From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54AE53C488 for ; Wed, 21 Feb 2024 20:51:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708548686; cv=none; b=uvrvHBuo55FgLDve+/eBYGzDwXMti77oDwDcZ1yRVR411WBQkF4ff4O1r+xv3R5a45bmnSNORui9I4oapTHgDQNelhsrY8Fxau9qR7sZHiVuB25zIR4FrdgR00lYHvirZymWdh5pd2UiQ+n9T7PIfSzjHOWtJfKr03WerIJDVHY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708548686; c=relaxed/simple; bh=Al1gwrlKg70mLrYeHJJ0iaQveA/64p2ruCbIXa2dky0=; h=Date:To:From:Subject:Message-Id; b=gQpCBlCXUCI7Vnaf2rch0lOa3eGTVaxwSacWhQ4LBJ92/E8xdKMkd5shEJ2LUKzYGU+hR2XCp7T7b6dtOMTAO9EgOxlBU5uPP62ceTKYDjasr4TSULz+RSR0k73xJnX5Tb9p44sAoMtQDHZ0U4Brs6Aep/7h3CqtkyV5BLxgYCg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=eRV5iihV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="eRV5iihV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5142C433F1; Wed, 21 Feb 2024 20:51:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1708548685; bh=Al1gwrlKg70mLrYeHJJ0iaQveA/64p2ruCbIXa2dky0=; h=Date:To:From:Subject:From; b=eRV5iihVwERaGocZrfiEP11aKkVUaPPbhk2SgST55EfzTEZA3Fy6vTGorymIj8SWI l4VCDLOZstmPMPJnXuGpnW088WuHoJhjlU7FZb2EQE5CasGOLnV43j+rFxuudF+kDu EHBp0lQeQRR6j8UfzHCZhIZaEPMD6P3VCmaPEOaY= Date: Wed, 21 Feb 2024 12:51:25 -0800 To: mm-commits@vger.kernel.org,willy@infradead.org,jack@suse.cz,dhowells@redhat.com,dchinner@redhat.com,brauner@kernel.org,bfoster@redhat.com,hch@lst.de,akpm@linux-foundation.org From: Andrew Morton Subject: + writeback-only-update-writeback_index-for-range_cyclic-writeback.patch added to mm-unstable branch Message-Id: <20240221205125.B5142C433F1@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: writeback: only update ->writeback_index for range_cyclic writeback has been added to the -mm mm-unstable branch. Its filename is writeback-only-update-writeback_index-for-range_cyclic-writeback.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/writeback-only-update-writeback_index-for-range_cyclic-writeback.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Christoph Hellwig Subject: writeback: only update ->writeback_index for range_cyclic writeback Date: Thu, 15 Feb 2024 07:36:40 +0100 mapping->writeback_index is only [1] used as the starting point for range_cyclic writeback, so there is no point in updating it for other types of writeback. [1] except for btrfs_defrag_file which does really odd things with mapping->writeback_index. But btrfs doesn't use write_cache_pages at all, so this isn't relevant here. Link: https://lkml.kernel.org/r/20240215063649.2164017-6-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Reviewed-by: Jan Kara Acked-by: Dave Chinner Cc: Christian Brauner Cc: David Howells Cc: "Matthew Wilcox (Oracle)" Signed-off-by: Andrew Morton --- mm/page-writeback.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) --- a/mm/page-writeback.c~writeback-only-update-writeback_index-for-range_cyclic-writeback +++ a/mm/page-writeback.c @@ -2403,7 +2403,6 @@ int write_cache_pages(struct address_spa pgoff_t index; pgoff_t end; /* Inclusive */ pgoff_t done_index; - int range_whole = 0; xa_mark_t tag; folio_batch_init(&fbatch); @@ -2413,8 +2412,6 @@ int write_cache_pages(struct address_spa } else { index = wbc->range_start >> PAGE_SHIFT; end = wbc->range_end >> PAGE_SHIFT; - if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) - range_whole = 1; } if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) { tag_pages_for_writeback(mapping, index, end); @@ -2518,14 +2515,21 @@ continue_unlock: } /* - * If we hit the last page and there is more work to be done: wrap - * back the index back to the start of the file for the next - * time we are called. + * For range cyclic writeback we need to remember where we stopped so + * that we can continue there next time we are called. If we hit the + * last page and there is more work to be done, wrap back to the start + * of the file. + * + * For non-cyclic writeback we always start looking up at the beginning + * of the file if we are called again, which can only happen due to + * -ENOMEM from the file system. */ - if (wbc->range_cyclic && !done) - done_index = 0; - if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) - mapping->writeback_index = done_index; + if (wbc->range_cyclic) { + if (done) + mapping->writeback_index = done_index; + else + mapping->writeback_index = 0; + } return ret; } _ Patches currently in -mm which might be from hch@lst.de are writeback-dont-call-mapping_set_error-on-aop_writepage_activate.patch writeback-fix-done_index-when-hitting-the-wbc-nr_to_write.patch writeback-also-update-wbc-nr_to_write-on-writeback-failure.patch writeback-only-update-writeback_index-for-range_cyclic-writeback.patch writeback-rework-the-loop-termination-condition-in-write_cache_pages.patch writeback-add-a-writeback-iterator.patch