> -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > owner@xxxxxxxxxxxxxxx] On Behalf Of NeilBrown > Sent: Wednesday, September 21, 2011 4:28 AM > To: Kwolek, Adam > Cc: linux-raid@xxxxxxxxxxxxxxx; Ciechanowski, Ed; Labun, Marcin > Subject: Re: [PATCH 08/14] Check if reshape can be restarted > > On Fri, 16 Sep 2011 13:54:48 +0200 Adam Kwolek <adam.kwolek@xxxxxxxxx> > wrote: > > > When reshape was invoked during initramfs start-up stage array is > > pushed in to reshape state already, so read only state cannot be set > > again. To verify if reshape continuation should be allowed sync_action > > sysfs key is tested and number of existing mdadm instances is checked > > again. > > > > Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx> > > Again, it is not at all clear to me what you are trying to protect against here... > > The "set_str ... readonly" is going to need to be changed. > > In the normal case, this is where the array is activated, but it is activated > read-only to ensure no reshape automatically starts. > > In the --continue case it is already running and reshape is suspended, so > there is no need to set it to readonly when Grow_continue is called from > Grow_continue_command. This is exactly the case. We have 2 continuation possibilities, when Grow_continue() is called: 1. Assembly when array is set to readonly state and this activates it. 2. grow --continue. Reshape is continued and array is already in reshape state, It is not possible to set readonly state again, this is why sync_action is checked For "reshape" to allow continuation for run. Conjunction with count_mdadms() /the single mdadm instance/ guards any potential race conditions. BR Adam > > NeilBrown > > > > --- > > > > Grow.c | 19 +++++++++++++++++-- > > 1 files changed, 17 insertions(+), 2 deletions(-) > > > > diff --git a/Grow.c b/Grow.c > > index 4d2c361..b331287 100644 > > --- a/Grow.c > > +++ b/Grow.c > > @@ -3714,8 +3714,23 @@ int Grow_continue(int mdfd, struct supertype > *st, struct mdinfo *info, > > int err; > > > > err = sysfs_set_str(info, NULL, "array_state", "readonly"); > > - if (err) > > - return err; > > + if (err) { > > + /* check if array is set in to reshape stare, > > + * and current mdadm instance is the only one > > + */ > > + if ((sysfs_get_str(info, NULL, "sync_action", > > + buf, 40) == 8) && > > + (count_mdadms() == 1)) { > > + dprintf("Warning: Grow_continue() cannot set array > in" > > + "to read only state [sync_action is %s].", > > + buf); > > + if (strncmp(buf, "reshape", 7)) > > + return err; > > + dprintf("Allow to continue.\n"); > > + } else > > + return err; > > + } > > + > > if (st->ss->external) { > > fmt_devname(buf, st->container_dev); > > container = buf; > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-raid" > > in the body of a message to majordomo@xxxxxxxxxxxxxxx More > majordomo > > info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
