In the case of remounting (using the mount -u option), there is a somewhat unexpected behavior that occurs with regards to the handling of flags like 'noatime' that get passed to the io-blk layer. It is in fact possible to pass flags to the io-blk layer when issuing the mount command, and this can be done with the -o option.
For example if you were to pass the "blk noatime' setting to the io-blk layer when starting your block device driver, and then subsequently remounted the filesystem on the device using "mount -u", the 'noatime' flag that was previously set would be unset. Future accesses to the filesystem would result in the access time being updated.
This and some other options can be turned on by using the -o option to the mount command. For example:
# mount -u -o noatime /dev/hd0t79 /home
It turns out that there are only a subset of possible io-blk options that can be affected by the re-mount. These can be seen by referencing the following header file on a 640 windows installation:
NOTE:
This entry has been validated against the SDP version listed above. Use
caution when considering this advice for any other SDP version. For
supported releases, please reach out toQNX Technical Support if you have any questions/concerns.
