ext4: serialize dio nonlocked reads with defrag workers
Inode's block defrag and ext4_change_inode_journal_flag() may
affect nonlocked DIO reads result, so proper synchronization
required.
- Add missed inode_dio_wait() calls where appropriate
- Check inode state under extra i_dio_count reference.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 8076b96..292daee 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -1323,6 +1323,12 @@
/* Protect orig and donor inodes against a truncate */
mext_inode_double_lock(orig_inode, donor_inode);
+ /* Wait for all existing dio workers */
+ ext4_inode_block_unlocked_dio(orig_inode);
+ ext4_inode_block_unlocked_dio(donor_inode);
+ inode_dio_wait(orig_inode);
+ inode_dio_wait(donor_inode);
+
/* Protect extent tree against block allocations via delalloc */
double_down_write_data_sem(orig_inode, donor_inode);
/* Check the filesystem environment whether move_extent can be done */
@@ -1521,6 +1527,8 @@
kfree(holecheck_path);
}
double_up_write_data_sem(orig_inode, donor_inode);
+ ext4_inode_resume_unlocked_dio(orig_inode);
+ ext4_inode_resume_unlocked_dio(donor_inode);
mext_inode_double_unlock(orig_inode, donor_inode);
return ret;