From 10ae3dc7f221f9080af5f7f5de54925d6bd248d7 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Fri, 29 May 2015 09:22:52 +1000 Subject: [PATCH] xfs: only free allocated regions of inode chunks An inode chunk is currently added to the transaction free list based on a simple fsb conversion and hardcoded chunk length. The nature of sparse chunks is such that the physical chunk of inodes on disk may consist of one or more discontiguous parts. Blocks that reside in the holes of the inode chunk are not inodes and could be allocated to any other use or not allocated at all. Refactor the existing xfs_bmap_add_free() call into the xfs_difree_inode_chunk() helper. The new helper uses the existing calculation if a chunk is not sparse. Otherwise, use the inobt record holemask to free the contiguous regions of the chunk. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_ialloc.c | 81 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 78 insertions(+), 3 deletions(-) diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c index 6451a8009874..47be76e7a124 100644 --- a/fs/xfs/libxfs/xfs_ialloc.c +++ b/fs/xfs/libxfs/xfs_ialloc.c @@ -1801,6 +1801,83 @@ out_error: return error; } +/* + * Free the blocks of an inode chunk. We must consider that the inode chunk + * might be sparse and only free the regions that are allocated as part of the + * chunk. + */ +STATIC void +xfs_difree_inode_chunk( + struct xfs_mount *mp, + xfs_agnumber_t agno, + struct xfs_inobt_rec_incore *rec, + struct xfs_bmap_free *flist) +{ + xfs_agblock_t sagbno = XFS_AGINO_TO_AGBNO(mp, rec->ir_startino); + int startidx, endidx; + int nextbit; + xfs_agblock_t agbno; + int contigblk; + DECLARE_BITMAP(holemask, XFS_INOBT_HOLEMASK_BITS); + + if (!xfs_inobt_issparse(rec->ir_holemask)) { + /* not sparse, calculate extent info directly */ + xfs_bmap_add_free(XFS_AGB_TO_FSB(mp, agno, + XFS_AGINO_TO_AGBNO(mp, rec->ir_startino)), + mp->m_ialloc_blks, flist, mp); + return; + } + + /* holemask is only 16-bits (fits in an unsigned long) */ + ASSERT(sizeof(rec->ir_holemask) <= sizeof(holemask[0])); + holemask[0] = rec->ir_holemask; + + /* + * Find contiguous ranges of zeroes (i.e., allocated regions) in the + * holemask and convert the start/end index of each range to an extent. + * We start with the start and end index both pointing at the first 0 in + * the mask. + */ + startidx = endidx = find_first_zero_bit(holemask, + XFS_INOBT_HOLEMASK_BITS); + nextbit = startidx + 1; + while (startidx < XFS_INOBT_HOLEMASK_BITS) { + nextbit = find_next_zero_bit(holemask, XFS_INOBT_HOLEMASK_BITS, + nextbit); + /* + * If the next zero bit is contiguous, update the end index of + * the current range and continue. + */ + if (nextbit != XFS_INOBT_HOLEMASK_BITS && + nextbit == endidx + 1) { + endidx = nextbit; + goto next; + } + + /* + * nextbit is not contiguous with the current end index. Convert + * the current start/end to an extent and add it to the free + * list. + */ + agbno = sagbno + (startidx * XFS_INODES_PER_HOLEMASK_BIT) / + mp->m_sb.sb_inopblock; + contigblk = ((endidx - startidx + 1) * + XFS_INODES_PER_HOLEMASK_BIT) / + mp->m_sb.sb_inopblock; + + ASSERT(agbno % mp->m_sb.sb_spino_align == 0); + ASSERT(contigblk % mp->m_sb.sb_spino_align == 0); + xfs_bmap_add_free(XFS_AGB_TO_FSB(mp, agno, agbno), contigblk, + flist, mp); + + /* reset range to current bit and carry on... */ + startidx = endidx = nextbit; + +next: + nextbit++; + } +} + STATIC int xfs_difree_inobt( struct xfs_mount *mp, @@ -1895,9 +1972,7 @@ xfs_difree_inobt( goto error0; } - xfs_bmap_add_free(XFS_AGB_TO_FSB(mp, agno, - XFS_AGINO_TO_AGBNO(mp, rec.ir_startino)), - mp->m_ialloc_blks, flist, mp); + xfs_difree_inode_chunk(mp, agno, &rec, flist); } else { *deleted = 0; -- 2.20.1