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 <khazhy@xxxxxxxxxx> --- 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
