cgroup files: convert res_counter_write() to be a cgroups write_string() handler
Currently res_counter_write() is a raw file handler even though it's ultimately taking a number, since in some cases it wants to pre-process the string when converting it to a number. This patch converts res_counter_write() from a raw file handler to a write_string() handler; this allows some of the boilerplate copying/locking/checking to be removed, and simplies the cleanup path, since these functions are now performed by the cgroups framework. [lizf@cn.fujitsu.com: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:

committed by
Linus Torvalds

parent
f92523e3a7
commit
856c13aa1f
@@ -13,6 +13,7 @@
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#include <linux/slab.h>
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#include <linux/res_counter.h>
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#include <linux/uaccess.h>
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#include <linux/mm.h>
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void res_counter_init(struct res_counter *counter)
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{
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@@ -102,44 +103,37 @@ u64 res_counter_read_u64(struct res_counter *counter, int member)
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return *res_counter_member(counter, member);
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}
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ssize_t res_counter_write(struct res_counter *counter, int member,
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const char __user *userbuf, size_t nbytes, loff_t *pos,
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int (*write_strategy)(char *st_buf, unsigned long long *val))
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int res_counter_memparse_write_strategy(const char *buf,
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unsigned long long *res)
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{
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int ret;
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char *buf, *end;
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char *end;
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/* FIXME - make memparse() take const char* args */
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*res = memparse((char *)buf, &end);
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if (*end != '\0')
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return -EINVAL;
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*res = PAGE_ALIGN(*res);
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return 0;
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}
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int res_counter_write(struct res_counter *counter, int member,
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const char *buf, write_strategy_fn write_strategy)
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{
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char *end;
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unsigned long flags;
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unsigned long long tmp, *val;
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buf = kmalloc(nbytes + 1, GFP_KERNEL);
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ret = -ENOMEM;
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if (buf == NULL)
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goto out;
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buf[nbytes] = '\0';
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ret = -EFAULT;
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if (copy_from_user(buf, userbuf, nbytes))
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goto out_free;
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ret = -EINVAL;
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strstrip(buf);
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if (write_strategy) {
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if (write_strategy(buf, &tmp)) {
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goto out_free;
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}
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if (write_strategy(buf, &tmp))
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return -EINVAL;
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} else {
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tmp = simple_strtoull(buf, &end, 10);
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if (*end != '\0')
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goto out_free;
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return -EINVAL;
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}
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spin_lock_irqsave(&counter->lock, flags);
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val = res_counter_member(counter, member);
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*val = tmp;
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spin_unlock_irqrestore(&counter->lock, flags);
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ret = nbytes;
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out_free:
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kfree(buf);
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out:
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return ret;
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return 0;
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}
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