write_ecryptfs_marker(9)

💅 write_ecryptfs_marker(9) — a Kernel API Manual moment 🎀

ok so this is from the Kernel API Manual, bestie, and it's literally the tiniest little function in eCryptfs. It stamps a magic number into a page. That's it. That's the whole gig. And honestly? Iconic. Let's get into it ✨

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🌸 NAME 🌸

write_ecryptfs_marker —

and that's it. The dash is just... there. Hanging out. No description. Nothing after it. The manpage literally gave us the function name and then ✨ nothing ✨ and honestly? Respect the mystery. The DESCRIPTION has to do all the heavy lifting around here 🫶

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✨ SYNOPSIS ✨

void write_ecryptfs_marker (char *page_virt , size_t *written );

no return value, she's a void girlie, she just goes in and does the thing 💅

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🦋 ARGUMENTS 🦋

• page_virt — the pointer into a page where you wanna start writing the marker. Like, where in the page the magic begins. You pick the spot, she fills it in 💖
• written — number of bytes written. She reports back. You hand her the size_t * and she tells you how much she wrote. Communication queen 👑

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🔥 DESCRIPTION 🔥

so the whole entire vibe of this function is:

Marker = 0x3c81b7f5

that's it. that's the description. she writes 0x3c81b7f5 into the page and dips. no cap, that's the entire documented behaviour. a whole function dedicated to one hex constant and I kind of love that for her 😭

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⭐ SEE ALSO ⭐

okay this is the part where the manpage really popped off, because the list is LONG and everyone's invited. From the kernel file ./fs/ecryptfs/crypto.c we have, in order, no skips, no cuts:

• ecryptfs_from_hex(9)
• ecryptfs_derive_iv(9)
• ecryptfs_init_crypt_stat(9)
• ecryptfs_destroy_crypt_stat(9)
• virt_to_scatterlist(9)
• crypt_scatterlist(9)
• crypt_extent(9)
• ecryptfs_encrypt_page(9)
• ecryptfs_decrypt_page(9)
• ecryptfs_init_crypt_ctx(9)
• ecryptfs_copy_mount_wide_flags_to_inode_flags(9)
• ecryptfs_set_default_crypt_stat_vals(9)
• ecryptfs_new_file_context(9)
• ecryptfs_validate_marker(9)
• ecryptfs_process_flags(9)
• ecryptfs_code_for_cipher_string(9)
• ecryptfs_cipher_code_to_string(9)
• ecryptfs_write_headers_virt(9)
• ecryptfs_write_metadata(9)
• set_default_header_data(9)
• ecryptfs_read_headers_virt(9)
• ecryptfs_read_xattr_region(9)
• ecryptfs_process_key_cipher(9)
• ecryptfs_destroy_crypto(9)
• ecryptfs_tfm_exists(9)
• ecryptfs_get_tfm_and_mutex_for_cipher_name(9)
• ecryptfs_encode_for_filename(9)
• ecryptfs_decode_from_filename(9)
• ecryptfs_encrypt_and_encode_filename(9)
• ecryptfs_decode_and_decrypt_filename(9)

thirty entries. thirty!! 💀 the whole crypto squad showed up to the group chat. ecryptfs_validate_marker(9) is lowkey her bestie since it's the one that checks what she wrote, iykyk 🧚

no warnings, no bugs, no exit statuses listed here — this page is short and sweet and has zero drama. keep it that way 🌈

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anyway bestie that's the whole page!! tiny function, big energy, one hex constant carrying the entire DESRIPTION section on her back 💜

from the fine folks over in ./fs/ecryptfs, dated October 2026 — catch you in the next manpage, mwah 🍓🎀💖