From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:34233 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752900AbdJUA1S (ORCPT ); Fri, 20 Oct 2017 20:27:18 -0400 Date: Fri, 20 Oct 2017 17:27:14 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 14/15] xfs: don't rely on extent indices in xfs_bmap_insert_extents Message-ID: <20171021002714.GH4755@magnolia> References: <20171019065942.18813-1-hch@lst.de> <20171019065942.18813-15-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171019065942.18813-15-hch@lst.de> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Christoph Hellwig Cc: linux-xfs@vger.kernel.org On Thu, Oct 19, 2017 at 08:59:41AM +0200, Christoph Hellwig wrote: > Rewrite xfs_bmap_insert_extents so that we don't rely on extent indices > except for iterating over them. Not being able to iterate to the previous > extent or finding the extent that stop_fsb is in are sufficient exit > conditions, and we don't need to do any extent count games given that: > > a) we already flushed all delalloc extents past our start offset > before doing the operation > b) xfs_iext_count() includes delalloc extents anyway > > Signed-off-by: Christoph Hellwig Looks ok, Reviewed-by: Darrick J. Wong > --- > fs/xfs/libxfs/xfs_bmap.c | 47 +++++++++-------------------------------------- > 1 file changed, 9 insertions(+), 38 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > index 4c89fdacda90..9b638cc49f5c 100644 > --- a/fs/xfs/libxfs/xfs_bmap.c > +++ b/fs/xfs/libxfs/xfs_bmap.c > @@ -5726,10 +5726,8 @@ xfs_bmap_insert_extents( > struct xfs_mount *mp = ip->i_mount; > struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); > struct xfs_btree_cur *cur = NULL; > - struct xfs_bmbt_irec got, next, s; > + struct xfs_bmbt_irec got, next; > xfs_extnum_t current_ext; > - xfs_extnum_t total_extents; > - xfs_extnum_t stop_extent; > xfs_fileoff_t new_startoff; > int error = 0; > int logflags = 0; > @@ -5760,37 +5758,14 @@ xfs_bmap_insert_extents( > cur->bc_private.b.flags = 0; > } > > - /* > - * There may be delalloc extents in the data fork before the range we > - * are collapsing out, so we cannot use the count of real extents here. > - * Instead we have to calculate it from the incore fork. > - */ > - total_extents = xfs_iext_count(ifp); > - if (total_extents == 0) { > - *done = true; > - goto del_cursor; > - } > - > - /* > - * In case of first right shift, we need to initialize next_fsb > - */ > if (*next_fsb == NULLFSBLOCK) { > - current_ext = total_extents - 1; > - xfs_iext_get_extent(ifp, current_ext, &got); > - if (stop_fsb > got.br_startoff) { > + current_ext = xfs_iext_count(ifp) - 1; > + if (!xfs_iext_get_extent(ifp, current_ext, &got) || > + stop_fsb > got.br_startoff) { > *done = true; > goto del_cursor; > } > - *next_fsb = got.br_startoff; > } else { > - /* > - * Look up the extent index for the fsb where we start shifting. We can > - * henceforth iterate with current_ext as extent list changes are locked > - * out via ilock. > - * > - * If next_fsb lies in a hole beyond which there are no extents we are > - * done. > - */ > if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, ¤t_ext, > &got)) { > *done = true; > @@ -5799,18 +5774,13 @@ xfs_bmap_insert_extents( > } > XFS_WANT_CORRUPTED_RETURN(mp, !isnullstartblock(got.br_startblock)); > > - /* Lookup the extent index at which we have to stop */ > - xfs_iext_lookup_extent(ip, ifp, stop_fsb, &stop_extent, &s); > - /* Make stop_extent exclusive of shift range */ > - stop_extent--; > - if (current_ext <= stop_extent) { > + if (stop_fsb >= got.br_startoff + got.br_blockcount) { > error = -EIO; > goto del_cursor; > } > > new_startoff = got.br_startoff + offset_shift_fsb; > - if (current_ext < total_extents - 1) { > - xfs_iext_get_extent(ifp, current_ext + 1, &next); > + if (xfs_iext_get_extent(ifp, current_ext + 1, &next)) { > if (new_startoff + got.br_blockcount > next.br_startoff) { > error = -EINVAL; > goto del_cursor; > @@ -5830,11 +5800,12 @@ xfs_bmap_insert_extents( > cur, &logflags, dfops, new_startoff); > if (error) > goto del_cursor; > - if (--current_ext == stop_extent) { > + > + if (!xfs_iext_get_extent(ifp, --current_ext, &got) || > + stop_fsb >= got.br_startoff + got.br_blockcount) { > *done = true; > goto del_cursor; > } > - xfs_iext_get_extent(ifp, current_ext, &got); > > *next_fsb = got.br_startoff; > del_cursor: > -- > 2.14.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html