switch_gc_head(9)

💅 switch_gc_head(9) — the kernel API manual, bestie edition

okay so this is switch_gc_head, from section 9 of the manual (kernel API, iykyk). it's a lil function in UBIFS land and honestly it's giving "quietly important." let's get into it 🫶

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✨ NAME ✨

switch_gc_head — switch the garbage collection journal head. that's it, that's the whole vibe. the GC journal head? switched. 💅

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✨ SYNOPSIS ✨

int switch_gc_head (struct ubifs_info *c );

literally one argument, no drama, no cap.

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✨ ARGUMENTS ✨

• c — the UBIFS file-system description object. your whole file-system situation lives in here, bestie 🌸

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✨ DESCRIPTION ✨

so what this function actually does: it switches the GC head over to the next LEB — and that LEB is the one reserved in c->gc_lnum. that's the spot. that's the destination. no detours 💫

then it tells you how it went:

• it returns 0 in case of success — slay, we love a clean win ✨
• it returns -EAGAIN if a commit is required — so like, "not right now, we need a commit first" 🙈
• and it returns other negative error codes in case of failures — yeah those happen 😭

ngl, check the return value. -EAGAIN is not a fail, it's a "come back after the commit," and the other negative codes are the actual failures. keep those two vibes separate 🎀

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✨ SEE ALSO ✨

the kernel file ./fs/ubifs/gc.c is the main character here 👑 and these functions are all in the group chat:

• data_nodes_cmp(9)
• sort_nodes(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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🌈 the sign-off 🌈

this page lives in ./fs/ubifs, and it's dated October 2026 — future-coded of it, honestly 🦋 and the page itself is switch_gc_head(9), which you already knew because i told you up top 💜

go forth and switch that GC head, bestie. periodt. 💅✨