On Fri, Apr 9, 2021 at 4:39 PM Luis Henriques <lhenriques@xxxxxxx> wrote: > > Nicolas Boichat <drinkcat@xxxxxxxxxxxx> writes: > > > On Wed, Feb 24, 2021 at 6:44 PM Nicolas Boichat <drinkcat@xxxxxxxxxxxx> wrote: > >> > >> On Wed, Feb 24, 2021 at 6:22 PM Luis Henriques <lhenriques@xxxxxxx> wrote: > >> > > >> > On Tue, Feb 23, 2021 at 08:00:54PM -0500, Olga Kornievskaia wrote: > >> > > On Mon, Feb 22, 2021 at 5:25 AM Luis Henriques <lhenriques@xxxxxxx> wrote: > >> > > > > >> > > > A regression has been reported by Nicolas Boichat, found while using the > >> > > > copy_file_range syscall to copy a tracefs file. Before commit > >> > > > 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices") the > >> > > > kernel would return -EXDEV to userspace when trying to copy a file across > >> > > > different filesystems. After this commit, the syscall doesn't fail anymore > >> > > > and instead returns zero (zero bytes copied), as this file's content is > >> > > > generated on-the-fly and thus reports a size of zero. > >> > > > > >> > > > This patch restores some cross-filesystem copy restrictions that existed > >> > > > prior to commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across > >> > > > devices"). Filesystems are still allowed to fall-back to the VFS > >> > > > generic_copy_file_range() implementation, but that has now to be done > >> > > > explicitly. > >> > > > > >> > > > nfsd is also modified to fall-back into generic_copy_file_range() in case > >> > > > vfs_copy_file_range() fails with -EOPNOTSUPP or -EXDEV. > >> > > > > >> > > > Fixes: 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices") > >> > > > Link: https://lore.kernel.org/linux-fsdevel/20210212044405.4120619-1-drinkcat@xxxxxxxxxxxx/ > >> > > > Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@xxxxxxxxxxxxxx/ > >> > > > Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/ > >> > > > Reported-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > >> > > > Signed-off-by: Luis Henriques <lhenriques@xxxxxxx> > >> > > > >> > > I tested v8 and I believe it works for NFS. > >> > > >> > Thanks a lot for the testing. And to everyone else for reviews, > >> > feedback,... and patience. > >> > >> Thanks so much to you!!! > >> > >> Works here, you can add my > >> Tested-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > > > > What happened to this patch? It does not seem to have been picked up > > yet? Any reason why? > > Hmm... good question. I'm not actually sure who would be picking it. Al, > maybe...? > Darrick, Would you mind taking this through your tree in case Al doesn't pick it up? Thanks, Amir.