From 0ea971801625184a91a6d80ea85e53875caa0bf5 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 10 May 2007 22:22:51 -0700 Subject: consolidate generic_writepages and mpage_writepages Clean up massive code duplication between mpage_writepages() and generic_writepages(). The new generic function, write_cache_pages() takes a function pointer argument, which will be called for each page to be written. Maybe cifs_writepages() too can use this infrastructure, but I'm not touching that with a ten-foot pole. The upcoming page writeback support in fuse will also want this. Signed-off-by: Miklos Szeredi Acked-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/mpage.c | 174 ++++++++++++++++--------------------------------------------- 1 file changed, 45 insertions(+), 129 deletions(-) (limited to 'fs') diff --git a/fs/mpage.c b/fs/mpage.c index 0fb914fc2ee0..c1698f2291aa 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -454,11 +454,18 @@ EXPORT_SYMBOL(mpage_readpage); * written, so it can intelligently allocate a suitably-sized BIO. For now, * just allocate full-size (16-page) BIOs. */ -static struct bio * -__mpage_writepage(struct bio *bio, struct page *page, get_block_t get_block, - sector_t *last_block_in_bio, int *ret, struct writeback_control *wbc, - writepage_t writepage_fn) +struct mpage_data { + struct bio *bio; + sector_t last_block_in_bio; + get_block_t *get_block; + unsigned use_writepage; +}; + +static int __mpage_writepage(struct page *page, struct writeback_control *wbc, + void *data) { + struct mpage_data *mpd = data; + struct bio *bio = mpd->bio; struct address_space *mapping = page->mapping; struct inode *inode = page->mapping->host; const unsigned blkbits = inode->i_blkbits; @@ -476,6 +483,7 @@ __mpage_writepage(struct bio *bio, struct page *page, get_block_t get_block, int length; struct buffer_head map_bh; loff_t i_size = i_size_read(inode); + int ret = 0; if (page_has_buffers(page)) { struct buffer_head *head = page_buffers(page); @@ -538,7 +546,7 @@ __mpage_writepage(struct bio *bio, struct page *page, get_block_t get_block, map_bh.b_state = 0; map_bh.b_size = 1 << blkbits; - if (get_block(inode, block_in_file, &map_bh, 1)) + if (mpd->get_block(inode, block_in_file, &map_bh, 1)) goto confused; if (buffer_new(&map_bh)) unmap_underlying_metadata(map_bh.b_bdev, @@ -584,7 +592,7 @@ page_is_mapped: /* * This page will go to BIO. Do we need to send this BIO off first? */ - if (bio && *last_block_in_bio != blocks[0] - 1) + if (bio && mpd->last_block_in_bio != blocks[0] - 1) bio = mpage_bio_submit(WRITE, bio); alloc_new: @@ -641,7 +649,7 @@ alloc_new: boundary_block, 1 << blkbits); } } else { - *last_block_in_bio = blocks[blocks_per_page - 1]; + mpd->last_block_in_bio = blocks[blocks_per_page - 1]; } goto out; @@ -649,18 +657,19 @@ confused: if (bio) bio = mpage_bio_submit(WRITE, bio); - if (writepage_fn) { - *ret = (*writepage_fn)(page, wbc); + if (mpd->use_writepage) { + ret = mapping->a_ops->writepage(page, wbc); } else { - *ret = -EAGAIN; + ret = -EAGAIN; goto out; } /* * The caller has a ref on the inode, so *mapping is stable */ - mapping_set_error(mapping, *ret); + mapping_set_error(mapping, ret); out: - return bio; + mpd->bio = bio; + return ret; } /** @@ -683,120 +692,27 @@ out: * the call was made get new I/O started against them. If wbc->sync_mode is * WB_SYNC_ALL then we were called for data integrity and we must wait for * existing IO to complete. - * - * If you fix this you should check generic_writepages() also! */ int mpage_writepages(struct address_space *mapping, struct writeback_control *wbc, get_block_t get_block) { - struct backing_dev_info *bdi = mapping->backing_dev_info; - struct bio *bio = NULL; - sector_t last_block_in_bio = 0; - int ret = 0; - int done = 0; - int (*writepage)(struct page *page, struct writeback_control *wbc); - struct pagevec pvec; - int nr_pages; - pgoff_t index; - pgoff_t end; /* Inclusive */ - int scanned = 0; - int range_whole = 0; - - if (wbc->nonblocking && bdi_write_congested(bdi)) { - wbc->encountered_congestion = 1; - return 0; - } - - writepage = NULL; - if (get_block == NULL) - writepage = mapping->a_ops->writepage; - - pagevec_init(&pvec, 0); - if (wbc->range_cyclic) { - index = mapping->writeback_index; /* Start from prev offset */ - end = -1; - } else { - index = wbc->range_start >> PAGE_CACHE_SHIFT; - end = wbc->range_end >> PAGE_CACHE_SHIFT; - if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) - range_whole = 1; - scanned = 1; + int ret; + + if (!get_block) + ret = generic_writepages(mapping, wbc); + else { + struct mpage_data mpd = { + .bio = NULL, + .last_block_in_bio = 0, + .get_block = get_block, + .use_writepage = 1, + }; + + ret = write_cache_pages(mapping, wbc, __mpage_writepage, &mpd); + if (mpd.bio) + mpage_bio_submit(WRITE, mpd.bio); } -retry: - while (!done && (index <= end) && - (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, - PAGECACHE_TAG_DIRTY, - min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { - unsigned i; - - scanned = 1; - for (i = 0; i < nr_pages; i++) { - struct page *page = pvec.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 - */ - - lock_page(page); - - if (unlikely(page->mapping != mapping)) { - unlock_page(page); - continue; - } - - if (!wbc->range_cyclic && page->index > end) { - done = 1; - unlock_page(page); - continue; - } - - if (wbc->sync_mode != WB_SYNC_NONE) - wait_on_page_writeback(page); - - if (PageWriteback(page) || - !clear_page_dirty_for_io(page)) { - unlock_page(page); - continue; - } - - if (writepage) { - ret = (*writepage)(page, wbc); - mapping_set_error(mapping, ret); - } else { - bio = __mpage_writepage(bio, page, get_block, - &last_block_in_bio, &ret, wbc, - page->mapping->a_ops->writepage); - } - if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) - unlock_page(page); - if (ret || (--(wbc->nr_to_write) <= 0)) - done = 1; - if (wbc->nonblocking && bdi_write_congested(bdi)) { - wbc->encountered_congestion = 1; - done = 1; - } - } - pagevec_release(&pvec); - cond_resched(); - } - if (!scanned && !done) { - /* - * We hit the last page and there is more work to be done: wrap - * back to the start of the file - */ - scanned = 1; - index = 0; - goto retry; - } - if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) - mapping->writeback_index = index; - if (bio) - mpage_bio_submit(WRITE, bio); return ret; } EXPORT_SYMBOL(mpage_writepages); @@ -804,15 +720,15 @@ EXPORT_SYMBOL(mpage_writepages); int mpage_writepage(struct page *page, get_block_t get_block, struct writeback_control *wbc) { - int ret = 0; - struct bio *bio; - sector_t last_block_in_bio = 0; - - bio = __mpage_writepage(NULL, page, get_block, - &last_block_in_bio, &ret, wbc, NULL); - if (bio) - mpage_bio_submit(WRITE, bio); - + struct mpage_data mpd = { + .bio = NULL, + .last_block_in_bio = 0, + .get_block = get_block, + .use_writepage = 0, + }; + int ret = __mpage_writepage(page, wbc, &mpd); + if (mpd.bio) + mpage_bio_submit(WRITE, mpd.bio); return ret; } EXPORT_SYMBOL(mpage_writepage); -- cgit v1.2.3