nommu_shrink_inode_mappings(9)

💅 nommu_shrink_inode_mappings(9)

okay so bestie, welcome to the Kernel API Manual ✨ this one's a whole function, and she's got a big job: shrinking shared mappings on an inode without breaking anyone's vibe. let's get into it 🫶

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🌸 NAME 🌸

nommu_shrink_inode_mappings — literally shrinks the shared mappings on an inode 💫

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✨ SYNOPSIS ✨

int nommu_shrink_inode_mappings (struct inode *inode , size_t size ,
       size_t newsize );

the way she takes three arguments and returns an int… main character energy fr fr 👑

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🎀 ARGUMENTS 🎀

• inode — the inode to check 👀 that's the one we're doing a vibe check on
• size — the current filesize of the inode, like right now, as it stands
• newsize — the proposed filesize of the inode, aka where we're tryna take her

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🦋 DESCRIPTION 🦋

so here's the tea ☕ this function checks the shared mappings on an inode on behalf of a shrinking truncate — and the whole point is making sure that any outstanding VMAs aren't broken 😭 like, not on our watch.

then it shrinks the vm_regions that extend beyond, so that do_mmap doesn't automatically grant mappings that are too large. no cap, that's the entire assignment 💅

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🌈 SEE ALSO 🌈

• Kernel file ./mm/nommu.c 📁
• vmalloc_node(9)
• vzalloc_node(9)
• vmalloc_32(9)
• vmalloc_32_user(9)
• access_remote_vm(9)
• copy_remote_vm_str(9)

go read those next, iykyk 🧚

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okay that's the whole page bestie, you ate that 🍓 mwah 💖

sign-off szn: this lil masterpiece lives over in ./mm, dated October 2026, and it's filed under nommu_shrink_inode_mappings(9) ⭐ periodt 💜