On 30/09/20 11:19 pm, Greg KH wrote: > On Wed, Sep 30, 2020 at 10:32:05PM +0530, ymdatta wrote: >> >> I want to write in this file, how should i be accessing the space created >> from previous function call. > > That's not what "size" means here. "size" just sets the value that you > see if you look at the directory for that debugfs file (or stat() it). > Didn't realize this. Why do we need this then? What does this 'size' help in achieving (or) where is this used? > debugfs is a virtual filesystem, there is no "backing store" or place to > put your data in it. It is there so that you can write code that can > handle open/read/write/close to happen on a file, and your code will > provide the data to userspace directly. > > The simplest way to create a debugfs file is to just point it at a > variable, and then you can change the variable value in the kernel, and > userspace reading from the file will see whatever the value is at that > point in time. This clears up a lot of my doubts. Thanks! ymdatta. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
