switch /dev/kmsg to ->write_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 1ce7706..7a6e694 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -519,14 +519,13 @@ struct devkmsg_user {
        char buf[8192];
 };
 
-static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
-                             unsigned long count, loff_t pos)
+static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
 {
        char *buf, *line;
        int i;
        int level = default_message_loglevel;
        int facility = 1;       /* LOG_USER */
-       size_t len = iov_length(iv, count);
+       size_t len = iocb->ki_nbytes;
        ssize_t ret = len;
 
        if (len > LOG_LINE_MAX)
@@ -535,13 +534,10 @@ static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
        if (buf == NULL)
                return -ENOMEM;
 
-       line = buf;
-       for (i = 0; i < count; i++) {
-               if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
-                       ret = -EFAULT;
-                       goto out;
-               }
-               line += iv[i].iov_len;
+       buf[len] = '\0';
+       if (copy_from_iter(buf, len, from) != len) {
+               kfree(buf);
+               return -EFAULT;
        }
 
        /*
@@ -567,10 +563,8 @@ static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
                        line = endp;
                }
        }
-       line[len] = '\0';
 
        printk_emit(facility, level, NULL, 0, "%s", line);
-out:
        kfree(buf);
        return ret;
 }
@@ -802,7 +796,7 @@ static int devkmsg_release(struct inode *inode, struct file *file)
 const struct file_operations kmsg_fops = {
        .open = devkmsg_open,
        .read = devkmsg_read,
-       .aio_write = devkmsg_writev,
+       .write_iter = devkmsg_write,
        .llseek = devkmsg_llseek,
        .poll = devkmsg_poll,
        .release = devkmsg_release,