Btrfs: Handle SGID bit when creating inodes

Before this patch, new files/dirs would ignore the SGID bit on their
parent directory and always be owned by the creating user's uid/gid.

Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 95ea58cb3065..5792816d4fca 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3472,7 +3472,14 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
                 root->highest_inode = objectid;
 
         inode->i_uid = current_fsuid();
-        inode->i_gid = current_fsgid();
+
+        if (dir->i_mode & S_ISGID) {
+                inode->i_gid = dir->i_gid;
+                if (S_ISDIR(mode))
+                        mode |= S_ISGID;
+        } else
+                inode->i_gid = current_fsgid();
+
         inode->i_mode = mode;
         inode->i_ino = objectid;
         inode_set_bytes(inode, 0);