Hi Jaegeuk,
On 2017/2/28 7:08, Jaegeuk Kim wrote:
> On 02/27, Yunlei He wrote:
>> This patch add a function to modify discard command if one segment
>> reuse before discard. Split this segment from multi-segments discard
>> range, and discard the left bigger range.
>
> Now MAX_DISCARD_BLOCKS() is set to section size, so there will be no
> multi-sections discard range. Am I missing some cases?
I think MAX_DISCARD_BLOCKS() just limit small discard and fstrim, f2fs
can still send multi-segments discard range if prefree segments is continuous.
Thanks.
>
> Thanks,
>
>>
>> Signed-off-by: Yunlei He <heyun...@huawei.com>
>> ---
>> fs/f2fs/segment.c | 18 +++++++++++++++++-
>> 1 file changed, 17 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>> index 9006d8e..5af736b 100644
>> --- a/fs/f2fs/segment.c
>> +++ b/fs/f2fs/segment.c
>> @@ -672,6 +672,22 @@ static void __remove_discard_cmd(struct f2fs_sb_info
>> *sbi, struct discard_cmd *d
>> kmem_cache_free(discard_cmd_slab, dc);
>> }
>>
>> +static void __modify_discard_cmd(struct f2fs_sb_info *sbi, struct
>> discard_cmd *dc, block_t blkaddr)
>> +{
>> + block_t end_block = START_BLOCK(sbi, GET_SEGNO(sbi, blkaddr) + 1);
>> +
>> + if (dc->lstart + dc->len <= end_block) {
>> + __remove_discard_cmd(sbi, dc);
>> + return;
>> + }
>> +
>> + if (dc->lstart - blkaddr < dc->lstart + dc->len - end_block) {
>> + dc->lstart = end_block;
>> + dc->len -= (end_block - dc->lstart);
>> + } else
>> + dc->len = blkaddr - dc->lstart;
>> +}
>> +
>> /* This should be covered by global mutex, &sit_i->sentry_lock */
>> void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
>> {
>> @@ -699,7 +715,7 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi,
>> block_t blkaddr)
>> if (dc->state == D_SUBMIT)
>> wait_for_completion_io(&dc->wait);
>> else
>> - __remove_discard_cmd(sbi, dc);
>> + __modify_discard_cmd(sbi, dc, blkaddr);
>> }
>> }
>> blk_finish_plug(&plug);
>> --
>> 2.10.1
>
> .
>
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, SlashDot.org! http://sdm.link/slashdot
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
