writeback_inodes_sb_nr(9)

💅 writeback_inodes_sb_nr(9) — like, the Kernel API Manual, bestie

okay so this is writeback_inodes_sb_nr from the kernel API manual, and we're gonna get into it ✨ no cap.

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🌸 NAME 🌸

writeback_inodes_sb_nr — writeback dirty inodes from a given super_block. that's the whole vibe, that's the assignment 💖

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🎀 SYNOPSIS 🎀

void writeback_inodes_sb_nr (struct super_block *sb , unsigned long nr ,
enum wb_reason reason );

like, look at her. iconic signature. no notes 👑

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🦋 ARGUMENTS 🦋

• sb — the superblock. the main character of this whole situation, fr fr.
• nr — the number of pages to write. that's the ask, that's the dream 💫
• reason — the reason why some writeback work got initiated. yes we're documenting the why, we're being thorough, we're that girl 🫶

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✨ DESCRIPTION ✨

so basically you start writeback on some inodes on this super_block. and like — and this is the important part, bestie, don't skip it — no guarantees are made on how many (if any) will be written. could be a lot, could be zero, could be a whole vibe. 🙈 and ALSO, this function does not wait for IO completion of submitted IO. it sends it and dips. it's giving "I said what I said" energy 💅

lowkey important: it's fire-and-forget. do not assume anything actually got written, and do not assume anything is done when it returns. periodt.

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🌈 SEE ALSO 🌈

the kernel file ./fs/fs-writeback.c, plus literally all of these besties:

• inode_io_list_move_locked(9)
• wb_wait_for_completion(9)
• inode_cgwb_move_to_attached(9)
• locked_inode_to_wb_and_lock_list(9)
• inode_to_wb_and_lock_list(9)
• inode_switch_wbs(9)
• cleanup_offline_cgwb(9)
• wbc_attach_and_unlock_inode(9)
• wbc_attach_fdatawrite_inode(9)
• wbc_detach_inode(9)
• wbc_account_cgroup_owner(9)
• wb_split_bdi_pages(9)
• bdi_split_work_to_wbs(9)
• cgroup_writeback_by_id(9)
• cgroup_writeback_umount(9)
• wb_start_background_writeback(9)
• filemap_dontcache_kick_writeback(9)
• __mark_inode_dirty(9)
• writeback_inodes_sb(9)
• try_to_writeback_inodes_sb(9)
• sync_inodes_sb(9)
• write_inode_now(9)
• sync_inode_metadata(9)

go read them, iykyk 📚💜

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and that's the page, bestie 🎀 sign-off time: this one comes from the ./fs corner of the world, dated October 2026 — mwah, slay, go write some inodes 💖✨🔥