kernel/linux.git/mm/swapfile.c, branch v6.7

mm/swap: Convert to use bdev_open_by_dev()

2023-10-28T11:29:19+00:00

Convert swapping code to use bdev_open_by_dev() and pass the handle around. CC: linux-mm@kvack.org CC: Andrew Morton Acked-by: Christoph Hellwig Acked-by: Christian Brauner Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230927093442.25915-18-jack@suse.cz Signed-off-by: Christian Brauner

mm/swap: inline folio_set_swap_entry() and folio_swap_entry()

2023-08-24T23:20:28+00:00

Let's simply work on the folio directly and remove the helpers. Link: https://lkml.kernel.org/r/20230821160849.531668-4-david@redhat.com Signed-off-by: David Hildenbrand Suggested-by: Matthew Wilcox Reviewed-by: Chris Li Cc: Catalin Marinas Cc: Dan Streetman Cc: Hugh Dickins Cc: Peter Xu Cc: Seth Jennings Cc: Vitaly Wool Cc: Will Deacon Signed-off-by: Andrew Morton

mm/swap: stop using page->private on tail pages for THP_SWAP

2023-08-24T23:20:28+00:00

Patch series "mm/swap: stop using page->private on tail pages for THP_SWAP + cleanups". This series stops using page->private on tail pages for THP_SWAP, replaces folio->private by folio->swap for swapcache folios, and starts using "new_folio" for tail pages that we are splitting to remove the usage of page->private for swapcache handling completely. This patch (of 4): Let's stop using page->private on tail pages, making it possible to just unconditionally reuse that field in the tail pages of large folios. The remaining usage of the private field for THP_SWAP is in the THP splitting code (mm/huge_memory.c), that we'll handle separately later. Update the THP_SWAP documentation and sanity checks in mm_types.h and __split_huge_page_tail(). [david@redhat.com: stop using page->private on tail pages for THP_SWAP] Link: https://lkml.kernel.org/r/6f0a82a3-6948-20d9-580b-be1dbf415701@redhat.com Link: https://lkml.kernel.org/r/20230821160849.531668-1-david@redhat.com Link: https://lkml.kernel.org/r/20230821160849.531668-2-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Catalin Marinas [arm64] Reviewed-by: Yosry Ahmed Cc: Dan Streetman Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Seth Jennings Cc: Vitaly Wool Cc: Will Deacon Signed-off-by: Andrew Morton

merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes

2023-08-21T21:26:20+00:00

mm/swapfile.c: use helper macro K()

2023-08-21T20:37:44+00:00

Use helper macro K() to improve code readability. No functional modification involved. Link: https://lkml.kernel.org/r/20230804012559.2617515-3-zhangpeng362@huawei.com Signed-off-by: ZhangPeng Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Cc: Kefeng Wang Cc: Nanyong Sun Signed-off-by: Andrew Morton

mm: kill frontswap

2023-08-21T20:37:26+00:00

The only user of frontswap is zswap, and has been for a long time. Have swap call into zswap directly and remove the indirection. [hannes@cmpxchg.org: remove obsolete comment, per Yosry] Link: https://lkml.kernel.org/r/20230719142832.GA932528@cmpxchg.org [fengwei.yin@intel.com: don't warn if none swapcache folio is passed to zswap_load] Link: https://lkml.kernel.org/r/20230810095652.3905184-1-fengwei.yin@intel.com Link: https://lkml.kernel.org/r/20230717160227.GA867137@cmpxchg.org Signed-off-by: Johannes Weiner Signed-off-by: Yin Fengwei Acked-by: Konrad Rzeszutek Wilk Acked-by: Nhat Pham Acked-by: Yosry Ahmed Acked-by: Christoph Hellwig Cc: Domenico Cerasuolo Cc: Matthew Wilcox (Oracle) Cc: Vitaly Wool Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: make PTE_MARKER_SWAPIN_ERROR more general

2023-08-18T17:12:16+00:00

Patch series "add UFFDIO_POISON to simulate memory poisoning with UFFD", v4. This series adds a new userfaultfd feature, UFFDIO_POISON. See commit 4 for a detailed description of the feature. This patch (of 8): Future patches will reuse PTE_MARKER_SWAPIN_ERROR to implement UFFDIO_POISON, so make some various preparations for that: First, rename it to just PTE_MARKER_POISONED. The "SWAPIN" can be confusing since we're going to re-use it for something not really related to swap. This can be particularly confusing for things like hugetlbfs, which doesn't support swap whatsoever. Also rename some various helper functions. Next, fix pte marker copying for hugetlbfs. Previously, it would WARN on seeing a PTE_MARKER_SWAPIN_ERROR, since hugetlbfs doesn't support swap. But, since we're going to re-use it, we want it to go ahead and copy it just like non-hugetlbfs memory does today. Since the code to do this is more complicated now, pull it out into a helper which can be re-used in both places. While we're at it, also make it slightly more explicit in its handling of e.g. uffd wp markers. For non-hugetlbfs page faults, instead of returning VM_FAULT_SIGBUS for an error entry, return VM_FAULT_HWPOISON. For most cases this change doesn't matter, e.g. a userspace program would receive a SIGBUS either way. But for UFFDIO_POISON, this change will let KVM guests get an MCE out of the box, instead of giving a SIGBUS to the hypervisor and requiring it to somehow inject an MCE. Finally, for hugetlbfs faults, handle PTE_MARKER_POISONED, and return VM_FAULT_HWPOISON_LARGE in such cases. Note that this can't happen today because the lack of swap support means we'll never end up with such a PTE anyway, but this behavior will be needed once such entries *can* show up via UFFDIO_POISON. Link: https://lkml.kernel.org/r/20230707215540.2324998-1-axelrasmussen@google.com Link: https://lkml.kernel.org/r/20230707215540.2324998-2-axelrasmussen@google.com Signed-off-by: Axel Rasmussen Acked-by: Peter Xu Cc: Al Viro Cc: Brian Geffon Cc: Christian Brauner Cc: David Hildenbrand Cc: Gaosheng Cui Cc: Huang, Ying Cc: Hugh Dickins Cc: James Houghton Cc: Jan Alexander Steffens (heftig) Cc: Jiaqi Yan Cc: Jonathan Corbet Cc: Kefeng Wang Cc: Liam R. Howlett Cc: Miaohe Lin Cc: Mike Kravetz Cc: Mike Rapoport (IBM) Cc: Muchun Song Cc: Nadav Amit Cc: Naoya Horiguchi Cc: Ryan Roberts Cc: Shuah Khan Cc: Suleiman Souhlal Cc: Suren Baghdasaryan Cc: T.J. Alumbaugh Cc: Yu Zhao Cc: ZhangPeng Signed-off-by: Andrew Morton

mm: call arch_swap_restore() from unuse_pte()

2023-08-18T17:12:02+00:00

We would like to move away from requiring architectures to restore metadata from swap in the set_pte_at() implementation, as this is not only error-prone but adds complexity to the arch-specific code. This requires us to call arch_swap_restore() before calling swap_free() whenever pages are restored from swap. We are currently doing so everywhere except in unuse_pte(); do so there as well. Link: https://lkml.kernel.org/r/20230523004312.1807357-3-pcc@google.com Link: https://linux-review.googlesource.com/id/I68276653e612d64cde271ce1b5a99ae05d6bbc4f Signed-off-by: Peter Collingbourne Suggested-by: David Hildenbrand Acked-by: David Hildenbrand Acked-by: "Huang, Ying" Reviewed-by: Steven Price Acked-by: Catalin Marinas Cc: Alexandru Elisei Cc: Chinwen Chang Cc: Evgenii Stepanov Cc: Greg Kroah-Hartman Cc: kasan-dev Cc: "Kuan-Ying Lee (李冠穎)" Cc: Qun-Wei Lin Cc: Suren Baghdasaryan Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton

swap: stop add to avail list if swap is full

2023-08-18T17:12:00+00:00

Our test finds a WARN_ON in add_to_avail_list. During add_to_avail_list, avail_lists is already in swap_avail_heads, while leads to this WARN_ON. Here is the simplified calltrace: ------------[ cut here ]------------ Call trace: add_to_avail_list+0xb8/0xc0 swap_range_free+0x110/0x138 swapcache_free_entries+0x100/0x1c0 free_swap_slot+0xbc/0xe0 put_swap_folio+0x1f0/0x2ec delete_from_swap_cache+0x6c/0xd0 folio_free_swap+0xa4/0xe4 __try_to_reclaim_swap+0x9c/0x190 free_swap_and_cache+0x84/0x88 unmap_page_range+0x31c/0x934 unmap_single_vma.isra.0+0x48/0x84 unmap_vmas+0x98/0x10c exit_mmap+0xa4/0x210 mmput+0x88/0x158 do_exit+0x284/0x970 do_group_exit+0x34/0x90 post_copy_siginfo_from_user32+0x0/0x1cc do_notify_resume+0x15c/0x470 el0_svc+0x74/0x84 el0t_64_sync_handler+0xb8/0xbc el0t_64_sync+0x190/0x194 During swapoff, try_to_unuse fails to alloc memory due to memory limit and this leads to the failure of swapoff and causes re-insertion of swap space back into swap_list. During _enable_swap_info, this swap device is added to avail list even this swap device if full. At the same time, one entry in this full swap device in released and we try to add this device into avail list and find it is already in the avail list. This causes this WARN_ON. To fix this. Don't add to avail list is swap is full. [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/20230627120833.2230766-3-mawupeng1@huawei.com Signed-off-by: Ma Wupeng Cc: Hugh Dickins Signed-off-by: Andrew Morton

swap: cleanup duplicated WARN_ON in add_to_avail_list

2023-08-18T17:12:00+00:00

Patch series "fix WARN_ON in add_to_avail_list". Empty check for plist_node is checked in add_to_avail_list and plist_add. Drop the duplicate one in add_to_avail_list. Link: https://lkml.kernel.org/r/20230627120833.2230766-1-mawupeng1@huawei.com Link: https://lkml.kernel.org/r/20230627120833.2230766-2-mawupeng1@huawei.com Signed-off-by: Ma Wupeng Cc: Hugh Dickins Signed-off-by: Andrew Morton