| Message ID | 20191212163904.159893-103-dgilbert@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | virtiofs daemon [all] | expand |
On 12/12/19 5:39 PM, Dr. David Alan Gilbert (git) wrote: > From: Stefan Hajnoczi <stefanha@redhat.com> > > 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> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > tools/virtiofsd/passthrough_ll.c | 41 ++++++++++++++++---------------- > 1 file changed, 20 insertions(+), 21 deletions(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c > index 1bf251a91d..38f4948e61 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -1355,26 +1355,6 @@ static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode *inode, > } > } > > -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); > @@ -2460,7 +2440,26 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence, > static void lo_destroy(void *userdata) > { > struct lo_data *lo = (struct lo_data *)userdata; > - 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 unref_inode() takes it > + * too and this would result in a recursive lock. > + */ > + while (true) { > + GHashTableIter iter; > + gpointer key, value; > + > + g_hash_table_iter_init(&iter, lo->inodes); > + if (!g_hash_table_iter_next(&iter, &key, &value)) { > + break; > + } > + > + struct lo_inode *inode = value; > + unref_inode_lolocked(lo, inode, inode->nlookup); > + } > } > > static struct fuse_lowlevel_ops lo_oper = { > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 1bf251a91d..38f4948e61 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1355,26 +1355,6 @@ static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode *inode, } } -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); @@ -2460,7 +2440,26 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence, static void lo_destroy(void *userdata) { struct lo_data *lo = (struct lo_data *)userdata; - 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 unref_inode() takes it + * too and this would result in a recursive lock. + */ + while (true) { + GHashTableIter iter; + gpointer key, value; + + g_hash_table_iter_init(&iter, lo->inodes); + if (!g_hash_table_iter_next(&iter, &key, &value)) { + break; + } + + struct lo_inode *inode = value; + unref_inode_lolocked(lo, inode, inode->nlookup); + } } static struct fuse_lowlevel_ops lo_oper = {