On Fri, Sep 18, 2020 at 03:17:52PM +0530, Chandan Babu R wrote: > The extent mapping the file offset at which a hole has to be > inserted will be split into two extents causing extent count to > increase by 1. > > Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx> > --- > fs/xfs/libxfs/xfs_inode_fork.h | 7 +++++++ > fs/xfs/xfs_bmap_item.c | 5 +++++ > fs/xfs/xfs_bmap_util.c | 10 ++++++++++ > 3 files changed, 22 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h > index 7fc2b129a2e7..bcac769a7df6 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.h > +++ b/fs/xfs/libxfs/xfs_inode_fork.h > @@ -40,6 +40,13 @@ struct xfs_ifork { > */ > #define XFS_IEXT_ADD_NOSPLIT_CNT (1) > > +/* > + * Punching out an extent from the middle of an existing extent can cause the > + * extent count to increase by 1. > + * i.e. | Old extent | Hole | Old extent | > + */ > +#define XFS_IEXT_PUNCH_HOLE_CNT (1) > + > /* > * Fork handling. > */ > diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c > index ec3691372e7c..5c7d08da8ff1 100644 > --- a/fs/xfs/xfs_bmap_item.c > +++ b/fs/xfs/xfs_bmap_item.c > @@ -519,6 +519,11 @@ xfs_bui_item_recover( > } > xfs_trans_ijoin(tp, ip, 0); > > + error = xfs_iext_count_may_overflow(ip, whichfork, > + XFS_IEXT_PUNCH_HOLE_CNT); I think this ought to be XFS_IEXT_ADD_NOSPLIT_CNT if bui_type is XFS_BMAP_MAP and XFS_IEXT_PUNCH_HOLE_CNT if XFS_BMAP_UNMAP. Whoever created the BUI should have called xfs_iext_count_may_overflow before logging the BUI (and hence this should never occur) but it does pay to be careful. :) The rest of the logic in the patch looks ok. --D > + if (error) > + goto err_inode; > + > count = bmap->me_len; > error = xfs_trans_log_finish_bmap_update(tp, budp, type, ip, whichfork, > bmap->me_startoff, bmap->me_startblock, &count, state); > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index dcd6e61df711..0776abd0103c 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -891,6 +891,11 @@ xfs_unmap_extent( > > xfs_trans_ijoin(tp, ip, 0); > > + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, > + XFS_IEXT_PUNCH_HOLE_CNT); > + if (error) > + goto out_trans_cancel; > + > error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done); > if (error) > goto out_trans_cancel; > @@ -1176,6 +1181,11 @@ xfs_insert_file_space( > xfs_ilock(ip, XFS_ILOCK_EXCL); > xfs_trans_ijoin(tp, ip, 0); > > + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, > + XFS_IEXT_PUNCH_HOLE_CNT); > + if (error) > + goto out_trans_cancel; > + > /* > * The extent shifting code works on extent granularity. So, if stop_fsb > * is not the starting block of extent, we need to split the extent at > -- > 2.28.0 >