On Thu, Feb 08, 2018 at 10:57:19AM -0500, Brian Foster wrote: > Extent swap is a low level mechanism exported by XFS to facilitate > filesystem defragmentation. It is typically invoked by xfs_fsr under > conditions that will atomically adjust inode extent state without > loss of file data. > > While xfs_fsr provides some debug capability to tailor its behavior, > it is not flexible enough to facilitate low level tests of the > extent swap mechanism. For example, xfs_fsr may skip swaps between > inodes that consist solely of preallocated extents because it > considers such files already 100% defragmented. Further, xfs_fsr > copies data between files where doing so may be unnecessary and thus > inefficient for lower level tests. > > Add a basic swapext command to xfs_io that allows userspace > invocation of the command under more controlled conditions. This > facilites targeted tests without interference from xfs_fsr policy, > such as using files with only preallocated extents, known/expected > failure cases, etc. This command makes no effort to retain data > across the operation. As such, it is for testing purposes only. > > Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> Looks ok, Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --D -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
