* Sage Weil (sage@newdream.net) [091216 17:55]:> On Wed, 16 Dec 2009, Li Dongyang wrote: > > > Have a look at line 998, ioctl.c, inside btrfs_ioctl_clone(), > > the src->i_size(the size of the testfile created by touch) is just 0, and this > > will cause btrfs_ioctl_clone just return -EINVAL. > > I''m not sure if it makes sense to clone a file which actually doesn''t have any > > data extents. > > Probably not, but it seems more consistent to return success instead than > -EINVAL. Requiring the caller to check and special case empty files isn''t > very friendly...Actually it makes lots of sense if trying to e.g. cow-copy an chroot on an buildd, and there are some empty files inside of the linux installation (which normally just are). Can I hope on getting the patch (or another patch) incorporated into the kernel? Cheers, Andi -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jan 27, 2010 at 11:53:22AM +0100, Andreas Barth wrote:> * Sage Weil (sage@newdream.net) [091216 17:55]: > > On Wed, 16 Dec 2009, Li Dongyang wrote: > > > > > Have a look at line 998, ioctl.c, inside btrfs_ioctl_clone(), > > > the src->i_size(the size of the testfile created by touch) is just 0, and this > > > will cause btrfs_ioctl_clone just return -EINVAL. > > > I''m not sure if it makes sense to clone a file which actually doesn''t have any > > > data extents. > > > > Probably not, but it seems more consistent to return success instead than > > -EINVAL. Requiring the caller to check and special case empty files isn''t > > very friendly... > > > Actually it makes lots of sense if trying to e.g. cow-copy an chroot > on an buildd, and there are some empty files inside of the linux > installation (which normally just are). > > Can I hope on getting the patch (or another patch) incorporated into > the kernel?In this case the application is responsible for duplicating the file. The clone ioctl doesn''t actually clone any of the file metadata or anything else. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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