CODEWITHSUNDEEP
clinux-kernelkernellinux-device-driverdevice-driver
obayhan
obayhan

Reputation: 1732

How to get the node name or path of the character device in kernel

I've got "n" character device in one kernel driver. One read function referred to read pointer.

static struct file_operations fops;
fops.read    = cd_read;

Now i need to know which character device referred when read called from userspace.

static ssize_t cd_read(struct file *filep, char *buffer, size_t len, loff_t *position)
{

    filep->f_path;
}

I tried to get it by filep->f_path at least tried to print it but f_path refers to struct path in fs.h

struct file {
    ...
    struct path     f_path;
    ...
}

dentry and vfsmount in path in path.h refers to 2 undefined struct.

struct dentry;
struct vfsmount;

struct path {
    struct vfsmount *mnt;
    struct dentry *dentry;
};

and stuck in here. So how can i get the node name or path of the character device in kernel?

Upvotes: 1

Views: 1676

Answers (1)

obayhan
obayhan

Reputation: 1732

I found the solution.

filp->f_path.dentry->d_iname

works as described in here:

In Linux, how can I get the filename from the "struct file" structure, while stepping thru the kernel with kgdb?

Upvotes: 2

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