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authorSage Weil <sage@newdream.net>2010-04-19 10:15:44 -0700
committerSage Weil <sage@newdream.net>2010-05-03 10:49:23 -0700
commit91dee39eebcfb47085c4d457a584b0e9723b6ca0 (patch)
tree52bdeb4795c3b60b1d23460cada8c813c94fb7a9 /fs/ceph
parentc10f5e12bafde7f7a2f9b75d76f7a68d62154e91 (diff)
downloadop-kernel-dev-91dee39eebcfb47085c4d457a584b0e9723b6ca0.zip
op-kernel-dev-91dee39eebcfb47085c4d457a584b0e9723b6ca0.tar.gz
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 <sage@newdream.net>
Diffstat (limited to 'fs/ceph')
-rw-r--r--fs/ceph/snap.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 2b88126..d5114db 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);
}
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