Re: [PATCH] f2fs: use round_up()/DIV_ROUND_UP()

From: Chao Yu
Date: Tue Mar 31 2020 - 03:51:38 EST


On 2020/3/31 11:55, Jaegeuk Kim wrote:
> On 03/31, Chao Yu wrote:
>> On 2020/3/31 2:42, Jaegeuk Kim wrote:
>>> On 03/30, Chao Yu wrote:
>>>> .i_cluster_size should be power of 2, so we can use round_up() instead
>>>> of roundup() to enhance the calculation.
>>>>
>>>> In addition, use DIV_ROUND_UP to clean up codes.
>>>>
>>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>>>> ---
>>>> fs/f2fs/data.c | 16 ++++++----------
>>>> fs/f2fs/file.c | 17 +++++------------
>>>> 2 files changed, 11 insertions(+), 22 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>>> index 0a829a89f596..8257d5e7aa3b 100644
>>>> --- a/fs/f2fs/data.c
>>>> +++ b/fs/f2fs/data.c
>>>> @@ -1969,8 +1969,6 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
>>>> bool is_readahead)
>>>> {
>>>> struct bio *bio = *bio_ret;
>>>> - const unsigned blkbits = inode->i_blkbits;
>>>> - const unsigned blocksize = 1 << blkbits;
>>>> sector_t block_in_file;
>>>> sector_t last_block;
>>>> sector_t last_block_in_file;
>>>> @@ -1979,8 +1977,8 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
>>>>
>>>> block_in_file = (sector_t)page_index(page);
>>>> last_block = block_in_file + nr_pages;
>>>> - last_block_in_file = (f2fs_readpage_limit(inode) + blocksize - 1) >>
>>>> - blkbits;
>>>> + last_block_in_file = DIV_ROUND_UP(f2fs_readpage_limit(inode),
>>>> + PAGE_SIZE);
>>>
>>> What if PAGE_SIZE is bigger than 4KB?
>>
>> We don't support 8kb+ sized-page, right?
>
> That's only assumption below. I don't think we can just replace block with PAGE
> in every places.

Fixed,

BTW, we didn't unify the usage of PAGE_SIZE/blocksize when
calling bio_add_page(), it needs to unify to use PAGE_SIZE?

f2fs_read_multi_pages()

if (bio_add_page(bio, page, blocksize, 0) < blocksize)

f2fs_submit_page_write

if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) < PAGE_SIZE) {

>
>>
>> static int __init init_f2fs_fs(void)
>> {
>> int err;
>>
>> if (PAGE_SIZE != F2FS_BLKSIZE) {
>> printk("F2FS not supported on PAGE_SIZE(%lu) != %d\n",
>> PAGE_SIZE, F2FS_BLKSIZE);
>> return -EINVAL;
>> }
>>
>> Thanks,
>>
>>>
>>>> if (last_block > last_block_in_file)
>>>> last_block = last_block_in_file;
>>>>
>>>> @@ -2062,7 +2060,7 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
>>>> */
>>>> f2fs_wait_on_block_writeback(inode, block_nr);
>>>>
>>>> - if (bio_add_page(bio, page, blocksize, 0) < blocksize)
>>>> + if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
>>>> goto submit_and_realloc;
>>>>
>>>> inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA);
>>>> @@ -2091,16 +2089,14 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>>> struct bio *bio = *bio_ret;
>>>> unsigned int start_idx = cc->cluster_idx << cc->log_cluster_size;
>>>> sector_t last_block_in_file;
>>>> - const unsigned blkbits = inode->i_blkbits;
>>>> - const unsigned blocksize = 1 << blkbits;
>>>> struct decompress_io_ctx *dic = NULL;
>>>> int i;
>>>> int ret = 0;
>>>>
>>>> f2fs_bug_on(sbi, f2fs_cluster_is_empty(cc));
>>>>
>>>> - last_block_in_file = (f2fs_readpage_limit(inode) +
>>>> - blocksize - 1) >> blkbits;
>>>> + last_block_in_file = DIV_ROUND_UP(f2fs_readpage_limit(inode),
>>>> + PAGE_SIZE);
>>>>
>>>> /* get rid of pages beyond EOF */
>>>> for (i = 0; i < cc->cluster_size; i++) {
>>>> @@ -2197,7 +2193,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>>>
>>>> f2fs_wait_on_block_writeback(inode, blkaddr);
>>>>
>>>> - if (bio_add_page(bio, page, blocksize, 0) < blocksize)
>>>> + if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
>>>> goto submit_and_realloc;
>>>>
>>>> inc_page_count(sbi, F2FS_RD_DATA);
>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>>> index c2d38a1c4972..0f8be076620c 100644
>>>> --- a/fs/f2fs/file.c
>>>> +++ b/fs/f2fs/file.c
>>>> @@ -736,16 +736,9 @@ int f2fs_truncate_blocks(struct inode *inode, u64 from, bool lock)
>>>> * for compressed file, only support cluster size
>>>> * aligned truncation.
>>>> */
>>>> - if (f2fs_compressed_file(inode)) {
>>>> - size_t cluster_shift = PAGE_SHIFT +
>>>> - F2FS_I(inode)->i_log_cluster_size;
>>>> - size_t cluster_mask = (1 << cluster_shift) - 1;
>>>> -
>>>> - free_from = from >> cluster_shift;
>>>> - if (from & cluster_mask)
>>>> - free_from++;
>>>> - free_from <<= cluster_shift;
>>>> - }
>>>> + if (f2fs_compressed_file(inode))
>>>> + free_from = round_up(from,
>>>> + F2FS_I(inode)->i_cluster_size << PAGE_SHIFT);
>>>> #endif
>>>>
>>>> err = f2fs_do_truncate_blocks(inode, free_from, lock);
>>>> @@ -3537,7 +3530,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
>>>>
>>>> end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
>>>> count = min(end_offset - dn.ofs_in_node, last_idx - page_idx);
>>>> - count = roundup(count, F2FS_I(inode)->i_cluster_size);
>>>> + count = round_up(count, F2FS_I(inode)->i_cluster_size);
>>>>
>>>> ret = release_compress_blocks(&dn, count);
>>>>
>>>> @@ -3689,7 +3682,7 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
>>>>
>>>> end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
>>>> count = min(end_offset - dn.ofs_in_node, last_idx - page_idx);
>>>> - count = roundup(count, F2FS_I(inode)->i_cluster_size);
>>>> + count = round_up(count, F2FS_I(inode)->i_cluster_size);
>>>>
>>>> ret = reserve_compress_blocks(&dn, count);
>>>>
>>>> --
>>>> 2.18.0.rc1
>>> .
>>>
> .
>