From: Wen Yang <wenyang@linux.alibaba.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>
Cc: Xunlei Pang <xlpang@linux.alibaba.com>,
linux-kernel@vger.kernel.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
stable@vger.kernel.org, Wen Yang <wenyang@linux.alibaba.com>
Subject: [PATCH v2 4.9 08/10] proc: Clear the pieces of proc_inode that proc_evict_inode cares about
Date: Thu, 7 Jan 2021 15:52:20 +0800 [thread overview]
Message-ID: <20210107075222.62623-9-wenyang@linux.alibaba.com> (raw)
In-Reply-To: <20210107075222.62623-1-wenyang@linux.alibaba.com>
From: "Eric W. Biederman" <ebiederm@xmission.com>
[ Upstream commit 71448011ea2a1cd36d8f5cbdab0ed716c454d565 ]
This just keeps everything tidier, and allows for using flags like
SLAB_TYPESAFE_BY_RCU where slabs are not always cleared before reuse.
I don't see reuse without reinitializing happening with the proc_inode
but I had a false alarm while reworking flushing of proc dentries and
indoes when a process dies that caused me to tidy this up.
The code is a little easier to follow and reason about this
way so I figured the changes might as well be kept.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
---
fs/proc/inode.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 920c761..739fb9c 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -32,21 +32,27 @@ static void proc_evict_inode(struct inode *inode)
{
struct proc_dir_entry *de;
struct ctl_table_header *head;
+ struct proc_inode *ei = PROC_I(inode);
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
/* Stop tracking associated processes */
- put_pid(PROC_I(inode)->pid);
+ if (ei->pid) {
+ put_pid(ei->pid);
+ ei->pid = NULL;
+ }
/* Let go of any associated proc directory entry */
- de = PDE(inode);
- if (de)
+ de = ei->pde;
+ if (de) {
pde_put(de);
+ ei->pde = NULL;
+ }
- head = PROC_I(inode)->sysctl;
+ head = ei->sysctl;
if (head) {
- RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
+ RCU_INIT_POINTER(ei->sysctl, NULL);
proc_sys_evict_inode(inode, head);
}
}
--
1.8.3.1
next prev parent reply other threads:[~2021-01-07 7:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-07 7:52 [PATCH v2 4.9 00/10] fix a race in release_task when flushing the dentry Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 01/10] clone: add CLONE_PIDFD Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 02/10] pidfd: add polling support Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 03/10] proc: Pass file mode to proc_pid_make_inode Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 04/10] proc: Better ownership of files for non-dumpable tasks in user namespaces Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 05/10] proc: use %u for pid printing and slightly less stack Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 06/10] proc: Rename in proc_inode rename sysctl_inodes sibling_inodes Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 07/10] proc: Generalize proc_sys_prune_dcache into proc_prune_siblings_dcache Wen Yang
2021-01-07 7:52 ` Wen Yang [this message]
2021-01-07 7:52 ` [PATCH v2 4.9 09/10] proc: Use d_invalidate in proc_prune_siblings_dcache Wen Yang
2021-01-07 7:52 ` [PATCH v2 4.9 10/10] proc: Use a list of inodes to flush from proc Wen Yang
2021-01-07 12:17 ` [PATCH v2 4.9 00/10] fix a race in release_task when flushing the dentry Greg Kroah-Hartman
2021-01-07 16:21 ` Wen Yang
2021-01-07 18:28 ` Greg Kroah-Hartman
2021-01-08 2:42 ` Wen Yang
2021-01-09 12:36 ` Greg Kroah-Hartman
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