From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56344) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8izQ-0000Qn-LI for qemu-devel@nongnu.org; Wed, 18 Apr 2018 05:03:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f8izP-0005xb-DA for qemu-devel@nongnu.org; Wed, 18 Apr 2018 05:02:56 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53318 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f8izP-0005xM-7X for qemu-devel@nongnu.org; Wed, 18 Apr 2018 05:02:55 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C4D0A8DC4A for ; Wed, 18 Apr 2018 09:02:54 +0000 (UTC) From: Peter Xu Date: Wed, 18 Apr 2018 17:02:39 +0800 Message-Id: <20180418090239.13090-4-peterx@redhat.com> In-Reply-To: <20180418090239.13090-1-peterx@redhat.com> References: <20180418090239.13090-1-peterx@redhat.com> Subject: [Qemu-devel] [PATCH v2 3/3] monitor: add lock to protect mon_fdsets List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peterx@redhat.com, Eric Blake , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Markus Armbruster , Stefan Hajnoczi , "Dr . David Alan Gilbert" Similar to previous patch, but introduce a new global big lock for mon_fdsets. Take it where needed. Signed-off-by: Peter Xu --- monitor.c | 48 ++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 6 deletions(-) diff --git a/monitor.c b/monitor.c index f4951cafbc..40b5b56f66 100644 --- a/monitor.c +++ b/monitor.c @@ -254,6 +254,9 @@ typedef struct QMPRequest QMPRequest; /* Protects mon_list, monitor_event_state. */ static QemuMutex monitor_lock; +/* Protects mon_fdsets */ +static QemuMutex mon_fdsets_lock; + static QTAILQ_HEAD(mon_list, Monitor) mon_list; static QLIST_HEAD(mon_fdsets, MonFdset) mon_fdsets; static int mon_refcount; @@ -270,6 +273,16 @@ static QEMUClockType event_clock_type = QEMU_CLOCK_REALTIME; static void monitor_command_cb(void *opaque, const char *cmdline, void *readline_opaque); +/* + * This lock can be used very early, even during param parsing. + * Meanwhile it can also be used even at the end of main. Let's keep + * it initialized for the whole lifecycle of QEMU. + */ +static void __attribute__((constructor)) mon_fdsets_lock_init(void) +{ + qemu_mutex_init(&mon_fdsets_lock); +} + /** * Is @mon a QMP monitor? */ @@ -2308,9 +2321,11 @@ static void monitor_fdsets_cleanup(void) MonFdset *mon_fdset; MonFdset *mon_fdset_next; + qemu_mutex_lock(&mon_fdsets_lock); QLIST_FOREACH_SAFE(mon_fdset, &mon_fdsets, next, mon_fdset_next) { monitor_fdset_cleanup(mon_fdset); } + qemu_mutex_unlock(&mon_fdsets_lock); } AddfdInfo *qmp_add_fd(bool has_fdset_id, int64_t fdset_id, bool has_opaque, @@ -2345,6 +2360,7 @@ void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t fd, Error **errp) MonFdsetFd *mon_fdset_fd; char fd_str[60]; + qemu_mutex_lock(&mon_fdsets_lock); QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { if (mon_fdset->id != fdset_id) { continue; @@ -2364,10 +2380,12 @@ void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t fd, Error **errp) goto error; } monitor_fdset_cleanup(mon_fdset); + qemu_mutex_unlock(&mon_fdsets_lock); return; } error: + qemu_mutex_unlock(&mon_fdsets_lock); if (has_fd) { snprintf(fd_str, sizeof(fd_str), "fdset-id:%" PRId64 ", fd:%" PRId64, fdset_id, fd); @@ -2383,6 +2401,7 @@ FdsetInfoList *qmp_query_fdsets(Error **errp) MonFdsetFd *mon_fdset_fd; FdsetInfoList *fdset_list = NULL; + qemu_mutex_lock(&mon_fdsets_lock); QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { FdsetInfoList *fdset_info = g_malloc0(sizeof(*fdset_info)); FdsetFdInfoList *fdsetfd_list = NULL; @@ -2412,6 +2431,7 @@ FdsetInfoList *qmp_query_fdsets(Error **errp) fdset_info->next = fdset_list; fdset_list = fdset_info; } + qemu_mutex_unlock(&mon_fdsets_lock); return fdset_list; } @@ -2424,6 +2444,7 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, MonFdsetFd *mon_fdset_fd; AddfdInfo *fdinfo; + qemu_mutex_lock(&mon_fdsets_lock); if (has_fdset_id) { QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { /* Break if match found or match impossible due to ordering by ID */ @@ -2444,6 +2465,7 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, if (fdset_id < 0) { error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "fdset-id", "a non-negative value"); + qemu_mutex_unlock(&mon_fdsets_lock); return NULL; } /* Use specified fdset ID */ @@ -2494,6 +2516,7 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, fdinfo->fdset_id = mon_fdset->id; fdinfo->fd = mon_fdset_fd->fd; + qemu_mutex_unlock(&mon_fdsets_lock); return fdinfo; } @@ -2531,29 +2554,38 @@ int monitor_fdset_dup_fd_add(int64_t fdset_id, int dup_fd) { MonFdset *mon_fdset; MonFdsetFd *mon_fdset_fd_dup; + int ret = -1; + qemu_mutex_lock(&mon_fdsets_lock); QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { if (mon_fdset->id != fdset_id) { continue; } QLIST_FOREACH(mon_fdset_fd_dup, &mon_fdset->dup_fds, next) { if (mon_fdset_fd_dup->fd == dup_fd) { - return -1; + ret = -1; + goto out; } } mon_fdset_fd_dup = g_malloc0(sizeof(*mon_fdset_fd_dup)); mon_fdset_fd_dup->fd = dup_fd; QLIST_INSERT_HEAD(&mon_fdset->dup_fds, mon_fdset_fd_dup, next); - return 0; + ret = 0; + break; } - return -1; + +out: + qemu_mutex_unlock(&mon_fdsets_lock); + return ret; } static int monitor_fdset_dup_fd_find_remove(int dup_fd, bool remove) { MonFdset *mon_fdset; MonFdsetFd *mon_fdset_fd_dup; + int ret = -1; + qemu_mutex_lock(&mon_fdsets_lock); QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { QLIST_FOREACH(mon_fdset_fd_dup, &mon_fdset->dup_fds, next) { if (mon_fdset_fd_dup->fd == dup_fd) { @@ -2562,14 +2594,18 @@ static int monitor_fdset_dup_fd_find_remove(int dup_fd, bool remove) if (QLIST_EMPTY(&mon_fdset->dup_fds)) { monitor_fdset_cleanup(mon_fdset); } - return -1; + ret = -1; + goto out; } else { - return mon_fdset->id; + ret = mon_fdset->id; + goto out; } } } } - return -1; +out: + qemu_mutex_unlock(&mon_fdsets_lock); + return ret; } int monitor_fdset_dup_fd_find(int dup_fd) -- 2.14.3