[linux-2.6-block.git] / fs / erofs / data.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017-2018 HUAWEI, Inc.
 *             http://www.huawei.com/
 * Created by Gao Xiang <gaoxiang25@huawei.com>
 */
#include "internal.h"
#include <linux/prefetch.h>

#include <trace/events/erofs.h>

static void erofs_readendio(struct bio *bio)
{
	struct bio_vec *bvec;
	blk_status_t err = bio->bi_status;
	struct bvec_iter_all iter_all;

	bio_for_each_segment_all(bvec, bio, iter_all) {
		struct page *page = bvec->bv_page;

		/* page is already locked */
		DBG_BUGON(PageUptodate(page));

		if (err)
			SetPageError(page);
		else
			SetPageUptodate(page);

		unlock_page(page);
		/* page could be reclaimed now */
	}
	bio_put(bio);
}

struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr)
{
	struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
	struct page *page;

	page = read_cache_page_gfp(mapping, blkaddr,
				   mapping_gfp_constraint(mapping, ~__GFP_FS));
	/* should already be PageUptodate */
	if (!IS_ERR(page))
		lock_page(page);
	return page;
}

static int erofs_map_blocks_flatmode(struct inode *inode,
				     struct erofs_map_blocks *map,
				     int flags)
{
	int err = 0;
	erofs_blk_t nblocks, lastblk;
	u64 offset = map->m_la;
	struct erofs_inode *vi = EROFS_I(inode);
	bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);

	trace_erofs_map_blocks_flatmode_enter(inode, map, flags);

	nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
	lastblk = nblocks - tailendpacking;

	if (offset >= inode->i_size) {
		/* leave out-of-bound access unmapped */
		map->m_flags = 0;
		map->m_plen = 0;
		goto out;
	}

	/* there is no hole in flatmode */
	map->m_flags = EROFS_MAP_MAPPED;

	if (offset < blknr_to_addr(lastblk)) {
		map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
		map->m_plen = blknr_to_addr(lastblk) - offset;
	} else if (tailendpacking) {
		/* 2 - inode inline B: inode, [xattrs], inline last blk... */
		struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);

		map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize +
			vi->xattr_isize + erofs_blkoff(map->m_la);
		map->m_plen = inode->i_size - offset;

		/* inline data should be located in one meta block */
		if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
			erofs_err(inode->i_sb,
				  "inline data cross block boundary @ nid %llu",
				  vi->nid);
			DBG_BUGON(1);
			err = -EFSCORRUPTED;
			goto err_out;
		}

		map->m_flags |= EROFS_MAP_META;
	} else {
		erofs_err(inode->i_sb,
			  "internal error @ nid: %llu (size %llu), m_la 0x%llx",
			  vi->nid, inode->i_size, map->m_la);
		DBG_BUGON(1);
		err = -EIO;
		goto err_out;
	}

out:
	map->m_llen = map->m_plen;

err_out:
	trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
	return err;
}

int erofs_map_blocks(struct inode *inode,
		     struct erofs_map_blocks *map, int flags)
{
	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
		int err = z_erofs_map_blocks_iter(inode, map, flags);

		if (map->mpage) {
			put_page(map->mpage);
			map->mpage = NULL;
		}
		return err;
	}
	return erofs_map_blocks_flatmode(inode, map, flags);
}

static inline struct bio *erofs_read_raw_page(struct bio *bio,
					      struct address_space *mapping,
					      struct page *page,
					      erofs_off_t *last_block,
					      unsigned int nblocks,
					      bool ra)
{
	struct inode *const inode = mapping->host;
	struct super_block *const sb = inode->i_sb;
	erofs_off_t current_block = (erofs_off_t)page->index;
	int err;

	DBG_BUGON(!nblocks);

	if (PageUptodate(page)) {
		err = 0;
		goto has_updated;
	}

	/* note that for readpage case, bio also equals to NULL */
	if (bio &&
	    /* not continuous */
	    *last_block + 1 != current_block) {
submit_bio_retry:
		submit_bio(bio);
		bio = NULL;
	}

	if (!bio) {
		struct erofs_map_blocks map = {
			.m_la = blknr_to_addr(current_block),
		};
		erofs_blk_t blknr;
		unsigned int blkoff;

		err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
		if (err)
			goto err_out;

		/* zero out the holed page */
		if (!(map.m_flags & EROFS_MAP_MAPPED)) {
			zero_user_segment(page, 0, PAGE_SIZE);
			SetPageUptodate(page);

			/* imply err = 0, see erofs_map_blocks */
			goto has_updated;
		}

		/* for RAW access mode, m_plen must be equal to m_llen */
		DBG_BUGON(map.m_plen != map.m_llen);

		blknr = erofs_blknr(map.m_pa);
		blkoff = erofs_blkoff(map.m_pa);

		/* deal with inline page */
		if (map.m_flags & EROFS_MAP_META) {
			void *vsrc, *vto;
			struct page *ipage;

			DBG_BUGON(map.m_plen > PAGE_SIZE);

			ipage = erofs_get_meta_page(inode->i_sb, blknr);

			if (IS_ERR(ipage)) {
				err = PTR_ERR(ipage);
				goto err_out;
			}

			vsrc = kmap_atomic(ipage);
			vto = kmap_atomic(page);
			memcpy(vto, vsrc + blkoff, map.m_plen);
			memset(vto + map.m_plen, 0, PAGE_SIZE - map.m_plen);
			kunmap_atomic(vto);
			kunmap_atomic(vsrc);
			flush_dcache_page(page);

			SetPageUptodate(page);
			/* TODO: could we unlock the page earlier? */
			unlock_page(ipage);
			put_page(ipage);

			/* imply err = 0, see erofs_map_blocks */
			goto has_updated;
		}

		/* pa must be block-aligned for raw reading */
		DBG_BUGON(erofs_blkoff(map.m_pa));

		/* max # of continuous pages */
		if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE))
			nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE);
		if (nblocks > BIO_MAX_PAGES)
			nblocks = BIO_MAX_PAGES;

		bio = bio_alloc(GFP_NOIO, nblocks);

		bio->bi_end_io = erofs_readendio;
		bio_set_dev(bio, sb->s_bdev);
		bio->bi_iter.bi_sector = (sector_t)blknr <<
			LOG_SECTORS_PER_BLOCK;
		bio->bi_opf = REQ_OP_READ;
	}

	err = bio_add_page(bio, page, PAGE_SIZE, 0);
	/* out of the extent or bio is full */
	if (err < PAGE_SIZE)
		goto submit_bio_retry;

	*last_block = current_block;

	/* shift in advance in case of it followed by too many gaps */
	if (bio->bi_iter.bi_size >= bio->bi_max_vecs * PAGE_SIZE) {
		/* err should reassign to 0 after submitting */
		err = 0;
		goto submit_bio_out;
	}

	return bio;

err_out:
	/* for sync reading, set page error immediately */
	if (!ra) {
		SetPageError(page);
		ClearPageUptodate(page);
	}
has_updated:
	unlock_page(page);

	/* if updated manually, continuous pages has a gap */
	if (bio)
submit_bio_out:
		submit_bio(bio);
	return err ? ERR_PTR(err) : NULL;
}

/*
 * since we dont have write or truncate flows, so no inode
 * locking needs to be held at the moment.
 */
static int erofs_raw_access_readpage(struct file *file, struct page *page)
{
	erofs_off_t last_block;
	struct bio *bio;

	trace_erofs_readpage(page, true);

	bio = erofs_read_raw_page(NULL, page->mapping,
				  page, &last_block, 1, false);

	if (IS_ERR(bio))
		return PTR_ERR(bio);

	DBG_BUGON(bio);	/* since we have only one bio -- must be NULL */
	return 0;
}

static int erofs_raw_access_readpages(struct file *filp,
				      struct address_space *mapping,
				      struct list_head *pages,
				      unsigned int nr_pages)
{
	erofs_off_t last_block;
	struct bio *bio = NULL;
	gfp_t gfp = readahead_gfp_mask(mapping);
	struct page *page = list_last_entry(pages, struct page, lru);

	trace_erofs_readpages(mapping->host, page, nr_pages, true);

	for (; nr_pages; --nr_pages) {
		page = list_entry(pages->prev, struct page, lru);

		prefetchw(&page->flags);
		list_del(&page->lru);

		if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) {
			bio = erofs_read_raw_page(bio, mapping, page,
						  &last_block, nr_pages, true);

			/* all the page errors are ignored when readahead */
			if (IS_ERR(bio)) {
				pr_err("%s, readahead error at page %lu of nid %llu\n",
				       __func__, page->index,
				       EROFS_I(mapping->host)->nid);

				bio = NULL;
			}
		}

		/* pages could still be locked */
		put_page(page);
	}
	DBG_BUGON(!list_empty(pages));

	/* the rare case (end in gaps) */
	if (bio)
		submit_bio(bio);
	return 0;
}

static int erofs_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh, int create)
{
	struct erofs_map_blocks map = {
		.m_la = iblock << 9,
	};
	int err;

	err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
	if (err)
		return err;

	if (map.m_flags & EROFS_MAP_MAPPED)
		bh->b_blocknr = erofs_blknr(map.m_pa);

	return err;
}

static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
{
	struct inode *inode = mapping->host;

	if (EROFS_I(inode)->datalayout == EROFS_INODE_FLAT_INLINE) {
		erofs_blk_t blks = i_size_read(inode) >> LOG_BLOCK_SIZE;

		if (block >> LOG_SECTORS_PER_BLOCK >= blks)
			return 0;
	}

	return generic_block_bmap(mapping, block, erofs_get_block);
}

/* for uncompressed (aligned) files and raw access for other files */
const struct address_space_operations erofs_raw_access_aops = {
	.readpage = erofs_raw_access_readpage,
	.readpages = erofs_raw_access_readpages,
	.bmap = erofs_bmap,
};
Commit	Line	Data
29b24f6c	1	// SPDX-License-Identifier: GPL-2.0-only
81781b02	2	/*
81781b02 GX	3	* Copyright (C) 2017-2018 HUAWEI, Inc.
	4	* http://www.huawei.com/
	5	* Created by Gao Xiang <gaoxiang25@huawei.com>
81781b02 GX	6	*/
	7	#include "internal.h"
	8	#include <linux/prefetch.h>
	9
13f06f48 CY	10	#include <trace/events/erofs.h>
13f06f48 CY	11
99634bf3	12	static void erofs_readendio(struct bio *bio)
81781b02	13	{
81781b02	14	struct bio_vec *bvec;
14a56ec6	15	blk_status_t err = bio->bi_status;
6dc4f100	16	struct bvec_iter_all iter_all;
81781b02	17
2b070cfe	18	bio_for_each_segment_all(bvec, bio, iter_all) {
81781b02 GX	19	struct page *page = bvec->bv_page;
	20
	21	/* page is already locked */
9141b60c	22	DBG_BUGON(PageUptodate(page));
81781b02	23
8d8a09b0	24	if (err)
81781b02 GX	25	SetPageError(page);
	26	else
	27	SetPageUptodate(page);
	28
	29	unlock_page(page);
	30	/* page could be reclaimed now */
	31	}
	32	bio_put(bio);
	33	}
	34
e655b5b3	35	struct page erofs_get_meta_page(struct super_block sb, erofs_blk_t blkaddr)
81781b02	36	{
55252ab7 GX	37	struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
55252ab7 GX	38	struct page *page;
6e78901a	39
55252ab7	40	page = read_cache_page_gfp(mapping, blkaddr,
618f40ea	41	mapping_gfp_constraint(mapping, ~__GFP_FS));
55252ab7 GX	42	/* should already be PageUptodate */
	43	if (!IS_ERR(page))
	44	lock_page(page);
	45	return page;
81781b02 GX	46	}
	47
	48	static int erofs_map_blocks_flatmode(struct inode *inode,
f0950b02 BD	49	struct erofs_map_blocks *map,
f0950b02 BD	50	int flags)
81781b02	51	{
9141b60c	52	int err = 0;
81781b02 GX	53	erofs_blk_t nblocks, lastblk;
81781b02 GX	54	u64 offset = map->m_la;
a5876e24	55	struct erofs_inode *vi = EROFS_I(inode);
8a765682	56	bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
81781b02	57
13f06f48	58	trace_erofs_map_blocks_flatmode_enter(inode, map, flags);
81781b02 GX	59
81781b02 GX	60	nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
8a765682	61	lastblk = nblocks - tailendpacking;
81781b02	62
8d8a09b0	63	if (offset >= inode->i_size) {
81781b02 GX	64	/* leave out-of-bound access unmapped */
	65	map->m_flags = 0;
	66	map->m_plen = 0;
	67	goto out;
	68	}
	69
	70	/* there is no hole in flatmode */
	71	map->m_flags = EROFS_MAP_MAPPED;
	72
	73	if (offset < blknr_to_addr(lastblk)) {
	74	map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
	75	map->m_plen = blknr_to_addr(lastblk) - offset;
8a765682	76	} else if (tailendpacking) {
81781b02 GX	77	/* 2 - inode inline B: inode, [xattrs], inline last blk... */
	78	struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
	79
	80	map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize +
	81	vi->xattr_isize + erofs_blkoff(map->m_la);
	82	map->m_plen = inode->i_size - offset;
	83
a6b9b1d5	84	/* inline data should be located in one meta block */
9141b60c	85	if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
4f761fa2 GX	86	erofs_err(inode->i_sb,
	87	"inline data cross block boundary @ nid %llu",
	88	vi->nid);
9141b60c	89	DBG_BUGON(1);
a6b9b1d5	90	err = -EFSCORRUPTED;
9141b60c CG	91	goto err_out;
	92	}
	93
81781b02 GX	94	map->m_flags \|= EROFS_MAP_META;
81781b02 GX	95	} else {
4f761fa2 GX	96	erofs_err(inode->i_sb,
	97	"internal error @ nid: %llu (size %llu), m_la 0x%llx",
	98	vi->nid, inode->i_size, map->m_la);
9141b60c CG	99	DBG_BUGON(1);
	100	err = -EIO;
	101	goto err_out;
81781b02 GX	102	}
	103
	104	out:
	105	map->m_llen = map->m_plen;
9141b60c CG	106
9141b60c CG	107	err_out:
13f06f48	108	trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
9141b60c	109	return err;
81781b02 GX	110	}
	111
	112	int erofs_map_blocks(struct inode *inode,
f0950b02	113	struct erofs_map_blocks *map, int flags)
81781b02	114	{
a5876e24	115	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
3b423417	116	int err = z_erofs_map_blocks_iter(inode, map, flags);
81781b02	117
3b423417 CY	118	if (map->mpage) {
	119	put_page(map->mpage);
	120	map->mpage = NULL;
	121	}
02827e17 GX	122	return err;
02827e17 GX	123	}
81781b02 GX	124	return erofs_map_blocks_flatmode(inode, map, flags);
	125	}
	126
f0950b02 BD	127	static inline struct bio erofs_read_raw_page(struct bio bio,
	128	struct address_space *mapping,
	129	struct page *page,
	130	erofs_off_t *last_block,
	131	unsigned int nblocks,
	132	bool ra)
81781b02	133	{
14a56ec6 GX	134	struct inode *const inode = mapping->host;
14a56ec6 GX	135	struct super_block *const sb = inode->i_sb;
81781b02 GX	136	erofs_off_t current_block = (erofs_off_t)page->index;
	137	int err;
	138
9141b60c	139	DBG_BUGON(!nblocks);
81781b02 GX	140
	141	if (PageUptodate(page)) {
	142	err = 0;
	143	goto has_updated;
	144	}
	145
81781b02	146	/* note that for readpage case, bio also equals to NULL */
d1ab8244	147	if (bio &&
f0950b02 BD	148	/* not continuous */
f0950b02 BD	149	*last_block + 1 != current_block) {
81781b02	150	submit_bio_retry:
94e4e153	151	submit_bio(bio);
81781b02 GX	152	bio = NULL;
	153	}
	154
d1ab8244	155	if (!bio) {
81781b02 GX	156	struct erofs_map_blocks map = {
	157	.m_la = blknr_to_addr(current_block),
	158	};
55441958	159	erofs_blk_t blknr;
7dd68b14	160	unsigned int blkoff;
81781b02 GX	161
81781b02 GX	162	err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
8d8a09b0	163	if (err)
81781b02 GX	164	goto err_out;
	165
	166	/* zero out the holed page */
8d8a09b0	167	if (!(map.m_flags & EROFS_MAP_MAPPED)) {
81781b02 GX	168	zero_user_segment(page, 0, PAGE_SIZE);
	169	SetPageUptodate(page);
	170
	171	/* imply err = 0, see erofs_map_blocks */
	172	goto has_updated;
	173	}
	174
	175	/* for RAW access mode, m_plen must be equal to m_llen */
9141b60c	176	DBG_BUGON(map.m_plen != map.m_llen);
81781b02	177
55441958 GX	178	blknr = erofs_blknr(map.m_pa);
	179	blkoff = erofs_blkoff(map.m_pa);
	180
81781b02 GX	181	/* deal with inline page */
	182	if (map.m_flags & EROFS_MAP_META) {
	183	void vsrc, vto;
	184	struct page *ipage;
	185
9141b60c	186	DBG_BUGON(map.m_plen > PAGE_SIZE);
81781b02	187
e655b5b3	188	ipage = erofs_get_meta_page(inode->i_sb, blknr);
81781b02 GX	189
	190	if (IS_ERR(ipage)) {
	191	err = PTR_ERR(ipage);
	192	goto err_out;
	193	}
	194
	195	vsrc = kmap_atomic(ipage);
	196	vto = kmap_atomic(page);
55441958	197	memcpy(vto, vsrc + blkoff, map.m_plen);
81781b02 GX	198	memset(vto + map.m_plen, 0, PAGE_SIZE - map.m_plen);
	199	kunmap_atomic(vto);
	200	kunmap_atomic(vsrc);
	201	flush_dcache_page(page);
	202
	203	SetPageUptodate(page);
	204	/* TODO: could we unlock the page earlier? */
	205	unlock_page(ipage);
	206	put_page(ipage);
	207
	208	/* imply err = 0, see erofs_map_blocks */
	209	goto has_updated;
	210	}
	211
	212	/* pa must be block-aligned for raw reading */
9141b60c	213	DBG_BUGON(erofs_blkoff(map.m_pa));
81781b02 GX	214
	215	/* max # of continuous pages */
	216	if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE))
	217	nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE);
	218	if (nblocks > BIO_MAX_PAGES)
	219	nblocks = BIO_MAX_PAGES;
	220
618f40ea GX	221	bio = bio_alloc(GFP_NOIO, nblocks);
	222
	223	bio->bi_end_io = erofs_readendio;
	224	bio_set_dev(bio, sb->s_bdev);
	225	bio->bi_iter.bi_sector = (sector_t)blknr <<
	226	LOG_SECTORS_PER_BLOCK;
	227	bio->bi_opf = REQ_OP_READ;
81781b02 GX	228	}
	229
	230	err = bio_add_page(bio, page, PAGE_SIZE, 0);
	231	/* out of the extent or bio is full */
	232	if (err < PAGE_SIZE)
	233	goto submit_bio_retry;
	234
	235	*last_block = current_block;
	236
	237	/* shift in advance in case of it followed by too many gaps */
f4e97f5d	238	if (bio->bi_iter.bi_size >= bio->bi_max_vecs * PAGE_SIZE) {
81781b02 GX	239	/* err should reassign to 0 after submitting */
	240	err = 0;
	241	goto submit_bio_out;
	242	}
	243
	244	return bio;
	245
	246	err_out:
	247	/* for sync reading, set page error immediately */
	248	if (!ra) {
	249	SetPageError(page);
	250	ClearPageUptodate(page);
	251	}
	252	has_updated:
	253	unlock_page(page);
	254
	255	/* if updated manually, continuous pages has a gap */
d1ab8244	256	if (bio)
81781b02	257	submit_bio_out:
94e4e153	258	submit_bio(bio);
8d8a09b0	259	return err ? ERR_PTR(err) : NULL;
81781b02 GX	260	}
	261
	262	/*
	263	* since we dont have write or truncate flows, so no inode
	264	* locking needs to be held at the moment.
	265	*/
	266	static int erofs_raw_access_readpage(struct file file, struct page page)
	267	{
	268	erofs_off_t last_block;
	269	struct bio *bio;
	270
13f06f48 CY	271	trace_erofs_readpage(page, true);
13f06f48 CY	272
81781b02	273	bio = erofs_read_raw_page(NULL, page->mapping,
f0950b02	274	page, &last_block, 1, false);
81781b02 GX	275
	276	if (IS_ERR(bio))
	277	return PTR_ERR(bio);
	278
9141b60c	279	DBG_BUGON(bio); /* since we have only one bio -- must be NULL */
81781b02 GX	280	return 0;
	281	}
	282
	283	static int erofs_raw_access_readpages(struct file *filp,
f0950b02 BD	284	struct address_space *mapping,
	285	struct list_head *pages,
	286	unsigned int nr_pages)
81781b02 GX	287	{
	288	erofs_off_t last_block;
	289	struct bio *bio = NULL;
	290	gfp_t gfp = readahead_gfp_mask(mapping);
13f06f48 CY	291	struct page *page = list_last_entry(pages, struct page, lru);
	292
	293	trace_erofs_readpages(mapping->host, page, nr_pages, true);
81781b02 GX	294
81781b02 GX	295	for (; nr_pages; --nr_pages) {
13f06f48	296	page = list_entry(pages->prev, struct page, lru);
81781b02 GX	297
	298	prefetchw(&page->flags);
	299	list_del(&page->lru);
	300
	301	if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) {
	302	bio = erofs_read_raw_page(bio, mapping, page,
f0950b02	303	&last_block, nr_pages, true);
81781b02 GX	304
	305	/* all the page errors are ignored when readahead */
	306	if (IS_ERR(bio)) {
	307	pr_err("%s, readahead error at page %lu of nid %llu\n",
f0950b02	308	__func__, page->index,
a5876e24	309	EROFS_I(mapping->host)->nid);
81781b02 GX	310
	311	bio = NULL;
	312	}
	313	}
	314
	315	/* pages could still be locked */
	316	put_page(page);
	317	}
9141b60c	318	DBG_BUGON(!list_empty(pages));
81781b02 GX	319
81781b02 GX	320	/* the rare case (end in gaps) */
8d8a09b0	321	if (bio)
94e4e153	322	submit_bio(bio);
81781b02 GX	323	return 0;
	324	}
	325
9da681e0 CY	326	static int erofs_get_block(struct inode *inode, sector_t iblock,
	327	struct buffer_head *bh, int create)
	328	{
	329	struct erofs_map_blocks map = {
	330	.m_la = iblock << 9,
	331	};
	332	int err;
	333
	334	err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
	335	if (err)
	336	return err;
	337
	338	if (map.m_flags & EROFS_MAP_MAPPED)
	339	bh->b_blocknr = erofs_blknr(map.m_pa);
	340
	341	return err;
	342	}
	343
	344	static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
	345	{
	346	struct inode *inode = mapping->host;
	347
a5876e24	348	if (EROFS_I(inode)->datalayout == EROFS_INODE_FLAT_INLINE) {
9da681e0 CY	349	erofs_blk_t blks = i_size_read(inode) >> LOG_BLOCK_SIZE;
	350
	351	if (block >> LOG_SECTORS_PER_BLOCK >= blks)
	352	return 0;
	353	}
	354
	355	return generic_block_bmap(mapping, block, erofs_get_block);
	356	}
	357
81781b02 GX	358	/* for uncompressed (aligned) files and raw access for other files */
	359	const struct address_space_operations erofs_raw_access_aops = {
	360	.readpage = erofs_raw_access_readpage,
	361	.readpages = erofs_raw_access_readpages,
9da681e0	362	.bmap = erofs_bmap,
81781b02 GX	363	};
81781b02 GX	364