[PATCH v2 01/12] xfs: add a helper to figure out the space log reservation per item

[Jeff Liu]

On 01/19/2013 07:03 AM, Mark Tinguely wrote:
> On 01/10/13 07:47, Jeff Liu wrote:
>> Add a helper xfs_calc_buf_res() to calcuate out the space log reservations per item which were got
>> involved in a transaction.  It will call the xfs_buf_log_overhead() to figure out the extra space
>> for the struct xfs_buf_log_format that gets written into the log for every buffer as well as a little
>> bit of extra space because there also needs a log opheader, i.e. struct xlog_op_header.
>>
> The commit message is too wide.
> 
>> Signed-off-by: Jie Liu<jeff.liu at oracle.com>
>> ---
>>   fs/xfs/xfs_trans.c |   31 +++++++++++++++++++++++++++++++
>>   1 file changed, 31 insertions(+)
>>
>> diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
>> index 06ed520..6c601ea 100644
>> --- a/fs/xfs/xfs_trans.c
>> +++ b/fs/xfs/xfs_trans.c
>> @@ -37,14 +37,45 @@
>>   #include "xfs_extent_busy.h"
>>   #include "xfs_bmap.h"
>>   #include "xfs_quota.h"
>> +#include "xfs_qm.h"
>>   #include "xfs_trans_priv.h"
>>   #include "xfs_trans_space.h"
>>   #include "xfs_inode_item.h"
>> +#include "xfs_log_priv.h"
>> +#include "xfs_buf_item.h"
>>   #include "xfs_trace.h"
>>
>>   kmem_zone_t	*xfs_trans_zone;
>>   kmem_zone_t	*xfs_log_item_desc_zone;
>>
>> +/*
>> + * A buffer has a format structure overhead in the log in addition
>> + * to the data, so we need to take this into account when reserving
>> + * space in a transaction for a buffer.  Round the space required up
>> + * to a multiple of 128 bytes so that we don't change the historical
>> + * reservation that has been used for this overhead.
>> + */
>> +STATIC uint
>> +xfs_buf_log_overhead(void)
>> +{
>> +	return round_up(sizeof(struct xlog_op_header) +
>> +			sizeof(struct xfs_buf_log_format), 128);
>> +}
> 
> Not used directly except below. inline or fold below?
I should be inline.  Maybe it's proper to make xfs_calc_buf_res() inline
as well?

Thanks,
-Jeff