A synchronous readpage lets us report the actual errno instead of ineffectively setting PageError.
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> --- fs/iomap/buffered-io.c | 74 ++++++++++++++++++++++++------------------ 1 file changed, 42 insertions(+), 32 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index e60f572e1590..887bf871ca9b 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -150,9 +150,6 @@ static void iomap_set_range_uptodate(struct page *page, unsigned off, unsigned last = (off + len - 1) >> inode->i_blkbits; unsigned long flags; - if (PageError(page)) - return; - if (!iop) { SetPageUptodate(page); return; @@ -165,42 +162,50 @@ static void iomap_set_range_uptodate(struct page *page, unsigned off, spin_unlock_irqrestore(&iop->uptodate_lock, flags); } -static void -iomap_read_page_end_io(struct bio_vec *bvec, int error) +static void iomap_read_page_end_io(struct bio_vec *bvec, + struct completion *done, bool error) { struct page *page = bvec->bv_page; struct iomap_page *iop = to_iomap_page(page); - if (unlikely(error)) { - ClearPageUptodate(page); - SetPageError(page); - } else { + if (!error) iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len); - } - if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending)) - unlock_page(page); + if (!iop || + atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending)) { + if (done) + complete(done); + else + unlock_page(page); + } } +struct iomap_readpage_ctx { + struct page *cur_page; + bool cur_page_in_bio; + blk_status_t status; + struct bio *bio; + struct readahead_control *rac; + struct completion done; +}; + static void iomap_read_end_io(struct bio *bio) { - int error = blk_status_to_errno(bio->bi_status); + struct iomap_readpage_ctx *ctx = bio->bi_private; struct bio_vec *bvec; struct bvec_iter_all iter_all; + /* Capture the first error */ + if (ctx && ctx->status == BLK_STS_OK) + ctx->status = bio->bi_status; + bio_for_each_segment_all(bvec, bio, iter_all) - iomap_read_page_end_io(bvec, error); + iomap_read_page_end_io(bvec, ctx ? &ctx->done : NULL, + bio->bi_status != BLK_STS_OK); bio_put(bio); } -struct iomap_readpage_ctx { - struct page *cur_page; - bool cur_page_in_bio; - struct bio *bio; - struct readahead_control *rac; -}; - static void iomap_read_inline_data(struct inode *inode, struct page *page, struct iomap *iomap) @@ -292,6 +297,8 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, ctx->bio->bi_opf = REQ_OP_READ; if (ctx->rac) ctx->bio->bi_opf |= REQ_RAHEAD; + else + ctx->bio->bi_private = ctx; ctx->bio->bi_iter.bi_sector = sector; bio_set_dev(ctx->bio, iomap->bdev); ctx->bio->bi_end_io = iomap_read_end_io; @@ -318,15 +325,17 @@ iomap_readpage(struct page *page, const struct iomap_ops *ops) trace_iomap_readpage(page->mapping->host, 1); + ctx.status = BLK_STS_OK; + init_completion(&ctx.done); + 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); + if (WARN_ON_ONCE(ret == 0)) + ret = -EIO; + if (ret < 0) break; - } } if (ctx.bio) { @@ -334,15 +343,16 @@ iomap_readpage(struct page *page, const struct iomap_ops *ops) WARN_ON_ONCE(!ctx.cur_page_in_bio); } else { WARN_ON_ONCE(ctx.cur_page_in_bio); - unlock_page(page); + complete(&ctx.done); } - /* - * Just like mpage_readahead and block_read_full_page we always - * return 0 and just mark the page as PageError on errors. This - * should be cleaned up all through the stack eventually. - */ - return 0; + wait_for_completion(&ctx.done); + if (ret >= 0) + ret = blk_status_to_errno(ctx.status); + if (ret == 0) + return AOP_UPDATED_PAGE; + unlock_page(page); + return ret; } EXPORT_SYMBOL_GPL(iomap_readpage); -- 2.28.0
