Add the callbacks as opt-in to override the default behavior for the transaction's inode list, instead of moving that code around. This is important as not only ext4 uses the inode list: ocfs2 too, via jbd2_journal_inode_ranged_write(), and maybe out-of-tree code. To opt-out of the default behavior (i.e., to do nothing), one has to opt-in with a no-op function. --- fs/jbd2/commit.c | 21 ++++++++++++++++----- include/linux/jbd2.h | 21 ++++++++++++++++++++- 2 files changed, 36 insertions(+), 6 deletions(-) diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 51f713089e35..b98d227b50d8 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -237,10 +237,14 @@ static int journal_submit_data_buffers(journal_t *journal, * instead of writepages. Because writepages can do * block allocation with delalloc. We need to write * only allocated blocks here. + * This can be overriden with a custom callback. */ trace_jbd2_submit_inode_data(jinode->i_vfs_inode); - err = journal_submit_inode_data_buffers(mapping, dirty_start, - dirty_end); + if (journal->j_submit_inode_data_buffers) + err = journal->j_submit_inode_data_buffers(jinode); + else + err = journal_submit_inode_data_buffers(mapping, + dirty_start, dirty_end); if (!ret) ret = err; spin_lock(&journal->j_list_lock); @@ -274,9 +278,16 @@ static int journal_finish_inode_data_buffers(journal_t *journal, continue; jinode->i_flags |= JI_COMMIT_RUNNING; spin_unlock(&journal->j_list_lock); - err = filemap_fdatawait_range_keep_errors( - jinode->i_vfs_inode->i_mapping, dirty_start, - dirty_end); + /* + * Wait for the inode data buffers writeout. + * This can be overriden with a custom callback. + */ + if (journal->j_finish_inode_data_buffers) + err = journal->j_finish_inode_data_buffers(jinode); + else + err = filemap_fdatawait_range_keep_errors( + jinode->i_vfs_inode->i_mapping, + dirty_start, dirty_end); if (!ret) ret = err; spin_lock(&journal->j_list_lock); diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index d56128df2aff..24efe88eda1b 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -628,7 +628,8 @@ struct transaction_s struct journal_head *t_shadow_list; /* - * List of inodes whose data we've modified in data=ordered mode. + * List of inodes whose data we've modified in data=ordered mode + * or whose pages we should write-protect in data=journaled mode. * [j_list_lock] */ struct list_head t_inode_list; @@ -1110,6 +1111,24 @@ struct journal_s void (*j_commit_callback)(journal_t *, transaction_t *); + /** + * @j_submit_inode_data_buffers: + * + * This function is called before flushing metadata buffers. + * This overrides the default behavior (writeout data buffers.) + */ + int (*j_submit_inode_data_buffers) + (struct jbd2_inode *); + + /** + * @j_finish_inode_data_buffers: + * + * This function is called after flushing metadata buffers. + * This overrides the default behavior (wait writeout.) + */ + int (*j_finish_inode_data_buffers) + (struct jbd2_inode *); + /* * Journal statistics */ -- 2.17.1
