On Tue, Jul 09, 2019 at 06:59:43AM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > There's a subtle unit conversion error when we increment the INUMBERS > cursor at the end of xfs_inumbers_walk. If there's an inode chunk at > the very end of the AG /and/ the AG size is a perfect power of two, that > means we can have inodes, that means that the startino of that last "...is a perfect power of two, the startino of that last chunk..." --D > chunk (which is in units of AG inodes) will be 63 less than (1 << > agino_log). If we add XFS_INODES_PER_CHUNK to the startino, we end up > with a startino that's larger than (1 << agino_log) and when we convert > that back to fs inode units we'll rip off that upper bit and wind up > back at the start of the AG. > > Fix this by converting to units of fs inodes before adding > XFS_INODES_PER_CHUNK so that we'll harmlessly end up pointing to the > next AG. > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > --- > fs/xfs/xfs_itable.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c > index cda8ae94480c..a8a06bb78ea8 100644 > --- a/fs/xfs/xfs_itable.c > +++ b/fs/xfs/xfs_itable.c > @@ -338,15 +338,14 @@ xfs_inumbers_walk( > .xi_version = XFS_INUMBERS_VERSION_V5, > }; > struct xfs_inumbers_chunk *ic = data; > - xfs_agino_t agino; > int error; > > error = ic->formatter(ic->breq, &inogrp); > if (error && error != XFS_IBULK_ABORT) > return error; > > - agino = irec->ir_startino + XFS_INODES_PER_CHUNK; > - ic->breq->startino = XFS_AGINO_TO_INO(mp, agno, agino); > + ic->breq->startino = XFS_AGINO_TO_INO(mp, agno, irec->ir_startino) + > + XFS_INODES_PER_CHUNK; > return error; > } >
