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 | */ |
Alex Elder | b324814 | 2013-02-06 13:11:38 -0600 | [diff] [blame^] | 15 | struct page **ceph_get_direct_page_vector(const void __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; |
Sage Weil | 38815b7 | 2011-03-02 16:55:21 -0800 | [diff] [blame] | 19 | int got = 0; |
| 20 | int rc = 0; |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 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); |
Sage Weil | 38815b7 | 2011-03-02 16:55:21 -0800 | [diff] [blame] | 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 | } |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 36 | up_read(¤t->mm->mmap_sem); |
Sage Weil | 38815b7 | 2011-03-02 16:55:21 -0800 | [diff] [blame] | 37 | if (rc < 0) |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 38 | goto fail; |
| 39 | return pages; |
| 40 | |
| 41 | fail: |
Sage Weil | 38815b7 | 2011-03-02 16:55:21 -0800 | [diff] [blame] | 42 | ceph_put_page_vector(pages, got, false); |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 43 | return ERR_PTR(rc); |
| 44 | } |
| 45 | EXPORT_SYMBOL(ceph_get_direct_page_vector); |
| 46 | |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame] | 47 | 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] | 48 | { |
| 49 | int i; |
| 50 | |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame] | 51 | for (i = 0; i < num_pages; i++) { |
| 52 | if (dirty) |
| 53 | set_page_dirty_lock(pages[i]); |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 54 | put_page(pages[i]); |
Henry C Chang | b6aa590 | 2010-12-15 20:45:41 -0800 | [diff] [blame] | 55 | } |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 56 | kfree(pages); |
| 57 | } |
| 58 | EXPORT_SYMBOL(ceph_put_page_vector); |
| 59 | |
| 60 | void ceph_release_page_vector(struct page **pages, int num_pages) |
| 61 | { |
| 62 | int i; |
| 63 | |
| 64 | for (i = 0; i < num_pages; i++) |
| 65 | __free_pages(pages[i], 0); |
| 66 | kfree(pages); |
| 67 | } |
| 68 | EXPORT_SYMBOL(ceph_release_page_vector); |
| 69 | |
| 70 | /* |
| 71 | * allocate a vector new pages |
| 72 | */ |
| 73 | struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags) |
| 74 | { |
| 75 | struct page **pages; |
| 76 | int i; |
| 77 | |
| 78 | pages = kmalloc(sizeof(*pages) * num_pages, flags); |
| 79 | if (!pages) |
| 80 | return ERR_PTR(-ENOMEM); |
| 81 | for (i = 0; i < num_pages; i++) { |
| 82 | pages[i] = __page_cache_alloc(flags); |
| 83 | if (pages[i] == NULL) { |
| 84 | ceph_release_page_vector(pages, i); |
| 85 | return ERR_PTR(-ENOMEM); |
| 86 | } |
| 87 | } |
| 88 | return pages; |
| 89 | } |
| 90 | EXPORT_SYMBOL(ceph_alloc_page_vector); |
| 91 | |
| 92 | /* |
| 93 | * copy user data into a page vector |
| 94 | */ |
| 95 | int ceph_copy_user_to_page_vector(struct page **pages, |
Alex Elder | b324814 | 2013-02-06 13:11:38 -0600 | [diff] [blame^] | 96 | const void __user *data, |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 97 | loff_t off, size_t len) |
| 98 | { |
| 99 | int i = 0; |
| 100 | int po = off & ~PAGE_CACHE_MASK; |
| 101 | int left = len; |
| 102 | int l, bad; |
| 103 | |
| 104 | while (left > 0) { |
| 105 | l = min_t(int, PAGE_CACHE_SIZE-po, left); |
| 106 | bad = copy_from_user(page_address(pages[i]) + po, data, l); |
| 107 | if (bad == l) |
| 108 | return -EFAULT; |
| 109 | data += l - bad; |
| 110 | left -= l - bad; |
| 111 | po += l - bad; |
| 112 | if (po == PAGE_CACHE_SIZE) { |
| 113 | po = 0; |
| 114 | i++; |
| 115 | } |
| 116 | } |
| 117 | return len; |
| 118 | } |
| 119 | EXPORT_SYMBOL(ceph_copy_user_to_page_vector); |
| 120 | |
| 121 | int ceph_copy_to_page_vector(struct page **pages, |
Alex Elder | b324814 | 2013-02-06 13:11:38 -0600 | [diff] [blame^] | 122 | const void *data, |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 123 | loff_t off, size_t len) |
| 124 | { |
| 125 | int i = 0; |
| 126 | size_t po = off & ~PAGE_CACHE_MASK; |
| 127 | size_t left = len; |
| 128 | size_t l; |
| 129 | |
| 130 | while (left > 0) { |
| 131 | l = min_t(size_t, PAGE_CACHE_SIZE-po, left); |
| 132 | memcpy(page_address(pages[i]) + po, data, l); |
| 133 | data += l; |
| 134 | left -= l; |
| 135 | po += l; |
| 136 | if (po == PAGE_CACHE_SIZE) { |
| 137 | po = 0; |
| 138 | i++; |
| 139 | } |
| 140 | } |
| 141 | return len; |
| 142 | } |
| 143 | EXPORT_SYMBOL(ceph_copy_to_page_vector); |
| 144 | |
| 145 | int ceph_copy_from_page_vector(struct page **pages, |
Alex Elder | b324814 | 2013-02-06 13:11:38 -0600 | [diff] [blame^] | 146 | void *data, |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 147 | loff_t off, size_t len) |
| 148 | { |
| 149 | int i = 0; |
| 150 | size_t po = off & ~PAGE_CACHE_MASK; |
| 151 | size_t left = len; |
| 152 | size_t l; |
| 153 | |
| 154 | while (left > 0) { |
| 155 | l = min_t(size_t, PAGE_CACHE_SIZE-po, left); |
| 156 | memcpy(data, page_address(pages[i]) + po, l); |
| 157 | data += l; |
| 158 | left -= l; |
| 159 | po += l; |
| 160 | if (po == PAGE_CACHE_SIZE) { |
| 161 | po = 0; |
| 162 | i++; |
| 163 | } |
| 164 | } |
| 165 | return len; |
| 166 | } |
| 167 | EXPORT_SYMBOL(ceph_copy_from_page_vector); |
| 168 | |
| 169 | /* |
| 170 | * copy user data from a page vector into a user pointer |
| 171 | */ |
| 172 | int ceph_copy_page_vector_to_user(struct page **pages, |
Alex Elder | b324814 | 2013-02-06 13:11:38 -0600 | [diff] [blame^] | 173 | void __user *data, |
Yehuda Sadeh | 3d14c5d | 2010-04-06 15:14:15 -0700 | [diff] [blame] | 174 | loff_t off, size_t len) |
| 175 | { |
| 176 | int i = 0; |
| 177 | int po = off & ~PAGE_CACHE_MASK; |
| 178 | int left = len; |
| 179 | int l, bad; |
| 180 | |
| 181 | while (left > 0) { |
| 182 | l = min_t(int, left, PAGE_CACHE_SIZE-po); |
| 183 | bad = copy_to_user(data, page_address(pages[i]) + po, l); |
| 184 | if (bad == l) |
| 185 | return -EFAULT; |
| 186 | data += l - bad; |
| 187 | left -= l - bad; |
| 188 | if (po) { |
| 189 | po += l - bad; |
| 190 | if (po == PAGE_CACHE_SIZE) |
| 191 | po = 0; |
| 192 | } |
| 193 | i++; |
| 194 | } |
| 195 | return len; |
| 196 | } |
| 197 | EXPORT_SYMBOL(ceph_copy_page_vector_to_user); |
| 198 | |
| 199 | /* |
| 200 | * Zero an extent within a page vector. Offset is relative to the |
| 201 | * start of the first page. |
| 202 | */ |
| 203 | void ceph_zero_page_vector_range(int off, int len, struct page **pages) |
| 204 | { |
| 205 | int i = off >> PAGE_CACHE_SHIFT; |
| 206 | |
| 207 | off &= ~PAGE_CACHE_MASK; |
| 208 | |
| 209 | dout("zero_page_vector_page %u~%u\n", off, len); |
| 210 | |
| 211 | /* leading partial page? */ |
| 212 | if (off) { |
| 213 | int end = min((int)PAGE_CACHE_SIZE, off + len); |
| 214 | dout("zeroing %d %p head from %d\n", i, pages[i], |
| 215 | (int)off); |
| 216 | zero_user_segment(pages[i], off, end); |
| 217 | len -= (end - off); |
| 218 | i++; |
| 219 | } |
| 220 | while (len >= PAGE_CACHE_SIZE) { |
| 221 | dout("zeroing %d %p len=%d\n", i, pages[i], len); |
| 222 | zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE); |
| 223 | len -= PAGE_CACHE_SIZE; |
| 224 | i++; |
| 225 | } |
| 226 | /* trailing partial page? */ |
| 227 | if (len) { |
| 228 | dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len); |
| 229 | zero_user_segment(pages[i], 0, len); |
| 230 | } |
| 231 | } |
| 232 | EXPORT_SYMBOL(ceph_zero_page_vector_range); |
| 233 | |