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-rw-r--r--mm/mlock.c638
1 files changed, 266 insertions, 372 deletions
diff --git a/mm/mlock.c b/mm/mlock.c
index 349e2cda8c50..efd2dd2943de 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -14,6 +14,7 @@
#include <linux/swapops.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
+#include <linux/pagewalk.h>
#include <linux/mempolicy.h>
#include <linux/syscalls.h>
#include <linux/sched.h>
@@ -27,6 +28,8 @@
#include "internal.h"
+static DEFINE_PER_CPU(struct pagevec, mlock_pvec);
+
bool can_do_mlock(void)
{
if (rlimit(RLIMIT_MEMLOCK) != 0)
@@ -46,441 +49,320 @@ EXPORT_SYMBOL(can_do_mlock);
* be placed on the LRU "unevictable" list, rather than the [in]active lists.
* The unevictable list is an LRU sibling list to the [in]active lists.
* PageUnevictable is set to indicate the unevictable state.
- *
- * When lazy mlocking via vmscan, it is important to ensure that the
- * vma's VM_LOCKED status is not concurrently being modified, otherwise we
- * may have mlocked a page that is being munlocked. So lazy mlock must take
- * the mmap_lock for read, and verify that the vma really is locked
- * (see mm/rmap.c).
*/
-/*
- * LRU accounting for clear_page_mlock()
- */
-void clear_page_mlock(struct page *page)
+static struct lruvec *__mlock_page(struct page *page, struct lruvec *lruvec)
{
- int nr_pages;
+ /* There is nothing more we can do while it's off LRU */
+ if (!TestClearPageLRU(page))
+ return lruvec;
- if (!TestClearPageMlocked(page))
- return;
+ lruvec = folio_lruvec_relock_irq(page_folio(page), lruvec);
- nr_pages = thp_nr_pages(page);
- mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
- count_vm_events(UNEVICTABLE_PGCLEARED, nr_pages);
- /*
- * The previous TestClearPageMlocked() corresponds to the smp_mb()
- * in __pagevec_lru_add_fn().
- *
- * See __pagevec_lru_add_fn for more explanation.
- */
- if (!isolate_lru_page(page)) {
- putback_lru_page(page);
- } else {
+ if (unlikely(page_evictable(page))) {
/*
- * We lost the race. the page already moved to evictable list.
+ * This is a little surprising, but quite possible:
+ * PageMlocked must have got cleared already by another CPU.
+ * Could this page be on the Unevictable LRU? I'm not sure,
+ * but move it now if so.
*/
- if (PageUnevictable(page))
- count_vm_events(UNEVICTABLE_PGSTRANDED, nr_pages);
+ if (PageUnevictable(page)) {
+ del_page_from_lru_list(page, lruvec);
+ ClearPageUnevictable(page);
+ add_page_to_lru_list(page, lruvec);
+ __count_vm_events(UNEVICTABLE_PGRESCUED,
+ thp_nr_pages(page));
+ }
+ goto out;
}
+
+ if (PageUnevictable(page)) {
+ if (PageMlocked(page))
+ page->mlock_count++;
+ goto out;
+ }
+
+ del_page_from_lru_list(page, lruvec);
+ ClearPageActive(page);
+ SetPageUnevictable(page);
+ page->mlock_count = !!PageMlocked(page);
+ add_page_to_lru_list(page, lruvec);
+ __count_vm_events(UNEVICTABLE_PGCULLED, thp_nr_pages(page));
+out:
+ SetPageLRU(page);
+ return lruvec;
}
-/*
- * Mark page as mlocked if not already.
- * If page on LRU, isolate and putback to move to unevictable list.
- */
-void mlock_vma_page(struct page *page)
+static struct lruvec *__mlock_new_page(struct page *page, struct lruvec *lruvec)
{
- /* Serialize with page migration */
- BUG_ON(!PageLocked(page));
+ VM_BUG_ON_PAGE(PageLRU(page), page);
- VM_BUG_ON_PAGE(PageTail(page), page);
- VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page);
+ lruvec = folio_lruvec_relock_irq(page_folio(page), lruvec);
- if (!TestSetPageMlocked(page)) {
- int nr_pages = thp_nr_pages(page);
+ /* As above, this is a little surprising, but possible */
+ if (unlikely(page_evictable(page)))
+ goto out;
- mod_zone_page_state(page_zone(page), NR_MLOCK, nr_pages);
- count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages);
- if (!isolate_lru_page(page))
- putback_lru_page(page);
- }
+ SetPageUnevictable(page);
+ page->mlock_count = !!PageMlocked(page);
+ __count_vm_events(UNEVICTABLE_PGCULLED, thp_nr_pages(page));
+out:
+ add_page_to_lru_list(page, lruvec);
+ SetPageLRU(page);
+ return lruvec;
}
-/*
- * Finish munlock after successful page isolation
- *
- * Page must be locked. This is a wrapper for page_mlock()
- * and putback_lru_page() with munlock accounting.
- */
-static void __munlock_isolated_page(struct page *page)
+static struct lruvec *__munlock_page(struct page *page, struct lruvec *lruvec)
{
- /*
- * Optimization: if the page was mapped just once, that's our mapping
- * and we don't need to check all the other vmas.
- */
- if (page_mapcount(page) > 1)
- page_mlock(page);
+ int nr_pages = thp_nr_pages(page);
+ bool isolated = false;
+
+ if (!TestClearPageLRU(page))
+ goto munlock;
- /* Did try_to_unlock() succeed or punt? */
- if (!PageMlocked(page))
- count_vm_events(UNEVICTABLE_PGMUNLOCKED, thp_nr_pages(page));
+ isolated = true;
+ lruvec = folio_lruvec_relock_irq(page_folio(page), lruvec);
- putback_lru_page(page);
+ if (PageUnevictable(page)) {
+ /* Then mlock_count is maintained, but might undercount */
+ if (page->mlock_count)
+ page->mlock_count--;
+ if (page->mlock_count)
+ goto out;
+ }
+ /* else assume that was the last mlock: reclaim will fix it if not */
+
+munlock:
+ if (TestClearPageMlocked(page)) {
+ __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
+ if (isolated || !PageUnevictable(page))
+ __count_vm_events(UNEVICTABLE_PGMUNLOCKED, nr_pages);
+ else
+ __count_vm_events(UNEVICTABLE_PGSTRANDED, nr_pages);
+ }
+
+ /* page_evictable() has to be checked *after* clearing Mlocked */
+ if (isolated && PageUnevictable(page) && page_evictable(page)) {
+ del_page_from_lru_list(page, lruvec);
+ ClearPageUnevictable(page);
+ add_page_to_lru_list(page, lruvec);
+ __count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
+ }
+out:
+ if (isolated)
+ SetPageLRU(page);
+ return lruvec;
}
/*
- * Accounting for page isolation fail during munlock
- *
- * Performs accounting when page isolation fails in munlock. There is nothing
- * else to do because it means some other task has already removed the page
- * from the LRU. putback_lru_page() will take care of removing the page from
- * the unevictable list, if necessary. vmscan [page_referenced()] will move
- * the page back to the unevictable list if some other vma has it mlocked.
+ * Flags held in the low bits of a struct page pointer on the mlock_pvec.
*/
-static void __munlock_isolation_failed(struct page *page)
+#define LRU_PAGE 0x1
+#define NEW_PAGE 0x2
+static inline struct page *mlock_lru(struct page *page)
{
- int nr_pages = thp_nr_pages(page);
+ return (struct page *)((unsigned long)page + LRU_PAGE);
+}
- if (PageUnevictable(page))
- __count_vm_events(UNEVICTABLE_PGSTRANDED, nr_pages);
- else
- __count_vm_events(UNEVICTABLE_PGMUNLOCKED, nr_pages);
+static inline struct page *mlock_new(struct page *page)
+{
+ return (struct page *)((unsigned long)page + NEW_PAGE);
}
-/**
- * munlock_vma_page - munlock a vma page
- * @page: page to be unlocked, either a normal page or THP page head
- *
- * returns the size of the page as a page mask (0 for normal page,
- * HPAGE_PMD_NR - 1 for THP head page)
- *
- * called from munlock()/munmap() path with page supposedly on the LRU.
- * When we munlock a page, because the vma where we found the page is being
- * munlock()ed or munmap()ed, we want to check whether other vmas hold the
- * page locked so that we can leave it on the unevictable lru list and not
- * bother vmscan with it. However, to walk the page's rmap list in
- * page_mlock() we must isolate the page from the LRU. If some other
- * task has removed the page from the LRU, we won't be able to do that.
- * So we clear the PageMlocked as we might not get another chance. If we
- * can't isolate the page, we leave it for putback_lru_page() and vmscan
- * [page_referenced()/try_to_unmap()] to deal with.
+/*
+ * mlock_pagevec() is derived from pagevec_lru_move_fn():
+ * perhaps that can make use of such page pointer flags in future,
+ * but for now just keep it for mlock. We could use three separate
+ * pagevecs instead, but one feels better (munlocking a full pagevec
+ * does not need to drain mlocking pagevecs first).
*/
-unsigned int munlock_vma_page(struct page *page)
+static void mlock_pagevec(struct pagevec *pvec)
{
- int nr_pages;
-
- /* For page_mlock() and to serialize with page migration */
- BUG_ON(!PageLocked(page));
- VM_BUG_ON_PAGE(PageTail(page), page);
+ struct lruvec *lruvec = NULL;
+ unsigned long mlock;
+ struct page *page;
+ int i;
- if (!TestClearPageMlocked(page)) {
- /* Potentially, PTE-mapped THP: do not skip the rest PTEs */
- return 0;
+ for (i = 0; i < pagevec_count(pvec); i++) {
+ page = pvec->pages[i];
+ mlock = (unsigned long)page & (LRU_PAGE | NEW_PAGE);
+ page = (struct page *)((unsigned long)page - mlock);
+ pvec->pages[i] = page;
+
+ if (mlock & LRU_PAGE)
+ lruvec = __mlock_page(page, lruvec);
+ else if (mlock & NEW_PAGE)
+ lruvec = __mlock_new_page(page, lruvec);
+ else
+ lruvec = __munlock_page(page, lruvec);
}
- nr_pages = thp_nr_pages(page);
- mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
+ if (lruvec)
+ unlock_page_lruvec_irq(lruvec);
+ release_pages(pvec->pages, pvec->nr);
+ pagevec_reinit(pvec);
+}
- if (!isolate_lru_page(page))
- __munlock_isolated_page(page);
- else
- __munlock_isolation_failed(page);
+void mlock_page_drain(int cpu)
+{
+ struct pagevec *pvec;
- return nr_pages - 1;
+ pvec = &per_cpu(mlock_pvec, cpu);
+ if (pagevec_count(pvec))
+ mlock_pagevec(pvec);
}
-/*
- * convert get_user_pages() return value to posix mlock() error
- */
-static int __mlock_posix_error_return(long retval)
+bool need_mlock_page_drain(int cpu)
{
- if (retval == -EFAULT)
- retval = -ENOMEM;
- else if (retval == -ENOMEM)
- retval = -EAGAIN;
- return retval;
+ return pagevec_count(&per_cpu(mlock_pvec, cpu));
}
-/*
- * Prepare page for fast batched LRU putback via putback_lru_evictable_pagevec()
- *
- * The fast path is available only for evictable pages with single mapping.
- * Then we can bypass the per-cpu pvec and get better performance.
- * when mapcount > 1 we need page_mlock() which can fail.
- * when !page_evictable(), we need the full redo logic of putback_lru_page to
- * avoid leaving evictable page in unevictable list.
- *
- * In case of success, @page is added to @pvec and @pgrescued is incremented
- * in case that the page was previously unevictable. @page is also unlocked.
+/**
+ * mlock_folio - mlock a folio already on (or temporarily off) LRU
+ * @folio: folio to be mlocked.
*/
-static bool __putback_lru_fast_prepare(struct page *page, struct pagevec *pvec,
- int *pgrescued)
+void mlock_folio(struct folio *folio)
{
- VM_BUG_ON_PAGE(PageLRU(page), page);
- VM_BUG_ON_PAGE(!PageLocked(page), page);
+ struct pagevec *pvec = &get_cpu_var(mlock_pvec);
- if (page_mapcount(page) <= 1 && page_evictable(page)) {
- pagevec_add(pvec, page);
- if (TestClearPageUnevictable(page))
- (*pgrescued)++;
- unlock_page(page);
- return true;
+ if (!folio_test_set_mlocked(folio)) {
+ int nr_pages = folio_nr_pages(folio);
+
+ zone_stat_mod_folio(folio, NR_MLOCK, nr_pages);
+ __count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages);
}
- return false;
+ folio_get(folio);
+ if (!pagevec_add(pvec, mlock_lru(&folio->page)) ||
+ folio_test_large(folio) || lru_cache_disabled())
+ mlock_pagevec(pvec);
+ put_cpu_var(mlock_pvec);
}
-/*
- * Putback multiple evictable pages to the LRU
- *
- * Batched putback of evictable pages that bypasses the per-cpu pvec. Some of
- * the pages might have meanwhile become unevictable but that is OK.
+/**
+ * mlock_new_page - mlock a newly allocated page not yet on LRU
+ * @page: page to be mlocked, either a normal page or a THP head.
*/
-static void __putback_lru_fast(struct pagevec *pvec, int pgrescued)
+void mlock_new_page(struct page *page)
{
- count_vm_events(UNEVICTABLE_PGMUNLOCKED, pagevec_count(pvec));
- /*
- *__pagevec_lru_add() calls release_pages() so we don't call
- * put_page() explicitly
- */
- __pagevec_lru_add(pvec);
- count_vm_events(UNEVICTABLE_PGRESCUED, pgrescued);
+ struct pagevec *pvec = &get_cpu_var(mlock_pvec);
+ int nr_pages = thp_nr_pages(page);
+
+ SetPageMlocked(page);
+ mod_zone_page_state(page_zone(page), NR_MLOCK, nr_pages);
+ __count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages);
+
+ get_page(page);
+ if (!pagevec_add(pvec, mlock_new(page)) ||
+ PageHead(page) || lru_cache_disabled())
+ mlock_pagevec(pvec);
+ put_cpu_var(mlock_pvec);
}
-/*
- * Munlock a batch of pages from the same zone
- *
- * The work is split to two main phases. First phase clears the Mlocked flag
- * and attempts to isolate the pages, all under a single zone lru lock.
- * The second phase finishes the munlock only for pages where isolation
- * succeeded.
- *
- * Note that the pagevec may be modified during the process.
+/**
+ * munlock_page - munlock a page
+ * @page: page to be munlocked, either a normal page or a THP head.
*/
-static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
+void munlock_page(struct page *page)
{
- int i;
- int nr = pagevec_count(pvec);
- int delta_munlocked = -nr;
- struct pagevec pvec_putback;
- struct lruvec *lruvec = NULL;
- int pgrescued = 0;
-
- pagevec_init(&pvec_putback);
-
- /* Phase 1: page isolation */
- for (i = 0; i < nr; i++) {
- struct page *page = pvec->pages[i];
- struct folio *folio = page_folio(page);
-
- if (TestClearPageMlocked(page)) {
- /*
- * We already have pin from follow_page_mask()
- * so we can spare the get_page() here.
- */
- if (TestClearPageLRU(page)) {
- lruvec = folio_lruvec_relock_irq(folio, lruvec);
- del_page_from_lru_list(page, lruvec);
- continue;
- } else
- __munlock_isolation_failed(page);
- } else {
- delta_munlocked++;
- }
-
- /*
- * We won't be munlocking this page in the next phase
- * but we still need to release the follow_page_mask()
- * pin. We cannot do it under lru_lock however. If it's
- * the last pin, __page_cache_release() would deadlock.
- */
- pagevec_add(&pvec_putback, pvec->pages[i]);
- pvec->pages[i] = NULL;
- }
- if (lruvec) {
- __mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
- unlock_page_lruvec_irq(lruvec);
- } else if (delta_munlocked) {
- mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
- }
-
- /* Now we can release pins of pages that we are not munlocking */
- pagevec_release(&pvec_putback);
-
- /* Phase 2: page munlock */
- for (i = 0; i < nr; i++) {
- struct page *page = pvec->pages[i];
-
- if (page) {
- lock_page(page);
- if (!__putback_lru_fast_prepare(page, &pvec_putback,
- &pgrescued)) {
- /*
- * Slow path. We don't want to lose the last
- * pin before unlock_page()
- */
- get_page(page); /* for putback_lru_page() */
- __munlock_isolated_page(page);
- unlock_page(page);
- put_page(page); /* from follow_page_mask() */
- }
- }
- }
+ struct pagevec *pvec = &get_cpu_var(mlock_pvec);
/*
- * Phase 3: page putback for pages that qualified for the fast path
- * This will also call put_page() to return pin from follow_page_mask()
+ * TestClearPageMlocked(page) must be left to __munlock_page(),
+ * which will check whether the page is multiply mlocked.
*/
- if (pagevec_count(&pvec_putback))
- __putback_lru_fast(&pvec_putback, pgrescued);
+
+ get_page(page);
+ if (!pagevec_add(pvec, page) ||
+ PageHead(page) || lru_cache_disabled())
+ mlock_pagevec(pvec);
+ put_cpu_var(mlock_pvec);
}
-/*
- * Fill up pagevec for __munlock_pagevec using pte walk
- *
- * The function expects that the struct page corresponding to @start address is
- * a non-TPH page already pinned and in the @pvec, and that it belongs to @zone.
- *
- * The rest of @pvec is filled by subsequent pages within the same pmd and same
- * zone, as long as the pte's are present and vm_normal_page() succeeds. These
- * pages also get pinned.
- *
- * Returns the address of the next page that should be scanned. This equals
- * @start + PAGE_SIZE when no page could be added by the pte walk.
- */
-static unsigned long __munlock_pagevec_fill(struct pagevec *pvec,
- struct vm_area_struct *vma, struct zone *zone,
- unsigned long start, unsigned long end)
+static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, struct mm_walk *walk)
+
{
- pte_t *pte;
+ struct vm_area_struct *vma = walk->vma;
spinlock_t *ptl;
+ pte_t *start_pte, *pte;
+ struct page *page;
- /*
- * Initialize pte walk starting at the already pinned page where we
- * are sure that there is a pte, as it was pinned under the same
- * mmap_lock write op.
- */
- pte = get_locked_pte(vma->vm_mm, start, &ptl);
- /* Make sure we do not cross the page table boundary */
- end = pgd_addr_end(start, end);
- end = p4d_addr_end(start, end);
- end = pud_addr_end(start, end);
- end = pmd_addr_end(start, end);
-
- /* The page next to the pinned page is the first we will try to get */
- start += PAGE_SIZE;
- while (start < end) {
- struct page *page = NULL;
- pte++;
- if (pte_present(*pte))
- page = vm_normal_page(vma, start, *pte);
- /*
- * Break if page could not be obtained or the page's node+zone does not
- * match
- */
- if (!page || page_zone(page) != zone)
- break;
+ ptl = pmd_trans_huge_lock(pmd, vma);
+ if (ptl) {
+ if (!pmd_present(*pmd))
+ goto out;
+ if (is_huge_zero_pmd(*pmd))
+ goto out;
+ page = pmd_page(*pmd);
+ if (vma->vm_flags & VM_LOCKED)
+ mlock_folio(page_folio(page));
+ else
+ munlock_page(page);
+ goto out;
+ }
- /*
- * Do not use pagevec for PTE-mapped THP,
- * munlock_vma_pages_range() will handle them.
- */
+ start_pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (pte = start_pte; addr != end; pte++, addr += PAGE_SIZE) {
+ if (!pte_present(*pte))
+ continue;
+ page = vm_normal_page(vma, addr, *pte);
+ if (!page)
+ continue;
if (PageTransCompound(page))
- break;
-
- get_page(page);
- /*
- * Increase the address that will be returned *before* the
- * eventual break due to pvec becoming full by adding the page
- */
- start += PAGE_SIZE;
- if (pagevec_add(pvec, page) == 0)
- break;
+ continue;
+ if (vma->vm_flags & VM_LOCKED)
+ mlock_folio(page_folio(page));
+ else
+ munlock_page(page);
}
- pte_unmap_unlock(pte, ptl);
- return start;
+ pte_unmap(start_pte);
+out:
+ spin_unlock(ptl);
+ cond_resched();
+ return 0;
}
/*
- * munlock_vma_pages_range() - munlock all pages in the vma range.'
- * @vma - vma containing range to be munlock()ed.
+ * mlock_vma_pages_range() - mlock any pages already in the range,
+ * or munlock all pages in the range.
+ * @vma - vma containing range to be mlock()ed or munlock()ed
* @start - start address in @vma of the range
- * @end - end of range in @vma.
+ * @end - end of range in @vma
+ * @newflags - the new set of flags for @vma.
*
- * For mremap(), munmap() and exit().
- *
- * Called with @vma VM_LOCKED.
- *
- * Returns with VM_LOCKED cleared. Callers must be prepared to
- * deal with this.
- *
- * We don't save and restore VM_LOCKED here because pages are
- * still on lru. In unmap path, pages might be scanned by reclaim
- * and re-mlocked by page_mlock/try_to_unmap before we unmap and
- * free them. This will result in freeing mlocked pages.
+ * Called for mlock(), mlock2() and mlockall(), to set @vma VM_LOCKED;
+ * called for munlock() and munlockall(), to clear VM_LOCKED from @vma.
*/
-void munlock_vma_pages_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+static void mlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end, vm_flags_t newflags)
{
- vma->vm_flags &= VM_LOCKED_CLEAR_MASK;
+ static const struct mm_walk_ops mlock_walk_ops = {
+ .pmd_entry = mlock_pte_range,
+ };
- while (start < end) {
- struct page *page;
- unsigned int page_mask = 0;
- unsigned long page_increm;
- struct pagevec pvec;
- struct zone *zone;
+ /*
+ * There is a slight chance that concurrent page migration,
+ * or page reclaim finding a page of this now-VM_LOCKED vma,
+ * will call mlock_vma_page() and raise page's mlock_count:
+ * double counting, leaving the page unevictable indefinitely.
+ * Communicate this danger to mlock_vma_page() with VM_IO,
+ * which is a VM_SPECIAL flag not allowed on VM_LOCKED vmas.
+ * mmap_lock is held in write mode here, so this weird
+ * combination should not be visible to other mmap_lock users;
+ * but WRITE_ONCE so rmap walkers must see VM_IO if VM_LOCKED.
+ */
+ if (newflags & VM_LOCKED)
+ newflags |= VM_IO;
+ WRITE_ONCE(vma->vm_flags, newflags);
- pagevec_init(&pvec);
- /*
- * Although FOLL_DUMP is intended for get_dump_page(),
- * it just so happens that its special treatment of the
- * ZERO_PAGE (returning an error instead of doing get_page)
- * suits munlock very well (and if somehow an abnormal page
- * has sneaked into the range, we won't oops here: great).
- */
- page = follow_page(vma, start, FOLL_GET | FOLL_DUMP);
-
- if (page && !IS_ERR(page)) {
- if (PageTransTail(page)) {
- VM_BUG_ON_PAGE(PageMlocked(page), page);
- put_page(page); /* follow_page_mask() */
- } else if (PageTransHuge(page)) {
- lock_page(page);
- /*
- * Any THP page found by follow_page_mask() may
- * have gotten split before reaching
- * munlock_vma_page(), so we need to compute
- * the page_mask here instead.
- */
- page_mask = munlock_vma_page(page);
- unlock_page(page);
- put_page(page); /* follow_page_mask() */
- } else {
- /*
- * Non-huge pages are handled in batches via
- * pagevec. The pin from follow_page_mask()
- * prevents them from collapsing by THP.
- */
- pagevec_add(&pvec, page);
- zone = page_zone(page);
-
- /*
- * Try to fill the rest of pagevec using fast
- * pte walk. This will also update start to
- * the next page to process. Then munlock the
- * pagevec.
- */
- start = __munlock_pagevec_fill(&pvec, vma,
- zone, start, end);
- __munlock_pagevec(&pvec, zone);
- goto next;
- }
- }
- page_increm = 1 + page_mask;
- start += page_increm * PAGE_SIZE;
-next:
- cond_resched();
+ lru_add_drain();
+ walk_page_range(vma->vm_mm, start, end, &mlock_walk_ops, NULL);
+ lru_add_drain();
+
+ if (newflags & VM_IO) {
+ newflags &= ~VM_IO;
+ WRITE_ONCE(vma->vm_flags, newflags);
}
}
@@ -500,10 +382,9 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
pgoff_t pgoff;
int nr_pages;
int ret = 0;
- int lock = !!(newflags & VM_LOCKED);
- vm_flags_t old_flags = vma->vm_flags;
+ vm_flags_t oldflags = vma->vm_flags;
- if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
+ if (newflags == oldflags || (oldflags & VM_SPECIAL) ||
is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) ||
vma_is_dax(vma) || vma_is_secretmem(vma))
/* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */
@@ -535,9 +416,9 @@ success:
* Keep track of amount of locked VM.
*/
nr_pages = (end - start) >> PAGE_SHIFT;
- if (!lock)
+ if (!(newflags & VM_LOCKED))
nr_pages = -nr_pages;
- else if (old_flags & VM_LOCKED)
+ else if (oldflags & VM_LOCKED)
nr_pages = 0;
mm->locked_vm += nr_pages;
@@ -547,11 +428,12 @@ success:
* set VM_LOCKED, populate_vma_page_range will bring it back.
*/
- if (lock)
+ if ((newflags & VM_LOCKED) && (oldflags & VM_LOCKED)) {
+ /* No work to do, and mlocking twice would be wrong */
vma->vm_flags = newflags;
- else
- munlock_vma_pages_range(vma, start, end);
-
+ } else {
+ mlock_vma_pages_range(vma, start, end, newflags);
+ }
out:
*prev = vma;
return ret;
@@ -645,6 +527,18 @@ static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm,
return count >> PAGE_SHIFT;
}
+/*
+ * convert get_user_pages() return value to posix mlock() error
+ */
+static int __mlock_posix_error_return(long retval)
+{
+ if (retval == -EFAULT)
+ retval = -ENOMEM;
+ else if (retval == -ENOMEM)
+ retval = -EAGAIN;
+ return retval;
+}
+
static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags)
{
unsigned long locked;
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-22 10:23:27 +0300