STRUCT UBIFS_INO_NODE(9)

💅 struct ubifs_ino_node(9) — the inode node, bestie

okay so real talk, we're deep in the kernel API manual rn (Kernel API Manual, to be exact) and today's main character is struct ubifs_ino_node — the inode node. yes THE inode node. it's giving "I hold everything you need to know about a file" energy and honestly? iconic. 🎀

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✨ NAME ✨

struct ubifs_ino_node — inode node. that's it, that's the vibe. 🦋

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🌸 SYNOPSIS 🌸

struct ubifs_ino_node {
    struct ubifs_ch ch;
    __u8 key[UBIFS_MAX_KEY_LEN];
    __le64 creat_sqnum;
    __le64 size;
    __le64 atime_sec;
    __le64 ctime_sec;
    __le64 mtime_sec;
    __le32 atime_nsec;
    __le32 ctime_nsec;
    __le32 mtime_nsec;
    __le32 nlink;
    __le32 uid;
    __le32 gid;
    __le32 mode;
    __le32 flags;
    __le32 data_len;
    __le32 xattr_cnt;
    __le32 xattr_size;
    __u8 padding1[4];
    __le32 xattr_names;
    __le16 compr_type;
    __u8 padding2[26];
    __u8 data[];
};

look at her. she's structured. she's aligned. she's literally the blueprint. 💅

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👑 Members 👑

• ch — the common header. every node's lil hello.
• key — the node key, fr fr your lookup bff.
• creat_sqnum — sequence number at time of creation. the birth certificate timestamp. 😭
• size — inode size in bytes (amount of uncompressed data). note: uncompressed, okay? don't come for me.
• atime_sec — access time seconds.
• ctime_sec — creation time seconds.
• mtime_sec — modification time seconds.
• atime_nsec — access time nanoseconds. precision era ✨
• ctime_nsec — creation time nanoseconds.
• mtime_nsec — modification time nanoseconds.
• nlink — number of hard links. how many besties point at you.
• uid — owner ID.
• gid — group ID.
• mode — access flags.
• flags — per-inode flags (UBIFS_COMPR_FL, UBIFS_SYNC_FL, etc). the personality traits.
• data_len — inode data length.
• xattr_cnt — count of extended attributes this inode has.
• xattr_size — summarized size of all extended attributes in bytes.
• padding1 — reserved for future, zeroes. it's a placeholder bestie, leave her alone 🫶
• xattr_names — sum of lengths of all extended attribute names belonging to this inode.
• compr_type — compression type used for this inode.
• padding2 — reserved for future, zeroes. same deal. 🫶
• data — data attached to the inode. the actual content, the payload, the lore.

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🦋 Description 🦋

okay so important thing number one: even though the inode compression type is defined by compr_type, some nodes of this inode may be compressed with a different compressor. and why, you ask? it happens if the compression type is changed while the inode already has data nodes. messy, i know, but that's the situation 😭. but compr_type will be used for further writes to the inode. so like, going forward, that's the one. periodt.

⚠️ important thing number two, do NOT forget: amend 'zero_ino_node_unused' when you're changing the padding fields. that function is NOT about to be left on read. no cap. 💀

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💜 SEE ALSO 💜

Kernel file ./fs/ubifs/ubifs-media.h and the whole friend group:

• struct ubifs_ch(9)
• union ubifs_dev_desc(9)
• struct ubifs_dent_node(9)
• struct ubifs_data_node(9)
• struct ubifs_trun_node(9)
• struct ubifs_pad_node(9)
• struct ubifs_sb_node(9)
• struct ubifs_mst_node(9)
• struct ubifs_ref_node(9)
• struct ubifs_auth_node(9)
• struct ubifs_sig_node(9)
• struct ubifs_branch(9)
• struct ubifs_idx_node(9)
• struct ubifs_cs_node(9)
• struct ubifs_orph_node(9)

go read them. they ate. 🔥

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and that's the whole page, bestie — sobbing, screaming, throwing up (./fs/ubifs, dated October 2026), brought to you by the same folks who gave you struct ubifs_ino_node(9). mwah 💋✨🌈