From: Amol Grover <frextrite@gmail.com>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
target-devel@vger.kernel.org,
Joel Fernandes <joel@joelfernandes.org>,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: [Linux-kernel-mentees] [PATCH v2 2/3] drivers: target: target_core_tpg: Pass lockdep expression to RCU lists
Date: Fri, 10 Jan 2020 22:35:58 +0530 [thread overview]
Message-ID: <20200110170558.23466-2-frextrite@gmail.com> (raw)
In-Reply-To: <20200110170558.23466-1-frextrite@gmail.com>
tpg->tpg_lun_hlist is traversed with hlist_for_each_entry_rcu
outside an RCU read-side critical section but under the
protection of tpg->tpg_lun_mutex.
Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and
harden RCU lists.
Add macro for the corresponding lockdep expression to make the code
clean and concise.
Signed-off-by: Amol Grover <frextrite@gmail.com>
---
drivers/target/target_core_tpg.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index d24e0a3ba3ff..0d89b738ca6e 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -30,6 +30,9 @@
#include "target_core_pr.h"
#include "target_core_ua.h"
+#define tpg_lun_mutex_held() \
+ lockdep_is_held(&tpg->tpg_lun_mutex)
+
extern struct se_device *g_lun0_dev;
/* __core_tpg_get_initiator_node_acl():
@@ -110,12 +113,12 @@ void core_tpg_add_node_to_devs(
struct se_device *dev;
mutex_lock(&tpg->tpg_lun_mutex);
- hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
+ hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link,
+ tpg_lun_mutex_held()) {
if (lun_orig && lun != lun_orig)
continue;
- dev = rcu_dereference_check(lun->lun_se_dev,
- lockdep_is_held(&tpg->tpg_lun_mutex));
+ dev = rcu_dereference_check(lun->lun_se_dev, tpg_lun_mutex_held());
/*
* By default in LIO-Target $FABRIC_MOD,
* demo_mode_write_protect is ON, or READ_ONLY;
--
2.24.1
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
next prev parent reply other threads:[~2020-01-10 17:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 17:05 [Linux-kernel-mentees] [PATCH v2 1/3] drivers: target: target_core_device: Pass lockdep expression to RCU lists Amol Grover
2020-01-10 17:05 ` Amol Grover [this message]
2020-01-10 17:05 ` [Linux-kernel-mentees] [PATCH v2 3/3] drivers: target: tcm_fc: tfc_sess: " Amol Grover
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200110170558.23466-2-frextrite@gmail.com \
--to=frextrite@gmail.com \
--cc=joel@joelfernandes.org \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=paulmck@kernel.org \
--cc=target-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).