On Wed, Oct 10, 2012 at 06:07:34PM +0800, zwu.kernel@xxxxxxxxx wrote:
> From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
>
> Add a /sys/kernel/debug/hot_track/<device_name>/ directory for each
> volume that contains two files. The first, `inode_data', contains the
> heat information for inodes that have been brought into the hot data map
> structures. The second, `range_data', contains similar information for
> subfile ranges.
>
> Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
> ---
> fs/hot_tracking.c | 462 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/hot_tracking.h | 43 +++++
> 2 files changed, 505 insertions(+), 0 deletions(-)
.....
> +static int hot_debugfs_copy(struct debugfs_vol_data *data, char *msg, int len)
> +{
> + struct lstring *debugfs_log = data->debugfs_log;
> + uint new_log_alloc_size;
> + char *new_log;
> + static char err_msg[] = "No more memory!\n";
> +
> + if (len >= data->log_alloc_size - debugfs_log->len) {
......
> + }
> +
> + memcpy(debugfs_log->str + debugfs_log->len, data->log_work_buff, len);
> + debugfs_log->len += (unsigned long) len;
> +
> + return len;
> +}
> +
> +/* Returns the number of bytes written to the log. */
> +static int hot_debugfs_log(struct debugfs_vol_data *data, const char *fmt, ...)
> +{
> + struct lstring *debugfs_log = data->debugfs_log;
> + va_list args;
> + int len;
> + static char trunc_msg[] =
> + "The next message has been truncated.\n";
> +
> + if (debugfs_log->str == NULL)
> + return -1;
> +
> + spin_lock(&data->log_lock);
> +
> + va_start(args, fmt);
> + len = vsnprintf(data->log_work_buff,
> + sizeof(data->log_work_buff), fmt, args);
> + va_end(args);
> +
> + if (len >= sizeof(data->log_work_buff)) {
> + hot_debugfs_copy(data, trunc_msg, sizeof(trunc_msg));
> + }
> +
> + len = hot_debugfs_copy(data, data->log_work_buff, len);
> + spin_unlock(&data->log_lock);
> +
> + return len;
> +}
Aren't you just recreating seq_printf() here? i.e. can't you replace
all this complexity with generic seq_file/seq_operations constructs?
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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