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
10 struct fiemap_ctx {
11 struct fiemap_extent_info *fi;
12 struct iomap prev;
13 };
14
iomap_to_fiemap(struct fiemap_extent_info * fi,struct iomap * iomap,u32 flags)15 static int iomap_to_fiemap(struct fiemap_extent_info *fi,
16 struct iomap *iomap, u32 flags)
17 {
18 switch (iomap->type) {
19 case IOMAP_HOLE:
20 /* skip holes */
21 return 0;
22 case IOMAP_DELALLOC:
23 flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
24 break;
25 case IOMAP_MAPPED:
26 break;
27 case IOMAP_UNWRITTEN:
28 flags |= FIEMAP_EXTENT_UNWRITTEN;
29 break;
30 case IOMAP_INLINE:
31 flags |= FIEMAP_EXTENT_DATA_INLINE;
32 break;
33 }
34
35 if (iomap->flags & IOMAP_F_MERGED)
36 flags |= FIEMAP_EXTENT_MERGED;
37 if (iomap->flags & IOMAP_F_SHARED)
38 flags |= FIEMAP_EXTENT_SHARED;
39
40 return fiemap_fill_next_extent(fi, iomap->offset,
41 iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
42 iomap->length, flags);
43 }
44
45 static loff_t
iomap_fiemap_actor(struct inode * inode,loff_t pos,loff_t length,void * data,struct iomap * iomap)46 iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
47 struct iomap *iomap)
48 {
49 struct fiemap_ctx *ctx = data;
50 loff_t ret = length;
51
52 if (iomap->type == IOMAP_HOLE)
53 return length;
54
55 ret = iomap_to_fiemap(ctx->fi, &ctx->prev, 0);
56 ctx->prev = *iomap;
57 switch (ret) {
58 case 0: /* success */
59 return length;
60 case 1: /* extent array full */
61 return 0;
62 default:
63 return ret;
64 }
65 }
66
iomap_fiemap(struct inode * inode,struct fiemap_extent_info * fi,loff_t start,loff_t len,const struct iomap_ops * ops)67 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
68 loff_t start, loff_t len, const struct iomap_ops *ops)
69 {
70 struct fiemap_ctx ctx;
71 loff_t ret;
72
73 memset(&ctx, 0, sizeof(ctx));
74 ctx.fi = fi;
75 ctx.prev.type = IOMAP_HOLE;
76
77 ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC);
78 if (ret)
79 return ret;
80
81 if (fi->fi_flags & FIEMAP_FLAG_SYNC) {
82 ret = filemap_write_and_wait(inode->i_mapping);
83 if (ret)
84 return ret;
85 }
86
87 while (len > 0) {
88 ret = iomap_apply(inode, start, len, IOMAP_REPORT, ops, &ctx,
89 iomap_fiemap_actor);
90 /* inode with no (attribute) mapping will give ENOENT */
91 if (ret == -ENOENT)
92 break;
93 if (ret < 0)
94 return ret;
95 if (ret == 0)
96 break;
97
98 start += ret;
99 len -= ret;
100 }
101
102 if (ctx.prev.type != IOMAP_HOLE) {
103 ret = iomap_to_fiemap(fi, &ctx.prev, FIEMAP_EXTENT_LAST);
104 if (ret < 0)
105 return ret;
106 }
107
108 return 0;
109 }
110 EXPORT_SYMBOL_GPL(iomap_fiemap);
111
112 static loff_t
iomap_bmap_actor(struct inode * inode,loff_t pos,loff_t length,void * data,struct iomap * iomap)113 iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
114 void *data, struct iomap *iomap)
115 {
116 sector_t *bno = data, addr;
117
118 if (iomap->type == IOMAP_MAPPED) {
119 addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
120 if (addr > INT_MAX)
121 WARN(1, "would truncate bmap result\n");
122 else
123 *bno = addr;
124 }
125 return 0;
126 }
127
128 /* legacy ->bmap interface. 0 is the error return (!) */
129 sector_t
iomap_bmap(struct address_space * mapping,sector_t bno,const struct iomap_ops * ops)130 iomap_bmap(struct address_space *mapping, sector_t bno,
131 const struct iomap_ops *ops)
132 {
133 struct inode *inode = mapping->host;
134 loff_t pos = bno << inode->i_blkbits;
135 unsigned blocksize = i_blocksize(inode);
136
137 if (filemap_write_and_wait(mapping))
138 return 0;
139
140 bno = 0;
141 iomap_apply(inode, pos, blocksize, 0, ops, &bno, iomap_bmap_actor);
142 return bno;
143 }
144 EXPORT_SYMBOL_GPL(iomap_bmap);
145