diff mbox series

[12/44] btrfs: hold a root ref in btrfs_get_dentry

Message ID	20191206144538.168112-13-josef@toxicpanda.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=lvGj=Z4=vger.kernel.org=linux-btrfs-owner@kernel.org> From: Josef Bacik <josef@toxicpanda.com> To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 12/44] btrfs: hold a root ref in btrfs_get_dentry Date: Fri, 6 Dec 2019 09:45:06 -0500 Message-Id: <20191206144538.168112-13-josef@toxicpanda.com> In-Reply-To: <20191206144538.168112-1-josef@toxicpanda.com> References: <20191206144538.168112-1-josef@toxicpanda.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk
Series	Cleanup how we handle root refs, part 1 \| expand [0/44] Cleanup how we handle root refs, part 1 [01/44] btrfs: push __setup_root into btrfs_alloc_root [02/44] btrfs: move fs root init stuff into btrfs_init_fs_root [03/44] btrfs: make btrfs_find_orphan_roots use btrfs_get_fs_root [04/44] btrfs: export and use btrfs_read_tree_root [05/44] btrfs: make relocation use btrfs_read_tree_root() [06/44] btrfs: kill btrfs_read_fs_root [07/44] btrfs: kill the btrfs_read_fs_root_no_name helper [08/44] btrfs: make the fs root init functions static [09/44] btrfs: handle NULL roots in btrfs_put_fs_root() [10/44] btrfs: hold a ref on fs roots while they're in the radix tree [11/44] btrfs: hold a ref on the root in resolve_indirect_ref [12/44] btrfs: hold a root ref in btrfs_get_dentry [13/44] btrfs: hold a ref on the root in __btrfs_run_defrag_inode [14/44] btrfs: hold a ref for the root in record_one_backref [15/44] btrfs: grab a ref on the root in relink_extent_backref [16/44] btrfs: hold a ref on the root in fixup_tree_root_location [17/44] btrfs: hold a ref on the root in create_subvol [18/44] btrfs: hold a ref on the root in search_ioctl [19/44] btrfs: hold a ref on the root in btrfs_search_path_in_tree [20/44] btrfs: hold a ref on the root in btrfs_search_path_in_tree_user [21/44] btrfs: hold a ref on the root in btrfs_ioctl_get_subvol_info [22/44] btrfs: hold ref on root in btrfs_ioctl_default_subvol [23/44] btrfs: hold a ref on the root in build_backref_tree [24/44] btrfs: hold a ref on the root in prepare_to_merge [25/44] btrfs: hold a ref on the root in merge_reloc_roots [26/44] btrfs: hold a ref on the root in record_reloc_root_in_trans [27/44] btrfs: hold a ref on the root in find_data_references [28/44] btrfs: hold a ref on the root in create_reloc_inode [29/44] btrfs: hold a ref on the root in btrfs_recover_relocation [30/44] btrfs: push grab_fs_root into read_fs_root [31/44] btrfs: hold a ref for the root in btrfs_find_orphan_roots [32/44] btrfs: hold a ref on the root in scrub_print_warning_inode [33/44] btrfs: hold a ref on the root in btrfs_ioctl_send [34/44] btrfs: hold a ref on the root in get_subvol_name_from_objectid [35/44] btrfs: hold a ref on the root in create_pending_snapshot [36/44] btrfs: hold a ref on the root in btrfs_recover_log_trees [37/44] btrfs: hold a ref on the root in btrfs_check_uuid_tree_entry [38/44] btrfs: hold a ref on the root in open_ctree [39/44] btrfs: use btrfs_put_fs_root to free roots always [40/44] btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root [41/44] btrfs: free more things in btrfs_free_fs_info [42/44] btrfs: move fs_info init work into it's own helper function [43/44] btrfs: add a leak check for roots [44/44] btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root

Commit Message

Josef Bacik Dec. 6, 2019, 2:45 p.m. UTC

Looking up the inode we need to search the root, make sure we hold a
reference on that root while we're doing the lookup.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/export.c | 5 +++++
 1 file changed, 5 insertions(+)

diff mbox series

Patch

diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 08cd8c4a02a5..eba6c6d27bad 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -82,12 +82,17 @@  static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 		err = PTR_ERR(root);
 		goto fail;
 	}
+	if (!btrfs_grab_fs_root(root)) {
+		err = -ENOENT;
+		goto fail;
+	}
 
 	key.objectid = objectid;
 	key.type = BTRFS_INODE_ITEM_KEY;
 	key.offset = 0;
 
 	inode = btrfs_iget(sb, &key, root);
+	btrfs_put_fs_root(root);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
 		goto fail;