On Tue, Aug 5, 2008 at 11:41 AM, Rene Herman <rene.herman@xxxxxxxxxxxx> wrote:
Got it you are correct. Whatever I have done is not the correct way to do it.
Hmmm, I should use locks, I have not used it. Thanks a lot for letting me know.
I guess that's the best way to do it. Yes, kdb's most part is compiled statically into the kernel. I can export a function in kdb which just calls get_filesystem_list() and returns me the list of filesystems.
Thanks Rene, that is what I wanted. Thanks a lot for spending time and guiding.
On 05-08-08 07:51, Prasad Joshi wrote:Well, that's not really a lot of use other than as a quick hack I'm afraid. First, sysfs needn't even be compiled in, second, I doubt you have any guarentee on ordering even if it is and third, you're racy.
Thanks a lot Rene and Mark,
I am in a phase of learning the Linux Device Drivers. I am trying to write a KDB module. This will add a new command in KDB to display the registered filesystem specific data. Hence I need a way to read all the registered filesystems.
Instead of exporting the function get_filesystem_list() and rebuilding the kernel. I used the other function which is exported get_fs_type(char *); ==> and in the first call to it I passed sysfs (which is the first filesystem registerd, atleast on my machine.)
I got a pointer of type file_system_type and then onwards followed the linklist to get the list of other filesystems registerd.
Got it you are correct. Whatever I have done is not the correct way to do it.
See how get_filesystem_list() grabs a lock to make sure the list is not changed while you're reading it. You can't provide that guarantee without grabbing that same lock and you can't do that since it's local to fs/filesystems.c.
Hmmm, I should use locks, I have not used it. Thanks a lot for letting me know.
You do need get_filesystem_list(). I have played around with kdb but it was long ago. It does have parts which are compiled statically into the kernel, does it not? If so and if this interface is intended to be more than playground you could provide an indirect kdb interface there that calls get_filesystem_list().
I guess that's the best way to do it. Yes, kdb's most part is compiled statically into the kernel. I can export a function in kdb which just calls get_filesystem_list() and returns me the list of filesystems.
Thanks Rene, that is what I wanted. Thanks a lot for spending time and guiding.
Rene.
