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