xref: /linux/fs/iomap/fiemap.c (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
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 
11 struct fiemap_ctx {
12 	struct fiemap_extent_info *fi;
13 	struct iomap prev;
14 };
15 
16 static 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 
46 static loff_t
47 iomap_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 
68 int 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 }
105 EXPORT_SYMBOL_GPL(iomap_fiemap);
106 
107 static loff_t
108 iomap_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 (!) */
121 sector_t
122 iomap_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 }
140 EXPORT_SYMBOL_GPL(iomap_bmap);
141