From: ymdatta <ymdatta.work@gmail.com>
To: kernelnewbies@kernelnewbies.org
Subject: Accessing allocated space in a debugfs file
Date: Wed, 30 Sep 2020 22:32:05 +0530 [thread overview]
Message-ID: <a6d49ab7-be8a-9a9c-f313-9088a7329f13@gmail.com> (raw)
Hello everyone,
I am trying to create a debugfs file for exposing some information to the
userspace. (I am exploring on how to use debugfs)
From the documentation (Documentation/filesystems/debugfs.txt), i came
across a function called
struct dentry *debugfs_create_file_size(...,loff_t file_size);
This essentially creates a file with an initial size.
I want to write in this file, how should i be accessing the space created
from previous function call.
I have looked through the source code, but i have found very few places
where this function is used. In one of the use cases [0], the memory
equal to the size is allocated in the open file operation, and the
private_data member is pointed to this. (Looking at [0] helps in
understanding this). But from #kernelnewbies channel, i found that
private_data is a pointer for tty/char drivers.
Thanks for the help.
[0]: https://elixir.bootlin.com/linux/latest/source/drivers/usb/gadget/udc/atmel_usba_udc.c#L140
ymdatta.
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next reply other threads:[~2020-09-30 17:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 17:02 ymdatta [this message]
2020-09-30 17:49 ` Accessing allocated space in a debugfs file Greg KH
2020-10-02 11:29 ` ymdatta
2020-10-02 11:35 ` Greg KH
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