| Message ID | 20190801165409.20121-4-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtiofsd: multithreading preparation part 3 | expand |
* Stefan Hajnoczi (stefanha@redhat.com) wrote: > Now that lo_destroy() is serialized we can call unref_inode() so that > all inode resources are freed. > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > contrib/virtiofsd/passthrough_ll.c | 43 ++++++++++++++---------------- > 1 file changed, 20 insertions(+), 23 deletions(-) > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > index a81c01d0d1..02a5e97326 100644 > --- a/contrib/virtiofsd/passthrough_ll.c > +++ b/contrib/virtiofsd/passthrough_ll.c > @@ -1340,28 +1340,6 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n) > } > } > > -static int unref_all_inodes_cb(gpointer key, gpointer value, > - gpointer user_data) > -{ > - struct lo_inode *inode = value; > - struct lo_data *lo = user_data; > - > - inode->nlookup = 0; > - lo_map_remove(&lo->ino_map, inode->fuse_ino); > - close(inode->fd); > - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ > - > - return TRUE; > -} > - > -static void unref_all_inodes(struct lo_data *lo) > -{ > - pthread_mutex_lock(&lo->mutex); > - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); > - pthread_mutex_unlock(&lo->mutex); > - > -} > - > static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) > { > struct lo_data *lo = lo_data(req); > @@ -2462,6 +2440,18 @@ static void lo_removemapping(fuse_req_t req, struct fuse_session *se, > fuse_reply_err(req, ret); > } > > +static int destroy_inode_cb(gpointer key, gpointer value, gpointer user_data) > +{ > + struct lo_inode *inode = value; > + struct lo_data *lo = user_data; > + > + /* inode->nlookup is normally protected by lo->mutex but see the > + * comment in lo_destroy(). > + */ > + unref_inode(lo, inode, inode->nlookup); > + return TRUE; > +} > + > static void lo_destroy(void *userdata, struct fuse_session *se) > { > struct lo_data *lo = (struct lo_data*) userdata; > @@ -2475,7 +2465,14 @@ static void lo_destroy(void *userdata, struct fuse_session *se) > fuse_err("%s: unmap during destroy failed\n", __func__); > } > } > - unref_all_inodes(lo); > + > + /* Normally lo->mutex must be taken when traversing lo->inodes but > + * lo_destroy() is a serialized request so no races are possible here. > + * > + * In addition, we cannot acquire lo->mutex since destroy_inode_cb() takes it > + * too and this would result in a recursive lock. > + */ > + g_hash_table_foreach_remove(lo->inodes, destroy_inode_cb, lo); > } > > static struct fuse_lowlevel_ops lo_oper = { > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
* Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > * Stefan Hajnoczi (stefanha@redhat.com) wrote: > > Now that lo_destroy() is serialized we can call unref_inode() so that > > all inode resources are freed. > > > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > > --- > > contrib/virtiofsd/passthrough_ll.c | 43 ++++++++++++++---------------- > > 1 file changed, 20 insertions(+), 23 deletions(-) > > > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > > index a81c01d0d1..02a5e97326 100644 > > --- a/contrib/virtiofsd/passthrough_ll.c > > +++ b/contrib/virtiofsd/passthrough_ll.c > > @@ -1340,28 +1340,6 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n) > > } > > } > > > > -static int unref_all_inodes_cb(gpointer key, gpointer value, > > - gpointer user_data) > > -{ > > - struct lo_inode *inode = value; > > - struct lo_data *lo = user_data; > > - > > - inode->nlookup = 0; > > - lo_map_remove(&lo->ino_map, inode->fuse_ino); > > - close(inode->fd); > > - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ > > - > > - return TRUE; > > -} > > - > > -static void unref_all_inodes(struct lo_data *lo) > > -{ > > - pthread_mutex_lock(&lo->mutex); > > - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); > > - pthread_mutex_unlock(&lo->mutex); > > - > > -} > > - > > static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) > > { > > struct lo_data *lo = lo_data(req); > > @@ -2462,6 +2440,18 @@ static void lo_removemapping(fuse_req_t req, struct fuse_session *se, > > fuse_reply_err(req, ret); > > } > > > > +static int destroy_inode_cb(gpointer key, gpointer value, gpointer user_data) > > +{ > > + struct lo_inode *inode = value; > > + struct lo_data *lo = user_data; > > + > > + /* inode->nlookup is normally protected by lo->mutex but see the > > + * comment in lo_destroy(). > > + */ > > + unref_inode(lo, inode, inode->nlookup); > > + return TRUE; > > +} > > + > > static void lo_destroy(void *userdata, struct fuse_session *se) > > { > > struct lo_data *lo = (struct lo_data*) userdata; > > @@ -2475,7 +2465,14 @@ static void lo_destroy(void *userdata, struct fuse_session *se) > > fuse_err("%s: unmap during destroy failed\n", __func__); > > } > > } > > - unref_all_inodes(lo); > > + > > + /* Normally lo->mutex must be taken when traversing lo->inodes but > > + * lo_destroy() is a serialized request so no races are possible here. > > + * > > + * In addition, we cannot acquire lo->mutex since destroy_inode_cb() takes it > > + * too and this would result in a recursive lock. > > + */ > > + g_hash_table_foreach_remove(lo->inodes, destroy_inode_cb, lo); I'm seeing a crash here if I ctrl-c the virtiofsd after it's got an active mount: (process:3219): GLib-CRITICAL **: 18:42:08.334: g_hash_table_foreach_remove_or_steal: assertion 'version == hash_table->version' failed (I only get the debug if I give seccomp both getpeername and ioctl; I think glib is trying to get to syslog and wants getpeername and I'm guessing ioctl to do something funky with the terminal). Dave > > } > > > > static struct fuse_lowlevel_ops lo_oper = { > > -- > > 2.21.0 > > > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
* Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > * Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > > * Stefan Hajnoczi (stefanha@redhat.com) wrote: > > > Now that lo_destroy() is serialized we can call unref_inode() so that > > > all inode resources are freed. > > > > > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > > > > --- > > > contrib/virtiofsd/passthrough_ll.c | 43 ++++++++++++++---------------- > > > 1 file changed, 20 insertions(+), 23 deletions(-) > > > > > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > > > index a81c01d0d1..02a5e97326 100644 > > > --- a/contrib/virtiofsd/passthrough_ll.c > > > +++ b/contrib/virtiofsd/passthrough_ll.c > > > @@ -1340,28 +1340,6 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n) > > > } > > > } > > > > > > -static int unref_all_inodes_cb(gpointer key, gpointer value, > > > - gpointer user_data) > > > -{ > > > - struct lo_inode *inode = value; > > > - struct lo_data *lo = user_data; > > > - > > > - inode->nlookup = 0; > > > - lo_map_remove(&lo->ino_map, inode->fuse_ino); > > > - close(inode->fd); > > > - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ > > > - > > > - return TRUE; > > > -} > > > - > > > -static void unref_all_inodes(struct lo_data *lo) > > > -{ > > > - pthread_mutex_lock(&lo->mutex); > > > - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); > > > - pthread_mutex_unlock(&lo->mutex); > > > - > > > -} > > > - > > > static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) > > > { > > > struct lo_data *lo = lo_data(req); > > > @@ -2462,6 +2440,18 @@ static void lo_removemapping(fuse_req_t req, struct fuse_session *se, > > > fuse_reply_err(req, ret); > > > } > > > > > > +static int destroy_inode_cb(gpointer key, gpointer value, gpointer user_data) > > > +{ > > > + struct lo_inode *inode = value; > > > + struct lo_data *lo = user_data; > > > + > > > + /* inode->nlookup is normally protected by lo->mutex but see the > > > + * comment in lo_destroy(). > > > + */ > > > + unref_inode(lo, inode, inode->nlookup); > > > + return TRUE; > > > +} > > > + > > > static void lo_destroy(void *userdata, struct fuse_session *se) > > > { > > > struct lo_data *lo = (struct lo_data*) userdata; > > > @@ -2475,7 +2465,14 @@ static void lo_destroy(void *userdata, struct fuse_session *se) > > > fuse_err("%s: unmap during destroy failed\n", __func__); > > > } > > > } > > > - unref_all_inodes(lo); > > > + > > > + /* Normally lo->mutex must be taken when traversing lo->inodes but > > > + * lo_destroy() is a serialized request so no races are possible here. > > > + * > > > + * In addition, we cannot acquire lo->mutex since destroy_inode_cb() takes it > > > + * too and this would result in a recursive lock. > > > + */ > > > + g_hash_table_foreach_remove(lo->inodes, destroy_inode_cb, lo); > > I'm seeing a crash here if I ctrl-c the virtiofsd after it's got an > active mount: > > (process:3219): GLib-CRITICAL **: 18:42:08.334: g_hash_table_foreach_remove_or_steal: assertion 'version == hash_table->version' failed > > (I only get the debug if I give seccomp both getpeername and ioctl; > I think glib is trying to get to syslog and wants getpeername > and I'm guessing ioctl to do something funky with the terminal). That's also the culprit for a crash on umount that only happens with -o cache=auto - reverting this makes it go away. Dave > Dave > > > > } > > > > > > static struct fuse_lowlevel_ops lo_oper = { > > > -- > > > 2.21.0 > > > > > -- > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On Mon, Aug 05, 2019 at 07:57:51PM +0100, Dr. David Alan Gilbert wrote: > * Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > > * Stefan Hajnoczi (stefanha@redhat.com) wrote: > > > Now that lo_destroy() is serialized we can call unref_inode() so that > > > all inode resources are freed. > > > > > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > > > > --- > > > contrib/virtiofsd/passthrough_ll.c | 43 ++++++++++++++---------------- > > > 1 file changed, 20 insertions(+), 23 deletions(-) > > > > > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > > > index a81c01d0d1..02a5e97326 100644 > > > --- a/contrib/virtiofsd/passthrough_ll.c > > > +++ b/contrib/virtiofsd/passthrough_ll.c > > > @@ -1340,28 +1340,6 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n) > > > } > > > } > > > > > > -static int unref_all_inodes_cb(gpointer key, gpointer value, > > > - gpointer user_data) > > > -{ > > > - struct lo_inode *inode = value; > > > - struct lo_data *lo = user_data; > > > - > > > - inode->nlookup = 0; > > > - lo_map_remove(&lo->ino_map, inode->fuse_ino); > > > - close(inode->fd); > > > - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ > > > - > > > - return TRUE; > > > -} > > > - > > > -static void unref_all_inodes(struct lo_data *lo) > > > -{ > > > - pthread_mutex_lock(&lo->mutex); > > > - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); > > > - pthread_mutex_unlock(&lo->mutex); > > > - > > > -} > > > - > > > static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) > > > { > > > struct lo_data *lo = lo_data(req); > > > @@ -2462,6 +2440,18 @@ static void lo_removemapping(fuse_req_t req, struct fuse_session *se, > > > fuse_reply_err(req, ret); > > > } > > > > > > +static int destroy_inode_cb(gpointer key, gpointer value, gpointer user_data) > > > +{ > > > + struct lo_inode *inode = value; > > > + struct lo_data *lo = user_data; > > > + > > > + /* inode->nlookup is normally protected by lo->mutex but see the > > > + * comment in lo_destroy(). > > > + */ > > > + unref_inode(lo, inode, inode->nlookup); > > > + return TRUE; > > > +} > > > + > > > static void lo_destroy(void *userdata, struct fuse_session *se) > > > { > > > struct lo_data *lo = (struct lo_data*) userdata; > > > @@ -2475,7 +2465,14 @@ static void lo_destroy(void *userdata, struct fuse_session *se) > > > fuse_err("%s: unmap during destroy failed\n", __func__); > > > } > > > } > > > - unref_all_inodes(lo); > > > + > > > + /* Normally lo->mutex must be taken when traversing lo->inodes but > > > + * lo_destroy() is a serialized request so no races are possible here. > > > + * > > > + * In addition, we cannot acquire lo->mutex since destroy_inode_cb() takes it > > > + * too and this would result in a recursive lock. > > > + */ > > > + g_hash_table_foreach_remove(lo->inodes, destroy_inode_cb, lo); > > I'm seeing a crash here if I ctrl-c the virtiofsd after it's got an > active mount: > > (process:3219): GLib-CRITICAL **: 18:42:08.334: g_hash_table_foreach_remove_or_steal: assertion 'version == hash_table->version' failed The hash table was modified by unref_inode() so g_hash_table_foreach_remove() panics. I'll come up with a different way of doing this. Stefan
diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c index a81c01d0d1..02a5e97326 100644 --- a/contrib/virtiofsd/passthrough_ll.c +++ b/contrib/virtiofsd/passthrough_ll.c @@ -1340,28 +1340,6 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n) } } -static int unref_all_inodes_cb(gpointer key, gpointer value, - gpointer user_data) -{ - struct lo_inode *inode = value; - struct lo_data *lo = user_data; - - inode->nlookup = 0; - lo_map_remove(&lo->ino_map, inode->fuse_ino); - close(inode->fd); - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ - - return TRUE; -} - -static void unref_all_inodes(struct lo_data *lo) -{ - pthread_mutex_lock(&lo->mutex); - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); - pthread_mutex_unlock(&lo->mutex); - -} - static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) { struct lo_data *lo = lo_data(req); @@ -2462,6 +2440,18 @@ static void lo_removemapping(fuse_req_t req, struct fuse_session *se, fuse_reply_err(req, ret); } +static int destroy_inode_cb(gpointer key, gpointer value, gpointer user_data) +{ + struct lo_inode *inode = value; + struct lo_data *lo = user_data; + + /* inode->nlookup is normally protected by lo->mutex but see the + * comment in lo_destroy(). + */ + unref_inode(lo, inode, inode->nlookup); + return TRUE; +} + static void lo_destroy(void *userdata, struct fuse_session *se) { struct lo_data *lo = (struct lo_data*) userdata; @@ -2475,7 +2465,14 @@ static void lo_destroy(void *userdata, struct fuse_session *se) fuse_err("%s: unmap during destroy failed\n", __func__); } } - unref_all_inodes(lo); + + /* Normally lo->mutex must be taken when traversing lo->inodes but + * lo_destroy() is a serialized request so no races are possible here. + * + * In addition, we cannot acquire lo->mutex since destroy_inode_cb() takes it + * too and this would result in a recursive lock. + */ + g_hash_table_foreach_remove(lo->inodes, destroy_inode_cb, lo); } static struct fuse_lowlevel_ops lo_oper = {
Now that lo_destroy() is serialized we can call unref_inode() so that all inode resources are freed. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- contrib/virtiofsd/passthrough_ll.c | 43 ++++++++++++++---------------- 1 file changed, 20 insertions(+), 23 deletions(-)