1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2016-2021 Christoph Hellwig.
4 */
5#include <linux/module.h>
6#include <linux/compiler.h>
7#include <linux/fs.h>
8#include <linux/iomap.h>
9#include <linux/fiemap.h>
10#include <linux/pagemap.h>
11
12static int iomap_to_fiemap(struct fiemap_extent_info *fi,
13		const struct iomap *iomap, u32 flags)
14{
15	switch (iomap->type) {
16	case IOMAP_HOLE:
17		/* skip holes */
18		return 0;
19	case IOMAP_DELALLOC:
20		flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
21		break;
22	case IOMAP_MAPPED:
23		break;
24	case IOMAP_UNWRITTEN:
25		flags |= FIEMAP_EXTENT_UNWRITTEN;
26		break;
27	case IOMAP_INLINE:
28		flags |= FIEMAP_EXTENT_DATA_INLINE;
29		break;
30	}
31
32	if (iomap->flags & IOMAP_F_MERGED)
33		flags |= FIEMAP_EXTENT_MERGED;
34	if (iomap->flags & IOMAP_F_SHARED)
35		flags |= FIEMAP_EXTENT_SHARED;
36
37	return fiemap_fill_next_extent(fi, iomap->offset,
38			iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
39			iomap->length, flags);
40}
41
42static loff_t iomap_fiemap_iter(const struct iomap_iter *iter,
43		struct fiemap_extent_info *fi, struct iomap *prev)
44{
45	int ret;
46
47	if (iter->iomap.type == IOMAP_HOLE)
48		return iomap_length(iter);
49
50	ret = iomap_to_fiemap(fi, prev, 0);
51	*prev = iter->iomap;
52	switch (ret) {
53	case 0:		/* success */
54		return iomap_length(iter);
55	case 1:		/* extent array full */
56		return 0;
57	default:	/* error */
58		return ret;
59	}
60}
61
62int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
63		u64 start, u64 len, const struct iomap_ops *ops)
64{
65	struct iomap_iter iter = {
66		.inode		= inode,
67		.pos		= start,
68		.len		= len,
69		.flags		= IOMAP_REPORT,
70	};
71	struct iomap prev = {
72		.type		= IOMAP_HOLE,
73	};
74	int ret;
75
76	ret = fiemap_prep(inode, fi, start, &iter.len, 0);
77	if (ret)
78		return ret;
79
80	while ((ret = iomap_iter(&iter, ops)) > 0)
81		iter.processed = iomap_fiemap_iter(&iter, fi, &prev);
82
83	if (prev.type != IOMAP_HOLE) {
84		ret = iomap_to_fiemap(fi, &prev, FIEMAP_EXTENT_LAST);
85		if (ret < 0)
86			return ret;
87	}
88
89	/* inode with no (attribute) mapping will give ENOENT */
90	if (ret < 0 && ret != -ENOENT)
91		return ret;
92	return 0;
93}
94EXPORT_SYMBOL_GPL(iomap_fiemap);
95
96/* legacy ->bmap interface.  0 is the error return (!) */
97sector_t
98iomap_bmap(struct address_space *mapping, sector_t bno,
99		const struct iomap_ops *ops)
100{
101	struct iomap_iter iter = {
102		.inode	= mapping->host,
103		.pos	= (loff_t)bno << mapping->host->i_blkbits,
104		.len	= i_blocksize(mapping->host),
105		.flags	= IOMAP_REPORT,
106	};
107	const unsigned int blkshift = mapping->host->i_blkbits - SECTOR_SHIFT;
108	int ret;
109
110	if (filemap_write_and_wait(mapping))
111		return 0;
112
113	bno = 0;
114	while ((ret = iomap_iter(&iter, ops)) > 0) {
115		if (iter.iomap.type == IOMAP_MAPPED)
116			bno = iomap_sector(&iter.iomap, iter.pos) >> blkshift;
117		/* leave iter.processed unset to abort loop */
118	}
119	if (ret)
120		return 0;
121
122	return bno;
123}
124EXPORT_SYMBOL_GPL(iomap_bmap);
125