Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.13 103/156] Revert "swap: fix do_swap_page() race with swapoff" | Date | Thu, 22 Jul 2021 18:31:18 +0200 |
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit c3b39134bbd088b7dce5e5f342ccd6bb9142fd18 which is commit 2799e77529c2a25492a4395db93996e3dacd762d upstream.
It should not have been added to the stable trees, sorry about that.
Link: https://lore.kernel.org/r/YPVgaY6uw59Fqg5x@casper.infradead.org Reported-by: From: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Ying Huang <ying.huang@intel.com> Cc: Alex Shi <alexs@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- include/linux/swap.h | 9 --------- mm/memory.c | 11 ++--------- 2 files changed, 2 insertions(+), 18 deletions(-)
--- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -526,15 +526,6 @@ static inline struct swap_info_struct *s return NULL; } -static inline struct swap_info_struct *get_swap_device(swp_entry_t entry) -{ - return NULL; -} - -static inline void put_swap_device(struct swap_info_struct *si) -{ -} - #define swap_address_space(entry) (NULL) #define get_nr_swap_pages() 0L #define total_swap_pages 0L --- a/mm/memory.c +++ b/mm/memory.c @@ -3353,7 +3353,6 @@ vm_fault_t do_swap_page(struct vm_fault { struct vm_area_struct *vma = vmf->vma; struct page *page = NULL, *swapcache; - struct swap_info_struct *si = NULL; swp_entry_t entry; pte_t pte; int locked; @@ -3381,16 +3380,14 @@ vm_fault_t do_swap_page(struct vm_fault goto out; } - /* Prevent swapoff from happening to us. */ - si = get_swap_device(entry); - if (unlikely(!si)) - goto out; delayacct_set_flag(current, DELAYACCT_PF_SWAPIN); page = lookup_swap_cache(entry, vma, vmf->address); swapcache = page; if (!page) { + struct swap_info_struct *si = swp_swap_info(entry); + if (data_race(si->flags & SWP_SYNCHRONOUS_IO) && __swap_count(entry) == 1) { /* skip swapcache */ @@ -3559,8 +3556,6 @@ vm_fault_t do_swap_page(struct vm_fault unlock: pte_unmap_unlock(vmf->pte, vmf->ptl); out: - if (si) - put_swap_device(si); return ret; out_nomap: pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -3572,8 +3567,6 @@ out_release: unlock_page(swapcache); put_page(swapcache); } - if (si) - put_swap_device(si); return ret; }
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