ext4: fix the number of credits needed for acl ops with inline data

Operations which modify extended attributes may need extra journal
credits if inline data is used, since there is a chance that some
extended attributes may need to get pushed to an external attribute
block.

Changes to reflect this was made in xattr.c, but they were missed in
fs/ext4/acl.c.  To fix this, abstract the calculation of the number of
credits needed for xattr operations to an inline function defined in
ext4_jbd2.h, and use it in acl.c and xattr.c.

Also move the function declarations used in inline.c from xattr.h
(where they are non-obviously hidden, and caused problems since
ext4_jbd2.h needs to use the function ext4_has_inline_data), and move
them to ext4.h.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Tao Ma <boyu.mt@taobao.com>
Reviewed-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 406cf8b..39a54a0 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -325,7 +325,7 @@
 		return error;
 retry:
 	handle = ext4_journal_start(inode, EXT4_HT_XATTR,
-			EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
+				    ext4_jbd2_credits_xattr(inode));
 	if (IS_ERR(handle)) {
 		error = PTR_ERR(handle);
 		ext4_std_error(inode->i_sb, error);
@@ -423,7 +423,7 @@
 
 retry:
 	handle = ext4_journal_start(inode, EXT4_HT_XATTR,
-				    EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
+				    ext4_jbd2_credits_xattr(inode));
 	if (IS_ERR(handle)) {
 		error = PTR_ERR(handle);
 		goto release_and_out;