From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
To: "Darrick J. Wong" <djwong@kernel.org>,
linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: yuanxzhang@fudan.edu.cn, Xiyu Yang <xiyuyang19@fudan.edu.cn>,
Xin Tan <tanxin.ctf@gmail.com>
Subject: [PATCH] xfs: Convert from atomic_t to refcount_t on xlog_ticket->t_ref
Date: Sat, 17 Jul 2021 18:21:02 +0800 [thread overview]
Message-ID: <1626517262-42986-1-git-send-email-xiyuyang19@fudan.edu.cn> (raw)
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
fs/xfs/xfs_log.c | 10 +++++-----
fs/xfs/xfs_log_priv.h | 4 +++-
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 36fa2650b081..1da711f1a229 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3347,8 +3347,8 @@ void
xfs_log_ticket_put(
xlog_ticket_t *ticket)
{
- ASSERT(atomic_read(&ticket->t_ref) > 0);
- if (atomic_dec_and_test(&ticket->t_ref))
+ ASSERT(refcount_read(&ticket->t_ref) > 0);
+ if (refcount_dec_and_test(&ticket->t_ref))
kmem_cache_free(xfs_log_ticket_zone, ticket);
}
@@ -3356,8 +3356,8 @@ xlog_ticket_t *
xfs_log_ticket_get(
xlog_ticket_t *ticket)
{
- ASSERT(atomic_read(&ticket->t_ref) > 0);
- atomic_inc(&ticket->t_ref);
+ ASSERT(refcount_read(&ticket->t_ref) > 0);
+ refcount_inc(&ticket->t_ref);
return ticket;
}
@@ -3477,7 +3477,7 @@ xlog_ticket_alloc(
unit_res = xlog_calc_unit_res(log, unit_bytes);
- atomic_set(&tic->t_ref, 1);
+ refcount_set(&tic->t_ref, 1);
tic->t_task = current;
INIT_LIST_HEAD(&tic->t_queue);
tic->t_unit_res = unit_res;
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 4c41bbfa33b0..c4157d87cea4 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -6,6 +6,8 @@
#ifndef __XFS_LOG_PRIV_H__
#define __XFS_LOG_PRIV_H__
+#include <linux/refcount.h>
+
struct xfs_buf;
struct xlog;
struct xlog_ticket;
@@ -163,7 +165,7 @@ typedef struct xlog_ticket {
struct list_head t_queue; /* reserve/write queue */
struct task_struct *t_task; /* task that owns this ticket */
xlog_tid_t t_tid; /* transaction identifier : 4 */
- atomic_t t_ref; /* ticket reference count : 4 */
+ refcount_t t_ref; /* ticket reference count : 4 */
int t_curr_res; /* current reservation in bytes : 4 */
int t_unit_res; /* unit reservation in bytes : 4 */
char t_ocnt; /* original count : 1 */
--
2.7.4
next reply other threads:[~2021-07-17 10:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-17 10:21 Xiyu Yang [this message]
2021-07-20 2:20 ` [PATCH] xfs: Convert from atomic_t to refcount_t on xlog_ticket->t_ref Darrick J. Wong
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