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mm: memory-failure: update ttu flag inside unmap_poisoned_folio

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Patch series "mm: memory_failure: unmap poisoned folio during migrate
properly", v3.

Fix two bugs during folio migration if the folio is poisoned.


This patch (of 3):

Commit 6da6b1d4a7 ("mm/hwpoison: convert TTU_IGNORE_HWPOISON to
TTU_HWPOISON") introduce TTU_HWPOISON to replace TTU_IGNORE_HWPOISON in
order to stop send SIGBUS signal when accessing an error page after a
memory error on a clean folio.  However during page migration, anon folio
must be set with TTU_HWPOISON during unmap_*().  For pagecache we need
some policy just like the one in hwpoison_user_mappings to set this flag. 
So move this policy from hwpoison_user_mappings to unmap_poisoned_folio to
handle this warning properly.

Warning will be produced during unamp poison folio with the following log:

  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 365 at mm/rmap.c:1847 try_to_unmap_one+0x8fc/0xd3c
  Modules linked in:
  CPU: 1 UID: 0 PID: 365 Comm: bash Tainted: G        W          6.13.0-rc1-00018-gacdb4bbda7ab #42
  Tainted: [W]=WARN
  Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
  pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : try_to_unmap_one+0x8fc/0xd3c
  lr : try_to_unmap_one+0x3dc/0xd3c
  Call trace:
   try_to_unmap_one+0x8fc/0xd3c (P)
   try_to_unmap_one+0x3dc/0xd3c (L)
   rmap_walk_anon+0xdc/0x1f8
   rmap_walk+0x3c/0x58
   try_to_unmap+0x88/0x90
   unmap_poisoned_folio+0x30/0xa8
   do_migrate_range+0x4a0/0x568
   offline_pages+0x5a4/0x670
   memory_block_action+0x17c/0x374
   memory_subsys_offline+0x3c/0x78
   device_offline+0xa4/0xd0
   state_store+0x8c/0xf0
   dev_attr_store+0x18/0x2c
   sysfs_kf_write+0x44/0x54
   kernfs_fop_write_iter+0x118/0x1a8
   vfs_write+0x3a8/0x4bc
   ksys_write+0x6c/0xf8
   __arm64_sys_write+0x1c/0x28
   invoke_syscall+0x44/0x100
   el0_svc_common.constprop.0+0x40/0xe0
   do_el0_svc+0x1c/0x28
   el0_svc+0x30/0xd0
   el0t_64_sync_handler+0xc8/0xcc
   el0t_64_sync+0x198/0x19c
  ---[ end trace 0000000000000000 ]---

[mawupeng1@huawei.com: unmap_poisoned_folio(): remove shadowed local `mapping', per Miaohe]
  Link: https://lkml.kernel.org/r/20250219060653.3849083-1-mawupeng1@huawei.com
Link: https://lkml.kernel.org/r/20250217014329.3610326-1-mawupeng1@huawei.com
Link: https://lkml.kernel.org/r/20250217014329.3610326-2-mawupeng1@huawei.com
Fixes: 6da6b1d4a7 ("mm/hwpoison: convert TTU_IGNORE_HWPOISON to TTU_HWPOISON")
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ma Wupeng <mawupeng1@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Ma Wupeng
2025-02-17 09:43:27 +08:00
committed by Andrew Morton
parent a564ccfe30
commit b81679b163
3 changed files with 36 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
mm/internal.h
View File

@@ -1115,7 +1115,7 @@ static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
* mm/memory-failure.c
*/
#ifdef CONFIG_MEMORY_FAILURE
void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu);
int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill);
void shake_folio(struct folio *folio);
extern int hwpoison_filter(struct page *p);
@@ -1138,8 +1138,9 @@ unsigned long page_mapped_in_vma(const struct page *page,
struct vm_area_struct *vma);
#else
static inline void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
static inline int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill)
{
return -EBUSY;
}
#endif

63
mm/memory-failure.c
View File

@@ -1556,11 +1556,35 @@ static int get_hwpoison_page(struct page *p, unsigned long flags)
return ret;
}
void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill)
{
if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
struct address_space *mapping;
enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON;
struct address_space *mapping;
if (folio_test_swapcache(folio)) {
pr_err("%#lx: keeping poisoned page in swap cache\n", pfn);
ttu &= ~TTU_HWPOISON;
}
/*
* Propagate the dirty bit from PTEs to struct page first, because we
* need this to decide if we should kill or just drop the page.
* XXX: the dirty test could be racy: set_page_dirty() may not always
* be called inside page lock (it's recommended but not enforced).
*/
mapping = folio_mapping(folio);
if (!must_kill && !folio_test_dirty(folio) && mapping &&
mapping_can_writeback(mapping)) {
if (folio_mkclean(folio)) {
folio_set_dirty(folio);
} else {
ttu &= ~TTU_HWPOISON;
pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
pfn);
}
}
if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
/*
* For hugetlb folios in shared mappings, try_to_unmap
* could potentially call huge_pmd_unshare. Because of
@@ -1572,7 +1596,7 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
if (!mapping) {
pr_info("%#lx: could not lock mapping for mapped hugetlb folio\n",
folio_pfn(folio));
return;
return -EBUSY;
}
try_to_unmap(folio, ttu|TTU_RMAP_LOCKED);
@@ -1580,6 +1604,8 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
} else {
try_to_unmap(folio, ttu);
}
return folio_mapped(folio) ? -EBUSY : 0;
}
/*
@@ -1589,8 +1615,6 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
unsigned long pfn, int flags)
{
enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON;
struct address_space *mapping;
LIST_HEAD(tokill);
bool unmap_success;
int forcekill;
@@ -1613,29 +1637,6 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
if (!folio_mapped(folio))
return true;
if (folio_test_swapcache(folio)) {
pr_err("%#lx: keeping poisoned page in swap cache\n", pfn);
ttu &= ~TTU_HWPOISON;
}
/*
* Propagate the dirty bit from PTEs to struct page first, because we
* need this to decide if we should kill or just drop the page.
* XXX: the dirty test could be racy: set_page_dirty() may not always
* be called inside page lock (it's recommended but not enforced).
*/
mapping = folio_mapping(folio);
if (!(flags & MF_MUST_KILL) && !folio_test_dirty(folio) && mapping &&
mapping_can_writeback(mapping)) {
if (folio_mkclean(folio)) {
folio_set_dirty(folio);
} else {
ttu &= ~TTU_HWPOISON;
pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
pfn);
}
}
/*
* First collect all the processes that have the page
* mapped in dirty form. This has to be done before try_to_unmap,
@@ -1643,9 +1644,7 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
*/
collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED);
unmap_poisoned_folio(folio, ttu);
unmap_success = !folio_mapped(folio);
unmap_success = !unmap_poisoned_folio(folio, pfn, flags & MF_MUST_KILL);
if (!unmap_success)
pr_err("%#lx: failed to unmap page (folio mapcount=%d)\n",
pfn, folio_mapcount(folio));

3
mm/memory_hotplug.c
View File

@@ -1833,7 +1833,8 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (WARN_ON(folio_test_lru(folio)))
folio_isolate_lru(folio);
if (folio_mapped(folio))
unmap_poisoned_folio(folio, TTU_IGNORE_MLOCK);
unmap_poisoned_folio(folio, pfn, false);
continue;
}