From: NeilBrown neilb@suse.de
stable inclusion from stable-v5.10.93 commit 0084fefe2960b3a0c6482558272ee6372c75e3d4 bugzilla: 186204 https://gitee.com/openeuler/kernel/issues/I5311N
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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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 Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- drivers/base/devtmpfs.c | 7 +++++++ fs/super.c | 4 ++-- include/linux/fs_context.h | 2 ++ 3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index a71d14117943..b5cbaa61cbea 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -59,8 +59,15 @@ static struct dentry *public_dev_mount(struct file_system_type *fs_type, int fla 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); }
diff --git a/fs/super.c b/fs/super.c index 494bfdc6f778..e692950bcf52 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1472,8 +1472,8 @@ struct dentry *mount_nodev(struct file_system_type *fs_type, } 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; diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h index 6b54982fc5f3..13fa6f3df8e4 100644 --- a/include/linux/fs_context.h +++ b/include/linux/fs_context.h @@ -142,6 +142,8 @@ extern void put_fs_context(struct fs_context *fc); 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.