Hi "Yordan, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on linux/master] [also build test WARNING on hnaz-mm/master linus/master v5.16-rc1 next-20211118] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Yordan-Karadzhov-VMware/namespac... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 8ab774587903771821b59471cc723bba6d893942 config: m68k-allyesconfig (attached as .config) compiler: m68k-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/9b9ee11c1c806bd636fd81cd55b93f203... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Yordan-Karadzhov-VMware/namespacefs-Proof-of-Concept/20211119-021813 git checkout 9b9ee11c1c806bd636fd81cd55b93f2034f0d1a0 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=m68k If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): fs/namespacefs/inode.c:161:1: warning: no previous prototype for 'namespacefs_create_file' [-Wmissing-prototypes] 161 | namespacefs_create_file(const char *name, struct dentry *parent, | ^~~~~~~~~~~~~~~~~~~~~~~ fs/namespacefs/inode.c:170:1: warning: no previous prototype for 'namespacefs_create_dir' [-Wmissing-prototypes] 170 | namespacefs_create_dir(const char *name, struct dentry *parent, | ^~~~~~~~~~~~~~~~~~~~~~ fs/namespacefs/inode.c:181:6: warning: no previous prototype for 'namespacefs_remove_dir' [-Wmissing-prototypes] 181 | void namespacefs_remove_dir(struct dentry *dentry) | ^~~~~~~~~~~~~~~~~~~~~~ 286 | int namespacefs_create_pid_ns_dir(struct pid_namespace *ns) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 305 | void namespacefs_remove_pid_ns_dir(struct pid_namespace *ns) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/namespacefs_create_pid_ns_dir +286 fs/namespacefs/inode.c 159 160 struct dentry * 162 const struct user_namespace *user_ns, 163 const struct file_operations *fops, 164 void *data) 165 { 166 return create(name, parent, user_ns, fops, data); 167 } 168 169 struct dentry * 171 const struct user_namespace *user_ns) 172 { 173 return create(name, parent, user_ns, NULL, NULL); 174 } 175 176 static void remove_one(struct dentry *d) 177 { 178 release_namespacefs(); 179 } 180 181 void namespacefs_remove_dir(struct dentry *dentry) 182 { 183 if (IS_ERR_OR_NULL(dentry)) 184 return; 185 186 if (pin_fs()) 187 return; 188 189 simple_recursive_removal(dentry, remove_one); 190 release_namespacefs(); 191 } 192 193 struct idr_seq_context { 194 struct idr *idr; 195 int index; 196 }; 197 198 static void *idr_seq_get_next(struct idr_seq_context *idr_ctx, loff_t *pos) 199 { 200 void *next = idr_get_next(idr_ctx->idr, &idr_ctx->index); 201 202 *pos = ++idr_ctx->index; 203 return next; 204 } 205 206 static void *idr_seq_start(struct seq_file *m, loff_t *pos) 207 { 208 struct idr_seq_context *idr_ctx = m->private; 209 210 idr_lock(idr_ctx->idr); 211 idr_ctx->index = *pos; 212 return idr_seq_get_next(idr_ctx, pos); 213 } 214 215 static void *idr_seq_next(struct seq_file *m, void *v, loff_t *pos) 216 { 217 return idr_seq_get_next(m->private, pos); 218 } 219 220 static void idr_seq_stop(struct seq_file *m, void *p) 221 { 222 struct idr_seq_context *idr_ctx = m->private; 223 224 idr_unlock(idr_ctx->idr); 225 } 226 227 static int idr_seq_open(struct file *file, struct idr *idr, 228 const struct seq_operations *ops) 229 { 230 struct idr_seq_context *idr_ctx; 231 232 idr_ctx = __seq_open_private(file, ops, sizeof(*idr_ctx)); 233 if (!idr_ctx) 234 return -ENOMEM; 235 236 idr_ctx->idr = idr; 237 238 return 0; 239 } 240 241 static inline int pid_seq_show(struct seq_file *m, void *v) 242 { 243 struct pid *pid = v; 244 245 seq_printf(m, "%d\n", pid_nr(pid)); 246 return 0; 247 } 248 249 static const struct seq_operations pid_seq_ops = { 250 .start = idr_seq_start, 251 .next = idr_seq_next, 252 .stop = idr_seq_stop, 253 .show = pid_seq_show, 254 }; 255 256 static int pid_seq_open(struct inode *inode, struct file *file) 257 { 258 struct idr *idr = inode->i_private; 259 260 return idr_seq_open(file, idr, &pid_seq_ops); 261 } 262 263 static const struct file_operations tasks_fops = { 264 .open = pid_seq_open, 265 .read = seq_read, 266 .llseek = seq_lseek, 267 .release = seq_release_private, 268 }; 269 270 static int create_inode_dir(struct ns_common *ns, struct dentry *parent_dentry, 271 const struct user_namespace *user_ns) 272 { 273 char *dir = kasprintf(GFP_KERNEL, "%u", ns->inum); 274 275 if (!dir) 276 return -ENOMEM; 277 278 ns->dentry = namespacefs_create_dir(dir, parent_dentry, user_ns); 279 kfree(dir); 280 if (IS_ERR(ns->dentry)) 281 return PTR_ERR(ns->dentry); 282 283 return 0; 284 } 285 287 { 288 struct dentry *dentry; 289 int err; 290 291 err = create_inode_dir(&ns->ns, ns->parent->ns.dentry, ns->user_ns); 292 if (err) 293 return err; 294 295 dentry = namespacefs_create_file("tasks", ns->ns.dentry, ns->user_ns, 296 &tasks_fops, &ns->idr); 297 if (IS_ERR(dentry)) { 298 dput(ns->ns.dentry); 299 return PTR_ERR(dentry); 300 } 301 302 return 0; 303 } 304 306 { 307 namespacefs_remove_dir(ns->ns.dentry); 308 } 309 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org