GFS2: Add S_NOSEC support

This adds S_NOSEC support to GFS2. We set/reset the flag either when
a user calls setattr or when we have just regained the glock
from another node. The flag is only set if there are no xattrs
on the inode and there is no suid bit set.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

3 files changed, 6 insertions, 2 deletions

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index a9f5cbe45cd9..bc2590ef5fc1 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -174,7 +174,9 @@ void gfs2_set_inode_flags(struct inode *inode)
         struct gfs2_inode *ip = GFS2_I(inode);
         unsigned int flags = inode->i_flags;
 
-        flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
+        flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
+        if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
+                inode->i_flags |= S_NOSEC;
         if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
                 flags |= S_IMMUTABLE;
         if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index a4222c3f5993..da21ecaafcc2 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -318,6 +318,8 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
         ip->i_generation = be64_to_cpu(str->di_generation);
 
         ip->i_diskflags = be32_to_cpu(str->di_flags);
+        ip->i_eattr = be64_to_cpu(str->di_eattr);
+        /* i_diskflags and i_eattr must be set before gfs2_set_inode_flags() */
         gfs2_set_inode_flags(&ip->i_inode);
         height = be16_to_cpu(str->di_height);
         if (unlikely(height > GFS2_MAX_META_HEIGHT))
@@ -330,7 +332,6 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
         ip->i_depth = (u8)depth;
         ip->i_entries = be32_to_cpu(str->di_entries);
 
-        ip->i_eattr = be64_to_cpu(str->di_eattr);
         if (S_ISREG(ip->i_inode.i_mode))
                 gfs2_set_aops(&ip->i_inode);
 
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 2a77071fb7b6..516516e0c2a2 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1094,6 +1094,7 @@ static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent
         if (sdp->sd_args.ar_nobarrier)
                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
 
+        sb->s_flags |= MS_NOSEC;
         sb->s_magic = GFS2_MAGIC;
         sb->s_op = &gfs2_super_ops;
         sb->s_d_op = &gfs2_dops;