From: Ruslan Trofymenko ruslan.trofymenko@linaro.org
This patch adds part_get_info_by_dev_and_name_or_num() function which allows us to get partition info from its number or name. Partition of interest is specified by string like "device_num:partition_number" or "device_num#partition_name".
The patch was extracted from [1].
[1] https://android-review.googlesource.com/c/platform/external/u-boot/+/729880/...
Signed-off-by: Ruslan Trofymenko ruslan.trofymenko@linaro.org Reviewed-by: Alistair Strachan astrachan@google.com Reviewed-by: Sam Protsenko semen.protsenko@linaro.org Reviewed-by: Simon Glass sjg@chromium.org ---
Changes in v3: None Changes in v2: * Error codes are changed to -EINVAL instead of -1
disk/part.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/part.h | 21 ++++++++++++++++++ 2 files changed, 89 insertions(+)
diff --git a/disk/part.c b/disk/part.c index f30f9e9..7b739ad 100644 --- a/disk/part.c +++ b/disk/part.c @@ -675,6 +675,74 @@ int part_get_info_by_name(struct blk_desc *dev_desc, const char *name, return part_get_info_by_name_type(dev_desc, name, info, PART_TYPE_ALL); }
+/** + * Get partition info from device number and partition name. + * + * Parse a device number and partition name string in the form of + * "device_num#partition_name", for example "0#misc". If the partition + * is found, sets dev_desc and part_info accordingly with the information + * of the partition with the given partition_name. + * + * @param[in] dev_iface Device interface + * @param[in] dev_part_str Input string argument, like "0#misc" + * @param[out] dev_desc Place to store the device description pointer + * @param[out] part_info Place to store the partition information + * @return 0 on success, or a negative on error + */ +static int part_get_info_by_dev_and_name(const char *dev_iface, + const char *dev_part_str, + struct blk_desc **dev_desc, + disk_partition_t *part_info) +{ + char *ep; + const char *part_str; + int dev_num; + + part_str = strchr(dev_part_str, '#'); + if (!part_str || part_str == dev_part_str) + return -EINVAL; + + dev_num = simple_strtoul(dev_part_str, &ep, 16); + if (ep != part_str) { + /* Not all the first part before the # was parsed. */ + return -EINVAL; + } + part_str++; + + *dev_desc = blk_get_dev(dev_iface, dev_num); + if (!*dev_desc) { + printf("Could not find %s %d\n", dev_iface, dev_num); + return -EINVAL; + } + if (part_get_info_by_name(*dev_desc, part_str, part_info) < 0) { + printf("Could not find "%s" partition\n", part_str); + return -EINVAL; + } + return 0; +} + +int part_get_info_by_dev_and_name_or_num(const char *dev_iface, + const char *dev_part_str, + struct blk_desc **dev_desc, + disk_partition_t *part_info) +{ + /* Split the part_name if passed as "$dev_num#part_name". */ + if (!part_get_info_by_dev_and_name(dev_iface, dev_part_str, + dev_desc, part_info)) + return 0; + /* + * Couldn't lookup by name, try looking up the partition description + * directly. + */ + if (blk_get_device_part_str(dev_iface, dev_part_str, + dev_desc, part_info, 1) < 0) { + printf("Couldn't find partition %s %s\n", + dev_iface, dev_part_str); + return -EINVAL; + } + return 0; +} + void part_set_generic_name(const struct blk_desc *dev_desc, int part_num, char *name) { diff --git a/include/part.h b/include/part.h index ebca546..0b5cf3d 100644 --- a/include/part.h +++ b/include/part.h @@ -202,6 +202,27 @@ int part_get_info_by_name(struct blk_desc *dev_desc, const char *name, disk_partition_t *info);
/** + * Get partition info from dev number + part name, or dev number + part number. + * + * Parse a device number and partition description (either name or number) + * in the form of device number plus partition name separated by a "#" + * (like "device_num#partition_name") or a device number plus a partition number + * separated by a ":". For example both "0#misc" and "0:1" can be valid + * partition descriptions for a given interface. If the partition is found, sets + * dev_desc and part_info accordingly with the information of the partition. + * + * @param[in] dev_iface Device interface + * @param[in] dev_part_str Input partition description, like "0#misc" or "0:1" + * @param[out] dev_desc Place to store the device description pointer + * @param[out] part_info Place to store the partition information + * @return 0 on success, or a negative on error + */ +int part_get_info_by_dev_and_name_or_num(const char *dev_iface, + const char *dev_part_str, + struct blk_desc **dev_desc, + disk_partition_t *part_info); + +/** * part_set_generic_name() - create generic partition like hda1 or sdb2 * * Helper function for partition tables, which don't hold partition names