On Sun, May 26, 2013 at 09:50:27PM +0800, Liu Bo wrote: > Commit be283b2e674a09457d4563729015adb637ce7cc1 > ( Btrfs: use helper to cleanup tree roots) introduced the following bug,
Well, it did not introduce the bug, but made it visible. > We've free'ed commit_root before actually getting to free block groups where > caching thread needs valid extent_root->commit_root. > > Signed-off-by: Liu Bo <bo.li....@oracle.com> > --- > fs/btrfs/disk-io.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index e7b3cb5..a5c8f28 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -3512,10 +3512,10 @@ int close_ctree(struct btrfs_root *root) > percpu_counter_sum(&fs_info->delalloc_bytes)); > } > > - free_root_pointers(fs_info, 1); > - > btrfs_free_block_groups(fs_info); > > + free_root_pointers(fs_info, 1); > + > del_fs_roots(fs_info); > > iput(fs_info->btree_inode); This makes it just harder to hit, but the worker threads that get stopped after iput may still access the freed roots, like mentioned here http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg24239.html david -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
