[linux-block.git] / mm / page_vma_mapped.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/mm.h>
#include <linux/rmap.h>
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <linux/swapops.h>

#include "internal.h"

static inline bool not_found(struct page_vma_mapped_walk *pvmw)
{
	page_vma_mapped_walk_done(pvmw);
	return false;
}

static bool map_pte(struct page_vma_mapped_walk *pvmw)
{
	pvmw->pte = pte_offset_map(pvmw->pmd, pvmw->address);
	if (!(pvmw->flags & PVMW_SYNC)) {
		if (pvmw->flags & PVMW_MIGRATION) {
			if (!is_swap_pte(*pvmw->pte))
				return false;
		} else {
			/*
			 * We get here when we are trying to unmap a private
			 * device page from the process address space. Such
			 * page is not CPU accessible and thus is mapped as
			 * a special swap entry, nonetheless it still does
			 * count as a valid regular mapping for the page (and
			 * is accounted as such in page maps count).
			 *
			 * So handle this special case as if it was a normal
			 * page mapping ie lock CPU page table and returns
			 * true.
			 *
			 * For more details on device private memory see HMM
			 * (include/linux/hmm.h or mm/hmm.c).
			 */
			if (is_swap_pte(*pvmw->pte)) {
				swp_entry_t entry;

				/* Handle un-addressable ZONE_DEVICE memory */
				entry = pte_to_swp_entry(*pvmw->pte);
				if (!is_device_private_entry(entry) &&
				    !is_device_exclusive_entry(entry))
					return false;
			} else if (!pte_present(*pvmw->pte))
				return false;
		}
	}
	pvmw->ptl = pte_lockptr(pvmw->vma->vm_mm, pvmw->pmd);
	spin_lock(pvmw->ptl);
	return true;
}

/**
 * check_pte - check if @pvmw->page is mapped at the @pvmw->pte
 * @pvmw: page_vma_mapped_walk struct, includes a pair pte and page for checking
 *
 * page_vma_mapped_walk() found a place where @pvmw->page is *potentially*
 * mapped. check_pte() has to validate this.
 *
 * pvmw->pte may point to empty PTE, swap PTE or PTE pointing to
 * arbitrary page.
 *
 * If PVMW_MIGRATION flag is set, returns true if @pvmw->pte contains migration
 * entry that points to @pvmw->page or any subpage in case of THP.
 *
 * If PVMW_MIGRATION flag is not set, returns true if pvmw->pte points to
 * pvmw->page or any subpage in case of THP.
 *
 * Otherwise, return false.
 *
 */
static bool check_pte(struct page_vma_mapped_walk *pvmw)
{
	unsigned long pfn;

	if (pvmw->flags & PVMW_MIGRATION) {
		swp_entry_t entry;
		if (!is_swap_pte(*pvmw->pte))
			return false;
		entry = pte_to_swp_entry(*pvmw->pte);

		if (!is_migration_entry(entry) &&
		    !is_device_exclusive_entry(entry))
			return false;

		pfn = swp_offset_pfn(entry);
	} else if (is_swap_pte(*pvmw->pte)) {
		swp_entry_t entry;

		/* Handle un-addressable ZONE_DEVICE memory */
		entry = pte_to_swp_entry(*pvmw->pte);
		if (!is_device_private_entry(entry) &&
		    !is_device_exclusive_entry(entry))
			return false;

		pfn = swp_offset_pfn(entry);
	} else {
		if (!pte_present(*pvmw->pte))
			return false;

		pfn = pte_pfn(*pvmw->pte);
	}

	return (pfn - pvmw->pfn) < pvmw->nr_pages;
}

/* Returns true if the two ranges overlap.  Careful to not overflow. */
static bool check_pmd(unsigned long pfn, struct page_vma_mapped_walk *pvmw)
{
	if ((pfn + HPAGE_PMD_NR - 1) < pvmw->pfn)
		return false;
	if (pfn > pvmw->pfn + pvmw->nr_pages - 1)
		return false;
	return true;
}

static void step_forward(struct page_vma_mapped_walk *pvmw, unsigned long size)
{
	pvmw->address = (pvmw->address + size) & ~(size - 1);
	if (!pvmw->address)
		pvmw->address = ULONG_MAX;
}

/**
 * page_vma_mapped_walk - check if @pvmw->pfn is mapped in @pvmw->vma at
 * @pvmw->address
 * @pvmw: pointer to struct page_vma_mapped_walk. page, vma, address and flags
 * must be set. pmd, pte and ptl must be NULL.
 *
 * Returns true if the page is mapped in the vma. @pvmw->pmd and @pvmw->pte point
 * to relevant page table entries. @pvmw->ptl is locked. @pvmw->address is
 * adjusted if needed (for PTE-mapped THPs).
 *
 * If @pvmw->pmd is set but @pvmw->pte is not, you have found PMD-mapped page
 * (usually THP). For PTE-mapped THP, you should run page_vma_mapped_walk() in
 * a loop to find all PTEs that map the THP.
 *
 * For HugeTLB pages, @pvmw->pte is set to the relevant page table entry
 * regardless of which page table level the page is mapped at. @pvmw->pmd is
 * NULL.
 *
 * Returns false if there are no more page table entries for the page in
 * the vma. @pvmw->ptl is unlocked and @pvmw->pte is unmapped.
 *
 * If you need to stop the walk before page_vma_mapped_walk() returned false,
 * use page_vma_mapped_walk_done(). It will do the housekeeping.
 */
bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
{
	struct vm_area_struct *vma = pvmw->vma;
	struct mm_struct *mm = vma->vm_mm;
	unsigned long end;
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t pmde;

	/* The only possible pmd mapping has been handled on last iteration */
	if (pvmw->pmd && !pvmw->pte)
		return not_found(pvmw);

	if (unlikely(is_vm_hugetlb_page(vma))) {
		struct hstate *hstate = hstate_vma(vma);
		unsigned long size = huge_page_size(hstate);
		/* The only possible mapping was handled on last iteration */
		if (pvmw->pte)
			return not_found(pvmw);
		/*
		 * All callers that get here will already hold the
		 * i_mmap_rwsem.  Therefore, no additional locks need to be
		 * taken before calling hugetlb_walk().
		 */
		pvmw->pte = hugetlb_walk(vma, pvmw->address, size);
		if (!pvmw->pte)
			return false;

		pvmw->ptl = huge_pte_lock(hstate, mm, pvmw->pte);
		if (!check_pte(pvmw))
			return not_found(pvmw);
		return true;
	}

	end = vma_address_end(pvmw);
	if (pvmw->pte)
		goto next_pte;
restart:
	do {
		pgd = pgd_offset(mm, pvmw->address);
		if (!pgd_present(*pgd)) {
			step_forward(pvmw, PGDIR_SIZE);
			continue;
		}
		p4d = p4d_offset(pgd, pvmw->address);
		if (!p4d_present(*p4d)) {
			step_forward(pvmw, P4D_SIZE);
			continue;
		}
		pud = pud_offset(p4d, pvmw->address);
		if (!pud_present(*pud)) {
			step_forward(pvmw, PUD_SIZE);
			continue;
		}

		pvmw->pmd = pmd_offset(pud, pvmw->address);
		/*
		 * Make sure the pmd value isn't cached in a register by the
		 * compiler and used as a stale value after we've observed a
		 * subsequent update.
		 */
		pmde = READ_ONCE(*pvmw->pmd);

		if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde) ||
		    (pmd_present(pmde) && pmd_devmap(pmde))) {
			pvmw->ptl = pmd_lock(mm, pvmw->pmd);
			pmde = *pvmw->pmd;
			if (!pmd_present(pmde)) {
				swp_entry_t entry;

				if (!thp_migration_supported() ||
				    !(pvmw->flags & PVMW_MIGRATION))
					return not_found(pvmw);
				entry = pmd_to_swp_entry(pmde);
				if (!is_migration_entry(entry) ||
				    !check_pmd(swp_offset_pfn(entry), pvmw))
					return not_found(pvmw);
				return true;
			}
			if (likely(pmd_trans_huge(pmde) || pmd_devmap(pmde))) {
				if (pvmw->flags & PVMW_MIGRATION)
					return not_found(pvmw);
				if (!check_pmd(pmd_pfn(pmde), pvmw))
					return not_found(pvmw);
				return true;
			}
			/* THP pmd was split under us: handle on pte level */
			spin_unlock(pvmw->ptl);
			pvmw->ptl = NULL;
		} else if (!pmd_present(pmde)) {
			/*
			 * If PVMW_SYNC, take and drop THP pmd lock so that we
			 * cannot return prematurely, while zap_huge_pmd() has
			 * cleared *pmd but not decremented compound_mapcount().
			 */
			if ((pvmw->flags & PVMW_SYNC) &&
			    transhuge_vma_suitable(vma, pvmw->address) &&
			    (pvmw->nr_pages >= HPAGE_PMD_NR)) {
				spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);

				spin_unlock(ptl);
			}
			step_forward(pvmw, PMD_SIZE);
			continue;
		}
		if (!map_pte(pvmw))
			goto next_pte;
this_pte:
		if (check_pte(pvmw))
			return true;
next_pte:
		do {
			pvmw->address += PAGE_SIZE;
			if (pvmw->address >= end)
				return not_found(pvmw);
			/* Did we cross page table boundary? */
			if ((pvmw->address & (PMD_SIZE - PAGE_SIZE)) == 0) {
				if (pvmw->ptl) {
					spin_unlock(pvmw->ptl);
					pvmw->ptl = NULL;
				}
				pte_unmap(pvmw->pte);
				pvmw->pte = NULL;
				goto restart;
			}
			pvmw->pte++;
			if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) {
				pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
				spin_lock(pvmw->ptl);
			}
		} while (pte_none(*pvmw->pte));

		if (!pvmw->ptl) {
			pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
			spin_lock(pvmw->ptl);
		}
		goto this_pte;
	} while (pvmw->address < end);

	return false;
}

/**
 * page_mapped_in_vma - check whether a page is really mapped in a VMA
 * @page: the page to test
 * @vma: the VMA to test
 *
 * Returns 1 if the page is mapped into the page tables of the VMA, 0
 * if the page is not mapped into the page tables of this VMA.  Only
 * valid for normal file or anonymous VMAs.
 */
int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
{
	struct page_vma_mapped_walk pvmw = {
		.pfn = page_to_pfn(page),
		.nr_pages = 1,
		.vma = vma,
		.flags = PVMW_SYNC,
	};

	pvmw.address = vma_address(page, vma);
	if (pvmw.address == -EFAULT)
		return 0;
	if (!page_vma_mapped_walk(&pvmw))
		return 0;
	page_vma_mapped_walk_done(&pvmw);
	return 1;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
ace71a19 KS	2	#include <linux/mm.h>
	3	#include <linux/rmap.h>
	4	#include <linux/hugetlb.h>
	5	#include <linux/swap.h>
	6	#include <linux/swapops.h>
	7
	8	#include "internal.h"
	9
ace71a19 KS	10	static inline bool not_found(struct page_vma_mapped_walk *pvmw)
	11	{
	12	page_vma_mapped_walk_done(pvmw);
	13	return false;
	14	}
	15
	16	static bool map_pte(struct page_vma_mapped_walk *pvmw)
	17	{
	18	pvmw->pte = pte_offset_map(pvmw->pmd, pvmw->address);
	19	if (!(pvmw->flags & PVMW_SYNC)) {
	20	if (pvmw->flags & PVMW_MIGRATION) {
	21	if (!is_swap_pte(*pvmw->pte))
	22	return false;
	23	} else {
aab8d052 RC	24	/*
	25	* We get here when we are trying to unmap a private
	26	* device page from the process address space. Such
	27	* page is not CPU accessible and thus is mapped as
	28	* a special swap entry, nonetheless it still does
	29	* count as a valid regular mapping for the page (and
	30	* is accounted as such in page maps count).
	31	*
	32	* So handle this special case as if it was a normal
	33	* page mapping ie lock CPU page table and returns
	34	* true.
	35	*
	36	* For more details on device private memory see HMM
	37	* (include/linux/hmm.h or mm/hmm.c).
	38	*/
	39	if (is_swap_pte(*pvmw->pte)) {
	40	swp_entry_t entry;
	41
	42	/* Handle un-addressable ZONE_DEVICE memory */
	43	entry = pte_to_swp_entry(*pvmw->pte);
b756a3b5 AP	44	if (!is_device_private_entry(entry) &&
b756a3b5 AP	45	!is_device_exclusive_entry(entry))
aab8d052 RC	46	return false;
aab8d052 RC	47	} else if (!pte_present(*pvmw->pte))
ace71a19 KS	48	return false;
	49	}
	50	}
	51	pvmw->ptl = pte_lockptr(pvmw->vma->vm_mm, pvmw->pmd);
	52	spin_lock(pvmw->ptl);
	53	return true;
	54	}
	55
0d665e7b KS	56	/**
0d665e7b KS	57	* check_pte - check if @pvmw->page is mapped at the @pvmw->pte
777f303c	58	* @pvmw: page_vma_mapped_walk struct, includes a pair pte and page for checking
0d665e7b KS	59	*
	60	* page_vma_mapped_walk() found a place where @pvmw->page is potentially
	61	* mapped. check_pte() has to validate this.
	62	*
777f303c AS	63	* pvmw->pte may point to empty PTE, swap PTE or PTE pointing to
777f303c AS	64	* arbitrary page.
0d665e7b KS	65	*
	66	* If PVMW_MIGRATION flag is set, returns true if @pvmw->pte contains migration
	67	* entry that points to @pvmw->page or any subpage in case of THP.
	68	*
777f303c AS	69	* If PVMW_MIGRATION flag is not set, returns true if pvmw->pte points to
777f303c AS	70	* pvmw->page or any subpage in case of THP.
0d665e7b KS	71	*
	72	* Otherwise, return false.
	73	*
	74	*/
ace71a19 KS	75	static bool check_pte(struct page_vma_mapped_walk *pvmw)
ace71a19 KS	76	{
0d665e7b KS	77	unsigned long pfn;
0d665e7b KS	78
ace71a19	79	if (pvmw->flags & PVMW_MIGRATION) {
ace71a19 KS	80	swp_entry_t entry;
	81	if (!is_swap_pte(*pvmw->pte))
	82	return false;
	83	entry = pte_to_swp_entry(*pvmw->pte);
a5430dda	84
b756a3b5 AP	85	if (!is_migration_entry(entry) &&
b756a3b5 AP	86	!is_device_exclusive_entry(entry))
ace71a19	87	return false;
a5430dda	88
0d206b5d	89	pfn = swp_offset_pfn(entry);
0d665e7b KS	90	} else if (is_swap_pte(*pvmw->pte)) {
0d665e7b KS	91	swp_entry_t entry;
a5430dda	92
0d665e7b KS	93	/* Handle un-addressable ZONE_DEVICE memory */
0d665e7b KS	94	entry = pte_to_swp_entry(*pvmw->pte);
b756a3b5 AP	95	if (!is_device_private_entry(entry) &&
b756a3b5 AP	96	!is_device_exclusive_entry(entry))
ace71a19 KS	97	return false;
ace71a19 KS	98
0d206b5d	99	pfn = swp_offset_pfn(entry);
0d665e7b KS	100	} else {
0d665e7b KS	101	if (!pte_present(*pvmw->pte))
ace71a19	102	return false;
0d665e7b KS	103
0d665e7b KS	104	pfn = pte_pfn(*pvmw->pte);
ace71a19 KS	105	}
ace71a19 KS	106
2aff7a47 MWO	107	return (pfn - pvmw->pfn) < pvmw->nr_pages;
	108	}
	109
	110	/* Returns true if the two ranges overlap. Careful to not overflow. */
	111	static bool check_pmd(unsigned long pfn, struct page_vma_mapped_walk *pvmw)
	112	{
	113	if ((pfn + HPAGE_PMD_NR - 1) < pvmw->pfn)
	114	return false;
	115	if (pfn > pvmw->pfn + pvmw->nr_pages - 1)
	116	return false;
	117	return true;
ace71a19 KS	118	}
ace71a19 KS	119
a9a7504d HD	120	static void step_forward(struct page_vma_mapped_walk *pvmw, unsigned long size)
	121	{
	122	pvmw->address = (pvmw->address + size) & ~(size - 1);
	123	if (!pvmw->address)
	124	pvmw->address = ULONG_MAX;
	125	}
	126
ace71a19	127	/**
2aff7a47	128	* page_vma_mapped_walk - check if @pvmw->pfn is mapped in @pvmw->vma at
ace71a19 KS	129	* @pvmw->address
	130	* @pvmw: pointer to struct page_vma_mapped_walk. page, vma, address and flags
	131	* must be set. pmd, pte and ptl must be NULL.
	132	*
	133	* Returns true if the page is mapped in the vma. @pvmw->pmd and @pvmw->pte point
	134	* to relevant page table entries. @pvmw->ptl is locked. @pvmw->address is
	135	* adjusted if needed (for PTE-mapped THPs).
	136	*
	137	* If @pvmw->pmd is set but @pvmw->pte is not, you have found PMD-mapped page
	138	* (usually THP). For PTE-mapped THP, you should run page_vma_mapped_walk() in
	139	* a loop to find all PTEs that map the THP.
	140	*
	141	* For HugeTLB pages, @pvmw->pte is set to the relevant page table entry
	142	* regardless of which page table level the page is mapped at. @pvmw->pmd is
	143	* NULL.
	144	*
baf2f90b	145	* Returns false if there are no more page table entries for the page in
ace71a19 KS	146	* the vma. @pvmw->ptl is unlocked and @pvmw->pte is unmapped.
	147	*
	148	* If you need to stop the walk before page_vma_mapped_walk() returned false,
	149	* use page_vma_mapped_walk_done(). It will do the housekeeping.
	150	*/
	151	bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
	152	{
2aff7a47 MWO	153	struct vm_area_struct *vma = pvmw->vma;
2aff7a47 MWO	154	struct mm_struct *mm = vma->vm_mm;
47446630	155	unsigned long end;
ace71a19	156	pgd_t *pgd;
c2febafc	157	p4d_t *p4d;
ace71a19	158	pud_t *pud;
a7b10095	159	pmd_t pmde;
ace71a19 KS	160
	161	/* The only possible pmd mapping has been handled on last iteration */
	162	if (pvmw->pmd && !pvmw->pte)
	163	return not_found(pvmw);
	164
2aff7a47	165	if (unlikely(is_vm_hugetlb_page(vma))) {
98ea0259	166	struct hstate *hstate = hstate_vma(vma);
98ea0259	167	unsigned long size = huge_page_size(hstate);
6d0fd598 HD	168	/* The only possible mapping was handled on last iteration */
	169	if (pvmw->pte)
	170	return not_found(pvmw);
9c67a207 PX	171	/*
	172	* All callers that get here will already hold the
	173	* i_mmap_rwsem. Therefore, no additional locks need to be
	174	* taken before calling hugetlb_walk().
	175	*/
	176	pvmw->pte = hugetlb_walk(vma, pvmw->address, size);
ace71a19 KS	177	if (!pvmw->pte)
	178	return false;
	179
8f0b747d	180	pvmw->ptl = huge_pte_lock(hstate, mm, pvmw->pte);
ace71a19 KS	181	if (!check_pte(pvmw))
	182	return not_found(pvmw);
	183	return true;
	184	}
6d0fd598	185
2aff7a47	186	end = vma_address_end(pvmw);
6d0fd598 HD	187	if (pvmw->pte)
6d0fd598 HD	188	goto next_pte;
ace71a19	189	restart:
a9a7504d	190	do {
b3807a91	191	pgd = pgd_offset(mm, pvmw->address);
a9a7504d HD	192	if (!pgd_present(*pgd)) {
	193	step_forward(pvmw, PGDIR_SIZE);
	194	continue;
	195	}
b3807a91	196	p4d = p4d_offset(pgd, pvmw->address);
a9a7504d HD	197	if (!p4d_present(*p4d)) {
	198	step_forward(pvmw, P4D_SIZE);
	199	continue;
	200	}
b3807a91	201	pud = pud_offset(p4d, pvmw->address);
a9a7504d HD	202	if (!pud_present(*pud)) {
	203	step_forward(pvmw, PUD_SIZE);
	204	continue;
	205	}
e2e1d407	206
b3807a91	207	pvmw->pmd = pmd_offset(pud, pvmw->address);
732ed558	208	/*
b3807a91 HD	209	* Make sure the pmd value isn't cached in a register by the
	210	* compiler and used as a stale value after we've observed a
	211	* subsequent update.
732ed558	212	*/
b3807a91 HD	213	pmde = READ_ONCE(*pvmw->pmd);
b3807a91 HD	214
6472f6d2 MS	215	if (pmd_trans_huge(pmde) \|\| is_pmd_migration_entry(pmde) \|\|
6472f6d2 MS	216	(pmd_present(pmde) && pmd_devmap(pmde))) {
b3807a91 HD	217	pvmw->ptl = pmd_lock(mm, pvmw->pmd);
b3807a91 HD	218	pmde = *pvmw->pmd;
b3807a91 HD	219	if (!pmd_present(pmde)) {
	220	swp_entry_t entry;
	221
	222	if (!thp_migration_supported() \|\|
	223	!(pvmw->flags & PVMW_MIGRATION))
	224	return not_found(pvmw);
	225	entry = pmd_to_swp_entry(pmde);
	226	if (!is_migration_entry(entry) \|\|
0d206b5d	227	!check_pmd(swp_offset_pfn(entry), pvmw))
b3807a91 HD	228	return not_found(pvmw);
	229	return true;
	230	}
6472f6d2 MS	231	if (likely(pmd_trans_huge(pmde) \|\| pmd_devmap(pmde))) {
	232	if (pvmw->flags & PVMW_MIGRATION)
	233	return not_found(pvmw);
	234	if (!check_pmd(pmd_pfn(pmde), pvmw))
	235	return not_found(pvmw);
	236	return true;
	237	}
b3807a91 HD	238	/* THP pmd was split under us: handle on pte level */
	239	spin_unlock(pvmw->ptl);
	240	pvmw->ptl = NULL;
	241	} else if (!pmd_present(pmde)) {
	242	/*
	243	* If PVMW_SYNC, take and drop THP pmd lock so that we
	244	* cannot return prematurely, while zap_huge_pmd() has
	245	* cleared *pmd but not decremented compound_mapcount().
	246	*/
	247	if ((pvmw->flags & PVMW_SYNC) &&
c453d8c7	248	transhuge_vma_suitable(vma, pvmw->address) &&
2aff7a47	249	(pvmw->nr_pages >= HPAGE_PMD_NR)) {
b3807a91	250	spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);
732ed558	251
b3807a91 HD	252	spin_unlock(ptl);
b3807a91 HD	253	}
a9a7504d HD	254	step_forward(pvmw, PMD_SIZE);
a9a7504d HD	255	continue;
732ed558	256	}
b3807a91 HD	257	if (!map_pte(pvmw))
b3807a91 HD	258	goto next_pte;
47446630	259	this_pte:
ace71a19 KS	260	if (check_pte(pvmw))
ace71a19 KS	261	return true;
d75450ff	262	next_pte:
d75450ff	263	do {
ace71a19	264	pvmw->address += PAGE_SIZE;
494334e4	265	if (pvmw->address >= end)
ace71a19 KS	266	return not_found(pvmw);
ace71a19 KS	267	/* Did we cross page table boundary? */
44828248	268	if ((pvmw->address & (PMD_SIZE - PAGE_SIZE)) == 0) {
ace71a19 KS	269	if (pvmw->ptl) {
	270	spin_unlock(pvmw->ptl);
	271	pvmw->ptl = NULL;
	272	}
44828248 HD	273	pte_unmap(pvmw->pte);
44828248 HD	274	pvmw->pte = NULL;
ace71a19	275	goto restart;
ace71a19	276	}
44828248	277	pvmw->pte++;
a7a69d8b HD	278	if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) {
	279	pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
	280	spin_lock(pvmw->ptl);
	281	}
ace71a19 KS	282	} while (pte_none(*pvmw->pte));
	283
	284	if (!pvmw->ptl) {
	285	pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
	286	spin_lock(pvmw->ptl);
	287	}
47446630	288	goto this_pte;
a9a7504d HD	289	} while (pvmw->address < end);
	290
	291	return false;
ace71a19	292	}
6a328a62 KS	293
	294	/**
	295	* page_mapped_in_vma - check whether a page is really mapped in a VMA
	296	* @page: the page to test
	297	* @vma: the VMA to test
	298	*
	299	* Returns 1 if the page is mapped into the page tables of the VMA, 0
	300	* if the page is not mapped into the page tables of this VMA. Only
	301	* valid for normal file or anonymous VMAs.
	302	*/
	303	int page_mapped_in_vma(struct page page, struct vm_area_struct vma)
	304	{
	305	struct page_vma_mapped_walk pvmw = {
2aff7a47 MWO	306	.pfn = page_to_pfn(page),
2aff7a47 MWO	307	.nr_pages = 1,
6a328a62 KS	308	.vma = vma,
	309	.flags = PVMW_SYNC,
	310	};
6a328a62	311
494334e4 HD	312	pvmw.address = vma_address(page, vma);
494334e4 HD	313	if (pvmw.address == -EFAULT)
6a328a62	314	return 0;
6a328a62 KS	315	if (!page_vma_mapped_walk(&pvmw))
	316	return 0;
	317	page_vma_mapped_walk_done(&pvmw);
	318	return 1;
	319	}