1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
#include <linux/ceph/ceph_debug.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/writeback.h>
#include <linux/ceph/libceph.h>
/*
* build a vector of user pages
*/
struct page **ceph_get_direct_page_vector(const void __user *data,
int num_pages, bool write_page)
{
struct page **pages;
int got = 0;
int rc = 0;
pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
if (!pages)
return ERR_PTR(-ENOMEM);
down_read(¤t->mm->mmap_sem);
while (got < num_pages) {
rc = get_user_pages(current, current->mm,
(unsigned long)data + ((unsigned long)got * PAGE_SIZE),
num_pages - got, write_page, 0, pages + got, NULL);
if (rc < 0)
break;
BUG_ON(rc == 0);
got += rc;
}
up_read(¤t->mm->mmap_sem);
if (rc < 0)
goto fail;
return pages;
fail:
ceph_put_page_vector(pages, got, false);
return ERR_PTR(rc);
}
EXPORT_SYMBOL(ceph_get_direct_page_vector);
void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
{
int i;
for (i = 0; i < num_pages; i++) {
if (dirty)
set_page_dirty_lock(pages[i]);
put_page(pages[i]);
}
kfree(pages);
}
EXPORT_SYMBOL(ceph_put_page_vector);
void ceph_release_page_vector(struct page **pages, int num_pages)
{
int i;
for (i = 0; i < num_pages; i++)
__free_pages(pages[i], 0);
kfree(pages);
}
EXPORT_SYMBOL(ceph_release_page_vector);
/*
* allocate a vector new pages
*/
struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
{
struct page **pages;
int i;
pages = kmalloc(sizeof(*pages) * num_pages, flags);
if (!pages)
return ERR_PTR(-ENOMEM);
for (i = 0; i < num_pages; i++) {
pages[i] = __page_cache_alloc(flags);
if (pages[i] == NULL) {
ceph_release_page_vector(pages, i);
return ERR_PTR(-ENOMEM);
}
}
return pages;
}
EXPORT_SYMBOL(ceph_alloc_page_vector);
/*
* copy user data into a page vector
*/
int ceph_copy_user_to_page_vector(struct page **pages,
const void __user *data,
loff_t off, size_t len)
{
int i = 0;
int po = off & ~PAGE_CACHE_MASK;
int left = len;
int l, bad;
while (left > 0) {
l = min_t(int, PAGE_CACHE_SIZE-po, left);
bad = copy_from_user(page_address(pages[i]) + po, data, l);
if (bad == l)
return -EFAULT;
data += l - bad;
left -= l - bad;
po += l - bad;
if (po == PAGE_CACHE_SIZE) {
po = 0;
i++;
}
}
return len;
}
EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
int ceph_copy_to_page_vector(struct page **pages,
const void *data,
loff_t off, size_t len)
{
int i = 0;
size_t po = off & ~PAGE_CACHE_MASK;
size_t left = len;
size_t l;
while (left > 0) {
l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
memcpy(page_address(pages[i]) + po, data, l);
data += l;
left -= l;
po += l;
if (po == PAGE_CACHE_SIZE) {
po = 0;
i++;
}
}
return len;
}
EXPORT_SYMBOL(ceph_copy_to_page_vector);
int ceph_copy_from_page_vector(struct page **pages,
void *data,
loff_t off, size_t len)
{
int i = 0;
size_t po = off & ~PAGE_CACHE_MASK;
size_t left = len;
size_t l;
while (left > 0) {
l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
memcpy(data, page_address(pages[i]) + po, l);
data += l;
left -= l;
po += l;
if (po == PAGE_CACHE_SIZE) {
po = 0;
i++;
}
}
return len;
}
EXPORT_SYMBOL(ceph_copy_from_page_vector);
/*
* copy user data from a page vector into a user pointer
*/
int ceph_copy_page_vector_to_user(struct page **pages,
void __user *data,
loff_t off, size_t len)
{
int i = 0;
int po = off & ~PAGE_CACHE_MASK;
int left = len;
int l, bad;
while (left > 0) {
l = min_t(int, left, PAGE_CACHE_SIZE-po);
bad = copy_to_user(data, page_address(pages[i]) + po, l);
if (bad == l)
return -EFAULT;
data += l - bad;
left -= l - bad;
if (po) {
po += l - bad;
if (po == PAGE_CACHE_SIZE)
po = 0;
}
i++;
}
return len;
}
EXPORT_SYMBOL(ceph_copy_page_vector_to_user);
/*
* Zero an extent within a page vector. Offset is relative to the
* start of the first page.
*/
void ceph_zero_page_vector_range(int off, int len, struct page **pages)
{
int i = off >> PAGE_CACHE_SHIFT;
off &= ~PAGE_CACHE_MASK;
dout("zero_page_vector_page %u~%u\n", off, len);
/* leading partial page? */
if (off) {
int end = min((int)PAGE_CACHE_SIZE, off + len);
dout("zeroing %d %p head from %d\n", i, pages[i],
(int)off);
zero_user_segment(pages[i], off, end);
len -= (end - off);
i++;
}
while (len >= PAGE_CACHE_SIZE) {
dout("zeroing %d %p len=%d\n", i, pages[i], len);
zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
len -= PAGE_CACHE_SIZE;
i++;
}
/* trailing partial page? */
if (len) {
dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
zero_user_segment(pages[i], 0, len);
}
}
EXPORT_SYMBOL(ceph_zero_page_vector_range);
|
