From 91dee39eebcfb47085c4d457a584b0e9723b6ca0 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Mon, 19 Apr 2010 10:15:44 -0700 Subject: [PATCH] ceph: fix snap realm splits The snap realm split was checking i_snap_realm, not the list_head, to determine if an inode belonged in the new realm. The check always failed, which meant we always moved the inode, corrupting the old realm's list and causing various crashes. Also wait to release old realm reference to avoid possibility of use after free. Signed-off-by: Sage Weil --- fs/ceph/snap.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 2b881262ef67..d5114db70453 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -869,16 +869,20 @@ skip_inode: continue; ci = ceph_inode(inode); spin_lock(&inode->i_lock); - if (!ci->i_snap_realm) - goto split_skip_inode; - ceph_put_snap_realm(mdsc, ci->i_snap_realm); - spin_lock(&realm->inodes_with_caps_lock); - list_add(&ci->i_snap_realm_item, - &realm->inodes_with_caps); - ci->i_snap_realm = realm; - spin_unlock(&realm->inodes_with_caps_lock); - ceph_get_snap_realm(mdsc, realm); -split_skip_inode: + if (list_empty(&ci->i_snap_realm_item)) { + struct ceph_snap_realm *oldrealm = + ci->i_snap_realm; + + dout(" moving %p to split realm %llx %p\n", + inode, realm->ino, realm); + spin_lock(&realm->inodes_with_caps_lock); + list_add(&ci->i_snap_realm_item, + &realm->inodes_with_caps); + ci->i_snap_realm = realm; + spin_unlock(&realm->inodes_with_caps_lock); + ceph_get_snap_realm(mdsc, realm); + ceph_put_snap_realm(mdsc, oldrealm); + } spin_unlock(&inode->i_lock); iput(inode); } -- 2.30.2