From e2ac836307e346969737c60075fdb01bed1af503 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 21 Jun 2018 23:24:38 -0700 Subject: [PATCH] xfs: simplify xfs_bmap_punch_delalloc_range Instead of using xfs_bmapi_read to find delalloc extents and then punch them out using xfs_bunmapi, opencode the loop to iterate over the extents and call xfs_bmap_del_extent_delay directly. This both simplifies the code and reduces the number of extent tree lookups required. Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_bmap_util.c | 93 ++++++++++++++++-------------------------- 1 file changed, 36 insertions(+), 57 deletions(-) diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index c35009a86699..c195b9d857af 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -685,12 +685,10 @@ out_unlock_iolock: } /* - * dead simple method of punching delalyed allocation blocks from a range in - * the inode. Walks a block at a time so will be slow, but is only executed in - * rare error cases so the overhead is not critical. This will always punch out - * both the start and end blocks, even if the ranges only partially overlap - * them, so it is up to the caller to ensure that partial blocks are not - * passed in. + * Dead simple method of punching delalyed allocation blocks from a range in + * the inode. This will always punch out both the start and end blocks, even + * if the ranges only partially overlap them, so it is up to the caller to + * ensure that partial blocks are not passed in. */ int xfs_bmap_punch_delalloc_range( @@ -698,63 +696,44 @@ xfs_bmap_punch_delalloc_range( xfs_fileoff_t start_fsb, xfs_fileoff_t length) { - xfs_fileoff_t remaining = length; + struct xfs_ifork *ifp = &ip->i_df; + xfs_fileoff_t end_fsb = start_fsb + length; + struct xfs_bmbt_irec got, del; + struct xfs_iext_cursor icur; int error = 0; ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); - do { - int done; - xfs_bmbt_irec_t imap; - int nimaps = 1; - xfs_fsblock_t firstblock; - struct xfs_defer_ops dfops; - - /* - * Map the range first and check that it is a delalloc extent - * before trying to unmap the range. Otherwise we will be - * trying to remove a real extent (which requires a - * transaction) or a hole, which is probably a bad idea... - */ - error = xfs_bmapi_read(ip, start_fsb, 1, &imap, &nimaps, - XFS_BMAPI_ENTIRE); - - if (error) { - /* something screwed, just bail */ - if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) { - xfs_alert(ip->i_mount, - "Failed delalloc mapping lookup ino %lld fsb %lld.", - ip->i_ino, start_fsb); - } - break; - } - if (!nimaps) { - /* nothing there */ - goto next_block; - } - if (imap.br_startblock != DELAYSTARTBLOCK) { - /* been converted, ignore */ - goto next_block; - } - WARN_ON(imap.br_blockcount == 0); - - /* - * Note: while we initialise the firstblock/dfops pair, they - * should never be used because blocks should never be - * allocated or freed for a delalloc extent and hence we need - * don't cancel or finish them after the xfs_bunmapi() call. - */ - xfs_defer_init(&dfops, &firstblock); - error = xfs_bunmapi(NULL, ip, start_fsb, 1, 0, 1, &firstblock, - &dfops, &done); + if (!(ifp->if_flags & XFS_IFEXTENTS)) { + error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); if (error) - break; + return error; + } - ASSERT(!xfs_defer_has_unfinished_work(&dfops)); -next_block: - start_fsb++; - remaining--; - } while(remaining > 0); + if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got)) + return 0; + + while (got.br_startoff + got.br_blockcount > start_fsb) { + del = got; + xfs_trim_extent(&del, start_fsb, length); + + /* + * A delete can push the cursor forward. Step back to the + * previous extent on non-delalloc or extents outside the + * target range. + */ + if (!del.br_blockcount || + !isnullstartblock(del.br_startblock)) { + if (!xfs_iext_prev_extent(ifp, &icur, &got)) + break; + continue; + } + + error = xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur, + &got, &del); + if (error || !xfs_iext_get_extent(ifp, &icur, &got)) + break; + } return error; }