From 7e48ff82026d99fe498a280faa55e5842288d72f Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Thu, 19 Jun 2014 15:01:03 +0400 Subject: [PATCH] CIFS: Separate page processing from writepages Signed-off-by: Pavel Shilovsky Reviewed-by: Jeff Layton Signed-off-by: Steve French --- 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 6b6df30cfd89..69d176396d04 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 @@ static int cifs_writepages(struct address_space *mapping, 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) { -- GitLab