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 9878AD52F for ; Wed, 1 May 2024 21:25:20 +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=1714598720; cv=none; b=CSz5oaUx0F3XVKb3KYoLbiylvOSIIPVeNqIBFmmGAwcPuggaQQdIi9V7SAjyv/UN6psed9fclrG1OSQgJUbQD0rTY9IprTmIpV03CQ0cyiYkm4bDUVJ21ZFUCLVmqggM55FlLMWq6RNkJIyU2T2WnrEYfwbvjix1IKKgeLHStJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714598720; c=relaxed/simple; bh=6S3CGg5/9/TicSDcr/lXOyi+fgEuJNI2Hql9pc0EnGE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UZfyQ6h8wfhbVMvFZf4viJgea9pNOy0+LnRMgIjNo56c8EPnOXPoy+/7ZsuC0HYbZhfeVlGUOVwPd0iCGGvcgoZ4K6NZnvcOlssQu05DvGyYqapSoB+wYe2DFvVAppp14hOSTxU9NWNqnl8mgcrpaxlvYZ/DagimuaQHB6SUlPg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NIVlWmMo; 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="NIVlWmMo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04B01C072AA; Wed, 1 May 2024 21:25:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714598720; bh=6S3CGg5/9/TicSDcr/lXOyi+fgEuJNI2Hql9pc0EnGE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NIVlWmMojA6E0jOK/R+kVt+LDPCLOYeZknHG43knQCol6EXzPCad4PWV67MgzStU2 gGHZtTHxhxOcsLmjhgUyEsaEwrqH9vU8T1/1cdpUHltLWz5ISAQfarVjYxKur8K1MM +/9b3lQBKz7Iv7H9lz+MKaXOzMZzYIcy8uwcMbTGfczo8qcjhTTnhxgW9le2tgNiHb eUeDLfCIxIbsiTayunuZHtmLHgXsEAWUCEtrjbFbLeaIDF6R0DpsZ18dZvsYxQpGIV kWq5oXjdQO73hhuz1eieLjxjrjA62z4LXOWgYcs300J1pRRsZ6gtrWBtCW0/+1TJxC 1Y0uqc/5tr8NQ== Date: Wed, 1 May 2024 14:25:19 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Chandan Babu R , linux-xfs@vger.kernel.org Subject: Re: [PATCH 10/16] xfs: optimize removing the last 8-byte inode from a shortform directory Message-ID: <20240501212519.GY360919@frogsfrogsfrogs> References: <20240430124926.1775355-1-hch@lst.de> <20240430124926.1775355-11-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: <20240430124926.1775355-11-hch@lst.de> On Tue, Apr 30, 2024 at 02:49:20PM +0200, Christoph Hellwig wrote: > When removing the last 8-byte inode, xfs_dir2_sf_removename calls > xfs_dir2_sf_toino4 after removing the entry. This is rather inefficient > as it causes two buffer realloacations. Instead of that pass a bool > argument to xfs_dir2_sf_toino4 so that it can remove the entry pointed > to by args as part of the conversion and use that to shortcut the > process. > > Signed-off-by: Christoph Hellwig > --- > fs/xfs/libxfs/xfs_dir2_sf.c | 41 ++++++++++++++++++++++++++++--------- > 1 file changed, 31 insertions(+), 10 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_dir2_sf.c b/fs/xfs/libxfs/xfs_dir2_sf.c > index 3b6d6dda92f29f..21e04594606b89 100644 > --- a/fs/xfs/libxfs/xfs_dir2_sf.c > +++ b/fs/xfs/libxfs/xfs_dir2_sf.c > @@ -34,7 +34,7 @@ static void xfs_dir2_sf_check(xfs_da_args_t *args); > #define xfs_dir2_sf_check(args) > #endif /* DEBUG */ > > -static void xfs_dir2_sf_toino4(xfs_da_args_t *args); > +static void xfs_dir2_sf_toino4(struct xfs_da_args *args, bool remove); > static void xfs_dir2_sf_toino8(xfs_da_args_t *args); > > int > @@ -935,6 +935,15 @@ xfs_dir2_sf_removename( > ASSERT(dp->i_df.if_bytes == oldsize); > ASSERT(oldsize >= xfs_dir2_sf_hdr_size(sfp->i8count)); > > + /* > + * If this is the last 8-byte, directly convert to the 4-byte format > + * and just skip the removed entry when building the new fork. > + */ > + if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && sfp->i8count == 1) { > + xfs_dir2_sf_toino4(args, true); > + return 0; > + } > + > /* > * Loop over the old directory entries. > * Find the one we're deleting. > @@ -980,10 +989,8 @@ xfs_dir2_sf_removename( > * Are we changing inode number size? > */ > if (args->inumber > XFS_DIR2_MAX_SHORT_INUM) { > - if (sfp->i8count == 1) > - xfs_dir2_sf_toino4(args); > - else > - sfp->i8count--; > + ASSERT(sfp->i8count > 1); > + sfp->i8count--; > } > xfs_dir2_sf_check(args); > xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA); > @@ -1087,7 +1094,7 @@ xfs_dir2_sf_replace( > if (i == sfp->count) { > ASSERT(args->op_flags & XFS_DA_OP_OKNOENT); > if (i8elevated) > - xfs_dir2_sf_toino4(args); > + xfs_dir2_sf_toino4(args, false); > return -ENOENT; > } > } > @@ -1100,7 +1107,7 @@ xfs_dir2_sf_replace( > * And the old count was one, so need to convert to small. > */ > if (sfp->i8count == 1) > - xfs_dir2_sf_toino4(args); > + xfs_dir2_sf_toino4(args, false); > else > sfp->i8count--; > } > @@ -1128,7 +1135,8 @@ xfs_dir2_sf_replace( > */ > static void > xfs_dir2_sf_toino4( > - xfs_da_args_t *args) /* operation arguments */ > + struct xfs_da_args *args, > + bool remove) > { > struct xfs_inode *dp = args->dp; > struct xfs_mount *mp = dp->i_mount; > @@ -1148,6 +1156,8 @@ xfs_dir2_sf_toino4( > * Compute the new inode size. > */ > newsize = oldsize - (oldsfp->count + 1) * XFS_INO64_DIFF; > + if (remove) > + newsize -= xfs_dir2_sf_entsize(mp, oldsfp, args->namelen); > > dp->i_df.if_data = sfp = kmalloc(newsize, GFP_KERNEL | __GFP_NOFAIL); > dp->i_df.if_bytes = newsize; > @@ -1166,11 +1176,22 @@ xfs_dir2_sf_toino4( > i < sfp->count; > i++, sfep = xfs_dir2_sf_nextentry(mp, sfp, sfep), > oldsfep = xfs_dir2_sf_nextentry(mp, oldsfp, oldsfep)) { > + xfs_ino_t ino = xfs_dir2_sf_get_ino(mp, oldsfp, oldsfep); > + > + /* > + * Just skip over the entry that is removed if there is one. > + */ > + if (remove && args->inumber == ino) { > + oldsfep = xfs_dir2_sf_nextentry(mp, oldsfp, oldsfep); > + sfp->count--; > + if (++i == sfp->count) > + break; > + } What happens if a shortform directory contains two entries to the same file? I think @remove really means that the caller has verified that the sf directory only contains one link @args->inumber? If that's so, then the comment for this function should say that. --D > + > sfep->namelen = oldsfep->namelen; > memcpy(sfep->offset, oldsfep->offset, sizeof(sfep->offset)); > memcpy(sfep->name, oldsfep->name, sfep->namelen); > - xfs_dir2_sf_put_ino(mp, sfp, sfep, > - xfs_dir2_sf_get_ino(mp, oldsfp, oldsfep)); > + xfs_dir2_sf_put_ino(mp, sfp, sfep, ino); > xfs_dir2_sf_put_ftype(mp, sfep, > xfs_dir2_sf_get_ftype(mp, oldsfep)); > } > -- > 2.39.2 > >