Commit 2a9a609a authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Miklos Szeredi
Browse files

virtiofs: add DAX mmap support 



Add DAX mmap() support.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent c2d0ad00

fs/fuse/dax.c

+59 −0
Original line number Diff line number Diff line
@@ -575,6 +575,65 @@ ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) 
	return ret;

}



static vm_fault_t __fuse_dax_fault(struct vm_fault *vmf,

				   enum page_entry_size pe_size, bool write)

{

	vm_fault_t ret;

	struct inode *inode = file_inode(vmf->vma->vm_file);

	struct super_block *sb = inode->i_sb;

	pfn_t pfn;



	if (write)

		sb_start_pagefault(sb);



	ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &fuse_iomap_ops);



	if (ret & VM_FAULT_NEEDDSYNC)

		ret = dax_finish_sync_fault(vmf, pe_size, pfn);



	if (write)

		sb_end_pagefault(sb);



	return ret;

}



static vm_fault_t fuse_dax_fault(struct vm_fault *vmf)

{

	return __fuse_dax_fault(vmf, PE_SIZE_PTE,

				vmf->flags & FAULT_FLAG_WRITE);

}



static vm_fault_t fuse_dax_huge_fault(struct vm_fault *vmf,

			       enum page_entry_size pe_size)

{

	return __fuse_dax_fault(vmf, pe_size, vmf->flags & FAULT_FLAG_WRITE);

}



static vm_fault_t fuse_dax_page_mkwrite(struct vm_fault *vmf)

{

	return __fuse_dax_fault(vmf, PE_SIZE_PTE, true);

}



static vm_fault_t fuse_dax_pfn_mkwrite(struct vm_fault *vmf)

{

	return __fuse_dax_fault(vmf, PE_SIZE_PTE, true);

}



static const struct vm_operations_struct fuse_dax_vm_ops = {

	.fault		= fuse_dax_fault,

	.huge_fault	= fuse_dax_huge_fault,

	.page_mkwrite	= fuse_dax_page_mkwrite,

	.pfn_mkwrite	= fuse_dax_pfn_mkwrite,

};



int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma)

{

	file_accessed(file);

	vma->vm_ops = &fuse_dax_vm_ops;

	vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;

	return 0;

}



static void fuse_free_dax_mem_ranges(struct list_head *mem_list)

{

	struct fuse_dax_mapping *range, *temp;

fs/fuse/file.c

+5 −0
Original line number Diff line number Diff line
@@ -2325,6 +2325,10 @@ static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) 
{

	struct fuse_file *ff = file->private_data;



	/* DAX mmap is superior to direct_io mmap */

	if (FUSE_IS_DAX(file_inode(file)))

		return fuse_dax_mmap(file, vma);



	if (ff->open_flags & FOPEN_DIRECT_IO) {

		/* Can't provide the coherency needed for MAP_SHARED */

		if (vma->vm_flags & VM_MAYSHARE)
@@ -3413,6 +3417,7 @@ static const struct file_operations fuse_file_operations = { 
	.release	= fuse_release,

	.fsync		= fuse_fsync,

	.lock		= fuse_file_lock,

	.get_unmapped_area = thp_get_unmapped_area,

	.flock		= fuse_file_flock,

	.splice_read	= generic_file_splice_read,

	.splice_write	= iter_file_splice_write,