disk_openers(9)

💖 NAME 💖

okay so bestie, this is disk_openers(9) from the Kernel API Manual (section 9), and it does exactly what it says on the tin: returns how many openers are there for a disk. no cap, that's the whole gig. 💅

✨ SYNOPSIS ✨

unsigned int disk_openers (struct gendisk *disk );

🎀 ARGUMENTS 🎀

• disk — the disk to check, bestie 🫶

🦋 DESCRIPTION 🦋

This returns the number of openers for a disk. Note that this value is only stable if disk->open_mutex is held. so like, if you need the number to actually stay put and mean something, hold that mutex, periodt. 🔥

💀 NOTE 💀

⚠️ due to a quirk in the block layer open code, each open partition is only counted once even if there are multiple openers. iykyk — that's the quirk, and it's giving “counted once, not per-opener” energy. 😭

🌈 SEE ALSO 🌈

• Kernel file ./include/linux/blkdev.h genhd capability flags(9)
• disk_has_partscan(9)
• bio_needs_zone_write_plugging(9)
• disk_zone_capacity(9)
• blk_alloc_disk(9)
• queue_limits_start_update(9)
• queue_limits_cancel_update(9)
• bio_end_io_acct(9)

xoxo, source/version: ./include/linux, dated October 2026, page: disk_openers(9) — mwah 💋✨