virtiofs: add DAX mmap support (2a9a609a) · Commits · 戴 / test

fs/fuse/dax.c

+59 −0

Original line number	Diff line number	Diff line
		@@ -575,6 +575,65 @@ out:
		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;

+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,