Re: [PATCH v2 03/16] CIFS: Separate page sending from writepages

[Jeff Layton <jlayton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>]

On Fri, 27 Jun 2014 13:57:40 +0400
Pavel Shilovsky <pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org> wrote:

> Signed-off-by: Pavel Shilovsky <pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>
> ---
>  fs/cifs/file.c | 100 +++++++++++++++++++++++++++++++--------------------------
>  1 file changed, 54 insertions(+), 46 deletions(-)
> 
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 69d1763..306c3df 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -1958,6 +1958,58 @@ wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
>  	return nr_pages;
>  }
>  
> +static int
> +wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
> +		 struct address_space *mapping, struct writeback_control *wbc)
> +{
> +	int rc = 0;
> +	struct TCP_Server_Info *server;
> +	unsigned int i;
> +
> +	wdata->sync_mode = wbc->sync_mode;
> +	wdata->nr_pages = nr_pages;
> +	wdata->offset = page_offset(wdata->pages[0]);
> +	wdata->pagesz = PAGE_CACHE_SIZE;
> +	wdata->tailsz = min(i_size_read(mapping->host) -
> +			page_offset(wdata->pages[nr_pages - 1]),
> +			(loff_t)PAGE_CACHE_SIZE);
> +	wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
> +
> +	do {
> +		if (wdata->cfile != NULL)
> +			cifsFileInfo_put(wdata->cfile);
> +		wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
> +		if (!wdata->cfile) {
> +			cifs_dbg(VFS, "No writable handles for inode\n");
> +			rc = -EBADF;
> +			break;
> +		}
> +		wdata->pid = wdata->cfile->pid;
> +		server = tlink_tcon(wdata->cfile->tlink)->ses->server;
> +		rc = server->ops->async_writev(wdata, cifs_writedata_release);
> +	} while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
> +
> +	for (i = 0; i < nr_pages; ++i)
> +		unlock_page(wdata->pages[i]);
> +
> +	if (!rc)
> +		return rc;
> +
> +	/* send failure -- clean up the mess */
> +	for (i = 0; i < nr_pages; ++i) {
> +		if (rc == -EAGAIN)
> +			redirty_page_for_writepage(wbc, wdata->pages[i]);
> +		else
> +			SetPageError(wdata->pages[i]);
> +		end_page_writeback(wdata->pages[i]);
> +		page_cache_release(wdata->pages[i]);
> +	}
> +	if (rc != -EAGAIN)
> +		mapping_set_error(mapping, rc);
> +
> +	return rc;
> +}
> +
>  static int cifs_writepages(struct address_space *mapping,
>  			   struct writeback_control *wbc)
>  {
> @@ -1965,7 +2017,6 @@ static int cifs_writepages(struct address_space *mapping,
>  	bool done = false, scanned = false, range_whole = false;
>  	pgoff_t end, index;
>  	struct cifs_writedata *wdata;
> -	struct TCP_Server_Info *server;
>  	int rc = 0;
>  
>  	/*
> @@ -1987,7 +2038,7 @@ static int cifs_writepages(struct address_space *mapping,
>  	}
>  retry:
>  	while (!done && index <= end) {
> -		unsigned int i, nr_pages, found_pages;
> +		unsigned int nr_pages, found_pages;
>  		pgoff_t next = 0, tofind;
>  		struct page **pages;
>  
> @@ -2032,50 +2083,7 @@ retry:
>  			continue;
>  		}
>  
> -		wdata->sync_mode = wbc->sync_mode;
> -		wdata->nr_pages = nr_pages;
> -		wdata->offset = page_offset(wdata->pages[0]);
> -		wdata->pagesz = PAGE_CACHE_SIZE;
> -		wdata->tailsz =
> -			min(i_size_read(mapping->host) -
> -			    page_offset(wdata->pages[nr_pages - 1]),
> -			    (loff_t)PAGE_CACHE_SIZE);
> -		wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
> -					wdata->tailsz;
> -
> -		do {
> -			if (wdata->cfile != NULL)
> -				cifsFileInfo_put(wdata->cfile);
> -			wdata->cfile = find_writable_file(CIFS_I(mapping->host),
> -							  false);
> -			if (!wdata->cfile) {
> -				cifs_dbg(VFS, "No writable handles for inode\n");
> -				rc = -EBADF;
> -				break;
> -			}
> -			wdata->pid = wdata->cfile->pid;
> -			server = tlink_tcon(wdata->cfile->tlink)->ses->server;
> -			rc = server->ops->async_writev(wdata,
> -							cifs_writedata_release);
> -		} while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
> -
> -		for (i = 0; i < nr_pages; ++i)
> -			unlock_page(wdata->pages[i]);
> -
> -		/* send failure -- clean up the mess */
> -		if (rc != 0) {
> -			for (i = 0; i < nr_pages; ++i) {
> -				if (rc == -EAGAIN)
> -					redirty_page_for_writepage(wbc,
> -							   wdata->pages[i]);
> -				else
> -					SetPageError(wdata->pages[i]);
> -				end_page_writeback(wdata->pages[i]);
> -				page_cache_release(wdata->pages[i]);
> -			}
> -			if (rc != -EAGAIN)
> -				mapping_set_error(mapping, rc);
> -		}
> +		rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
>  		kref_put(&wdata->refcount, cifs_writedata_release);
>  
>  		wbc->nr_to_write -= nr_pages;

Reviewed-by: Jeff Layton <jlayton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>