vfs_btrfs: Also call vfs_offload_token_ctx_init() in btrfs_offload_write_send()

If a client for whatever reason calls FSCTL_SRV_COPYCHUNK[_WRITE] without
FSCTL_SRV_REQUEST_RESUME_KEY, we call btrfs_offload_write_send
before btrfs_offload_read_send.

This is similar to 462b74da79c51f9ba6dbd24e603aa904485d5123

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15758

Signed-off-by: Andreas Schneider <asn@samba.org>

Autobuild-User(v4-21-test): Jule Anger <janger@samba.org>
Autobuild-Date(v4-21-test): Tue Dec  3 18:04:26 UTC 2024 on atb-devel-224

ctdb/common/run_event.c

@@ -268,8 +268,27 @@ static int run_event_script_status(struct run_event_script *script)
 	if (script->result.sig > 0) {
 		ret = -EINTR;
 	} else if (script->result.err > 0) {
-		if (script->result.err == EACCES) {
-			/* Map EACCESS to ENOEXEC */
+		if (script->result.err == EACCES ||
+		    script->result.err == ENOENT) {
+			/*
+			 * Map EACCESS/ENOENT to ENOEXEC
+			 *
+			 * ENOENT: Disabling a standard event script
+			 * by removing its symlink can result in
+			 * ENOENT.  This happens when the script list
+			 * is built while the link exists, but the
+			 * link is removed before the attempt to run
+			 * it.  Map it to ENOEXEC (which causes a
+			 * script to be shown as DISABLED).  This
+			 * makes it impossible to distinguish a
+			 * removed symlink from a dangling
+			 * symlink... but the latter can just be
+			 * defined as disabled.  It should be rare
+			 * because it shouldn't happen if event
+			 * scripts are properly managed.  If someone
+			 * is doing weird things then they can easily
+			 * debug such issues by looking at the link.
+			 */
 			ret = -ENOEXEC;
 		} else {
 			ret = -script->result.err;

ctdb/tests/UNIT/eventd/etc-ctdb/share/events/data/01.dummy.script

@@ -2,5 +2,9 @@
 
 case "$1" in
 "failure") exit 1 ;;
+"disablehack")
+	ctdb-event script disable data 02.disabled
+	ctdb-event script disable data 03.notalink
+	;;
 *) exit 0 ;;
 esac

ctdb/tests/UNIT/eventd/eventd_009.sh

@@ -153,3 +153,40 @@ ok <<EOF
 * 03.notalink
 EOF
 simple_test script list data
+
+#
+# Test disabling of scripts after the script list has been
+# built. Normally this would be an admin racing with eventd instead of
+# one script disabling subsequent ones.
+#
+
+# First enable all scripts - this might repeat some previous stuff
+ok_null
+simple_test script enable data 01.dummy
+ok_null
+simple_test script enable data 02.disabled
+ok_null
+simple_test script enable data 03.notalink
+
+# Confirm expected state
+ok <<EOF
+* 01.dummy
+* 02.disabled
+
+* 03.notalink
+EOF
+simple_test script list data
+
+# Now run the event that disables the subsequent scripts:
+# - 02.disabled has its link removed
+# - 03.notalink effectively has "chmod -x" applied
+ok_null
+simple_test run 10 data disablehack
+
+# Confirm that both subsequent scripts were disabled
+ok <<EOF
+01.dummy             OK         DURATION DATETIME
+02.disabled          DISABLED  
+03.notalink          DISABLED  
+EOF
+simple_test status data disablehack

source3/modules/vfs_btrfs.c

@@ -261,6 +261,12 @@ static struct tevent_req *btrfs_offload_write_send(struct vfs_handle_struct *han
 
 	state->handle = handle;
 
+	status = vfs_offload_token_ctx_init(handle->conn->sconn->client,
+					    &btrfs_offload_ctx);
+	if (tevent_req_nterror(req, status)) {
+		return tevent_req_post(req, ev);
+	}
+
 	tevent_req_set_cleanup_fn(req, btrfs_offload_write_cleanup);
 
 	status = vfs_offload_token_db_fetch_fsp(btrfs_offload_ctx,