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 3FEFF16849B; Fri, 21 Jun 2024 20:38:06 +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=1719002287; cv=none; b=DeGx1YHvMqZY3Qz5wzWszzHifHWgcyfX52UzLcadLqBAFHjYEmWeNCnWugCNJNrULUVH8sLXbXQloq4JNuXVLDwyM6qXdWeTVl0pSgs3y6/j2gznzvcC8T70pr4CWe1Y2T/SKKJ5WTcEU6mstzTAVrmYZmiTnSE+0HQD2ydy0Nk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719002287; c=relaxed/simple; bh=4NZsF7nKIUwjaD/dldJqTXyP3vrorwabNNaT8yPSQ/E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PDELbWkYabSPWU1KnqVQIssjJvBNJZKzVvZCS6cFy6d1V+4Z1IBn0BdkHl5q5rN/slaA1ReMjnyjrn999o+vIMYIKdDaZno138ECsG9Du1SM77lWefzruhsz72FrdWFeCw6X/iluLCcL59XN/nmohn6FFvoB7oN3Iw0m6OlE2xE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RFjC5+pF; 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="RFjC5+pF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C116CC2BBFC; Fri, 21 Jun 2024 20:38:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719002286; bh=4NZsF7nKIUwjaD/dldJqTXyP3vrorwabNNaT8yPSQ/E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RFjC5+pFFHdzlmU9o0j0kFyLYWdQQw1CBO7m8mW8AFE0+AYe1EdtCwzkcuOsuWEH5 H2+ZEyOvJgsjSSm4EJWWX/9gGsRrpbsJSCDSRL6bkWMkYV5ZUi7khZMlCe+rA/NkUY D3uPmRdGFbKmNYSoPDOcI/iE8lNnRlmLUAi+UX2gD2dV+BuYoZoekpna8xVpsgkCyJ SxOLxGddKr9wyhu5+Ni8/czwIPfWGvoJNaCfE+PD6ylEhzECixfaQidHCcMSBim8DN sjDtp0CGMnXqTJEhBrNgUj9rCDOdjdcyvOV9CAnS6RK6tBLiPJo54IDosaBIeJZLOb Y69V7Ulq6atUQ== Date: Fri, 21 Jun 2024 13:38:06 -0700 From: "Darrick J. Wong" To: John Garry Cc: chandan.babu@oracle.com, dchinner@redhat.com, hch@lst.de, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, catherine.hoang@oracle.com, martin.petersen@oracle.com Subject: Re: [PATCH 06/13] xfs: align args->minlen for forced allocation alignment Message-ID: <20240621203806.GW3058325@frogsfrogsfrogs> References: <20240621100540.2976618-1-john.g.garry@oracle.com> <20240621100540.2976618-7-john.g.garry@oracle.com> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20240621100540.2976618-7-john.g.garry@oracle.com> On Fri, Jun 21, 2024 at 10:05:33AM +0000, John Garry wrote: > From: Dave Chinner > > If args->minlen is not aligned to the constraints of forced > alignment, we may do minlen allocations that are not aligned when we > approach ENOSPC. Avoid this by always aligning args->minlen > appropriately. If alignment of minlen results in a value smaller > than the alignment constraint, fail the allocation immediately. > > Signed-off-by: Dave Chinner > Signed-off-by: John Garry Looks good! Reviewed-by: Darrick J. Wong --D > --- > fs/xfs/libxfs/xfs_bmap.c | 45 +++++++++++++++++++++++++++------------- > 1 file changed, 31 insertions(+), 14 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > index 9131ba8113a6..c9cf138e13c4 100644 > --- a/fs/xfs/libxfs/xfs_bmap.c > +++ b/fs/xfs/libxfs/xfs_bmap.c > @@ -3278,33 +3278,48 @@ xfs_bmap_longest_free_extent( > return 0; > } > > -static xfs_extlen_t > +static int > xfs_bmap_select_minlen( > struct xfs_bmalloca *ap, > struct xfs_alloc_arg *args, > xfs_extlen_t blen) > { > - > /* Adjust best length for extent start alignment. */ > if (blen > args->alignment) > blen -= args->alignment; > > /* > * Since we used XFS_ALLOC_FLAG_TRYLOCK in _longest_free_extent(), it is > - * possible that there is enough contiguous free space for this request. > + * possible that there is enough contiguous free space for this request > + * even if best length is less that the minimum length we need. > + * > + * If the best length won't satisfy the maximum length we requested, > + * then use it as the minimum length so we get as large an allocation > + * as possible. > */ > if (blen < ap->minlen) > - return ap->minlen; > + blen = ap->minlen; > + else if (blen > args->maxlen) > + blen = args->maxlen; > > /* > - * If the best seen length is less than the request length, > - * use the best as the minimum, otherwise we've got the maxlen we > - * were asked for. > + * If we have alignment constraints, round the minlen down to match the > + * constraint so that alignment will be attempted. This may reduce the > + * allocation to smaller than was requested, so clamp the minimum to > + * ap->minlen to allow unaligned allocation to succeed. If we are forced > + * to align the allocation, return ENOSPC at this point because we don't > + * have enough contiguous free space to guarantee aligned allocation. > */ > - if (blen < args->maxlen) > - return blen; > - return args->maxlen; > - > + if (args->alignment > 1) { > + blen = rounddown(blen, args->alignment); > + if (blen < ap->minlen) { > + if (args->datatype & XFS_ALLOC_FORCEALIGN) > + return -ENOSPC; > + blen = ap->minlen; > + } > + } > + args->minlen = blen; > + return 0; > } > > static int > @@ -3340,8 +3355,7 @@ xfs_bmap_btalloc_select_lengths( > if (pag) > xfs_perag_rele(pag); > > - args->minlen = xfs_bmap_select_minlen(ap, args, blen); > - return error; > + return xfs_bmap_select_minlen(ap, args, blen); > } > > /* Update all inode and quota accounting for the allocation we just did. */ > @@ -3661,7 +3675,10 @@ xfs_bmap_btalloc_filestreams( > goto out_low_space; > } > > - args->minlen = xfs_bmap_select_minlen(ap, args, blen); > + error = xfs_bmap_select_minlen(ap, args, blen); > + if (error) > + goto out_low_space; > + > if (ap->aeof && ap->offset) > error = xfs_bmap_btalloc_at_eof(ap, args); > > -- > 2.31.1 > >