ntfs: ->d_compare() must not block

... so don't use __getname() there. Switch it (and ntfs_d_hash(), while
we are at it) to kmalloc(PATH_MAX, GFP_NOWAIT). Yes, ntfs_d_hash()
almost certainly can do with smaller allocations, but let ntfs folks
deal with that - keep the allocation size as-is for now.

Stop abusing names_cachep in ntfs, period - various uses of that thing
in there have nothing to do with pathnames; just use k[mz]alloc() and
be done with that. For now let's keep sizes as-in, but AFAICS none of
the users actually want PATH_MAX.

Signed-off-by: Al Viro <[e-mail]>

fs/ntfs3/dir.c

···
 	if (!dir_emit_dots(file, ctx))
 		return 0;
 
-	/* Allocate PATH_MAX bytes. */
-	name = __getname();
+	name = kmalloc(PATH_MAX, GFP_KERNEL);
 	if (!name)
 		return -ENOMEM;
 
···
 
 out:
 
-	__putname(name);
+	kfree(name);
 	put_indx_node(node);
 
 	if (err == 1) {

fs/ntfs3/fsntfs.c

···
 	u32 uni_bytes;
 	struct ntfs_inode *ni = sbi->volume.ni;
 	/* Allocate PATH_MAX bytes. */
-	struct cpu_str *uni = __getname();
+	struct cpu_str *uni = kmalloc(PATH_MAX, GFP_KERNEL);
 
 	if (!uni)
 		return -ENOMEM;
···
 		err = _ni_write_inode(&ni->vfs_inode, 0);
 
 out:
-	__putname(uni);
+	kfree(uni);
 	return err;
 }

fs/ntfs3/inode.c

···
 		fa |= FILE_ATTRIBUTE_READONLY;
 
 	/* Allocate PATH_MAX bytes. */
-	new_de = kmem_cache_zalloc(names_cachep, GFP_KERNEL);
+	new_de = kzalloc(PATH_MAX, GFP_KERNEL);
 	if (!new_de) {
 		err = -ENOMEM;
 		goto out1;
···
 	ntfs_mark_rec_free(sbi, ino, false);
 
 out2:
-	__putname(new_de);
+	kfree(new_de);
 	kfree(rp);
 
 out1:
···
 	struct NTFS_DE *de;
 
 	/* Allocate PATH_MAX bytes. */
-	de = kmem_cache_zalloc(names_cachep, GFP_KERNEL);
+	de = kzalloc(PATH_MAX, GFP_KERNEL);
 	if (!de)
 		return -ENOMEM;
 
···
 
 	err = ni_add_name(ntfs_i(d_inode(dentry->d_parent)), ni, de);
 out:
-	__putname(de);
+	kfree(de);
 	return err;
 }
 
···
 	if (ntfs_is_meta_file(sbi, ni->mi.rno))
 		return -EINVAL;
 
-	/* Allocate PATH_MAX bytes. */
-	de = kmem_cache_zalloc(names_cachep, GFP_KERNEL);
+	de = kzalloc(PATH_MAX, GFP_KERNEL);
 	if (!de)
 		return -ENOMEM;
 
···
 
 out:
 	ni_unlock(ni);
-	__putname(de);
+	kfree(de);
 	return err;
 }
 

fs/ntfs3/namei.c

···
 				  u32 flags)
 {
 	struct ntfs_inode *ni = ntfs_i(dir);
-	struct cpu_str *uni = __getname();
+	struct cpu_str *uni = kmalloc(PATH_MAX, GFP_KERNEL);
 	struct inode *inode;
 	int err;
 
···
 			inode = dir_search_u(dir, uni, NULL);
 			ni_unlock(ni);
 		}
-		__putname(uni);
+		kfree(uni);
 	}
 
 	/*
···
 			return err;
 	}
 
-	/* Allocate PATH_MAX bytes. */
-	de = __getname();
+	de = kmalloc(PATH_MAX, GFP_KERNEL);
 	if (!de)
 		return -ENOMEM;
 
···
 	ni_unlock(ni);
 	ni_unlock(dir_ni);
 out:
-	__putname(de);
+	kfree(de);
 	return err;
 }
 
···
 	/*
 	 * Try slow way with current upcase table
 	 */
-	uni = kmem_cache_alloc(names_cachep, GFP_NOWAIT);
+	uni = kmalloc(PATH_MAX, GFP_NOWAIT);
 	if (!uni)
 		return -ENOMEM;
 
···
 	err = 0;
 
 out:
-	kmem_cache_free(names_cachep, uni);
+	kfree(uni);
 	return err;
 }
 
···
 	 * Try slow way with current upcase table
 	 */
 	sbi = dentry->d_sb->s_fs_info;
-	uni1 = __getname();
+	uni1 = kmalloc(PATH_MAX, GFP_NOWAIT);
 	if (!uni1)
 		return -ENOMEM;
 
···
 	ret = !ntfs_cmp_names_cpu(uni1, uni2, sbi->upcase, false) ? 0 : 1;
 
 out:
-	__putname(uni1);
+	kfree(uni1);
 	return ret;
 }
 

fs/ntfs3/xattr.c

···
 	if (unlikely(is_bad_ni(ni)))
 		return ERR_PTR(-EINVAL);
 
-	/* Allocate PATH_MAX bytes. */
-	buf = __getname();
+	buf = kmalloc(PATH_MAX, GFP_KERNEL);
 	if (!buf)
 		return ERR_PTR(-ENOMEM);
 
···
 	if (!IS_ERR(acl))
 		set_cached_acl(inode, type, acl);
 
-	__putname(buf);
+	kfree(buf);
 
 	return acl;
 }