Merge patch series "'part name' subcommand and some robustification"

Rasmus Villemoes <[email protected]> says:

Implement a "part name" subcommand, mirroring the existing "part
number" subcommand.

In the discussion for v1 of that, it came up that there's a bit of
inconsistency in how much and what one can assume to be initialized in
'struct disk_partition' after a successful call of one of the
get_info* family of functions. Patch 1/2 tries to consolidate
that by making sure all ->get_info invocations go through a common
helper that at least always initializes the string members.

Quentin, I've taken the liberty of including your Acks, as the
incremental diff in patch 1 is quite minor, but do speak up if I
should not have done that.

Link: https://lore.kernel.org/r/[email protected]

1 files changed, 37 insertions, 26 deletions

diff --git a/disk/part.c b/disk/part.c
index be2b45d5a29..49a0fca6b89 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -72,6 +72,28 @@ struct part_driver *part_driver_lookup_type(struct blk_desc *desc)
 	return NULL;
 }
 
+static void disk_partition_clr(struct disk_partition *info)
+{
+	/* The common case is no UUID support */
+	disk_partition_clr_uuid(info);
+	disk_partition_clr_type_guid(info);
+	info->name[0] = '\0';
+	info->type[0] = '\0';
+}
+
+int part_driver_get_info(struct part_driver *drv, struct blk_desc *desc, int part,
+			 struct disk_partition *info)
+{
+	if (!drv->get_info) {
+		log_debug("## Driver %s does not have the get_info() method\n",
+			  drv->name);
+		return -ENOSYS;
+	}
+
+	disk_partition_clr(info);
+	return drv->get_info(desc, part, info);
+}
+
 int part_get_type_by_name(const char *name)
 {
 	struct part_driver *drv =
@@ -322,12 +344,9 @@ int part_get_info_by_type(struct blk_desc *desc, int part, int part_type,
 			  struct disk_partition *info)
 {
 	struct part_driver *drv;
+	int ret = -ENOENT;
 
 	if (blk_enabled()) {
-		/* The common case is no UUID support */
-		disk_partition_clr_uuid(info);
-		disk_partition_clr_type_guid(info);
-
 		if (part_type == PART_TYPE_UNKNOWN) {
 			drv = part_driver_lookup_type(desc);
 		} else {
@@ -339,18 +358,16 @@ int part_get_info_by_type(struct blk_desc *desc, int part, int part_type,
 			      desc->part_type);
 			return -EPROTONOSUPPORT;
 		}
-		if (!drv->get_info) {
-			PRINTF("## Driver %s does not have the get_info() method\n",
-			       drv->name);
-			return -ENOSYS;
-		}
-		if (drv->get_info(desc, part, info) == 0) {
+
+		ret = part_driver_get_info(drv, desc, part, info);
+		if (ret && ret != -ENOSYS) {
+			ret = -ENOENT;
+		} else {
 			PRINTF("## Valid %s partition found ##\n", drv->name);
-			return 0;
 		}
 	}
 
-	return -ENOENT;
+	return ret;
 }
 
 int part_get_info(struct blk_desc *desc, int part,
@@ -657,15 +674,12 @@ int part_get_info_by_name(struct blk_desc *desc, const char *name,
 	if (!part_drv)
 		return -1;
 
-	if (!part_drv->get_info) {
-		log_debug("## Driver %s does not have the get_info() method\n",
-			  part_drv->name);
-		return -ENOSYS;
-	}
-
 	for (i = 1; i < part_drv->max_entries; i++) {
-		ret = part_drv->get_info(desc, i, info);
+		ret = part_driver_get_info(part_drv, desc, i, info);
 		if (ret != 0) {
+			/* -ENOSYS means no ->get_info method. */
+			if (ret == -ENOSYS)
+				return ret;
 			/*
 			 * Partition with this index can't be obtained, but
 			 * further partitions might be, so keep checking.
@@ -695,15 +709,12 @@ int part_get_info_by_uuid(struct blk_desc *desc, const char *uuid,
 	if (!part_drv)
 		return -1;
 
-	if (!part_drv->get_info) {
-		log_debug("## Driver %s does not have the get_info() method\n",
-			  part_drv->name);
-		return -ENOSYS;
-	}
-
 	for (i = 1; i < part_drv->max_entries; i++) {
-		ret = part_drv->get_info(desc, i, info);
+		ret = part_driver_get_info(part_drv, desc, i, info);
 		if (ret != 0) {
+			/* -ENOSYS means no ->get_info method. */
+			if (ret == -ENOSYS)
+				return ret;
 			/*
 			 * Partition with this index can't be obtained, but
 			 * further partitions might be, so keep checking.