| Message ID | 20201019064048.6591-8-chandanrlinux@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Bail out if transaction can cause extent count to overflow | expand |
On 10/18/20 11:40 PM, Chandan Babu R wrote: > Moving an extent to data fork can cause a sub-interval of an existing > extent to be unmapped. This will increase extent count by 1. Mapping in > the new extent can increase the extent count by 1 again i.e. > | Old extent | New extent | Old extent | > Hence number of extents increases by 2. > Looks ok to me Reviewed-by: Allison Henderson <allison.henderson@oracle.com> > Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> > --- > fs/xfs/libxfs/xfs_inode_fork.h | 9 +++++++++ > fs/xfs/xfs_reflink.c | 5 +++++ > 2 files changed, 14 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h > index afb647e1e3fa..b99e67e7b59b 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.h > +++ b/fs/xfs/libxfs/xfs_inode_fork.h > @@ -78,6 +78,15 @@ struct xfs_ifork { > */ > #define XFS_IEXT_WRITE_UNWRITTEN_CNT (2) > > +/* > + * Moving an extent to data fork can cause a sub-interval of an existing extent > + * to be unmapped. This will increase extent count by 1. Mapping in the new > + * extent can increase the extent count by 1 again i.e. > + * | Old extent | New extent | Old extent | > + * Hence number of extents increases by 2. > + */ > +#define XFS_IEXT_REFLINK_END_COW_CNT (2) > + > /* > * Fork handling. > */ > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index 16098dc42add..4f0198f636ad 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -628,6 +628,11 @@ xfs_reflink_end_cow_extent( > xfs_ilock(ip, XFS_ILOCK_EXCL); > xfs_trans_ijoin(tp, ip, 0); > > + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, > + XFS_IEXT_REFLINK_END_COW_CNT); > + if (error) > + goto out_cancel; > + > /* > * In case of racing, overlapping AIO writes no COW extents might be > * left by the time I/O completes for the loser of the race. In that >
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index afb647e1e3fa..b99e67e7b59b 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -78,6 +78,15 @@ struct xfs_ifork { */ #define XFS_IEXT_WRITE_UNWRITTEN_CNT (2) +/* + * Moving an extent to data fork can cause a sub-interval of an existing extent + * to be unmapped. This will increase extent count by 1. Mapping in the new + * extent can increase the extent count by 1 again i.e. + * | Old extent | New extent | Old extent | + * Hence number of extents increases by 2. + */ +#define XFS_IEXT_REFLINK_END_COW_CNT (2) + /* * Fork handling. */ diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 16098dc42add..4f0198f636ad 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -628,6 +628,11 @@ xfs_reflink_end_cow_extent( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_REFLINK_END_COW_CNT); + if (error) + goto out_cancel; + /* * In case of racing, overlapping AIO writes no COW extents might be * left by the time I/O completes for the loser of the race. In that