Re: [PATCH v2] ata: libata-scsi: Make __ata_scsi_queuecmd() parameters check more clearly

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2022/1/5 15:39, Damien Le Moal wrote:
On Wed, 2022-01-05 at 15:27 -0500, Wenchao Hao wrote:
This is just a clean code. Since each branch of "if" state would check
scmd->cmd_len, so move the check of scmd->cmd_len out of "if" state to
simplify input parameters check.

And remove redundant init of xlat_func at hand

The patch do not change origin function logic.

Signed-off-by: Wenchao Hao <haowenchao@xxxxxxxxxx>
---
  drivers/ata/libata-scsi.c | 9 ++++-----
  1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 313e9475507b..ab8a2833dfec 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4023,16 +4023,15 @@ int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
  	ata_xlat_func_t xlat_func;
  	int rc = 0;
+ if (unlikely(!scmd->cmd_len))
+		goto bad_cdb_len;
+
  	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
-		if (unlikely(!scmd->cmd_len || scmd->cmd_len > dev->cdb_len))
+		if (unlikely(scmd->cmd_len > dev->cdb_len))
  			goto bad_cdb_len;
xlat_func = ata_get_xlat_func(dev, scsi_op);
  	} else {
-		if (unlikely(!scmd->cmd_len))
-			goto bad_cdb_len;
-
-		xlat_func = NULL;
  		if (likely((scsi_op != ATA_16) || !atapi_passthru16)) {
  			/* relay SCSI command to ATAPI device */
  			int len = COMMAND_SIZE(scsi_op);

Did you miss my reply ?
This change is OK, but while at it, let's cleanup this function further.
I suggested something like this, which includes your changes.


Maybe I misunderstood your previous reply. I think you ask me to change prefix.

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index a16ef0030667..ed8be585a98f 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3958,42 +3958,39 @@ int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
struct ata_device *dev)
  {
  	u8 scsi_op = scmd->cmnd[0];
  	ata_xlat_func_t xlat_func;
-	int rc = 0;
+
+	if (unlikely(!scmd->cmd_len))
+		goto bad_cdb_len;

  	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
-		if (unlikely(!scmd->cmd_len || scmd->cmd_len > dev->cdb_len))
+		if (unlikely(scmd->cmd_len > dev->cdb_len))
  			goto bad_cdb_len;

  		xlat_func = ata_get_xlat_func(dev, scsi_op);
-	} else {
-		if (unlikely(!scmd->cmd_len))
-			goto bad_cdb_len;
+	} else if (scsi_op != ATA_16 || !atapi_passthru16) {
+		/* relay SCSI command to ATAPI device */
+		int len = COMMAND_SIZE(scsi_op);

-		xlat_func = NULL;
-		if (likely((scsi_op != ATA_16) || !atapi_passthru16)) {
-			/* relay SCSI command to ATAPI device */
-			int len = COMMAND_SIZE(scsi_op);
-			if (unlikely(len > scmd->cmd_len ||
-				     len > dev->cdb_len ||
-				     scmd->cmd_len > ATAPI_CDB_LEN))
-				goto bad_cdb_len;
+		if (unlikely(len > scmd->cmd_len ||
+			     len > dev->cdb_len ||
+			     scmd->cmd_len > ATAPI_CDB_LEN))
+			goto bad_cdb_len;

-			xlat_func = atapi_xlat;
-		} else {
-			/* ATA_16 passthru, treat as an ATA command */
-			if (unlikely(scmd->cmd_len > 16))
-				goto bad_cdb_len;
+		xlat_func = atapi_xlat;
+	} else {
+		/* ATA_16 passthru, treat as an ATA command */
+		if (unlikely(scmd->cmd_len > 16))
+			goto bad_cdb_len;

-			xlat_func = ata_get_xlat_func(dev, scsi_op);
-		}
+		xlat_func = ata_get_xlat_func(dev, scsi_op);
  	}

  	if (xlat_func)
-		rc = ata_scsi_translate(dev, scmd, xlat_func);
-	else
-		ata_scsi_simulate(dev, scmd);
+		return ata_scsi_translate(dev, scmd, xlat_func);

-	return rc;
+	ata_scsi_simulate(dev, scmd);
+
+	return 0;

   bad_cdb_len:
  	scmd->result = DID_ERROR << 16;

Do you see any problem with this change ?


This change looks good to me. Should I include this change in next patch? Or you would do this by youself?



[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux