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 D9CE91D53C for ; Mon, 24 Jun 2024 15:54:44 +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=1719244484; cv=none; b=bE3ZeBRJrQcdQi0Tlkhq1wfqzPuWXRWSUqHIu/5obWAZ8qa3bFsUOZ4yZjX3qXTJUjHYjT6rDOeaTMHT9v92uBDLcQcbM0z6nDE3zJjTMQY3+XG06fT+GQ9vnYW+/PwBW97GDqVHSMt5eJCjpYGCdVF1FTxAKCFHNGnfeGkFCOM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719244484; c=relaxed/simple; bh=q/zTDt3G67VWad5wSqY0m3bEK5d2Ps7RRUXb6YhnHAs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cQYw0GVLp4ecTo/iaAc4t1VrTPwWuo2rqlXpp+bK5arMmdiYgLZECvxVHrN4Fa5ohGfqrh9vJx2mgPQxX7V2ZLkCfTy3O2CzihQn915mxmd2n8eNEWLiwPJRb1mrb3Y5+HuoV71tKB3kEcpz7qG4gE34q++n/aX4C/M3oCLf97w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SV+Xc8U8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SV+Xc8U8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59E85C2BBFC; Mon, 24 Jun 2024 15:54:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719244484; bh=q/zTDt3G67VWad5wSqY0m3bEK5d2Ps7RRUXb6YhnHAs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SV+Xc8U8arL5yHECVC4WQa0rajcxmzvn0M9aMDVM51JJPg+2G9INoj3G7JBYXfdGi TmfO+i1CzR7JwwF5C2geBoUmGHAs6L2nuRiZFd2r5Z6LQxNJ0avam8FhrpsP10iqnt a4303Q+lfsTRAFbMD6sgYELPoY28wVso+fauJPRqD/i6E5CIfOWrcglvFVrC95x1dh Ssvf9Xto1Jz3iM9SdNBePeXXRjAeq+n8o4Lh0Tifv+JDps3pNIBBU8dEVyylTsUbeA gdTD7umljJQd6A64A4g0lWmyvsDyyf+LMTWSKo6Qg8DrBQ/XumT6J+LnJGNtQV4iee kmp1Fgm+vfIyg== Date: Mon, 24 Jun 2024 08:54:43 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Chandan Babu R , Dave Chinner , linux-xfs@vger.kernel.org Subject: Re: [PATCH 10/10] xfs: reclaim speculative preallocations for append only files Message-ID: <20240624155443.GN3058325@frogsfrogsfrogs> References: <20240623053532.857496-1-hch@lst.de> <20240623053532.857496-11-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240623053532.857496-11-hch@lst.de> On Sun, Jun 23, 2024 at 07:34:55AM +0200, Christoph Hellwig wrote: > The XFS XFS_DIFLAG_APPEND maps to the VFS S_APPEND flag, which forbids > writes that don't append at the current EOF. > > But the commit originally adding XFS_DIFLAG_APPEND support (commit > a23321e766d in xfs xfs-import repository) also checked it to skip > releasing speculative preallocations, which doesn't make any sense. > > Another commit (dd9f438e3290 in the xfs-import repository) late extended later > that flag to also report these speculation preallocations which should > not exist in getbmap. > > Remove these checks as nothing XFS_DIFLAG_APPEND implies that > preallocations beyond EOF should exist, but explicitly check for > XFS_DIFLAG_APPEND in xfs_file_release to bypass the algorithm that > discard preallocations on the first close as append only file aren't files > expected to be written to only once. > > Signed-off-by: Christoph Hellwig > --- > fs/xfs/xfs_bmap_util.c | 12 +++++------- > fs/xfs/xfs_file.c | 4 ++++ > fs/xfs/xfs_icache.c | 2 +- > 3 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index 52863b784b023f..aa924d7cd32abd 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -331,8 +331,7 @@ xfs_getbmap( > } > > if (xfs_get_extsz_hint(ip) || > - (ip->i_diflags & > - (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))) > + (ip->i_diflags & XFS_DIFLAG_PREALLOC)) The last time you tried to remove XFS_DIFLAG_APPEND from this test, I noticed that there's some fstest that "fails" because the bmap output for an append-only file now stops at isize instead of maxbytes. Do you see this same regression? > max_len = mp->m_super->s_maxbytes; > else > max_len = XFS_ISIZE(ip); > @@ -524,12 +523,11 @@ xfs_can_free_eofblocks( > return false; > > /* > - * Only free real extents for inodes with persistent preallocations or > - * the append-only flag. > + * Do not free real extents in preallocated files unless the file has > + * delalloc blocks and we are forced to remove them. > */ > - if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) > - if (ip->i_delayed_blks == 0) > - return false; > + if ((ip->i_diflags & XFS_DIFLAG_PREALLOC) && !ip->i_delayed_blks) > + return false; > > /* > * Do not try to free post-EOF blocks if EOF is beyond the end of the > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 1903fa5568a37d..b05822a70ea680 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -1231,6 +1231,9 @@ xfs_file_release( > * one file after another without going back to it while keeping the > * preallocation for files that have recurring open/write/close cycles. > * > + * This heuristic is skipped for inodes with the append-only flag as > + * that flags is rather pointless for inodes written oly once. flag only --D > + * > * There is no point in freeing blocks here for open but unlinked files > * as they will be taken care of by the inactivation path soon. > * > @@ -1245,6 +1248,7 @@ xfs_file_release( > */ > if (inode->i_nlink && > (file->f_mode & FMODE_WRITE) && > + !(ip->i_diflags & XFS_DIFLAG_APPEND) && > !xfs_iflags_test(ip, XFS_EOFBLOCKS_RELEASED) && > xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) { > if (xfs_can_free_eofblocks(ip)) { > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c > index 9967334ea99f1a..0f07ec842b7023 100644 > --- a/fs/xfs/xfs_icache.c > +++ b/fs/xfs/xfs_icache.c > @@ -1158,7 +1158,7 @@ xfs_inode_free_eofblocks( > if (xfs_can_free_eofblocks(ip)) > return xfs_free_eofblocks(ip); > > - /* inode could be preallocated or append-only */ > + /* inode could be preallocated */ > trace_xfs_inode_free_eofblocks_invalid(ip); > xfs_inode_clear_eofblocks_tag(ip); > return 0; > -- > 2.43.0 > >