Commit 9409fc05 authored by Peter Xu's avatar Peter Xu Committed by Markus Armbruster
Browse files

monitor: protect mon->fds with mon_lock 



mon->fds were protected by BQL.  Now protect it by mon_lock so that it
can even be used in monitor iothread.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <20180608035511.7439-3-peterx@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent dc7cbcd8

monitor.c

+18 −4
Original line number Diff line number Diff line
@@ -212,7 +212,6 @@ struct Monitor { 
    BlockCompletionFunc *password_completion_cb;

    void *password_opaque;

    mon_cmd_t *cmd_table;

    QLIST_HEAD(,mon_fd_t) fds;

    QTAILQ_ENTRY(Monitor) entry;



    /*
@@ -224,6 +223,7 @@ struct Monitor { 
    /*

     * Fields that are protected by the per-monitor lock.

     */

    QLIST_HEAD(, mon_fd_t) fds;

    QString *outbuf;

    guint out_watch;

    /* Read under either BQL or mon_lock, written with BQL+mon_lock.  */
@@ -2187,7 +2187,7 @@ static void hmp_acl_remove(Monitor *mon, const QDict *qdict) 
void qmp_getfd(const char *fdname, Error **errp)

{

    mon_fd_t *monfd;

    int fd;

    int fd, tmp_fd;



    fd = qemu_chr_fe_get_msgfd(&cur_mon->chr);

    if (fd == -1) {
@@ -2202,13 +2202,17 @@ void qmp_getfd(const char *fdname, Error **errp) 
        return;

    }



    qemu_mutex_lock(&cur_mon->mon_lock);

    QLIST_FOREACH(monfd, &cur_mon->fds, next) {

        if (strcmp(monfd->name, fdname) != 0) {

            continue;

        }



        close(monfd->fd);

        tmp_fd = monfd->fd;

        monfd->fd = fd;

        qemu_mutex_unlock(&cur_mon->mon_lock);

        /* Make sure close() is out of critical section */

        close(tmp_fd);

        return;

    }
@@ -2217,24 +2221,31 @@ void qmp_getfd(const char *fdname, Error **errp) 
    monfd->fd = fd;



    QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next);

    qemu_mutex_unlock(&cur_mon->mon_lock);

}



void qmp_closefd(const char *fdname, Error **errp)

{

    mon_fd_t *monfd;

    int tmp_fd;



    qemu_mutex_lock(&cur_mon->mon_lock);

    QLIST_FOREACH(monfd, &cur_mon->fds, next) {

        if (strcmp(monfd->name, fdname) != 0) {

            continue;

        }



        QLIST_REMOVE(monfd, next);

        close(monfd->fd);

        tmp_fd = monfd->fd;

        g_free(monfd->name);

        g_free(monfd);

        qemu_mutex_unlock(&cur_mon->mon_lock);

        /* Make sure close() is out of critical section */

        close(tmp_fd);

        return;

    }



    qemu_mutex_unlock(&cur_mon->mon_lock);

    error_setg(errp, QERR_FD_NOT_FOUND, fdname);

}
@@ -2242,6 +2253,7 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp) 
{

    mon_fd_t *monfd;



    qemu_mutex_lock(&mon->mon_lock);

    QLIST_FOREACH(monfd, &mon->fds, next) {

        int fd;
@@ -2255,10 +2267,12 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp) 
        QLIST_REMOVE(monfd, next);

        g_free(monfd->name);

        g_free(monfd);

        qemu_mutex_unlock(&mon->mon_lock);



        return fd;

    }



    qemu_mutex_unlock(&mon->mon_lock);

    error_setg(errp, "File descriptor named '%s' has not been found", fdname);

    return -1;

}