From: Christoph Hellwig <hch@lst.de>
To: Christian Brauner <brauner@kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>
Cc: Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>,
Tejun Heo <tj@kernel.org>,
Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna@kernel.org>,
Kees Cook <keescook@chromium.org>,
Damien Le Moal <dlemoal@kernel.org>,
Naohiro Aota <naohiro.aota@wdc.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-nfs@vger.kernel.org, linux-hardening@vger.kernel.org,
cgroups@vger.kernel.org
Subject: [PATCH 16/19] x86/resctrl: release rdtgroup_mutex and the CPU hotplug lock in rdt_shutdown_sb
Date: Wed, 13 Sep 2023 08:10:10 -0300 [thread overview]
Message-ID: <20230913111013.77623-17-hch@lst.de> (raw)
In-Reply-To: <20230913111013.77623-1-hch@lst.de>
While the resctl code is a bit confusing, I can't find anything protected
by rdtgroup_mutex or the CPU hotplug lock in generic_shutdown_super or
kernfs_free_sb. Drop the locks at the end of rdt_shutdown_sb to avoid
holding locks over method calls and VFS code which itself already has a
rather complicated locking hierarchy.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 8db767fd80df6b..e87de519493021 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2793,11 +2793,6 @@ static void rdt_shutdown_sb(struct super_block *sb)
static_branch_disable_cpuslocked(&rdt_mon_enable_key);
static_branch_disable_cpuslocked(&rdt_enable_key);
kernfs_shutdown_sb(sb);
-}
-
-static void rdt_free_sb(struct super_block *sb)
-{
- kernfs_free_sb(sb);
mutex_unlock(&rdtgroup_mutex);
cpus_read_unlock();
}
@@ -2807,7 +2802,7 @@ static struct file_system_type rdt_fs_type = {
.init_fs_context = rdt_init_fs_context,
.parameters = rdt_fs_parameters,
.shutdown_sb = rdt_shutdown_sb,
- .free_sb = rdt_free_sb,
+ .free_sb = kernfs_free_sb,
};
static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
--
2.39.2
next prev parent reply other threads:[~2023-09-13 11:12 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 11:09 split up ->kill_sb Christoph Hellwig
2023-09-13 11:09 ` [PATCH 01/19] fs: reflow deactivate_locked_super Christoph Hellwig
2023-09-13 16:35 ` Christian Brauner
2023-09-26 9:24 ` Christoph Hellwig
2023-09-13 11:09 ` [PATCH 02/19] fs: make ->kill_sb optional Christoph Hellwig
2023-09-13 11:09 ` [PATCH 03/19] fs: release anon dev_t in deactivate_locked_super Christoph Hellwig
2023-09-13 23:27 ` Al Viro
2023-09-14 2:37 ` Al Viro
2023-09-14 5:38 ` Al Viro
2023-09-14 7:56 ` Christian Brauner
2023-09-26 9:31 ` Christoph Hellwig
2023-09-14 14:02 ` Christian Brauner
2023-09-14 16:58 ` Al Viro
2023-09-14 19:23 ` Al Viro
2023-09-15 7:40 ` Christian Brauner
2023-09-15 9:44 ` Christian Brauner
2023-09-15 14:12 ` Christian Brauner
2023-09-15 14:28 ` Al Viro
2023-09-15 14:33 ` Al Viro
2023-09-15 14:40 ` Christian Brauner
2023-09-26 9:41 ` Christoph Hellwig
2023-09-26 9:38 ` Christoph Hellwig
2023-09-26 21:25 ` Al Viro
2023-09-27 22:29 ` Al Viro
2023-10-02 6:46 ` Christoph Hellwig
2023-10-09 21:57 ` Al Viro
2023-10-10 8:44 ` Christian Brauner
2023-10-17 19:50 ` Al Viro
2023-09-13 11:09 ` [PATCH 04/19] NFS: remove the s_dev field from struct nfs_server Christoph Hellwig
2023-09-13 11:09 ` [PATCH 05/19] fs: assign an anon dev_t in common code Christoph Hellwig
2023-09-14 0:34 ` Al Viro
2023-09-13 11:10 ` [PATCH 06/19] qibfs: use simple_release_fs Christoph Hellwig
2023-09-18 11:41 ` Leon Romanovsky
2023-09-13 11:10 ` [PATCH 07/19] hypfs: use d_genocide to kill fs entries Christoph Hellwig
2023-09-13 11:10 ` [PATCH 08/19] pstore: shrink the pstore_sb_lock critical section in pstore_kill_sb Christoph Hellwig
2023-09-13 22:07 ` Kees Cook
2023-09-13 11:10 ` [PATCH 09/19] zonefs: remove duplicate cleanup in zonefs_fill_super Christoph Hellwig
2023-09-14 0:33 ` Damien Le Moal
2023-09-14 0:49 ` Al Viro
2023-09-13 11:10 ` [PATCH 10/19] USB: gadget/legacy: remove sb_mutex Christoph Hellwig
2023-09-13 16:10 ` Alan Stern
2023-09-26 9:24 ` Christoph Hellwig
2023-09-14 10:22 ` Sergey Shtylyov
2023-09-13 11:10 ` [PATCH 11/19] fs: add new shutdown_sb and free_sb methods Christoph Hellwig
2023-09-14 2:07 ` Al Viro
2023-09-13 11:10 ` [PATCH 12/19] fs: convert kill_litter_super to litter_shutdown_sb Christoph Hellwig
2023-09-13 22:07 ` Kees Cook
2023-09-13 11:10 ` [PATCH 13/19] fs: convert kill_block_super to block_free_sb Christoph Hellwig
2023-09-14 2:29 ` Al Viro
2023-09-13 11:10 ` [PATCH 14/19] jffs2: convert to ->shutdown_sb and ->free_sb Christoph Hellwig
2023-09-13 11:10 ` [PATCH 15/19] kernfs: split ->kill_sb Christoph Hellwig
2023-09-18 15:24 ` Michal Koutný
2023-09-13 11:10 ` Christoph Hellwig [this message]
2023-09-13 11:10 ` [PATCH 17/19] NFS: move nfs_kill_super to fs_context.c Christoph Hellwig
2023-09-13 11:10 ` [PATCH 18/19] fs: simple ->shutdown_sb and ->free_sb conversions Christoph Hellwig
2023-09-13 11:10 ` [PATCH 19/19] fs: remove ->kill_sb Christoph Hellwig
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