diff mbox

[v2,6/6] scsi_io_completion convert BUGs to WARNs

Message ID 20180318205904.28541-7-dgilbert@interlog.com (mailing list archive)
State Superseded
Headers show

Commit Message

Douglas Gilbert March 18, 2018, 8:59 p.m. UTC
The scsi_io_completion function contains three BUG() and BUG_ON() calls.
Replace them with WARN variants.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
This was done at a reviewer's request. This patchset did not change those
BUG() lines but the git-diff suggested it did. Then the checkpatch.pl
warned "BUG() calls considered harmful". BUG() calls are simpler than
WARNs because the programmer doesn't have to worry about a continuation
after them. The continuations given here may not be ideal. For these
reasons the author considers this patch optional.

 drivers/scsi/scsi_lib.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

Comments

Johannes Thumshirn March 19, 2018, 8:58 a.m. UTC | #1
Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Bart Van Assche March 27, 2018, 12:19 a.m. UTC | #2
On Sun, 2018-03-18 at 21:59 +0100, Douglas Gilbert wrote:
> --- a/drivers/scsi/scsi_lib.c

> +++ b/drivers/scsi/scsi_lib.c

> @@ -1048,13 +1048,20 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)

>  			scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid;

>  			if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req),

>  					blk_rq_bytes(req->next_rq)))

> -				BUG();

> +				WARN(true, "Bidi command with remaining bytes");

>  			return;

>  		}

>  	}

>  

>  	/* no bidi support yet, other than in pass-through */

> -	BUG_ON(blk_bidi_rq(req));

> +	if (unlikely(blk_bidi_rq(req))) {

> +		WARN_ONCE(true, "Only support bidi command in passthrough");

> +		scmd_printk(KERN_ERR, cmd, "Killing bidi command\n");

> +		if (scsi_end_request(req, BLK_STS_IOERR, blk_rq_bytes(req),

> +				     blk_rq_bytes(req->next_rq)))

> +			WARN(true, "Bidi command with remaining bytes");

> +		return;

> +	}

>  

>  	/*

>  	 * Next deal with any sectors which we were able to correctly

> @@ -1077,7 +1084,8 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)

>  	/* Kill remainder if no retrys  */

>  	if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) {

>  		if (scsi_end_request(req, blk_stat, blk_rq_bytes(req), 0))

> -			BUG();

> +			WARN(true,

> +			    "Bytes remaining after failed, no-retry command");

>  		return;

>  	}

>  


Shouldn't the WARN() calls be changed into WARN_ONCE() calls to avoid that a
large number of complaints appears on the console if these conditions are hit
repeatedly?

Thanks,

Bart.
diff mbox

Patch

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 63f79b0dbbf3..be8836d984f5 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1048,13 +1048,20 @@  void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 			scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid;
 			if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req),
 					blk_rq_bytes(req->next_rq)))
-				BUG();
+				WARN(true, "Bidi command with remaining bytes");
 			return;
 		}
 	}
 
 	/* no bidi support yet, other than in pass-through */
-	BUG_ON(blk_bidi_rq(req));
+	if (unlikely(blk_bidi_rq(req))) {
+		WARN_ONCE(true, "Only support bidi command in passthrough");
+		scmd_printk(KERN_ERR, cmd, "Killing bidi command\n");
+		if (scsi_end_request(req, BLK_STS_IOERR, blk_rq_bytes(req),
+				     blk_rq_bytes(req->next_rq)))
+			WARN(true, "Bidi command with remaining bytes");
+		return;
+	}
 
 	/*
 	 * Next deal with any sectors which we were able to correctly
@@ -1077,7 +1084,8 @@  void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 	/* Kill remainder if no retrys  */
 	if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) {
 		if (scsi_end_request(req, blk_stat, blk_rq_bytes(req), 0))
-			BUG();
+			WARN(true,
+			    "Bytes remaining after failed, no-retry command");
 		return;
 	}