[PATCH 04/24] devtmpfs: open code do_mount
From: Christoph Hellwig <hch@lst.de>
Date: 2020-07-21 16:30:19
Also in:
linux-fsdevel, linux-raid, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, filesystems (vfs and infrastructure), the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Alexander Viro, Christian Brauner, Linus Torvalds
Replace do_umount with an open coded version that takes the proper kernel pointer instead of relying on the implicit set_fs(KERNEL_DS) during early init. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/base/devtmpfs.c | 17 +++++++++++++++-- fs/namespace.c | 2 +- include/linux/mount.h | 3 +++ 3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index c9017e0584c003..5e8d677ee783bc 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c@@ -345,6 +345,19 @@ static int handle_remove(const char *nodename, struct device *dev) return err; } +static int devtmpfs_do_mount(const char __user *dir_name) +{ + struct path p; + int ret; + + ret = kern_path(dir_name, LOOKUP_FOLLOW, &p); + if (ret) + return ret; + ret = path_mount("devtmpfs", &p, "devtmpfs", MS_SILENT, NULL); + path_put(&p); + return ret; +} + /* * If configured, or requested by the commandline, devtmpfs will be * auto-mounted after the kernel mounted the root filesystem.
@@ -359,7 +372,7 @@ int __init devtmpfs_mount(void) if (!thread) return 0; - err = do_mount("devtmpfs", "dev", "devtmpfs", MS_SILENT, NULL); + err = devtmpfs_do_mount("dev"); if (err) printk(KERN_INFO "devtmpfs: error mounting %i\n", err); else
@@ -385,7 +398,7 @@ static int devtmpfs_setup(void *p) err = ksys_unshare(CLONE_NEWNS); if (err) goto out; - err = do_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL); + err = devtmpfs_do_mount("/"); if (err) goto out; ksys_chdir("/.."); /* will traverse into overmounted root */
diff --git a/fs/namespace.c b/fs/namespace.c
index 43834b59eff6c3..2c4d7592097485 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c@@ -3111,7 +3111,7 @@ char *copy_mount_string(const void __user *data) * Therefore, if this magic number is present, it carries no information * and must be discarded. */ -static int path_mount(const char *dev_name, struct path *path, +int path_mount(const char *dev_name, struct path *path, const char *type_page, unsigned long flags, void *data_page) { unsigned int mnt_flags = 0, sb_flags;
diff --git a/include/linux/mount.h b/include/linux/mount.h
index de657bd211fa64..bf9896f86a48f4 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h@@ -113,4 +113,7 @@ extern bool path_is_mountpoint(const struct path *path); extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num); +int path_mount(const char *dev_name, struct path *path, const char *type_page, + unsigned long flags, void *data_page); + #endif /* _LINUX_MOUNT_H */
--
2.27.0