filemap_sample_wb_err(9)

💅 filemap_sample_wb_err — bestie, it's giving Kernel API Manual, section 9 ✨

okay so this is the manual page for filemap_sample_wb_err(9), filed under the Kernel API Manual, and it's literally all about grabbing a little sample point so you can test for writeback errors later. slay. let's get into it 🫶

🌸 NAME 🌸

filemap_sample_wb_err — sample the current errseq_t so you can test for later errors, periodt.

✨ SYNOPSIS ✨

errseq_t filemap_sample_wb_err (struct address_space *mapping );

🎀 ARGUMENTS 🎀

• mapping — the mapping that's getting sampled, bestie. that's it. that's the vibe.

🦋 DESCRIPTION 🦋

okay so real talk: writeback errors are always reported relative to a particular sample point in the past. like, that's the whole thing. no cap. and this function? it's the one providing those sample points. iconic behavior, honestly 💅

💜 SEE ALSO 💜

kernel file ./include/linux/pagemap.h, plus a whole friend group of cross-references — every single one of these, because we don't skip anyone in this house:

• filemap_set_wb_err(9)
• filemap_check_wb_err(9)
• file_sample_sb_err(9)
• mapping_set_error(9)
• mapping_set_large_folios(9)
• mapping_align_index(9)
• mapping_pmd_folio_support(9)
• folio_flush_mapping(9)
• folio_inode(9)
• folio_attach_private(9)
• folio_change_private(9)
• folio_detach_private(9)
• fgf_t(9)
• fgf_set_order(9)
• write_begin_get_folio(9)
• filemap_get_folio(9)
• filemap_lock_folio(9)
• filemap_grab_folio(9)
• find_get_page(9)
• find_lock_page(9)
• find_or_create_page(9)
• grab_cache_page_nowait(9)
• folio_next_index(9)
• folio_next_pos(9)
• folio_file_page(9)
• folio_contains(9)
• page_pgoff(9)
• folio_pos(9)
• linear_page_delta(9)
• linear_page_index(9)
• linear_anon_page_index(9)
• folio_trylock(9)
• folio_lock(9)
• lock_page(9)
• folio_lock_killable(9)
• filemap_range_needs_writeback(9)
• struct readahead_control(9)
• page_cache_sync_readahead(9)
• page_cache_async_readahead(9)
• readahead_folio(9)
• readahead_pos(9)
• readahead_length(9)
• readahead_index(9)
• readahead_count(9)
• readahead_batch_length(9)
• folio_mkwrite_check_truncate(9)
• i_blocks_per_folio(9)

and that's the page, bestie 💖 source lives in ./include/linux, dated October 2026, so go off and sample responsibly. mwah 🎀✨