dbg_walk_index(9)

💅 dbg_walk_index(9) — like, the UBIFS index walker, bestie

okay so real talk, this page lives in the Kernel API Manual (section 9, kernel-space tea ☕) and it's all about dbg_walk_index. come sit, I'll hype you up on what it does 🫶

---

✨ NAME ✨

dbg_walk_index — walk the on-flash index. that's it, that's the vibe. no cap. 🚶‍♀️💫

---

🌸 SYNOPSIS 🌸

int dbg_walk_index (struct ubifs_info *c , dbg_leaf_callback leaf_cb ,
dbg_znode_callback znode_cb , void *priv );

literally the whole signature, character for character, don't @ me. returns an int, takes four things. iconic. 👑

---

🎀 ARGUMENTS 🎀

• c — the UBIFS file-system description object. it's giving "context", it's giving "everything you need to know about this fs". 💖
• leaf_cb — this one gets called for each leaf node. every single one, bestie. 🌿
• znode_cb — and this one gets called for each indexing node. different callback, different job, both invited to the party. 🦋
• priv — your private data, which gets passed straight through to the callbacks. like a little goodie bag you hand to both of them. 🎁

---

🔥 DESCRIPTION 🔥

So what does this thing actually do? It walks the UBIFS index, and along the way it calls leaf_cb for each leaf node and znode_cb for each indexing node. that's the whole loop, and honestly? obsessed. 💅

It returns zero in case of success — and a negative error code in case of failure. so like, 0 = slay, negative = 😭.

heads-up, and this is straight from the source, not me being dramatic: it would be better if this function removed every znode it pulled into the TNC, so that the behavior more closely matched the non-debugging behavior. so yeah, lowkey a known "could be better" situation. noted. 🫡

---

🌈 SEE ALSO 🌈

the whole friend group, and yes I'm listing every single one because nobody gets left out:

• Kernel file ./fs/ubifs/debug.c — ubifs_dump_index(9)
• dbg_save_space_info(9)
• dbg_check_space_info(9)
• dbg_check_synced_i_size(9)
• dbg_check_key_order(9)
• dbg_check_znode(9)
• dbg_check_tnc(9)
• add_size(9)
• dbg_check_idx_size(9)
• struct fsck_inode(9)
• struct fsck_data(9)
• add_inode(9)
• search_inode(9)
• read_add_inode(9)
• check_leaf(9)
• free_inodes(9)
• check_inodes(9)
• dbg_check_filesystem(9)
• dbg_check_data_nodes_order(9)
• dbg_check_nondata_nodes_order(9)
• provide_user_output(9)
• interpret_user_input(9)
• dbg_debugfs_init_fs(9)
• dbg_debugfs_exit_fs(9)
• dbg_debugfs_init(9)
• dbg_debugfs_exit(9)
• ubifs_debugging_init(9)
• ubifs_debugging_exit(9)

---

and that's the page!! 💜 shoutout to the fine folks over at ./fs/ubifs for this one, dated October 2026 — go read the source, it's giving main character energy, iykyk ✨🧚