Commits
Jonathan Brassow committed da1e148803e
dm raid: fix incorrect sync_ratio when degraded
Upstream commit 4102d9de6d375 ("dm raid: fix rs_get_progress()
synchronization state/ratio") in combination with commit 7c29744ecce
("dm raid: simplify rs_get_progress()") introduced a regression by
incorrectly reporting a sync_ratio of 0 for degraded raid sets. This
caused lvm2 to fail to repair raid legs automatically.
Fix by identifying the degraded state by checking the MD_RECOVERY_INTR
flag and returning mddev->recovery_cp in case it is set.
MD sets recovery = [ MD_RECOVERY_RECOVER MD_RECOVERY_INTR
MD_RECOVERY_NEEDED ] when a RAID member fails. It then shuts down any
sync thread that is running and leaves us with all MD_RECOVERY_* flags
cleared. The bug occurs if a status is requested in the short time it
takes to shut down any sync thread and clear the flags, because we were
keying in on the MD_RECOVERY_NEEDED - understanding it to be the initial
phase of a “recover” sync thread. However, this is an incorrect
interpretation if MD_RECOVERY_INTR is also set.
This also explains why the bug only happened when automatic repair was
enabled and not a normal ‘manual’ method. It is impossible to react
quick enough to hit the problematic window without it being automated.
Fix passes automatic repair tests.
Fixes: 7c29744ecce ("dm raid: simplify rs_get_progress()")
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>