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authorShyam <srangana@redhat.com>2015-01-08 13:56:08 -0500
committerRaghavendra G <rgowdapp@redhat.com>2015-01-12 21:14:52 -0800
commit3971315248c57386e05e6c8f57369a4571555cb2 (patch)
tree9728c3b139105d8bb08e2df3dbcf8abd7588d4ff /xlators/mount
parent9d37406b59fc33940c8e4e925ef9803b2d9b6507 (diff)
fuse: Fix cores in notify function when this is executed in parallel
The fuse notify function gets called by the epoll or the poll thread and till the point there is a single epoll thread, 2 notify instances would not race with each other. With the upcoming multi thread epoll changes, it is possible that 2 epoll threads invoke the notify function. As a result races in this function are fixed with this commit. The races seen are detailed in the bug, and the fix here is to enforce a (slightly) longer critical section when updating the fuse private structure and reserving state updates post error handling. Change-Id: I6974bc043cb59eb6dc39c5777123364dcefca358 BUG: 1180231 Signed-off-by: Shyam <srangana@redhat.com> Reviewed-on: http://review.gluster.org/9421 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Raghavendra G <rgowdapp@redhat.com> Tested-by: Raghavendra G <rgowdapp@redhat.com>
Diffstat (limited to 'xlators/mount')
-rw-r--r--xlators/mount/fuse/src/fuse-bridge.c59
-rw-r--r--xlators/mount/fuse/src/fuse-bridge.h4
2 files changed, 42 insertions, 21 deletions
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index cb345ad11f2..4e5adb33e44 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -5028,29 +5028,21 @@ fuse_graph_setup (xlator_t *this, glusterfs_graph_t *graph)
priv = this->private;
- /* handle the case of more than one CHILD_UP on same graph */
- if (priv->active_subvol == graph->top)
- return 0; /* This is a valid case */
-
pthread_mutex_lock (&priv->sync_mutex);
{
- if (graph->used) {
- pthread_mutex_unlock (&priv->sync_mutex);
- return 0;
+ /* handle the case of more than one CHILD_UP on same graph */
+ if ((priv->active_subvol == graph->top) || graph->used) {
+ goto unlock;
}
- graph->used = 1;
- }
- pthread_mutex_unlock (&priv->sync_mutex);
-
- itable = inode_table_new (0, graph->top);
- if (!itable)
- return -1;
+ itable = inode_table_new (0, graph->top);
+ if (!itable) {
+ ret = -1;
+ goto unlock;
+ }
- ((xlator_t *)graph->top)->itable = itable;
+ ((xlator_t *)graph->top)->itable = itable;
- pthread_mutex_lock (&priv->sync_mutex);
- {
prev_graph = priv->next_graph;
if ((prev_graph != NULL) && (prev_graph->id > graph->id)) {
@@ -5061,12 +5053,14 @@ fuse_graph_setup (xlator_t *this, glusterfs_graph_t *graph)
} else {
priv->next_graph = graph;
priv->event_recvd = 0;
-
- pthread_cond_signal (&priv->sync_cond);
}
if (prev_graph != NULL)
winds = ((xlator_t *)prev_graph->top)->winds;
+
+ /* set post initializing next_graph i to preserve
+ * critical section update and bails on error */
+ graph->used = 1;
}
pthread_mutex_unlock (&priv->sync_mutex);
@@ -5079,6 +5073,10 @@ fuse_graph_setup (xlator_t *this, glusterfs_graph_t *graph)
((graph) ? graph->id : 0));
return ret;
+unlock:
+ pthread_mutex_unlock (&priv->sync_mutex);
+
+ return ret;
}
@@ -5087,6 +5085,7 @@ notify (xlator_t *this, int32_t event, void *data, ...)
{
int32_t ret = 0;
fuse_private_t *private = NULL;
+ gf_boolean_t start_thread = _gf_false;
glusterfs_graph_t *graph = NULL;
private = this->private;
@@ -5122,9 +5121,16 @@ notify (xlator_t *this, int32_t event, void *data, ...)
pthread_mutex_unlock (&private->sync_mutex);
}
- if (!private->fuse_thread_started) {
- private->fuse_thread_started = 1;
+ pthread_mutex_lock (&private->sync_mutex);
+ {
+ if (!private->fuse_thread_started) {
+ private->fuse_thread_started = 1;
+ start_thread = _gf_true;
+ }
+ }
+ pthread_mutex_unlock (&private->sync_mutex);
+ if (start_thread) {
ret = gf_thread_create (&private->fuse_thread, NULL,
fuse_thread_proc, this);
if (ret != 0) {
@@ -5590,6 +5596,17 @@ fini (xlator_t *this_xl)
if ((priv = this_xl->private) == NULL)
return;
+ pthread_mutex_lock (&priv->sync_mutex);
+ {
+ if (!(priv->fini_invoked)) {
+ priv->fini_invoked = _gf_true;
+ } else {
+ pthread_mutex_unlock (&priv->sync_mutex);
+ return;
+ }
+ }
+ pthread_mutex_unlock (&priv->sync_mutex);
+
if (dict_get (this_xl->options, ZR_MOUNTPOINT_OPT))
mount_point = data_to_str (dict_get (this_xl->options,
ZR_MOUNTPOINT_OPT));
diff --git a/xlators/mount/fuse/src/fuse-bridge.h b/xlators/mount/fuse/src/fuse-bridge.h
index d0d4120026b..1a0d74cd4cd 100644
--- a/xlators/mount/fuse/src/fuse-bridge.h
+++ b/xlators/mount/fuse/src/fuse-bridge.h
@@ -128,6 +128,10 @@ struct fuse_private {
/* for using fuse-kernel readdirp*/
gf_boolean_t use_readdirp;
+
+ /* fini started, helps prevent multiple epoll worker threads
+ * firing up the fini routine */
+ gf_boolean_t fini_invoked;
};
typedef struct fuse_private fuse_private_t;