consolidate generic_writepages and mpage_writepages (0ea97180) · Commits · e / devices / android_kernel_teracube_emerald

fs/mpage.c

+45 −129

Original line number	Original line	Diff line number	Diff line
	@@ -454,11 +454,18 @@ EXPORT_SYMBOL(mpage_readpage);
	* written, so it can intelligently allocate a suitably-sized BIO. For now,		* written, so it can intelligently allocate a suitably-sized BIO. For now,
	* just allocate full-size (16-page) BIOs.		* just allocate full-size (16-page) BIOs.
	*/		*/
	static struct bio *		struct mpage_data {
	__mpage_writepage(struct bio bio, struct page page, get_block_t get_block,		struct bio *bio;
	sector_t last_block_in_bio, int ret, struct writeback_control *wbc,		sector_t last_block_in_bio;
	writepage_t writepage_fn)		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 address_space *mapping = page->mapping;
	struct inode *inode = page->mapping->host;		struct inode *inode = page->mapping->host;
	const unsigned blkbits = inode->i_blkbits;		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;		int length;
	struct buffer_head map_bh;		struct buffer_head map_bh;
	loff_t i_size = i_size_read(inode);		loff_t i_size = i_size_read(inode);
			int ret = 0;

	if (page_has_buffers(page)) {		if (page_has_buffers(page)) {
	struct buffer_head *head = page_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_state = 0;
	map_bh.b_size = 1 << blkbits;		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;		goto confused;
	if (buffer_new(&map_bh))		if (buffer_new(&map_bh))
	unmap_underlying_metadata(map_bh.b_bdev,		unmap_underlying_metadata(map_bh.b_bdev,
	@@ -584,7 +592,7 @@ __mpage_writepage(struct bio bio, struct page page, get_block_t get_block,
	/*		/*
	* This page will go to BIO. Do we need to send this BIO off first?		* 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);		bio = mpage_bio_submit(WRITE, bio);

	alloc_new:		alloc_new:
	@@ -641,7 +649,7 @@ __mpage_writepage(struct bio bio, struct page page, get_block_t get_block,
	boundary_block, 1 << blkbits);		boundary_block, 1 << blkbits);
	}		}
	} else {		} else {
	*last_block_in_bio = blocks[blocks_per_page - 1];		mpd->last_block_in_bio = blocks[blocks_per_page - 1];
	}		}
	goto out;		goto out;

	@@ -649,18 +657,19 @@ __mpage_writepage(struct bio bio, struct page page, get_block_t get_block,
	if (bio)		if (bio)
	bio = mpage_bio_submit(WRITE, bio);		bio = mpage_bio_submit(WRITE, bio);

	if (writepage_fn) {		if (mpd->use_writepage) {
	ret = (writepage_fn)(page, wbc);		ret = mapping->a_ops->writepage(page, wbc);
	} else {		} else {
	*ret = -EAGAIN;		ret = -EAGAIN;
	goto out;		goto out;
	}		}
	/*		/*
	* The caller has a ref on the inode, so *mapping is stable		* The caller has a ref on the inode, so *mapping is stable
	*/		*/
	mapping_set_error(mapping, *ret);		mapping_set_error(mapping, ret);
	out:		out:
	return bio;		mpd->bio = bio;
			return ret;
	}		}

	/**		/**
	@@ -683,120 +692,27 @@ __mpage_writepage(struct bio bio, struct page page, get_block_t get_block,
	* the call was made get new I/O started against them. If wbc->sync_mode is		* 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		* WB_SYNC_ALL then we were called for data integrity and we must wait for
	* existing IO to complete.		* existing IO to complete.
	*
	* If you fix this you should check generic_writepages() also!
	*/		*/
	int		int
	mpage_writepages(struct address_space *mapping,		mpage_writepages(struct address_space *mapping,
	struct writeback_control *wbc, get_block_t get_block)		struct writeback_control *wbc, get_block_t get_block)
	{		{
	struct backing_dev_info *bdi = mapping->backing_dev_info;		int ret;
	struct bio *bio = NULL;
	sector_t last_block_in_bio = 0;		if (!get_block)
	int ret = 0;		ret = generic_writepages(mapping, wbc);
	int done = 0;		else {
	int (writepage)(struct page page, struct writeback_control *wbc);		struct mpage_data mpd = {
	struct pagevec pvec;		.bio = NULL,
	int nr_pages;		.last_block_in_bio = 0,
	pgoff_t index;		.get_block = get_block,
	pgoff_t end; /* Inclusive */		.use_writepage = 1,
	int scanned = 0;		};
	int range_whole = 0;
			ret = write_cache_pages(mapping, wbc, __mpage_writepage, &mpd);
	if (wbc->nonblocking && bdi_write_congested(bdi)) {		if (mpd.bio)
	wbc->encountered_congestion = 1;		mpage_bio_submit(WRITE, mpd.bio);
	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;
	}
	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;		return ret;
	}		}
	EXPORT_SYMBOL(mpage_writepages);		EXPORT_SYMBOL(mpage_writepages);
	@@ -804,15 +720,15 @@ EXPORT_SYMBOL(mpage_writepages);
	int mpage_writepage(struct page *page, get_block_t get_block,		int mpage_writepage(struct page *page, get_block_t get_block,
	struct writeback_control *wbc)		struct writeback_control *wbc)
	{		{
	int ret = 0;		struct mpage_data mpd = {
	struct bio *bio;		.bio = NULL,
	sector_t last_block_in_bio = 0;		.last_block_in_bio = 0,
			.get_block = get_block,
	bio = __mpage_writepage(NULL, page, get_block,		.use_writepage = 0,
	&last_block_in_bio, &ret, wbc, NULL);		};
	if (bio)		int ret = __mpage_writepage(page, wbc, &mpd);
	mpage_bio_submit(WRITE, bio);		if (mpd.bio)
			mpage_bio_submit(WRITE, mpd.bio);
	return ret;		return ret;
	}		}
	EXPORT_SYMBOL(mpage_writepage);		EXPORT_SYMBOL(mpage_writepage);

include/linux/mpage.h

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -12,7 +12,6 @@
	#ifdef CONFIG_BLOCK		#ifdef CONFIG_BLOCK

	struct writeback_control;		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,		int mpage_readpages(struct address_space mapping, struct list_head pages,
	unsigned nr_pages, get_block_t get_block);		unsigned nr_pages, get_block_t get_block);

include/linux/writeback.h

+8 −2

Original line number	Original line	Diff line number	Diff line
	@@ -111,9 +111,15 @@ balance_dirty_pages_ratelimited(struct address_space *mapping)
	balance_dirty_pages_ratelimited_nr(mapping, 1);		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);		int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0);
	extern int generic_writepages(struct address_space *mapping,		int generic_writepages(struct address_space *mapping,
	struct writeback_control *wbc);		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 do_writepages(struct address_space mapping, struct writeback_control wbc);
	int sync_page_range(struct inode inode, struct address_space mapping,		int sync_page_range(struct inode inode, struct address_space mapping,
	loff_t pos, loff_t count);		loff_t pos, loff_t count);

mm/page-writeback.c

+40 −19

Original line number	Original line	Diff line number	Diff line
	@@ -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		* @mapping: address space structure to write
	* @wbc: subtract the number of written pages from *@wbc->nr_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()		* If a page is already under I/O, write_cache_pages() skips it, even
	* address_space_operation.
	*
	* If a page is already under I/O, generic_writepages() skips it, even
	* if it's dirty. This is desirable behaviour for memory-cleaning writeback,		* 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()		* 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		* 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		* 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		* WB_SYNC_ALL then we were called for data integrity and we must wait for
	* existing IO to complete.		* existing IO to complete.
	*
	* Derived from mpage_writepages() - if you fix this you should check that
	* also!
	*/		*/
	int generic_writepages(struct address_space *mapping,		int write_cache_pages(struct address_space *mapping,
	struct writeback_control *wbc)		struct writeback_control *wbc, writepage_t writepage,
			void *data)
	{		{
	struct backing_dev_info *bdi = mapping->backing_dev_info;		struct backing_dev_info *bdi = mapping->backing_dev_info;
	int ret = 0;		int ret = 0;
	int done = 0;		int done = 0;
	int (writepage)(struct page page, struct writeback_control *wbc);
	struct pagevec pvec;		struct pagevec pvec;
	int nr_pages;		int nr_pages;
	pgoff_t index;		pgoff_t index;
	@@ -625,12 +621,6 @@ int generic_writepages(struct address_space *mapping,
	return 0;		return 0;
	}		}

	writepage = mapping->a_ops->writepage;

	/* deal with chardevs and other special file */
	if (!writepage)
	return 0;

	pagevec_init(&pvec, 0);		pagevec_init(&pvec, 0);
	if (wbc->range_cyclic) {		if (wbc->range_cyclic) {
	index = mapping->writeback_index; /* Start from prev offset */		index = mapping->writeback_index; /* Start from prev offset */
	@@ -682,8 +672,7 @@ int generic_writepages(struct address_space *mapping,
	continue;		continue;
	}		}

	ret = (*writepage)(page, wbc);		ret = (*writepage)(page, wbc, data);
	mapping_set_error(mapping, ret);

	if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE))		if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE))
	unlock_page(page);		unlock_page(page);
	@@ -710,6 +699,38 @@ int generic_writepages(struct address_space *mapping,
	mapping->writeback_index = index;		mapping->writeback_index = index;
	return ret;		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);		EXPORT_SYMBOL(generic_writepages);