blob: 4420f6b0f2b5f9b83fed7f117ba2bc3a92d8d146 [file] [log] [blame]
From e100b9b1b6cf52334b8630a29050f9bbd6b4e6d1 Mon Sep 17 00:00:00 2001
From: Filipe Manana <>
Date: Tue, 10 Mar 2020 12:13:53 +0000
Subject: [PATCH] btrfs: fix log context list corruption after rename whiteout
commit 236ebc20d9afc5e9ff52f3cf3f365a91583aac10 upstream.
During a rename whiteout, if btrfs_whiteout_for_rename() returns an error
we can end up returning from btrfs_rename() with the log context object
still in the root's log context list - this happens if 'sync_log' was
set to true before we called btrfs_whiteout_for_rename() and it is
dangerous because we end up with a corrupt linked list (root->log_ctxs)
as the log context object was allocated on the stack.
After btrfs_rename() returns, any task that is running btrfs_sync_log()
concurrently can end up crashing because that linked list is traversed by
btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in
the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list
corruption after rename exchange operation") fixed.
Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name")
CC: # 4.19+
Signed-off-by: Filipe Manana <>
Signed-off-by: David Sterba <>
Signed-off-by: Paul Gortmaker <>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ac6698bcd8ae..cba20e93d050 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10100,6 +10100,10 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root, &ctx);
if (ret)
commit_transaction = true;
+ } else if (sync_log) {
+ mutex_lock(&root->log_mutex);
+ list_del(&ctx.list);
+ mutex_unlock(&root->log_mutex);
if (commit_transaction) {
ret = btrfs_commit_transaction(trans);