Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs cleanups from Al Viro:
"Assorted cleanups and fixes all over the place"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
coredump: only charge written data against RLIMIT_CORE
coredump: get rid of coredump_params->written
ecryptfs_lookup(): try either only encrypted or plaintext name
ecryptfs: avoid multiple aliases for directories
bpf: reject invalid names right in ->lookup()
__d_alloc(): treat NULL name as QSTR("/", 1)
mtd: switch ubi_open_volume_path() to vfs_stat()
mtd: switch open_mtd_by_chdev() to use of vfs_stat()

arch/powerpc/platforms/cell/spufs/coredump.c

···
 	char *name;
 	char fullname[80], *buf;
 	struct elf_note en;
+	size_t skip;
 
 	buf = (void *)get_zeroed_page(GFP_KERNEL);
 	if (!buf)
···
 	if (rc < 0)
 		goto out;
 
-	if (!dump_skip(cprm,
-		       roundup(cprm->written - total + sz, 4) - cprm->written))
+	skip = roundup(cprm->file->f_pos - total + sz, 4) - cprm->file->f_pos;
+	if (!dump_skip(cprm, skip))
 		goto Eio;
 out:
 	free_page((unsigned long)buf);

drivers/mtd/ubi/build.c

···
  */
 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
 {
-	int err, major, minor, mode;
-	struct path path;
+	struct kstat stat;
+	int err, minor;
 
 	/* Probably this is an MTD character device node path */
-	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
+	err = vfs_stat(mtd_dev, &stat);
 	if (err)
 		return ERR_PTR(err);
 
 	/* MTD device number is defined by the major / minor numbers */
-	major = imajor(d_backing_inode(path.dentry));
-	minor = iminor(d_backing_inode(path.dentry));
-	mode = d_backing_inode(path.dentry)->i_mode;
-	path_put(&path);
-	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
+	if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
 		return ERR_PTR(-EINVAL);
 
+	minor = MINOR(stat.rdev);
 	if (minor & 1)
 		/*
 		 * Just do not think the "/dev/mtdrX" devices support is need,

drivers/mtd/ubi/kapi.c

···
  */
 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
 {
-	int error, ubi_num, vol_id, mod;
-	struct inode *inode;
-	struct path path;
+	int error, ubi_num, vol_id;
+	struct kstat stat;
 
 	dbg_gen("open volume %s, mode %d", pathname, mode);
 
 	if (!pathname || !*pathname)
 		return ERR_PTR(-EINVAL);
 
-	error = kern_path(pathname, LOOKUP_FOLLOW, &path);
+	error = vfs_stat(pathname, &stat);
 	if (error)
 		return ERR_PTR(error);
 
-	inode = d_backing_inode(path.dentry);
-	mod = inode->i_mode;
-	ubi_num = ubi_major2num(imajor(inode));
-	vol_id = iminor(inode) - 1;
-	path_put(&path);
-
-	if (!S_ISCHR(mod))
+	if (!S_ISCHR(stat.mode))
 		return ERR_PTR(-EINVAL);
+
+	ubi_num = ubi_major2num(MAJOR(stat.rdev));
+	vol_id = MINOR(stat.rdev) - 1;
+
 	if (vol_id >= 0 && ubi_num >= 0)
 		return ubi_open_volume(ubi_num, vol_id, mode);
 	return ERR_PTR(-ENODEV);

fs/binfmt_elf.c

···
 		goto end_coredump;
 
 	/* Align to page */
-	if (!dump_skip(cprm, dataoff - cprm->written))
+	if (!dump_skip(cprm, dataoff - cprm->file->f_pos))
 		goto end_coredump;
 
 	for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;

fs/binfmt_elf_fdpic.c

···
 				goto end_coredump;
 	}
 
-	if (!dump_skip(cprm, dataoff - cprm->written))
+	if (!dump_skip(cprm, dataoff - cprm->file->f_pos))
 		goto end_coredump;
 
 	if (!elf_fdpic_dump_segments(cprm))

fs/coredump.c

···
 	static char zeroes[PAGE_SIZE];
 	struct file *file = cprm->file;
 	if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
-		if (cprm->written + nr > cprm->limit)
-			return 0;
 		if (dump_interrupted() ||
 		    file->f_op->llseek(file, nr, SEEK_CUR) < 0)
 			return 0;
-		cprm->written += nr;
 		return 1;
 	} else {
 		while (nr > PAGE_SIZE) {
···
 
 int dump_align(struct coredump_params *cprm, int align)
 {
-	unsigned mod = cprm->written & (align - 1);
+	unsigned mod = cprm->file->f_pos & (align - 1);
 	if (align & (align - 1))
 		return 0;
 	return mod ? dump_skip(cprm, align - mod) : 1;

fs/dcache.c

···
 	 * be overwriting an internal NUL character
 	 */
 	dentry->d_iname[DNAME_INLINE_LEN-1] = 0;
-	if (name->len > DNAME_INLINE_LEN-1) {
+	if (unlikely(!name)) {
+		static const struct qstr anon = QSTR_INIT("/", 1);
+		name = &anon;
+		dname = dentry->d_iname;
+	} else if (name->len > DNAME_INLINE_LEN-1) {
 		size_t size = offsetof(struct external_name, name[1]);
 		struct external_name *p = kmalloc(size + name->len,
 						  GFP_KERNEL_ACCOUNT);
···
 	struct dentry *res = NULL;
 
 	if (root_inode) {
-		static const struct qstr name = QSTR_INIT("/", 1);
-
-		res = __d_alloc(root_inode->i_sb, &name);
+		res = __d_alloc(root_inode->i_sb, NULL);
 		if (res)
 			d_instantiate(res, root_inode);
 		else
···
 
 static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
 {
-	static const struct qstr anonstring = QSTR_INIT("/", 1);
 	struct dentry *tmp;
 	struct dentry *res;
 	unsigned add_flags;
···
 	if (res)
 		goto out_iput;
 
-	tmp = __d_alloc(inode->i_sb, &anonstring);
+	tmp = __d_alloc(inode->i_sb, NULL);
 	if (!tmp) {
 		res = ERR_PTR(-ENOMEM);
 		goto out_iput;

fs/ecryptfs/inode.c

···
 /**
  * ecryptfs_lookup_interpose - Dentry interposition for a lookup
  */
-static int ecryptfs_lookup_interpose(struct dentry *dentry,
-				     struct dentry *lower_dentry,
-				     struct inode *dir_inode)
+static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
+				     struct dentry *lower_dentry)
 {
 	struct inode *inode, *lower_inode = d_inode(lower_dentry);
 	struct ecryptfs_dentry_info *dentry_info;
···
 		       "to allocate ecryptfs_dentry_info struct\n",
 			__func__);
 		dput(lower_dentry);
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
-	fsstack_copy_attr_atime(dir_inode, d_inode(lower_dentry->d_parent));
+	fsstack_copy_attr_atime(d_inode(dentry->d_parent),
+				d_inode(lower_dentry->d_parent));
 	BUG_ON(!d_count(lower_dentry));
 
 	ecryptfs_set_dentry_private(dentry, dentry_info);
···
 	if (d_really_is_negative(lower_dentry)) {
 		/* We want to add because we couldn't find in lower */
 		d_add(dentry, NULL);
-		return 0;
+		return NULL;
 	}
-	inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
+	inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
 	if (IS_ERR(inode)) {
 		printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
 		       __func__, PTR_ERR(inode));
-		return PTR_ERR(inode);
+		return ERR_CAST(inode);
 	}
 	if (S_ISREG(inode->i_mode)) {
 		rc = ecryptfs_i_size_read(dentry, inode);
 		if (rc) {
 			make_bad_inode(inode);
-			return rc;
+			return ERR_PTR(rc);
 		}
 	}
 
 	if (inode->i_state & I_NEW)
 		unlock_new_inode(inode);
-	d_add(dentry, inode);
-
-	return rc;
+	return d_splice_alias(inode, dentry);
 }
 
 /**
···
 				      unsigned int flags)
 {
 	char *encrypted_and_encoded_name = NULL;
-	size_t encrypted_and_encoded_name_size;
-	struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	struct dentry *lower_dir_dentry, *lower_dentry;
+	const char *name = ecryptfs_dentry->d_name.name;
+	size_t len = ecryptfs_dentry->d_name.len;
+	struct dentry *res;
 	int rc = 0;
 
 	lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
-	lower_dentry = lookup_one_len_unlocked(ecryptfs_dentry->d_name.name,
-				      lower_dir_dentry,
-				      ecryptfs_dentry->d_name.len);
-	if (IS_ERR(lower_dentry)) {
-		rc = PTR_ERR(lower_dentry);
-		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
-				"[%d] on lower_dentry = [%pd]\n", __func__, rc,
-				ecryptfs_dentry);
-		goto out;
-	}
-	if (d_really_is_positive(lower_dentry))
-		goto interpose;
+
 	mount_crypt_stat = &ecryptfs_superblock_to_private(
 				ecryptfs_dentry->d_sb)->mount_crypt_stat;
-	if (!(mount_crypt_stat
-	    && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
-		goto interpose;
-	dput(lower_dentry);
-	rc = ecryptfs_encrypt_and_encode_filename(
-		&encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
-		mount_crypt_stat, ecryptfs_dentry->d_name.name,
-		ecryptfs_dentry->d_name.len);
-	if (rc) {
-		printk(KERN_ERR "%s: Error attempting to encrypt and encode "
-		       "filename; rc = [%d]\n", __func__, rc);
-		goto out;
+	if (mount_crypt_stat
+	    && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) {
+		rc = ecryptfs_encrypt_and_encode_filename(
+			&encrypted_and_encoded_name, &len,
+			mount_crypt_stat, name, len);
+		if (rc) {
+			printk(KERN_ERR "%s: Error attempting to encrypt and encode "
+			       "filename; rc = [%d]\n", __func__, rc);
+			return ERR_PTR(rc);
+		}
+		name = encrypted_and_encoded_name;
 	}
-	lower_dentry = lookup_one_len_unlocked(encrypted_and_encoded_name,
-				      lower_dir_dentry,
-				      encrypted_and_encoded_name_size);
+
+	lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
 	if (IS_ERR(lower_dentry)) {
-		rc = PTR_ERR(lower_dentry);
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
-				"[%d] on lower_dentry = [%s]\n", __func__, rc,
-				encrypted_and_encoded_name);
-		goto out;
+				"[%ld] on lower_dentry = [%s]\n", __func__,
+				PTR_ERR(lower_dentry),
+				name);
+		res = ERR_CAST(lower_dentry);
+	} else {
+		res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
 	}
-interpose:
-	rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
-				       ecryptfs_dir_inode);
-out:
 	kfree(encrypted_and_encoded_name);
-	return ERR_PTR(rc);
+	return res;
 }
 
 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,

kernel/bpf/inode.c

···
 	return 0;
 }
 
-static bool bpf_dname_reserved(const struct dentry *dentry)
-{
-	return strchr(dentry->d_name.name, '.');
-}
-
 static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
-
-	if (bpf_dname_reserved(dentry))
-		return -EPERM;
 
 	inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFDIR);
 	if (IS_ERR(inode))
···
 			 umode_t mode, const struct inode_operations *iops)
 {
 	struct inode *inode;
-
-	if (bpf_dname_reserved(dentry))
-		return -EPERM;
 
 	inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFREG);
 	if (IS_ERR(inode))
···
 	}
 }
 
-static int bpf_link(struct dentry *old_dentry, struct inode *dir,
-		    struct dentry *new_dentry)
+static struct dentry *
+bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
 {
-	if (bpf_dname_reserved(new_dentry))
-		return -EPERM;
-
-	return simple_link(old_dentry, dir, new_dentry);
-}
-
-static int bpf_rename(struct inode *old_dir, struct dentry *old_dentry,
-		      struct inode *new_dir, struct dentry *new_dentry)
-{
-	if (bpf_dname_reserved(new_dentry))
-		return -EPERM;
-
-	return simple_rename(old_dir, old_dentry, new_dir, new_dentry);
+	if (strchr(dentry->d_name.name, '.'))
+		return ERR_PTR(-EPERM);
+	return simple_lookup(dir, dentry, flags);
 }
 
 static const struct inode_operations bpf_dir_iops = {
-	.lookup		= simple_lookup,
+	.lookup		= bpf_lookup,
 	.mknod		= bpf_mkobj,
 	.mkdir		= bpf_mkdir,
 	.rmdir		= simple_rmdir,
-	.rename		= bpf_rename,
-	.link		= bpf_link,
+	.rename		= simple_rename,
+	.link		= simple_link,
 	.unlink		= simple_unlink,
 };