xfs: remove nr_to_write writeback windup.

[safe/jmp/linux-2.6] / kernel / res_counter.c

diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index efbfc0f..c7eaa37 100644 (file)
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -12,11 +12,14 @@
 #include <linux/fs.h>
 #include <linux/res_counter.h>
 #include <linux/uaccess.h>
+#include <linux/mm.h>
 
-void res_counter_init(struct res_counter *counter)
+void res_counter_init(struct res_counter *counter, struct res_counter *parent)
 {
        spin_lock_init(&counter->lock);
-       counter->limit = (unsigned long long)LLONG_MAX;
+       counter->limit = RESOURCE_MAX;
+       counter->soft_limit = RESOURCE_MAX;
+       counter->parent = parent;
 }
 
 int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
@@ -27,17 +30,39 @@ int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
        }
 
        counter->usage += val;
+       if (counter->usage > counter->max_usage)
+               counter->max_usage = counter->usage;
        return 0;
 }
 
-int res_counter_charge(struct res_counter *counter, unsigned long val)
+int res_counter_charge(struct res_counter *counter, unsigned long val,
+                       struct res_counter **limit_fail_at)
 {
        int ret;
        unsigned long flags;
-
-       spin_lock_irqsave(&counter->lock, flags);
-       ret = res_counter_charge_locked(counter, val);
-       spin_unlock_irqrestore(&counter->lock, flags);
+       struct res_counter *c, *u;
+
+       *limit_fail_at = NULL;
+       local_irq_save(flags);
+       for (c = counter; c != NULL; c = c->parent) {
+               spin_lock(&c->lock);
+               ret = res_counter_charge_locked(c, val);
+               spin_unlock(&c->lock);
+               if (ret < 0) {
+                       *limit_fail_at = c;
+                       goto undo;
+               }
+       }
+       ret = 0;
+       goto done;
+undo:
+       for (u = counter; u != c; u = u->parent) {
+               spin_lock(&u->lock);
+               res_counter_uncharge_locked(u, val);
+               spin_unlock(&u->lock);
+       }
+done:
+       local_irq_restore(flags);
        return ret;
 }
 
@@ -52,10 +77,15 @@ void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
 void res_counter_uncharge(struct res_counter *counter, unsigned long val)
 {
        unsigned long flags;
+       struct res_counter *c;
 
-       spin_lock_irqsave(&counter->lock, flags);
-       res_counter_uncharge_locked(counter, val);
-       spin_unlock_irqrestore(&counter->lock, flags);
+       local_irq_save(flags);
+       for (c = counter; c != NULL; c = c->parent) {
+               spin_lock(&c->lock);
+               res_counter_uncharge_locked(c, val);
+               spin_unlock(&c->lock);
+       }
+       local_irq_restore(flags);
 }
 
 
@@ -65,10 +95,14 @@ res_counter_member(struct res_counter *counter, int member)
        switch (member) {
        case RES_USAGE:
                return &counter->usage;
+       case RES_MAX_USAGE:
+               return &counter->max_usage;
        case RES_LIMIT:
                return &counter->limit;
        case RES_FAILCNT:
                return &counter->failcnt;
+       case RES_SOFT_LIMIT:
+               return &counter->soft_limit;
        };
 
        BUG();
@@ -92,44 +126,52 @@ ssize_t res_counter_read(struct res_counter *counter, int member,
                        pos, buf, s - buf);
 }
 
-ssize_t res_counter_write(struct res_counter *counter, int member,
-               const char __user *userbuf, size_t nbytes, loff_t *pos,
-               int (*write_strategy)(char *st_buf, unsigned long long *val))
+u64 res_counter_read_u64(struct res_counter *counter, int member)
 {
-       int ret;
-       char *buf, *end;
-       unsigned long flags;
-       unsigned long long tmp, *val;
+       return *res_counter_member(counter, member);
+}
+
+int res_counter_memparse_write_strategy(const char *buf,
+                                       unsigned long long *res)
+{
+       char *end;
+
+       /* return RESOURCE_MAX(unlimited) if "-1" is specified */
+       if (*buf == '-') {
+               *res = simple_strtoull(buf + 1, &end, 10);
+               if (*res != 1 || *end != '\0')
+                       return -EINVAL;
+               *res = RESOURCE_MAX;
+               return 0;
+       }
 
-       buf = kmalloc(nbytes + 1, GFP_KERNEL);
-       ret = -ENOMEM;
-       if (buf == NULL)
-               goto out;
+       /* FIXME - make memparse() take const char* args */
+       *res = memparse((char *)buf, &end);
+       if (*end != '\0')
+               return -EINVAL;
 
-       buf[nbytes] = '\0';
-       ret = -EFAULT;
-       if (copy_from_user(buf, userbuf, nbytes))
-               goto out_free;
+       *res = PAGE_ALIGN(*res);
+       return 0;
+}
 
-       ret = -EINVAL;
+int res_counter_write(struct res_counter *counter, int member,
+                     const char *buf, write_strategy_fn write_strategy)
+{
+       char *end;
+       unsigned long flags;
+       unsigned long long tmp, *val;
 
-       strstrip(buf);
        if (write_strategy) {
-               if (write_strategy(buf, &tmp)) {
-                       goto out_free;
-               }
+               if (write_strategy(buf, &tmp))
+                       return -EINVAL;
        } else {
                tmp = simple_strtoull(buf, &end, 10);
                if (*end != '\0')
-                       goto out_free;
+                       return -EINVAL;
        }
        spin_lock_irqsave(&counter->lock, flags);
        val = res_counter_member(counter, member);
        *val = tmp;
        spin_unlock_irqrestore(&counter->lock, flags);
-       ret = nbytes;
-out_free:
-       kfree(buf);
-out:
-       return ret;
+       return 0;
 }