[PATCH 12/18] misc: storage-by-uuid: prepare for generalizing to different aliases
Marco Felsch
m.felsch at pengutronix.de
Mon Apr 14 03:31:21 PDT 2025
On 25-04-14, Ahmad Fatoum wrote:
> Besides the probe function and the check_exist function, there is
> nothing UUID specific about the code. As preparation for making it
> reusable for arbitrary cdev aliases, rename it to storage-by-alias
> instead as I couldn't figure out a proper backronym for sbu.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
> drivers/misc/storage-by-uuid.c | 204 ++++++++++++++++++---------------
> 1 file changed, 114 insertions(+), 90 deletions(-)
>
> diff --git a/drivers/misc/storage-by-uuid.c b/drivers/misc/storage-by-uuid.c
> index 7bb987dffbec..2795ff93c07c 100644
> --- a/drivers/misc/storage-by-uuid.c
> +++ b/drivers/misc/storage-by-uuid.c
> @@ -1,4 +1,13 @@
> // SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * cdev aliases for existing block devices. In future, this should
> + * likely be replaced by a more generic device mapper support.
> + *
> + * Currently supported targets:
> + * - barebox,storage-by-uuid
> + * Useful for referencing existing EFI disks and their partition
> + * from device tree by offset
> + */
> #include <common.h>
> #include <init.h>
> #include <io.h>
> @@ -7,200 +16,215 @@
> #include <envfs.h>
> #include <fs.h>
>
> -static LIST_HEAD(sbu_list);
> +static LIST_HEAD(sba_list);
>
> -struct sbu {
> - char *uuid;
> +struct sba {
> + char *alias;
> struct device *dev;
> struct cdev *rcdev;
> struct cdev cdev;
> struct list_head list;
> };
>
> -void storage_by_uuid_check_exist(struct cdev *cdev);
> -
> -static ssize_t sbu_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags)
> +static ssize_t sba_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_read(sbu->rcdev, buf, count, offset, flags);
> + return cdev_read(sba->rcdev, buf, count, offset, flags);
> }
>
> -static ssize_t sbu_write(struct cdev *cdev, const void *buf, size_t count, loff_t offset, ulong flags)
> +static ssize_t sba_write(struct cdev *cdev, const void *buf, size_t count, loff_t offset, ulong flags)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_write(sbu->rcdev, buf, count, offset, flags);
> + return cdev_write(sba->rcdev, buf, count, offset, flags);
> }
>
> -static int sbu_ioctl(struct cdev *cdev, unsigned int request, void *buf)
> +static int sba_ioctl(struct cdev *cdev, unsigned int request, void *buf)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_ioctl(sbu->rcdev, request, buf);
> + return cdev_ioctl(sba->rcdev, request, buf);
> }
>
> -static int sbu_open(struct cdev *cdev, unsigned long flags)
> +static int sba_open(struct cdev *cdev, unsigned long flags)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_open(sbu->rcdev, flags);
> + return cdev_open(sba->rcdev, flags);
> }
>
> -static int sbu_close(struct cdev *cdev)
> +static int sba_close(struct cdev *cdev)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - cdev_close(sbu->rcdev);
> + cdev_close(sba->rcdev);
>
> return 0;
> }
>
> -static int sbu_flush(struct cdev *cdev)
> +static int sba_flush(struct cdev *cdev)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_flush(sbu->rcdev);
> + return cdev_flush(sba->rcdev);
> }
>
> -static int sbu_erase(struct cdev *cdev, loff_t count, loff_t offset)
> +static int sba_erase(struct cdev *cdev, loff_t count, loff_t offset)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_erase(sbu->rcdev, count, offset);
> + return cdev_erase(sba->rcdev, count, offset);
> }
>
> -static int sbu_protect(struct cdev *cdev, size_t count, loff_t offset, int prot)
> +static int sba_protect(struct cdev *cdev, size_t count, loff_t offset, int prot)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_protect(sbu->rcdev, count, offset, prot);
> + return cdev_protect(sba->rcdev, count, offset, prot);
> }
>
> -static int sbu_discard_range(struct cdev *cdev, loff_t count, loff_t offset)
> +static int sba_discard_range(struct cdev *cdev, loff_t count, loff_t offset)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_discard_range(sbu->rcdev, count, offset);
> + return cdev_discard_range(sba->rcdev, count, offset);
> }
>
> -static int sbu_memmap(struct cdev *cdev, void **map, int flags)
> +static int sba_memmap(struct cdev *cdev, void **map, int flags)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_memmap(sbu->rcdev, map, flags);
> + return cdev_memmap(sba->rcdev, map, flags);
> }
>
> -static int sbu_truncate(struct cdev *cdev, size_t size)
> +static int sba_truncate(struct cdev *cdev, size_t size)
> {
> - struct sbu *sbu = cdev->priv;
> + struct sba *sba = cdev->priv;
>
> - return cdev_truncate(sbu->rcdev, size);
> + return cdev_truncate(sba->rcdev, size);
> }
>
> -static struct cdev_operations sbu_ops = {
> - .read = sbu_read,
> - .write = sbu_write,
> - .ioctl = sbu_ioctl,
> - .open = sbu_open,
> - .close = sbu_close,
> - .flush = sbu_flush,
> - .erase = sbu_erase,
> - .protect = sbu_protect,
> - .discard_range = sbu_discard_range,
> - .memmap = sbu_memmap,
> - .truncate = sbu_truncate,
> +static struct cdev_operations sba_ops = {
> + .read = sba_read,
> + .write = sba_write,
> + .ioctl = sba_ioctl,
> + .open = sba_open,
> + .close = sba_close,
> + .flush = sba_flush,
> + .erase = sba_erase,
> + .protect = sba_protect,
> + .discard_range = sba_discard_range,
> + .memmap = sba_memmap,
> + .truncate = sba_truncate,
> };
>
> -static void storage_by_uuid_add_partitions(struct sbu *sbu, struct cdev *rcdev)
> +static void sba_add_partitions(struct sba *sba, struct cdev *rcdev)
> {
> int ret;
>
> - if (sbu->rcdev)
> + if (sba->rcdev)
> return;
>
> - sbu->rcdev = rcdev;
> - sbu->cdev.name = sbu->uuid;
> - sbu->cdev.size = rcdev->size;
> - sbu->cdev.ops = &sbu_ops;
> - sbu->cdev.dev = sbu->dev;
> - sbu->cdev.priv = sbu;
> + sba->rcdev = rcdev;
> + sba->cdev.name = sba->alias;
> + sba->cdev.size = rcdev->size;
> + sba->cdev.ops = &sba_ops;
> + sba->cdev.dev = sba->dev;
> + sba->cdev.priv = sba;
>
> if (rcdev->flags & DEVFS_WRITE_AUTOERASE)
> - sbu->cdev.flags |= DEVFS_WRITE_AUTOERASE;
> + sba->cdev.flags |= DEVFS_WRITE_AUTOERASE;
>
> - ret = devfs_create(&sbu->cdev);
> + ret = devfs_create(&sba->cdev);
> if (ret) {
> - dev_err(sbu->dev, "Failed to create cdev: %s\n", strerror(-ret));
> + dev_err(sba->dev, "Failed to create cdev: %s\n", strerror(-ret));
> return;
> }
>
> - of_parse_partitions(&sbu->cdev, sbu->dev->of_node);
> + of_parse_partitions(&sba->cdev, sba->dev->of_node);
> }
>
> -static void check_exist(struct sbu *sbu)
> +static void check_exist(struct sba *sba)
> {
> struct cdev *cdev;
>
> for_each_cdev(cdev) {
> if (cdev_is_partition(cdev))
> continue;
> - if (strcmp(cdev->diskuuid, sbu->uuid))
> + if (strcmp(cdev->diskuuid, sba->alias))
> continue;
>
> - dev_dbg(sbu->dev, "Found %s %s\n", cdev->name, cdev->diskuuid);
> - storage_by_uuid_add_partitions(sbu, cdev);
> + dev_dbg(sba->dev, "Found %s %s\n", cdev->name, cdev->diskuuid);
> + sba_add_partitions(sba, cdev);
> return;
> }
> }
>
> -static int sbu_detect(struct device *dev)
> +static int sba_detect(struct device *dev)
> {
> - struct sbu *sbu = dev->priv;
> + struct sba *sba = dev->priv;
>
> dev_dbg(dev, "%s\n", __func__);
>
> - check_exist(sbu);
> + check_exist(sba);
>
> return 0;
> }
>
> -static int storage_by_uuid_probe(struct device *dev)
> +static int storage_by_uuid_init(struct sba *sba)
> {
> - struct sbu *sbu;
> - int ret;
> const char *uuid;
> + int ret;
>
> - sbu = xzalloc(sizeof(*sbu));
> -
> - ret = of_property_read_string(dev->of_node, "uuid", &uuid);
> + ret = of_property_read_string(sba->dev->of_node, "uuid", &uuid);
> if (ret)
> return ret;
>
> - sbu->dev = dev;
> - sbu->uuid = xstrdup(uuid);
> -
> - list_add_tail(&sbu->list, &sbu_list);
> -
> - check_exist(sbu);
> - dev->priv = sbu;
> - dev->detect = sbu_detect;
> + sba->alias = xstrdup(uuid);
>
> return 0;
> }
>
> -static struct of_device_id storage_by_uuid_dt_ids[] = {
> +static int sba_probe(struct device *dev)
> +{
> + int (*init)(struct sba *);
This does the job but a proper driver_data struct would be the more
aligned to all other drivers.
Regards,
Marco
> + struct sba *sba;
> + int ret;
> +
> + sba = xzalloc(sizeof(*sba));
> + sba->dev = dev;
> +
> + init = device_get_match_data(dev);
> + if (!init)
> + return -ENODEV;
> +
> + ret = init(sba);
> + if (ret)
> + return ret;
> +
> + list_add_tail(&sba->list, &sba_list);
> +
> + check_exist(sba);
> + dev->priv = sba;
> + dev->detect = sba_detect;
> +
> + return 0;
> +}
> +
> +static struct of_device_id sba_dt_ids[] = {
> {
> .compatible = "barebox,storage-by-uuid",
> + .data = storage_by_uuid_init
> }, {
> /* sentinel */
> }
> };
> -MODULE_DEVICE_TABLE(of, storage_by_uuid_dt_ids);
> +MODULE_DEVICE_TABLE(of, sba_dt_ids);
>
> -static struct driver storage_by_uuid_driver = {
> - .name = "storage-by-uuid",
> - .probe = storage_by_uuid_probe,
> - .of_compatible = storage_by_uuid_dt_ids,
> +static struct driver sba_driver = {
> + .name = "storage-by-alias",
> + .probe = sba_probe,
> + .of_compatible = sba_dt_ids,
> };
> -device_platform_driver(storage_by_uuid_driver);
> +device_platform_driver(sba_driver);
> --
> 2.39.5
>
>
>
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