ext4: move ext4_update_i_disksize() into mpage_map_and_submit_extent()
authorTheodore Ts'o <tytso@mit.edu>
Fri, 11 Apr 2014 14:35:17 +0000 (10:35 -0400)
committerTheodore Ts'o <tytso@mit.edu>
Fri, 11 Apr 2014 14:35:17 +0000 (10:35 -0400)
commit622cad1325e404598fe3b148c3fa640dbaabc235
tree45f8f60ba6246b9f7276146635c15fb44195f763
parentc57ab39b9658315a742b6e61fdc86bb4d20cf566
ext4: move ext4_update_i_disksize() into mpage_map_and_submit_extent()

The function ext4_update_i_disksize() is used in only one place, in
the function mpage_map_and_submit_extent().  Move its code to simplify
the code paths, and also move the call to ext4_mark_inode_dirty() into
the i_data_sem's critical region, to be consistent with all of the
other places where we update i_disksize.  That way, we also keep the
raw_inode's i_disksize protected, to avoid the following race:

      CPU #1                                 CPU #2

   down_write(&i_data_sem)
   Modify i_disk_size
   up_write(&i_data_sem)
                                        down_write(&i_data_sem)
                                        Modify i_disk_size
                                        Copy i_disk_size to on-disk inode
                                        up_write(&i_data_sem)
   Copy i_disk_size to on-disk inode

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
fs/ext4/ext4.h
fs/ext4/inode.c