On 2019/7/12 19:54, Andreas Gruenbacher wrote:
> On Fri, 12 Jul 2019 at 11:31, Chao Yu <yuchao0@xxxxxxxxxx> wrote:
>> On 2019/7/11 20:28, Andreas Gruenbacher wrote:
>>> Something along the lines of the attached, broken patch might work in
>>> the end.
>>>
>>> Andreas
>>>
>>> ---
>>> fs/buffer.c | 10 ++++--
>>> fs/iomap.c | 74 +++++++++++++++++++++++++++++--------------
>>> include/linux/iomap.h | 3 ++
>>> 3 files changed, 61 insertions(+), 26 deletions(-)
>>>
>>> diff --git a/fs/buffer.c b/fs/buffer.c
>>> index e450c55f6434..8d8668e377ab 100644
>>> --- a/fs/buffer.c
>>> +++ b/fs/buffer.c
>>> @@ -1873,8 +1873,8 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
>>> EXPORT_SYMBOL(page_zero_new_buffers);
>>>
>>> static void
>>> -iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh,
>>> - struct iomap *iomap)
>>> +iomap_to_bh(struct inode *inode, struct page *page, sector_t block,
>>> + struct buffer_head *bh, struct iomap *iomap)
>>> {
>>> loff_t offset = block << inode->i_blkbits;
>>>
>>> @@ -1924,6 +1924,10 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh,
>>> inode->i_blkbits;
>>> set_buffer_mapped(bh);
>>> break;
>>> + case IOMAP_INLINE:
>>> + __iomap_read_inline_data(inode, page, iomap);
>>> + set_buffer_uptodate(bh);
>>> + break;
>>> }
>>> }
>>>
>>> @@ -1969,7 +1973,7 @@ int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
>>> if (err)
>>> break;
>>> } else {
>>> - iomap_to_bh(inode, block, bh, iomap);
>>> + iomap_to_bh(inode, page, block, bh, iomap);
>>> }
>>>
>>> if (buffer_new(bh)) {
>>> diff --git a/fs/iomap.c b/fs/iomap.c
>>> index 45aa58e837b5..61188e95def2 100644
>>> --- a/fs/iomap.c
>>> +++ b/fs/iomap.c
>>> @@ -260,24 +260,47 @@ struct iomap_readpage_ctx {
>>> struct list_head *pages;
>>> };
>>>
>>> -static void
>>> -iomap_read_inline_data(struct inode *inode, struct page *page,
>>> +#define offset_in_block(offset, inode) \
>>> + ((unsigned long)(offset) & (i_blocksize(inode) - 1))
>>> +
>>> +static bool
>>> +inline_data_within_block(struct inode *inode, struct iomap *iomap,
>>> + unsigned int size)
>>> +{
>>> + unsigned int off = offset_in_block(iomap->inline_data, inode);
>>> +
>>> + return size <= i_blocksize(inode) - off;
>>> +}
>>> +
>>> +void
>>> +__iomap_read_inline_data(struct inode *inode, struct page *page,
>>> struct iomap *iomap)
>>> {
>>> - size_t size = i_size_read(inode);
>>> + size_t size = offset_in_block(i_size_read(inode), inode);
>>> + unsigned int poff = offset_in_page(iomap->offset);
>>> + unsigned int bsize = i_blocksize(inode);
>>> void *addr;
>>>
>>> if (PageUptodate(page))
>>> return;
>>>
>>> - BUG_ON(page->index);
>>> - BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data));
>>> + BUG_ON(!inline_data_within_block(inode, iomap, size));
>>>
>>> addr = kmap_atomic(page);
>>> - memcpy(addr, iomap->inline_data, size);
>>> - memset(addr + size, 0, PAGE_SIZE - size);
>>> + memcpy(addr + poff, iomap->inline_data, size);
>>> + memset(addr + poff + size, 0, bsize - size);
>>> kunmap_atomic(addr);
>>> - SetPageUptodate(page);
>>> +}
>>> +
>>> +static void
>>> +iomap_read_inline_data(struct inode *inode, struct page *page,
>>> + struct iomap *iomap)
>>> +{
>>> + unsigned int poff = offset_in_page(iomap->offset);
>>> + unsigned int bsize = i_blocksize(inode);
>>> +
>>> + __iomap_read_inline_data(inode, page, iomap);
>>> + iomap_set_range_uptodate(page, poff, bsize);
>>> }
>>>
>>> static loff_t
>>> @@ -292,11 +315,8 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
>>> unsigned poff, plen;
>>> sector_t sector;
>>>
>>> - if (iomap->type == IOMAP_INLINE) {
>>> - WARN_ON_ONCE(pos);
>>> + if (iomap->type == IOMAP_INLINE)
>>> iomap_read_inline_data(inode, page, iomap);
>>> - return PAGE_SIZE;
>>
>> Hi Andreas,
>>
>> Thanks for your patch.
>>
>> In my erofs test case, filled inline data will be zeroed out due to we fallback
>> to following flow:
>>
>> if (iomap->type != IOMAP_MAPPED || pos >= i_size_read(inode)) {
>> zero_user(page, poff, plen);
>>
>> Should we return before this condition check?
>
> Yes, probably by returning i_blocksize(inode) after
> iomap_read_inline_data, but that alone isn't enough to make the patch
Could you please resend this diff as a new patch with above fix?
> work completely. This really needs a review from Christoph and careful
> testing of all the code paths.
Later, I can do the test on read path.
Thanks,
>
> Andreas
>
>> Thanks,
>>
>>> - }
>>>
>>> /* zero post-eof blocks as the page may be mapped */
>>> iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
>>> @@ -637,6 +657,11 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
>>> if (PageUptodate(page))
>>> return 0;
>>>
>>> + if (iomap->type == IOMAP_INLINE) {
>>> + iomap_read_inline_data(inode, page, iomap);
>>> + return 0;
>>> + }
>>> +
>>> do {
>>> iomap_adjust_read_range(inode, iop, &block_start,
>>> block_end - block_start, &poff, &plen);
>>> @@ -682,9 +707,7 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
>>> goto out_no_page;
>>> }
>>>
>>> - if (iomap->type == IOMAP_INLINE)
>>> - iomap_read_inline_data(inode, page, iomap);
>>> - else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
>>> + if (iomap->flags & IOMAP_F_BUFFER_HEAD)
>>> status = __block_write_begin_int(page, pos, len, NULL, iomap);
>>> else
>>> status = __iomap_write_begin(inode, pos, len, page, iomap);
>>> @@ -761,11 +784,11 @@ iomap_write_end_inline(struct inode *inode, struct page *page,
>>> {
>>> void *addr;
>>>
>>> - WARN_ON_ONCE(!PageUptodate(page));
>>> - BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data));
>>> + BUG_ON(!inline_data_within_block(inode, iomap, pos + copied));
>>>
>>> addr = kmap_atomic(page);
>>> - memcpy(iomap->inline_data + pos, addr + pos, copied);
>>> + memcpy(iomap->inline_data + offset_in_block(pos, inode),
>>> + addr + offset_in_page(pos), copied);
>>> kunmap_atomic(addr);
>>>
>>> mark_inode_dirty(inode);
>>> @@ -1064,7 +1087,7 @@ iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
>>> const struct iomap_ops *ops)
>>> {
>>> unsigned int blocksize = i_blocksize(inode);
>>> - unsigned int off = pos & (blocksize - 1);
>>> + unsigned int off = offset_in_block(pos, inode);
>>>
>>> /* Block boundary? Nothing to do */
>>> if (!off)
>>> @@ -1772,21 +1795,26 @@ iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length,
>>> struct iov_iter *iter = dio->submit.iter;
>>> size_t copied;
>>>
>>> - BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data));
>>> + BUG_ON(!inline_data_within_block(inode, iomap, pos + length));
>>>
>>> if (dio->flags & IOMAP_DIO_WRITE) {
>>> loff_t size = inode->i_size;
>>>
>>> if (pos > size)
>>> - memset(iomap->inline_data + size, 0, pos - size);
>>> - copied = copy_from_iter(iomap->inline_data + pos, length, iter);
>>> + memset(iomap->inline_data +
>>> + offset_in_block(size, inode), 0, pos - size);
>>> + copied = copy_from_iter(iomap->inline_data +
>>> + offset_in_block(pos, inode),
>>> + length, iter);
>>> if (copied) {
>>> if (pos + copied > size)
>>> i_size_write(inode, pos + copied);
>>> mark_inode_dirty(inode);
>>> }
>>> } else {
>>> - copied = copy_to_iter(iomap->inline_data + pos, length, iter);
>>> + copied = copy_to_iter(iomap->inline_data +
>>> + offset_in_block(pos, inode),
>>> + length, iter);
>>> }
>>> dio->size += copied;
>>> return copied;
>>> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
>>> index 2103b94cb1bf..a8a60dd2fdc0 100644
>>> --- a/include/linux/iomap.h
>>> +++ b/include/linux/iomap.h
>>> @@ -131,6 +131,9 @@ static inline struct iomap_page *to_iomap_page(struct page *page)
>>> return NULL;
>>> }
>>>
>>> +void __iomap_read_inline_data(struct inode *inode, struct page *page,
>>> + struct iomap *iomap);
>>> +
>>> ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
>>> const struct iomap_ops *ops);
>>> int iomap_readpage(struct page *page, const struct iomap_ops *ops);
>>>
> .
>
