ubifs_pad(9)

✨ ubifs_pad ✨

okay so this is a page from the Kernel API Manual, bestie — we're deep in kernel land today 💅

🌸 NAME 🌸

ubifs_pad — pad flash space. that's it, that's the whole job 🎀

🦋 SYNOPSIS 🦋

void ubifs_pad (const struct ubifs_info *c , void *buf , int pad );

💖 ARGUMENTS 💖

• c — the UBIFS file-system description object, aka the main character of this entire operation 👑
• buf — the buffer where the padding gets dropped 🫶
• pad — literally how many bytes we're padding, no cap

🔥 DESCRIPTION 🔥

okay so here's the vibe: the flash media is very particular and obliges us to write only in chunks of c->min_io_size. so when we have to write less data than that, we add a padding node to the write-buffer and pad it out to the next minimal I/O unit's boundary. obsessed, honestly ✨

and like, the padding nodes are lowkey the heroes here — they help when the media is being scanned. 💀

but here's the thing: if the amount of wasted space is not enough to fit a padding node (which takes UBIFS_PAD_NODE_SZ bytes, not that anyone asked but slay), then we write the padding bytes pattern instead — that's UBIFS_PADDING_BYTE, iykyk 🌈

also! padding nodes are used to fill gaps when the "commit-in-gaps" method is used. multi-purpose icon 💅

🧚 SEE ALSO 🧚

kernel file ./fs/ubifs/io.c — go read it, it's giving main character energy 🍓

• ubifs_ro_mode(9)
• ubifs_check_node(9)
• next_sqnum(9)
• ubifs_prepare_node_hmac(9)
• ubifs_prepare_node(9)
• ubifs_prep_grp_node(9)
• wbuf_timer_callback_nolock(9)
• new_wbuf_timer_nolock(9)
• cancel_wbuf_timer_nolock(9)
• ubifs_wbuf_sync_nolock(9)
• ubifs_wbuf_seek_nolock(9)
• ubifs_bg_wbufs_sync(9)
• ubifs_wbuf_write_nolock(9)
• ubifs_write_node_hmac(9)
• ubifs_write_node(9)
• ubifs_read_node_wbuf(9)
• ubifs_read_node(9)
• ubifs_wbuf_init(9)
• ubifs_wbuf_add_ino_nolock(9)
• wbuf_has_ino(9)
• ubifs_sync_wbufs_by_inode(9)

and that's the whole page, bestie — thanks for reading 🫶 this one came from ./fs/ubifs and it's dated October 2026, so jot that down in ur notes app 📝💜