Btrfs: use dget_parent where we can UPDATED
There are lots of places where we do dentry->d_parent->d_inode without holding
the dentry->d_lock. This could cause problems with rename. So instead we need
to use dget_parent() and hold the reference to the parent as long as we are
going to use it's inode and then dput it at the end.
Signed-off-by: Josef Bacik <josef@redhat.com>
Cc: raven@themaw.net
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a29f193..054744a 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2869,6 +2869,7 @@
{
int ret = 0;
struct btrfs_root *root;
+ struct dentry *old_parent = NULL;
/*
* for regular files, if its inode is already on disk, we don't
@@ -2910,10 +2911,13 @@
if (IS_ROOT(parent))
break;
- parent = parent->d_parent;
+ parent = dget_parent(parent);
+ dput(old_parent);
+ old_parent = parent;
inode = parent->d_inode;
}
+ dput(old_parent);
out:
return ret;
}
@@ -2945,6 +2949,7 @@
{
int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
struct super_block *sb;
+ struct dentry *old_parent = NULL;
int ret = 0;
u64 last_committed = root->fs_info->last_trans_committed;
@@ -3016,10 +3021,13 @@
if (IS_ROOT(parent))
break;
- parent = parent->d_parent;
+ parent = dget_parent(parent);
+ dput(old_parent);
+ old_parent = parent;
}
ret = 0;
end_trans:
+ dput(old_parent);
if (ret < 0) {
BUG_ON(ret != -ENOSPC);
root->fs_info->last_trans_log_full_commit = trans->transid;
@@ -3039,8 +3047,13 @@
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct dentry *dentry)
{
- return btrfs_log_inode_parent(trans, root, dentry->d_inode,
- dentry->d_parent, 0);
+ struct dentry *parent = dget_parent(dentry);
+ int ret;
+
+ ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);
+ dput(parent);
+
+ return ret;
}
/*