blkdev_report_zones_cached(9)

💖 blkdev_report_zones_cached — the Kernel API Manual, but make it cute 💖

okay so bestie, this is a page out of the Kernel API Manual, and honestly? it's a little banger. it's about grabbing your zone info without bothering the actual hardware — like checking the group chat instead of calling everyone individually. slay. 🎀

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✨ NAME ✨

blkdev_report_zones_cached — get cached zones information 🦋

like, the zones you already know about. from the cache. no cap.

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🌸 SYNOPSIS 🌸

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

that's the whole vibe check: it hands you back an int, takes a block device, a sector, a zone count, a callback, and some private data. five things. we love a clean signature. 💅

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🫶 ARGUMENTS 🫶

• bdev — the target block device 💿 like, the one you're actually curious about.
• sector — the sector you wanna start reporting zones from. your little starting point. 📍
• nr_zones — the maximum number of zones to report. it's a cap, not a promise, bestie. 🧢
• cb — the callback function, called for each reported zone. one zone, one call, every time. 🔁
• data — private data for the callback function. your little stash of stuff to pass along. 🙈

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🔥 DESCRIPTION 🔥

okay so this one is similar to blkdev_report_zones BUT — and this is the whole point — instead of calling into the low level device driver to get the zone report from the device, it uses blkdev_get_zone_info to generate the report from the disk zone write plugs and zones condition array. 🧚✨

basically: no device driver gossip, we're just reading what we already wrote down. iconic behaviour, honestly.

⚠️ heads up! since calling this function without a callback does not make sense, cb must be specified. not optional. not "i'll add it later". must. periodt. 💀

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👑 SEE ALSO 👑

go read these next, i'm obsessed with all of them:

• ./block/blk-zoned.c — kernel file, the mothership 🏠
• blk_zone_cond_str(9) — zone condition, but as a string 🌈
• bdev_zone_is_seq(9) — is this zone sequential? 👀
• blkdev_report_zones(9) — the non-cached cousin ⭐
• blkdev_zone_mgmt(9) — zone management duties 🛠️
• disk_report_zone(9) — the disk's own report 🗂️
• blkdev_get_zone_info(9) — where the cached info comes from 🔍
• blk_zone_plug_bio(9) — plug that bio, bestie 🔌
• blk_revalidate_disk_zones(9) — revalidate all the things ✅
• blk_zone_issue_zeroout(9) — zero it out 💨

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and that's the page!! 🦋💖 this little gem comes to you from ./block, dated October 2026, straight out of the Kernel API Manual. mwah. take care of her. 🎀✨💅