filemap_flush_range(9)

👑 filemap_flush_range(9) — Kernel API Manual, bestie edition

okay so picture this: it's a kernel API manual page, it's called filemap_flush_range, and it is literally the "hey babe, go write that stuff out" of mm/filemap.c. no cap. let's get into it 🫶

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✨ NAME ✨

filemap_flush_range — start writeback on a range 💅

yes that's it that's the whole name section, she's petite but she SERVES

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🌸 SYNOPSIS 🌸

int filemap_flush_range (struct address_space *mapping , loff_t start ,
loff_t end );

look at her. three args. returns an int. iconic behavior honestly 🎀

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🦋 ARGUMENTS 🦋

• mapping — the target address_space. this is the vibes container you're operating on, the main character of the whole operation 🌈
• start — the index to start writeback on. your starting point, your "we begin here" moment ✨
• end — the last (inclusive!!) index for writeback. yes bestie, inclusive, so end gets an invite to the party too 💖

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💜 DESCRIPTION 💜

so what does she actually do? she's a non-integrity writeback helper — say that again, non-integrity, meaning she is NOT out here doing the whole integrity dance, okay? she's just the casual one 🧚

her one job: start writing back folios for the indicated range. that's the whole gig. she doesn't verify, she doesn't wait around, she doesn't text back — she just kicks off the writeback for the folios in that range you gave her 🔥

lowkey a queen of delegation, ngl.

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⭐ RETURN ⭐

• 0 on success 🎉
• a negative error code otherwise 😭

so like, if it's 0, we're slaying. if it's negative, something went sideways and she's telling you about it via the return value. read it. respect it. 🙈

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🌈 SEE ALSO 🌈

the full squad, in order, no skipping, no cutting corners, we love a complete rotation:

• Kernel file ./mm/filemap.c — the source file where all this magic lives 💫
• filemap_remove_folio(9)
• filemap_fdatawrite_range(9)
• filemap_flush(9)
• filemap_range_has_page(9)
• filemap_fdatawait_range(9)
• filemap_fdatawait_range_keep_errors(9)
• file_fdatawait_range(9)
• filemap_fdatawait_keep_errors(9)
• filemap_write_and_wait_range(9)
• file_check_and_advance_wb_err(9)
• file_write_and_wait_range(9)
• replace_page_cache_folio(9)
• softleaf_entry_wait_on_locked(9)
• folio_put_wait_locked(9)
• folio_unlock(9)
• folio_end_read(9)
• folio_end_private_2(9)
• folio_wait_private_2(9)
• folio_wait_private_2_killable(9)
• folio_end_writeback_no_dropbehind(9)
• folio_end_writeback(9)
• __folio_lock(9)
• page_cache_next_miss(9)
• page_cache_prev_miss(9)
• __filemap_get_folio_mpol(9)
• find_get_entries(9)
• find_lock_entries(9)
• filemap_get_folios(9)
• filemap_get_folios_contig(9)
• filemap_get_folios_tag(9)
• filemap_get_folios_dirty(9)
• filemap_read(9)
• generic_file_read_iter(9)
• filemap_splice_read(9)
• mapping_seek_hole_data(9)
• filemap_fault(9)
• read_cache_folio(9)
• mapping_read_folio_gfp(9)
• read_cache_page_gfp(9)
• __generic_file_write_iter(9)
• generic_file_write_iter(9)
• filemap_release_folio(9)
• filemap_invalidate_inode(9)
• filemap_cachestat(9)

like, that's the whole friend group right there. go read them. iykyk 💀

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and that's the page, bestie!! 💖 this one came from the ./mm source, dated October 2026, and it signs off as filemap_flush_range(9) — so if you cite her, cite her right. mwah. 🍓👑