diff options
| -rw-r--r-- | fs/mpage.c | 174 | ||||
| -rw-r--r-- | include/linux/mpage.h | 1 | ||||
| -rw-r--r-- | include/linux/writeback.h | 10 | ||||
| -rw-r--r-- | mm/page-writeback.c | 59 |
4 files changed, 93 insertions, 151 deletions
@@ -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); diff --git a/include/linux/mpage.h b/include/linux/mpage.h index cc5fb75..068a0c9 100644 --- a/include/linux/mpage.h +++ b/include/linux/mpage.h @@ -12,7 +12,6 @@ #ifdef CONFIG_BLOCK struct writeback_control; -typedef int (writepage_t)(struct page *page, struct writeback_control *wbc); int mpage_readpages(struct address_space *mapping, struct list_head *pages, unsigned nr_pages, get_block_t get_block); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index daa6c12..050915b 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -111,9 +111,15 @@ balance_dirty_pages_ratelimited(struct address_space *mapping) balance_dirty_pages_ratelimited_nr(mapping, 1); } +typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, + void *data); + int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0); -extern int generic_writepages(struct address_space *mapping, - struct writeback_control *wbc); +int generic_writepages(struct address_space *mapping, + struct writeback_control *wbc); +int write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc, writepage_t writepage, + void *data); int do_writepages(struct address_space *mapping, struct writeback_control *wbc); int sync_page_range(struct inode *inode, struct address_space *mapping, loff_t pos, loff_t count); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 63cd888..eec1481 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -588,31 +588,27 @@ void __init page_writeback_init(void) } /** - * generic_writepages - walk the list of dirty pages of the given address space and writepage() all of them. + * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write * @wbc: subtract the number of written pages from *@wbc->nr_to_write + * @writepage: function called for each page + * @data: data passed to writepage function * - * This is a library function, which implements the writepages() - * address_space_operation. - * - * If a page is already under I/O, generic_writepages() skips it, even + * If a page is already under I/O, write_cache_pages() skips it, even * if it's dirty. This is desirable behaviour for memory-cleaning writeback, * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() * and msync() need to guarantee that all the data which was dirty at the time * 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. - * - * Derived from mpage_writepages() - if you fix this you should check that - * also! */ -int generic_writepages(struct address_space *mapping, - struct writeback_control *wbc) +int write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc, writepage_t writepage, + void *data) { struct backing_dev_info *bdi = mapping->backing_dev_info; int ret = 0; int done = 0; - int (*writepage)(struct page *page, struct writeback_control *wbc); struct pagevec pvec; int nr_pages; pgoff_t index; @@ -625,12 +621,6 @@ int generic_writepages(struct address_space *mapping, return 0; } - writepage = mapping->a_ops->writepage; - - /* deal with chardevs and other special file */ - if (!writepage) - return 0; - pagevec_init(&pvec, 0); if (wbc->range_cyclic) { index = mapping->writeback_index; /* Start from prev offset */ @@ -682,8 +672,7 @@ retry: continue; } - ret = (*writepage)(page, wbc); - mapping_set_error(mapping, ret); + ret = (*writepage)(page, wbc, data); if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) unlock_page(page); @@ -710,6 +699,38 @@ retry: mapping->writeback_index = index; return ret; } +EXPORT_SYMBOL(write_cache_pages); + +/* + * Function used by generic_writepages to call the real writepage + * function and set the mapping flags on error + */ +static int __writepage(struct page *page, struct writeback_control *wbc, + void *data) +{ + struct address_space *mapping = data; + int ret = mapping->a_ops->writepage(page, wbc); + mapping_set_error(mapping, ret); + return ret; +} + +/** + * generic_writepages - walk the list of dirty pages of the given address space and writepage() all of them. + * @mapping: address space structure to write + * @wbc: subtract the number of written pages from *@wbc->nr_to_write + * + * This is a library function, which implements the writepages() + * address_space_operation. + */ +int generic_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + /* deal with chardevs and other special file */ + if (!mapping->a_ops->writepage) + return 0; + + return write_cache_pages(mapping, wbc, __writepage, mapping); +} EXPORT_SYMBOL(generic_writepages); |