gfs2_trans_da_blks(9)

📦 version 7.3.1, in nixpkgs unstable

💫 gfs2_trans_da_blks — the Kernel API Manual page, bestie edition ✨

okay so you're here for gfs2_trans_da_blks(9) from the Kernel API Manual — that's the manpage name, hi, welcome, come sit with me 💖 This is the one that does the math on how many blocks you gotta reserve. Let's get into it.

🌸 NAME 🌸

gfs2_trans_da_blks — calculate number of blocks to link inode. that's it, that's the whole vibe 🎀

🦋 SYNOPSIS 🦋

unsigned gfs2_trans_da_blks (const struct gfs2_inode *dip , const struct
       gfs2_diradd *da , unsigned nr_inodes );

it returns an unsigned, it takes three args, and yes you gotta write struct every time, that's just how C is, no cap ✨

💅 ARGUMENTS 💅

  • dip — the directory we are linking into 🏠 she's the destination, the main character of this operation, lowkey.
  • da — the dir add information 📋 that's the struct carrying the add details, k? k.
  • nr_inodes — the number of inodes involved 👯 how many little guys are in the mix. iykyk.

🧚 DESCRIPTION 🧚

okay so the way that this works: this calculates the number of blocks we need to reserve in a transaction so we can link nr_inodes into a directory 💫 it's giving "do the accounting before you commit," which is honestly iconic of her.

in most cases nr_inodes will be 2 — that's the directory plus the inode being linked in, the classic pair, the duo, the bestie system 🫶 — but in case of rename, 4 may be required 😭 (yes, rename is highkey extra, it's got more moving parts, we still love her).

👑 RETURN 👑

Number of blocks 🔥 that's the return value. you asked how many blocks, she tells you how many blocks. periodt.

🌈 SEE ALSO 🌈

Kernel file ./fs/gfs2/inode.c — and like, all of these, go read them, they're all linked in the source:

ok that's the whole page bestie, no notes 💜 go reserve your blocks responsibly.

and that's a wrap on gfs2_trans_da_blks(9) 🎀 brought to you from ./fs/gfs2, dated October 2026 — mwah, love u, bye 💋✨

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