ext4: Remove CONFIG_EXT4_FS_XATTR

Ted has sent out a RFC about removing this feature. Eric and Jan
confirmed that both RedHat and SUSE enable this feature in all their
product. David also said that "As far as I know, it's enabled in all
Android kernels that use ext4." So it seems OK for us.

And what's more, as inline data depends its implementation on xattr,
and to be frank, I don't run any test again inline data enabled while
xattr disabled. So I think we should add inline data and remove this
config option in the same release.

[ The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which
isn't much in the grand scheme of things. Since no one seems to be
testing this configuration except for some automated compile farms, on
balance we are better removing this config option, and so that it is
effectively always enabled. -- tytso ]

Cc: David Brown <[e-mail]>
Cc: Eric Sandeen <[e-mail]>
Reviewed-by: Jan Kara <[e-mail]>
Signed-off-by: Tao Ma <[e-mail]>
Signed-off-by: "Theodore Ts'o" <[e-mail]>

Documentation/filesystems/ext4.txt

···
 			table readahead algorithm will pre-read into
 			the buffer cache.  The default value is 32 blocks.
 
-nouser_xattr		Disables Extended User Attributes. If you have extended
-			attribute support enabled in the kernel configuration
-			(CONFIG_EXT4_FS_XATTR), extended attribute support
-			is enabled by default on mount. See the attr(5) manual
-			page and http://acl.bestbits.at/ for more information
-			about extended attributes.
+nouser_xattr		Disables Extended User Attributes.  See the
+			attr(5) manual page and http://acl.bestbits.at/
+			for more information about extended attributes.
 
 noacl			This option disables POSIX Access Control List
 			support. If ACL support is enabled in the kernel

fs/Kconfig

···
 	tristate
 	default y if EXT2_FS=y && EXT2_FS_XATTR
 	default y if EXT3_FS=y && EXT3_FS_XATTR
-	default y if EXT4_FS=y && EXT4_FS_XATTR
-	default m if EXT2_FS_XATTR || EXT3_FS_XATTR || EXT4_FS_XATTR
+	default y if EXT4_FS=y
+	default m if EXT2_FS_XATTR || EXT3_FS_XATTR || EXT4_FS
 
 source "fs/reiserfs/Kconfig"
 source "fs/jfs/Kconfig"

fs/ext4/Kconfig

···
 	  compiled kernel size by using one file system driver for
 	  ext2, ext3, and ext4 file systems.
 
-config EXT4_FS_XATTR
-	bool "Ext4 extended attributes"
-	depends on EXT4_FS
-	default y
-	help
-	  Extended attributes are name:value pairs associated with inodes by
-	  the kernel or by users (see the attr(5) manual page, or visit
-	  <http://acl.bestbits.at/> for details).
-
-	  If unsure, say N.
-
-	  You need this for POSIX ACL support on ext4.
-
 config EXT4_FS_POSIX_ACL
 	bool "Ext4 POSIX Access Control Lists"
-	depends on EXT4_FS_XATTR
 	select FS_POSIX_ACL
 	help
 	  POSIX Access Control Lists (ACLs) support permissions for users and
···
 
 config EXT4_FS_SECURITY
 	bool "Ext4 Security Labels"
-	depends on EXT4_FS_XATTR
 	help
 	  Security labels support alternative access control models
 	  implemented by security modules like SELinux.  This option

fs/ext4/Makefile

···
 ext4-y	:= balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o page-io.o \
 		ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \
 		ext4_jbd2.o migrate.o mballoc.o block_validity.o move_extent.o \
-		mmp.o indirect.o extents_status.o
+		mmp.o indirect.o extents_status.o xattr.o xattr_user.o \
+		xattr_trusted.o inline.o
 
-ext4-$(CONFIG_EXT4_FS_XATTR)		+= xattr.o xattr_user.o xattr_trusted.o inline.o
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o

fs/ext4/ext4.h

···
 #endif
 	unsigned long	i_flags;
 
-#ifdef CONFIG_EXT4_FS_XATTR
 	/*
 	 * Extended attributes can be read independently of the main file
 	 * data. Taking i_mutex even when reading would cause contention
···
 	 * EAs.
 	 */
 	struct rw_semaphore xattr_sem;
-#endif
 
 	struct list_head i_orphan;	/* unlinked but open inodes */
 

fs/ext4/file.c

···
 const struct inode_operations ext4_file_inode_operations = {
 	.setattr	= ext4_setattr,
 	.getattr	= ext4_getattr,
-#ifdef CONFIG_EXT4_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
-#endif
 	.get_acl	= ext4_get_acl,
 	.fiemap		= ext4_fiemap,
 };

fs/ext4/namei.c

···
 	.mknod		= ext4_mknod,
 	.rename		= ext4_rename,
 	.setattr	= ext4_setattr,
-#ifdef CONFIG_EXT4_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
-#endif
 	.get_acl	= ext4_get_acl,
 	.fiemap         = ext4_fiemap,
 };
 
 const struct inode_operations ext4_special_inode_operations = {
 	.setattr	= ext4_setattr,
-#ifdef CONFIG_EXT4_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
-#endif
 	.get_acl	= ext4_get_acl,
 };

fs/ext4/super.c

···
 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 
 	INIT_LIST_HEAD(&ei->i_orphan);
-#ifdef CONFIG_EXT4_FS_XATTR
 	init_rwsem(&ei->xattr_sem);
-#endif
 	init_rwsem(&ei->i_data_sem);
 	inode_init_once(&ei->vfs_inode);
 }
···
 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
-#ifdef CONFIG_EXT4_FS_XATTR
 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
-#else
-	{Opt_user_xattr, 0, MOPT_NOSUPPORT},
-	{Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
-#endif
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
···
 	if (def_mount_opts & EXT4_DEFM_UID16)
 		set_opt(sb, NO_UID32);
 	/* xattr user namespace & acls are now defaulted on */
-#ifdef CONFIG_EXT4_FS_XATTR
 	set_opt(sb, XATTR_USER);
-#endif
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 	set_opt(sb, POSIX_ACL);
 #endif

fs/ext4/symlink.c

···
 	.follow_link	= page_follow_link_light,
 	.put_link	= page_put_link,
 	.setattr	= ext4_setattr,
-#ifdef CONFIG_EXT4_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
-#endif
 };
 
 const struct inode_operations ext4_fast_symlink_inode_operations = {
 	.readlink	= generic_readlink,
 	.follow_link	= ext4_follow_link,
 	.setattr	= ext4_setattr,
-#ifdef CONFIG_EXT4_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
-#endif
 };

fs/ext4/xattr.h

···
 	struct ext4_iloc iloc;
 };
 
-# ifdef CONFIG_EXT4_FS_XATTR
-
 extern const struct xattr_handler ext4_xattr_user_handler;
 extern const struct xattr_handler ext4_xattr_trusted_handler;
 extern const struct xattr_handler ext4_xattr_acl_access_handler;
···
 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
 
 extern int ext4_convert_inline_data(struct inode *inode);
-# else  /* CONFIG_EXT4_FS_XATTR */
-
-static inline int
-ext4_xattr_get(struct inode *inode, int name_index, const char *name,
-	       void *buffer, size_t size, int flags)
-{
-	return -EOPNOTSUPP;
-}
-
-static inline int
-ext4_xattr_set(struct inode *inode, int name_index, const char *name,
-	       const void *value, size_t size, int flags)
-{
-	return -EOPNOTSUPP;
-}
-
-static inline int
-ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
-	       const char *name, const void *value, size_t size, int flags)
-{
-	return -EOPNOTSUPP;
-}
-
-static inline void
-ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
-{
-}
-
-static inline void
-ext4_xattr_put_super(struct super_block *sb)
-{
-}
-
-static __init inline int
-ext4_init_xattr(void)
-{
-	return 0;
-}
-
-static inline void
-ext4_exit_xattr(void)
-{
-}
-
-static inline int
-ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
-			    struct ext4_inode *raw_inode, handle_t *handle)
-{
-	return -EOPNOTSUPP;
-}
-
-#define ext4_xattr_handlers	NULL
-
-static inline int
-ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
-		      struct ext4_xattr_ibody_find *is)
-{
-	return -EOPNOTSUPP;
-}
-
-static inline int
-ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
-		     struct ext4_xattr_info *i,
-		     struct ext4_xattr_ibody_find *is)
-{
-	return -EOPNOTSUPP;
-}
-
-static inline int
-ext4_xattr_ibody_get(struct inode *inode, int name_index,
-		     const char *name,
-		     void *buffer, size_t buffer_size)
-{
-	return -EOPNOTSUPP;
-}
-
-static inline int ext4_find_inline_data_nolock(struct inode *inode)
-{
-	return 0;
-}
-
-static inline int ext4_has_inline_data(struct inode *inode)
-{
-	return 0;
-}
-
-static inline int ext4_get_inline_size(struct inode *inode)
-{
-	return 0;
-}
-
-static inline int ext4_get_max_inline_size(struct inode *inode)
-{
-	return 0;
-}
-
-static inline void ext4_write_inline_data(struct inode *inode,
-					  struct ext4_iloc *iloc,
-					  void *buffer, loff_t pos,
-					  unsigned int len)
-{
-	return;
-}
-
-static inline int ext4_init_inline_data(handle_t *handle,
-					struct inode *inode,
-					unsigned int len)
-{
-	return 0;
-}
-
-static inline int ext4_destroy_inline_data(handle_t *handle,
-					   struct inode *inode)
-{
-	return 0;
-}
-
-static inline int ext4_readpage_inline(struct inode *inode, struct page *page)
-{
-	return 0;
-}
-
-static inline int ext4_try_to_write_inline_data(struct address_space *mapping,
-						struct inode *inode,
-						loff_t pos, unsigned len,
-						unsigned flags,
-						struct page **pagep)
-{
-	return 0;
-}
-
-static inline int ext4_write_inline_data_end(struct inode *inode,
-					     loff_t pos, unsigned len,
-					     unsigned copied,
-					     struct page *page)
-{
-	return 0;
-}
-
-static inline struct buffer_head *
-ext4_journalled_write_inline_data(struct inode *inode,
-				  unsigned len,
-				  struct page *page)
-{
-	return NULL;
-}
-
-static inline int
-ext4_da_write_inline_data_begin(struct address_space *mapping,
-				struct inode *inode,
-				loff_t pos, unsigned len,
-				unsigned flags,
-				struct page **pagep,
-				void **fsdata)
-{
-	return 0;
-}
-
-static inline int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
-						unsigned len, unsigned copied,
-						struct page *page)
-{
-	return 0;
-}
-
-static inline int ext4_try_add_inline_entry(handle_t *handle,
-					    struct dentry *dentry,
-					    struct inode *inode)
-{
-	return 0;
-}
-
-static inline int ext4_try_create_inline_dir(handle_t *handle,
-					     struct inode *parent,
-					     struct inode *inode)
-{
-	return 0;
-}
-static inline int ext4_read_inline_dir(struct file *filp,
-				       void *dirent, filldir_t filldir,
-				       int *has_inline_data)
-{
-	return 0;
-}
-
-static inline struct buffer_head *
-ext4_find_inline_entry(struct inode *dir,
-		       const struct qstr *d_name,
-		       struct ext4_dir_entry_2 **res_dir,
-		       int *has_inline_data)
-{
-	return NULL;
-}
-static inline int ext4_delete_inline_entry(handle_t *handle,
-					   struct inode *dir,
-					   struct ext4_dir_entry_2 *de_del,
-					   struct buffer_head *bh,
-					   int *has_inline_data)
-{
-	return 0;
-}
-
-static inline int empty_inline_dir(struct inode *dir, int *has_inline_data)
-{
-	return 0;
-}
-
-static inline struct buffer_head *
-ext4_get_first_inline_block(struct inode *inode,
-			    struct ext4_dir_entry_2 **parent_de,
-			    int *retval)
-{
-	return NULL;
-}
-
-static inline int ext4_inline_data_fiemap(struct inode *inode,
-					  struct fiemap_extent_info *fieinfo,
-					  int *has_inline)
-{
-	return 0;
-}
-
-static inline void ext4_inline_data_truncate(struct inode *inode,
-					     int *has_inline)
-{
-	return;
-}
-
-static inline int ext4_convert_inline_data(struct inode *inode)
-{
-	return 0;
-}
-# endif  /* CONFIG_EXT4_FS_XATTR */
 
 #ifdef CONFIG_EXT4_FS_SECURITY
 extern int ext4_init_security(handle_t *handle, struct inode *inode,