Re: [f2fs-dev] [PATCH 1/3] f2fs: support passing down write hints given by users to block layer
From: Hyunchul Lee
Date: Sun Jan 28 2018 - 20:49:39 EST
On 01/26/2018 11:10 AM, Chao Yu wrote:
> On 2018/1/26 7:46, Hyunchul Lee wrote:
>> On 01/25/2018 05:01 PM, Chao Yu wrote:
>>> Hi Hyunchul,
>>>
>>> On 2018/1/25 10:47, Hyunchul Lee wrote:
>>>> Hi Chao,
>>>>
>>>> On 01/25/2018 12:32 AM, Chao Yu wrote:
>>>>> On 2018/1/22 18:49, Hyunchul Lee wrote:
>>>>>> From: Hyunchul Lee <cheol.lee@xxxxxxx>
>>>>>>
>>>>>> Add the 'whint_mode' mount option that controls which write
>>>>>> hints are passed down to block layer. There are "off" and
>>>>>> "user-based" mode. The default mode is "off".
>>>>>>
>>>>>> 1) whint_mode=user-based. F2FS tries to pass down hints given
>>>>>> by users.
>>>>>
>>>>> Minor,
>>>>>
>>>>> 1) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET
>>>>>
>>>>> 2) whint_mode=user-based. F2FS tries to pass down hints given by users.
>>>>> ...
>>>>>
>>>>
>>>> Okay, I will reflect this.
>>>>
>>>>> How about changing all comments and codes with above order?
>>>>>
>>>>>>
>>>>>> User F2FS Block
>>>>>> ---- ---- -----
>>>>>> META WRITE_LIFE_NOT_SET
>>>>>> HOT_NODE "
>>>>>> WARM_NODE "
>>>>>> COLD_NODE "
>>>>>> ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
>>>>>> extension list " "
>>>>>>
>>>>>> -- buffered io
>>>>>> WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME
>>>>>> WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT
>>>>>> WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
>>>>>> WRITE_LIFE_NONE " "
>>>>>> WRITE_LIFE_MEDIUM " "
>>>>>> WRITE_LIFE_LONG " "
>>>>>>
>>>>>> -- direct io
>>>>>> WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME
>>>>>> WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT
>>>>>> WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
>>>>>> WRITE_LIFE_NONE " WRITE_LIFE_NONE
>>>>>> WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM
>>>>>> WRITE_LIFE_LONG " WRITE_LIFE_LONG
>>>>>>
>>>>>> 2) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET.
>>>>>>
>>>>>> Many thanks to Chao Yu and Jaegeuk Kim for comments to
>>>>>> implement this patch.
>>>>>>
>>>>>> Signed-off-by: Hyunchul Lee <cheol.lee@xxxxxxx>
>>>>>> ---
>>>>>> fs/f2fs/data.c | 27 ++++++++++++++++++++-----
>>>>>> fs/f2fs/f2fs.h | 9 +++++++++
>>>>>> fs/f2fs/segment.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>>>> fs/f2fs/super.c | 24 +++++++++++++++++++++-
>>>>>> 4 files changed, 113 insertions(+), 6 deletions(-)
>>>>>>
>>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>>>>> index 6cba74e..c76ddc2 100644
>>>>>> --- a/fs/f2fs/data.c
>>>>>> +++ b/fs/f2fs/data.c
>>>>>> @@ -175,15 +175,22 @@ static bool __same_bdev(struct f2fs_sb_info *sbi,
>>>>>> */
>>>>>> static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
>>>>>> struct writeback_control *wbc,
>>>>>> - int npages, bool is_read)
>>>>>> + int npages, bool is_read,
>>>>>> + enum page_type type, enum temp_type temp)
>>>>>> {
>>>>>> struct bio *bio;
>>>>>>
>>>>>> bio = f2fs_bio_alloc(sbi, npages, true);
>>>>>>
>>>>>> f2fs_target_device(sbi, blk_addr, bio);
>>>>>> - bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
>>>>>> - bio->bi_private = is_read ? NULL : sbi;
>>>>>> + if (is_read) {
>>>>>> + bio->bi_end_io = f2fs_read_end_io;
>>>>>> + bio->bi_private = NULL;
>>>>>> + } else {
>>>>>> + bio->bi_end_io = f2fs_write_end_io;
>>>>>> + bio->bi_private = sbi;
>>>>>> + bio->bi_write_hint = io_type_to_rw_hint(sbi, type, temp);
>>>>>> + }
>>>>>> if (wbc)
>>>>>> wbc_init_bio(wbc, bio);
>>>>>>
>>>>>> @@ -382,7 +389,7 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
>>>>>>
>>>>>> /* Allocate a new bio */
>>>>>> bio = __bio_alloc(fio->sbi, fio->new_blkaddr, fio->io_wbc,
>>>>>> - 1, is_read_io(fio->op));
>>>>>> + 1, is_read_io(fio->op), fio->type, fio->temp);
>>>>>>
>>>>>> if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
>>>>>> bio_put(bio);
>>>>>> @@ -445,7 +452,8 @@ int f2fs_submit_page_write(struct f2fs_io_info *fio)
>>>>>> goto out_fail;
>>>>>> }
>>>>>> io->bio = __bio_alloc(sbi, fio->new_blkaddr, fio->io_wbc,
>>>>>> - BIO_MAX_PAGES, false);
>>>>>> + BIO_MAX_PAGES, false,
>>>>>> + fio->type, fio->temp);
>>>>>> io->fio = *fio;
>>>>>> }
>>>>>>
>>>>>> @@ -2287,10 +2295,12 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>>>>>> {
>>>>>> struct address_space *mapping = iocb->ki_filp->f_mapping;
>>>>>> struct inode *inode = mapping->host;
>>>>>> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>>>>>> size_t count = iov_iter_count(iter);
>>>>>> loff_t offset = iocb->ki_pos;
>>>>>> int rw = iov_iter_rw(iter);
>>>>>> int err;
>>>>>> + enum rw_hint hint;
>>>>>>
>>>>>> err = check_direct_IO(inode, iter, offset);
>>>>>> if (err)
>>>>>> @@ -2301,11 +2311,18 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>>>>>>
>>>>>> trace_f2fs_direct_IO_enter(inode, offset, count, rw);
>>>>>>
>>>>>> + if (rw == WRITE && sbi->whint_mode == WHINT_MODE_OFF) {
>>>>>> + hint = iocb->ki_hint;
>>>>>> + iocb->ki_hint = WRITE_LIFE_NOT_SET;
>>>>>> + }
>>>>>
>>>>> In f2fs_preallocate_blocks, we should wrap original iocb->ki_hint with
>>>>> WRITE_LIFE_NOT_SET under WHINT_MODE_OFF mode?
>>>>>
>>>> In f2fs_preallocate_blocks, we should keep the original iocb->ki_hint to
>>>> select proper segments. So I think f2fs_direct_IO is the best place
>>>> before submiting io.
>>>
>>> Oh, right.
>>>
>>> How about using temporary variable to store sbi->whint_mode? so that we
>>> won't be affected by sbi->whint_mode changing.
>>>
>>
>> Yes, We need this.
>>
>>> And could you please check to make sure all .temp assignment being covered?
>>>
>>
>> I have checked all .temp assignments. But for read operations, this variable
>
> I've checked that too, there is nothing was missing.
>
> One more thing, our whint_mode is completely based on active six type logs,
> once some of them is close due to user configuration, write IO hint will be
> messed up, so what about just enabling WHINT_MODE_OFF mode if active log
> number is two or four?
>
Yes, I tought this is reasonable. write hints are not useful in two or four.
> And we need to adjust rw_hint_to_seg_type to be aware of active log number?
>
We does not have any choices in the two, But we can adjust the function
like the following in the four.
* in 4 active logs
F2FS
---------------------------------------
directory HOT_DATA
WRITE_LIFE_SHORT HOT_DATA
others COLD_DATA
>> is not used to determine write hints. so it is not initialized in this case.
>
> I think that's OK.
>
> Thanks,
>
>>
>> Thanks,
>>
>>> Thanks,
>>>
>>>>
>>>> Thanks,
>>>>
>>>>> Thanks,
>>>>>
>>>>>> +
>>>>>> down_read(&F2FS_I(inode)->dio_rwsem[rw]);
>>>>>> err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
>>>>>> up_read(&F2FS_I(inode)->dio_rwsem[rw]);
>>>>>>
>>>>>> if (rw == WRITE) {
>>>>>> + if (sbi->whint_mode == WHINT_MODE_OFF)
>>>>>> + iocb->ki_hint = hint;
>>>>>> if (err > 0) {
>>>>>> f2fs_update_iostat(F2FS_I_SB(inode), APP_DIRECT_IO,
>>>>>> err);
>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>>>>> index b7ba496..d7c2797 100644
>>>>>> --- a/fs/f2fs/f2fs.h
>>>>>> +++ b/fs/f2fs/f2fs.h
>>>>>> @@ -1035,6 +1035,11 @@ enum {
>>>>>> MAX_TIME,
>>>>>> };
>>>>>>
>>>>>> +enum {
>>>>>> + WHINT_MODE_OFF, /* not pass down write hints */
>>>>>> + WHINT_MODE_USER, /* try to pass down hints given by users */
>>>>>> +};
>>>>>> +
>>>>>> struct f2fs_sb_info {
>>>>>> struct super_block *sb; /* pointer to VFS super block */
>>>>>> struct proc_dir_entry *s_proc; /* proc entry */
>>>>>> @@ -1218,6 +1223,8 @@ struct f2fs_sb_info {
>>>>>> char *s_qf_names[MAXQUOTAS];
>>>>>> int s_jquota_fmt; /* Format of quota to use */
>>>>>> #endif
>>>>>> + /* For which write hints are passed down to block layer */
>>>>>> + int whint_mode;
>>>>>> };
>>>>>>
>>>>>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>>>>>> @@ -2766,6 +2773,8 @@ int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
>>>>>> int __init create_segment_manager_caches(void);
>>>>>> void destroy_segment_manager_caches(void);
>>>>>> int rw_hint_to_seg_type(enum rw_hint hint);
>>>>>> +enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi, enum page_type type,
>>>>>> + enum temp_type temp);
>>>>>>
>>>>>> /*
>>>>>> * checkpoint.c
>>>>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>>>>> index e5739ce..8bc1fc1 100644
>>>>>> --- a/fs/f2fs/segment.c
>>>>>> +++ b/fs/f2fs/segment.c
>>>>>> @@ -2458,6 +2458,62 @@ int rw_hint_to_seg_type(enum rw_hint hint)
>>>>>> }
>>>>>> }
>>>>>>
>>>>>> +/* This returns write hints for each segment type. This hints will be
>>>>>> + * passed down to block layer. There are 2 mapping tables which depend on
>>>>>> + * the mount option 'whint'.
>>>>>> + *
>>>>>> + * 1) whint_mode=user-based. F2FS tries to pass down hints given by users.
>>>>>> + *
>>>>>> + * User F2FS Block
>>>>>> + * ---- ---- -----
>>>>>> + * META WRITE_LIFE_NOT_SET
>>>>>> + * HOT_NODE "
>>>>>> + * WARM_NODE "
>>>>>> + * COLD_NODE "
>>>>>> + * ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
>>>>>> + * extension list " "
>>>>>> + *
>>>>>> + * -- buffered io
>>>>>> + * WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME
>>>>>> + * WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT
>>>>>> + * WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
>>>>>> + * WRITE_LIFE_NONE " "
>>>>>> + * WRITE_LIFE_MEDIUM " "
>>>>>> + * WRITE_LIFE_LONG " "
>>>>>> + *
>>>>>> + * -- direct io
>>>>>> + * WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME
>>>>>> + * WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT
>>>>>> + * WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
>>>>>> + * WRITE_LIFE_NONE " WRITE_LIFE_NONE
>>>>>> + * WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM
>>>>>> + * WRITE_LIFE_LONG " WRITE_LIFE_LONG
>>>>>> + *
>>>>>> + * 2) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET.
>>>>>> + *
>>>>>> + */
>>>>>> +
>>>>>> +enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi,
>>>>>> + enum page_type type, enum temp_type temp)
>>>>>> +{
>>>>>> + if (sbi->whint_mode == WHINT_MODE_USER) {
>>>>>> + if (type == DATA) {
>>>>>> + switch (temp) {
>>>>>> + case COLD:
>>>>>> + return WRITE_LIFE_EXTREME;
>>>>>> + case HOT:
>>>>>> + return WRITE_LIFE_SHORT;
>>>>>> + default:
>>>>>> + return WRITE_LIFE_NOT_SET;
>>>>>> + }
>>>>>> + } else {
>>>>>> + return WRITE_LIFE_NOT_SET;
>>>>>> + }
>>>>>> + } else {
>>>>>> + return WRITE_LIFE_NOT_SET;
>>>>>> + }
>>>>>> +}
>>>>>> +
>>>>>> static int __get_segment_type_2(struct f2fs_io_info *fio)
>>>>>> {
>>>>>> if (fio->type == DATA)
>>>>>> @@ -2645,6 +2701,7 @@ void write_meta_page(struct f2fs_sb_info *sbi, struct page *page,
>>>>>> struct f2fs_io_info fio = {
>>>>>> .sbi = sbi,
>>>>>> .type = META,
>>>>>> + .temp = HOT,
>>>>>
>>>>> Could you check to make sure all .temp being covered?
>>>>>
>>>>>> .op = REQ_OP_WRITE,
>>>>>> .op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
>>>>>> .old_blkaddr = page->index,
>>>>>> @@ -2693,6 +2750,8 @@ int rewrite_data_page(struct f2fs_io_info *fio)
>>>>>> int err;
>>>>>>
>>>>>> fio->new_blkaddr = fio->old_blkaddr;
>>>>>> + /* i/o temperature is needed for passing down write hints */
>>>>>> + __get_segment_type(fio);
>>>>>> stat_inc_inplace_blocks(fio->sbi);
>>>>>>
>>>>>> err = f2fs_submit_page_bio(fio);
>>>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>>>> index 8173ae6..9e22926 100644
>>>>>> --- a/fs/f2fs/super.c
>>>>>> +++ b/fs/f2fs/super.c
>>>>>> @@ -129,6 +129,7 @@ enum {
>>>>>> Opt_jqfmt_vfsold,
>>>>>> Opt_jqfmt_vfsv0,
>>>>>> Opt_jqfmt_vfsv1,
>>>>>> + Opt_whint,
>>>>>> Opt_err,
>>>>>> };
>>>>>>
>>>>>> @@ -182,6 +183,7 @@ enum {
>>>>>> {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
>>>>>> {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
>>>>>> {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
>>>>>> + {Opt_whint, "whint_mode=%s"},
>>>>>> {Opt_err, NULL},
>>>>>> };
>>>>>>
>>>>>> @@ -679,6 +681,22 @@ static int parse_options(struct super_block *sb, char *options)
>>>>>> "quota operations not supported");
>>>>>> break;
>>>>>> #endif
>>>>>> + case Opt_whint:
>>>>>> + name = match_strdup(&args[0]);
>>>>>> + if (!name)
>>>>>> + return -ENOMEM;
>>>>>> + if (strlen(name) == 10 &&
>>>>>> + !strncmp(name, "user-based", 10)) {
>>>>>> + sbi->whint_mode = WHINT_MODE_USER;
>>>>>> + } else if (strlen(name) == 3 &&
>>>>>> + !strncmp(name, "off", 3)) {
>>>>>> + sbi->whint_mode = WHINT_MODE_OFF;
>>>>>> + } else {
>>>>>> + kfree(name);
>>>>>> + return -EINVAL;
>>>>>> + }
>>>>>> + kfree(name);
>>>>>> + break;
>>>>>> default:
>>>>>> f2fs_msg(sb, KERN_ERR,
>>>>>> "Unrecognized mount option \"%s\" or missing value",
>>>>>> @@ -1225,6 +1243,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
>>>>>> seq_puts(seq, ",prjquota");
>>>>>> #endif
>>>>>> f2fs_show_quota_options(seq, sbi->sb);
>>>>>> + if (sbi->whint_mode == WHINT_MODE_USER)
>>>>>> + seq_printf(seq, ",whint_mode=%s", "user-based");
>>>>>>
>>>>>> return 0;
>>>>>> }
>>>>>> @@ -1234,6 +1254,7 @@ static void default_options(struct f2fs_sb_info *sbi)
>>>>>> /* init some FS parameters */
>>>>>> sbi->active_logs = NR_CURSEG_TYPE;
>>>>>> sbi->inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
>>>>>> + sbi->whint_mode = WHINT_MODE_OFF;
>>>>>>
>>>>>> set_opt(sbi, BG_GC);
>>>>>> set_opt(sbi, INLINE_XATTR);
>>>>>> @@ -1274,6 +1295,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>>>>>> bool need_restart_gc = false;
>>>>>> bool need_stop_gc = false;
>>>>>> bool no_extent_cache = !test_opt(sbi, EXTENT_CACHE);
>>>>>> + int old_whint_mode = sbi->whint_mode;
>>>>>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>>>>>> struct f2fs_fault_info ffi = sbi->fault_info;
>>>>>> #endif
>>>>>> @@ -1373,7 +1395,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>>>>>> need_stop_gc = true;
>>>>>> }
>>>>>>
>>>>>> - if (*flags & SB_RDONLY) {
>>>>>> + if (*flags & SB_RDONLY || sbi->whint_mode != old_whint_mode) {
>>>>>> writeback_inodes_sb(sb, WB_REASON_SYNC);
>>>>>> sync_inodes_sb(sb);
>>>>>>
>>>>>>
>>>>>
>>>>
>>>> .
>>>>
>>>
>>>
>>
>> .
>>
>
>