aboutsummaryrefslogtreecommitdiff
path: root/fs/iomap/fiemap.c
blob: bccf305ea9ce26d1f34ac9f10157af448c1f3174 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2016-2018 Christoph Hellwig.
 */
#include <linux/module.h>
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/iomap.h>

struct fiemap_ctx {
	struct fiemap_extent_info *fi;
	struct iomap prev;
};

static int iomap_to_fiemap(struct fiemap_extent_info *fi,
		struct iomap *iomap, u32 flags)
{
	switch (iomap->type) {
	case IOMAP_HOLE:
		/* skip holes */
		return 0;
	case IOMAP_DELALLOC:
		flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
		break;
	case IOMAP_MAPPED:
		break;
	case IOMAP_UNWRITTEN:
		flags |= FIEMAP_EXTENT_UNWRITTEN;
		break;
	case IOMAP_INLINE:
		flags |= FIEMAP_EXTENT_DATA_INLINE;
		break;
	}

	if (iomap->flags & IOMAP_F_MERGED)
		flags |= FIEMAP_EXTENT_MERGED;
	if (iomap->flags & IOMAP_F_SHARED)
		flags |= FIEMAP_EXTENT_SHARED;

	return fiemap_fill_next_extent(fi, iomap->offset,
			iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
			iomap->length, flags);
}

static loff_t
iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
		struct iomap *iomap, struct iomap *srcmap)
{
	struct fiemap_ctx *ctx = data;
	loff_t ret = length;

	if (iomap->type == IOMAP_HOLE)
		return length;

	ret = iomap_to_fiemap(ctx->fi, &ctx->prev, 0);
	ctx->prev = *iomap;
	switch (ret) {
	case 0:		/* success */
		return length;
	case 1:		/* extent array full */
		return 0;
	default:
		return ret;
	}
}

int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
		loff_t start, loff_t len, const struct iomap_ops *ops)
{
	struct fiemap_ctx ctx;
	loff_t ret;

	memset(&ctx, 0, sizeof(ctx));
	ctx.fi = fi;
	ctx.prev.type = IOMAP_HOLE;

	ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC);
	if (ret)
		return ret;

	if (fi->fi_flags & FIEMAP_FLAG_SYNC) {
		ret = filemap_write_and_wait(inode->i_mapping);
		if (ret)
			return ret;
	}

	while (len > 0) {
		ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
				iomap_fiemap_actor);
		/* inode with no (attribute) mapping will give ENOENT */
		if (ret == -ENOENT)
			break;
		if (ret < 0)
			return ret;
		if (ret == 0)
			break;

		start += ret;
		len -= ret;
	}

	if (ctx.prev.type != IOMAP_HOLE) {
		ret = iomap_to_fiemap(fi, &ctx.prev, FIEMAP_EXTENT_LAST);
		if (ret < 0)
			return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(iomap_fiemap);

static loff_t
iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
		void *data, struct iomap *iomap, struct iomap *srcmap)
{
	sector_t *bno = data, addr;

	if (iomap->type == IOMAP_MAPPED) {
		addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
		if (addr > INT_MAX)
			WARN(1, "would truncate bmap result\n");
		else
			*bno = addr;
	}
	return 0;
}

/* legacy ->bmap interface.  0 is the error return (!) */
sector_t
iomap_bmap(struct address_space *mapping, sector_t bno,
		const struct iomap_ops *ops)
{
	struct inode *inode = mapping->host;
	loff_t pos = bno << inode->i_blkbits;
	unsigned blocksize = i_blocksize(inode);
	int ret;

	if (filemap_write_and_wait(mapping))
		return 0;

	bno = 0;
	ret = iomap_apply(inode, pos, blocksize, 0, ops, &bno,
			  iomap_bmap_actor);
	if (ret)
		return 0;
	return bno;
}
EXPORT_SYMBOL_GPL(iomap_bmap);