[CRIU] [PATCH] fsnotify: Filter event mask from old kernels

[Cyrill Gorcunov]

From: Cyrill Gorcunov <gorcunov at virtuozzo.com>

When checkpoint is done on the kernels where
commit 6933599697c96c3213c95f5f1fc7cb6abfd08c54
is not yet present then mask is not filtered
and saved in image in this raw form.

For such case restore on more modern kernels
will fail because only a small set of events
are allowed to pass from userspace.

Signed-off-by: Cyrill Gorcunov <gorcunov at virtuozzo.com>
---
 criu/fsnotify.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/criu/fsnotify.c b/criu/fsnotify.c
index c26e5c6ec387..955cd106b3cb 100644
--- a/criu/fsnotify.c
+++ b/criu/fsnotify.c
@@ -556,12 +556,19 @@ static int restore_one_inotify(int inotify_fd, struct fsnotify_mark_info *info)
 	InotifyWdEntry *iwe = info->iwe;
 	int ret = -1, target = -1;
 	char buf[PSFDS], *path;
+	uint32_t mask;
 
 	path = get_mark_path("inotify", info->remap, iwe->f_handle,
 			     iwe->i_ino, iwe->s_dev, buf, &target);
 	if (!path)
 		goto err;
 
+	mask = iwe->mask & IN_ALL_EVENTS;
+	if (iwe->mask & ~IN_ALL_EVENTS) {
+		pr_info("\t\tfilter event mask %#x -> %#x\n",
+			iwe->mask, mask);
+	}
+
 	/*
 	 * FIXME The kernel allocates wd-s sequentially,
 	 * this is suboptimal, but the kernel doesn't
@@ -570,7 +577,7 @@ static int restore_one_inotify(int inotify_fd, struct fsnotify_mark_info *info)
 	while (1) {
 		int wd;
 
-		wd = inotify_add_watch(inotify_fd, path, iwe->mask);
+		wd = inotify_add_watch(inotify_fd, path, mask);
 		if (wd < 0) {
 			pr_perror("Can't add watch for 0x%x with 0x%x", inotify_fd, iwe->wd);
 			break;
-- 
2.7.5