From 26d61e8347b27a981d647d3ea4ec8c7f462c1fcf Mon Sep 17 00:00:00 2001

From: Alan Stern <stern@rowland.harvard.edu>

Date: Mon, 3 Aug 2015 11:57:21 -0400

Subject: [PATCH 1/2] SCSI: refactor device-matching code in scsi_devinfo.c

In drivers/scsi/scsi_devinfo.c, the scsi_dev_info_list_del_keyed() and

scsi_get_device_flags_keyed() routines contain a large amount of

duplicate code for finding vendor/product matches in a

scsi_dev_info_list.  This patch factors out the duplicate code and

puts it in a separate function, scsi_dev_info_list_find().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>

Suggested-by: Giulio Bernardi <ugilio@gmail.com>

Signed-off-by: James Bottomley <JBottomley@Odin.com>

---

 drivers/scsi/scsi_devinfo.c | 112 ++++++++++++++++----------------------------

 1 file changed, 41 insertions(+), 71 deletions(-)

diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c

index 9f77d23239a2..2f49a224462d 100644

--- a/drivers/scsi/scsi_devinfo.c

+++ b/drivers/scsi/scsi_devinfo.c

@@ -390,25 +390,26 @@ int scsi_dev_info_list_add_keyed(int compatible, char *vendor, char *model,

 EXPORT_SYMBOL(scsi_dev_info_list_add_keyed);

 /**

- * scsi_dev_info_list_del_keyed - remove one dev_info list entry.

+ * scsi_dev_info_list_find - find a matching dev_info list entry.

  * @vendor:	vendor string

  * @model:	model (product) string

  * @key:	specify list to use

  *

  * Description:

- * 	Remove and destroy one dev_info entry for @vendor, @model

+ *	Finds the first dev_info entry matching @vendor, @model

  * 	in list specified by @key.

  *

- * Returns: 0 OK, -error on failure.

+ * Returns: pointer to matching entry, or ERR_PTR on failure.

  **/

-int scsi_dev_info_list_del_keyed(char *vendor, char *model, int key)

+static struct scsi_dev_info_list *scsi_dev_info_list_find(const char *vendor,

+		const char *model, int key)

 {

-	struct scsi_dev_info_list *devinfo, *found = NULL;

+	struct scsi_dev_info_list *devinfo;

 	struct scsi_dev_info_list_table *devinfo_table =

 		scsi_devinfo_lookup_by_key(key);

 	if (IS_ERR(devinfo_table))

-		return PTR_ERR(devinfo_table);

+		return (struct scsi_dev_info_list *) devinfo_table;

 	list_for_each_entry(devinfo, &devinfo_table->scsi_dev_info_list,

 			    dev_info_list) {

@@ -452,25 +453,42 @@ int scsi_dev_info_list_del_keyed(char *vendor, char *model, int key)

 			if (memcmp(devinfo->model, model,

 				   min(max, strlen(devinfo->model))))

 				continue;

-			found = devinfo;

+			return devinfo;

 		} else {

 			if (!memcmp(devinfo->vendor, vendor,

 				     sizeof(devinfo->vendor)) &&

 			     !memcmp(devinfo->model, model,

 				      sizeof(devinfo->model)))

-				found = devinfo;

+				return devinfo;

 		}

-		if (found)

-			break;

 	}

-	if (found) {

-		list_del(&found->dev_info_list);

-		kfree(found);

-		return 0;

-	}

+	return ERR_PTR(-ENOENT);

+}

+

+/**

+ * scsi_dev_info_list_del_keyed - remove one dev_info list entry.

+ * @vendor:	vendor string

+ * @model:	model (product) string

+ * @key:	specify list to use

+ *

+ * Description:

+ *	Remove and destroy one dev_info entry for @vendor, @model

+ *	in list specified by @key.

+ *

+ * Returns: 0 OK, -error on failure.

+ **/

+int scsi_dev_info_list_del_keyed(char *vendor, char *model, int key)

+{

+	struct scsi_dev_info_list *found;

-	return -ENOENT;

+	found = scsi_dev_info_list_find(vendor, model, key);

+	if (IS_ERR(found))

+		return PTR_ERR(found);

+

+	list_del(&found->dev_info_list);

+	kfree(found);

+	return 0;

 }

 EXPORT_SYMBOL(scsi_dev_info_list_del_keyed);

@@ -565,64 +583,16 @@ int scsi_get_device_flags_keyed(struct scsi_device *sdev,

 				int key)

 {

 	struct scsi_dev_info_list *devinfo;

-	struct scsi_dev_info_list_table *devinfo_table;

+	int err;

-	devinfo_table = scsi_devinfo_lookup_by_key(key);

+	devinfo = scsi_dev_info_list_find(vendor, model, key);

+	if (!IS_ERR(devinfo))

+		return devinfo->flags;

-	if (IS_ERR(devinfo_table))

-		return PTR_ERR(devinfo_table);

+	err = PTR_ERR(devinfo);

+	if (err != -ENOENT)

+		return err;

-	list_for_each_entry(devinfo, &devinfo_table->scsi_dev_info_list,

-			    dev_info_list) {

-		if (devinfo->compatible) {

-			/*

-			 * Behave like the older version of get_device_flags.

-			 */

-			size_t max;

-			/*

-			 * XXX why skip leading spaces? If an odd INQUIRY

-			 * value, that should have been part of the

-			 * scsi_static_device_list[] entry, such as "  FOO"

-			 * rather than "FOO". Since this code is already

-			 * here, and we don't know what device it is

-			 * trying to work with, leave it as-is.

-			 */

-			max = 8;	/* max length of vendor */

-			while ((max > 0) && *vendor == ' ') {

-				max--;

-				vendor++;

-			}

-			/*

-			 * XXX removing the following strlen() would be

-			 * good, using it means that for a an entry not in

-			 * the list, we scan every byte of every vendor

-			 * listed in scsi_static_device_list[], and never match

-			 * a single one (and still have to compare at

-			 * least the first byte of each vendor).

-			 */

-			if (memcmp(devinfo->vendor, vendor,

-				    min(max, strlen(devinfo->vendor))))

-				continue;

-			/*

-			 * Skip spaces again.

-			 */

-			max = 16;	/* max length of model */

-			while ((max > 0) && *model == ' ') {

-				max--;

-				model++;

-			}

-			if (memcmp(devinfo->model, model,

-				   min(max, strlen(devinfo->model))))

-				continue;

-			return devinfo->flags;

-		} else {

-			if (!memcmp(devinfo->vendor, vendor,

-				     sizeof(devinfo->vendor)) &&

-			     !memcmp(devinfo->model, model,

-				      sizeof(devinfo->model)))

-				return devinfo->flags;

-		}

-	}

 	/* nothing found, return nothing */

 	if (key != SCSI_DEVINFO_GLOBAL)

 		return 0;

-- 

2.5.0