Patch v3 is the latest one which need to be tested. Please ignore v2.
On 23-Apr-2018 10:59 AM, "kbuild test robot" <lkp@intel.com> wrote:
>
> Hi Souptick,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on v4.17-rc2 next-20180420]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url: https://github.com/0day-ci/linux/commits/Souptick-Joarder/fs-dax-Adding-new-return-type-vm_fault_t/20180423-102814
> config: i386-randconfig-x006-201816 (attached as .config)
> compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
> reproduce:
> # save the attached .config to linux build tree
> make ARCH=i386
>
> All errors (new ones prefixed by >>):
>
> fs/dax.c: In function 'dax_iomap_pte_fault':
> >> fs/dax.c:1265:10: error: implicit declaration of function 'vmf_insert_mixed_mkwrite'; did you mean 'vm_insert_mixed_mkwrite'? [-Werror=implicit-function-declaration]
> ret = vmf_insert_mixed_mkwrite(vma, vaddr, pfn);
> ^~~~~~~~~~~~~~~~~~~~~~~~
> vm_insert_mixed_mkwrite
> cc1: some warnings being treated as errors
>
> vim +1265 fs/dax.c
>
> 1134
> 1135 static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
> 1136 int *iomap_errp, const struct iomap_ops *ops)
> 1137 {
> 1138 struct vm_area_struct *vma = vmf->vma;
> 1139 struct address_space *mapping = vma->vm_file->f_mapping;
> 1140 struct inode *inode = mapping->host;
> 1141 unsigned long vaddr = vmf->address;
> 1142 loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
> 1143 struct iomap iomap = { 0 };
> 1144 unsigned flags = IOMAP_FAULT;
> 1145 int error, major = 0;
> 1146 bool write = vmf->flags & FAULT_FLAG_WRITE;
> 1147 bool sync;
> 1148 vm_fault_t ret = 0;
> 1149 void *entry;
> 1150 pfn_t pfn;
> 1151
> 1152 trace_dax_pte_fault(inode, vmf, ret);
> 1153 /*
> 1154 * Check whether offset isn't beyond end of file now. Caller is supposed
> 1155 * to hold locks serializing us with truncate / punch hole so this is
> 1156 * a reliable test.
> 1157 */
> 1158 if (pos >= i_size_read(inode)) {
> 1159 ret = VM_FAULT_SIGBUS;
> 1160 goto out;
> 1161 }
> 1162
> 1163 if (write && !vmf->cow_page)
> 1164 flags |= IOMAP_WRITE;
> 1165
> 1166 entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
> 1167 if (IS_ERR(entry)) {
> 1168 ret = dax_fault_return(PTR_ERR(entry));
> 1169 goto out;
> 1170 }
> 1171
> 1172 /*
> 1173 * It is possible, particularly with mixed reads & writes to private
> 1174 * mappings, that we have raced with a PMD fault that overlaps with
> 1175 * the PTE we need to set up. If so just return and the fault will be
> 1176 * retried.
> 1177 */
> 1178 if (pmd_trans_huge(*vmf->pmd) || pmd_devmap(*vmf->pmd)) {
> 1179 ret = VM_FAULT_NOPAGE;
> 1180 goto unlock_entry;
> 1181 }
> 1182
> 1183 /*
> 1184 * Note that we don't bother to use iomap_apply here: DAX required
> 1185 * the file system block size to be equal the page size, which means
> 1186 * that we never have to deal with more than a single extent here.
> 1187 */
> 1188 error = ops->iomap_begin(inode, pos, PAGE_SIZE, flags, &iomap);
> 1189 if (iomap_errp)
> 1190 *iomap_errp = error;
> 1191 if (error) {
> 1192 ret = dax_fault_return(error);
> 1193 goto unlock_entry;
> 1194 }
> 1195 if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) {
> 1196 error = -EIO; /* fs corruption? */
> 1197 goto error_finish_iomap;
> 1198 }
> 1199
> 1200 if (vmf->cow_page) {
> 1201 sector_t sector = dax_iomap_sector(&iomap, pos);
> 1202
> 1203 switch (iomap.type) {
> 1204 case IOMAP_HOLE:
> 1205 case IOMAP_UNWRITTEN:
> 1206 clear_user_highpage(vmf->cow_page, vaddr);
> 1207 break;
> 1208 case IOMAP_MAPPED:
> 1209 error = copy_user_dax(iomap.bdev, iomap.dax_dev,
> 1210 sector, PAGE_SIZE, vmf->cow_page, vaddr);
> 1211 break;
> 1212 default:
> 1213 WARN_ON_ONCE(1);
> 1214 error = -EIO;
> 1215 break;
> 1216 }
> 1217
> 1218 if (error)
> 1219 goto error_finish_iomap;
> 1220
> 1221 __SetPageUptodate(vmf->cow_page);
> 1222 ret = finish_fault(vmf);
> 1223 if (!ret)
> 1224 ret = VM_FAULT_DONE_COW;
> 1225 goto finish_iomap;
> 1226 }
> 1227
> 1228 sync = dax_fault_is_synchronous(flags, vma, &iomap);
> 1229
> 1230 switch (iomap.type) {
> 1231 case IOMAP_MAPPED:
> 1232 if (iomap.flags & IOMAP_F_NEW) {
> 1233 count_vm_event(PGMAJFAULT);
> 1234 count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
> 1235 major = VM_FAULT_MAJOR;
> 1236 }
> 1237 error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn);
> 1238 if (error < 0)
> 1239 goto error_finish_iomap;
> 1240
> 1241 entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
> 1242 0, write && !sync);
> 1243 if (IS_ERR(entry)) {
> 1244 error = PTR_ERR(entry);
> 1245 goto error_finish_iomap;
> 1246 }
> 1247
> 1248 /*
> 1249 * If we are doing synchronous page fault and inode needs fsync,
> 1250 * we can insert PTE into page tables only after that happens.
> 1251 * Skip insertion for now and return the pfn so that caller can
> 1252 * insert it after fsync is done.
> 1253 */
> 1254 if (sync) {
> 1255 if (WARN_ON_ONCE(!pfnp)) {
> 1256 error = -EIO;
> 1257 goto error_finish_iomap;
> 1258 }
> 1259 *pfnp = pfn;
> 1260 ret = VM_FAULT_NEEDDSYNC | major;
> 1261 goto finish_iomap;
> 1262 }
> 1263 trace_dax_insert_mapping(inode, vmf, entry);
> 1264 if (write)
> > 1265 ret = vmf_insert_mixed_mkwrite(vma, vaddr, pfn);
> 1266 else
> 1267 ret = vmf_insert_mixed(vma, vaddr, pfn);
> 1268
> 1269 goto finish_iomap;
> 1270 case IOMAP_UNWRITTEN:
> 1271 case IOMAP_HOLE:
> 1272 if (!write) {
> 1273 ret = dax_load_hole(mapping, entry, vmf);
> 1274 goto finish_iomap;
> 1275 }
> 1276 /*FALLTHRU*/
> 1277 default:
> 1278 WARN_ON_ONCE(1);
> 1279 error = -EIO;
> 1280 break;
> 1281 }
> 1282
> 1283 error_finish_iomap:
> 1284 ret = dax_fault_return(error) | major;
> 1285 finish_iomap:
> 1286 if (ops->iomap_end) {
> 1287 int copied = PAGE_SIZE;
> 1288
> 1289 if (ret & VM_FAULT_ERROR)
> 1290 copied = 0;
> 1291 /*
> 1292 * The fault is done by now and there's no way back (other
> 1293 * thread may be already happily using PTE we have installed).
> 1294 * Just ignore error from ->iomap_end since we cannot do much
> 1295 * with it.
> 1296 */
> 1297 ops->iomap_end(inode, pos, PAGE_SIZE, copied, flags, &iomap);
> 1298 }
> 1299 unlock_entry:
> 1300 put_locked_mapping_entry(mapping, vmf->pgoff);
> 1301 out:
> 1302 trace_dax_pte_fault_done(inode, vmf, ret);
> 1303 return ret;
> 1304 }
> 1305
>
> ---
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