Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 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, |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame^] | 16 | int num_pages, bool write_page) |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 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, |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame^] | 27 | num_pages, write_page, 0, pages, NULL); |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 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 | |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame^] | 39 | void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty) |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 40 | { |
| 41 | int i; |
| 42 | |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame^] | 43 | for (i = 0; i < num_pages; i++) { |
| 44 | if (dirty) |
| 45 | set_page_dirty_lock(pages[i]); |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 46 | put_page(pages[i]); |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame^] | 47 | } |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 48 | kfree(pages); |
| 49 | } |
| 50 | EXPORT_SYMBOL(ceph_put_page_vector); |
| 51 | |
| 52 | void ceph_release_page_vector(struct page **pages, int num_pages) |
| 53 | { |
| 54 | int i; |
| 55 | |
| 56 | for (i = 0; i < num_pages; i++) |
| 57 | __free_pages(pages[i], 0); |
| 58 | kfree(pages); |
| 59 | } |
| 60 | EXPORT_SYMBOL(ceph_release_page_vector); |
| 61 | |
| 62 | /* |
| 63 | * allocate a vector new pages |
| 64 | */ |
| 65 | struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags) |
| 66 | { |
| 67 | struct page **pages; |
| 68 | int i; |
| 69 | |
| 70 | pages = kmalloc(sizeof(*pages) * num_pages, flags); |
| 71 | if (!pages) |
| 72 | return ERR_PTR(-ENOMEM); |
| 73 | for (i = 0; i < num_pages; i++) { |
| 74 | pages[i] = __page_cache_alloc(flags); |
| 75 | if (pages[i] == NULL) { |
| 76 | ceph_release_page_vector(pages, i); |
| 77 | return ERR_PTR(-ENOMEM); |
| 78 | } |
| 79 | } |
| 80 | return pages; |
| 81 | } |
| 82 | EXPORT_SYMBOL(ceph_alloc_page_vector); |
| 83 | |
| 84 | /* |
| 85 | * copy user data into a page vector |
| 86 | */ |
| 87 | int ceph_copy_user_to_page_vector(struct page **pages, |
| 88 | const char __user *data, |
| 89 | loff_t off, size_t len) |
| 90 | { |
| 91 | int i = 0; |
| 92 | int po = off & ~PAGE_CACHE_MASK; |
| 93 | int left = len; |
| 94 | int l, bad; |
| 95 | |
| 96 | while (left > 0) { |
| 97 | l = min_t(int, PAGE_CACHE_SIZE-po, left); |
| 98 | bad = copy_from_user(page_address(pages[i]) + po, data, l); |
| 99 | if (bad == l) |
| 100 | return -EFAULT; |
| 101 | data += l - bad; |
| 102 | left -= l - bad; |
| 103 | po += l - bad; |
| 104 | if (po == PAGE_CACHE_SIZE) { |
| 105 | po = 0; |
| 106 | i++; |
| 107 | } |
| 108 | } |
| 109 | return len; |
| 110 | } |
| 111 | EXPORT_SYMBOL(ceph_copy_user_to_page_vector); |
| 112 | |
| 113 | int ceph_copy_to_page_vector(struct page **pages, |
| 114 | const char *data, |
| 115 | loff_t off, size_t len) |
| 116 | { |
| 117 | int i = 0; |
| 118 | size_t po = off & ~PAGE_CACHE_MASK; |
| 119 | size_t left = len; |
| 120 | size_t l; |
| 121 | |
| 122 | while (left > 0) { |
| 123 | l = min_t(size_t, PAGE_CACHE_SIZE-po, left); |
| 124 | memcpy(page_address(pages[i]) + po, data, l); |
| 125 | data += l; |
| 126 | left -= l; |
| 127 | po += l; |
| 128 | if (po == PAGE_CACHE_SIZE) { |
| 129 | po = 0; |
| 130 | i++; |
| 131 | } |
| 132 | } |
| 133 | return len; |
| 134 | } |
| 135 | EXPORT_SYMBOL(ceph_copy_to_page_vector); |
| 136 | |
| 137 | int ceph_copy_from_page_vector(struct page **pages, |
| 138 | char *data, |
| 139 | loff_t off, size_t len) |
| 140 | { |
| 141 | int i = 0; |
| 142 | size_t po = off & ~PAGE_CACHE_MASK; |
| 143 | size_t left = len; |
| 144 | size_t l; |
| 145 | |
| 146 | while (left > 0) { |
| 147 | l = min_t(size_t, PAGE_CACHE_SIZE-po, left); |
| 148 | memcpy(data, page_address(pages[i]) + po, l); |
| 149 | data += l; |
| 150 | left -= l; |
| 151 | po += l; |
| 152 | if (po == PAGE_CACHE_SIZE) { |
| 153 | po = 0; |
| 154 | i++; |
| 155 | } |
| 156 | } |
| 157 | return len; |
| 158 | } |
| 159 | EXPORT_SYMBOL(ceph_copy_from_page_vector); |
| 160 | |
| 161 | /* |
| 162 | * copy user data from a page vector into a user pointer |
| 163 | */ |
| 164 | int ceph_copy_page_vector_to_user(struct page **pages, |
| 165 | char __user *data, |
| 166 | loff_t off, size_t len) |
| 167 | { |
| 168 | int i = 0; |
| 169 | int po = off & ~PAGE_CACHE_MASK; |
| 170 | int left = len; |
| 171 | int l, bad; |
| 172 | |
| 173 | while (left > 0) { |
| 174 | l = min_t(int, left, PAGE_CACHE_SIZE-po); |
| 175 | bad = copy_to_user(data, page_address(pages[i]) + po, l); |
| 176 | if (bad == l) |
| 177 | return -EFAULT; |
| 178 | data += l - bad; |
| 179 | left -= l - bad; |
| 180 | if (po) { |
| 181 | po += l - bad; |
| 182 | if (po == PAGE_CACHE_SIZE) |
| 183 | po = 0; |
| 184 | } |
| 185 | i++; |
| 186 | } |
| 187 | return len; |
| 188 | } |
| 189 | EXPORT_SYMBOL(ceph_copy_page_vector_to_user); |
| 190 | |
| 191 | /* |
| 192 | * Zero an extent within a page vector. Offset is relative to the |
| 193 | * start of the first page. |
| 194 | */ |
| 195 | void ceph_zero_page_vector_range(int off, int len, struct page **pages) |
| 196 | { |
| 197 | int i = off >> PAGE_CACHE_SHIFT; |
| 198 | |
| 199 | off &= ~PAGE_CACHE_MASK; |
| 200 | |
| 201 | dout("zero_page_vector_page %u~%u\n", off, len); |
| 202 | |
| 203 | /* leading partial page? */ |
| 204 | if (off) { |
| 205 | int end = min((int)PAGE_CACHE_SIZE, off + len); |
| 206 | dout("zeroing %d %p head from %d\n", i, pages[i], |
| 207 | (int)off); |
| 208 | zero_user_segment(pages[i], off, end); |
| 209 | len -= (end - off); |
| 210 | i++; |
| 211 | } |
| 212 | while (len >= PAGE_CACHE_SIZE) { |
| 213 | dout("zeroing %d %p len=%d\n", i, pages[i], len); |
| 214 | zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE); |
| 215 | len -= PAGE_CACHE_SIZE; |
| 216 | i++; |
| 217 | } |
| 218 | /* trailing partial page? */ |
| 219 | if (len) { |
| 220 | dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len); |
| 221 | zero_user_segment(pages[i], 0, len); |
| 222 | } |
| 223 | } |
| 224 | EXPORT_SYMBOL(ceph_zero_page_vector_range); |
| 225 | |