From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 07/12] cgroup: unify cgroup_write_X64() and cgroup_write_string() Date: Wed, 27 Nov 2013 18:42:34 -0500 Message-ID: <1385595759-17656-8-git-send-email-tj@kernel.org> References: <1385595759-17656-1-git-send-email-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=8xh1tC1JuveCDjJE5A8mXFuAWqc/PSAmajThRuElKVM=; b=bgdviLrGRoS505IsmZCFsPhNKyRmh73QAa7QaQB0X49arpBHgCTxFIb6aFdGy1qqEM tlJzy50g26ZiUtZb0z66WHMr2MbE5OhTTAwjB6nkJUxV/ldftmHDgAZUXI5SWNWV4jDV tuc+dQ5rkEDT0J2RDcB6+/qVyBLw4tGNXwAv/dbVqT7jqkLoHW32D6evgGtRxVam6Fkq jJUV2nlQ3FBkn832Dza+LX2dunPAtodvcV0kwLQuYUvjRd3KeuSO78HAfWd92TOTv/YA IghNR5FUxYRuwJm8NmSYd8In4JfktPKzkzV3J5UGCmHTE2RSvQCN4QaGU8LIjNzw/dWs WG7Q== In-Reply-To: <1385595759-17656-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-AlSwsSmVLrQ@public.gmane.org, bsingharora-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org, daniel.wagner-98C5kh4wR6ohFhg+JK9F0w@public.gmane.org, arozansk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Tejun Heo cgroup_write_X64() and cgroup_write_string() both implement about the same buffering logic. Unify the two into cgroup_file_write() which always allocates dynamic buffer for simplicity and uses kstrto*() instead of simple_strto*(). This patch doesn't make any visible behavior changes except for possibly different error value from kstrsto*(). Signed-off-by: Tejun Heo --- kernel/cgroup.c | 112 ++++++++++++++++++-------------------------------------- 1 file changed, 36 insertions(+), 76 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 3592515..23abe8e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2249,90 +2249,50 @@ static int cgroup_sane_behavior_show(struct cgroup_subsys_state *css, /* A buffer size big enough for numbers or short strings */ #define CGROUP_LOCAL_BUFFER_SIZE 64 -static ssize_t cgroup_write_X64(struct cgroup_subsys_state *css, - struct cftype *cft, struct file *file, - const char __user *userbuf, size_t nbytes, - loff_t *unused_ppos) -{ - char buffer[CGROUP_LOCAL_BUFFER_SIZE]; - int retval = 0; - char *end; - - if (!nbytes) - return -EINVAL; - if (nbytes >= sizeof(buffer)) - return -E2BIG; - if (copy_from_user(buffer, userbuf, nbytes)) - return -EFAULT; - - buffer[nbytes] = 0; /* nul-terminate */ - if (cft->write_u64) { - u64 val = simple_strtoull(strstrip(buffer), &end, 0); - if (*end) - return -EINVAL; - retval = cft->write_u64(css, cft, val); - } else { - s64 val = simple_strtoll(strstrip(buffer), &end, 0); - if (*end) - return -EINVAL; - retval = cft->write_s64(css, cft, val); - } - if (!retval) - retval = nbytes; - return retval; -} - -static ssize_t cgroup_write_string(struct cgroup_subsys_state *css, - struct cftype *cft, struct file *file, - const char __user *userbuf, size_t nbytes, - loff_t *unused_ppos) +static ssize_t cgroup_file_write(struct file *file, const char __user *userbuf, + size_t nbytes, loff_t *ppos) { - char local_buffer[CGROUP_LOCAL_BUFFER_SIZE]; - int retval = 0; - size_t max_bytes = cft->max_write_len; - char *buffer = local_buffer; + struct cfent *cfe = __d_cfe(file->f_dentry); + struct cftype *cft = __d_cft(file->f_dentry); + struct cgroup_subsys_state *css = cfe->css; + size_t max_bytes = cft->max_write_len ?: CGROUP_LOCAL_BUFFER_SIZE - 1; + char *buf; + int ret; - if (!max_bytes) - max_bytes = sizeof(local_buffer) - 1; if (nbytes >= max_bytes) return -E2BIG; - /* Allocate a dynamic buffer if we need one */ - if (nbytes >= sizeof(local_buffer)) { - buffer = kmalloc(nbytes + 1, GFP_KERNEL); - if (buffer == NULL) - return -ENOMEM; - } - if (nbytes && copy_from_user(buffer, userbuf, nbytes)) { - retval = -EFAULT; - goto out; - } - buffer[nbytes] = 0; /* nul-terminate */ - retval = cft->write_string(css, cft, strstrip(buffer)); - if (!retval) - retval = nbytes; -out: - if (buffer != local_buffer) - kfree(buffer); - return retval; -} + buf = kmalloc(nbytes + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; -static ssize_t cgroup_file_write(struct file *file, const char __user *buf, - size_t nbytes, loff_t *ppos) -{ - struct cfent *cfe = __d_cfe(file->f_dentry); - struct cftype *cft = __d_cft(file->f_dentry); - struct cgroup_subsys_state *css = cfe->css; + if (copy_from_user(buf, userbuf, nbytes)) { + ret = -EFAULT; + goto out_free; + } - if (cft->write_u64 || cft->write_s64) - return cgroup_write_X64(css, cft, file, buf, nbytes, ppos); - if (cft->write_string) - return cgroup_write_string(css, cft, file, buf, nbytes, ppos); - if (cft->trigger) { - int ret = cft->trigger(css, (unsigned int)cft->private); - return ret ? ret : nbytes; + buf[nbytes] = '\0'; + + if (cft->write_string) { + ret = cft->write_string(css, cft, strstrip(buf)); + } else if (cft->write_u64) { + unsigned long long v; + ret = kstrtoull(buf, 0, &v); + if (!ret) + ret = cft->write_u64(css, cft, v); + } else if (cft->write_s64) { + long long v; + ret = kstrtoll(buf, 0, &v); + if (!ret) + ret = cft->write_s64(css, cft, v); + } else if (cft->trigger) { + ret = cft->trigger(css, (unsigned int)cft->private); + } else { + ret = -EINVAL; } - return -EINVAL; +out_free: + kfree(buf); + return ret ?: nbytes; } static ssize_t cgroup_read_u64(struct cgroup_subsys_state *css, -- 1.8.4.2