Re: Linux Kernel readlink equivalent

[Aruna Hewapathirane <aruna.hewapathirane@xxxxxxxxx>]

>>

Hello,

I'm working on some linux kernel driver stuff and I have a fake path called /dev/blah/whatever that points to /dev/block/real_device.

The issue is that lookup_bdev will fail to follow the symlink so I'd like to massage the path upfront by getting the real path (/dev/block/real_device) so I can hand that off to lookup_bdev so it returns successfully instead of an error.

Or any other kernel call that would correctly retrieve the block_device information given the initial path which is a symlink.

Note: I saw that the tomoyo module has something like that but I was looking for the generic implementation of the kernel if one exists.

Thanks

David

David,

 

1 - Please read through: man 2 readlink ( yes please read it *all* very carefully !

2 - There is a system call readlink study it... 

     declared here: http://code.woboq.org/linux/include/unistd.h.html#809

     exported here: http://code.woboq.org/linux/linux/arch/um/os-Linux/user_syms.c.html#83

3  grep through the kernel and see where and how readlink is used.

    Try :   find . -name "*.[ch]" | xargs grep "readlink"

    and :   find . -name "*.[ch]" | xargs grep " readlink("

    and :   find . -name "*.[ch]" | xargs grep ">readlink"

4 - This will help you figure how to work things out use at your own risk :)

Good luck - Aruna

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