From patchwork Tue Oct 8 08:59:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13826023 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 C417B18C922; Tue, 8 Oct 2024 08:59:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728377992; cv=none; b=qME+8kKanwEJ9nV2aRZgJzGwxOCq3JAia23Dh0WcvqIr8MJgRtKrN/UegVivzQZ/IPzQ6//lUtrckMYVFNGsa+b4hqfFmgaSWKp9SX8Q6c8tKZBJ72i5RFfsGmczrrsQ29iZlqwIqAkvAPnt0R/02dZGBgV9ViXDUATyvbHxhAI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728377992; c=relaxed/simple; bh=djuMtwPMA51ml07WieONMs5DWN1/mySMKle3yqHnmhA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d7dJOFgrvWPuk+zYaq4EzCkJSzGJXWCdVrdRBziwqn+2lMjdcT7kr52wymsgcpoIr2G+VzFL3Mf5QzDZG8a0kJq86c9NJgQvrcAUWimo84+E44UAh+x3dgDrb0CTEl2CYcu28PoovXSzXIVfEcPlJvWP5kFgCNQKW9+8oO0ikoo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=4gRhboHE; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="4gRhboHE" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=kDPiv7AZVrWNmGKxIXeYJtT3OdYEgQsKaa7LjBwdvvo=; b=4gRhboHEBAbNqYnXBpd5wKoPiD cQzLTQ3w4CkCoZArGjMxeV2pOY6FQl+jhenLYjwMfq/2a65UEx12fBq/YuP8aE72O1dUq4xpvqMAB 6t5511slXGagYfnszVVkIwwBu0tKHJmkXxO6P28NRTwHfY3iRjiAofa4kQc/TVJ/95HwRJtlk3KvB 6xC0AjJqztLh3MOg0TWvbZu6wQInJP7dTosjFFJITZ191GpqIYG0TViGxOjhPckkqvPkD0kQ4nNHB XQzm+vRUC9A7aCxV5HjGMpWhhCsSO2RqgfTQLneBebEGYR9IYoH3lEIMkfbv7DpWsh6tj8hdu7lwe 6BRi71Tw==; Received: from 2a02-8389-2341-5b80-a172-fba5-598b-c40c.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:a172:fba5:598b:c40c] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1sy64M-00000005Bc4-0RR6; Tue, 08 Oct 2024 08:59:50 +0000 From: Christoph Hellwig To: Carlos Maiolino , Christian Brauner , "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 03/10] iomap: move locking out of iomap_write_delalloc_release Date: Tue, 8 Oct 2024 10:59:14 +0200 Message-ID: <20241008085939.266014-4-hch@lst.de> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241008085939.266014-1-hch@lst.de> References: <20241008085939.266014-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html XFS (which currently is the only user of iomap_write_delalloc_release) already holds invalidate_lock for most zeroing operations. To be able to avoid a deadlock it needs to stop taking the lock, but doing so in iomap would leak XFS locking details into iomap. To avoid this require the caller to hold invalidate_lock when calling iomap_write_delalloc_release instead of taking it there. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 17 ++++++++--------- fs/xfs/xfs_iomap.c | 2 ++ 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index b4f742f3104120..aa587b2142e214 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1211,12 +1211,13 @@ void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte, loff_t scan_end_byte = min(i_size_read(inode), end_byte); /* - * Lock the mapping to avoid races with page faults re-instantiating - * folios and dirtying them via ->page_mkwrite whilst we walk the - * cache and perform delalloc extent removal. Failing to do this can - * leave dirty pages with no space reservation in the cache. + * The caller must hold invalidate_lock to avoid races with page faults + * re-instantiating folios and dirtying them via ->page_mkwrite whilst + * we walk the cache and perform delalloc extent removal. Failing to do + * this can leave dirty pages with no space reservation in the cache. */ - filemap_invalidate_lock(inode->i_mapping); + lockdep_assert_held_write(&inode->i_mapping->invalidate_lock); + while (start_byte < scan_end_byte) { loff_t data_end; @@ -1233,7 +1234,7 @@ void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte, if (start_byte == -ENXIO || start_byte == scan_end_byte) break; if (WARN_ON_ONCE(start_byte < 0)) - goto out_unlock; + return; WARN_ON_ONCE(start_byte < punch_start_byte); WARN_ON_ONCE(start_byte > scan_end_byte); @@ -1244,7 +1245,7 @@ void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte, data_end = mapping_seek_hole_data(inode->i_mapping, start_byte, scan_end_byte, SEEK_HOLE); if (WARN_ON_ONCE(data_end < 0)) - goto out_unlock; + return; /* * If we race with post-direct I/O invalidation of the page cache, @@ -1266,8 +1267,6 @@ void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte, if (punch_start_byte < end_byte) punch(inode, punch_start_byte, end_byte - punch_start_byte, iomap); -out_unlock: - filemap_invalidate_unlock(inode->i_mapping); } EXPORT_SYMBOL_GPL(iomap_write_delalloc_release); diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 30f2530b6d5461..01324da63fcfc7 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1239,8 +1239,10 @@ xfs_buffered_write_iomap_end( if (start_byte >= end_byte) return 0; + filemap_invalidate_lock(inode->i_mapping); iomap_write_delalloc_release(inode, start_byte, end_byte, flags, iomap, xfs_buffered_write_delalloc_punch); + filemap_invalidate_unlock(inode->i_mapping); return 0; }