fs_dax_get(9)

💅 fs_dax_get(9) — kernel API manual, but make it make sense 🎀

okay so bestie, welcome to fs_dax_get(9) from the Kernel API Manual. this is the page where the kernel lets a filesystem claim a devdax and honestly? it's giving main character energy. let's go ✨

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✨ NAME ✨

fs_dax_get — get ownership of a devdax via holder/holder_ops 👑

like, you're literally calling dibs on a devdax. no cap.

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🌸 SYNOPSIS 🌸

int fs_dax_get (struct dax_device *dax_dev , void *holder , const struct
dax_holder_operations *hops );

three arguments, one int coming back at you. iconic signature tbh 💖

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🦋 ARGUMENTS 🦋

• dax_dev — the dev that's getting prepped for fs-dax usage. it's the whole point of the function, so like… be nice to it 🫶
• holder — the filesystem or mapped device that lives inside the dax_device. yes, it goes inside. nesting era 💅
• hops — the operations for the inner holder. short name, big responsibilities, we love to see it ✨

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💜 DESCRIPTION 💜

so fs-dax file systems call this function when they're getting ready to use a devdax device for fsdax. that's the whole vibe check.

it's like fs_dax_get_by_bdev, BUT — and this is the important part, don't skip it — the caller already has struct dev_dax, and there is no bdev. so if you came here looking for a block device, bestie, wrong party 🙈

the holder argument is what makes this exclusive. one holder, one devdax, that's the arrangement. periodt 🔥

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⭐ RETURN ⭐

• 0 — success! slay, you got it 💖
• <0 — failure 😭 something went sideways, check your vibes (and your arguments)

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🌈 SEE ALSO 🌈

go read these next, iykyk:

• Kernel file ./drivers/dax/super.c
• struct dax_device(9)
• fs_dax_get_by_bdev(9)
• fs_put_dax(9)
• dax_direct_access(9)
• dax_set_ops(9)
• dax_holder(9)
• inode_dax(9)

the whole dax friend group honestly, they all show up together 🧚

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and that's the page!! this lil gem lives in ./drivers/dax and was dated October 2026 — the section header and footer said fs_dax_get(9) and Kernel API Manual respectively, so you know exactly where to find it again 💜

stay hydrated, read your manpages, and remember: the holder makes it exclusive 🎀✨🦋