On Fri, 27 Jun 2014 13:57:39 +0400
Pavel Shilovsky <pshilovsky@xxxxxxxxx> wrote:
> Signed-off-by: Pavel Shilovsky <pshilovsky@xxxxxxxxx>
> ---
> fs/cifs/file.c | 152 +++++++++++++++++++++++++++++++--------------------------
> 1 file changed, 82 insertions(+), 70 deletions(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 6b6df30..69d1763 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -1878,6 +1878,86 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
> return rc;
> }
>
> +static unsigned int
> +wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
> + struct address_space *mapping,
> + struct writeback_control *wbc,
> + pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
> +{
> + unsigned int nr_pages = 0, i;
> + struct page *page;
> +
> + for (i = 0; i < found_pages; i++) {
> + page = wdata->pages[i];
> + /*
> + * At this point we hold neither mapping->tree_lock nor
> + * lock on the page itself: the page may be truncated or
> + * invalidated (changing page->mapping to NULL), or even
> + * swizzled back from swapper_space to tmpfs file
> + * mapping
> + */
> +
> + if (nr_pages == 0)
> + lock_page(page);
> + else if (!trylock_page(page))
> + break;
> +
> + if (unlikely(page->mapping != mapping)) {
> + unlock_page(page);
> + break;
> + }
> +
> + if (!wbc->range_cyclic && page->index > end) {
> + *done = true;
> + unlock_page(page);
> + break;
> + }
> +
> + if (*next && (page->index != *next)) {
> + /* Not next consecutive page */
> + unlock_page(page);
> + break;
> + }
> +
> + if (wbc->sync_mode != WB_SYNC_NONE)
> + wait_on_page_writeback(page);
> +
> + if (PageWriteback(page) ||
> + !clear_page_dirty_for_io(page)) {
> + unlock_page(page);
> + break;
> + }
> +
> + /*
> + * This actually clears the dirty bit in the radix tree.
> + * See cifs_writepage() for more commentary.
> + */
> + set_page_writeback(page);
> + if (page_offset(page) >= i_size_read(mapping->host)) {
> + *done = true;
> + unlock_page(page);
> + end_page_writeback(page);
> + break;
> + }
> +
> + wdata->pages[i] = page;
> + *next = page->index + 1;
> + ++nr_pages;
> + }
> +
> + /* reset index to refind any pages skipped */
> + if (nr_pages == 0)
> + *index = wdata->pages[0]->index + 1;
> +
> + /* put any pages we aren't going to use */
> + for (i = nr_pages; i < found_pages; i++) {
> + page_cache_release(wdata->pages[i]);
> + wdata->pages[i] = NULL;
> + }
> +
> + return nr_pages;
> +}
> +
> static int cifs_writepages(struct address_space *mapping,
> struct writeback_control *wbc)
> {
> @@ -1886,7 +1966,6 @@ static int cifs_writepages(struct address_space *mapping,
> pgoff_t end, index;
> struct cifs_writedata *wdata;
> struct TCP_Server_Info *server;
> - struct page *page;
> int rc = 0;
>
> /*
> @@ -1944,75 +2023,8 @@ retry:
> break;
> }
>
> - nr_pages = 0;
> - for (i = 0; i < found_pages; i++) {
> - page = wdata->pages[i];
> - /*
> - * At this point we hold neither mapping->tree_lock nor
> - * lock on the page itself: the page may be truncated or
> - * invalidated (changing page->mapping to NULL), or even
> - * swizzled back from swapper_space to tmpfs file
> - * mapping
> - */
> -
> - if (nr_pages == 0)
> - lock_page(page);
> - else if (!trylock_page(page))
> - break;
> -
> - if (unlikely(page->mapping != mapping)) {
> - unlock_page(page);
> - break;
> - }
> -
> - if (!wbc->range_cyclic && page->index > end) {
> - done = true;
> - unlock_page(page);
> - break;
> - }
> -
> - if (next && (page->index != next)) {
> - /* Not next consecutive page */
> - unlock_page(page);
> - break;
> - }
> -
> - if (wbc->sync_mode != WB_SYNC_NONE)
> - wait_on_page_writeback(page);
> -
> - if (PageWriteback(page) ||
> - !clear_page_dirty_for_io(page)) {
> - unlock_page(page);
> - break;
> - }
> -
> - /*
> - * This actually clears the dirty bit in the radix tree.
> - * See cifs_writepage() for more commentary.
> - */
> - set_page_writeback(page);
> -
> - if (page_offset(page) >= i_size_read(mapping->host)) {
> - done = true;
> - unlock_page(page);
> - end_page_writeback(page);
> - break;
> - }
> -
> - wdata->pages[i] = page;
> - next = page->index + 1;
> - ++nr_pages;
> - }
> -
> - /* reset index to refind any pages skipped */
> - if (nr_pages == 0)
> - index = wdata->pages[0]->index + 1;
> -
> - /* put any pages we aren't going to use */
> - for (i = nr_pages; i < found_pages; i++) {
> - page_cache_release(wdata->pages[i]);
> - wdata->pages[i] = NULL;
> - }
> + nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
> + end, &index, &next, &done);
>
> /* nothing to write? */
> if (nr_pages == 0) {
Reviewed-by:
--
Jeff Layton <jlayton@xxxxxxxxx>
--
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