xref: /linux/fs/iomap/fiemap.c (revision 5bbfea1eacdf584d0d159e38c01ee190162706d9)
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 
11 static int iomap_to_fiemap(struct fiemap_extent_info *fi,
12 		const struct iomap *iomap, u32 flags)
13 {
14 	switch (iomap->type) {
15 	case IOMAP_HOLE:
16 		/* skip holes */
17 		return 0;
18 	case IOMAP_DELALLOC:
19 		flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
20 		break;
21 	case IOMAP_MAPPED:
22 		break;
23 	case IOMAP_UNWRITTEN:
24 		flags |= FIEMAP_EXTENT_UNWRITTEN;
25 		break;
26 	case IOMAP_INLINE:
27 		flags |= FIEMAP_EXTENT_DATA_INLINE;
28 		break;
29 	}
30 
31 	if (iomap->flags & IOMAP_F_MERGED)
32 		flags |= FIEMAP_EXTENT_MERGED;
33 	if (iomap->flags & IOMAP_F_SHARED)
34 		flags |= FIEMAP_EXTENT_SHARED;
35 
36 	return fiemap_fill_next_extent(fi, iomap->offset,
37 			iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
38 			iomap->length, flags);
39 }
40 
41 static loff_t iomap_fiemap_iter(const struct iomap_iter *iter,
42 		struct fiemap_extent_info *fi, struct iomap *prev)
43 {
44 	int ret;
45 
46 	if (iter->iomap.type == IOMAP_HOLE)
47 		return iomap_length(iter);
48 
49 	ret = iomap_to_fiemap(fi, prev, 0);
50 	*prev = iter->iomap;
51 	switch (ret) {
52 	case 0:		/* success */
53 		return iomap_length(iter);
54 	case 1:		/* extent array full */
55 		return 0;
56 	default:	/* error */
57 		return ret;
58 	}
59 }
60 
61 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
62 		u64 start, u64 len, const struct iomap_ops *ops)
63 {
64 	struct iomap_iter iter = {
65 		.inode		= inode,
66 		.pos		= start,
67 		.len		= len,
68 		.flags		= IOMAP_REPORT,
69 	};
70 	struct iomap prev = {
71 		.type		= IOMAP_HOLE,
72 	};
73 	int ret;
74 
75 	ret = fiemap_prep(inode, fi, start, &iter.len, 0);
76 	if (ret)
77 		return ret;
78 
79 	while ((ret = iomap_iter(&iter, ops)) > 0)
80 		iter.processed = iomap_fiemap_iter(&iter, fi, &prev);
81 
82 	if (prev.type != IOMAP_HOLE) {
83 		ret = iomap_to_fiemap(fi, &prev, FIEMAP_EXTENT_LAST);
84 		if (ret < 0)
85 			return ret;
86 	}
87 
88 	/* inode with no (attribute) mapping will give ENOENT */
89 	if (ret < 0 && ret != -ENOENT)
90 		return ret;
91 	return 0;
92 }
93 EXPORT_SYMBOL_GPL(iomap_fiemap);
94 
95 /* legacy ->bmap interface.  0 is the error return (!) */
96 sector_t
97 iomap_bmap(struct address_space *mapping, sector_t bno,
98 		const struct iomap_ops *ops)
99 {
100 	struct iomap_iter iter = {
101 		.inode	= mapping->host,
102 		.pos	= (loff_t)bno << mapping->host->i_blkbits,
103 		.len	= i_blocksize(mapping->host),
104 		.flags	= IOMAP_REPORT,
105 	};
106 	const unsigned int blkshift = mapping->host->i_blkbits - SECTOR_SHIFT;
107 	int ret;
108 
109 	if (filemap_write_and_wait(mapping))
110 		return 0;
111 
112 	bno = 0;
113 	while ((ret = iomap_iter(&iter, ops)) > 0) {
114 		if (iter.iomap.type == IOMAP_MAPPED)
115 			bno = iomap_sector(&iter.iomap, iter.pos) >> blkshift;
116 		/* leave iter.processed unset to abort loop */
117 	}
118 	if (ret)
119 		return 0;
120 
121 	return bno;
122 }
123 EXPORT_SYMBOL_GPL(iomap_bmap);
124