Re: [RFC PATCH v5] f2fs: support data compression

From: Chao Yu
Date: Mon Dec 30 2019 - 20:46:01 EST


On 2019/12/31 8:46, Jaegeuk Kim wrote:
> On 12/23, Chao Yu wrote:
>> Hi Jaegeuk,
>>
>> Sorry for the delay.
>>
>> On 2019/12/19 5:46, Jaegeuk Kim wrote:
>>> Hi Chao,
>>>
>>> I still see some diffs from my latest testing version, so please check anything
>>> that you made additionally from here.
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev&id=25d18e19a91e60837d36368ee939db13fd16dc64
>>
>> I've checked the diff and picked up valid parts, could you please check and
>> comment on it?
>>
>> ---
>> fs/f2fs/compress.c | 8 ++++----
>> fs/f2fs/data.c | 18 +++++++++++++++---
>> fs/f2fs/f2fs.h | 3 +++
>> fs/f2fs/file.c | 1 -
>> 4 files changed, 22 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
>> index af23ed6deffd..1bc86a54ad71 100644
>> --- a/fs/f2fs/compress.c
>> +++ b/fs/f2fs/compress.c
>> @@ -593,7 +593,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
>> fgp_flag, GFP_NOFS);
>> if (!page) {
>> ret = -ENOMEM;
>> - goto unlock_pages;
>> + goto release_pages;
>> }
>>
>> if (PageUptodate(page))
>> @@ -608,13 +608,13 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
>> ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
>> &last_block_in_bio, false);
>> if (ret)
>> - goto release_pages;
>> + goto unlock_pages;
>> if (bio)
>> f2fs_submit_bio(sbi, bio, DATA);
>>
>> ret = f2fs_init_compress_ctx(cc);
>> if (ret)
>> - goto release_pages;
>> + goto unlock_pages;
>> }
>>
>> for (i = 0; i < cc->cluster_size; i++) {
>> @@ -762,7 +762,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
>> if (err)
>> goto out_unlock_op;
>>
>> - psize = (cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
>> + psize = (loff_t)(cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
>>
>> err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
>> if (err)
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index 19cd03450066..f1f5c701228d 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -184,13 +184,18 @@ static void f2fs_decompress_work(struct bio_post_read_ctx *ctx)
>> }
>>
>> #ifdef CONFIG_F2FS_FS_COMPRESSION
>> +void f2fs_verify_pages(struct page **rpages, unsigned int cluster_size)
>> +{
>> + f2fs_decompress_end_io(rpages, cluster_size, false, true);
>> +}
>> +
>> static void f2fs_verify_bio(struct bio *bio)
>> {
>> struct page *page = bio_first_page_all(bio);
>> struct decompress_io_ctx *dic =
>> (struct decompress_io_ctx *)page_private(page);
>>
>> - f2fs_decompress_end_io(dic->rpages, dic->cluster_size, false, true);
>> + f2fs_verify_pages(dic->rpages, dic->cluster_size);
>> f2fs_free_dic(dic);
>> }
>> #endif
>> @@ -507,10 +512,16 @@ static bool __has_merged_page(struct bio *bio, struct inode *inode,
>> bio_for_each_segment_all(bvec, bio, iter_all) {
>> struct page *target = bvec->bv_page;
>>
>> - if (fscrypt_is_bounce_page(target))
>> + if (fscrypt_is_bounce_page(target)) {
>> target = fscrypt_pagecache_page(target);
>> - if (f2fs_is_compressed_page(target))
>> + if (IS_ERR(target))
>> + continue;
>> + }
>> + if (f2fs_is_compressed_page(target)) {
>> target = f2fs_compress_control_page(target);
>> + if (IS_ERR(target))
>> + continue;
>> + }
>>
>> if (inode && inode == target->mapping->host)
>> return true;
>> @@ -2039,6 +2050,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>> if (ret)
>> goto out;
>>
>> + /* cluster was overwritten as normal cluster */
>> if (dn.data_blkaddr != COMPRESS_ADDR)
>> goto out;
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 5d55cef66410..17d2af4eeafb 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -2719,6 +2719,7 @@ static inline void set_compress_context(struct inode *inode)
>> 1 << F2FS_I(inode)->i_log_cluster_size;
>> F2FS_I(inode)->i_flags |= F2FS_COMPR_FL;
>> set_inode_flag(inode, FI_COMPRESSED_FILE);
>> + stat_inc_compr_inode(inode);
>> }
>>
>> static inline unsigned int addrs_per_inode(struct inode *inode)
>> @@ -3961,6 +3962,8 @@ static inline bool f2fs_force_buffered_io(struct inode *inode,
>> return true;
>> if (f2fs_is_multi_device(sbi))
>> return true;
>> + if (f2fs_compressed_file(inode))
>> + return true;
>> /*
>> * for blkzoned device, fallback direct IO to buffered IO, so
>> * all IOs can be serialized by log-structured write.
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index bde5612f37f5..9aeadf14413c 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -1828,7 +1828,6 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
>> return -EINVAL;
>>
>> set_compress_context(inode);
>> - stat_inc_compr_inode(inode);
>
> As this breaks the count, I'll keep as is.

@@ -2719,6 +2719,7 @@ static inline void set_compress_context(struct inode *inode)
1 << F2FS_I(inode)->i_log_cluster_size;
F2FS_I(inode)->i_flags |= F2FS_COMPR_FL;
set_inode_flag(inode, FI_COMPRESSED_FILE);
+ stat_inc_compr_inode(inode);

If I'm not missing anything, stat_inc_compr_inode() should be called inside
set_compress_context() in where we convert normal inode to compress one,
right?

Thanks,

>
> Thanks,
>
>> }
>> }
>> if ((iflags ^ fi->i_flags) & F2FS_NOCOMP_FL) {
>> --
>> 2.18.0.rc1
>>
>> Thanks,
> .
>