On Mon, Aug 09, 2021 at 08:12:26AM +0200, Christoph Hellwig wrote:
> Switch the page cache read functions to use iomap_iter instead of
> iomap_apply.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks reasonable,
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/iomap/buffered-io.c | 80 +++++++++++++++++++-----------------------
> 1 file changed, 37 insertions(+), 43 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 26e16cc9d44931..9cda461887afad 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -241,11 +241,12 @@ static inline bool iomap_block_needs_zeroing(struct inode *inode,
> pos >= i_size_read(inode);
> }
>
> -static loff_t
> -iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> - struct iomap *iomap, struct iomap *srcmap)
> +static loff_t iomap_readpage_iter(struct iomap_iter *iter,
> + struct iomap_readpage_ctx *ctx, loff_t offset)
> {
> - struct iomap_readpage_ctx *ctx = data;
> + struct iomap *iomap = &iter->iomap;
> + loff_t pos = iter->pos + offset;
> + loff_t length = iomap_length(iter) - offset;
> struct page *page = ctx->cur_page;
> struct iomap_page *iop;
> loff_t orig_pos = pos;
> @@ -253,15 +254,16 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> sector_t sector;
>
> if (iomap->type == IOMAP_INLINE)
> - return min(iomap_read_inline_data(inode, page, iomap), length);
> + return min(iomap_read_inline_data(iter->inode, page, iomap),
> + length);
>
> /* zero post-eof blocks as the page may be mapped */
> - iop = iomap_page_create(inode, page);
> - iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
> + iop = iomap_page_create(iter->inode, page);
> + iomap_adjust_read_range(iter->inode, iop, &pos, length, &poff, &plen);
> if (plen == 0)
> goto done;
>
> - if (iomap_block_needs_zeroing(inode, iomap, pos)) {
> + if (iomap_block_needs_zeroing(iter->inode, iomap, pos)) {
> zero_user(page, poff, plen);
> iomap_set_range_uptodate(page, poff, plen);
> goto done;
> @@ -313,23 +315,23 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> int
> iomap_readpage(struct page *page, const struct iomap_ops *ops)
> {
> - struct iomap_readpage_ctx ctx = { .cur_page = page };
> - struct inode *inode = page->mapping->host;
> - unsigned poff;
> - loff_t ret;
> + struct iomap_iter iter = {
> + .inode = page->mapping->host,
> + .pos = page_offset(page),
> + .len = PAGE_SIZE,
> + };
> + struct iomap_readpage_ctx ctx = {
> + .cur_page = page,
> + };
> + int ret;
>
> trace_iomap_readpage(page->mapping->host, 1);
>
> - for (poff = 0; poff < PAGE_SIZE; poff += ret) {
> - ret = iomap_apply(inode, page_offset(page) + poff,
> - PAGE_SIZE - poff, 0, ops, &ctx,
> - iomap_readpage_actor);
> - if (ret <= 0) {
> - WARN_ON_ONCE(ret == 0);
> - SetPageError(page);
> - break;
> - }
> - }
> + while ((ret = iomap_iter(&iter, ops)) > 0)
> + iter.processed = iomap_readpage_iter(&iter, &ctx, 0);
> +
> + if (ret < 0)
> + SetPageError(page);
>
> if (ctx.bio) {
> submit_bio(ctx.bio);
> @@ -348,15 +350,14 @@ iomap_readpage(struct page *page, const struct iomap_ops *ops)
> }
> EXPORT_SYMBOL_GPL(iomap_readpage);
>
> -static loff_t
> -iomap_readahead_actor(struct inode *inode, loff_t pos, loff_t length,
> - void *data, struct iomap *iomap, struct iomap *srcmap)
> +static loff_t iomap_readahead_iter(struct iomap_iter *iter,
> + struct iomap_readpage_ctx *ctx)
> {
> - struct iomap_readpage_ctx *ctx = data;
> + loff_t length = iomap_length(iter);
> loff_t done, ret;
>
> for (done = 0; done < length; done += ret) {
> - if (ctx->cur_page && offset_in_page(pos + done) == 0) {
> + if (ctx->cur_page && offset_in_page(iter->pos + done) == 0) {
> if (!ctx->cur_page_in_bio)
> unlock_page(ctx->cur_page);
> put_page(ctx->cur_page);
> @@ -366,8 +367,7 @@ iomap_readahead_actor(struct inode *inode, loff_t pos, loff_t length,
> ctx->cur_page = readahead_page(ctx->rac);
> ctx->cur_page_in_bio = false;
> }
> - ret = iomap_readpage_actor(inode, pos + done, length - done,
> - ctx, iomap, srcmap);
> + ret = iomap_readpage_iter(iter, ctx, done);
> }
>
> return done;
> @@ -390,25 +390,19 @@ iomap_readahead_actor(struct inode *inode, loff_t pos, loff_t length,
> */
> void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops)
> {
> - struct inode *inode = rac->mapping->host;
> - loff_t pos = readahead_pos(rac);
> - size_t length = readahead_length(rac);
> + struct iomap_iter iter = {
> + .inode = rac->mapping->host,
> + .pos = readahead_pos(rac),
> + .len = readahead_length(rac),
> + };
> struct iomap_readpage_ctx ctx = {
> .rac = rac,
> };
>
> - trace_iomap_readahead(inode, readahead_count(rac));
> + trace_iomap_readahead(rac->mapping->host, readahead_count(rac));
>
> - while (length > 0) {
> - ssize_t ret = iomap_apply(inode, pos, length, 0, ops,
> - &ctx, iomap_readahead_actor);
> - if (ret <= 0) {
> - WARN_ON_ONCE(ret == 0);
> - break;
> - }
> - pos += ret;
> - length -= ret;
> - }
> + while (iomap_iter(&iter, ops) > 0)
> + iter.processed = iomap_readahead_iter(&iter, &ctx);
>
> if (ctx.bio)
> submit_bio(ctx.bio);
> --
> 2.30.2
>
