diff options
Diffstat (limited to 'fs/mpage.c')
| -rw-r--r-- | fs/mpage.c | 132 |
1 files changed, 65 insertions, 67 deletions
diff --git a/fs/mpage.c b/fs/mpage.c index 42381bd6543..5f9ed622274 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -13,9 +13,10 @@ */ #include <linux/kernel.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/mm.h> #include <linux/kdev_t.h> +#include <linux/gfp.h> #include <linux/bio.h> #include <linux/fs.h> #include <linux/buffer_head.h> @@ -26,6 +27,7 @@ #include <linux/writeback.h> #include <linux/backing-dev.h> #include <linux/pagevec.h> +#include <linux/cleancache.h> /* * I/O completion handler for multipage BIOs. @@ -39,54 +41,22 @@ * status of that page is hard. See end_buffer_async_read() for the details. * There is no point in duplicating all that complexity. */ -static void mpage_end_io_read(struct bio *bio, int err) +static void mpage_end_io(struct bio *bio, int err) { - const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; + struct bio_vec *bv; + int i; - do { - struct page *page = bvec->bv_page; - - if (--bvec >= bio->bi_io_vec) - prefetchw(&bvec->bv_page->flags); - - if (uptodate) { - SetPageUptodate(page); - } else { - ClearPageUptodate(page); - SetPageError(page); - } - unlock_page(page); - } while (bvec >= bio->bi_io_vec); - bio_put(bio); -} - -static void mpage_end_io_write(struct bio *bio, int err) -{ - const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; - - do { - struct page *page = bvec->bv_page; - - if (--bvec >= bio->bi_io_vec) - prefetchw(&bvec->bv_page->flags); + bio_for_each_segment_all(bv, bio, i) { + struct page *page = bv->bv_page; + page_endio(page, bio_data_dir(bio), err); + } - if (!uptodate){ - SetPageError(page); - if (page->mapping) - set_bit(AS_EIO, &page->mapping->flags); - } - end_page_writeback(page); - } while (bvec >= bio->bi_io_vec); bio_put(bio); } static struct bio *mpage_bio_submit(int rw, struct bio *bio) { - bio->bi_end_io = mpage_end_io_read; - if (rw == WRITE) - bio->bi_end_io = mpage_end_io_write; + bio->bi_end_io = mpage_end_io; submit_bio(rw, bio); return NULL; } @@ -107,7 +77,7 @@ mpage_alloc(struct block_device *bdev, if (bio) { bio->bi_bdev = bdev; - bio->bi_sector = first_sector; + bio->bi_iter.bi_sector = first_sector; } return bio; } @@ -285,6 +255,12 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, SetPageMappedToDisk(page); } + if (fully_mapped && blocks_per_page == 1 && !PageUptodate(page) && + cleancache_get_page(page) == 0) { + SetPageUptodate(page); + goto confused; + } + /* * This page will go to BIO. Do we need to send this BIO off first? */ @@ -293,6 +269,11 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, alloc_new: if (bio == NULL) { + if (first_hole == blocks_per_page) { + if (!bdev_read_page(bdev, blocks[0] << (blkbits - 9), + page)) + goto out; + } bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), min_t(int, nr_pages, bio_get_nr_vecs(bdev)), GFP_KERNEL); @@ -447,6 +428,35 @@ struct mpage_data { unsigned use_writepage; }; +/* + * We have our BIO, so we can now mark the buffers clean. Make + * sure to only clean buffers which we know we'll be writing. + */ +static void clean_buffers(struct page *page, unsigned first_unmapped) +{ + unsigned buffer_counter = 0; + struct buffer_head *bh, *head; + if (!page_has_buffers(page)) + return; + head = page_buffers(page); + bh = head; + + do { + if (buffer_counter++ == first_unmapped) + break; + clear_buffer_dirty(bh); + bh = bh->b_this_page; + } while (bh != head); + + /* + * we cannot drop the bh if the page is not uptodate or a concurrent + * readpage would fail to serialize with the bh and it would read from + * disk before we reach the platter. + */ + if (buffer_heads_over_limit && PageUptodate(page)) + try_to_free_buffers(page); +} + static int __mpage_writepage(struct page *page, struct writeback_control *wbc, void *data) { @@ -561,7 +571,7 @@ page_is_mapped: if (page->index >= end_index) { /* * The page straddles i_size. It must be zeroed out on each - * and every writepage invokation because it may be mmapped. + * and every writepage invocation because it may be mmapped. * "A file is mapped in multiples of the page size. For a file * that is not a multiple of the page size, the remaining memory * is zeroed when mapped, and writes to that region are not @@ -582,6 +592,13 @@ page_is_mapped: alloc_new: if (bio == NULL) { + if (first_unmapped == blocks_per_page) { + if (!bdev_write_page(bdev, blocks[0] << (blkbits - 9), + page, wbc)) { + clean_buffers(page, first_unmapped); + goto out; + } + } bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), bio_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH); if (bio == NULL) @@ -599,30 +616,7 @@ alloc_new: goto alloc_new; } - /* - * OK, we have our BIO, so we can now mark the buffers clean. Make - * sure to only clean buffers which we know we'll be writing. - */ - if (page_has_buffers(page)) { - struct buffer_head *head = page_buffers(page); - struct buffer_head *bh = head; - unsigned buffer_counter = 0; - - do { - if (buffer_counter++ == first_unmapped) - break; - clear_buffer_dirty(bh); - bh = bh->b_this_page; - } while (bh != head); - - /* - * we cannot drop the bh if the page is not uptodate - * or a concurrent readpage would fail to serialize with the bh - * and it would read from disk before we reach the platter. - */ - if (buffer_heads_over_limit && PageUptodate(page)) - try_to_free_buffers(page); - } + clean_buffers(page, first_unmapped); BUG_ON(PageWriteback(page)); set_page_writeback(page); @@ -680,8 +674,11 @@ int mpage_writepages(struct address_space *mapping, struct writeback_control *wbc, get_block_t get_block) { + struct blk_plug plug; int ret; + blk_start_plug(&plug); + if (!get_block) ret = generic_writepages(mapping, wbc); else { @@ -696,6 +693,7 @@ mpage_writepages(struct address_space *mapping, if (mpd.bio) mpage_bio_submit(WRITE, mpd.bio); } + blk_finish_plug(&plug); return ret; } EXPORT_SYMBOL(mpage_writepages); |