ecryptfs_write_begin(9)

✨ ecryptfs_write_begin ✨

okay so bestie, welcome to the ecryptfs_write_begin page 💅 this one lives in section 9 of the Kernel API Manual, and it's genuinely short and sweet — like, a snack-sized manpage, no cap 🍓

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🌸 SYNOPSIS 🌸

int ecryptfs_write_begin (const struct kiocb *iocb , struct
       address_space *mapping , loff_t pos , unsigned len , struct folio
       **foliop , void **fsdata );

it returns an int, and bestie, that int is the whole vibe check of the call 👑

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🦋 ARGUMENTS 🦋

• iocb — the I/O control block for the eCryptfs file 🔥 that's the thing telling you which file we're doing business with.
• mapping — the eCryptfs object, aka the address space we're working in.
• pos — the file offset where the writing starts, like the little bookmark of where we begin ✨
• len — how long the write is. length girlies rise 🙈
• foliop — a pointer to return the folio 📄 (yes, the folio comes back through here, that's the whole point)
• fsdata — a pointer to return fs data, and ngl it's marked unused 💀 so it's giving decorative, but it's still there, keep it.

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💜 DESCRIPTION 💜

okay so the one thing this function is out here to do: this function must zero any hole we create 🫶 that's the moment. that's the assignment. no skipping it, fr fr.

Returns zero on success; non-zero otherwise — so 0 is the slay outcome, and anything else means something went sideways 😭

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🧚 SEE ALSO 🧚

• Kernel file ./fs/ecryptfs/mmap.c — go read it, iykyk 📖
• ecryptfs_copy_up_encrypted_with_header(9)
• ecryptfs_read_folio(9)
• ecryptfs_write_end(9)

like, read the whole little friend group, they all hang out together 🌈

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bestie reminder: the "must zero any hole we create" line isn't a suggestion, it's the actual contract. treat it with main character energy ✨

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mwah 💖 that's the whole page! this one came from the ./fs/ecryptfs corner of the kernel, dated October 2026, and it's filed under ecryptfs_write_begin(9) in the Kernel API Manual — go forth and write your encrypted writes, queen 👑🎀