[systemd-commits] 2 commits - src/path.c TODO

[Lennart Poettering]

 TODO       |    3 ---
 src/path.c |   28 ++++++++++++++++++----------
 2 files changed, 18 insertions(+), 13 deletions(-)

New commits:
commit 0595f9a1c182a84581749823ef47c5f292e545f9
Author: Lennart Poettering <lennart at poettering.net>
Date:   Fri Mar 4 01:49:37 2011 +0100

    path: after installing inotify watches, recheck file again to fix race

diff --git a/src/path.c b/src/path.c
index 1455b47..f7878b5 100644
--- a/src/path.c
+++ b/src/path.c
@@ -282,7 +282,7 @@ static void path_set_state(Path *p, PathState state) {
         unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], true);
 }
 
-static void path_enter_waiting(Path *p, bool initial, bool recheck);
+static void path_enter_waiting(Path *p, bool initial, bool recheck, bool skip_watch);
 
 static int path_coldplug(Unit *u) {
         Path *p = PATH(u);
@@ -294,7 +294,7 @@ static int path_coldplug(Unit *u) {
 
                 if (p->deserialized_state == PATH_WAITING ||
                     p->deserialized_state == PATH_RUNNING)
-                        path_enter_waiting(p, true, true);
+                        path_enter_waiting(p, true, true, false);
                 else
                         path_set_state(p, p->deserialized_state);
         }
@@ -341,7 +341,7 @@ fail:
 }
 
 
-static void path_enter_waiting(Path *p, bool initial, bool recheck) {
+static void path_enter_waiting(Path *p, bool initial, bool recheck, bool skip_watch) {
         PathSpec *s;
         int r;
         bool good = false;
@@ -389,8 +389,16 @@ static void path_enter_waiting(Path *p, bool initial, bool recheck) {
         }
 
 waiting:
-        if ((r = path_watch(p)) < 0)
-                goto fail;
+        if (!skip_watch) {
+                if ((r = path_watch(p)) < 0)
+                        goto fail;
+
+                /* Hmm, so now we have created inotify watches, but the file
+                 * might have appeared/been removed by now, so we must
+                 * recheck */
+                path_enter_waiting(p, false, true, true);
+                return;
+        }
 
         path_set_state(p, PATH_WAITING);
         return;
@@ -410,7 +418,7 @@ static int path_start(Unit *u) {
                 return -ENOENT;
 
         p->failure = false;
-        path_enter_waiting(p, true, true);
+        path_enter_waiting(p, true, true, false);
 
         return 0;
 }
@@ -541,7 +549,7 @@ static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
         if (changed)
                 path_enter_running(p);
         else
-                path_enter_waiting(p, false, true);
+                path_enter_waiting(p, false, true, false);
 
         free(buf);
 
@@ -590,7 +598,7 @@ void path_unit_notify(Unit *u, UnitActiveState new_state) {
                         /* Hmm, so inotify was triggered since the
                          * last activation, so I guess we need to
                          * recheck what is going on. */
-                        path_enter_waiting(p, false, p->inotify_triggered);
+                        path_enter_waiting(p, false, p->inotify_triggered, false);
                 }
         }
 

commit 3fc546f93d92c09188d5018ea47def33b149c2e9
Author: Lennart Poettering <lennart at poettering.net>
Date:   Fri Mar 4 00:22:00 2011 +0100

    path: don't use IN_ATTRIB on parent dirs when watching a file, since those cannot be removed without emptying the dir first anyway and we need IN_ATTRIB only to detect the link count dropping to 0

diff --git a/TODO b/TODO
index 820391d..36c738e 100644
--- a/TODO
+++ b/TODO
@@ -11,9 +11,6 @@ F15:
 * load EnvironmentFile= when starting services, not when reloading configuration
   https://bugzilla.redhat.com/show_bug.cgi?id=661282
 
-* drop IN_ATTRIB from inotify watches for .path units where possible to avoid
-  lots of wakeups due to /dev changing when we watch a subdir of /dev.
-
 * NFS, networkmanager ordering issue
 
 * add fstab fields to add wait timeouts, change Wants to Requires by local-fs.target
diff --git a/src/path.c b/src/path.c
index bd40ab6..1455b47 100644
--- a/src/path.c
+++ b/src/path.c
@@ -223,9 +223,9 @@ static int path_watch_one(Path *p, PathSpec *s) {
                 /* Trim the path at the last slash. Keep the slash if it's the root dir. */
                 slash[slash == k] = 0;
 
-                flags = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB;
+                flags = IN_MOVE_SELF;
                 if (!exists)
-                        flags |= IN_CREATE | IN_MOVED_TO;
+                        flags |= IN_DELETE_SELF | IN_ATTRIB | IN_CREATE | IN_MOVED_TO;
 
                 if (inotify_add_watch(s->inotify_fd, k, flags) >= 0)
                         exists = true;