[openwrt/openwrt] generic: platform/mikrotik: release mtd device after use

[LEDE Commits]

xback pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/2f0ab9379909dbc765b0e250669f8f57254c8463

commit 2f0ab9379909dbc765b0e250669f8f57254c8463
Author: Thibaut VARÈNE <hacks at slashdirt.org>
AuthorDate: Tue May 11 12:50:21 2021 +0200

    generic: platform/mikrotik: release mtd device after use
    
    The code uses get_mtd_device_nm() which must be followed by a call to
    put_mtd_device() once the handle is no longer used.
    
    This fixes spurious shutdown console messages such as:
    [ 2256.334562] Removing MTD device #7 (soft_config) with use count 1
    
    Reported-by: Koen Vandeputte <koen.vandeputte at ncentric.com>
    Tested-by: Koen Vandeputte <koen.vandeputte at ncentric.com>
    Signed-off-by: Thibaut VARÈNE <hacks at slashdirt.org>
    (cherry picked from commit 4e385a27d6c4aab62ef7fc9856f09ebee9632985)
---
 .../linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c  | 5 ++++-
 .../linux/generic/files/drivers/platform/mikrotik/rb_softconfig.c  | 7 ++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c b/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c
index 41dea98b5e..e6a6928896 100644
--- a/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c
+++ b/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c
@@ -697,10 +697,13 @@ int __init rb_hardconfig_init(struct kobject *rb_kobj)
 
 	hc_buflen = mtd->size;
 	hc_buf = kmalloc(hc_buflen, GFP_KERNEL);
-	if (!hc_buf)
+	if (!hc_buf) {
+		put_mtd_device(mtd);
 		return -ENOMEM;
+	}
 
 	ret = mtd_read(mtd, 0, hc_buflen, &bytes_read, hc_buf);
+	put_mtd_device(mtd);
 
 	if (ret)
 		goto fail;
diff --git a/target/linux/generic/files/drivers/platform/mikrotik/rb_softconfig.c b/target/linux/generic/files/drivers/platform/mikrotik/rb_softconfig.c
index 54e263df8c..070bd32d5a 100644
--- a/target/linux/generic/files/drivers/platform/mikrotik/rb_softconfig.c
+++ b/target/linux/generic/files/drivers/platform/mikrotik/rb_softconfig.c
@@ -686,6 +686,8 @@ static ssize_t sc_commit_store(struct kobject *kobj, struct kobj_attribute *attr
 	}
 	write_unlock(&sc_bufrwl);
 
+	put_mtd_device(mtd);
+
 	if (ret)
 		goto mtdfail;
 
@@ -721,10 +723,13 @@ int __init rb_softconfig_init(struct kobject *rb_kobj)
 
 	sc_buflen = mtd->size;
 	sc_buf = kmalloc(sc_buflen, GFP_KERNEL);
-	if (!sc_buf)
+	if (!sc_buf) {
+		put_mtd_device(mtd);
 		return -ENOMEM;
+	}
 
 	ret = mtd_read(mtd, 0, sc_buflen, &bytes_read, sc_buf);
+	put_mtd_device(mtd);
 
 	if (ret)
 		goto fail;