From cb20d5188366f04d96d2e07b1240cc92170ade40 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 27 Oct 2010 21:30:09 -0400 Subject: ext4: inline ext4_writepage() into mpage_da_submit_io() As a prepratory step to switching to bio_submit, inline ext4_writepage() into mpage_da_submit() and then simplify things a bit. This makes it clearer what mpage_da_submit needs to do. Also, move the ClearPageChecked(page) call into __ext4_journalled_writepage(), as a minor bit of cleanup refactoring. This also allows us to pull i_size_read() and ext4_should_journal_data() out of the loop, which should be a very minor CPU savings. Signed-off-by: "Theodore Ts'o" --- fs/ext4/inode.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 59 insertions(+), 11 deletions(-) (limited to 'fs/ext4/inode.c') diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index a08ec795995..97a0c35219a 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -60,7 +60,12 @@ static inline int ext4_begin_ordered_truncate(struct inode *inode, } static void ext4_invalidatepage(struct page *page, unsigned long offset); -static int ext4_writepage(struct page *page, struct writeback_control *wbc); +static int noalloc_get_block_write(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create); +static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode); +static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate); +static int __ext4_journalled_writepage(struct page *page, unsigned int len); +static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh); /* * Test whether an inode is a fast symlink. @@ -2000,12 +2005,15 @@ static void ext4_da_page_release_reservation(struct page *page, */ static int mpage_da_submit_io(struct mpage_da_data *mpd) { - long pages_skipped; struct pagevec pvec; unsigned long index, end; int ret = 0, err, nr_pages, i; struct inode *inode = mpd->inode; struct address_space *mapping = inode->i_mapping; + loff_t size = i_size_read(inode); + unsigned int len; + struct buffer_head *page_bufs = NULL; + int journal_data = ext4_should_journal_data(inode); BUG_ON(mpd->next_page <= mpd->first_page); /* @@ -2023,28 +2031,69 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd) if (nr_pages == 0) break; for (i = 0; i < nr_pages; i++) { + int commit_write = 0; struct page *page = pvec.pages[i]; index = page->index; if (index > end) break; + + if (index == size >> PAGE_CACHE_SHIFT) + len = size & ~PAGE_CACHE_MASK; + else + len = PAGE_CACHE_SIZE; index++; BUG_ON(!PageLocked(page)); BUG_ON(PageWriteback(page)); - pages_skipped = mpd->wbc->pages_skipped; - err = ext4_writepage(page, mpd->wbc); - if (!err && (pages_skipped == mpd->wbc->pages_skipped)) + /* + * If the page does not have buffers (for + * whatever reason), try to create them using + * block_prepare_write. If this fails, + * redirty the page and move on. + */ + if (!page_has_buffers(page)) { + if (block_prepare_write(page, 0, len, + noalloc_get_block_write)) { + redirty_page: + redirty_page_for_writepage(mpd->wbc, + page); + unlock_page(page); + continue; + } + commit_write = 1; + } + page_bufs = page_buffers(page); + if (walk_page_buffers(NULL, page_bufs, 0, len, NULL, + ext4_bh_delay_or_unwritten)) { /* - * have successfully written the page - * without skipping the same + * We couldn't do block allocation for + * some reason. */ + goto redirty_page; + } + + if (commit_write) + /* mark the buffer_heads as dirty & uptodate */ + block_commit_write(page, 0, len); + + if (journal_data && PageChecked(page)) + err = __ext4_journalled_writepage(page, len); + else if (buffer_uninit(page_bufs)) { + ext4_set_bh_endio(page_bufs, inode); + err = block_write_full_page_endio(page, + noalloc_get_block_write, + mpd->wbc, ext4_end_io_buffer_write); + } else + err = block_write_full_page(page, + noalloc_get_block_write, mpd->wbc); + + if (!err) mpd->pages_written++; /* * In error case, we have to continue because * remaining pages are still locked - * XXX: unlock and re-dirty them? */ if (ret == 0) ret = err; @@ -2627,6 +2676,7 @@ static int __ext4_journalled_writepage(struct page *page, int ret = 0; int err; + ClearPageChecked(page); page_bufs = page_buffers(page); BUG_ON(!page_bufs); walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one); @@ -2749,14 +2799,12 @@ static int ext4_writepage(struct page *page, /* now mark the buffer_heads as dirty and uptodate */ block_commit_write(page, 0, len); - if (PageChecked(page) && ext4_should_journal_data(inode)) { + if (PageChecked(page) && ext4_should_journal_data(inode)) /* * It's mmapped pagecache. Add buffers and journal it. There * doesn't seem much point in redirtying the page here. */ - ClearPageChecked(page); return __ext4_journalled_writepage(page, len); - } if (buffer_uninit(page_bufs)) { ext4_set_bh_endio(page_bufs, inode); -- cgit v1.2.3