drbd_contains_interval(9)

💖 drbd_contains_interval(9) 💖

okay so bestie, welcome to the Kernel API Manual, section 9 — this is the page for drbd_contains_interval, and it's genuinely such a vibe. it's a little helper that just wants to know: is this interval in this tree or not? 🎀 let's get into it.

---

✨ SYNOPSIS ✨

bool drbd_contains_interval (struct rb_root *root , sector_t sector ,
       struct drbd_interval *interval );

like, that's the whole call. it hands you back a bool and you can go about your day. 🦋

---

🌸 ARGUMENTS 🌸

• root — the red black tree root 🌳 that's your starting point, the whole tree lives under here
• sector — the start sector of the interval 🧚 you're asking about, sector_t flavoured
• interval — and here's the spicy bit 🔥: this one may be an invalid pointer. like, unhinged but true. it might not be a real thing at all, so don't go assuming

---

💅 DESCRIPTION 💅

so what does it actually do? it returns whether the tree contains the node interval with start sector sector. that's the whole question, that's the assignment. 👑

and the way it's careful with interval? iconic, honestly. it does not dereference interval until interval is known to be a valid object in the tree. so it's not gonna just yolo-read from a pointer that might be garbage — no cap, it checks first. 🫶

one more little detail so you're not caught off guard: it returns false if interval is in the tree but with a different sector number. so like, present ≠ matching, iykyk. 😭 it's gotta be the right node and the right sector.

lowkey the moral of the story is: this function is safe to call with a sketchy interval pointer and it will not dereference it unless it's already confirmed valid in the tree. periodt. 💀

---

🌈 SEE ALSO 🌈

• the kernel file ./drivers/block/drbd/drbd_interval.c — go read the source, it's right there 📂
• drbd_find_overlap(9) — the other interval bestie, go say hi ⭐

---

and that's the page, diva 🧚💜 — this one came to you from ./drivers/block/drbd, dated October 2026, so go forth and check your intervals with confidence. slay. 💅✨🍓