Messages in this thread | | | Date | Wed, 24 Feb 2021 10:23:25 +0000 | From | Luis Henriques <> | Subject | Re: [PATCH v8] vfs: fix copy_file_range regression in cross-fs copies |
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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@suse.de> 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@chromium.org/ > > Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@mail.gmail.com/ > > Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/ > > Reported-by: Nicolas Boichat <drinkcat@chromium.org> > > Signed-off-by: Luis Henriques <lhenriques@suse.de> > > 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.
I'll now go look into the manpage and see what needs to be changed.
Cheers, -- Luís
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