Re: [RFC PATCH 2/4] namespacefs: Add methods to create/remove PID namespace directories

[kernel test robot <lkp@intel.com>]

[-- Attachment #1: Type: text/plain, Size: 7168 bytes --]

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/namespacefs-Proof-of-Concept/20211119-021813
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/9b9ee11c1c806bd636fd81cd55b93f2034f0d1a0
        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@intel.com>

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)
         |      ^~~~~~~~~~~~~~~~~~~~~~
>> fs/namespacefs/inode.c:286:5: warning: no previous prototype for 'namespacefs_create_pid_ns_dir' [-Wmissing-prototypes]
     286 | int namespacefs_create_pid_ns_dir(struct pid_namespace *ns)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> fs/namespacefs/inode.c:305:6: warning: no previous prototype for 'namespacefs_remove_pid_ns_dir' [-Wmissing-prototypes]
     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 *
 > 161	namespacefs_create_file(const char *name, struct dentry *parent,
   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 *
 > 170	namespacefs_create_dir(const char *name, struct dentry *parent,
   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	
 > 286	int namespacefs_create_pid_ns_dir(struct pid_namespace *ns)
   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	
 > 305	void namespacefs_remove_pid_ns_dir(struct pid_namespace *ns)
   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(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 62413 bytes --]