Messages in this thread | | | Date | Mon, 15 Oct 2012 16:47:51 +0800 | Subject | Re: [RFC v3 12/13] vfs: add debugfs support | From | Zhi Yong Wu <> |
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On Mon, Oct 15, 2012 at 4:04 PM, Dave Chinner <david@fromorbit.com> wrote: > On Wed, Oct 10, 2012 at 06:07:34PM +0800, zwu.kernel@gmail.com wrote: >> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> >> >> 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@linux.vnet.ibm.com> >> --- >> 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? It seems to be a good suggestion, let me try it. thanks.
> > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com
-- Regards,
Zhi Yong Wu
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