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Commit | Line | Data |
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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 | */ | |
b324814e | 15 | struct page **ceph_get_direct_page_vector(const void __user *data, |
b6aa5901 | 16 | int num_pages, bool write_page) |
3d14c5d2 YS |
17 | { |
18 | struct page **pages; | |
38815b78 SW |
19 | int got = 0; |
20 | int rc = 0; | |
3d14c5d2 YS |
21 | |
22 | pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS); | |
23 | if (!pages) | |
24 | return ERR_PTR(-ENOMEM); | |
25 | ||
26 | down_read(¤t->mm->mmap_sem); | |
38815b78 SW |
27 | while (got < num_pages) { |
28 | rc = get_user_pages(current, current->mm, | |
29 | (unsigned long)data + ((unsigned long)got * PAGE_SIZE), | |
30 | num_pages - got, write_page, 0, pages + got, NULL); | |
31 | if (rc < 0) | |
32 | break; | |
33 | BUG_ON(rc == 0); | |
34 | got += rc; | |
35 | } | |
3d14c5d2 | 36 | up_read(¤t->mm->mmap_sem); |
38815b78 | 37 | if (rc < 0) |
3d14c5d2 YS |
38 | goto fail; |
39 | return pages; | |
40 | ||
41 | fail: | |
38815b78 | 42 | ceph_put_page_vector(pages, got, false); |
3d14c5d2 YS |
43 | return ERR_PTR(rc); |
44 | } | |
45 | EXPORT_SYMBOL(ceph_get_direct_page_vector); | |
46 | ||
b6aa5901 | 47 | void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty) |
3d14c5d2 YS |
48 | { |
49 | int i; | |
50 | ||
b6aa5901 HC |
51 | for (i = 0; i < num_pages; i++) { |
52 | if (dirty) | |
53 | set_page_dirty_lock(pages[i]); | |
3d14c5d2 | 54 | put_page(pages[i]); |
b6aa5901 | 55 | } |
2b777c9d AV |
56 | if (is_vmalloc_addr(pages)) |
57 | vfree(pages); | |
58 | else | |
59 | kfree(pages); | |
3d14c5d2 YS |
60 | } |
61 | EXPORT_SYMBOL(ceph_put_page_vector); | |
62 | ||
63 | void ceph_release_page_vector(struct page **pages, int num_pages) | |
64 | { | |
65 | int i; | |
66 | ||
67 | for (i = 0; i < num_pages; i++) | |
68 | __free_pages(pages[i], 0); | |
69 | kfree(pages); | |
70 | } | |
71 | EXPORT_SYMBOL(ceph_release_page_vector); | |
72 | ||
73 | /* | |
74 | * allocate a vector new pages | |
75 | */ | |
76 | struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags) | |
77 | { | |
78 | struct page **pages; | |
79 | int i; | |
80 | ||
81 | pages = kmalloc(sizeof(*pages) * num_pages, flags); | |
82 | if (!pages) | |
83 | return ERR_PTR(-ENOMEM); | |
84 | for (i = 0; i < num_pages; i++) { | |
85 | pages[i] = __page_cache_alloc(flags); | |
86 | if (pages[i] == NULL) { | |
87 | ceph_release_page_vector(pages, i); | |
88 | return ERR_PTR(-ENOMEM); | |
89 | } | |
90 | } | |
91 | return pages; | |
92 | } | |
93 | EXPORT_SYMBOL(ceph_alloc_page_vector); | |
94 | ||
95 | /* | |
96 | * copy user data into a page vector | |
97 | */ | |
98 | int ceph_copy_user_to_page_vector(struct page **pages, | |
b324814e | 99 | const void __user *data, |
3d14c5d2 YS |
100 | loff_t off, size_t len) |
101 | { | |
102 | int i = 0; | |
103 | int po = off & ~PAGE_CACHE_MASK; | |
104 | int left = len; | |
105 | int l, bad; | |
106 | ||
107 | while (left > 0) { | |
108 | l = min_t(int, PAGE_CACHE_SIZE-po, left); | |
109 | bad = copy_from_user(page_address(pages[i]) + po, data, l); | |
110 | if (bad == l) | |
111 | return -EFAULT; | |
112 | data += l - bad; | |
113 | left -= l - bad; | |
114 | po += l - bad; | |
115 | if (po == PAGE_CACHE_SIZE) { | |
116 | po = 0; | |
117 | i++; | |
118 | } | |
119 | } | |
120 | return len; | |
121 | } | |
122 | EXPORT_SYMBOL(ceph_copy_user_to_page_vector); | |
123 | ||
903bb32e | 124 | void ceph_copy_to_page_vector(struct page **pages, |
b324814e | 125 | const void *data, |
3d14c5d2 YS |
126 | loff_t off, size_t len) |
127 | { | |
128 | int i = 0; | |
129 | size_t po = off & ~PAGE_CACHE_MASK; | |
130 | size_t left = len; | |
3d14c5d2 YS |
131 | |
132 | while (left > 0) { | |
903bb32e AE |
133 | size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left); |
134 | ||
3d14c5d2 YS |
135 | memcpy(page_address(pages[i]) + po, data, l); |
136 | data += l; | |
137 | left -= l; | |
138 | po += l; | |
139 | if (po == PAGE_CACHE_SIZE) { | |
140 | po = 0; | |
141 | i++; | |
142 | } | |
143 | } | |
3d14c5d2 YS |
144 | } |
145 | EXPORT_SYMBOL(ceph_copy_to_page_vector); | |
146 | ||
903bb32e | 147 | void ceph_copy_from_page_vector(struct page **pages, |
b324814e | 148 | void *data, |
3d14c5d2 YS |
149 | loff_t off, size_t len) |
150 | { | |
151 | int i = 0; | |
152 | size_t po = off & ~PAGE_CACHE_MASK; | |
153 | size_t left = len; | |
3d14c5d2 YS |
154 | |
155 | while (left > 0) { | |
903bb32e AE |
156 | size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left); |
157 | ||
3d14c5d2 YS |
158 | memcpy(data, page_address(pages[i]) + po, l); |
159 | data += l; | |
160 | left -= l; | |
161 | po += l; | |
162 | if (po == PAGE_CACHE_SIZE) { | |
163 | po = 0; | |
164 | i++; | |
165 | } | |
166 | } | |
3d14c5d2 YS |
167 | } |
168 | EXPORT_SYMBOL(ceph_copy_from_page_vector); | |
169 | ||
3d14c5d2 YS |
170 | /* |
171 | * Zero an extent within a page vector. Offset is relative to the | |
172 | * start of the first page. | |
173 | */ | |
174 | void ceph_zero_page_vector_range(int off, int len, struct page **pages) | |
175 | { | |
176 | int i = off >> PAGE_CACHE_SHIFT; | |
177 | ||
178 | off &= ~PAGE_CACHE_MASK; | |
179 | ||
180 | dout("zero_page_vector_page %u~%u\n", off, len); | |
181 | ||
182 | /* leading partial page? */ | |
183 | if (off) { | |
184 | int end = min((int)PAGE_CACHE_SIZE, off + len); | |
185 | dout("zeroing %d %p head from %d\n", i, pages[i], | |
186 | (int)off); | |
187 | zero_user_segment(pages[i], off, end); | |
188 | len -= (end - off); | |
189 | i++; | |
190 | } | |
191 | while (len >= PAGE_CACHE_SIZE) { | |
192 | dout("zeroing %d %p len=%d\n", i, pages[i], len); | |
193 | zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE); | |
194 | len -= PAGE_CACHE_SIZE; | |
195 | i++; | |
196 | } | |
197 | /* trailing partial page? */ | |
198 | if (len) { | |
199 | dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len); | |
200 | zero_user_segment(pages[i], 0, len); | |
201 | } | |
202 | } | |
203 | EXPORT_SYMBOL(ceph_zero_page_vector_range); | |
204 |