From dc56015faff1bc9e7493c2b28302c423a02237c2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 23 Oct 2017 16:32:39 -0700 Subject: [PATCH] xfs: add a new xfs_iext_lookup_extent_before helper This helper looks up the last extent the covers space before the passed in block number. This is useful for truncate and similar operations that operate backwards over the extent list. For xfs_bunmapi it also is a slight optimization as we can return early if there are not extents at or below the end of the to be truncated range. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_bmap.c | 27 +++++++-------------------- fs/xfs/libxfs/xfs_inode_fork.c | 21 +++++++++++++++++++++ fs/xfs/libxfs/xfs_inode_fork.h | 4 ++++ fs/xfs/xfs_reflink.c | 19 +++++++------------ 4 files changed, 39 insertions(+), 32 deletions(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 26518aa..f45f05c 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -1386,17 +1386,8 @@ xfs_bmap_last_before( return error; } - if (xfs_iext_lookup_extent(ip, ifp, *last_block - 1, &idx, &got)) { - if (got.br_startoff <= *last_block - 1) - return 0; - } - - if (xfs_iext_get_extent(ifp, idx - 1, &got)) { - *last_block = got.br_startoff + got.br_blockcount; - return 0; - } - - *last_block = 0; + if (!xfs_iext_lookup_extent_before(ip, ifp, last_block, &idx, &got)) + *last_block = 0; return 0; } @@ -5171,17 +5162,13 @@ __xfs_bunmapi( } XFS_STATS_INC(mp, xs_blk_unmap); isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip); - end = start + len - 1; + end = start + len; - /* - * Check to see if the given block number is past the end of the - * file, back up to the last block if so... - */ - if (!xfs_iext_lookup_extent(ip, ifp, end, &lastx, &got)) { - ASSERT(lastx > 0); - xfs_iext_get_extent(ifp, --lastx, &got); - end = got.br_startoff + got.br_blockcount - 1; + if (!xfs_iext_lookup_extent_before(ip, ifp, &end, &lastx, &got)) { + *rlen = 0; + return 0; } + end--; logflags = 0; if (ifp->if_flags & XFS_IFBROOT) { diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 911ff79..bb63f38 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -1968,6 +1968,27 @@ xfs_iext_lookup_extent( } /* + * Returns the last extent before end, and if this extent doesn't cover + * end, update end to the end of the extent. + */ +bool +xfs_iext_lookup_extent_before( + struct xfs_inode *ip, + struct xfs_ifork *ifp, + xfs_fileoff_t *end, + xfs_extnum_t *idxp, + struct xfs_bmbt_irec *gotp) +{ + if (xfs_iext_lookup_extent(ip, ifp, *end - 1, idxp, gotp) && + gotp->br_startoff <= *end - 1) + return true; + if (!xfs_iext_get_extent(ifp, --*idxp, gotp)) + return false; + *end = gotp->br_startoff + gotp->br_blockcount; + return true; +} + +/* * Return true if there is an extent at index idx, and return the expanded * extent structure at idx in that case. Else return false. */ diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index e0c42ea..113fd42 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -183,6 +183,10 @@ void xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int); bool xfs_iext_lookup_extent(struct xfs_inode *ip, struct xfs_ifork *ifp, xfs_fileoff_t bno, xfs_extnum_t *idxp, struct xfs_bmbt_irec *gotp); +bool xfs_iext_lookup_extent_before(struct xfs_inode *ip, + struct xfs_ifork *ifp, xfs_fileoff_t *end, + xfs_extnum_t *idxp, struct xfs_bmbt_irec *gotp); + bool xfs_iext_get_extent(struct xfs_ifork *ifp, xfs_extnum_t idx, struct xfs_bmbt_irec *gotp); void xfs_iext_update_extent(struct xfs_inode *ip, int state, diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 37e603b..1205747 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -733,18 +733,13 @@ xfs_reflink_end_cow( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); - /* If there is a hole at end_fsb - 1 go to the previous extent */ - if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) || - got.br_startoff > end_fsb) { - /* - * In case of racing, overlapping AIO writes no COW extents - * might be left by the time I/O completes for the loser of - * the race. In that case we are done. - */ - if (idx <= 0) - goto out_cancel; - xfs_iext_get_extent(ifp, --idx, &got); - } + /* + * In case of racing, overlapping AIO writes no COW extents might be + * left by the time I/O completes for the loser of the race. In that + * case we are done. + */ + if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &idx, &got)) + goto out_cancel; /* Walk backwards until we're out of the I/O range... */ while (got.br_startoff + got.br_blockcount > offset_fsb) { -- 2.7.4