| Message ID | 151603745169.29035.6866708909114015882.stgit@rabbit.intern.cm-ag (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 15, 2018 at 06:30:51PM +0100, Max Kellermann wrote: > nfs/super: set MS_POSIXACL only if ACL support is enabled > > The code comment says "We will [apply the umask] ourselves", but that > happens in posix_acl_create() only if the kernel has POSIX ACL > support. Without it, posix_acl_create() is a is an empty dummy > function. <snip> Your subject line is a bit odd :(
On 2018/01/15 18:41, Greg KH <gregkh@linuxfoundation.org> wrote:
> Your subject line is a bit odd :(
True, I already repaired & resent it. Sorry for the hiccup.
On Mon, 2018-01-15 at 18:30 +0100, Max Kellermann wrote: > nfs/super: set MS_POSIXACL only if ACL support is enabled > > The code comment says "We will [apply the umask] ourselves", but that > happens in posix_acl_create() only if the kernel has POSIX ACL > support. Without it, posix_acl_create() is a is an empty dummy > function. > > So let's not pretend we will apply the umask if we can already know > that we will never. > > This fixes a problem where the umask is always ignored in the NFS > client when compiled without CONFIG_FS_POSIX_ACL. This is a 4 year > old regression caused by commit 013cdf1088d723 which itself was not > completely wrong, but failed to consider all the side effects by > misdesigned VFS code. > > There are two compile-time checks and one runtime check: > > - If CONFIG_FS_POSIX_ACL=n, then MS_POSIXACL is never set. > > - If CONFIG_FS_POSIX_ACL=y and CONFIG_NFS_V3_ACL=n, then only NFSv4 > has ACL support (and cannot be disabled), and we need to check for > "version==4". > > - If CONFIG_FS_POSIX_ACL=y and CONFIG_NFS_V3_ACL=y, MS_POSIXACL is > always set, as before. > > Signed-off-by: Max Kellermann <mk@cm4all.com> > --- > fs/nfs/super.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/fs/nfs/super.c b/fs/nfs/super.c > index 216f67d628b3..ec4e1f2775e0 100644 > --- a/fs/nfs/super.c > +++ b/fs/nfs/super.c > @@ -2338,10 +2338,17 @@ void nfs_fill_super(struct super_block *sb, > struct nfs_mount_info *mount_info) > sb->s_blocksize = nfs_block_size(data->bsize, &sb- > >s_blocksize_bits); > > if (server->nfs_client->rpc_ops->version != 2) { > - /* The VFS shouldn't apply the umask to mode bits. > We will do > - * so ourselves when necessary. > - */ > - sb->s_flags |= MS_POSIXACL; > +#ifdef CONFIG_FS_POSIX_ACL > +#ifndef CONFIG_NFS_V3_ACL > + if (nfss->nfs_client->rpc_ops->version == 4) > +#endif > + /* The VFS shouldn't apply the umask to mode > + * bits. We will do so ourselves when > + * necessary. > + */ > + sb->s_flags |= MS_POSIXACL; > +#endif > + > sb->s_time_gran = 1; > sb->s_export_op = &nfs_export_ops; > } The above illustrates exactly why I've asked people _never_ to make anything conditional on rpc_ops->version. Please use a NFS capability (i.e. NFS_SB(sb)->caps) for this kind of thing. That expresses the condition in terms of the functionality we want instead of a whimsical protocol version number. Thanks Trond -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@primarydata.com
diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 216f67d628b3..ec4e1f2775e0 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2338,10 +2338,17 @@ void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info) sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits); if (server->nfs_client->rpc_ops->version != 2) { - /* The VFS shouldn't apply the umask to mode bits. We will do - * so ourselves when necessary. - */ - sb->s_flags |= MS_POSIXACL; +#ifdef CONFIG_FS_POSIX_ACL +#ifndef CONFIG_NFS_V3_ACL + if (nfss->nfs_client->rpc_ops->version == 4) +#endif + /* The VFS shouldn't apply the umask to mode + * bits. We will do so ourselves when + * necessary. + */ + sb->s_flags |= MS_POSIXACL; +#endif + sb->s_time_gran = 1; sb->s_export_op = &nfs_export_ops; }
nfs/super: set MS_POSIXACL only if ACL support is enabled The code comment says "We will [apply the umask] ourselves", but that happens in posix_acl_create() only if the kernel has POSIX ACL support. Without it, posix_acl_create() is a is an empty dummy function. So let's not pretend we will apply the umask if we can already know that we will never. This fixes a problem where the umask is always ignored in the NFS client when compiled without CONFIG_FS_POSIX_ACL. This is a 4 year old regression caused by commit 013cdf1088d723 which itself was not completely wrong, but failed to consider all the side effects by misdesigned VFS code. There are two compile-time checks and one runtime check: - If CONFIG_FS_POSIX_ACL=n, then MS_POSIXACL is never set. - If CONFIG_FS_POSIX_ACL=y and CONFIG_NFS_V3_ACL=n, then only NFSv4 has ACL support (and cannot be disabled), and we need to check for "version==4". - If CONFIG_FS_POSIX_ACL=y and CONFIG_NFS_V3_ACL=y, MS_POSIXACL is always set, as before. Signed-off-by: Max Kellermann <mk@cm4all.com> --- fs/nfs/super.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)