From 877522adb8a30de0023464cba0e597104e93cccc Mon Sep 17 00:00:00 2001 From: Raghavendra G Date: Fri, 13 Nov 2009 16:04:47 +0000 Subject: transport/ib-verbs: synchronize ib_verbs_recv_completion_proc with ib_verbs_receive so that the former doesn't overwrite the pointer from which latter reads. - There can be a condition wherein, 1. the thread executing ib_verbs_recv_completion_proc (thr 1) stores the buffer pointer and notifies the upper translators about a POLLIN event. 2. the thread waiting for events on socket (thr 2) calls transport_receive, but in ib_verbs_receive it has not still read the data. 3. thr 1 receives work completion event for another work request and overwrites the buffer pointer. 4. thr 2 reads from the new pointer there by missing the data stored in buffer pointed by pointer which got overwritten. Signed-off-by: Raghavendra G Signed-off-by: Anand V. Avati BUG: 382 (Data can be lost before it is read in ib_verbs_receive.) URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=382 --- transport/ib-verbs/src/ib-verbs.c | 10 +++++----- transport/ib-verbs/src/ib-verbs.h | 1 + 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/transport/ib-verbs/src/ib-verbs.c b/transport/ib-verbs/src/ib-verbs.c index 8338587a5..d89a68928 100644 --- a/transport/ib-verbs/src/ib-verbs.c +++ b/transport/ib-verbs/src/ib-verbs.c @@ -497,7 +497,7 @@ ib_verbs_receive (transport_t *this, char **hdr_p, size_t *hdrlen_p, priv->data_ptr = NULL; data_len = priv->data_len; - /* pthread_cond_broadcast (&priv->recv_cond); */ + pthread_cond_broadcast (&priv->recv_cond); } pthread_mutex_unlock (&priv->recv_mutex); @@ -1137,9 +1137,9 @@ ib_verbs_recv_completion_proc (void *data) pthread_mutex_lock (&priv->recv_mutex); { -/* while (priv->data_ptr) - pthread_cond_wait (&priv->recv_cond, &priv->recv_mutex); -*/ + while (priv->data_ptr) + pthread_cond_wait (&priv->recv_cond, + &priv->recv_mutex); priv->data_ptr = post->buf; priv->data_offset = 0; @@ -1567,7 +1567,7 @@ ib_verbs_init (transport_t *this) pthread_mutex_init (&priv->read_mutex, NULL); pthread_mutex_init (&priv->write_mutex, NULL); pthread_mutex_init (&priv->recv_mutex, NULL); - /* pthread_cond_init (&priv->recv_cond, NULL); */ + pthread_cond_init (&priv->recv_cond, NULL); return 0; } diff --git a/transport/ib-verbs/src/ib-verbs.h b/transport/ib-verbs/src/ib-verbs.h index 0b61a2a60..2e38c009d 100644 --- a/transport/ib-verbs/src/ib-verbs.h +++ b/transport/ib-verbs/src/ib-verbs.h @@ -209,6 +209,7 @@ struct _ib_verbs_private { char handshake_ret; pthread_mutex_t recv_mutex; + pthread_cond_t recv_cond; /* used during ib_verbs_handshake */ struct { -- cgit