ext4: dynamically allocate the jbd2_inode in ext4_inode_info as necessary
Replace the jbd2_inode structure (which is 48 bytes) with a pointer
and only allocate the jbd2_inode when it is needed --- that is, when
the file system has a journal present and the inode has been opened
for writing. This allows us to further slim down the ext4_inode_info
structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f5960d6..1cd4326 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -818,12 +818,6 @@
memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
INIT_LIST_HEAD(&ei->i_prealloc_list);
spin_lock_init(&ei->i_prealloc_lock);
- /*
- * Note: We can be called before EXT4_SB(sb)->s_journal is set,
- * therefore it can be null here. Don't check it, just initialize
- * jinode.
- */
- jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
ei->i_reserved_data_blocks = 0;
ei->i_reserved_meta_blocks = 0;
ei->i_allocated_meta_blocks = 0;
@@ -832,6 +826,7 @@
#ifdef CONFIG_QUOTA
ei->i_reserved_quota = 0;
#endif
+ ei->jinode = NULL;
INIT_LIST_HEAD(&ei->i_completed_io_list);
spin_lock_init(&ei->i_completed_io_lock);
ei->cur_aio_dio = NULL;
@@ -900,9 +895,12 @@
end_writeback(inode);
dquot_drop(inode);
ext4_discard_preallocations(inode);
- if (EXT4_JOURNAL(inode))
- jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
- &EXT4_I(inode)->jinode);
+ if (EXT4_I(inode)->jinode) {
+ jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
+ EXT4_I(inode)->jinode);
+ jbd2_free_inode(EXT4_I(inode)->jinode);
+ EXT4_I(inode)->jinode = NULL;
+ }
}
static inline void ext4_show_quota_options(struct seq_file *seq,