Let block partitions to be represented by a firmware node and hence
allow them to being referenced e.g. for use with blk-nvmem.
Signed-off-by: Daniel Golle <[email protected]>
---
block/partitions/core.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/block/partitions/core.c b/block/partitions/core.c
index ab76e64f0f6c..93d109409905 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -10,6 +10,8 @@
#include <linux/ctype.h>
#include <linux/vmalloc.h>
#include <linux/raid/detect.h>
+#include <linux/property.h>
+
#include "check.h"
static int (*const check_part[])(struct parsed_partitions *) = {
@@ -281,6 +283,43 @@ static ssize_t whole_disk_show(struct device *dev,
}
static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
+static struct fwnode_handle *find_partition_fwnode(struct block_device *bdev)
+{
+ struct fwnode_handle *fw_parts, *fw_part;
+ struct device *ddev = disk_to_dev(bdev->bd_disk);
+ const char *partname, *uuid;
+ u32 partno;
+
+ fw_parts = device_get_named_child_node(ddev, "partitions");
+ if (!fw_parts)
+ fw_parts = device_get_named_child_node(ddev->parent, "partitions");
+
+ if (!fw_parts)
+ return NULL;
+
+ fwnode_for_each_child_node(fw_parts, fw_part) {
+ if (!fwnode_property_read_string(fw_part, "uuid", &uuid) &&
+ (!bdev->bd_meta_info || strncmp(uuid,
+ bdev->bd_meta_info->uuid,
+ PARTITION_META_INFO_UUIDLTH)))
+ continue;
+
+ if (!fwnode_property_read_string(fw_part, "partname", &partname) &&
+ (!bdev->bd_meta_info || strncmp(partname,
+ bdev->bd_meta_info->volname,
+ PARTITION_META_INFO_VOLNAMELTH)))
+ continue;
+
+ if (!fwnode_property_read_u32(fw_part, "partno", &partno) &&
+ bdev_partno(bdev) != partno)
+ continue;
+
+ return fw_part;
+ }
+
+ return NULL;
+}
+
/*
* Must be called either with open_mutex held, before a disk can be opened or
* after all disk users are gone.
@@ -355,6 +394,8 @@ static struct block_device *add_partition(struct gendisk *disk, int partno,
goto out_put;
}
+ device_set_node(pdev, find_partition_fwnode(bdev));
+
/* delay uevent until 'holders' subdir is created */
dev_set_uevent_suppress(pdev, 1);
err = device_add(pdev);
--
2.45.1
Hi Daniel,
On 5/30/24 04:13, Daniel Golle wrote:
> Let block partitions to be represented by a firmware node and hence
> allow them to being referenced e.g. for use with blk-nvmem.
>
> Signed-off-by: Daniel Golle <[email protected]>
> ---
> block/partitions/core.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index ab76e64f0f6c..93d109409905 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -10,6 +10,8 @@
> #include <linux/ctype.h>
> #include <linux/vmalloc.h>
> #include <linux/raid/detect.h>
> +#include <linux/property.h>
> +
> #include "check.h"
>
> static int (*const check_part[])(struct parsed_partitions *) = {
> @@ -281,6 +283,43 @@ static ssize_t whole_disk_show(struct device *dev,
> }
> static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
>
> +static struct fwnode_handle *find_partition_fwnode(struct block_device *bdev)
> +{
> + struct fwnode_handle *fw_parts, *fw_part;
> + struct device *ddev = disk_to_dev(bdev->bd_disk);
> + const char *partname, *uuid;
> + u32 partno;
> +
> + fw_parts = device_get_named_child_node(ddev, "partitions");
> + if (!fw_parts)
> + fw_parts = device_get_named_child_node(ddev->parent, "partitions");
Could you please explain why you try to get the node from the device and
the parent when it is not available? I think this should go into the
commit description.
> +
> + if (!fw_parts)
> + return NULL;
> +
> + fwnode_for_each_child_node(fw_parts, fw_part) {
> + if (!fwnode_property_read_string(fw_part, "uuid", &uuid) &&
> + (!bdev->bd_meta_info || strncmp(uuid,
> + bdev->bd_meta_info->uuid,
> + PARTITION_META_INFO_UUIDLTH)))
I think you should check that the uuid provided in the device tree is
not longer than PARTITION_META_INFO_UUIDLTH. Same for the volume name.
> + continue;
> +
> + if (!fwnode_property_read_string(fw_part, "partname", &partname) &&
> + (!bdev->bd_meta_info || strncmp(partname,
> + bdev->bd_meta_info->volname,
> + PARTITION_META_INFO_VOLNAMELTH)))
> + continue;
> +
> + if (!fwnode_property_read_u32(fw_part, "partno", &partno) &&
> + bdev_partno(bdev) != partno)
> + continue;
> +
> + return fw_part;
> + }
> +
> + return NULL;
> +}
> +
> /*
> * Must be called either with open_mutex held, before a disk can be opened or
> * after all disk users are gone.
> @@ -355,6 +394,8 @@ static struct block_device *add_partition(struct gendisk *disk, int partno,
> goto out_put;
> }
>
> + device_set_node(pdev, find_partition_fwnode(bdev));
> +
> /* delay uevent until 'holders' subdir is created */
> dev_set_uevent_suppress(pdev, 1);
> err = device_add(pdev);
Hauke