>
> On 2022/9/22 17:32, zhangqilong wrote:
> >>
> >> On 2022/9/22 12:54, zhangqilong wrote:
> >>>> On 2022/9/22 10:07, zhangqilong wrote:
> >>>>>> On 2022/9/22 0:00, zhangqilong wrote:
> >>>>>>>> On 2022/9/21 21:57, zhangqilong wrote:
> >>>>>>>>>> On 2022/9/21 20:14, zhangqilong wrote:
> >>>>>>>>>>>> On 2022/9/21 15:57, Zhang Qilong wrote:
> >>>>>>>>>>>>> No-compressed file may suffer read performance issue
> due
> >> to
> >>>> it
> >>>>>>>>>>>>> can't use extent cache or the largest extent in inode
> >>>>>>>>>>>>> can't covered other parts of continuous blocks in
> readonly
> >> format
> >>>>>>>>>>>>> f2fs
> >>>>>>>> image.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Now it won't build extent cacge tree for no-compressed
> >>>>>>>>>>>>> file in readonly format f2fs image.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> For readonly format f2fs image, maybe the
> no-compressed
> >> file
> >>>>>>>> don't
> >>>>>>>>>>>>> have the largest extent, or it have more than one part
> >> which
> >>>>>>>>>>>>> have
> >>>>>>>>>>>>
> >>>>>>>>>>>> Why it can not have largest extent in f2fs_inode?
> >>>>>>>>>>>
> >>>>>>>>>>> The following several situations may occur:
> >>>>>>>>>>> 1) Wrote w/o the extent when the filesystem is
> read-write
> >>>> fs.
> >>>>>>>>>>>
> >>>>>>>>>>> 2) Largest extent have been drop after being
> >>>>>>>>>>> re-wrote, or it have
> >>>>>>>>>> been split to smaller parts.
> >>>>>>>>>>>
> >>>>>>>>>>> 3) The largest extent only covered one part of
> >>>>>>>>>>> continuous blocks,
> >>>>>>>>>> like:
> >>>>>>>>>>> |------parts 1(continuous blocks)-----|----not
> >>>>>>>>>> continuous---|---------------------parts 2 (continuous
> >>>>>>>>>> continuous---|blocks)-----------|---------|
> >>>>>>>>>>> The largest extent is part 2, but other parts
> >>>>>>>>>>> (like part1, ) can't be
> >>>>>>>>>> mapped in readonly format f2fs image which should have
> been
> >>>>>>>> mapped.
> >>>>>>>>>>
> >>>>>>>>>> largest extent of non-compressed file should be updated
> >> during
> >>>>>>>>>> sload in a ro f2fs image?
> >>>>>>>>>
> >>>>>>>>> Hi,
> >>>>>>>>>
> >>>>>>>>> I am sorry, I don't fully understand what you mean. I want to
> >>>>>>>>> show that the extent of file in readonly format f2fs image
> >>>>>>>>> could not existed or
> >>>>>>>> can't covered other parts that contain continuous blocks.
> >>>>>>>>
> >>>>>>>> Well, I mean the extent should be updated due to below flow?
> >>>> during
> >>>>>>>> the file was loaded into a formated f2fs image w/ ro feature.
> >>>>>>>>
> >>>>>>>> - f2fs_sload
> >>>>>>>> - build_directory
> >>>>>>>> - f2fs_build_file
> >>>>>>>>
> >>>>>>>> if (!c.compress.enabled || (c.feature &
> >>>>>>>> cpu_to_le32(F2FS_FEATURE_RO)))
> >>>>>>>> update_largest_extent(sbi, de->ino);
> >>>>>>>>
> >>>>>>>
> >>>>>>> Hi,
> >>>>>>>
> >>>>>>> I get it. I think we could consider this flow.
> >>>>>>> But it will change the metadata of the file, is it was a little
> >>>> inappropriate?
> >>>>>>> Maybe users does not want to do that during being loaded and
> >>>>>>> will
> >>>>>> refuse this change.
> >>>>>>
> >>>>>> I don't get it.
> >>>>>>
> >>>>>> IIUC, we can only load files into ro f2fs image w/ sload, and
> >>>>>> sload has updated largest extent for file, or am I missing
> something?
> >>>>>
> >>>>> Ah, maybe I misunderstood your idea just now. We could updated
> >>>> largest
> >>>>> extent for file when loading into ro f2fs image w/ sload, but it
> >>>>> will not solve situations 3) issue for the no-compressed file that
> >>>>> be
> >>>> mentioned previously.
> >>>>
> >>>> Why case 3) can happen? The data blocks should be allocated
> >>>> contiguously while sload loads file into image?
> >>>
> >>> That's what I thought before, it should allocated contiguously while
> >>> sload loads file into image. But I found that it may not be
> >>> completely continuous for the big file recently. It may contain
> >>> several discontinuous parts.
> >>
> >> I doubt it was caused by hot/cold data separation strategy, but I
> >> guess the strategy is not necessary for ro image, can you look into it?
> >
> > HI,
> >
> > "Looking into hot/cold data separation strategy" is a little difficult
> > for me now but I will continuous attention and research it in the future.
> > In addition, concurrent writing of multiple files also is likely to
> > cause this issue, so I think it is valueable sometimes :).
>
> How can we write files into ro image?
I means it is wrote when being sloaded to f2fs ro image.
Thanks,
>
> Thanks,
>
> >
> > Thanks,
> >
> >>
> >> Thanks,
> >>
> >>>
> >>> Thanks,
> >>>
> >>>>
> >>>> Thanks,
> >>>>
> >>>>>
> >>>>> Thanks,
> >>>>>
> >>>>>>
> >>>>>> Thanks,
> >>>>>>
> >>>>>>>
> >>>>>>> Thanks,
> >>>>>>>
> >>>>>>>> Thanks,
> >>>>>>>>
> >>>>>>>>> Whether it exists or not, we will not change or update largest
> >>>>>>>>> extent
> >>>>>>>> during sload in a ro f2fs image.
> >>>>>>>>>
> >>>>>>>>> Thanks,
> >>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> Thanks,
> >>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>> Thanks,
> >>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Thanks,
> >>>>>>>>>>>>
> >>>>>>>>>>>>> internally continuous blocks. So we add extent cache
> tree
> >>>>>>>>>>>>> for the no-compressed file in readonly format f2fs image.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> The cache policy is almost same with compressed file.
> The
> >>>>>>>>>>>>> difference is that, the no-compressed file part will set
> >>>>>>>>>>>>> min-number of continuous blocks
> F2FS_MIN_EXTENT_LEN
> >> in
> >>>>>> order
> >>>>>>>> to
> >>>>>>>>>>>>> reduce cache
> >>>>>>>>>> fragmentation.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Signed-off-by: Zhang Qilong
> <zhangqilo...@huawei.com>
> >>>>>>>>>>>>> ---
> >>>>>>>>>>>>> fs/f2fs/extent_cache.c | 52
> >>>>>>>>>>>> ++++++++++++++++++++++++++++++++++--------
> >>>>>>>>>>>>> 1 file changed, 42 insertions(+), 10 deletions(-)
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> diff --git a/fs/f2fs/extent_cache.c
> >>>>>>>>>>>>> b/fs/f2fs/extent_cache.c index
> >>>>>>>>>>>>> 387d53a61270..7e39381edca0 100644
> >>>>>>>>>>>>> --- a/fs/f2fs/extent_cache.c
> >>>>>>>>>>>>> +++ b/fs/f2fs/extent_cache.c
> >>>>>>>>>>>>> @@ -695,9 +695,12 @@ static void
> >>>>>>>>>>>> f2fs_update_extent_tree_range_compressed(struct
> inode
> >>>>>> *inode,
> >>>>>>>>>>>>> set_extent_info(&ei, fofs, blkaddr, llen);
> >>>>>>>>>>>>> ei.c_len = c_len;
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> - if (!__try_merge_extent_node(sbi, et, &ei, prev_en,
> >>>>>> next_en))
> >>>>>>>>>>>>> + if (!__try_merge_extent_node(sbi, et, &ei,
> prev_en,
> >>>>>> next_en)) {
> >>>>>>>>>>>>> + if (!c_len && llen < F2FS_MIN_EXTENT_LEN)
> >>>>>>>>>>>>> + goto unlock_out;
> >>>>>>>>>>>>> __insert_extent_tree(sbi, et, &ei,
> >>>>>>>>>>>>> insert_p, insert_parent,
> >> leftmost);
> >>>>>>>>>>>>> + }
> >>>>>>>>>>>>> unlock_out:
> >>>>>>>>>>>>> write_unlock(&et->lock);
> >>>>>>>>>>>>> }
> >>>>>>>>>>>>> @@ -726,24 +729,53 @@ static unsigned int
> >>>>>>>>>>>> f2fs_cluster_blocks_are_contiguous(struct
> dnode_of_data
> >>>> *dn)
> >>>>>>>>>>>>> return compressed ? i - 1 : i;
> >>>>>>>>>>>>> }
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> +/*
> >>>>>>>>>>>>> + * check whether normal file blocks are contiguous, and
> >> add
> >>>>>>>>>>>>> +extent cache
> >>>>>>>>>>>>> + * entry only if remained blocks are logically and
> >>>>>>>>>>>>> +physically
> >>>>>>>>>> contiguous.
> >>>>>>>>>>>>> + */
> >>>>>>>>>>>>> +static unsigned int
> >>>> f2fs_normal_blocks_are_contiguous(struct
> >>>>>>>>>>>>> +dnode_of_data *dn) {
> >>>>>>>>>>>>> + int i = 0;
> >>>>>>>>>>>>> + struct inode *inode = dn->inode;
> >>>>>>>>>>>>> + block_t first_blkaddr = data_blkaddr(inode,
> >> dn->node_page,
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> dn->ofs_in_node);
> >>>>>>>>>>>>> + unsigned int max_blocks =
> >>>>>> ADDRS_PER_PAGE(dn->node_page,
> >>>>>>>>>> inode)
> >>>>>>>>>>>>> + - dn->ofs_in_node;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + for (i = 1; i < max_blocks; i++) {
> >>>>>>>>>>>>> + block_t blkaddr = data_blkaddr(inode,
> >> dn->node_page,
> >>>>>>>>>>>>> + dn->ofs_in_node + i);
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + if (!__is_valid_data_blkaddr(blkaddr) ||
> >>>>>>>>>>>>> + first_blkaddr + i != blkaddr)
> >>>>>>>>>>>>> + return i;
> >>>>>>>>>>>>> + }
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + return i;
> >>>>>>>>>>>>> +}
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> void
> f2fs_readonly_update_extent_cache(struct
> >>>>>>>> dnode_of_data
> >>>>>>>>>> *dn,
> >>>>>>>>>>>>> pgoff_t index)
> >>>>>>>>>>>>> {
> >>>>>>>>>>>>> - unsigned int c_len =
> >>>>>> f2fs_cluster_blocks_are_contiguous(dn);
> >>>>>>>>>>>>> + unsigned int c_len = 0;
> >>>>>>>>>>>>> + unsigned int llen = 0;
> >>>>>>>>>>>>> block_t blkaddr;
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> - if (!c_len)
> >>>>>>>>>>>>> - return;
> >>>>>>>>>>>>> -
> >>>>>>>>>>>>> blkaddr = f2fs_data_blkaddr(dn);
> >>>>>>>>>>>>> - if (blkaddr == COMPRESS_ADDR)
> >>>>>>>>>>>>> - blkaddr = data_blkaddr(dn->inode,
> >> dn->node_page,
> >>>>>>>>>>>>> + if (f2fs_compressed_file(dn->inode)) {
> >>>>>>>>>>>>> + c_len =
> f2fs_cluster_blocks_are_contiguous(dn);
> >>>>>>>>>>>>> + if (!c_len)
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> + llen = F2FS_I(dn->inode)->i_cluster_size;
> >>>>>>>>>>>>> + if (blkaddr == COMPRESS_ADDR)
> >>>>>>>>>>>>> + blkaddr = data_blkaddr(dn->inode,
> >>>>>> dn->node_page,
> >>>>>>>>>>>>> dn->ofs_in_node
> >>>>>>>>>>>>> + 1);
> >>>>>>>>>>>>> + } else {
> >>>>>>>>>>>>> + llen =
> f2fs_normal_blocks_are_contiguous(dn);
> >>>>>>>>>>>>> + }
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>> f2fs_update_extent_tree_range_compressed(dn->inode,
> >>>>>>>>>>>>> - index, blkaddr,
> >>>>>>>>>>>>> -
> >>>>>>>>>>>>> F2FS_I(dn->inode)->i_cluster_size,
> >>>>>>>>>>>>> - c_len);
> >>>>>>>>>>>>> + index, blkaddr, llen, c_len);
> >>>>>>>>>>>>> }
> >>>>>>>>>>>>> #endif
> >>>>>>>>>>>>>
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