The option delay_mtime avoid updating the mtime of a file after each
individual updating. With this patch, the frequency of the update can
be adjusted to needs (default 60s). This is mainly useful for big files
which are kept open for a long period (file system images, virtual
computers, etc.)
This patch avoid updating the time stamps whenever a file is modified,
by delaying the time stamps updating until the file is closed.
This is mostly useful when the ntfs file system hosts another loop-monted
file system to avoid frequent updates of the time stamps in the outer
file system.
For some reason, when the monted device is "/dev/mapper/*", a record
in the form "/dev/dm-*" ends up in /etc/mtab and the device cannot be
unmounted.
The reason is unclear, the /dev/mapper name is not a symlink, and the
function doing the name change is not known. No detailed feedback from
the users having met the issue.
The patch changes the name back to the /dev/mapper name after realpath()
is called, and, if there is an actual change, both the name passed to
ntfs-3g and the one passed to fuse and mount are logged in the hope
of getting a clue about what is happening.
But ntfs-3g is probably not the right place for a fix.