[U-Boot] [PATCH v7 09/12] cmd: mtd: add 'mtd' command
Boris Brezillon
boris.brezillon at bootlin.com
Thu Sep 6 09:42:16 UTC 2018
On Thu, 6 Sep 2018 09:08:51 +0200
Miquel Raynal <miquel.raynal at bootlin.com> wrote:
> +
> +int mtd_probe_devices(void)
> +{
> + const char *mtdparts = env_get("mtdparts");
> + const char *mtdids = env_get("mtdids");
> + bool remaining_partitions = true;
> + struct mtd_info *mtd;
> + int i;
> +
> + mtd_probe_uclass_mtd_devs();
> +
> + /* Check if mtdparts/mtdids changed since last call, otherwise: exit */
> + if (!strcmp(mtdparts, old_mtdparts) && !strcmp(mtdids, old_mtdids))
> + return CMD_RET_SUCCESS;
> +
> + /* Update the local copy of mtdparts */
> + free(old_mtdparts);
> + free(old_mtdids);
> + old_mtdparts = strdup(mtdparts);
> + old_mtdids = strdup(mtdids);
> +
> + /* If at least one partition is still in use, do not delete anything */
> + mtd_for_each_device(mtd) {
> + if (mtd->usecount) {
> + printf("Partition \"%s\" already in use, aborting\n",
> + mtd->name);
> + return CMD_RET_FAILURE;
> + }
> + }
> +
> + /*
> + * Everything looks clear, remove all partitions. It is not safe to
> + * remove entries from the mtd_for_each_device loop as it uses idr
> + * indexes and the partitions removal is done in bulk (all partitions of
> + * one device at the same time), so break and iterate from start each
> + * time a new partition is found and deleted.
> + */
> + while (remaining_partitions) {
> + remaining_partitions = false;
> + mtd_for_each_device(mtd) {
> + if (!mtd_is_partition(mtd) && mtd_has_partitions(mtd)) {
> + del_mtd_partitions(mtd);
> + remaining_partitions = true;
> + break;
> + }
> + }
> + }
Just a detail, but I think this logic could be moved in moved in
the core (mtd_uboot.c).
> +
> + /* Start the parsing by ignoring the extra 'mtdparts=' prefix, if any */
> + if (strstr(mtdparts, "mtdparts="))
> + mtdparts += 9;
> +
> + /* For each MTD device in mtdparts */
> + while (mtdparts[0] != '\0') {
> + char mtd_name[MTD_NAME_MAX_LEN], *colon;
> + struct mtd_partition *parts;
> + int mtd_name_len, len;
> + int ret;
> +
> + colon = strchr(mtdparts, ':');
> + if (!colon) {
> + printf("Wrong mtdparts: %s\n", mtdparts);
> + return CMD_RET_FAILURE;
> + }
> +
> + mtd_name_len = colon - mtdparts;
> + strncpy(mtd_name, mtdparts, mtd_name_len);
> + mtd_name[mtd_name_len] = '\0';
> + /* Move the pointer forward (including the ':') */
> + mtdparts += mtd_name_len + 1;
> + mtd = get_mtd_device_nm(mtd_name);
> + if (IS_ERR_OR_NULL(mtd)) {
> + char linux_name[MTD_NAME_MAX_LEN];
> +
> + /*
> + * The MTD device named "mtd_name" does not exist. Try
> + * to find a correspondance with an MTD device having
> + * the same type and number as defined in the mtdids.
> + */
> + debug("No device named %s\n", mtd_name);
> + ret = mtd_search_alternate_name(mtd_name, linux_name,
> + MTD_NAME_MAX_LEN);
> + if (!ret)
> + mtd = get_mtd_device_nm(linux_name);
> +
> + /*
> + * If no device could be found, move the mtdparts
> + * pointer forward until the next set of partitions.
> + */
> + if (ret || IS_ERR_OR_NULL(mtd)) {
> + printf("Could not find a valid device for %s\n",
> + mtd_name);
> + mtdparts = strchr(mtdparts, ';');
> + if (mtdparts)
> + mtdparts++;
> +
> + continue;
> + }
> + }
> + put_mtd_device(mtd);
Don't know if the refcounting is a nop or not, but shouldn't we keep
a reference to mtd until we're done manipulating it (after the call to
add_mtd_partitions())?
> +
> + /*
> + * Parse the MTD device partitions. It will update the mtdparts
> + * pointer, create an array of parts (that must be freed), and
> + * return the number of partition structures in the array.
> + */
> + ret = mtd_parse_partitions(mtd, &mtdparts, &parts, &len);
> + if (ret) {
> + printf("Could not parse device %s\n", mtd->name);
> + return CMD_RET_FAILURE;
> + }
> +
> + if (!len)
> + continue;
> +
> + /*
> + * Create the new MTD partitions and free the structures
> + * allocated during the parsing.
> + */
> + add_mtd_partitions(mtd, parts, len);
> +
> + for (i = 0; i < len; i++)
> + free((char *)parts[i].name);
> + free(parts);
I'd recommend creating an helper for parts deletion:
void mtd_free_partitions(struct mtd_partitions *parts,
unsigned int nparts)
{
for (i = 0; i < len; i++)
free(parts[i].name);
free(parts);
}
> + }
> +
> + return CMD_RET_SUCCESS;
> +}
Actually, I think the whole mtd_probe_devices() function (and its
dependencies) should be moved in the core (mtd_uboot.c?) so that other
components (ubi, cmd/mtdparts) can use it without depending/selecting
CONFIG_CMD_MTD.
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