xref: /kernel/linux/linux-5.10/fs/iomap/fiemap.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2016-2018 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
11struct fiemap_ctx {
12	struct fiemap_extent_info *fi;
13	struct iomap prev;
14};
15
16static int iomap_to_fiemap(struct fiemap_extent_info *fi,
17		struct iomap *iomap, u32 flags)
18{
19	switch (iomap->type) {
20	case IOMAP_HOLE:
21		/* skip holes */
22		return 0;
23	case IOMAP_DELALLOC:
24		flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
25		break;
26	case IOMAP_MAPPED:
27		break;
28	case IOMAP_UNWRITTEN:
29		flags |= FIEMAP_EXTENT_UNWRITTEN;
30		break;
31	case IOMAP_INLINE:
32		flags |= FIEMAP_EXTENT_DATA_INLINE;
33		break;
34	}
35
36	if (iomap->flags & IOMAP_F_MERGED)
37		flags |= FIEMAP_EXTENT_MERGED;
38	if (iomap->flags & IOMAP_F_SHARED)
39		flags |= FIEMAP_EXTENT_SHARED;
40
41	return fiemap_fill_next_extent(fi, iomap->offset,
42			iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
43			iomap->length, flags);
44}
45
46static loff_t
47iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
48		struct iomap *iomap, struct iomap *srcmap)
49{
50	struct fiemap_ctx *ctx = data;
51	loff_t ret = length;
52
53	if (iomap->type == IOMAP_HOLE)
54		return length;
55
56	ret = iomap_to_fiemap(ctx->fi, &ctx->prev, 0);
57	ctx->prev = *iomap;
58	switch (ret) {
59	case 0:		/* success */
60		return length;
61	case 1:		/* extent array full */
62		return 0;
63	default:
64		return ret;
65	}
66}
67
68int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
69		u64 start, u64 len, const struct iomap_ops *ops)
70{
71	struct fiemap_ctx ctx;
72	loff_t ret;
73
74	memset(&ctx, 0, sizeof(ctx));
75	ctx.fi = fi;
76	ctx.prev.type = IOMAP_HOLE;
77
78	ret = fiemap_prep(inode, fi, start, &len, 0);
79	if (ret)
80		return ret;
81
82	while (len > 0) {
83		ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
84				iomap_fiemap_actor);
85		/* inode with no (attribute) mapping will give ENOENT */
86		if (ret == -ENOENT)
87			break;
88		if (ret < 0)
89			return ret;
90		if (ret == 0)
91			break;
92
93		start += ret;
94		len -= ret;
95	}
96
97	if (ctx.prev.type != IOMAP_HOLE) {
98		ret = iomap_to_fiemap(fi, &ctx.prev, FIEMAP_EXTENT_LAST);
99		if (ret < 0)
100			return ret;
101	}
102
103	return 0;
104}
105EXPORT_SYMBOL_GPL(iomap_fiemap);
106
107static loff_t
108iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
109		void *data, struct iomap *iomap, struct iomap *srcmap)
110{
111	sector_t *bno = data, addr;
112
113	if (iomap->type == IOMAP_MAPPED) {
114		addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
115		*bno = addr;
116	}
117	return 0;
118}
119
120/* legacy ->bmap interface.  0 is the error return (!) */
121sector_t
122iomap_bmap(struct address_space *mapping, sector_t bno,
123		const struct iomap_ops *ops)
124{
125	struct inode *inode = mapping->host;
126	loff_t pos = bno << inode->i_blkbits;
127	unsigned blocksize = i_blocksize(inode);
128	int ret;
129
130	if (filemap_write_and_wait(mapping))
131		return 0;
132
133	bno = 0;
134	ret = iomap_apply(inode, pos, blocksize, 0, ops, &bno,
135			  iomap_bmap_actor);
136	if (ret)
137		return 0;
138	return bno;
139}
140EXPORT_SYMBOL_GPL(iomap_bmap);
141