lkml.org 
[lkml]   [2022]   [Jun]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH v4 05/11] md/raid5-cache: Take mddev_lock in r5c_journal_mode_show()
The mddev->lock spinlock doesn't protect against the removal of
conf->log in r5l_exit_log() so conf->log may be freed before it
is used.

To fix this, take the mddev_lock() insteaad of the mddev->lock spinlock.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
drivers/md/raid5-cache.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 83c184eddbda..ca8fc317da95 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -2534,12 +2534,13 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
struct r5conf *conf;
int ret;

- spin_lock(&mddev->lock);
+ ret = mddev_lock(mddev);
+ if (ret)
+ return ret;
+
conf = mddev->private;
- if (!conf || !conf->log) {
- spin_unlock(&mddev->lock);
- return 0;
- }
+ if (!conf || !conf->log)
+ goto out_unlock;

switch (conf->log->r5c_journal_mode) {
case R5C_JOURNAL_MODE_WRITE_THROUGH:
@@ -2557,7 +2558,9 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
default:
ret = 0;
}
- spin_unlock(&mddev->lock);
+
+out_unlock:
+ mddev_unlock(mddev);
return ret;
}

--
2.30.2
\
 
 \ /
  Last update: 2022-06-08 18:34    [W:1.395 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site