From 72d552854b96b3e2a2c547a5e5a798a17dfda650 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 22 Jun 2015 10:04:42 +1000 Subject: [PATCH] xfs: factor out free space extent length check The longest extent length checks in xfs_alloc_fix_freelist() are now essentially identical. Factor them out into a helper function, so we know they are checking exactly the same thing before and after we lock the AGF. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_alloc.c | 71 +++++++++++++++++++++++++++++------------------ 1 file changed, 44 insertions(+), 27 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 9b3e3681dfa9..c548bb022aa6 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1839,6 +1839,39 @@ xfs_alloc_longest_free_extent( } /* + * Check if the operation we are fixing up the freelist for should go ahead or + * not. If we are freeing blocks, we always allow it, otherwise the allocation + * is dependent on whether the size and shape of free space available will + * permit the requested allocation to take place. + */ +static bool +xfs_alloc_space_available( + struct xfs_alloc_arg *args, + xfs_extlen_t min_free, + int flags) +{ + struct xfs_perag *pag = args->pag; + xfs_extlen_t longest; + int available; + + if (flags & XFS_ALLOC_FLAG_FREEING) + return true; + + /* do we have enough contiguous free space for the allocation? */ + longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free); + if ((args->minlen + args->alignment + args->minalignslop - 1) > longest) + return false; + + /* do have enough free space remaining for the allocation? */ + available = (int)(pag->pagf_freeblks + pag->pagf_flcount - + min_free - args->total); + if (available < (int)args->minleft) + return false; + + return true; +} + +/* * Decide whether to use this allocation group for this allocation. * If so, fix up the btree freelist's size. */ @@ -1851,7 +1884,6 @@ xfs_alloc_fix_freelist( xfs_buf_t *agflbp;/* agfl buffer pointer */ xfs_agblock_t bno; /* freelist block */ int error; /* error result code */ - xfs_extlen_t longest;/* longest extent in allocation group */ xfs_mount_t *mp; /* file system mount point structure */ xfs_extlen_t need; /* total blocks needed in freelist */ xfs_perag_t *pag; /* per-ag information structure */ @@ -1887,22 +1919,12 @@ xfs_alloc_fix_freelist( return 0; } - if (!(flags & XFS_ALLOC_FLAG_FREEING)) { - /* - * If it looks like there isn't a long enough extent, or enough - * total blocks, reject it. - */ - need = XFS_MIN_FREELIST_PAG(pag, mp); - longest = xfs_alloc_longest_free_extent(mp, pag, need); - if ((args->minlen + args->alignment + args->minalignslop - 1) > - longest || - ((int)(pag->pagf_freeblks + pag->pagf_flcount - - need - args->total) < (int)args->minleft)) { - if (agbp) - xfs_trans_brelse(tp, agbp); - args->agbp = NULL; - return 0; - } + need = XFS_MIN_FREELIST_PAG(pag, mp); + if (!xfs_alloc_space_available(args, need, flags)) { + if (agbp) + xfs_trans_brelse(tp, agbp); + args->agbp = NULL; + return 0; } /* @@ -1924,17 +1946,12 @@ xfs_alloc_fix_freelist( /* If there isn't enough total space or single-extent, reject it. */ need = XFS_MIN_FREELIST_PAG(pag, mp); - if (!(flags & XFS_ALLOC_FLAG_FREEING)) { - longest = xfs_alloc_longest_free_extent(mp, pag, need); - if ((args->minlen + args->alignment + args->minalignslop - 1) > - longest || - ((int)(pag->pagf_freeblks + pag->pagf_flcount - - need - args->total) < (int)args->minleft)) { - xfs_trans_brelse(tp, agbp); - args->agbp = NULL; - return 0; - } + if (!xfs_alloc_space_available(args, need, flags)) { + xfs_trans_brelse(tp, agbp); + args->agbp = NULL; + return 0; } + /* * Make the freelist shorter if it's too long. * -- 2.11.0