console: split console setup into logical parts

The lxc_console_create() function used to munge the ringbuffer setup and the
log file setup already. This made somewhat sense when we didn't have a separate
ringbuffer log file. Now it's just plain confusing. So split this into logical
helpers that future maintainers can understand:

- lxc_console_create_log_file()
- lxc_console_create_ringbuf(console);
- lxc_console_create_ringbuf_log_file(console);

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/console.c b/src/lxc/console.c
index d83b3830e08bc4324117e59150ea78b2fd4a4079..14fe4024020c1e93c1286c4801ed2b241e539a4f 100644 (file)
--- a/src/lxc/console.c
+++ b/src/lxc/console.c
@@ -552,7 +552,6 @@ out:
 
 int lxc_console_write_ringbuffer(struct lxc_console *console)
 {
-       int fd;
        char *r_addr;
        ssize_t ret;
        uint64_t used;
@@ -565,16 +564,8 @@ int lxc_console_write_ringbuffer(struct lxc_console *console)
        if (used == 0)
                return 0;
 
-       fd = lxc_unpriv(open(console->buffer_log_file, O_CLOEXEC | O_RDWR | O_CREAT | O_TRUNC, 0600));
-       if (fd < 0) {
-               SYSERROR("Failed to open console log file \"%s\"", console->buffer_log_file);
-               return -EIO;
-       }
-       DEBUG("Using \"%s\" as console log file", console->buffer_log_file);
-
        r_addr = lxc_ringbuf_get_read_addr(buf);
-       ret = lxc_write_nointr(fd, r_addr, used);
-       close(fd);
+       ret = lxc_write_nointr(console->buffer_log_file_fd, r_addr, used);
        if (ret < 0)
                return -EIO;
 
@@ -606,6 +597,30 @@ void lxc_console_delete(struct lxc_console *console)
        console->master = -1;
        console->slave = -1;
        console->log_fd = -1;
+       if (console->buffer_log_file_fd >= 0)
+               close(console->buffer_log_file_fd);
+       console->buffer_log_file_fd = -1;
+}
+
+/* This is the console ringbuffer log file. Please note that the console
+ * ringbuffer log file is (implementation wise not content wise) independent of
+ * the console log file.
+ */
+static int lxc_console_create_ringbuf_log_file(struct lxc_console *console)
+{
+       if (!console->buffer_log_file)
+               return 0;
+
+       console->buffer_log_file_fd = lxc_unpriv(open(console->buffer_log_file,
+                           O_CLOEXEC | O_RDWR | O_CREAT | O_TRUNC, 0600));
+       if (console->buffer_log_file_fd < 0) {
+               SYSERROR("Failed to open console ringbuffer log file \"%s\"",
+                        console->buffer_log_file);
+               return -EIO;
+       }
+
+       DEBUG("Using \"%s\" as console ringbuffer log file", console->buffer_log_file);
+       return 0;
 }
 
 /**
@@ -613,7 +628,7 @@ void lxc_console_delete(struct lxc_console *console)
  * register a handler for the console's masterfd when we create the mainloop
  * the console handler needs to see an allocated ringbuffer.
  */
-static int lxc_setup_console_ringbuf(struct lxc_console *console)
+static int lxc_console_create_ringbuf(struct lxc_console *console)
 {
        int ret;
        struct lxc_ringbuf *buf = &console->ringbuf;
@@ -655,6 +670,25 @@ static int lxc_setup_console_ringbuf(struct lxc_console *console)
        return 0;
 }
 
+/**
+ * This is the console log file. Please note that the console log file is
+ * (implementation wise not content wise) independent of the console ringbuffer.
+ */
+static int lxc_console_create_log_file(struct lxc_console *console)
+{
+       if (!console->log_path)
+               return 0;
+
+       console->log_fd = lxc_unpriv(open(console->log_path, O_CLOEXEC | O_RDWR | O_CREAT | O_APPEND, 0600));
+       if (console->log_fd < 0) {
+               SYSERROR("Failed to open console log file \"%s\"", console->log_path);
+               return -1;
+       }
+
+       DEBUG("Using \"%s\" as console log file", console->log_path);
+       return 0;
+}
+
 int lxc_console_create(struct lxc_conf *conf)
 {
        int ret, saved_errno;
@@ -698,16 +732,18 @@ int lxc_console_create(struct lxc_conf *conf)
                goto err;
        }
 
-       if (console->log_path) {
-               console->log_fd = lxc_unpriv(open(console->log_path, O_CLOEXEC | O_RDWR | O_CREAT | O_APPEND, 0600));
-               if (console->log_fd < 0) {
-                       SYSERROR("Failed to open console log file \"%s\"", console->log_path);
-                       goto err;
-               }
-               DEBUG("Using \"%s\" as console log file", console->log_path);
-       }
+       /* create console log file */
+       ret = lxc_console_create_log_file(console);
+       if (ret < 0)
+               goto err;
+
+       /* create console ringbuffer */
+       ret = lxc_console_create_ringbuf(console);
+       if (ret < 0)
+               goto err;
 
-       ret = lxc_setup_console_ringbuf(console);
+       /* create console ringbuffer log file */
+       ret = lxc_console_create_ringbuf_log_file(console);
        if (ret < 0)
                goto err;