[PATCH] cdev: fix mtd partition handling

[PATCH] cdev: fix mtd partition handling

[Sascha Hauer]

devfs-core.c implements the partition handling only for devices that are
not MTD devices. MTD devices have their own partition handling in
drivers/mtd/partition.c, see the special case in __devfs_add_partition()
for MTD devices. This means for MTD devices we have to pass the original
cdev to the ops, not the master cdev.

Fixes: 6d2b6f399c07 ("cdev: pass master cdev to cdev ops")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 fs/devfs-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/devfs-core.c b/fs/devfs-core.c
index 52490576b7..9c2dae5545 100644
--- a/fs/devfs-core.c
+++ b/fs/devfs-core.c
@@ -226,6 +226,10 @@ int cdev_find_free_index(const char *basename)
 
 static struct cdev *cdev_get_master(struct cdev *cdev)
 {
+	/* mtd devices handle partitions themselves */
+	if (cdev->mtd)
+		return cdev;
+
 	while (cdev && cdev_is_partition(cdev))
 		cdev = cdev->master;
 
-- 
2.39.5

Re: [PATCH] cdev: fix mtd partition handling

[Stefano Manni]

On mar, ago 5 2025 at 09:25:37 +02:00:00, Sascha Hauer 
<s.hauer@pengutronix.de> wrote:
> devfs-core.c implements the partition handling only for devices that 
> are
> not MTD devices. MTD devices have their own partition handling in
> drivers/mtd/partition.c, see the special case in 
> __devfs_add_partition()
> for MTD devices. This means for MTD devices we have to pass the 
> original
> cdev to the ops, not the master cdev.
> 
> Fixes: 6d2b6f399c07 ("cdev: pass master cdev to cdev ops")
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  fs/devfs-core.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/devfs-core.c b/fs/devfs-core.c
> index 52490576b7..9c2dae5545 100644
> --- a/fs/devfs-core.c
> +++ b/fs/devfs-core.c
> @@ -226,6 +226,10 @@ int cdev_find_free_index(const char *basename)
> 
>  static struct cdev *cdev_get_master(struct cdev *cdev)
>  {
> +	/* mtd devices handle partitions themselves */
> +	if (cdev->mtd)
> +		return cdev;
> +
>  	while (cdev && cdev_is_partition(cdev))
>  		cdev = cdev->master;
> 
> --
> 2.39.5
> 

Tested-by: Stefano Manni <stefano.manni@gmail.com>

Re: [PATCH] cdev: fix mtd partition handling

[Sascha Hauer]

On Tue, 05 Aug 2025 09:25:37 +0200, Sascha Hauer wrote:
> devfs-core.c implements the partition handling only for devices that are
> not MTD devices. MTD devices have their own partition handling in
> drivers/mtd/partition.c, see the special case in __devfs_add_partition()
> for MTD devices. This means for MTD devices we have to pass the original
> cdev to the ops, not the master cdev.
> 
> 
> [...]

Applied, thanks!

[1/1] cdev: fix mtd partition handling
      https://git.pengutronix.de/cgit/barebox/commit/?id=52aa463c0662 (link may not be stable)

Best regards,
-- 
Sascha Hauer <s.hauer@pengutronix.de>