fs/9p: Add direct IO support in cached mode (e959b549) · Commits · e / devices / android_kernel_fairphone_FP3

fs/9p/vfs_addr.c

+3 −2

Original line number	Original line	Diff line number	Diff line
	@@ -254,7 +254,8 @@ static int v9fs_launder_page(struct page *page)
	* with an error.		* with an error.
	*		*
	*/		*/
	ssize_t v9fs_direct_IO(int rw, struct kiocb iocb, const struct iovec iov,		static ssize_t
			v9fs_direct_IO(int rw, struct kiocb iocb, const struct iovec iov,
	loff_t pos, unsigned long nr_segs)		loff_t pos, unsigned long nr_segs)
	{		{
	/*		/*

fs/9p/vfs_file.c

+113 −4

Original line number	Original line	Diff line number	Diff line
	@@ -579,15 +579,124 @@ v9fs_vm_page_mkwrite(struct vm_area_struct vma, struct vm_fault vmf)
	return VM_FAULT_NOPAGE;		return VM_FAULT_NOPAGE;
	}		}

			static ssize_t
			v9fs_direct_read(struct file filp, char __user udata, size_t count,
			loff_t *offsetp)
			{
			loff_t size, offset;
			struct inode *inode;
			struct address_space *mapping;

			offset = *offsetp;
			mapping = filp->f_mapping;
			inode = mapping->host;
			if (!count)
			return 0;
			size = i_size_read(inode);
			if (offset < size)
			filemap_write_and_wait_range(mapping, offset,
			offset + count - 1);

			return v9fs_file_read(filp, udata, count, offsetp);
			}

			/**
			* v9fs_cached_file_read - read from a file
			* @filp: file pointer to read
			* @udata: user data buffer to read data into
			* @count: size of buffer
			* @offset: offset at which to read data
			*
			*/
			static ssize_t
			v9fs_cached_file_read(struct file filp, char __user data, size_t count,
			loff_t *offset)
			{
			if (filp->f_flags & O_DIRECT)
			return v9fs_direct_read(filp, data, count, offset);
			return do_sync_read(filp, data, count, offset);
			}

			static ssize_t
			v9fs_direct_write(struct file filp, const char __user data,
			size_t count, loff_t *offsetp)
			{
			loff_t offset;
			ssize_t retval;
			struct inode *inode;
			struct address_space *mapping;

			offset = *offsetp;
			mapping = filp->f_mapping;
			inode = mapping->host;
			if (!count)
			return 0;

			mutex_lock(&inode->i_mutex);
			retval = filemap_write_and_wait_range(mapping, offset,
			offset + count - 1);
			if (retval)
			goto err_out;
			/*
			* After a write we want buffered reads to be sure to go to disk to get
			* the new data. We invalidate clean cached page from the region we're
			* about to write. We do this before the write so that if we fail
			* here we fall back to buffered write
			*/
			if (mapping->nrpages) {
			pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
			pgoff_t pg_end = (offset + count - 1) >> PAGE_CACHE_SHIFT;

			retval = invalidate_inode_pages2_range(mapping,
			pg_start, pg_end);
			/*
			* If a page can not be invalidated, fall back
			* to buffered write.
			*/
			if (retval) {
			if (retval == -EBUSY)
			goto buff_write;
			goto err_out;
			}
			}
			retval = v9fs_file_write(filp, data, count, offsetp);
			err_out:
			mutex_unlock(&inode->i_mutex);
			return retval;

			buff_write:
			mutex_unlock(&inode->i_mutex);
			return do_sync_write(filp, data, count, offsetp);
			}

			/**
			* v9fs_cached_file_write - write to a file
			* @filp: file pointer to write
			* @data: data buffer to write data from
			* @count: size of buffer
			* @offset: offset at which to write data
			*
			*/
			static ssize_t
			v9fs_cached_file_write(struct file filp, const char __user data,
			size_t count, loff_t *offset)
			{

			if (filp->f_flags & O_DIRECT)
			return v9fs_direct_write(filp, data, count, offset);
			return do_sync_write(filp, data, count, offset);
			}

	static const struct vm_operations_struct v9fs_file_vm_ops = {		static const struct vm_operations_struct v9fs_file_vm_ops = {
	.fault = filemap_fault,		.fault = filemap_fault,
	.page_mkwrite = v9fs_vm_page_mkwrite,		.page_mkwrite = v9fs_vm_page_mkwrite,
	};		};


	const struct file_operations v9fs_cached_file_operations = {		const struct file_operations v9fs_cached_file_operations = {
	.llseek = generic_file_llseek,		.llseek = generic_file_llseek,
	.read = do_sync_read,		.read = v9fs_cached_file_read,
	.write = do_sync_write,		.write = v9fs_cached_file_write,
	.aio_read = generic_file_aio_read,		.aio_read = generic_file_aio_read,
	.aio_write = generic_file_aio_write,		.aio_write = generic_file_aio_write,
	.open = v9fs_file_open,		.open = v9fs_file_open,
	@@ -599,8 +708,8 @@ const struct file_operations v9fs_cached_file_operations = {

	const struct file_operations v9fs_cached_file_operations_dotl = {		const struct file_operations v9fs_cached_file_operations_dotl = {
	.llseek = generic_file_llseek,		.llseek = generic_file_llseek,
	.read = do_sync_read,		.read = v9fs_cached_file_read,
	.write = do_sync_write,		.write = v9fs_cached_file_write,
	.aio_read = generic_file_aio_read,		.aio_read = generic_file_aio_read,
	.aio_write = generic_file_aio_write,		.aio_write = generic_file_aio_write,
	.open = v9fs_file_open,		.open = v9fs_file_open,