Rahul Sundaram wrote: > Eric Sandeen wrote: >> James Ralston wrote: >> >>> If the latter, is there an interface for fallocate() that doesn't have >>> quite as much FAIL as posix_fallocate()? >> yes, plain ol' fallocate(2), I think: >> >> #include <linux/falloc.h> >> >> long fallocate(int fd, int mode, loff_t offset, loff_t len); >> >> but you need a very recent glibc to get it: >> >> http://sourceware.org/bugzilla/show_bug.cgi?id=7083#c1 >> >> it'd be great if we could get that into F11... >> >> BTW, ext4, xfs, btrfs, and ocfs2 all support ->fallocate. > > Shouldn't we getting the new glibc and file RFE's against RPM, the > torrent clients etc? Ah, just checked and it's already in our rawhide glibc, yay :) didn't realize that. http://sandeen.fedorapeople.org/utilities/fallocate.c is a simple tool to exercise it, FWIW. One caveat: ext4 doesn't always coalesce extents, so preallocating for, say, bittorent won't necessarily get ext4 down to tracking a single extent; in my testing it can still have thousands of extents tracked by the filesystem even if they are adjacent/contiguous. :( I hope to fix that. It's still worth doing though; a thousand adjacent extents is better than a thousand discontiguous extents. -Eric -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
