Commit 3a272031 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman

Merge tag 'libnvdimm-fixes-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Dan writes:
  "libnvdimm/dax 4.19-rc8

   * Fix a livelock in dax_layout_busy_page() present since v4.18. The
     lockup triggers when truncating an actively mapped huge page out of
     a mapping pinned for direct-I/O.

   * Fix mprotect() clobbers of _PAGE_DEVMAP. Broken since v4.5
     mprotect() clears this flag that is needed to communicate the
     liveness of device pages to the get_user_pages() path."

* tag 'libnvdimm-fixes-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  mm: Preserve _PAGE_DEVMAP across mprotect() calls
  filesystem-dax: Fix dax_layout_busy_page() livelock
parents a24a0eb9 4628a645
......@@ -114,7 +114,7 @@
*/
#define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
_PAGE_ACCESSED | H_PAGE_THP_HUGE | _PAGE_PTE | \
_PAGE_SOFT_DIRTY)
_PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
/*
* user access blocked by key
*/
......@@ -132,7 +132,7 @@
*/
#define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
_PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE | \
_PAGE_SOFT_DIRTY)
_PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
#define H_PTE_PKEY (H_PTE_PKEY_BIT0 | H_PTE_PKEY_BIT1 | H_PTE_PKEY_BIT2 | \
H_PTE_PKEY_BIT3 | H_PTE_PKEY_BIT4)
......
......@@ -124,7 +124,7 @@
*/
#define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \
_PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \
_PAGE_SOFT_DIRTY)
_PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
#define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE)
/*
......
......@@ -666,6 +666,8 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
while (index < end && pagevec_lookup_entries(&pvec, mapping, index,
min(end - index, (pgoff_t)PAGEVEC_SIZE),
indices)) {
pgoff_t nr_pages = 1;
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *pvec_ent = pvec.pages[i];
void *entry;
......@@ -680,8 +682,15 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
xa_lock_irq(&mapping->i_pages);
entry = get_unlocked_mapping_entry(mapping, index, NULL);
if (entry)
if (entry) {
page = dax_busy_page(entry);
/*
* Account for multi-order entries at
* the end of the pagevec.
*/
if (i + 1 >= pagevec_count(&pvec))
nr_pages = 1UL << dax_radix_order(entry);
}
put_unlocked_mapping_entry(mapping, index, entry);
xa_unlock_irq(&mapping->i_pages);
if (page)
......@@ -696,7 +705,7 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
*/
pagevec_remove_exceptionals(&pvec);
pagevec_release(&pvec);
index++;
index += nr_pages;
if (page)
break;
......
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