block/partitions/cmdline.c

Source file repositories/reference/linux-study-clean/block/partitions/cmdline.c

File Facts

System
Linux kernel
Corpus path
block/partitions/cmdline.c
Extension
.c
Size
8045 bytes
Lines
384
Domain
Representative Device Path
Bucket
PCIe NVMe Storage Path
Inferred role
Representative Device Path: implementation source
Status
source implementation candidate

Why This File Exists

Part of the selected hardware vertical slice: PCI discovery, driver binding, NVMe queues, block requests, DMA, interrupts, and completion.

Dependency Surface

Detected Declarations

Annotated Snippet

struct cmdline_subpart {
	char name[BDEVNAME_SIZE]; /* partition name, such as 'rootfs' */
	sector_t from;
	sector_t size;
	int flags;
	struct cmdline_subpart *next_subpart;
};

struct cmdline_parts {
	char name[BDEVNAME_SIZE]; /* block device, such as 'mmcblk0' */
	unsigned int nr_subparts;
	struct cmdline_subpart *subpart;
	struct cmdline_parts *next_parts;
};

static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
{
	int ret = 0;
	struct cmdline_subpart *new_subpart;

	*subpart = NULL;

	new_subpart = kzalloc_obj(struct cmdline_subpart);
	if (!new_subpart)
		return -ENOMEM;

	if (*partdef == '-') {
		new_subpart->size = (sector_t)(~0ULL);
		partdef++;
	} else {
		new_subpart->size = (sector_t)memparse(partdef, &partdef);
		if (new_subpart->size < (sector_t)PAGE_SIZE) {
			pr_warn("cmdline partition size is invalid.");
			ret = -EINVAL;
			goto fail;
		}
	}

	if (*partdef == '@') {
		partdef++;
		new_subpart->from = (sector_t)memparse(partdef, &partdef);
	} else {
		new_subpart->from = (sector_t)(~0ULL);
	}

	if (*partdef == '(') {
		partdef++;
		char *next = strsep(&partdef, ")");

		if (!next) {
			pr_warn("cmdline partition format is invalid.");
			ret = -EINVAL;
			goto fail;
		}

		strscpy(new_subpart->name, next, sizeof(new_subpart->name));
	} else
		new_subpart->name[0] = '\0';

	new_subpart->flags = 0;

	if (!strncmp(partdef, "ro", 2)) {
		new_subpart->flags |= PF_RDONLY;
		partdef += 2;
	}

	if (!strncmp(partdef, "lk", 2)) {
		new_subpart->flags |= PF_POWERUP_LOCK;
		partdef += 2;
	}

	*subpart = new_subpart;
	return 0;
fail:
	kfree(new_subpart);
	return ret;
}

static void free_subpart(struct cmdline_parts *parts)
{
	struct cmdline_subpart *subpart;

	while (parts->subpart) {
		subpart = parts->subpart;
		parts->subpart = subpart->next_subpart;
		kfree(subpart);
	}
}

static int parse_parts(struct cmdline_parts **parts, char *bdevdef)

Annotation

Implementation Notes