From: Kirill Tkhai <tkhai@xxxxx>
xfs_fs_nr_cached_objects() touches sb->s_fs_info,
and this patch makes it to be destructed later.
After this patch xfs_fs_nr_cached_objects() is safe
for splitting unregister_shrinker(): mp->m_perag_tree
is stable till destroy_super_work(), while iteration
over it is already RCU-protected by internal XFS
business.
Signed-off-by: Kirill Tkhai <tkhai@xxxxx>
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
fs/xfs/xfs_super.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 7e706255f165..694616524c76 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -743,11 +743,18 @@ xfs_fs_drop_inode(
}
static void
-xfs_mount_free(
+xfs_free_names(
struct xfs_mount *mp)
{
kfree(mp->m_rtname);
kfree(mp->m_logname);
+}
+
+static void
+xfs_mount_free(
+ struct xfs_mount *mp)
+{
+ xfs_free_names(mp);
kmem_free(mp);
}
@@ -1136,8 +1143,19 @@ xfs_fs_put_super(
xfs_destroy_mount_workqueues(mp);
xfs_close_devices(mp);
- sb->s_fs_info = NULL;
- xfs_mount_free(mp);
+ xfs_free_names(mp);
+}
+
+static void
+xfs_fs_destroy_super(
+ struct super_block *sb)
+{
+ if (sb->s_fs_info) {
+ struct xfs_mount *mp = XFS_M(sb);
+
+ kmem_free(mp);
+ sb->s_fs_info = NULL;
+ }
}
static long
@@ -1165,6 +1183,7 @@ static const struct super_operations xfs_super_operations = {
.dirty_inode = xfs_fs_dirty_inode,
.drop_inode = xfs_fs_drop_inode,
.put_super = xfs_fs_put_super,
+ .destroy_super = xfs_fs_destroy_super,
.sync_fs = xfs_fs_sync_fs,
.freeze_fs = xfs_fs_freeze,
.unfreeze_fs = xfs_fs_unfreeze,
--
2.30.2
