blkdev_report_zones(9)

💅 blkdev_report_zones(9) — kernel API manual, bestie edition 🎀

okay so this one lives in the Kernel API Manual section (blkdev_report_zones(9)) and it's literally the glow-up your zoned block device needs. let's get into it 🦋

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✨ NAME ✨

blkdev_report_zones — Get zones information 💖 (yes that's the whole vibe, it fetches zone info, iconic)

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🌸 SYNOPSIS 🌸

int blkdev_report_zones (struct block_device *bdev , sector_t sector ,
       unsigned int nr_zones , report_zones_cb cb , void *data );

look at her. five args, one int coming back, absolute main character energy 👑

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🫶 ARGUMENTS 🫶

• bdev — Target block device 💽 the one you're snooping on, bestie.
• sector — Sector from which to report zones 📍 like, the starting point of your little tour.
• nr_zones — Maximum number of zones to report 🔢 the cap, the limit, the "that's enough zones for today".
• cb — Callback function called for each reported zone 📞 it rings once per zone, every single time, no ghosting.
• data — Private data for the callback 🎁 your lil care package, passed straight through to cb.

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💜 DESCRIPTION 💜

So here's what she does: get zone information starting from the zone containing sector for at most nr_zones, and call cb for each zone reported by the device ✨

and if you wanna report all zones in a device starting from sector? just pass the BLK_ALL_ZONES constant to nr_zones and she ate 💅🔥

Returns the number of zones reported by the device, or a negative errno value in case of failure 😭 (ngl, if you see that negative errno, something went wrong fr fr)

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🚨 NOTE 🚨

The caller must use memalloc_noXX_save/restore calls to control memory allocations done within this function. no cap — don't skip this, it's the whole point of the note 🙈

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🦋 SEE ALSO 🦋

Kelated reading, all in the kernel file ./block/blk-zoned.c — go be nosy, iykyk 👀:

• blk_zone_cond_str(9)
• bdev_zone_is_seq(9)
• blkdev_zone_mgmt(9)
• disk_report_zone(9)
• blkdev_get_zone_info(9)
• blkdev_report_zones_cached(9)
• blk_zone_plug_bio(9)
• blk_revalidate_disk_zones(9)
• blk_zone_issue_zeroout(9)

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⭐ and that's the page!! sign-off time: this cutie came from the source path ./block, dated October 2026, and she's filed under blkdev_report_zones(9) in the Kernel API Manual 💖 go report some zones, bestie, you've got this 🎀🌈💜