ecryptfs_write(9)

💖 NAME 💖

okay bestie, welcome to ecryptfs_write(9), straight from the Kernel API Manual — kernel-space bestie check, we are so back ✨

ecryptfs_write -

that's the whole NAME line — no extra tagline, she's lowkey mysterious like that 💅

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🦋 SYNOPSIS 🦋

int ecryptfs_write (struct inode *ecryptfs_inode , char *data , loff_t
offset , size_t size );

this is the exact signature, bestie — do not freestyle the spacing, she's particular ✨

🌸 ARGUMENTS 🌸

• ecryptfs_inode — the eCryptfs file into which to write. that's the target file, the main character of this whole write operation 👑
• data — virtual address where data to write is located. think: where your bytes are chilling before they get written 🫶
• offset — offset in the eCryptfs file at which to begin writing the data from data. it's literally the starting spot in the file 🌈
• size — the number of bytes to write from data. how many bytes you're bringing to the party 🎀

🔥 DESCRIPTION 🔥

okay so ecryptfs_write writes an arbitrary amount of data to an arbitrary location in the eCryptfs inode page cache. no cap, arbitrary amount, arbitrary location — she's flexible like that 💅

the way it does this is page-by-page, and then extent-by-extent. individual extents get encrypted and written to the lower page cache (via VFS writes). so yes, encryption is happening, and yes, it's giving layered filesystem realness 🔐✨

this function takes care of all the address translation to locations in the lower filesystem. she also handles truncate events, writing out zeros where necessary — very responsible, very iconic 🫶

return vibe check: 0 on success; non-zero otherwise 😭

🧚 SEE ALSO 🧚

• Kernel file ./fs/ecryptfs/read_write.c — the source file situation, go look 👀
• ecryptfs_write_lower(9)
• ecryptfs_write_lower_page_segment(9)
• ecryptfs_read_lower(9)
• ecryptfs_read_lower_page_segment(9)

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mwah 💋 sign-off time: source/version ./fs/ecryptfs, date October 2026, and the page is ecryptfs_write(9) — byeeee, go write some encrypted bytes responsibly 🫶✨