From 6f12a5767f6912f6913cd9dfa4c6a5484a766000 Mon Sep 17 00:00:00 2001 From: Soumya Koduri Date: Mon, 8 Feb 2016 22:33:56 +0530 Subject: gfapi: Use inode_forget in case of handle objects Currently with gfapi, even if applications release their reference on paritular inode entries, those entries never get destroyed as they shall always have positive nlookup count unless inode_table exceeds lru limit. Since inodes and their contexts can consume considerable amount of memory, applications may end up consuming lot of memory and may even get OOM killed. To avoid that, have considered below approaches (for handle based access)- a) Do 'inode_lookup' only if the corresponding inode is created for the first time and forget it during close of the handle This shall not work as multiple handle objects can refer to same inode entry and inode_forget from second handle object onwards shall result in assert. b) Do 'inode_lookup' during a handle or fd creation But this approach shall affect the performance of the fops which operate on neither handle nor fd. c) current approach taken- Applications using glfs handle objects hold a reference on corresponding inode entries. Hence it is safe to forget those inodes and make nlookup count to '0' while trying to delete those handle objects. That way the last unref (i.e, from the last handle close) shall result in inode_destroy(). This is backport of the below patch - http://review.gluster.org/13096 Change-Id: Id2c7ab178894a10c0030c143ba71e7813df8d18c Signed-off-by: Soumya Koduri BUG: 1311441 Reviewed-on: http://review.gluster.org/13096 Reviewed-by: jiffin tony Thottan Reviewed-by: Niels de Vos Reviewed-by: Kaleb KEITHLEY Reviewed-on: http://review.gluster.org/13506 Smoke: Gluster Build System NetBSD-regression: NetBSD Build System CentOS-regression: Gluster Build System --- api/src/glfs-handleops.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'api') diff --git a/api/src/glfs-handleops.c b/api/src/glfs-handleops.c index bc57221055f..cd0f6b3e950 100644 --- a/api/src/glfs-handleops.c +++ b/api/src/glfs-handleops.c @@ -1370,6 +1370,9 @@ GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_h_create_from_handle, 3.4.2); int pub_glfs_h_close (struct glfs_object *object) { + /* since glfs_h_* objects hold a reference to inode + * it is safe to keep lookup count to '0' */ + inode_forget (object->inode, 0); inode_unref (object->inode); GF_FREE (object); -- cgit