>From e58c52e69a9aef07c0089f9ce552fca96d42bce9 Mon Sep 17 00:00:00 2001 Message-Id: From: Omar Sandoval Date: Tue, 18 Nov 2014 22:42:10 -0800 Subject: [PATCH] swap: use direct_IO for swap_readpage Signed-off-by: Omar Sandoval --- fs/direct-io.c | 8 +++++--- mm/page_io.c | 37 ++++++++++++++++++++++++++++++------- 2 files changed, 35 insertions(+), 10 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index e181b6b..e542ce4 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -120,6 +120,7 @@ struct dio { spinlock_t bio_lock; /* protects BIO fields below */ int page_errors; /* errno from get_user_pages() */ int is_async; /* is IO async ? */ + int should_dirty; /* should we mark read pages dirty? */ bool defer_completion; /* defer AIO completion to workqueue? */ int io_error; /* IO error in completion path */ unsigned long refcount; /* direct_io_worker() and bios */ @@ -392,7 +393,7 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio) dio->refcount++; spin_unlock_irqrestore(&dio->bio_lock, flags); - if (dio->is_async && dio->rw == READ) + if (dio->is_async && dio->rw == READ && dio->should_dirty) bio_set_pages_dirty(bio); if (sdio->submit_io) @@ -463,13 +464,13 @@ static int dio_bio_complete(struct dio *dio, struct bio *bio) if (!uptodate) dio->io_error = -EIO; - if (dio->is_async && dio->rw == READ) { + if (dio->is_async && dio->rw == READ && dio->should_dirty) { bio_check_pages_dirty(bio); /* transfers ownership */ } else { bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; - if (dio->rw == READ && !PageCompound(page)) + if (dio->rw == READ && !PageCompound(page) && dio->should_dirty) set_page_dirty_lock(page); page_cache_release(page); } @@ -1177,6 +1178,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, dio->inode = inode; dio->rw = rw; + dio->should_dirty = !(iter->type & ITER_BVEC); /* * For AIO O_(D)SYNC writes we need to defer completions to a workqueue diff --git a/mm/page_io.c b/mm/page_io.c index 955db8b..b9b84b2 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -266,8 +266,8 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, struct address_space *mapping = swap_file->f_mapping; struct bio_vec bv = { .bv_page = page, - .bv_len = PAGE_SIZE, - .bv_offset = 0 + .bv_len = PAGE_SIZE, + .bv_offset = 0, }; struct iov_iter from = { .type = ITER_BVEC | WRITE, @@ -283,8 +283,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, set_page_writeback(page); unlock_page(page); - ret = mapping->a_ops->direct_IO(ITER_BVEC | WRITE, - &kiocb, &from, + ret = mapping->a_ops->direct_IO(WRITE, &kiocb, &from, kiocb.ki_pos); if (ret == PAGE_SIZE) { count_vm_event(PSWPOUT); @@ -303,7 +302,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, set_page_dirty(page); ClearPageReclaim(page); pr_err_ratelimited("Write error on dio swapfile (%Lu)\n", - page_file_offset(page)); + page_file_offset(page)); } end_page_writeback(page); return ret; @@ -348,12 +347,36 @@ int swap_readpage(struct page *page) } if (sis->flags & SWP_FILE) { + struct kiocb kiocb; struct file *swap_file = sis->swap_file; struct address_space *mapping = swap_file->f_mapping; + struct bio_vec bv = { + .bv_page = page, + .bv_len = PAGE_SIZE, + .bv_offset = 0, + }; + struct iov_iter to = { + .type = ITER_BVEC | READ, + .count = PAGE_SIZE, + .iov_offset = 0, + .nr_segs = 1, + }; + to.bvec = &bv; /* older gcc versions are broken */ + + init_sync_kiocb(&kiocb, swap_file); + kiocb.ki_pos = page_file_offset(page); + kiocb.ki_nbytes = PAGE_SIZE; - ret = mapping->a_ops->readpage(swap_file, page); - if (!ret) + ret = mapping->a_ops->direct_IO(READ, &kiocb, &to, + kiocb.ki_pos); + if (ret == PAGE_SIZE) { + SetPageUptodate(page); count_vm_event(PSWPIN); + ret = 0; + } else { + PageError(page); /* XXX: maybe? */ + } + unlock_page(page); return ret; } -- 2.1.3