xref: /linux/fs/iomap/fiemap.c (revision 8e6415460ff16f5a9673a021547e0a34358ddfe9)
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 
iomap_to_fiemap(struct fiemap_extent_info * fi,const struct iomap * iomap,u32 flags)12 static 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 
iomap_fiemap_iter(struct iomap_iter * iter,struct fiemap_extent_info * fi,struct iomap * prev)42 static int iomap_fiemap_iter(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 		goto advance;
49 
50 	ret = iomap_to_fiemap(fi, prev, 0);
51 	*prev = iter->iomap;
52 	if (ret < 0)
53 		return ret;
54 	if (ret == 1)	/* extent array full */
55 		return 0;
56 
57 advance:
58 	return iomap_iter_advance_full(iter);
59 }
60 
iomap_fiemap(struct inode * inode,struct fiemap_extent_info * fi,u64 start,u64 len,const struct iomap_ops * ops)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.status = 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
iomap_bmap(struct address_space * mapping,sector_t bno,const struct iomap_ops * ops)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.status unset to abort loop */
117 	}
118 	if (ret)
119 		return 0;
120 
121 	return bno;
122 }
123 EXPORT_SYMBOL_GPL(iomap_bmap);
124