[thirdparty/linux.git] / fs / erofs / data.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017-2018 HUAWEI, Inc.
 *             https://www.huawei.com/
 * Copyright (C) 2021, Alibaba Cloud
 */
#include "internal.h"
#include <linux/prefetch.h>
#include <linux/sched/mm.h>
#include <linux/dax.h>
#include <trace/events/erofs.h>

void erofs_unmap_metabuf(struct erofs_buf *buf)
{
	if (buf->kmap_type == EROFS_KMAP)
		kunmap_local(buf->base);
	buf->base = NULL;
	buf->kmap_type = EROFS_NO_KMAP;
}

void erofs_put_metabuf(struct erofs_buf *buf)
{
	if (!buf->page)
		return;
	erofs_unmap_metabuf(buf);
	put_page(buf->page);
	buf->page = NULL;
}

void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
		  erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
	struct address_space *const mapping = inode->i_mapping;
	erofs_off_t offset = blknr_to_addr(blkaddr);
	pgoff_t index = offset >> PAGE_SHIFT;
	struct page *page = buf->page;
	struct folio *folio;
	unsigned int nofs_flag;

	if (!page || page->index != index) {
		erofs_put_metabuf(buf);

		nofs_flag = memalloc_nofs_save();
		folio = read_cache_folio(mapping, index, NULL, NULL);
		memalloc_nofs_restore(nofs_flag);
		if (IS_ERR(folio))
			return folio;

		/* should already be PageUptodate, no need to lock page */
		page = folio_file_page(folio, index);
		buf->page = page;
	}
	if (buf->kmap_type == EROFS_NO_KMAP) {
		if (type == EROFS_KMAP)
			buf->base = kmap_local_page(page);
		buf->kmap_type = type;
	} else if (buf->kmap_type != type) {
		DBG_BUGON(1);
		return ERR_PTR(-EFAULT);
	}
	if (type == EROFS_NO_KMAP)
		return NULL;
	return buf->base + (offset & ~PAGE_MASK);
}

void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
			 erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
	if (erofs_is_fscache_mode(sb))
		return erofs_bread(buf, EROFS_SB(sb)->s_fscache->inode,
				   blkaddr, type);

	return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type);
}

static int erofs_map_blocks_flatmode(struct inode *inode,
				     struct erofs_map_blocks *map)
{
	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);

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

	/* 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) {
		map->m_pa = erofs_iloc(inode) + vi->inode_isize +
			vi->xattr_isize + erofs_blkoff(offset);
		map->m_plen = inode->i_size - offset;

		/* inline data should be located in the same meta block */
		if (erofs_blkoff(map->m_pa) + map->m_plen > EROFS_BLKSIZ) {
			erofs_err(inode->i_sb,
				  "inline data cross block boundary @ nid %llu",
				  vi->nid);
			DBG_BUGON(1);
			return -EFSCORRUPTED;
		}
		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);
		return -EIO;
	}
	return 0;
}

int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map)
{
	struct super_block *sb = inode->i_sb;
	struct erofs_inode *vi = EROFS_I(inode);
	struct erofs_inode_chunk_index *idx;
	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
	u64 chunknr;
	unsigned int unit;
	erofs_off_t pos;
	void *kaddr;
	int err = 0;

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

	if (vi->datalayout != EROFS_INODE_CHUNK_BASED) {
		err = erofs_map_blocks_flatmode(inode, map);
		goto out;
	}

	if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
		unit = sizeof(*idx);			/* chunk index */
	else
		unit = EROFS_BLOCK_MAP_ENTRY_SIZE;	/* block map */

	chunknr = map->m_la >> vi->chunkbits;
	pos = ALIGN(erofs_iloc(inode) + vi->inode_isize +
		    vi->xattr_isize, unit) + unit * chunknr;

	kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP);
	if (IS_ERR(kaddr)) {
		err = PTR_ERR(kaddr);
		goto out;
	}
	map->m_la = chunknr << vi->chunkbits;
	map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits,
			    roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));

	/* handle block map */
	if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
		__le32 *blkaddr = kaddr + erofs_blkoff(pos);

		if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
			map->m_flags = 0;
		} else {
			map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr));
			map->m_flags = EROFS_MAP_MAPPED;
		}
		goto out_unlock;
	}
	/* parse chunk indexes */
	idx = kaddr + erofs_blkoff(pos);
	switch (le32_to_cpu(idx->blkaddr)) {
	case EROFS_NULL_ADDR:
		map->m_flags = 0;
		break;
	default:
		map->m_deviceid = le16_to_cpu(idx->device_id) &
			EROFS_SB(sb)->device_id_mask;
		map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr));
		map->m_flags = EROFS_MAP_MAPPED;
		break;
	}
out_unlock:
	erofs_put_metabuf(&buf);
out:
	if (!err)
		map->m_llen = map->m_plen;
	trace_erofs_map_blocks_exit(inode, map, 0, err);
	return err;
}

int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
{
	struct erofs_dev_context *devs = EROFS_SB(sb)->devs;
	struct erofs_device_info *dif;
	int id;

	/* primary device by default */
	map->m_bdev = sb->s_bdev;
	map->m_daxdev = EROFS_SB(sb)->dax_dev;
	map->m_dax_part_off = EROFS_SB(sb)->dax_part_off;
	map->m_fscache = EROFS_SB(sb)->s_fscache;

	if (map->m_deviceid) {
		down_read(&devs->rwsem);
		dif = idr_find(&devs->tree, map->m_deviceid - 1);
		if (!dif) {
			up_read(&devs->rwsem);
			return -ENODEV;
		}
		map->m_bdev = dif->bdev;
		map->m_daxdev = dif->dax_dev;
		map->m_dax_part_off = dif->dax_part_off;
		map->m_fscache = dif->fscache;
		up_read(&devs->rwsem);
	} else if (devs->extra_devices) {
		down_read(&devs->rwsem);
		idr_for_each_entry(&devs->tree, dif, id) {
			erofs_off_t startoff, length;

			if (!dif->mapped_blkaddr)
				continue;
			startoff = blknr_to_addr(dif->mapped_blkaddr);
			length = blknr_to_addr(dif->blocks);

			if (map->m_pa >= startoff &&
			    map->m_pa < startoff + length) {
				map->m_pa -= startoff;
				map->m_bdev = dif->bdev;
				map->m_daxdev = dif->dax_dev;
				map->m_dax_part_off = dif->dax_part_off;
				map->m_fscache = dif->fscache;
				break;
			}
		}
		up_read(&devs->rwsem);
	}
	return 0;
}

static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
		unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
{
	int ret;
	struct erofs_map_blocks map;
	struct erofs_map_dev mdev;

	map.m_la = offset;
	map.m_llen = length;

	ret = erofs_map_blocks(inode, &map);
	if (ret < 0)
		return ret;

	mdev = (struct erofs_map_dev) {
		.m_deviceid = map.m_deviceid,
		.m_pa = map.m_pa,
	};
	ret = erofs_map_dev(inode->i_sb, &mdev);
	if (ret)
		return ret;

	iomap->offset = map.m_la;
	if (flags & IOMAP_DAX)
		iomap->dax_dev = mdev.m_daxdev;
	else
		iomap->bdev = mdev.m_bdev;
	iomap->length = map.m_llen;
	iomap->flags = 0;
	iomap->private = NULL;

	if (!(map.m_flags & EROFS_MAP_MAPPED)) {
		iomap->type = IOMAP_HOLE;
		iomap->addr = IOMAP_NULL_ADDR;
		if (!iomap->length)
			iomap->length = length;
		return 0;
	}

	if (map.m_flags & EROFS_MAP_META) {
		void *ptr;
		struct erofs_buf buf = __EROFS_BUF_INITIALIZER;

		iomap->type = IOMAP_INLINE;
		ptr = erofs_read_metabuf(&buf, inode->i_sb,
					 erofs_blknr(mdev.m_pa), EROFS_KMAP);
		if (IS_ERR(ptr))
			return PTR_ERR(ptr);
		iomap->inline_data = ptr + erofs_blkoff(mdev.m_pa);
		iomap->private = buf.base;
	} else {
		iomap->type = IOMAP_MAPPED;
		iomap->addr = mdev.m_pa;
		if (flags & IOMAP_DAX)
			iomap->addr += mdev.m_dax_part_off;
	}
	return 0;
}

static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
		ssize_t written, unsigned int flags, struct iomap *iomap)
{
	void *ptr = iomap->private;

	if (ptr) {
		struct erofs_buf buf = {
			.page = kmap_to_page(ptr),
			.base = ptr,
			.kmap_type = EROFS_KMAP,
		};

		DBG_BUGON(iomap->type != IOMAP_INLINE);
		erofs_put_metabuf(&buf);
	} else {
		DBG_BUGON(iomap->type == IOMAP_INLINE);
	}
	return written;
}

static const struct iomap_ops erofs_iomap_ops = {
	.iomap_begin = erofs_iomap_begin,
	.iomap_end = erofs_iomap_end,
};

int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		 u64 start, u64 len)
{
	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
#ifdef CONFIG_EROFS_FS_ZIP
		return iomap_fiemap(inode, fieinfo, start, len,
				    &z_erofs_iomap_report_ops);
#else
		return -EOPNOTSUPP;
#endif
	}
	return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops);
}

/*
 * since we dont have write or truncate flows, so no inode
 * locking needs to be held at the moment.
 */
static int erofs_read_folio(struct file *file, struct folio *folio)
{
	return iomap_read_folio(folio, &erofs_iomap_ops);
}

static void erofs_readahead(struct readahead_control *rac)
{
	return iomap_readahead(rac, &erofs_iomap_ops);
}

static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
{
	return iomap_bmap(mapping, block, &erofs_iomap_ops);
}

static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct inode *inode = file_inode(iocb->ki_filp);

	/* no need taking (shared) inode lock since it's a ro filesystem */
	if (!iov_iter_count(to))
		return 0;

#ifdef CONFIG_FS_DAX
	if (IS_DAX(inode))
		return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
#endif
	if (iocb->ki_flags & IOCB_DIRECT) {
		struct block_device *bdev = inode->i_sb->s_bdev;
		unsigned int blksize_mask;

		if (bdev)
			blksize_mask = bdev_logical_block_size(bdev) - 1;
		else
			blksize_mask = i_blocksize(inode) - 1;

		if ((iocb->ki_pos | iov_iter_count(to) |
		     iov_iter_alignment(to)) & blksize_mask)
			return -EINVAL;

		return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
				    NULL, 0, NULL, 0);
	}
	return filemap_read(iocb, to, 0);
}

/* for uncompressed (aligned) files and raw access for other files */
const struct address_space_operations erofs_raw_access_aops = {
	.read_folio = erofs_read_folio,
	.readahead = erofs_readahead,
	.bmap = erofs_bmap,
	.direct_IO = noop_direct_IO,
	.release_folio = iomap_release_folio,
	.invalidate_folio = iomap_invalidate_folio,
};

#ifdef CONFIG_FS_DAX
static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf,
		enum page_entry_size pe_size)
{
	return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops);
}

static vm_fault_t erofs_dax_fault(struct vm_fault *vmf)
{
	return erofs_dax_huge_fault(vmf, PE_SIZE_PTE);
}

static const struct vm_operations_struct erofs_dax_vm_ops = {
	.fault		= erofs_dax_fault,
	.huge_fault	= erofs_dax_huge_fault,
};

static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	if (!IS_DAX(file_inode(file)))
		return generic_file_readonly_mmap(file, vma);

	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
		return -EINVAL;

	vma->vm_ops = &erofs_dax_vm_ops;
	vm_flags_set(vma, VM_HUGEPAGE);
	return 0;
}
#else
#define erofs_file_mmap	generic_file_readonly_mmap
#endif

const struct file_operations erofs_file_fops = {
	.llseek		= generic_file_llseek,
	.read_iter	= erofs_file_read_iter,
	.mmap		= erofs_file_mmap,
	.splice_read	= generic_file_splice_read,
};
Commit	Line	Data
29b24f6c	1	// SPDX-License-Identifier: GPL-2.0-only
81781b02	2	/*
81781b02	3	* Copyright (C) 2017-2018 HUAWEI, Inc.
592e7cd0	4	* https://www.huawei.com/
c5aa903a	5	* Copyright (C) 2021, Alibaba Cloud
81781b02 GX	6	*/
	7	#include "internal.h"
	8	#include <linux/prefetch.h>
5375e7c8	9	#include <linux/sched/mm.h>
06252e9c	10	#include <linux/dax.h>
13f06f48 CY	11	#include <trace/events/erofs.h>
13f06f48 CY	12
fdf80a47 GX	13	void erofs_unmap_metabuf(struct erofs_buf *buf)
	14	{
	15	if (buf->kmap_type == EROFS_KMAP)
927e5010	16	kunmap_local(buf->base);
fdf80a47 GX	17	buf->base = NULL;
	18	buf->kmap_type = EROFS_NO_KMAP;
	19	}
	20
	21	void erofs_put_metabuf(struct erofs_buf *buf)
	22	{
	23	if (!buf->page)
	24	return;
	25	erofs_unmap_metabuf(buf);
	26	put_page(buf->page);
	27	buf->page = NULL;
	28	}
	29
fe5de585 GX	30	void erofs_bread(struct erofs_buf buf, struct inode *inode,
fe5de585 GX	31	erofs_blk_t blkaddr, enum erofs_kmap_type type)
fdf80a47	32	{
fe5de585	33	struct address_space *const mapping = inode->i_mapping;
fdf80a47 GX	34	erofs_off_t offset = blknr_to_addr(blkaddr);
	35	pgoff_t index = offset >> PAGE_SHIFT;
	36	struct page *page = buf->page;
5375e7c8 JX	37	struct folio *folio;
5375e7c8 JX	38	unsigned int nofs_flag;
fdf80a47 GX	39
	40	if (!page \|\| page->index != index) {
	41	erofs_put_metabuf(buf);
5375e7c8 JX	42
	43	nofs_flag = memalloc_nofs_save();
	44	folio = read_cache_folio(mapping, index, NULL, NULL);
	45	memalloc_nofs_restore(nofs_flag);
	46	if (IS_ERR(folio))
	47	return folio;
	48
fdf80a47	49	/* should already be PageUptodate, no need to lock page */
5375e7c8	50	page = folio_file_page(folio, index);
fdf80a47 GX	51	buf->page = page;
	52	}
	53	if (buf->kmap_type == EROFS_NO_KMAP) {
	54	if (type == EROFS_KMAP)
927e5010	55	buf->base = kmap_local_page(page);
fdf80a47 GX	56	buf->kmap_type = type;
	57	} else if (buf->kmap_type != type) {
	58	DBG_BUGON(1);
	59	return ERR_PTR(-EFAULT);
	60	}
	61	if (type == EROFS_NO_KMAP)
	62	return NULL;
	63	return buf->base + (offset & ~PAGE_MASK);
	64	}
	65
fe5de585 GX	66	void erofs_read_metabuf(struct erofs_buf buf, struct super_block *sb,
	67	erofs_blk_t blkaddr, enum erofs_kmap_type type)
	68	{
5375e7c8 JX	69	if (erofs_is_fscache_mode(sb))
	70	return erofs_bread(buf, EROFS_SB(sb)->s_fscache->inode,
	71	blkaddr, type);
	72
fe5de585 GX	73	return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type);
	74	}
	75
81781b02	76	static int erofs_map_blocks_flatmode(struct inode *inode,
8b58f9f0	77	struct erofs_map_blocks *map)
81781b02 GX	78	{
	79	erofs_blk_t nblocks, lastblk;
	80	u64 offset = map->m_la;
a5876e24	81	struct erofs_inode *vi = EROFS_I(inode);
8a765682	82	bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
81781b02	83
fdf80a47	84	nblocks = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
8a765682	85	lastblk = nblocks - tailendpacking;
81781b02	86
81781b02 GX	87	/* there is no hole in flatmode */
81781b02 GX	88	map->m_flags = EROFS_MAP_MAPPED;
81781b02 GX	89	if (offset < blknr_to_addr(lastblk)) {
	90	map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
	91	map->m_plen = blknr_to_addr(lastblk) - offset;
8a765682	92	} else if (tailendpacking) {
b780d3fc GX	93	map->m_pa = erofs_iloc(inode) + vi->inode_isize +
b780d3fc GX	94	vi->xattr_isize + erofs_blkoff(offset);
81781b02 GX	95	map->m_plen = inode->i_size - offset;
81781b02 GX	96
469407a3 GX	97	/* inline data should be located in the same meta block */
469407a3 GX	98	if (erofs_blkoff(map->m_pa) + map->m_plen > EROFS_BLKSIZ) {
4f761fa2 GX	99	erofs_err(inode->i_sb,
	100	"inline data cross block boundary @ nid %llu",
	101	vi->nid);
9141b60c	102	DBG_BUGON(1);
469407a3	103	return -EFSCORRUPTED;
9141b60c	104	}
81781b02 GX	105	map->m_flags \|= EROFS_MAP_META;
81781b02 GX	106	} else {
4f761fa2 GX	107	erofs_err(inode->i_sb,
	108	"internal error @ nid: %llu (size %llu), m_la 0x%llx",
	109	vi->nid, inode->i_size, map->m_la);
9141b60c	110	DBG_BUGON(1);
469407a3	111	return -EIO;
81781b02	112	}
469407a3	113	return 0;
81781b02 GX	114	}
81781b02 GX	115
8b58f9f0	116	int erofs_map_blocks(struct inode inode, struct erofs_map_blocks map)
c5aa903a GX	117	{
	118	struct super_block *sb = inode->i_sb;
	119	struct erofs_inode *vi = EROFS_I(inode);
	120	struct erofs_inode_chunk_index *idx;
fdf80a47	121	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
c5aa903a GX	122	u64 chunknr;
	123	unsigned int unit;
	124	erofs_off_t pos;
fdf80a47	125	void *kaddr;
c5aa903a GX	126	int err = 0;
c5aa903a GX	127
8b58f9f0	128	trace_erofs_map_blocks_enter(inode, map, 0);
dfeab2e9	129	map->m_deviceid = 0;
c5aa903a GX	130	if (map->m_la >= inode->i_size) {
	131	/* leave out-of-bound access unmapped */
	132	map->m_flags = 0;
	133	map->m_plen = 0;
	134	goto out;
	135	}
	136
469407a3	137	if (vi->datalayout != EROFS_INODE_CHUNK_BASED) {
8b58f9f0	138	err = erofs_map_blocks_flatmode(inode, map);
469407a3 GX	139	goto out;
469407a3 GX	140	}
c5aa903a GX	141
	142	if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
	143	unit = sizeof(idx); / chunk index */
	144	else
	145	unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */
	146
	147	chunknr = map->m_la >> vi->chunkbits;
b780d3fc	148	pos = ALIGN(erofs_iloc(inode) + vi->inode_isize +
c5aa903a GX	149	vi->xattr_isize, unit) + unit * chunknr;
c5aa903a GX	150
fdf80a47 GX	151	kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP);
	152	if (IS_ERR(kaddr)) {
	153	err = PTR_ERR(kaddr);
469407a3 GX	154	goto out;
469407a3 GX	155	}
c5aa903a GX	156	map->m_la = chunknr << vi->chunkbits;
	157	map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits,
	158	roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));
	159
	160	/* handle block map */
	161	if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
fdf80a47	162	__le32 *blkaddr = kaddr + erofs_blkoff(pos);
c5aa903a GX	163
	164	if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
	165	map->m_flags = 0;
	166	} else {
	167	map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr));
	168	map->m_flags = EROFS_MAP_MAPPED;
	169	}
	170	goto out_unlock;
	171	}
	172	/* parse chunk indexes */
fdf80a47	173	idx = kaddr + erofs_blkoff(pos);
c5aa903a GX	174	switch (le32_to_cpu(idx->blkaddr)) {
	175	case EROFS_NULL_ADDR:
	176	map->m_flags = 0;
	177	break;
	178	default:
dfeab2e9 GX	179	map->m_deviceid = le16_to_cpu(idx->device_id) &
dfeab2e9 GX	180	EROFS_SB(sb)->device_id_mask;
c5aa903a GX	181	map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr));
	182	map->m_flags = EROFS_MAP_MAPPED;
	183	break;
	184	}
	185	out_unlock:
fdf80a47	186	erofs_put_metabuf(&buf);
c5aa903a	187	out:
469407a3 GX	188	if (!err)
469407a3 GX	189	map->m_llen = map->m_plen;
8b58f9f0	190	trace_erofs_map_blocks_exit(inode, map, 0, err);
c5aa903a GX	191	return err;
	192	}
	193
dfeab2e9 GX	194	int erofs_map_dev(struct super_block sb, struct erofs_map_dev map)
	195	{
	196	struct erofs_dev_context *devs = EROFS_SB(sb)->devs;
	197	struct erofs_device_info *dif;
	198	int id;
	199
	200	/* primary device by default */
	201	map->m_bdev = sb->s_bdev;
	202	map->m_daxdev = EROFS_SB(sb)->dax_dev;
de205114	203	map->m_dax_part_off = EROFS_SB(sb)->dax_part_off;
955b478e	204	map->m_fscache = EROFS_SB(sb)->s_fscache;
dfeab2e9 GX	205
	206	if (map->m_deviceid) {
	207	down_read(&devs->rwsem);
	208	dif = idr_find(&devs->tree, map->m_deviceid - 1);
	209	if (!dif) {
	210	up_read(&devs->rwsem);
	211	return -ENODEV;
	212	}
	213	map->m_bdev = dif->bdev;
	214	map->m_daxdev = dif->dax_dev;
de205114	215	map->m_dax_part_off = dif->dax_part_off;
955b478e	216	map->m_fscache = dif->fscache;
dfeab2e9 GX	217	up_read(&devs->rwsem);
	218	} else if (devs->extra_devices) {
	219	down_read(&devs->rwsem);
	220	idr_for_each_entry(&devs->tree, dif, id) {
	221	erofs_off_t startoff, length;
	222
	223	if (!dif->mapped_blkaddr)
	224	continue;
	225	startoff = blknr_to_addr(dif->mapped_blkaddr);
	226	length = blknr_to_addr(dif->blocks);
	227
	228	if (map->m_pa >= startoff &&
	229	map->m_pa < startoff + length) {
	230	map->m_pa -= startoff;
	231	map->m_bdev = dif->bdev;
	232	map->m_daxdev = dif->dax_dev;
de205114	233	map->m_dax_part_off = dif->dax_part_off;
955b478e	234	map->m_fscache = dif->fscache;
dfeab2e9 GX	235	break;
	236	}
	237	}
	238	up_read(&devs->rwsem);
	239	}
	240	return 0;
	241	}
	242
a08e67a0 HJ	243	static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
	244	unsigned int flags, struct iomap iomap, struct iomap srcmap)
	245	{
	246	int ret;
	247	struct erofs_map_blocks map;
dfeab2e9	248	struct erofs_map_dev mdev;
a08e67a0 HJ	249
	250	map.m_la = offset;
	251	map.m_llen = length;
	252
8b58f9f0	253	ret = erofs_map_blocks(inode, &map);
a08e67a0 HJ	254	if (ret < 0)
	255	return ret;
	256
dfeab2e9 GX	257	mdev = (struct erofs_map_dev) {
	258	.m_deviceid = map.m_deviceid,
	259	.m_pa = map.m_pa,
	260	};
	261	ret = erofs_map_dev(inode->i_sb, &mdev);
	262	if (ret)
	263	return ret;
	264
a08e67a0	265	iomap->offset = map.m_la;
e33f42b2	266	if (flags & IOMAP_DAX)
de205114	267	iomap->dax_dev = mdev.m_daxdev;
e33f42b2	268	else
de205114	269	iomap->bdev = mdev.m_bdev;
a08e67a0 HJ	270	iomap->length = map.m_llen;
a08e67a0 HJ	271	iomap->flags = 0;
771c994e	272	iomap->private = NULL;
a08e67a0 HJ	273
	274	if (!(map.m_flags & EROFS_MAP_MAPPED)) {
	275	iomap->type = IOMAP_HOLE;
	276	iomap->addr = IOMAP_NULL_ADDR;
	277	if (!iomap->length)
	278	iomap->length = length;
	279	return 0;
	280	}
	281
a08e67a0	282	if (map.m_flags & EROFS_MAP_META) {
fdf80a47 GX	283	void *ptr;
fdf80a47 GX	284	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
771c994e GX	285
771c994e GX	286	iomap->type = IOMAP_INLINE;
fdf80a47 GX	287	ptr = erofs_read_metabuf(&buf, inode->i_sb,
	288	erofs_blknr(mdev.m_pa), EROFS_KMAP);
	289	if (IS_ERR(ptr))
	290	return PTR_ERR(ptr);
	291	iomap->inline_data = ptr + erofs_blkoff(mdev.m_pa);
	292	iomap->private = buf.base;
771c994e GX	293	} else {
771c994e GX	294	iomap->type = IOMAP_MAPPED;
dfeab2e9	295	iomap->addr = mdev.m_pa;
e33f42b2 GX	296	if (flags & IOMAP_DAX)
e33f42b2 GX	297	iomap->addr += mdev.m_dax_part_off;
a08e67a0	298	}
a08e67a0 HJ	299	return 0;
	300	}
	301
771c994e GX	302	static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
	303	ssize_t written, unsigned int flags, struct iomap *iomap)
	304	{
fdf80a47 GX	305	void *ptr = iomap->private;
	306
	307	if (ptr) {
	308	struct erofs_buf buf = {
	309	.page = kmap_to_page(ptr),
	310	.base = ptr,
	311	.kmap_type = EROFS_KMAP,
	312	};
771c994e	313
771c994e	314	DBG_BUGON(iomap->type != IOMAP_INLINE);
fdf80a47	315	erofs_put_metabuf(&buf);
771c994e GX	316	} else {
	317	DBG_BUGON(iomap->type == IOMAP_INLINE);
	318	}
	319	return written;
	320	}
	321
a08e67a0 HJ	322	static const struct iomap_ops erofs_iomap_ops = {
a08e67a0 HJ	323	.iomap_begin = erofs_iomap_begin,
771c994e	324	.iomap_end = erofs_iomap_end,
a08e67a0 HJ	325	};
a08e67a0 HJ	326
eadcd6b5 GX	327	int erofs_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
	328	u64 start, u64 len)
	329	{
	330	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
	331	#ifdef CONFIG_EROFS_FS_ZIP
	332	return iomap_fiemap(inode, fieinfo, start, len,
	333	&z_erofs_iomap_report_ops);
	334	#else
	335	return -EOPNOTSUPP;
	336	#endif
	337	}
	338	return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops);
	339	}
	340
771c994e GX	341	/*
	342	* since we dont have write or truncate flows, so no inode
	343	* locking needs to be held at the moment.
	344	*/
7479c505	345	static int erofs_read_folio(struct file file, struct folio folio)
771c994e	346	{
7479c505	347	return iomap_read_folio(folio, &erofs_iomap_ops);
771c994e GX	348	}
	349
	350	static void erofs_readahead(struct readahead_control *rac)
	351	{
	352	return iomap_readahead(rac, &erofs_iomap_ops);
	353	}
	354
	355	static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
	356	{
	357	return iomap_bmap(mapping, block, &erofs_iomap_ops);
	358	}
	359
de8a801a	360	static ssize_t erofs_file_read_iter(struct kiocb iocb, struct iov_iter to)
a08e67a0 HJ	361	{
a08e67a0 HJ	362	struct inode *inode = file_inode(iocb->ki_filp);
a08e67a0	363
a08e67a0 HJ	364	/* no need taking (shared) inode lock since it's a ro filesystem */
	365	if (!iov_iter_count(to))
	366	return 0;
	367
06252e9c	368	#ifdef CONFIG_FS_DAX
de8a801a	369	if (IS_DAX(inode))
06252e9c GX	370	return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
06252e9c GX	371	#endif
a08e67a0	372	if (iocb->ki_flags & IOCB_DIRECT) {
de8a801a GX	373	struct block_device *bdev = inode->i_sb->s_bdev;
	374	unsigned int blksize_mask;
	375
	376	if (bdev)
	377	blksize_mask = bdev_logical_block_size(bdev) - 1;
	378	else
3993f4f4	379	blksize_mask = i_blocksize(inode) - 1;
de8a801a GX	380
	381	if ((iocb->ki_pos \| iov_iter_count(to) \|
	382	iov_iter_alignment(to)) & blksize_mask)
	383	return -EINVAL;
a08e67a0	384
de8a801a GX	385	return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
de8a801a GX	386	NULL, 0, NULL, 0);
a08e67a0 HJ	387	}
	388	return filemap_read(iocb, to, 0);
	389	}
	390
81781b02 GX	391	/* for uncompressed (aligned) files and raw access for other files */
81781b02 GX	392	const struct address_space_operations erofs_raw_access_aops = {
7479c505	393	.read_folio = erofs_read_folio,
771c994e	394	.readahead = erofs_readahead,
9da681e0	395	.bmap = erofs_bmap,
a08e67a0	396	.direct_IO = noop_direct_IO,
ce529cc2 JX	397	.release_folio = iomap_release_folio,
ce529cc2 JX	398	.invalidate_folio = iomap_invalidate_folio,
a08e67a0 HJ	399	};
a08e67a0 HJ	400
06252e9c GX	401	#ifdef CONFIG_FS_DAX
	402	static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf,
	403	enum page_entry_size pe_size)
	404	{
	405	return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops);
	406	}
	407
	408	static vm_fault_t erofs_dax_fault(struct vm_fault *vmf)
	409	{
	410	return erofs_dax_huge_fault(vmf, PE_SIZE_PTE);
	411	}
	412
	413	static const struct vm_operations_struct erofs_dax_vm_ops = {
	414	.fault = erofs_dax_fault,
	415	.huge_fault = erofs_dax_huge_fault,
	416	};
	417
	418	static int erofs_file_mmap(struct file file, struct vm_area_struct vma)
	419	{
	420	if (!IS_DAX(file_inode(file)))
	421	return generic_file_readonly_mmap(file, vma);
	422
	423	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
	424	return -EINVAL;
	425
	426	vma->vm_ops = &erofs_dax_vm_ops;
1c71222e	427	vm_flags_set(vma, VM_HUGEPAGE);
06252e9c GX	428	return 0;
	429	}
	430	#else
	431	#define erofs_file_mmap generic_file_readonly_mmap
	432	#endif
	433
a08e67a0 HJ	434	const struct file_operations erofs_file_fops = {
	435	.llseek = generic_file_llseek,
	436	.read_iter = erofs_file_read_iter,
06252e9c	437	.mmap = erofs_file_mmap,
a08e67a0	438	.splice_read = generic_file_splice_read,
81781b02	439	};