btrfs: Switch to generic xattr handlers

The btrfs_{set,remove}xattr inode operations check for a read-only root
(btrfs_root_readonly) before calling into generic_{set,remove}xattr.  If
this check is moved into __btrfs_setxattr, we can get rid of
btrfs_{set,remove}xattr.

This patch applies to mainline, I would like to keep it together with
the other xattr cleanups if possible, though.  Could you please review?

Thanks,
Andreas
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/btrfs/inode.c

@@ -10160,10 +10160,10 @@ static const struct inode_operations btrfs_dir_inode_operations = {
 	.symlink	= btrfs_symlink,
 	.setattr	= btrfs_setattr,
 	.mknod		= btrfs_mknod,
-	.setxattr	= btrfs_setxattr,
+	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= btrfs_listxattr,
-	.removexattr	= btrfs_removexattr,
+	.removexattr	= generic_removexattr,
 	.permission	= btrfs_permission,
 	.get_acl	= btrfs_get_acl,
 	.set_acl	= btrfs_set_acl,
@@ -10237,10 +10237,10 @@ static const struct address_space_operations btrfs_symlink_aops = {
 static const struct inode_operations btrfs_file_inode_operations = {
 	.getattr	= btrfs_getattr,
 	.setattr	= btrfs_setattr,
-	.setxattr	= btrfs_setxattr,
+	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr      = btrfs_listxattr,
-	.removexattr	= btrfs_removexattr,
+	.removexattr	= generic_removexattr,
 	.permission	= btrfs_permission,
 	.fiemap		= btrfs_fiemap,
 	.get_acl	= btrfs_get_acl,
@@ -10251,10 +10251,10 @@ static const struct inode_operations btrfs_special_inode_operations = {
 	.getattr	= btrfs_getattr,
 	.setattr	= btrfs_setattr,
 	.permission	= btrfs_permission,
-	.setxattr	= btrfs_setxattr,
+	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= btrfs_listxattr,
-	.removexattr	= btrfs_removexattr,
+	.removexattr	= generic_removexattr,
 	.get_acl	= btrfs_get_acl,
 	.set_acl	= btrfs_set_acl,
 	.update_time	= btrfs_update_time,
@@ -10265,10 +10265,10 @@ static const struct inode_operations btrfs_symlink_inode_operations = {
 	.getattr	= btrfs_getattr,
 	.setattr	= btrfs_setattr,
 	.permission	= btrfs_permission,
-	.setxattr	= btrfs_setxattr,
+	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= btrfs_listxattr,
-	.removexattr	= btrfs_removexattr,
+	.removexattr	= generic_removexattr,
 	.update_time	= btrfs_update_time,
 };
 

fs/btrfs/xattr.c

@@ -237,6 +237,9 @@ int __btrfs_setxattr(struct btrfs_trans_handle *trans,
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	int ret;
 
+	if (btrfs_root_readonly(root))
+		return -EROFS;
+
 	if (trans)
 		return do_setxattr(trans, inode, name, value, size, flags);
 
@@ -432,25 +435,6 @@ const struct xattr_handler *btrfs_xattr_handlers[] = {
 	NULL,
 };
 
-int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
-		   size_t size, int flags)
-{
-	struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root;
-
-	if (btrfs_root_readonly(root))
-		return -EROFS;
-	return generic_setxattr(dentry, name, value, size, flags);
-}
-
-int btrfs_removexattr(struct dentry *dentry, const char *name)
-{
-	struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root;
-
-	if (btrfs_root_readonly(root))
-		return -EROFS;
-	return generic_removexattr(dentry, name);
-}
-
 static int btrfs_initxattrs(struct inode *inode,
 			    const struct xattr *xattr_array, void *fs_info)
 {

fs/btrfs/xattr.h

@@ -28,9 +28,6 @@ extern ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
 extern int __btrfs_setxattr(struct btrfs_trans_handle *trans,
 			    struct inode *inode, const char *name,
 			    const void *value, size_t size, int flags);
-extern int btrfs_setxattr(struct dentry *dentry, const char *name,
-		const void *value, size_t size, int flags);
-extern int btrfs_removexattr(struct dentry *dentry, const char *name);
 
 extern int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
 				     struct inode *inode, struct inode *dir,