Commit | Line | Data |
---|---|---|
3d14c5d2 YS |
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 char __user *data, | |
e98b6fed | 16 | int num_pages) |
3d14c5d2 YS |
17 | { |
18 | struct page **pages; | |
19 | int rc; | |
20 | ||
21 | pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS); | |
22 | if (!pages) | |
23 | return ERR_PTR(-ENOMEM); | |
24 | ||
25 | down_read(¤t->mm->mmap_sem); | |
26 | rc = get_user_pages(current, current->mm, (unsigned long)data, | |
27 | num_pages, 0, 0, pages, NULL); | |
28 | up_read(¤t->mm->mmap_sem); | |
29 | if (rc < 0) | |
30 | goto fail; | |
31 | return pages; | |
32 | ||
33 | fail: | |
34 | kfree(pages); | |
35 | return ERR_PTR(rc); | |
36 | } | |
37 | EXPORT_SYMBOL(ceph_get_direct_page_vector); | |
38 | ||
39 | void ceph_put_page_vector(struct page **pages, int num_pages) | |
40 | { | |
41 | int i; | |
42 | ||
43 | for (i = 0; i < num_pages; i++) | |
44 | put_page(pages[i]); | |
45 | kfree(pages); | |
46 | } | |
47 | EXPORT_SYMBOL(ceph_put_page_vector); | |
48 | ||
49 | void ceph_release_page_vector(struct page **pages, int num_pages) | |
50 | { | |
51 | int i; | |
52 | ||
53 | for (i = 0; i < num_pages; i++) | |
54 | __free_pages(pages[i], 0); | |
55 | kfree(pages); | |
56 | } | |
57 | EXPORT_SYMBOL(ceph_release_page_vector); | |
58 | ||
59 | /* | |
60 | * allocate a vector new pages | |
61 | */ | |
62 | struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags) | |
63 | { | |
64 | struct page **pages; | |
65 | int i; | |
66 | ||
67 | pages = kmalloc(sizeof(*pages) * num_pages, flags); | |
68 | if (!pages) | |
69 | return ERR_PTR(-ENOMEM); | |
70 | for (i = 0; i < num_pages; i++) { | |
71 | pages[i] = __page_cache_alloc(flags); | |
72 | if (pages[i] == NULL) { | |
73 | ceph_release_page_vector(pages, i); | |
74 | return ERR_PTR(-ENOMEM); | |
75 | } | |
76 | } | |
77 | return pages; | |
78 | } | |
79 | EXPORT_SYMBOL(ceph_alloc_page_vector); | |
80 | ||
81 | /* | |
82 | * copy user data into a page vector | |
83 | */ | |
84 | int ceph_copy_user_to_page_vector(struct page **pages, | |
85 | const char __user *data, | |
86 | loff_t off, size_t len) | |
87 | { | |
88 | int i = 0; | |
89 | int po = off & ~PAGE_CACHE_MASK; | |
90 | int left = len; | |
91 | int l, bad; | |
92 | ||
93 | while (left > 0) { | |
94 | l = min_t(int, PAGE_CACHE_SIZE-po, left); | |
95 | bad = copy_from_user(page_address(pages[i]) + po, data, l); | |
96 | if (bad == l) | |
97 | return -EFAULT; | |
98 | data += l - bad; | |
99 | left -= l - bad; | |
100 | po += l - bad; | |
101 | if (po == PAGE_CACHE_SIZE) { | |
102 | po = 0; | |
103 | i++; | |
104 | } | |
105 | } | |
106 | return len; | |
107 | } | |
108 | EXPORT_SYMBOL(ceph_copy_user_to_page_vector); | |
109 | ||
110 | int ceph_copy_to_page_vector(struct page **pages, | |
111 | const char *data, | |
112 | loff_t off, size_t len) | |
113 | { | |
114 | int i = 0; | |
115 | size_t po = off & ~PAGE_CACHE_MASK; | |
116 | size_t left = len; | |
117 | size_t l; | |
118 | ||
119 | while (left > 0) { | |
120 | l = min_t(size_t, PAGE_CACHE_SIZE-po, left); | |
121 | memcpy(page_address(pages[i]) + po, data, l); | |
122 | data += l; | |
123 | left -= l; | |
124 | po += l; | |
125 | if (po == PAGE_CACHE_SIZE) { | |
126 | po = 0; | |
127 | i++; | |
128 | } | |
129 | } | |
130 | return len; | |
131 | } | |
132 | EXPORT_SYMBOL(ceph_copy_to_page_vector); | |
133 | ||
134 | int ceph_copy_from_page_vector(struct page **pages, | |
135 | char *data, | |
136 | loff_t off, size_t len) | |
137 | { | |
138 | int i = 0; | |
139 | size_t po = off & ~PAGE_CACHE_MASK; | |
140 | size_t left = len; | |
141 | size_t l; | |
142 | ||
143 | while (left > 0) { | |
144 | l = min_t(size_t, PAGE_CACHE_SIZE-po, left); | |
145 | memcpy(data, page_address(pages[i]) + po, l); | |
146 | data += l; | |
147 | left -= l; | |
148 | po += l; | |
149 | if (po == PAGE_CACHE_SIZE) { | |
150 | po = 0; | |
151 | i++; | |
152 | } | |
153 | } | |
154 | return len; | |
155 | } | |
156 | EXPORT_SYMBOL(ceph_copy_from_page_vector); | |
157 | ||
158 | /* | |
159 | * copy user data from a page vector into a user pointer | |
160 | */ | |
161 | int ceph_copy_page_vector_to_user(struct page **pages, | |
162 | char __user *data, | |
163 | loff_t off, size_t len) | |
164 | { | |
165 | int i = 0; | |
166 | int po = off & ~PAGE_CACHE_MASK; | |
167 | int left = len; | |
168 | int l, bad; | |
169 | ||
170 | while (left > 0) { | |
171 | l = min_t(int, left, PAGE_CACHE_SIZE-po); | |
172 | bad = copy_to_user(data, page_address(pages[i]) + po, l); | |
173 | if (bad == l) | |
174 | return -EFAULT; | |
175 | data += l - bad; | |
176 | left -= l - bad; | |
177 | if (po) { | |
178 | po += l - bad; | |
179 | if (po == PAGE_CACHE_SIZE) | |
180 | po = 0; | |
181 | } | |
182 | i++; | |
183 | } | |
184 | return len; | |
185 | } | |
186 | EXPORT_SYMBOL(ceph_copy_page_vector_to_user); | |
187 | ||
188 | /* | |
189 | * Zero an extent within a page vector. Offset is relative to the | |
190 | * start of the first page. | |
191 | */ | |
192 | void ceph_zero_page_vector_range(int off, int len, struct page **pages) | |
193 | { | |
194 | int i = off >> PAGE_CACHE_SHIFT; | |
195 | ||
196 | off &= ~PAGE_CACHE_MASK; | |
197 | ||
198 | dout("zero_page_vector_page %u~%u\n", off, len); | |
199 | ||
200 | /* leading partial page? */ | |
201 | if (off) { | |
202 | int end = min((int)PAGE_CACHE_SIZE, off + len); | |
203 | dout("zeroing %d %p head from %d\n", i, pages[i], | |
204 | (int)off); | |
205 | zero_user_segment(pages[i], off, end); | |
206 | len -= (end - off); | |
207 | i++; | |
208 | } | |
209 | while (len >= PAGE_CACHE_SIZE) { | |
210 | dout("zeroing %d %p len=%d\n", i, pages[i], len); | |
211 | zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE); | |
212 | len -= PAGE_CACHE_SIZE; | |
213 | i++; | |
214 | } | |
215 | /* trailing partial page? */ | |
216 | if (len) { | |
217 | dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len); | |
218 | zero_user_segment(pages[i], 0, len); | |
219 | } | |
220 | } | |
221 | EXPORT_SYMBOL(ceph_zero_page_vector_range); | |
222 |