linux-kernel - [PATCH 5/6] fs: allow pagefault based writers to be frozen

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250401-work-freeze-v1-5-d000611d4ab0@kernel.org>
Date: Tue,  1 Apr 2025 02:32:50 +0200
From: Christian Brauner <brauner@...nel.org>
To: linux-fsdevel@...r.kernel.org,
	jack@...e.cz
Cc: Christian Brauner <brauner@...nel.org>,
	Ard Biesheuvel <ardb@...nel.org>,
	linux-efi@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	James Bottomley <James.Bottomley@...senpartnership.com>,
	mcgrof@...nel.org,
	hch@...radead.org,
	david@...morbit.com,
	rafael@...nel.org,
	djwong@...nel.org,
	pavel@...nel.org,
	peterz@...radead.org,
	mingo@...hat.com,
	will@...nel.org,
	boqun.feng@...il.com
Subject: [PATCH 5/6] fs: allow pagefault based writers to be frozen

Otherwise tasks such as systemd-journald that mmap a file and write to
it will not be frozen after we've frozen the filesystem.

Signed-off-by: Christian Brauner <brauner@...nel.org>
---
 include/linux/fs.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index b379a46b5576..528e73f192ac 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1782,7 +1782,8 @@ static inline void __sb_end_write(struct super_block *sb, int level)
 static inline void __sb_start_write(struct super_block *sb, int level)
 {
 	percpu_down_read_freezable(sb->s_writers.rw_sem + level - 1,
-				   level == SB_FREEZE_WRITE);
+				   (level == SB_FREEZE_WRITE ||
+				    level == SB_FREEZE_PAGEFAULT));
 }
 
 static inline bool __sb_start_write_trylock(struct super_block *sb, int level)

-- 
2.47.2