Commit 3b93f911 authored by Al Viro's avatar Al Viro
Browse files

export generic_perform_write(), start getting rid of generic_file_buffer_write() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 5cb6c6c7

include/linux/fs.h

+2 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ struct cred; 
struct swap_info_struct;

struct seq_file;

struct workqueue_struct;

struct iov_iter;



extern void __init inode_init(void);

extern void __init inode_init_early(void);
@@ -2396,6 +2397,7 @@ extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, un 
extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);

extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,

		unsigned long *, loff_t, size_t, size_t);

extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);

extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,

		unsigned long, loff_t, size_t, ssize_t);

extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);

mm/filemap.c

+21 −16
Original line number Diff line number Diff line
@@ -2092,7 +2092,7 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping, 
}

EXPORT_SYMBOL(grab_cache_page_write_begin);



static ssize_t generic_perform_write(struct file *file,

ssize_t generic_perform_write(struct file *file,

				struct iov_iter *i, loff_t pos)

{

	struct address_space *mapping = file->f_mapping;
@@ -2180,6 +2180,7 @@ static ssize_t generic_perform_write(struct file *file, 


	return written ? written : status;

}

EXPORT_SYMBOL(generic_perform_write);



ssize_t

generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
@@ -2230,8 +2231,10 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 
	size_t count;		/* after file limit checks */

	struct inode 	*inode = mapping->host;

	loff_t		pos = iocb->ki_pos;

	ssize_t		written;

	ssize_t		written = 0;

	ssize_t		err;

	ssize_t		status;

	struct iov_iter from;



	ocount = 0;

	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
@@ -2242,8 +2245,6 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 


	/* We can write back this queue in page reclaim */

	current->backing_dev_info = mapping->backing_dev_info;

	written = 0;



	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));

	if (err)

		goto out;
@@ -2259,44 +2260,47 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 
	if (err)

		goto out;



	iov_iter_init(&from, iov, nr_segs, count, 0);



	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */

	if (unlikely(file->f_flags & O_DIRECT)) {

		loff_t endbyte;

		ssize_t written_buffered;



		written = generic_file_direct_write(iocb, iov, &nr_segs, pos,

		written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos,

							count, ocount);

		if (written < 0 || written == count)

			goto out;

		iov_iter_advance(&from, written);



		/*

		 * direct-io write to a hole: fall through to buffered I/O

		 * for completing the rest of the request.

		 */

		pos += written;

		count -= written;

		written_buffered = generic_file_buffered_write(iocb, iov,

						nr_segs, pos, count, written);



		status = generic_perform_write(file, &from, pos);

		/*

		 * If generic_file_buffered_write() retuned a synchronous error

		 * If generic_perform_write() returned a synchronous error

		 * then we want to return the number of bytes which were

		 * direct-written, or the error code if that was zero.  Note

		 * that this differs from normal direct-io semantics, which

		 * will return -EFOO even if some bytes were written.

		 */

		if (written_buffered < 0) {

			err = written_buffered;

		if (unlikely(status < 0) && !written) {

			err = status;

			goto out;

		}



		iocb->ki_pos = pos + status;

		/*

		 * We need to ensure that the page cache pages are written to

		 * disk and invalidated to preserve the expected O_DIRECT

		 * semantics.

		 */

		endbyte = pos + written_buffered - written - 1;

		endbyte = pos + status - 1;

		err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);

		if (err == 0) {

			written = written_buffered;

			written += status;

			invalidate_mapping_pages(mapping,

						 pos >> PAGE_CACHE_SHIFT,

						 endbyte >> PAGE_CACHE_SHIFT);
@@ -2307,8 +2311,9 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 
			 */

		}

	} else {

		written = generic_file_buffered_write(iocb, iov, nr_segs,

				pos, count, written);

		written = generic_perform_write(file, &from, pos);

		if (likely(written >= 0))

			iocb->ki_pos = pos + written;

	}

out:

	current->backing_dev_info = NULL;