xfs: unregister inode shrinker before freeing filesystem structures
PATCH 1/1 xfs: unregister inode shrinker before freeing filesystem structures
From: Dave Chinner <[email protected]>
Currently we don't remove the XFS mount from the shrinker list until late in the unmount path. By this time, we have already torn down the internals of the filesystem (e.g. the per-ag structures), and hence if the shrinker is executed between the teardown and the unregistering, the shrinker will get NULL per-ag structure pointers and panic trying to dereference them.
Fix this by removingthe xfs mount from the shrinker list before tearing down it's internal structures.
--- fs/xfs/linux-2.6/xfs_super.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)
fs/xfs/linux-2.6/xfs_super.c +5 -1
@@ -1156,9 +1156,13 @@ xfs_fs_put_super(XFS_bflush (mp->m_ddev_targp); +/* +* Unregister the memory shrinker before we tear down the mount +* structure so we don't have memory reclaim racing with us here. +*/ +xfs_inode_shrinker_unregister (mp);xfs_unmountfs (mp);xfs_freesb (mp); -xfs_inode_shrinker_unregister (mp);xfs_icsb_destroy_counters (mp);xfs_close_devices (mp);xfs_free_fsname (mp);
Signature · 6 lines
1.7.1 _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs
Quoted 8 lines · Dave Chinner
From: Dave Chinner <[email protected]>
Currently we don't remove the XFS mount from the shrinker list until late in the unmount path. By this time, we have already torn down the internals of the filesystem (e.g. the per-ag structures), and hence if the shrinker is executed between the teardown and the unregistering, the shrinker will get NULL per-ag structure pointers and panic trying to dereference them.
Quoted 4 lines
Fix this by removingthe xfs mount from the shrinker list before tearing down it's internal structures.
Signed-off-by Dave Chinner <[email protected]>
Looks right to me, and is more symmetric with setup I think.
Quoted 13 lines
--- fs/xfs/linux-2.6/xfs_super.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)fs/xfs/linux-2.6/xfs_super.c +1
-0@@ -1156,9 +1156,13 @@ xfs_fs_put_super(XFS_bflush (mp->m_ddev_targp); +/*
fs/xfs/linux-2.6/xfs_super.c xfs_fs_put_super( · line 1168
Quoted 10 lines
fs/xfs/linux-2.6/xfs_super.c +4
-1+* Unregister the memory shrinker before we tear down the mount +* structure so we don't have memory reclaim racing with us here. +*/ +xfs_inode_shrinker_unregister (mp);xfs_unmountfs (mp);xfs_freesb (mp); -xfs_inode_shrinker_unregister (mp);xfs_icsb_destroy_counters (mp);xfs_close_devices (mp);xfs_free_fsname (mp);
_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs
Quoted 21 lines · Dave Chinner
From: Dave Chinner <[email protected]>
Currently we don't remove the XFS mount from the shrinker list until late in the unmount path. By this time, we have already torn down the internals of the filesystem (e.g. the per-ag structures), and hence if the shrinker is executed between the teardown and the unregistering, the shrinker will get NULL per-ag structure pointers and panic trying to dereference them.
Fix this by removingthe xfs mount from the shrinker list before tearing down it's internal structures.
Signed-off-by Dave Chinner <[email protected]>--- fs/xfs/linux-2.6/xfs_super.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)fs/xfs/linux-2.6/xfs_super.c +0
-0
fs/xfs/linux-2.6/xfs_super.c xfs_fs_put_super( · line 1163
Quoted 8 lines
fs/xfs/linux-2.6/xfs_super.c +5
-0@@ -1156,9 +1156,13 @@ xfs_fs_put_super(XFS_bflush (mp->m_ddev_targp); +/* +* Unregister the memory shrinker before we tear down the mount +* structure so we don't have memory reclaim racing with us here. +*/ +xfs_inode_shrinker_unregister (mp);
Given that we register the shrinker after syncd is started for we should also tear it down as the very first thing for symmetry resons.
_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs