pseudo: Add may unlink patch

Mark files which are unlinked (nlink == 0) but open with fd's as
"may-unlink" to avoid problematic database entries.

(From OE-Core rev: e1e481f3608c05ab14c61bf45cd0837d7287b6a5)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/pseudo/files/mayunlink.patch

@@ -0,0 +1,37 @@
+Some operations may call unlink() on an open fd, then call fchown/fchmod/fstat
+on that fd. This would currently readd its entry to the database, which
+is necessary to preserve its permissions information however since that 
+file will be lost when it is closed, we don't want the DB entry to persist.
+Marking it as may_unlink means the code will know its likely been deleted 
+and ignore the entry later, giving improved behaviour that simple path
+mismatch warnings. We can use an nlink of zero to detect this.
+
+Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
+Upstream-Status: Pending
+
+Index: git/pseudo.c
+===================================================================
+--- git.orig/pseudo.c
++++ git/pseudo.c
+@@ -1100,6 +1100,21 @@ pseudo_op(pseudo_msg_t *msg, const char
+ 		break;
+ 	}
+ 
++	switch (msg->op) {
++	case OP_FCHOWN:		/* FALLTHROUGH */
++	case OP_FCHMOD:		/* FALLTHROUGH */
++	case OP_FSTAT:
++		if (!found_path && !found_ino && (msg->nlink == 0)) {
++			/* If nlink is 0 for an fchown/fchmod/fstat, we probably have an fd which is 
++			 * unlinked and we don't want to do inode/path matching against it. Marking it 
++ 			 * as may unlink gives the right hints in the database to ensure we
++			 * handle correctly whilst maintaining the permissions whilst the 
++			 * file exists for the fd.  */
++			pdb_may_unlink_file(msg, msg->client);
++		}
++		break;
++	}
++
+ op_exit:
+ 	/* in the case of an exact match, we just used the pointer
+ 	 * rather than allocating space.

meta/recipes-devtools/pseudo/pseudo_git.bb

@@ -7,6 +7,7 @@ SRC_URI = "git://git.yoctoproject.org/pseudo;branch=oe-core \
            file://abort_on_mismatch.patch \
            file://track_link_fds.patch \
            file://xattr_fix.patch \
+           file://mayunlink.patch \
            file://fallback-passwd \
            file://fallback-group \
            "