mark_buffer_dirty(9)

💖 mark_buffer_dirty(9) 💖

okay so welcome to the mark_buffer_dirty page, bestie — it lives in the Kernel API Manual and it's genuinely one of those little functions that keeps the whole filesystem from gaslighting itself. let's get into it 🫶

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✨ NAME ✨

mark_buffer_dirty — mark a buffer_head as needing writeout 🔥

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🌸 SYNOPSIS 🌸

void mark_buffer_dirty (struct buffer_head *bh );

that's it. that's the whole vibe. one arg, no return, no drama. 💅

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🎀 ARGUMENTS 🎀

• bh — the buffer_head to mark dirty. this is your main character right here 👑

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🦋 DESCRIPTION 🦋

okay so here's the whole little ritual, and it happens in order so pay attention:

mark_buffer_dirty will set the dirty bit against the buffer, then set its backing page dirty, then tag the page as dirty in the page cache, and then attach the address_space's inode to its superblock's dirty inode list. like, it's a whole four-step glow-up for that buffer ✨

lowkey important: mark_buffer_dirty is atomic. no cap. it takes bh->b_folio->mapping->i_private_lock, the i_pages lock, and mapping->host->i_lock.

three locks. three. she's holding all of them at once, so respect the icon and don't do anything goofy in there, iykyk 😭

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🌈 SEE ALSO 🌈

Kernel file ./fs/buffer.c

• bio_endio_bh(9)
• end_buffer_read_sync(9)
• bh_end_read(9)
• bh_end_write(9)
• bh_end_async_write(9)
• mmb_sync(9)
• block_dirty_folio(9)
• __brelse(9)
• __bforget(9)
• bh_submit(9)
• bdev_getblk(9)
• __bread_gfp(9)
• block_invalidate_folio(9)
• clean_bdev_aliases(9)
• try_to_free_buffers(9)
• bh_uptodate_or_lock(9)
• __bh_read(9)
• __bh_read_batch(9)

like a whole group chat of buffer functions, honestly. go read them all 💜

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and that's the page, bestie 🧚 this one came out of ./fs in October 2026, so if the date or the source ever changes, that's the version you're looking at. slay, bye 💖🎀🦋