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 down_read(¤t->mm->mmap_sem); 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 } 36 up_read(¤t->mm->mmap_sem); 37 if (rc < 0) 38 goto fail; 39 return pages; 40 41 fail: 42 ceph_put_page_vector(pages, got, false); 43 return ERR_PTR(rc); 44 } 45 EXPORT_SYMBOL(ceph_get_direct_page_vector); 46 47 void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty) 48 { 49 int i; 50 51 for (i = 0; i < num_pages; i++) { 52 if (dirty) 53 set_page_dirty_lock(pages[i]); 54 put_page(pages[i]); 55 } 56 if (is_vmalloc_addr(pages)) 57 vfree(pages); 58 else 59 kfree(pages); 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, 99 const void __user *data, 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); 123 124 void ceph_copy_to_page_vector(struct page **pages, 125 const void *data, 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; 131 132 while (left > 0) { 133 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left); 134 135 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 } 144 } 145 EXPORT_SYMBOL(ceph_copy_to_page_vector); 146 147 void ceph_copy_from_page_vector(struct page **pages, 148 void *data, 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; 154 155 while (left > 0) { 156 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left); 157 158 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 } 167 } 168 EXPORT_SYMBOL(ceph_copy_from_page_vector); 169 170 /* 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); 204 205