diff options
| -rw-r--r-- | fs/btrfs/inode.c | 36 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.c | 33 |
2 files changed, 36 insertions, 33 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a3c6e76f5a4e..6dd6e50d143a 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -5181,6 +5181,42 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) iput(inode); inode = ERR_PTR(ret); } + /* + * If orphan cleanup did remove any orphans, it means the tree + * was modified and therefore the commit root is not the same as + * the current root anymore. This is a problem, because send + * uses the commit root and therefore can see inode items that + * don't exist in the current root anymore, and for example make + * calls to btrfs_iget, which will do tree lookups based on the + * current root and not on the commit root. Those lookups will + * fail, returning a -ESTALE error, and making send fail with + * that error. So make sure a send does not see any orphans we + * have just removed, and that it will see the same inodes + * regardless of whether a transaction commit happened before + * it started (meaning that the commit root will be the same as + * the current root) or not. + */ + if (sub_root->node != sub_root->commit_root) { + u64 sub_flags = btrfs_root_flags(&sub_root->root_item); + + if (sub_flags & BTRFS_ROOT_SUBVOL_RDONLY) { + struct extent_buffer *eb; + + /* + * Assert we can't have races between dentry + * lookup called through the snapshot creation + * ioctl and the VFS. + */ + ASSERT(mutex_is_locked(&dir->i_mutex)); + + down_write(&root->fs_info->commit_root_sem); + eb = sub_root->commit_root; + sub_root->commit_root = + btrfs_root_node(sub_root); + up_write(&root->fs_info->commit_root_sem); + free_extent_buffer(eb); + } + } } return inode; diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 47aceb494d1d..845287ca59c3 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -711,39 +711,6 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, if (ret) goto fail; - ret = btrfs_orphan_cleanup(pending_snapshot->snap); - if (ret) - goto fail; - - /* - * If orphan cleanup did remove any orphans, it means the tree was - * modified and therefore the commit root is not the same as the - * current root anymore. This is a problem, because send uses the - * commit root and therefore can see inode items that don't exist - * in the current root anymore, and for example make calls to - * btrfs_iget, which will do tree lookups based on the current root - * and not on the commit root. Those lookups will fail, returning a - * -ESTALE error, and making send fail with that error. So make sure - * a send does not see any orphans we have just removed, and that it - * will see the same inodes regardless of whether a transaction - * commit happened before it started (meaning that the commit root - * will be the same as the current root) or not. - */ - if (readonly && pending_snapshot->snap->node != - pending_snapshot->snap->commit_root) { - trans = btrfs_join_transaction(pending_snapshot->snap); - if (IS_ERR(trans) && PTR_ERR(trans) != -ENOENT) { - ret = PTR_ERR(trans); - goto fail; - } - if (!IS_ERR(trans)) { - ret = btrfs_commit_transaction(trans, - pending_snapshot->snap); - if (ret) - goto fail; - } - } - inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry); if (IS_ERR(inode)) { ret = PTR_ERR(inode); |