Yes, ext4 uses inode mutexes by default like ext3. They're needed if you want to use a journal, for example. Open http://www.kernel.org/doc/Documentation/filesy

Yes, ext4 uses inode mutexes by default like ext3. They're needed if you want to use a journal, for example. Open http://www.kernel.org/doc/Documentation/filesystems/ext4.txt http://www.kernel.org/doc/Documentation/filesystems/ext4.txt and look for dioread_lock for more information.