On Wed, Mar 30, 2016 at 11:27:55AM -0700, Darrick J. Wong wrote: > Or is it ok that fallocate could block, potentially for a long time as > we stream cows through the page cache (or however unshare works > internally)? Those same programs might not be expecting fallocate to > take a long time. Yes, it's perfectly fine for fallocate to block for long periods of time. See what gfs2 does during preallocation of blocks - it ends up calling sb_issue_zerout() because it doesn't have unwritten extents, and hence can block for long periods of time.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
