1 files changed, 22 insertions, 15 deletions

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 695978b27497..96dc18b73cf0 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -507,8 +507,6 @@ xfs_setattr(
                  * that the group ID supplied to the chown() function
                  * shall be equal to either the group ID or one of the
                  * supplementary group IDs of the calling process.
-                 *
-                 * XXX: How does restricted_chown affect projid?
                  */
                 if (restricted_chown &&
                     (iuid != uid || (igid != gid &&
@@ -860,6 +858,8 @@ xfs_setattr(
                                 di_flags |= XFS_DIFLAG_NOATIME;
                         if (vap->va_xflags & XFS_XFLAG_NODUMP)
                                 di_flags |= XFS_DIFLAG_NODUMP;
+                        if (vap->va_xflags & XFS_XFLAG_PROJINHERIT)
+                                di_flags |= XFS_DIFLAG_PROJINHERIT;
                         if ((ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
                                 if (vap->va_xflags & XFS_XFLAG_RTINHERIT)
                                         di_flags |= XFS_DIFLAG_RTINHERIT;
@@ -1915,7 +1915,9 @@ xfs_create(
         /* Return through std_return after this point. */
 
         udqp = gdqp = NULL;
-        if (vap->va_mask & XFS_AT_PROJID)
+        if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+                prid = dp->i_d.di_projid;
+        else if (vap->va_mask & XFS_AT_PROJID)
                 prid = (xfs_prid_t)vap->va_projid;
         else
                 prid = (xfs_prid_t)dfltprid;
@@ -2621,17 +2623,7 @@ xfs_link(
         if (src_vp->v_type == VDIR)
                 return XFS_ERROR(EPERM);
 
-        /*
-         * For now, manually find the XFS behavior descriptor for
-         * the source vnode.  If it doesn't exist then something
-         * is wrong and we should just return an error.
-         * Eventually we need to figure out how link is going to
-         * work in the face of stacked vnodes.
-         */
         src_bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(src_vp), &xfs_vnodeops);
-        if (src_bdp == NULL) {
-                return XFS_ERROR(EXDEV);
-        }
         sip = XFS_BHVTOI(src_bdp);
         tdp = XFS_BHVTOI(target_dir_bdp);
         mp = tdp->i_mount;
@@ -2698,6 +2690,17 @@ xfs_link(
                 goto error_return;
         }
 
+        /*
+         * If we are using project inheritance, we only allow hard link
+         * creation in our tree when the project IDs are the same; else
+         * the tree quota mechanism could be circumvented.
+         */
+        if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
+                     (tdp->i_d.di_projid != sip->i_d.di_projid))) {
+                error = XFS_ERROR(EPERM);
+                goto error_return;
+        }
+
         if (resblks == 0 &&
             (error = XFS_DIR_CANENTER(mp, tp, tdp, target_name,
                         target_namelen)))
@@ -2820,7 +2823,9 @@ xfs_mkdir(
 
         mp = dp->i_mount;
         udqp = gdqp = NULL;
-        if (vap->va_mask & XFS_AT_PROJID)
+        if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+                prid = dp->i_d.di_projid;
+        else if (vap->va_mask & XFS_AT_PROJID)
                 prid = (xfs_prid_t)vap->va_projid;
         else
                 prid = (xfs_prid_t)dfltprid;
@@ -3374,7 +3379,9 @@ xfs_symlink(
         /* Return through std_return after this point. */
 
         udqp = gdqp = NULL;
-        if (vap->va_mask & XFS_AT_PROJID)
+        if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+                prid = dp->i_d.di_projid;
+        else if (vap->va_mask & XFS_AT_PROJID)
                 prid = (xfs_prid_t)vap->va_projid;
         else
                 prid = (xfs_prid_t)dfltprid;