Dne 23. 07. 24 v 14:51 Mikulas Patocka napsal(a):
On Wed, 17 Jul 2024, Khazhismel Kumykov wrote:
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, attempt to restore new_map and return ERESTARTSYS
when signaled.
Signed-off-by: Khazhismel Kumykov <[email protected]>
---
drivers/md/dm-ioctl.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
v2: don't leak new_map if we can't assign it back to hc.
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index c2c07bfa6471..0591455ad63c 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1181,8 +1181,27 @@ 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;
I'd like to ask why the "EINTR -> ERESTARTSYS" conversion is here and why
it isn't in dm_suspend?
What do libdevmapper+lvm maintainers think about it? Does lvm hadle EINTR
by restarting the ioctl syscall? Should we return ERESTARTSYS when suspend
is interrupted?
In general - with suspend failures - we are just stopping whole operation -
and restoring previous state - so user can run operation again.
There is no special check for exact reason of ioctl failure.
Regards
Zdenek
