Patch "md/r5cache: move mddev_lock() out of r5c_journal_mode_set()" has been added to the 4.14-stable tree

Patch "md/r5cache: move mddev_lock() out of r5c_journal_mode_set()" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    md/r5cache: move mddev_lock() out of r5c_journal_mode_set()

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     md-r5cache-move-mddev_lock-out-of-r5c_journal_mode_set.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ff35f58e8f8eb520367879a0ccc6f2ec4b62b17b Mon Sep 17 00:00:00 2001
From: Song Liu <songliubraving@fb.com>
Date: Sun, 19 Nov 2017 22:17:00 -0800
Subject: md/r5cache: move mddev_lock() out of r5c_journal_mode_set()

From: Song Liu <songliubraving@fb.com>

commit ff35f58e8f8eb520367879a0ccc6f2ec4b62b17b upstream.

r5c_journal_mode_set() is called by r5c_journal_mode_store() and
raid_ctr() in dm-raid. We don't need mddev_lock() when calling from
raid_ctr(). This patch fixes this by moves the mddev_lock() to
r5c_journal_mode_store().

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/raid5-cache.c |   22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -2571,31 +2571,22 @@ static ssize_t r5c_journal_mode_show(str
 int r5c_journal_mode_set(struct mddev *mddev, int mode)
 {
 	struct r5conf *conf;
-	int err;
 
 	if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
 	    mode > R5C_JOURNAL_MODE_WRITE_BACK)
 		return -EINVAL;
 
-	err = mddev_lock(mddev);
-	if (err)
-		return err;
 	conf = mddev->private;
-	if (!conf || !conf->log) {
-		mddev_unlock(mddev);
+	if (!conf || !conf->log)
 		return -ENODEV;
-	}
 
 	if (raid5_calc_degraded(conf) > 0 &&
-	    mode == R5C_JOURNAL_MODE_WRITE_BACK) {
-		mddev_unlock(mddev);
+	    mode == R5C_JOURNAL_MODE_WRITE_BACK)
 		return -EINVAL;
-	}
 
 	mddev_suspend(mddev);
 	conf->log->r5c_journal_mode = mode;
 	mddev_resume(mddev);
-	mddev_unlock(mddev);
 
 	pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
 		 mdname(mddev), mode, r5c_journal_mode_str[mode]);
@@ -2608,6 +2599,7 @@ static ssize_t r5c_journal_mode_store(st
 {
 	int mode = ARRAY_SIZE(r5c_journal_mode_str);
 	size_t len = length;
+	int ret;
 
 	if (len < 2)
 		return -EINVAL;
@@ -2619,8 +2611,12 @@ static ssize_t r5c_journal_mode_store(st
 		if (strlen(r5c_journal_mode_str[mode]) == len &&
 		    !strncmp(page, r5c_journal_mode_str[mode], len))
 			break;
-
-	return r5c_journal_mode_set(mddev, mode) ?: length;
+	ret = mddev_lock(mddev);
+	if (ret)
+		return ret;
+	ret = r5c_journal_mode_set(mddev, mode);
+	mddev_unlock(mddev);
+	return ret ?: length;
 }
 
 struct md_sysfs_entry


Patches currently in stable-queue which might be from songliubraving@fb.com are

queue-4.14/md-r5cache-move-mddev_lock-out-of-r5c_journal_mode_set.patch