On Fri, Apr 7, 2017 at 11:01 AM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > truncate an overlayfs inode was checking IS_APPEND() on > overlay inode, but overlay inode does not have the S_APPEND flag. > > Move the IS_APPEND() check to after we have the upperdentry > and pass it the real upper inode. Not sure the reordering is worth it. Just use d_real_inode() in the IS_APPEND() check. OTOH it shouldn't matter (well, except whether the file is copied up or not in the error caae ). But mainly I just feel when there's a choice of a simpler way we should use that. Also it's usually better not to mix fixes with cleanups (the d_inode() thing). Thanks, Miklos > > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > --- > fs/open.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/fs/open.c b/fs/open.c > index b7d5ab1..425db52 100644 > --- a/fs/open.c > +++ b/fs/open.c > @@ -87,10 +87,6 @@ long vfs_truncate(const struct path *path, loff_t length) > if (error) > goto mnt_drop_write_and_out; > > - error = -EPERM; > - if (IS_APPEND(inode)) > - goto mnt_drop_write_and_out; > - > /* > * If this is an overlayfs then do as if opening the file so we get > * write access on the upper inode, not on the overlay inode. For > @@ -101,7 +97,11 @@ long vfs_truncate(const struct path *path, loff_t length) > if (IS_ERR(upperdentry)) > goto mnt_drop_write_and_out; > > - error = get_write_access(upperdentry->d_inode); > + error = -EPERM; > + if (IS_APPEND(d_inode(upperdentry))) > + goto mnt_drop_write_and_out; > + > + error = get_write_access(d_inode(upperdentry)); > if (error) > goto mnt_drop_write_and_out; > > @@ -120,7 +120,7 @@ long vfs_truncate(const struct path *path, loff_t length) > error = do_truncate(path->dentry, length, 0, NULL); > > put_write_and_out: > - put_write_access(upperdentry->d_inode); > + put_write_access(d_inode(upperdentry)); > mnt_drop_write_and_out: > mnt_drop_write(path->mnt); > out: > -- > 2.7.4 >
