is_valid_transition(9)

🎀 NAME 🎀

okay so bestie, welcome to is_valid_transition(9), fresh from the Kernel API Manual ✨ This one is lowkey the vibe-check for DRBD state changes, and it's giving “nope, not today” energy 💅

is_valid_transition returns an SS_ error code if the state transition is not possible. It limits hard state transitions. Hard state transitions are facts imposed on DRBD by the environment — e.g. the disk broke or the network broke down 😭. But those hard state transitions are still not allowed to do everything, periodt.

📜 SYNOPSIS 📜

enum drbd_state_rv is_valid_transition (union drbd_state os , union drbd_state ns );

🧸 ARGUMENTS 🧸

• os — old state, aka the state you're coming from 👀
• ns — new state, aka the state you're trying to slide into ✨

🔗 SEE ALSO 🔗

• Kernel file ./drivers/block/drbd/drbd_state.c
• cl_wide_st_chg(9)
• drbd_force_state(9)
• drbd_req_state(9)
• _drbd_request_state(9)
• is_valid_state(9)
• is_valid_soft_transition(9)
• sanitize_state(9)
• _drbd_set_state(9)
• after_state_ch(9)

xoxo, this iconic page comes from source/version ./drivers/block/drbd and is dated October 2026 💜🫶