From 5ed91587e201c77b35a5555c8c082655bb5834fe Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Wed, 23 Feb 2022 09:04:56 +0800 Subject: [PATCH] ceph: do not release the global snaprealm until unmounting The global snaprealm would be created and then destroyed immediately every time when updating it. URL: https://tracker.ceph.com/issues/54362 Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov --- fs/ceph/mds_client.c | 2 +- fs/ceph/snap.c | 13 +++++++++++-- fs/ceph/super.h | 2 +- include/linux/ceph/ceph_fs.h | 3 ++- 4 files changed, 15 insertions(+), 5 deletions(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index ef91454..fa38c01 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4838,7 +4838,7 @@ void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc) mutex_unlock(&mdsc->mutex); ceph_cleanup_snapid_map(mdsc); - ceph_cleanup_empty_realms(mdsc); + ceph_cleanup_global_and_empty_realms(mdsc); cancel_work_sync(&mdsc->cap_reclaim_work); cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */ diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 66a1a92..cc9097c 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -121,7 +121,11 @@ static struct ceph_snap_realm *ceph_create_snap_realm( if (!realm) return ERR_PTR(-ENOMEM); - atomic_set(&realm->nref, 1); /* for caller */ + /* Do not release the global dummy snaprealm until unmouting */ + if (ino == CEPH_INO_GLOBAL_SNAPREALM) + atomic_set(&realm->nref, 2); + else + atomic_set(&realm->nref, 1); realm->ino = ino; INIT_LIST_HEAD(&realm->children); INIT_LIST_HEAD(&realm->child_item); @@ -261,9 +265,14 @@ static void __cleanup_empty_realms(struct ceph_mds_client *mdsc) spin_unlock(&mdsc->snap_empty_lock); } -void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc) +void ceph_cleanup_global_and_empty_realms(struct ceph_mds_client *mdsc) { + struct ceph_snap_realm *global_realm; + down_write(&mdsc->snap_rwsem); + global_realm = __lookup_snap_realm(mdsc, CEPH_INO_GLOBAL_SNAPREALM); + if (global_realm) + ceph_put_snap_realm(mdsc, global_realm); __cleanup_empty_realms(mdsc); up_write(&mdsc->snap_rwsem); } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index ef9f32e..0b4b519 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -940,7 +940,7 @@ extern void ceph_handle_snap(struct ceph_mds_client *mdsc, struct ceph_msg *msg); extern int __ceph_finish_cap_snap(struct ceph_inode_info *ci, struct ceph_cap_snap *capsnap); -extern void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc); +extern void ceph_cleanup_global_and_empty_realms(struct ceph_mds_client *mdsc); extern struct ceph_snapid_map *ceph_get_snapid_map(struct ceph_mds_client *mdsc, u64 snap); diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h index f14f9bc..86bf82d 100644 --- a/include/linux/ceph/ceph_fs.h +++ b/include/linux/ceph/ceph_fs.h @@ -28,7 +28,8 @@ #define CEPH_INO_ROOT 1 -#define CEPH_INO_CEPH 2 /* hidden .ceph dir */ +#define CEPH_INO_CEPH 2 /* hidden .ceph dir */ +#define CEPH_INO_GLOBAL_SNAPREALM 3 /* global dummy snaprealm */ /* arbitrary limit on max # of monitors (cluster of 3 is typical) */ #define CEPH_MAX_MON 31 -- 2.7.4