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?
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);
>
