[GitHub/mt8127/android_kernel_alcatel_ttab.git] / mm / page_io.c

/*
 *  linux/mm/page_io.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Swap reorganised 29.12.95, 
 *  Asynchronous swapping added 30.12.95. Stephen Tweedie
 *  Removed race in async swapping. 14.4.1996. Bruno Haible
 *  Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie
 *  Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman
 */

#include <linux/mm.h>
#include <linux/kernel_stat.h>
#include <linux/gfp.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/bio.h>
#include <linux/swapops.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/frontswap.h>
#include <linux/aio.h>
#include <linux/blkdev.h>
#include <asm/pgtable.h>

static struct bio *get_swap_bio(gfp_t gfp_flags,
				struct page *page, bio_end_io_t end_io)
{
	struct bio *bio;

	bio = bio_alloc(gfp_flags, 1);
	if (bio) {
		bio->bi_sector = map_swap_page(page, &bio->bi_bdev);
		bio->bi_sector <<= PAGE_SHIFT - 9;
		bio->bi_io_vec[0].bv_page = page;
		bio->bi_io_vec[0].bv_len = PAGE_SIZE;
		bio->bi_io_vec[0].bv_offset = 0;
		bio->bi_vcnt = 1;
		bio->bi_size = PAGE_SIZE;
		bio->bi_end_io = end_io;
	}
	return bio;
}

void end_swap_bio_write(struct bio *bio, int err)
{
	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
	struct page *page = bio->bi_io_vec[0].bv_page;

	if (!uptodate) {
		if (!task_in_mtkpasr(current)) {
			SetPageError(page);
		}
		/*
		 * We failed to write the page out to swap-space.
		 * Re-dirty the page in order to avoid it being reclaimed.
		 * Also print a dire warning that things will go BAD (tm)
		 * very quickly.
		 *
		 * Also clear PG_reclaim to avoid rotate_reclaimable_page()
		 */
		set_page_dirty(page);
		if (!task_in_mtkpasr(current)) {
			printk(KERN_ALERT "Write-error on swap-device (%u:%u:%Lu)\n",
					imajor(bio->bi_bdev->bd_inode),
					iminor(bio->bi_bdev->bd_inode),
					(unsigned long long)bio->bi_sector);
		}
		ClearPageReclaim(page);
	}
	end_page_writeback(page);
	bio_put(bio);
}

void end_swap_bio_read(struct bio *bio, int err)
{
	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
	struct page *page = bio->bi_io_vec[0].bv_page;

	if (!uptodate) {
		SetPageError(page);
		ClearPageUptodate(page);
		printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
				imajor(bio->bi_bdev->bd_inode),
				iminor(bio->bi_bdev->bd_inode),
				(unsigned long long)bio->bi_sector);
		goto out;
	}

	SetPageUptodate(page);

	/*
	 * There is no guarantee that the page is in swap cache - the software
	 * suspend code (at least) uses end_swap_bio_read() against a non-
	 * swapcache page.  So we must check PG_swapcache before proceeding with
	 * this optimization.
	 */
	if (likely(PageSwapCache(page))) {
		struct swap_info_struct *sis;

		sis = page_swap_info(page);
		if (sis->flags & SWP_BLKDEV) {
			/*
			 * The swap subsystem performs lazy swap slot freeing,
			 * expecting that the page will be swapped out again.
			 * So we can avoid an unnecessary write if the page
			 * isn't redirtied.
			 * This is good for real swap storage because we can
			 * reduce unnecessary I/O and enhance wear-leveling
			 * if an SSD is used as the as swap device.
			 * But if in-memory swap device (eg zram) is used,
			 * this causes a duplicated copy between uncompressed
			 * data in VM-owned memory and compressed data in
			 * zram-owned memory.  So let's free zram-owned memory
			 * and make the VM-owned decompressed page *dirty*,
			 * so the page should be swapped out somewhere again if
			 * we again wish to reclaim it.
			 */
			struct gendisk *disk = sis->bdev->bd_disk;
			if (disk->fops->swap_slot_free_notify) {
				swp_entry_t entry;
				unsigned long offset;

				entry.val = page_private(page);
				offset = swp_offset(entry);

				SetPageDirty(page);
				disk->fops->swap_slot_free_notify(sis->bdev,
						offset);
			}
		}
	}

out:
	unlock_page(page);
	bio_put(bio);
}

int generic_swapfile_activate(struct swap_info_struct *sis,
				struct file *swap_file,
				sector_t *span)
{
	struct address_space *mapping = swap_file->f_mapping;
	struct inode *inode = mapping->host;
	unsigned blocks_per_page;
	unsigned long page_no;
	unsigned blkbits;
	sector_t probe_block;
	sector_t last_block;
	sector_t lowest_block = -1;
	sector_t highest_block = 0;
	int nr_extents = 0;
	int ret;

	blkbits = inode->i_blkbits;
	blocks_per_page = PAGE_SIZE >> blkbits;

	/*
	 * Map all the blocks into the extent list.  This code doesn't try
	 * to be very smart.
	 */
	probe_block = 0;
	page_no = 0;
	last_block = i_size_read(inode) >> blkbits;
	while ((probe_block + blocks_per_page) <= last_block &&
			page_no < sis->max) {
		unsigned block_in_page;
		sector_t first_block;

		first_block = bmap(inode, probe_block);
		if (first_block == 0)
			goto bad_bmap;

		/*
		 * It must be PAGE_SIZE aligned on-disk
		 */
		if (first_block & (blocks_per_page - 1)) {
			probe_block++;
			goto reprobe;
		}

		for (block_in_page = 1; block_in_page < blocks_per_page;
					block_in_page++) {
			sector_t block;

			block = bmap(inode, probe_block + block_in_page);
			if (block == 0)
				goto bad_bmap;
			if (block != first_block + block_in_page) {
				/* Discontiguity */
				probe_block++;
				goto reprobe;
			}
		}

		first_block >>= (PAGE_SHIFT - blkbits);
		if (page_no) {	/* exclude the header page */
			if (first_block < lowest_block)
				lowest_block = first_block;
			if (first_block > highest_block)
				highest_block = first_block;
		}

		/*
		 * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
		 */
		ret = add_swap_extent(sis, page_no, 1, first_block);
		if (ret < 0)
			goto out;
		nr_extents += ret;
		page_no++;
		probe_block += blocks_per_page;
reprobe:
		continue;
	}
	ret = nr_extents;
	*span = 1 + highest_block - lowest_block;
	if (page_no == 0)
		page_no = 1;	/* force Empty message */
	sis->max = page_no;
	sis->pages = page_no - 1;
	sis->highest_bit = page_no - 1;
out:
	return ret;
bad_bmap:
	printk(KERN_ERR "swapon: swapfile has holes\n");
	ret = -EINVAL;
	goto out;
}

/*
 * We may have stale swap cache pages in memory: notice
 * them here and get rid of the unnecessary final write.
 */
int swap_writepage(struct page *page, struct writeback_control *wbc)
{
	int ret = 0;

	if (try_to_free_swap(page)) {
		unlock_page(page);
		goto out;
	}
	if (frontswap_store(page) == 0) {
		set_page_writeback(page);
		unlock_page(page);
		end_page_writeback(page);
		goto out;
	}
	ret = __swap_writepage(page, wbc, end_swap_bio_write);
out:
	return ret;
}

int __swap_writepage(struct page *page, struct writeback_control *wbc,
	void (*end_write_func)(struct bio *, int))
{
	struct bio *bio;
	int ret = 0, rw = WRITE;
	struct swap_info_struct *sis = page_swap_info(page);

	if (sis->flags & SWP_FILE) {
		struct kiocb kiocb;
		struct file *swap_file = sis->swap_file;
		struct address_space *mapping = swap_file->f_mapping;
		struct iovec iov = {
			.iov_base = kmap(page),
			.iov_len  = PAGE_SIZE,
		};

		init_sync_kiocb(&kiocb, swap_file);
		kiocb.ki_pos = page_file_offset(page);
		kiocb.ki_left = PAGE_SIZE;
		kiocb.ki_nbytes = PAGE_SIZE;

		set_page_writeback(page);
		unlock_page(page);
		ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
						&kiocb, &iov,
						kiocb.ki_pos, 1);
		kunmap(page);
		if (ret == PAGE_SIZE) {
			count_vm_event(PSWPOUT);
			ret = 0;
		} else {
			/*
			 * In the case of swap-over-nfs, this can be a
			 * temporary failure if the system has limited
			 * memory for allocating transmit buffers.
			 * Mark the page dirty and avoid
			 * rotate_reclaimable_page but rate-limit the
			 * messages but do not flag PageError like
			 * the normal direct-to-bio case as it could
			 * be temporary.
			 */
			set_page_dirty(page);
			ClearPageReclaim(page);
			pr_err_ratelimited("Write error on dio swapfile (%Lu)\n",
				page_file_offset(page));
		}
		end_page_writeback(page);
		return ret;
	}

	bio = get_swap_bio(GFP_NOIO, page, end_write_func);
	if (bio == NULL) {
		set_page_dirty(page);
		unlock_page(page);
		ret = -ENOMEM;
		goto out;
	}
	if (wbc->sync_mode == WB_SYNC_ALL)
		rw |= REQ_SYNC;

#ifdef CONFIG_ZRAM
    current->swap_out++;
#endif
	count_vm_event(PSWPOUT);
	set_page_writeback(page);
	unlock_page(page);
	submit_bio(rw, bio);
out:
	return ret;
}

int swap_readpage(struct page *page)
{
	struct bio *bio;
	int ret = 0;
	struct swap_info_struct *sis = page_swap_info(page);

	VM_BUG_ON(!PageLocked(page));
	VM_BUG_ON(PageUptodate(page));
	if (frontswap_load(page) == 0) {
		SetPageUptodate(page);
		unlock_page(page);
		goto out;
	}

	if (sis->flags & SWP_FILE) {
		struct file *swap_file = sis->swap_file;
		struct address_space *mapping = swap_file->f_mapping;

		ret = mapping->a_ops->readpage(swap_file, page);
		if (!ret) {
#ifdef CONFIG_ZRAM
			current->swap_in++;
#endif
			count_vm_event(PSWPIN);
		}
		return ret;
	}

	bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
	if (bio == NULL) {
		unlock_page(page);
		ret = -ENOMEM;
		goto out;
	}

#ifdef CONFIG_ZRAM
	current->swap_in++;
#endif
	count_vm_event(PSWPIN);
	submit_bio(READ, bio);
out:
	return ret;
}

int swap_set_page_dirty(struct page *page)
{
	struct swap_info_struct *sis = page_swap_info(page);

	if (sis->flags & SWP_FILE) {
		struct address_space *mapping = sis->swap_file->f_mapping;
		return mapping->a_ops->set_page_dirty(page);
	} else {
		return __set_page_dirty_no_writeback(page);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/mm/page_io.c
	3	*
	4	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
	5	*
	6	* Swap reorganised 29.12.95,
	7	* Asynchronous swapping added 30.12.95. Stephen Tweedie
	8	* Removed race in async swapping. 14.4.1996. Bruno Haible
	9	* Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie
	10	* Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman
	11	*/
	12
	13	#include <linux/mm.h>
	14	#include <linux/kernel_stat.h>
5a0e3ad6	15	#include <linux/gfp.h>
1da177e4 LT	16	#include <linux/pagemap.h>
	17	#include <linux/swap.h>
	18	#include <linux/bio.h>
	19	#include <linux/swapops.h>
62c230bc	20	#include <linux/buffer_head.h>
1da177e4	21	#include <linux/writeback.h>
38b5faf4	22	#include <linux/frontswap.h>
a27bb332	23	#include <linux/aio.h>
6fa3eb70	24	#include <linux/blkdev.h>
1da177e4 LT	25	#include <asm/pgtable.h>
1da177e4 LT	26
f29ad6a9	27	static struct bio *get_swap_bio(gfp_t gfp_flags,
1da177e4 LT	28	struct page *page, bio_end_io_t end_io)
	29	{
	30	struct bio *bio;
	31
	32	bio = bio_alloc(gfp_flags, 1);
	33	if (bio) {
d4906e1a	34	bio->bi_sector = map_swap_page(page, &bio->bi_bdev);
f29ad6a9	35	bio->bi_sector <<= PAGE_SHIFT - 9;
1da177e4 LT	36	bio->bi_io_vec[0].bv_page = page;
	37	bio->bi_io_vec[0].bv_len = PAGE_SIZE;
	38	bio->bi_io_vec[0].bv_offset = 0;
	39	bio->bi_vcnt = 1;
1da177e4 LT	40	bio->bi_size = PAGE_SIZE;
	41	bio->bi_end_io = end_io;
	42	}
	43	return bio;
	44	}
	45
1eec6702	46	void end_swap_bio_write(struct bio *bio, int err)
1da177e4 LT	47	{
	48	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
	49	struct page *page = bio->bi_io_vec[0].bv_page;
	50
6ddab3b9	51	if (!uptodate) {
6fa3eb70 S	52	if (!task_in_mtkpasr(current)) {
	53	SetPageError(page);
	54	}
6ddab3b9 PZ	55	/*
	56	* We failed to write the page out to swap-space.
	57	* Re-dirty the page in order to avoid it being reclaimed.
	58	* Also print a dire warning that things will go BAD (tm)
	59	* very quickly.
	60	*
	61	* Also clear PG_reclaim to avoid rotate_reclaimable_page()
	62	*/
	63	set_page_dirty(page);
6fa3eb70 S	64	if (!task_in_mtkpasr(current)) {
	65	printk(KERN_ALERT "Write-error on swap-device (%u:%u:%Lu)\n",
	66	imajor(bio->bi_bdev->bd_inode),
	67	iminor(bio->bi_bdev->bd_inode),
	68	(unsigned long long)bio->bi_sector);
	69	}
6ddab3b9 PZ	70	ClearPageReclaim(page);
6ddab3b9 PZ	71	}
1da177e4 LT	72	end_page_writeback(page);
1da177e4 LT	73	bio_put(bio);
1da177e4 LT	74	}
1da177e4 LT	75
6712ecf8	76	void end_swap_bio_read(struct bio *bio, int err)
1da177e4 LT	77	{
	78	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
	79	struct page *page = bio->bi_io_vec[0].bv_page;
	80
1da177e4 LT	81	if (!uptodate) {
	82	SetPageError(page);
	83	ClearPageUptodate(page);
6ddab3b9 PZ	84	printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
	85	imajor(bio->bi_bdev->bd_inode),
	86	iminor(bio->bi_bdev->bd_inode),
	87	(unsigned long long)bio->bi_sector);
6fa3eb70 S	88	goto out;
	89	}
	90
	91	SetPageUptodate(page);
	92
	93	/*
	94	* There is no guarantee that the page is in swap cache - the software
	95	* suspend code (at least) uses end_swap_bio_read() against a non-
	96	* swapcache page. So we must check PG_swapcache before proceeding with
	97	* this optimization.
	98	*/
	99	if (likely(PageSwapCache(page))) {
	100	struct swap_info_struct *sis;
	101
	102	sis = page_swap_info(page);
	103	if (sis->flags & SWP_BLKDEV) {
	104	/*
	105	* The swap subsystem performs lazy swap slot freeing,
	106	* expecting that the page will be swapped out again.
	107	* So we can avoid an unnecessary write if the page
	108	* isn't redirtied.
	109	* This is good for real swap storage because we can
	110	* reduce unnecessary I/O and enhance wear-leveling
	111	* if an SSD is used as the as swap device.
	112	* But if in-memory swap device (eg zram) is used,
	113	* this causes a duplicated copy between uncompressed
	114	* data in VM-owned memory and compressed data in
	115	* zram-owned memory. So let's free zram-owned memory
	116	* and make the VM-owned decompressed page dirty,
	117	* so the page should be swapped out somewhere again if
	118	* we again wish to reclaim it.
	119	*/
	120	struct gendisk *disk = sis->bdev->bd_disk;
	121	if (disk->fops->swap_slot_free_notify) {
	122	swp_entry_t entry;
	123	unsigned long offset;
	124
	125	entry.val = page_private(page);
	126	offset = swp_offset(entry);
	127
	128	SetPageDirty(page);
	129	disk->fops->swap_slot_free_notify(sis->bdev,
	130	offset);
	131	}
	132	}
1da177e4	133	}
6fa3eb70 S	134
6fa3eb70 S	135	out:
1da177e4 LT	136	unlock_page(page);
1da177e4 LT	137	bio_put(bio);
1da177e4 LT	138	}
1da177e4 LT	139
a509bc1a MG	140	int generic_swapfile_activate(struct swap_info_struct *sis,
	141	struct file *swap_file,
	142	sector_t *span)
	143	{
	144	struct address_space *mapping = swap_file->f_mapping;
	145	struct inode *inode = mapping->host;
	146	unsigned blocks_per_page;
	147	unsigned long page_no;
	148	unsigned blkbits;
	149	sector_t probe_block;
	150	sector_t last_block;
	151	sector_t lowest_block = -1;
	152	sector_t highest_block = 0;
	153	int nr_extents = 0;
	154	int ret;
	155
	156	blkbits = inode->i_blkbits;
	157	blocks_per_page = PAGE_SIZE >> blkbits;
	158
	159	/*
	160	* Map all the blocks into the extent list. This code doesn't try
	161	* to be very smart.
	162	*/
	163	probe_block = 0;
	164	page_no = 0;
	165	last_block = i_size_read(inode) >> blkbits;
	166	while ((probe_block + blocks_per_page) <= last_block &&
	167	page_no < sis->max) {
	168	unsigned block_in_page;
	169	sector_t first_block;
	170
	171	first_block = bmap(inode, probe_block);
	172	if (first_block == 0)
	173	goto bad_bmap;
	174
	175	/*
	176	* It must be PAGE_SIZE aligned on-disk
	177	*/
	178	if (first_block & (blocks_per_page - 1)) {
	179	probe_block++;
	180	goto reprobe;
	181	}
	182
	183	for (block_in_page = 1; block_in_page < blocks_per_page;
	184	block_in_page++) {
	185	sector_t block;
	186
	187	block = bmap(inode, probe_block + block_in_page);
	188	if (block == 0)
	189	goto bad_bmap;
	190	if (block != first_block + block_in_page) {
	191	/* Discontiguity */
	192	probe_block++;
	193	goto reprobe;
	194	}
	195	}
	196
	197	first_block >>= (PAGE_SHIFT - blkbits);
	198	if (page_no) { /* exclude the header page */
	199	if (first_block < lowest_block)
	200	lowest_block = first_block;
	201	if (first_block > highest_block)
	202	highest_block = first_block;
	203	}
204
205	/*
206	* We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
207	*/
208	ret = add_swap_extent(sis, page_no, 1, first_block);
209	if (ret < 0)
210	goto out;
211	nr_extents += ret;
212	page_no++;
213	probe_block += blocks_per_page;
214	reprobe:
215	continue;
216	}
217	ret = nr_extents;
218	*span = 1 + highest_block - lowest_block;
219	if (page_no == 0)
220	page_no = 1; /* force Empty message */
221	sis->max = page_no;
222	sis->pages = page_no - 1;
223	sis->highest_bit = page_no - 1;
224	out:
225	return ret;
226	bad_bmap:
227	printk(KERN_ERR "swapon: swapfile has holes\n");
228	ret = -EINVAL;
229	goto out;
230	}
231
1da177e4 LT	232	/*
	233	* We may have stale swap cache pages in memory: notice
	234	* them here and get rid of the unnecessary final write.
	235	*/
	236	int swap_writepage(struct page page, struct writeback_control wbc)
	237	{
2f772e6c	238	int ret = 0;
1da177e4	239
a2c43eed	240	if (try_to_free_swap(page)) {
1da177e4 LT	241	unlock_page(page);
	242	goto out;
	243	}
165c8aed	244	if (frontswap_store(page) == 0) {
38b5faf4 DM	245	set_page_writeback(page);
	246	unlock_page(page);
	247	end_page_writeback(page);
	248	goto out;
	249	}
1eec6702	250	ret = __swap_writepage(page, wbc, end_swap_bio_write);
2f772e6c SJ	251	out:
	252	return ret;
	253	}
	254
1eec6702 SJ	255	int __swap_writepage(struct page page, struct writeback_control wbc,
1eec6702 SJ	256	void (end_write_func)(struct bio , int))
2f772e6c SJ	257	{
	258	struct bio *bio;
	259	int ret = 0, rw = WRITE;
	260	struct swap_info_struct *sis = page_swap_info(page);
62c230bc MG	261
	262	if (sis->flags & SWP_FILE) {
	263	struct kiocb kiocb;
	264	struct file *swap_file = sis->swap_file;
	265	struct address_space *mapping = swap_file->f_mapping;
	266	struct iovec iov = {
5a178119	267	.iov_base = kmap(page),
62c230bc MG	268	.iov_len = PAGE_SIZE,
	269	};
	270
	271	init_sync_kiocb(&kiocb, swap_file);
	272	kiocb.ki_pos = page_file_offset(page);
	273	kiocb.ki_left = PAGE_SIZE;
	274	kiocb.ki_nbytes = PAGE_SIZE;
	275
0cdc444a	276	set_page_writeback(page);
62c230bc MG	277	unlock_page(page);
	278	ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
	279	&kiocb, &iov,
	280	kiocb.ki_pos, 1);
5a178119	281	kunmap(page);
62c230bc MG	282	if (ret == PAGE_SIZE) {
	283	count_vm_event(PSWPOUT);
	284	ret = 0;
2d30d31e	285	} else {
0cdc444a MG	286	/*
	287	* In the case of swap-over-nfs, this can be a
	288	* temporary failure if the system has limited
	289	* memory for allocating transmit buffers.
	290	* Mark the page dirty and avoid
	291	* rotate_reclaimable_page but rate-limit the
	292	* messages but do not flag PageError like
	293	* the normal direct-to-bio case as it could
	294	* be temporary.
	295	*/
2d30d31e	296	set_page_dirty(page);
0cdc444a MG	297	ClearPageReclaim(page);
	298	pr_err_ratelimited("Write error on dio swapfile (%Lu)\n",
	299	page_file_offset(page));
62c230bc	300	}
0cdc444a	301	end_page_writeback(page);
62c230bc MG	302	return ret;
	303	}
	304
1eec6702	305	bio = get_swap_bio(GFP_NOIO, page, end_write_func);
1da177e4 LT	306	if (bio == NULL) {
	307	set_page_dirty(page);
	308	unlock_page(page);
	309	ret = -ENOMEM;
	310	goto out;
	311	}
	312	if (wbc->sync_mode == WB_SYNC_ALL)
721a9602	313	rw \|= REQ_SYNC;
6fa3eb70 S	314
	315	#ifdef CONFIG_ZRAM
	316	current->swap_out++;
	317	#endif
f8891e5e	318	count_vm_event(PSWPOUT);
1da177e4 LT	319	set_page_writeback(page);
	320	unlock_page(page);
	321	submit_bio(rw, bio);
	322	out:
	323	return ret;
	324	}
	325
aca8bf32	326	int swap_readpage(struct page *page)
1da177e4 LT	327	{
	328	struct bio *bio;
	329	int ret = 0;
62c230bc	330	struct swap_info_struct *sis = page_swap_info(page);
1da177e4	331
51726b12 HD	332	VM_BUG_ON(!PageLocked(page));
51726b12 HD	333	VM_BUG_ON(PageUptodate(page));
165c8aed	334	if (frontswap_load(page) == 0) {
38b5faf4 DM	335	SetPageUptodate(page);
	336	unlock_page(page);
	337	goto out;
	338	}
62c230bc MG	339
	340	if (sis->flags & SWP_FILE) {
	341	struct file *swap_file = sis->swap_file;
	342	struct address_space *mapping = swap_file->f_mapping;
	343
	344	ret = mapping->a_ops->readpage(swap_file, page);
6fa3eb70 S	345	if (!ret) {
	346	#ifdef CONFIG_ZRAM
	347	current->swap_in++;
	348	#endif
62c230bc	349	count_vm_event(PSWPIN);
6fa3eb70	350	}
62c230bc MG	351	return ret;
	352	}
	353
f29ad6a9	354	bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
1da177e4 LT	355	if (bio == NULL) {
	356	unlock_page(page);
	357	ret = -ENOMEM;
	358	goto out;
	359	}
6fa3eb70 S	360
	361	#ifdef CONFIG_ZRAM
	362	current->swap_in++;
	363	#endif
f8891e5e	364	count_vm_event(PSWPIN);
1da177e4 LT	365	submit_bio(READ, bio);
	366	out:
	367	return ret;
	368	}
62c230bc MG	369
	370	int swap_set_page_dirty(struct page *page)
	371	{
	372	struct swap_info_struct *sis = page_swap_info(page);
	373
	374	if (sis->flags & SWP_FILE) {
	375	struct address_space *mapping = sis->swap_file->f_mapping;
	376	return mapping->a_ops->set_page_dirty(page);
	377	} else {
	378	return __set_page_dirty_no_writeback(page);
	379	}
	380	}