ext4: check and assert if marking an no_delete evicting inode dirty
authorZhang Yi <yi.zhang@huawei.com>
Wed, 29 Jun 2022 11:26:47 +0000 (19:26 +0800)
committerTheodore Ts'o <tytso@mit.edu>
Tue, 29 Nov 2022 21:10:27 +0000 (16:10 -0500)
commit318cdc822c63b6e2befcfdc2088378ae6fa18def
treeab53a8d1f807b12a2c4f5c975dfb8481edb6d703
parentbc12ac98ea2e1b70adc6478c8b473a0003b659d3
ext4: check and assert if marking an no_delete evicting inode dirty

In ext4_evict_inode(), if we evicting an inode in the 'no_delete' path,
it cannot be raced by another mark_inode_dirty(). If it happens,
someone else may accidentally dirty it without holding inode refcount
and probably cause use-after-free issues in the writeback procedure.
It's indiscoverable and hard to debug, so add an WARN_ON_ONCE() to
check and detect this issue in advance.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220629112647.4141034-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
fs/ext4/inode.c