Amit K. Arora wrote:

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FA_FL_NO_MTIME	0x10 /* keep same mtime (default change on size, data change) */
FA_FL_NO_CTIME	0x20 /* keep same ctime (default change on size, data change) */

NACK to these aswell.  If i_size changes c/mtime need updates, if the size
doesn't chamge they don't.  No need to add more flags for this.

This requirement was from the point of view of HSM applications. Hope
you saw Andreas previous post and are keeping that in mind.

We use this capability in XFS at the moment.
I think this is mainly for DMF (HSM) but is done via the xfs handle interface
(xfs_open_by_handle) AFAICT.

This sets up a set of invisible operations (xfs_invis_file_operations).
xfs_file_ioctl_invis goes on to set IO_INVIS which goes on to set ATTR_DMI
which is then tested in xfs_change_file_space() (which handles XFS_IOC_RESVSP & friends)
for whether xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG)
is called or not.

--Tim