sort_nodes(9)

✨ sort_nodes(9) — the UBIFS glow-up 💅

okay so real talk, bestie: this is a Kernel API Manual page for sort_nodes, and it is genuinely the main character of garbage collection in UBIFS. It's the function that literally sorts your nodes so GC doesn't have to be messy. no cap. 🎀

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🌸 NAME 🌸

sort_nodes — sort nodes for GC. that's it, that's the vibe. ✨

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🦋 SYNOPSIS 🦋

int sort_nodes (struct ubifs_info *c , struct ubifs_scan_leb *sleb ,
struct list_head *nondata , int *min );

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💖 ARGUMENTS 💖

• c — the UBIFS file-system description object. your whole file-system situation, basically. 🫶
• sleb — describes the nodes to sort, and on exit it's holding the result. so it comes in describing, goes out serving. 💅
• nondata — on exit this contains the non-data nodes. that's the whole job. ✨
• min — the minimum node size gets returned right here. cute little out-param. 🎀

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🔥 DESCRIPTION 🔥

okay so this function sorts the list of inodes to garbage collect. that's the mission. 🫡

First of all, it kills obsolete nodes (💀 bye bestie) and separates data and non-data nodes off into the sleb->nodes and nondata lists correspondingly.

Then the data nodes get sorted in block number order — and this is important for bulk-read, iykyk. the rules are:

• data nodes with lower inode number go before data nodes with higher inode number ✅
• data nodes with lower block number go before data nodes with higher block number ✅

Non-data nodes get sorted like this:

• first go inode nodes — they're sorted in descending length order 📏
• then go directory entry nodes — they're sorted in hash order, which should supposedly optimize 'readdir'. and specifically:
  • direntry nodes with lower parent inode number go before direntry nodes with higher parent inode number 👑
  • direntry nodes with lower name hash values go before direntry nodes with higher name hash values 👑

This function returns zero in case of success and a negative error code in case of failure. no in-between, no drama (well, the negative error code is the drama 😭).

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🌈 SEE ALSO 🌈

Kernel file ./fs/ubifs/gc.c and its whole friend group, fr fr:

• switch_gc_head(9)
• data_nodes_cmp(9)
• move_node(9)
• move_nodes(9)
• gc_sync_wbufs(9)
• ubifs_garbage_collect_leb(9)
• ubifs_garbage_collect(9)
• ubifs_gc_start_commit(9)
• ubifs_gc_end_commit(9)
• ubifs_destroy_idx_gc(9)
• ubifs_get_idx_gc_leb(9)

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💡 friendly reminder: this page lives under ./fs/ubifs, and it's the October 2026 vintage. slay.

and that's the whole page, bestie — go forth and sort responsibly. 🧚💜