[PATCH 09/10] ext4: Huge page fault support

From: Matthew Wilcox
Date: Fri Jul 10 2015 - 16:30:47 EST


From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>

Use DAX to provide support for huge pages.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
fs/ext4/file.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 34d814f..ca5302a 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -210,6 +210,13 @@ static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
return dax_fault(vma, vmf, ext4_get_block_write, ext4_end_io_unwritten);
}

+static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd, unsigned int flags)
+{
+ return dax_pmd_fault(vma, addr, pmd, flags, ext4_get_block_write,
+ ext4_end_io_unwritten);
+}
+
static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
return dax_mkwrite(vma, vmf, ext4_get_block_write,
@@ -218,6 +225,7 @@ static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)

static const struct vm_operations_struct ext4_dax_vm_ops = {
.fault = ext4_dax_fault,
+ .pmd_fault = ext4_dax_pmd_fault,
.page_mkwrite = ext4_dax_mkwrite,
.pfn_mkwrite = dax_pfn_mkwrite,
};
@@ -245,7 +253,7 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
file_accessed(file);
if (IS_DAX(file_inode(file))) {
vma->vm_ops = &ext4_dax_vm_ops;
- vma->vm_flags |= VM_MIXEDMAP;
+ vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
} else {
vma->vm_ops = &ext4_file_vm_ops;
}
--
2.1.4

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