STRUCT NILFS_BMAP(9)

💖 struct nilfs_bmap(9) 💖

okay so welcome to the struct nilfs_bmap(9) page — that's the section 9 entry in the Kernel API Manual, bestie, and we're about to get so cozy with a bmap structure 🎀

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✨ NAME ✨

struct nilfs_bmap — the bmap structure itself, no cap, that's literally it 🦋

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🌸 SYNOPSIS 🌸

struct nilfs_bmap {
    union {
      __u8 u_flags;
      __le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
    } b_u;
    struct rw_semaphore b_sem;
    struct inode *b_inode;
    const struct nilfs_bmap_operations *b_ops;
    __u64 b_last_allocated_key;
    __u64 b_last_allocated_ptr;
    int b_ptr_type;
    int b_state;
    __u16 b_nchildren_per_block;
 };

like, look at her. main character struct energy. copy it exactly, don't you dare retype a field name wrong 💅

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🧚 Members 🧚

okay bestie, let's go field by field, one at a time, no skipping 🔥

• b_u — raw data, the whole vibe, unfiltered 🙈
• b_sem — a semaphore, she's the bouncer at the door 💀
• b_inode — the owner of the bmap, iykyk 👑
• b_ops — the bmap operation table, the whole playbook fr fr 📖
• b_last_allocated_key — the last allocated key for a data block, she remembers 🌸
• b_last_allocated_ptr — the last allocated ptr for a data block, also remembered 🫶
• b_ptr_type — pointer type ⭐
• b_state — state, that's the whole description, that's the tweet 🐦
• b_nchildren_per_block — maximum number of child nodes for non-root nodes — note the non-root part, that's load-bearing 🧠

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🌈 SEE ALSO 🌈

go read these next, bestie, they're all connected:

• Kernel file ./fs/nilfs2/bmap.h
• union nilfs_bmap_ptr_req(9)
• struct nilfs_bmap_stats(9)
• struct nilfs_bmap_operations(9)
• struct nilfs_bmap_store(9)

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lowkey a little reminder: everything above is exactly what the page says, so don't go inventing behaviour for these fields, mwah 🫶

and that's the whole page!! ate and left no crumbs 💅✨ — this one's from ./fs/nilfs2, dated October 2026, and yeah, it's the struct nilfs_bmap(9) page, iconic, periodt 💖