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6#include <linux/module.h>
7#include <linux/compiler.h>
8#include <linux/fs.h>
9#include <linux/iomap.h>
10#include <linux/swap.h>
11
12
13
14struct iomap_swapfile_info {
15 struct iomap iomap;
16 struct swap_info_struct *sis;
17 uint64_t lowest_ppage;
18 uint64_t highest_ppage;
19 unsigned long nr_pages;
20 int nr_extents;
21};
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27
28
29static int iomap_swapfile_add_extent(struct iomap_swapfile_info *isi)
30{
31 struct iomap *iomap = &isi->iomap;
32 unsigned long nr_pages;
33 uint64_t first_ppage;
34 uint64_t first_ppage_reported;
35 uint64_t next_ppage;
36 int error;
37
38
39
40
41
42 first_ppage = ALIGN(iomap->addr, PAGE_SIZE) >> PAGE_SHIFT;
43 next_ppage = ALIGN_DOWN(iomap->addr + iomap->length, PAGE_SIZE) >>
44 PAGE_SHIFT;
45
46
47 if (first_ppage >= next_ppage)
48 return 0;
49 nr_pages = next_ppage - first_ppage;
50
51
52
53
54
55
56 first_ppage_reported = first_ppage;
57 if (iomap->offset == 0)
58 first_ppage_reported++;
59 if (isi->lowest_ppage > first_ppage_reported)
60 isi->lowest_ppage = first_ppage_reported;
61 if (isi->highest_ppage < (next_ppage - 1))
62 isi->highest_ppage = next_ppage - 1;
63
64
65 error = add_swap_extent(isi->sis, isi->nr_pages, nr_pages, first_ppage);
66 if (error < 0)
67 return error;
68 isi->nr_extents += error;
69 isi->nr_pages += nr_pages;
70 return 0;
71}
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75
76
77
78static loff_t iomap_swapfile_activate_actor(struct inode *inode, loff_t pos,
79 loff_t count, void *data, struct iomap *iomap,
80 struct iomap *srcmap)
81{
82 struct iomap_swapfile_info *isi = data;
83 int error;
84
85 switch (iomap->type) {
86 case IOMAP_MAPPED:
87 case IOMAP_UNWRITTEN:
88
89 break;
90 case IOMAP_INLINE:
91
92 pr_err("swapon: file is inline\n");
93 return -EINVAL;
94 default:
95 pr_err("swapon: file has unallocated extents\n");
96 return -EINVAL;
97 }
98
99
100 if (iomap->flags & IOMAP_F_DIRTY) {
101 pr_err("swapon: file is not committed\n");
102 return -EINVAL;
103 }
104 if (iomap->flags & IOMAP_F_SHARED) {
105 pr_err("swapon: file has shared extents\n");
106 return -EINVAL;
107 }
108
109
110 if (iomap->bdev != isi->sis->bdev) {
111 pr_err("swapon: file is on multiple devices\n");
112 return -EINVAL;
113 }
114
115 if (isi->iomap.length == 0) {
116
117 memcpy(&isi->iomap, iomap, sizeof(isi->iomap));
118 } else if (isi->iomap.addr + isi->iomap.length == iomap->addr) {
119
120 isi->iomap.length += iomap->length;
121 } else {
122
123 error = iomap_swapfile_add_extent(isi);
124 if (error)
125 return error;
126 memcpy(&isi->iomap, iomap, sizeof(isi->iomap));
127 }
128 return count;
129}
130
131
132
133
134
135int iomap_swapfile_activate(struct swap_info_struct *sis,
136 struct file *swap_file, sector_t *pagespan,
137 const struct iomap_ops *ops)
138{
139 struct iomap_swapfile_info isi = {
140 .sis = sis,
141 .lowest_ppage = (sector_t)-1ULL,
142 };
143 struct address_space *mapping = swap_file->f_mapping;
144 struct inode *inode = mapping->host;
145 loff_t pos = 0;
146 loff_t len = ALIGN_DOWN(i_size_read(inode), PAGE_SIZE);
147 loff_t ret;
148
149
150
151
152
153 ret = vfs_fsync(swap_file, 1);
154 if (ret)
155 return ret;
156
157 while (len > 0) {
158 ret = iomap_apply(inode, pos, len, IOMAP_REPORT,
159 ops, &isi, iomap_swapfile_activate_actor);
160 if (ret <= 0)
161 return ret;
162
163 pos += ret;
164 len -= ret;
165 }
166
167 if (isi.iomap.length) {
168 ret = iomap_swapfile_add_extent(&isi);
169 if (ret)
170 return ret;
171 }
172
173 *pagespan = 1 + isi.highest_ppage - isi.lowest_ppage;
174 sis->max = isi.nr_pages;
175 sis->pages = isi.nr_pages - 1;
176 sis->highest_bit = isi.nr_pages - 1;
177 return isi.nr_extents;
178}
179EXPORT_SYMBOL_GPL(iomap_swapfile_activate);
180