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diff --git a/sys/kern/vfs_inotify.c b/sys/kern/vfs_inotify.c
--- a/sys/kern/vfs_inotify.c
+++ b/sys/kern/vfs_inotify.c
@@ -34,6 +34,7 @@
#include <sys/sysent.h>
#include <sys/syslimits.h>
#include <sys/sysproto.h>
+#include <sys/taskqueue.h>
#include <sys/tree.h>
#include <sys/user.h>
#include <sys/vnode.h>
@@ -168,6 +169,8 @@
size_t nbpending; /* bytes available to read */
uint64_t ino; /* unique identifier */
struct inotify_watch_tree watches; /* active watches */
+ TAILQ_HEAD(, inotify_watch) deadwatches; /* watches pending vrele() */
+ struct task reaptask; /* task to reap dead watches */
struct selinfo sel; /* select/poll/kevent info */
struct ucred *cred; /* credential ref */
};
@@ -374,6 +377,13 @@
vn_irflag_unset(vp, VIRF_INOTIFY);
}
+static void
+inotify_free_watch(struct inotify_watch *watch)
+{
+ vrele(watch->vp);
+ free(watch, M_INOTIFY);
+}
+
/*
* Assumes that the watch has already been removed from its softc.
*/
@@ -389,9 +399,24 @@
mtx_lock(&vp->v_pollinfo->vpi_lock);
inotify_unlink_watch_locked(sc, watch);
mtx_unlock(&vp->v_pollinfo->vpi_lock);
+ inotify_free_watch(watch);
+}
- vrele(vp);
- free(watch, M_INOTIFY);
+static void
+inotify_reap(void *arg, int pending)
+{
+ struct inotify_softc *sc;
+ struct inotify_watch *watch;
+
+ sc = arg;
+ mtx_lock(&sc->lock);
+ while ((watch = TAILQ_FIRST(&sc->deadwatches)) != NULL) {
+ TAILQ_REMOVE(&sc->deadwatches, watch, vlink);
+ mtx_unlock(&sc->lock);
+ inotify_free_watch(watch);
+ mtx_lock(&sc->lock);
+ }
+ mtx_unlock(&sc->lock);
}
static int
@@ -403,6 +428,7 @@
sc = fp->f_data;
+ /* Detach watches from their vnodes. */
mtx_lock(&sc->lock);
(void)chginotifycnt(sc->cred->cr_ruidinfo, -1, 0);
while ((watch = RB_MIN(inotify_watch_tree, &sc->watches)) != NULL) {
@@ -411,6 +437,17 @@
inotify_remove_watch(watch);
mtx_lock(&sc->lock);
}
+
+ /* Make sure that any asynchronous vrele() calls are done. */
+ mtx_unlock(&sc->lock);
+ taskqueue_drain(taskqueue_thread, &sc->reaptask);
+ mtx_lock(&sc->lock);
+ KASSERT(RB_EMPTY(&sc->watches),
+ ("%s: watches not empty in %p", __func__, sc));
+ KASSERT(TAILQ_EMPTY(&sc->deadwatches),
+ ("%s: deadwatches not empty in %p", __func__, sc));
+
+ /* Drop pending events. */
while (!STAILQ_EMPTY(&sc->pending)) {
rec = inotify_dequeue(sc);
if (rec != &sc->overflow)
@@ -456,6 +493,8 @@
sc->nextwatch = 1; /* Required for compatibility. */
STAILQ_INIT(&sc->pending);
RB_INIT(&sc->watches);
+ TAILQ_INIT(&sc->deadwatches);
+ TASK_INIT(&sc->reaptask, 0, inotify_reap, sc);
mtx_init(&sc->lock, "inotify", NULL, MTX_DEF);
knlist_init_mtx(&sc->sel.si_note, &sc->lock);
sc->cred = crhold(td->td_ucred);
@@ -560,17 +599,16 @@
return (true);
}
-static int
+static void
inotify_log_one(struct inotify_watch *watch, const char *name, size_t namelen,
int event, uint32_t cookie)
{
struct inotify_watch key;
struct inotify_softc *sc;
struct inotify_record *rec;
- int relecount;
bool allocfail;
- relecount = 0;
+ mtx_assert(&watch->vp->v_pollinfo->vpi_lock, MA_OWNED);
sc = watch->sc;
rec = inotify_alloc_record(watch->wd, name, namelen, event, cookie,
@@ -599,20 +637,22 @@
/*
* Remove the watch, taking care to handle races with
- * inotify_close().
+ * inotify_close(). The thread that removes the watch is
+ * responsible for freeing it.
*/
key.wd = watch->wd;
if (RB_FIND(inotify_watch_tree, &sc->watches, &key) != NULL) {
RB_REMOVE(inotify_watch_tree, &sc->watches, watch);
inotify_unlink_watch_locked(sc, watch);
- free(watch, M_INOTIFY);
- /* Defer vrele() to until locks are dropped. */
- relecount++;
+ /*
+ * Defer the vrele() to a sleepable thread context.
+ */
+ TAILQ_INSERT_TAIL(&sc->deadwatches, watch, vlink);
+ taskqueue_enqueue(taskqueue_thread, &sc->reaptask);
}
}
mtx_unlock(&sc->lock);
- return (relecount);
}
void
@@ -620,25 +660,18 @@
uint32_t cookie)
{
struct inotify_watch *watch, *tmp;
- int relecount;
KASSERT((event & ~(IN_ALL_EVENTS | IN_ISDIR | IN_UNMOUNT)) == 0,
("inotify_log: invalid event %#x", event));
- relecount = 0;
mtx_lock(&vp->v_pollinfo->vpi_lock);
TAILQ_FOREACH_SAFE(watch, &vp->v_pollinfo->vpi_inotify, vlink, tmp) {
KASSERT(watch->vp == vp,
("inotify_log: watch %p vp != vp", watch));
- if ((watch->mask & event) != 0 || event == IN_UNMOUNT) {
- relecount += inotify_log_one(watch, name, namelen, event,
- cookie);
- }
+ if ((watch->mask & event) != 0 || event == IN_UNMOUNT)
+ inotify_log_one(watch, name, namelen, event, cookie);
}
mtx_unlock(&vp->v_pollinfo->vpi_lock);
-
- for (int i = 0; i < relecount; i++)
- vrele(vp);
}
/*

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