From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794341980; b=hsoMqxy0kgGvNcgEoC47tWslW5Ps5WwoDliaY8qVxyim6iQlPIbPsklkbCMX27IfWecO b6Hhg/XK9V4GWkHGTv3tFtB7hVbCpZ79kZu0xpKruKb4KmPN8lC6HMtMtRTrpHhw1x/3u pwIs5M63hF9Us7Jld6eGtjWOwRef79YjaUMByiIm/5ceAFLp/9kxy4CUrkNFNt25Qp7uS V9kUhBxSVSgeeXxBugwQXtwIKgzGJ9JfrCBEua3xUv2szTv7tOFSpeaMH/MUZORVmX7qy Eoyt5MQL7BaFdfiDKEohoUEL9QvCfgmGkIfyLiotwmMW4rpMrJgYdmuapwyaYYQRR+w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794341980; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=n6yyIq+xXmWvuPfaTqKkrFwS4og2xCZua+WGsMHYlBA=; b=yX1lPgks7wpTMqaipffLxMAjg0sd42WAGjQvjBl1IUpqNpSZFhj2Tje0STt3FZuc6oe7 ltzeDeBzq1t+/nMjTyDUEubTonc2yURvCVp7SPaFyOykjASzbX3DZYvWS89oRkXPHyaMP Wp2Ca2MYbp6Kp80L4+WpOAUhFA7qje/kVk5akrxYRjWqozvP67bzlmCzh7bOFRDKkWaXm H86tZc/Ouqe08xHRoUrzuOtErrhRyfceo4YYuidUwQA8nF0cXobOjyR8ISr4lSNDq05yV 6VLHbLwtA1W86Jv/Nu5GNfTB7Ff7HEShdDBZnpnt5mUDgpSnrDCgeXI7cIhSjmYY25A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="Ee/ZjfBX"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5AF03606A31C for ; Tue, 10 Nov 2026 20:19:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Ee/ZjfBX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 587CA1F0089F; Tue, 10 Nov 2026 20:19:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794341979; bh=n6yyIq+xXmWvuPfaTqKkrFwS4og2xCZua+WGsMHYlBA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Ee/ZjfBXVMpSpQKBtZ4n2udjrDaEgbyqINq4EiwyR4SOxnZgGMAnhKEHWdcx3CJz3 F8RYeQPUAP1UJw8ojOEhGgz8mNVQlKkBgCTvvEGClUosiOwOCoE2KILNerPvPiI4Rs e0VCc32gHQZSA4mUK46V34VTk05AcE1ppdkrvtvb9MSZh3e1fbXKvAZIXPssxBmRXS 63UoCdrInHHL2dqnFDbyoPOz6HWb+D2pKNJrKNjpdVtLXcTAoT7ojOtNuxTXG+1jun X6Rc+PVcx0eJMqRK8ZRmUfi3QBiK92s/z51Un8KYc+Rcx5mIulAl5Z+VZdaWHMg8Q4 VmZER3G3DZWiw== From: Sasha Levin To: stable@vger.kernel.org Cc: Jiaming Zhang , Ryusuke Konishi , Viacheslav Dubeyko , Sasha Levin Subject: [PATCH 5.10.y] nilfs2: force clear dirty state when restoring from the shadow map Date: Tue, 10 Nov 2026 15:19:38 -0500 Message-ID: <20261110201922.3767932-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107061606-failed-5.10-cb6702e63e0a@kernel.org> References: <20261107061606-failed-5.10-cb6702e63e0a@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jiaming Zhang [ Upstream commit cb6702e63e0a16afd83875294e5ce53becdd1b1f ] When garbage collection fails, nilfs2 rolls the DAT metadata file's page cache back to a shadow copy taken before GC started. nilfs_clear_dirty_pages() drops the dirty state of the folios in the DAT cache, then nilfs_copy_back_pages() overwrites them with the saved contents and warns if one is still dirty: /* overwrite existing folio in the destination cache */ WARN_ON(folio_test_dirty(dfolio)); nilfs_clear_dirty_pages() used to clear the dirty state unconditionally, which is safe here because the rollback runs with the log writer stopped, so nothing else can dirty the cache while it runs. The same helper is also used when writeback finds dirty folios after the filesystem has degraded to read-only, where it does run concurrently with the log writer, so commit ca76bb226bf4 ("nilfs2: do not force clear folio if buffer is referenced") made nilfs_clear_folio_dirty() skip a folio if any of its buffer heads is busy. The rollback caller shares that helper, so its clearing step can now return with a folio still dirty. A DAT folio can hold a busy buffer head without anyone modifying the folio: nilfs_mdt_read_block() submits read-ahead for the blocks following the one it was asked for and waits only for the first, so the read-ahead buffers are still locked when it returns. With a block size smaller than the page size, a locked read-ahead buffer can share a folio with a block that GC dirtied and keep the whole folio dirty past the clearing step. Add a force flag to nilfs_clear_dirty_pages() and nilfs_clear_folio_dirty() that skips the busy buffer check, and set it in the two calls from nilfs_mdt_restore_from_shadow_map(). The read-only fallback callers keep passing false, so that commit still protects them and the WARN_ON() is left alone. Fixes: ca76bb226bf4 ("nilfs2: do not force clear folio if buffer is referenced") Closes: https://lore.kernel.org/lkml/CANypQFZSYrtcshnUzOPiqatyLd-M8_OReOewQoAi_V5yY0dTtg@mail.gmail.com/ Cc: stable@vger.kernel.org Suggested-by: Ryusuke Konishi Assisted-by: Claude Code:claude-opus-5 Signed-off-by: Jiaming Zhang Acked-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko [ sashal: Adapted folio-based dirty-state handling to the page-based API, including the additional nilfs_writepage() caller. ] Signed-off-by: Sasha Levin --- fs/nilfs2/inode.c | 4 ++-- fs/nilfs2/mdt.c | 6 +++--- fs/nilfs2/page.c | 50 +++++++++++++++++++++++++++-------------------- fs/nilfs2/page.h | 4 ++-- 4 files changed, 36 insertions(+), 28 deletions(-) diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 581ab03442015..a945b008a02d3 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -162,7 +162,7 @@ static int nilfs_writepages(struct address_space *mapping, int err = 0; if (sb_rdonly(inode->i_sb)) { - nilfs_clear_dirty_pages(mapping); + nilfs_clear_dirty_pages(mapping, false); return -EROFS; } @@ -185,7 +185,7 @@ static int nilfs_writepage(struct page *page, struct writeback_control *wbc) * have dirty pages that try to be flushed in background. * So, here we simply discard this dirty page. */ - nilfs_clear_dirty_page(page); + nilfs_clear_dirty_page(page, false); unlock_page(page); return -EROFS; } diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c index 1a907acc701d7..c1f9649164897 100644 --- a/fs/nilfs2/mdt.c +++ b/fs/nilfs2/mdt.c @@ -410,7 +410,7 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc) * have dirty pages that try to be flushed in background. * So, here we simply discard this dirty page. */ - nilfs_clear_dirty_page(page); + nilfs_clear_dirty_page(page, false); unlock_page(page); return -EROFS; } @@ -631,10 +631,10 @@ void nilfs_mdt_restore_from_shadow_map(struct inode *inode) if (mi->mi_palloc_cache) nilfs_palloc_clear_cache(inode); - nilfs_clear_dirty_pages(inode->i_mapping); + nilfs_clear_dirty_pages(inode->i_mapping, true); nilfs_copy_back_pages(inode->i_mapping, shadow->inode->i_mapping); - nilfs_clear_dirty_pages(ii->i_assoc_inode->i_mapping); + nilfs_clear_dirty_pages(ii->i_assoc_inode->i_mapping, true); nilfs_copy_back_pages(ii->i_assoc_inode->i_mapping, NILFS_I(shadow->inode)->i_assoc_inode->i_mapping); diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index ce5947cf4bd51..55dfd243cda0e 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -354,8 +354,9 @@ void nilfs_copy_back_pages(struct address_space *dmap, /** * nilfs_clear_dirty_pages - discard dirty pages in address space * @mapping: address space with dirty pages for discarding + * @force: whether to clear the dirty state regardless of busy buffer heads */ -void nilfs_clear_dirty_pages(struct address_space *mapping) +void nilfs_clear_dirty_pages(struct address_space *mapping, bool force) { struct pagevec pvec; unsigned int i; @@ -376,7 +377,7 @@ void nilfs_clear_dirty_pages(struct address_space *mapping) * was acquired. Skip processing in that case. */ if (likely(page->mapping == mapping)) - nilfs_clear_dirty_page(page); + nilfs_clear_dirty_page(page, force); unlock_page(page); } @@ -388,13 +389,16 @@ void nilfs_clear_dirty_pages(struct address_space *mapping) /** * nilfs_clear_dirty_page - discard dirty page * @page: dirty page that will be discarded + * @force: whether to clear the states regardless of busy buffer heads * * nilfs_clear_dirty_page() clears working states including dirty state for - * the page and its buffers. If the page has buffers, clear only if it is - * confirmed that none of the buffer heads are busy (none have valid - * references and none are locked). + * the page and its buffers. If the page has buffers and force is false, + * clear only if it is confirmed that none of the buffer heads are busy (none + * have valid references and none are locked). If force is true, the states + * are cleared unconditionally, the caller should guarantee that the page is + * not being modified concurrently. */ -void nilfs_clear_dirty_page(struct page *page) +void nilfs_clear_dirty_page(struct page *page, bool force) { BUG_ON(!PageLocked(page)); @@ -405,24 +409,28 @@ void nilfs_clear_dirty_page(struct page *page) BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected) | BIT(BH_Delay)); - bool busy, invalidated = false; + + if (!force) { + bool busy, invalidated = false; recheck_buffers: - busy = false; - bh = head; - do { - if (atomic_read(&bh->b_count) | buffer_locked(bh)) { - busy = true; - break; + busy = false; + bh = head; + do { + if (atomic_read(&bh->b_count) | + buffer_locked(bh)) { + busy = true; + break; + } + } while (bh = bh->b_this_page, bh != head); + + if (busy) { + if (invalidated) + return; + invalidate_bh_lrus(); + invalidated = true; + goto recheck_buffers; } - } while (bh = bh->b_this_page, bh != head); - - if (busy) { - if (invalidated) - return; - invalidate_bh_lrus(); - invalidated = true; - goto recheck_buffers; } bh = head; diff --git a/fs/nilfs2/page.h b/fs/nilfs2/page.h index a5b9b5a457ab2..be2d089748d8c 100644 --- a/fs/nilfs2/page.h +++ b/fs/nilfs2/page.h @@ -41,8 +41,8 @@ void nilfs_page_bug(struct page *); int nilfs_copy_dirty_pages(struct address_space *, struct address_space *); void nilfs_copy_back_pages(struct address_space *, struct address_space *); -void nilfs_clear_dirty_page(struct page *page); -void nilfs_clear_dirty_pages(struct address_space *mapping); +void nilfs_clear_dirty_page(struct page *page, bool force); +void nilfs_clear_dirty_pages(struct address_space *mapping, bool force); void nilfs_mapping_init(struct address_space *mapping, struct inode *inode); unsigned int nilfs_page_count_clean_buffers(struct page *, unsigned int, unsigned int); -- 2.53.0