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authorXavier Hernandez <xhernandez@datalab.es>2015-06-18 16:44:55 +0200
committerPranith Kumar Karampuri <pkarampu@redhat.com>2015-06-18 23:33:38 -0700
commit4442449f1436e47c84c55c3f0d8f1a8b248db4b6 (patch)
tree52c6c2415c4264ff59faa8f7e209aeca036bf0a0 /xlators
parenta0e9c7d52dc43d30e1a2bd5567412a61b3c078fa (diff)
cluster/ec: Avoid parallel executions of the same state machine
In very rare circumstances it was possible that a subfop started by another fop could finish fast enough to cause that two or more instances of the same state machine be executing at the same time. Change-Id: I319924a18bd3f88115e751a66f8f4560435e0e0e BUG: 1233258 Signed-off-by: Xavier Hernandez <xhernandez@datalab.es> Reviewed-on: http://review.gluster.org/11317 Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com> Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Diffstat (limited to 'xlators')
-rw-r--r--xlators/cluster/ec/src/ec-common.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/xlators/cluster/ec/src/ec-common.c b/xlators/cluster/ec/src/ec-common.c
index e47297fb9ef..2a64f0ebb00 100644
--- a/xlators/cluster/ec/src/ec-common.c
+++ b/xlators/cluster/ec/src/ec-common.c
@@ -250,7 +250,7 @@ int32_t ec_check_complete(ec_fop_data_t * fop, ec_resume_f resume)
GF_ASSERT(fop->resume == NULL);
- if (fop->jobs != 0)
+ if (--fop->jobs != 0)
{
ec_trace("WAIT", fop, "resume=%p", resume);
@@ -1118,10 +1118,7 @@ int32_t ec_get_real_size_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
if (op_ret >= 0) {
link = fop->data;
- if (ec_dict_del_number(xdata, EC_XATTR_SIZE, &link->size) != 0) {
- gf_log(this->name, GF_LOG_WARNING,
- "Unable to determine real file size");
- }
+ link->size = buf->ia_size;
} else {
/* Prevent failure of parent fop. */
fop->error = 0;
@@ -1262,11 +1259,6 @@ void ec_lock(ec_fop_data_t *fop)
ec_lock_link_t *timer_link = NULL;
ec_lock_t *lock;
- /* There is a chance that ec_resume is called on fop even before ec_sleep.
- * Which can result in refs == 0 for fop leading to use after free in this
- * function when it calls ec_sleep so do ec_sleep at start and end of this
- * function.*/
- ec_sleep (fop);
while (fop->locked < fop->lock_count) {
/* Since there are only up to 2 locks per fop, this xor will change
* the order of the locks if fop->first_lock is 1. */
@@ -1331,7 +1323,6 @@ void ec_lock(ec_fop_data_t *fop)
timer_link = NULL;
}
}
- ec_resume (fop, 0);
if (timer_link != NULL) {
ec_resume(timer_link->fop, 0);
@@ -1876,6 +1867,17 @@ void __ec_manager(ec_fop_data_t * fop, int32_t error)
break;
}
+ /* At each state, fop must not be used anywhere else and there
+ * shouldn't be any pending subfop going on. */
+ GF_ASSERT(fop->jobs == 0);
+
+ /* While the manager is running we need to avoid that subfops launched
+ * from it could finish and call ec_resume() before the fop->handler
+ * has completed. This could lead to the same manager being executed
+ * by two threads concurrently. ec_check_complete() will take care of
+ * this reference. */
+ fop->jobs = 1;
+
fop->state = fop->handler(fop, fop->state);
error = ec_check_complete(fop, __ec_manager);