Which process accesses superblock?

lioryb · 11-27-2019, 02:25 AM

Hi.

While trying to make some changes in kernel sources for personal use, I noticed that there is a process/app that accesses the superblock in a point of time that I want to avoid that. It happens both on BOOT partition (FAT) and on rootfs partition (EXT).
I even tried walking through the kernel sources, adding prints in superblock write functions (fat_write_inode, for example), but I couldn't find the origin of the access.
How can I find out which process/app initiates the access?

syg00 · 11-27-2019, 07:12 PM

Linux now has a bunch of kernel tracing facilities - from perf and ftrace to bpf. Start with the first two, the learning curve will be lower.
As you're comfortable with the code and know your functions of interest history tracing might work best - maybe start here.