From a1a0dfd56f97738c1974976309bbf38bb5a21132 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 9 May 2022 18:20:49 -0700 Subject: mm: handle THP in swap_*page_fs() Pages passed to swap_readpage()/swap_writepage() are not necessarily all the same size - there may be transparent-huge-pages involves. The BIO paths of swap_*page() handle this correctly, but the SWP_FS_OPS path does not. So we need to use thp_size() to find the size, not just assume PAGE_SIZE, and we need to track the total length of the request, not just assume it is "page * PAGE_SIZE". Link: https://lkml.kernel.org/r/165119301488.15698.9457662928942765453.stgit@noble.brown Signed-off-by: NeilBrown Reported-by: Miaohe Lin Cc: Christoph Hellwig Cc: David Howells Cc: Geert Uytterhoeven Cc: Hugh Dickins Cc: Mel Gorman Cc: Trond Myklebust Signed-off-by: Andrew Morton --- mm/page_io.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'mm') diff --git a/mm/page_io.c b/mm/page_io.c index c132511f521c..d636a3531cad 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -239,6 +239,7 @@ struct swap_iocb { struct kiocb iocb; struct bio_vec bvec[SWAP_CLUSTER_MAX]; int pages; + int len; }; static mempool_t *sio_pool; @@ -261,7 +262,7 @@ static void sio_write_complete(struct kiocb *iocb, long ret) struct page *page = sio->bvec[0].bv_page; int p; - if (ret != PAGE_SIZE * sio->pages) { + if (ret != sio->len) { /* * In the case of swap-over-nfs, this can be a * temporary failure if the system has limited @@ -301,7 +302,7 @@ static int swap_writepage_fs(struct page *page, struct writeback_control *wbc) sio = *wbc->swap_plug; if (sio) { if (sio->iocb.ki_filp != swap_file || - sio->iocb.ki_pos + sio->pages * PAGE_SIZE != pos) { + sio->iocb.ki_pos + sio->len != pos) { swap_write_unplug(sio); sio = NULL; } @@ -312,10 +313,12 @@ static int swap_writepage_fs(struct page *page, struct writeback_control *wbc) sio->iocb.ki_complete = sio_write_complete; sio->iocb.ki_pos = pos; sio->pages = 0; + sio->len = 0; } sio->bvec[sio->pages].bv_page = page; - sio->bvec[sio->pages].bv_len = PAGE_SIZE; + sio->bvec[sio->pages].bv_len = thp_size(page); sio->bvec[sio->pages].bv_offset = 0; + sio->len += thp_size(page); sio->pages += 1; if (sio->pages == ARRAY_SIZE(sio->bvec) || !wbc->swap_plug) { swap_write_unplug(sio); @@ -371,8 +374,7 @@ void swap_write_unplug(struct swap_iocb *sio) struct address_space *mapping = sio->iocb.ki_filp->f_mapping; int ret; - iov_iter_bvec(&from, WRITE, sio->bvec, sio->pages, - PAGE_SIZE * sio->pages); + iov_iter_bvec(&from, WRITE, sio->bvec, sio->pages, sio->len); ret = mapping->a_ops->swap_rw(&sio->iocb, &from); if (ret != -EIOCBQUEUED) sio_write_complete(&sio->iocb, ret); @@ -383,7 +385,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret) struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb); int p; - if (ret == PAGE_SIZE * sio->pages) { + if (ret == sio->len) { for (p = 0; p < sio->pages; p++) { struct page *page = sio->bvec[p].bv_page; @@ -415,7 +417,7 @@ static void swap_readpage_fs(struct page *page, sio = *plug; if (sio) { if (sio->iocb.ki_filp != sis->swap_file || - sio->iocb.ki_pos + sio->pages * PAGE_SIZE != pos) { + sio->iocb.ki_pos + sio->len != pos) { swap_read_unplug(sio); sio = NULL; } @@ -426,10 +428,12 @@ static void swap_readpage_fs(struct page *page, sio->iocb.ki_pos = pos; sio->iocb.ki_complete = sio_read_complete; sio->pages = 0; + sio->len = 0; } sio->bvec[sio->pages].bv_page = page; - sio->bvec[sio->pages].bv_len = PAGE_SIZE; + sio->bvec[sio->pages].bv_len = thp_size(page); sio->bvec[sio->pages].bv_offset = 0; + sio->len += thp_size(page); sio->pages += 1; if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) { swap_read_unplug(sio); @@ -521,8 +525,7 @@ void __swap_read_unplug(struct swap_iocb *sio) struct address_space *mapping = sio->iocb.ki_filp->f_mapping; int ret; - iov_iter_bvec(&from, READ, sio->bvec, sio->pages, - PAGE_SIZE * sio->pages); + iov_iter_bvec(&from, READ, sio->bvec, sio->pages, sio->len); ret = mapping->a_ops->swap_rw(&sio->iocb, &from); if (ret != -EIOCBQUEUED) sio_read_complete(&sio->iocb, ret); -- cgit v1.2.3