From: Dan Williams <dan.j.williams@intel.com>
To: linux-nvdimm@lists.01.org
Cc: Jan Kara <jack@suse.cz>,
hch@lst.de, hch@lst.de, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org, jack@suse.cz,
ross.zwisler@linux.intel.com
Subject: [PATCH v5 02/11] device-dax: Enable page_mapping()
Date: Wed, 04 Jul 2018 14:40:34 -0700 [thread overview]
Message-ID: <153074043405.27838.13174871137034713893.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <153074042316.27838.17319837331947007626.stgit@dwillia2-desk3.amr.corp.intel.com>
In support of enabling memory_failure() handling for device-dax
mappings, set the ->mapping association of pages backing device-dax
mappings. The rmap implementation requires page_mapping() to return the
address_space hosting the vmas that map the page.
The ->mapping pointer is never cleared. There is no possibility for the
page to become associated with another address_space while the device is
enabled. When the device is disabled the 'struct page' array for the
device is destroyed / later reinitialized to zero.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dax/device.c | 55 +++++++++++++++++++++++++++++++++++---------------
1 file changed, 38 insertions(+), 17 deletions(-)
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index ad5e7b4a15dc..95cfcfd612df 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -245,12 +245,11 @@ __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
}
static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
- struct vm_fault *vmf)
+ struct vm_fault *vmf, pfn_t *pfn)
{
struct device *dev = &dev_dax->dev;
struct dax_region *dax_region;
phys_addr_t phys;
- pfn_t pfn;
unsigned int fault_size = PAGE_SIZE;
if (check_vma(dev_dax, vmf->vma, __func__))
@@ -272,20 +271,19 @@ static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
return VM_FAULT_SIGBUS;
}
- pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+ *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
- return vmf_insert_mixed(vmf->vma, vmf->address, pfn);
+ return vmf_insert_mixed(vmf->vma, vmf->address, *pfn);
}
static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
- struct vm_fault *vmf)
+ struct vm_fault *vmf, pfn_t *pfn)
{
unsigned long pmd_addr = vmf->address & PMD_MASK;
struct device *dev = &dev_dax->dev;
struct dax_region *dax_region;
phys_addr_t phys;
pgoff_t pgoff;
- pfn_t pfn;
unsigned int fault_size = PMD_SIZE;
if (check_vma(dev_dax, vmf->vma, __func__))
@@ -321,22 +319,21 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
return VM_FAULT_SIGBUS;
}
- pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+ *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
- return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, pfn,
+ return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, *pfn,
vmf->flags & FAULT_FLAG_WRITE);
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
- struct vm_fault *vmf)
+ struct vm_fault *vmf, pfn_t *pfn)
{
unsigned long pud_addr = vmf->address & PUD_MASK;
struct device *dev = &dev_dax->dev;
struct dax_region *dax_region;
phys_addr_t phys;
pgoff_t pgoff;
- pfn_t pfn;
unsigned int fault_size = PUD_SIZE;
@@ -373,14 +370,14 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
return VM_FAULT_SIGBUS;
}
- pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+ *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
- return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, pfn,
+ return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, *pfn,
vmf->flags & FAULT_FLAG_WRITE);
}
#else
static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
- struct vm_fault *vmf)
+ struct vm_fault *vmf, pfn_t *pfn)
{
return VM_FAULT_FALLBACK;
}
@@ -389,8 +386,10 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
enum page_entry_size pe_size)
{
- int rc, id;
struct file *filp = vmf->vma->vm_file;
+ unsigned long fault_size;
+ int rc, id;
+ pfn_t pfn;
struct dev_dax *dev_dax = filp->private_data;
dev_dbg(&dev_dax->dev, "%s: %s (%#lx - %#lx) size = %d\n", current->comm,
@@ -400,17 +399,39 @@ static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
id = dax_read_lock();
switch (pe_size) {
case PE_SIZE_PTE:
- rc = __dev_dax_pte_fault(dev_dax, vmf);
+ fault_size = PAGE_SIZE;
+ rc = __dev_dax_pte_fault(dev_dax, vmf, &pfn);
break;
case PE_SIZE_PMD:
- rc = __dev_dax_pmd_fault(dev_dax, vmf);
+ fault_size = PMD_SIZE;
+ rc = __dev_dax_pmd_fault(dev_dax, vmf, &pfn);
break;
case PE_SIZE_PUD:
- rc = __dev_dax_pud_fault(dev_dax, vmf);
+ fault_size = PUD_SIZE;
+ rc = __dev_dax_pud_fault(dev_dax, vmf, &pfn);
break;
default:
rc = VM_FAULT_SIGBUS;
}
+
+ if (rc == VM_FAULT_NOPAGE) {
+ unsigned long i;
+
+ /*
+ * In the device-dax case the only possibility for a
+ * VM_FAULT_NOPAGE result is when device-dax capacity is
+ * mapped. No need to consider the zero page, or racing
+ * conflicting mappings.
+ */
+ for (i = 0; i < fault_size / PAGE_SIZE; i++) {
+ struct page *page;
+
+ page = pfn_to_page(pfn_t_to_pfn(pfn) + i);
+ if (page->mapping)
+ continue;
+ page->mapping = filp->f_mapping;
+ }
+ }
dax_read_unlock(id);
return rc;
next prev parent reply other threads:[~2018-07-04 21:40 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-04 21:40 [PATCH v5 00/11] mm: Teach memory_failure() about ZONE_DEVICE pages Dan Williams
2018-07-04 21:40 ` [PATCH v5 01/11] device-dax: Convert to vmf_insert_mixed and vm_fault_t Dan Williams
2018-07-04 21:40 ` Dan Williams [this message]
2018-07-04 21:40 ` [PATCH v5 03/11] device-dax: Set page->index Dan Williams
2018-07-04 21:40 ` [PATCH v5 04/11] filesystem-dax: " Dan Williams
2018-07-04 21:40 ` [PATCH v5 05/11] mm, madvise_inject_error: Let memory_failure() optionally take a page reference Dan Williams
2018-07-13 6:31 ` Naoya Horiguchi
2018-07-14 0:34 ` Dan Williams
2018-07-04 21:40 ` [PATCH v5 06/11] mm, memory_failure: Collect mapping size in collect_procs() Dan Williams
2018-07-13 6:49 ` Naoya Horiguchi
2018-07-04 21:41 ` [PATCH v5 07/11] filesystem-dax: Introduce dax_lock_mapping_entry() Dan Williams
2018-07-05 1:07 ` kbuild test robot
2018-07-05 3:31 ` kbuild test robot
2018-07-05 3:33 ` [PATCH v6] " Dan Williams
2018-09-24 15:57 ` [PATCH v5 07/11] " Barret Rhoden
2018-09-27 11:13 ` Jan Kara
2018-07-04 21:41 ` [PATCH v5 08/11] mm, memory_failure: Teach memory_failure() about dev_pagemap pages Dan Williams
2018-07-13 8:52 ` Naoya Horiguchi
2018-07-14 0:28 ` Dan Williams
2018-07-17 6:36 ` Naoya Horiguchi
2018-07-04 21:41 ` [PATCH v5 09/11] x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses Dan Williams
2018-07-04 21:41 ` [PATCH v5 10/11] x86/memory_failure: Introduce {set, clear}_mce_nospec() Dan Williams
2018-07-04 21:41 ` [PATCH v5 11/11] libnvdimm, pmem: Restore page attributes when clearing errors Dan Williams
2018-07-13 4:44 ` [PATCH v5 00/11] mm: Teach memory_failure() about ZONE_DEVICE pages Dan Williams
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