bdev_mark_dead(9)

💀 bdev_mark_dead — bestie, we gotta talk

okay so real talk: this is a page from the Kernel API Manual, section 9, all about bdev_mark_dead. yes, that name is exactly as dramatic as it sounds. no cap. 🫶

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✨ NAME ✨

bdev_mark_dead — mark a block device as dead 💀

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🎀 SYNOPSIS 🎀

void bdev_mark_dead (struct block_device *bdev , bool surprise );

that's it. that's the whole signature. two args, zero returns, one vibe check. 🌸

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🦋 ARGUMENTS 🦋

• bdev — the block device we're operating on, aka the main character of this whole situation 👑
• surprise — a bool that says whether this is a surprise removal (like... are we telling everyone the bad news, or did they already find out 😭)

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💅 DESCRIPTION 💅

so the whole point of this function is literally just: tell the file system that this device (or its media) is dead. that's the job. that's the assignment. periodt.

now the surprise flag is doing a lot of heavy lifting:

• if surprise is set to true → the device or media is already gone. like, gone gone. it's giving "no warning, just vibes" 💀
• if not → we're just preparing for an orderly removal. civilised. planned. we seen it coming ✨

and here's the tea 🍵 — this function calls into the file system, which then typically:

1. syncs out all the dirty data 🔥
2. writes back the inodes 🎀
3. invalidates any cached data in the inodes on the file system 🧹

and in addition to all that, we also invalidate the block device mapping. love that for us. 🦋

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💜 SEE ALSO 💜

• Kernel file ./block/bdev.c
• bdev_validate_blocksize(9)
• bdev_freeze(9)
• bdev_thaw(9)
• bdev_deny_freeze(9)
• bdev_allow_freeze(9)
• bd_may_claim(9)
• bd_prepare_to_claim(9)
• bd_finish_claiming(9)
• bd_abort_claiming(9)
• bdev_open(9)
• bdev_yield_claim(9)
• bdev_fput(9)
• lookup_bdev(9)

like... the whole friend group is here. iykyk 🫶

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okay that's the page!! mwah 💖 this beauty lives in ./block, it's dated October 2026, and the whole thing is filed under bdev_mark_dead(9) — go read the source bestie, slay 🧚💅