[PATCH] libxfs: disallow filesystems with reverse mapping and reflink and realtime

Darrick J. Wong
2020-09-30T14:58:47Z

From: Darrick J. Wong <darrick.wong@oracle.com>

Neither the kernel nor the code in xfsprogs support filesystems that
have (either reverse mapping btrees or reflink) enabled and a realtime
volume configured. The kernel rejects such combinations and mkfs
refuses to format such a config, but xfsprogs doesn't check and can do
Bad Things, so port those checks before someone shreds their filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
libxfs/init.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/libxfs/init.c b/libxfs/init.c
index cb8967bc77d4..1a966084ffea 100644
--- a/libxfs/init.c
+++ b/libxfs/init.c
@@ -724,6 +724,20 @@ libxfs_mount(
exit(1);
}

+ if (xfs_sb_version_hasreflink(sbp) && sbp->sb_rblocks) {
+ fprintf(stderr,
+ _("%s: Reflink not compatible with realtime device. Please try a newer xfsprogs.\n"),
+ progname);
+ exit(1);
+ }
+
+ if (xfs_sb_version_hasrmapbt(sbp) && sbp->sb_rblocks) {
+ fprintf(stderr,
+ _("%s: Reverse mapping btree not compatible with realtime device. Please try a newer xfsprogs.\n"),
+ progname);
+ exit(1);
+ }
+
xfs_da_mount(mp);

if (xfs_sb_version_hasattr2(&mp->m_sb))