d71199d23c9e..ab1a32cdcb0a 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -318,7 +318,7 @@ static void ide_error_cmd(ide_drive_t *drive, struct ide_cmd *cmd)
 		}
 
 		if (nr_bytes > 0)
-			ide_complete_rq(drive, 0, nr_bytes);
+			ide_complete_rq(drive, BLK_STS_OK, nr_bytes);
 	}
 }
 
@@ -336,7 +336,7 @@ void ide_finish_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat)
 		ide_driveid_update(drive);
 	}
 
-	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));
 }
 
 /*
@@ -394,7 +394,7 @@ out_end:
 	if ((cmd->tf_flags & IDE_TFLAG_FS) == 0)
 		ide_finish_cmd(drive, cmd, stat);
 	else
-		ide_complete_rq(drive, 0, blk_rq_sectors(cmd->rq) << 9);
+		ide_complete_rq(drive, BLK_STS_OK, blk_rq_sectors(cmd->rq) << 9);
 	return ide_stopped;
 out_err:
 	ide_error_cmd(drive, cmd);
diff --git a/drivers/ide/siimage.c b/drivers/ide/siimage.c
index 6a1849bb476c..57eea5a9047f 100644
--- a/drivers/ide/siimage.c
+++ b/drivers/ide/siimage.c
@@ -406,7 +406,7 @@ static int siimage_dma_test_irq(ide_drive_t *drive)
  *	yet.
  */
 
-static int sil_sata_reset_poll(ide_drive_t *drive)
+static blk_status_t sil_sata_reset_poll(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	void __iomem *sata_status_addr
@@ -419,11 +419,11 @@ static int sil_sata_reset_poll(ide_drive_t *drive)
 		if ((sata_stat & 0x03) != 0x03) {
 			printk(KERN_WARNING "%s: reset phy dead, status=0x%08x\n",
 					    hwif->name, sata_stat);
-			return -ENXIO;
+			return BLK_STS_IOERR;
 		}
 	}
 
-	return 0;
+	return BLK_STS_OK;
 }
 
 /**