From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: tytso@mit.edu, adilger.kernel@dilger.ca
Cc: linux-ext4@vger.kernel.org, linux-kernel <linux-kernel@vger.kernel.org>
Subject: [BUG] fs: ext4: possible ABBA deadlock in ext4_inline_data_truncate() and ext4_punch_hole()
Date: Thu, 9 Dec 2021 19:10:44 +0800 [thread overview]
Message-ID: <03a92134-ce74-f586-59a0-baed436b275a@gmail.com> (raw)
Hello,
My static analysis tool reports a possible ABBA deadlock in the ext4
module in Linux 5.10:
ext4_inline_data_truncate()
down_write(&EXT4_I(inode)->i_data_sem); --> Line 1895 (Lock A)
ext4_xattr_ibody_get()
ext4_xattr_inode_get()
ext4_xattr_inode_iget()
inode_lock(inode); --> Line 427 (Lock B)
ext4_punch_hole()
inode_lock(inode); --> Line 4018 (Lock B)
ext4_update_disksize_before_punch()
ext4_update_i_disksize()
down_write(&EXT4_I(inode)->i_data_sem); --> Line 3248 (Lock A)
When ext4_inline_data_truncate() and ext4_punch_hole() are concurrently
executed, the deadlock can occur.
I am not quite sure whether this possible deadlock is real and how to
fix it if it is real.
Any feedback would be appreciated, thanks :)
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Best wishes,
Jia-Ju Bai
next reply other threads:[~2021-12-09 11:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-09 11:10 Jia-Ju Bai [this message]
2021-12-09 17:00 ` Theodore Y. Ts'o
2021-12-10 2:03 ` Jia-Ju Bai
2021-12-10 18:05 ` Theodore Y. Ts'o
2021-12-12 12:56 ` Jia-Ju Bai
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