do_resume when loading a new map first calls dm_suspend, which could
silently fail. When we proceeded to dm_swap_table, we would bail out
with EINVAL. Instead, restore new_map and return ERESTARTSYS when
signaled.
Signed-off-by: Khazhismel Kumykov <khazhy@xxxxxxxxxx>
---
drivers/md/dm-ioctl.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
RFC as I am rather unfamiliar with the locking semantics here - whether
we do need to re-grab hash_lock to write to an hc we previously grabbed,
and whether the device becoming unhashed while we're in this function is
really something that needs to be checked. However, this patch does fix
the issue we were seeing - we'd get EINVAL when thread in ioctl was
signaled.
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index c2c07bfa6471..b81650c6d096 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1181,8 +1181,22 @@ static int do_resume(struct dm_ioctl *param)
suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
if (param->flags & DM_NOFLUSH_FLAG)
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
- if (!dm_suspended_md(md))
- dm_suspend(md, suspend_flags);
+ if (!dm_suspended_md(md)) {
+ r = dm_suspend(md, suspend_flags);
+ if (r == -EINTR)
+ r = -ERESTARTSYS;
+ if (r) {
+ down_write(&_hash_lock);
+ hc = dm_get_mdptr(md);
+ if (!hc)
+ r = -ENXIO;
+ else
+ hc->new_map = new_map;
+ up_write(&_hash_lock);
+ dm_put(md);
+ return r;
+ }
+ }
old_size = dm_get_size(md);
old_map = dm_swap_table(md, new_map);
--
2.45.2.993.g49e7a77208-goog
