From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 17 Jan 2022 10:06:56 +0000 (+0100)
Subject: 5.16-stable patches
X-Git-Tag: v5.16.2~32
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7509fb50bbad4c30d910dede064baae039de1d94;p=thirdparty%2Fkernel%2Fstable-queue.git

5.16-stable patches

added patches:
	devtmpfs-regression-fix-reconfigure-on-each-mount.patch
---

diff --git a/queue-5.16/devtmpfs-regression-fix-reconfigure-on-each-mount.patch b/queue-5.16/devtmpfs-regression-fix-reconfigure-on-each-mount.patch
new file mode 100644
index 00000000000..febf754903e
--- /dev/null
+++ b/queue-5.16/devtmpfs-regression-fix-reconfigure-on-each-mount.patch
@@ -0,0 +1,73 @@
+From a6097180d884ddab769fb25588ea8598589c218c Mon Sep 17 00:00:00 2001
+From: NeilBrown <neilb@suse.de>
+Date: Mon, 17 Jan 2022 09:07:26 +1100
+Subject: devtmpfs regression fix: reconfigure on each mount
+
+From: NeilBrown <neilb@suse.de>
+
+commit a6097180d884ddab769fb25588ea8598589c218c upstream.
+
+Prior to Linux v5.4 devtmpfs used mount_single() which treats the given
+mount options as "remount" options, so it updates the configuration of
+the single super_block on each mount.
+
+Since that was changed, the mount options used for devtmpfs are ignored.
+This is a regression which affect systemd - which mounts devtmpfs with
+"-o mode=755,size=4m,nr_inodes=1m".
+
+This patch restores the "remount" effect by calling reconfigure_single()
+
+Fixes: d401727ea0d7 ("devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()")
+Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
+Cc: Al Viro <viro@zeniv.linux.org.uk>
+Signed-off-by: NeilBrown <neilb@suse.de>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/base/devtmpfs.c    |    7 +++++++
+ fs/super.c                 |    4 ++--
+ include/linux/fs_context.h |    2 ++
+ 3 files changed, 11 insertions(+), 2 deletions(-)
+
+--- a/drivers/base/devtmpfs.c
++++ b/drivers/base/devtmpfs.c
+@@ -59,8 +59,15 @@ static struct dentry *public_dev_mount(s
+ 		      const char *dev_name, void *data)
+ {
+ 	struct super_block *s = mnt->mnt_sb;
++	int err;
++
+ 	atomic_inc(&s->s_active);
+ 	down_write(&s->s_umount);
++	err = reconfigure_single(s, flags, data);
++	if (err < 0) {
++		deactivate_locked_super(s);
++		return ERR_PTR(err);
++	}
+ 	return dget(s->s_root);
+ }
+ 
+--- a/fs/super.c
++++ b/fs/super.c
+@@ -1423,8 +1423,8 @@ struct dentry *mount_nodev(struct file_s
+ }
+ EXPORT_SYMBOL(mount_nodev);
+ 
+-static int reconfigure_single(struct super_block *s,
+-			      int flags, void *data)
++int reconfigure_single(struct super_block *s,
++		       int flags, void *data)
+ {
+ 	struct fs_context *fc;
+ 	int ret;
+--- a/include/linux/fs_context.h
++++ b/include/linux/fs_context.h
+@@ -142,6 +142,8 @@ extern void put_fs_context(struct fs_con
+ extern int vfs_parse_fs_param_source(struct fs_context *fc,
+ 				     struct fs_parameter *param);
+ extern void fc_drop_locked(struct fs_context *fc);
++int reconfigure_single(struct super_block *s,
++		       int flags, void *data);
+ 
+ /*
+  * sget() wrappers to be called from the ->get_tree() op.
diff --git a/queue-5.16/series b/queue-5.16/series
new file mode 100644
index 00000000000..12787d2c4b5
--- /dev/null
+++ b/queue-5.16/series
@@ -0,0 +1 @@
+devtmpfs-regression-fix-reconfigure-on-each-mount.patch