Re: [RFC][PATCH 4/7] UBC: syscalls (user interface)

From: Kirill Korotaev
Date: Thu Aug 17 2006 - 08:00:09 EST

Add the following system calls for UB management:
1. sys_getluid - get current UB id
2. sys_setluid - changes exec_ and fork_ UBs on current
3. sys_setublimit - set limits for resources consumtions

Why not have another system call for getting the current limits?
will add sys_getublimit().

But as I said in previous mail, configfs seems like a better choice for
user interface. That way user has to go to one place to read/write
limits, see the current usage and other stats.
Check another email about interfaces. I have arguments against it :/

Signed-Off-By: Pavel Emelianov <xemul@xxxxx>
Signed-Off-By: Kirill Korotaev <dev@xxxxx>


+ * The setbeanlimit syscall
+ */
+asmlinkage long sys_setublimit(uid_t uid, unsigned long resource,
+ unsigned long *limits)

+ ub = beancounter_findcreate(uid, NULL, 0);
+ if (ub == NULL)
+ goto out;
+ spin_lock_irqsave(&ub->ub_lock, flags);
+ ub->ub_parms[resource].barrier = new_limits[0];
+ ub->ub_parms[resource].limit = new_limits[1];
+ spin_unlock_irqrestore(&ub->ub_lock, flags);

I think there should be a check here for seeing if the new limits are
lower than the current usage of a resource. If so then take appropriate
any idea what exact action to add here?
Looks like can be added when needed, agree?


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