[PATCH 09/23] init: add an init_umount helper
From: Christoph Hellwig <hch@lst.de>
Date: 2020-07-28 16:36:07
Also in:
linux-fsdevel, linux-raid, lkml
Subsystem:
abi/api, filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Like ksys_umount, but takes a kernel pointer for the destination path. Switch over the umount in the init code, which just happen to work due to the implicit set_fs(KERNEL_DS) during early init right now. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/init.c | 14 ++++++++++++++ fs/internal.h | 1 + fs/namespace.c | 4 ++-- include/linux/init_syscalls.h | 1 + include/linux/syscalls.h | 1 - init/do_mounts_initrd.c | 2 +- 6 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/fs/init.c b/fs/init.c
index c6eb724e1c7b22..9c8e31fdb048c8 100644
--- a/fs/init.c
+++ b/fs/init.c@@ -23,3 +23,17 @@ int __init init_mount(const char *dev_name, const char *dir_name, path_put(&path); return ret; } + +int __init init_umount(const char *name, int flags) +{ + int lookup_flags = LOOKUP_MOUNTPOINT; + struct path path; + int ret; + + if (!(flags & UMOUNT_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + ret = kern_path(name, lookup_flags, &path); + if (ret) + return ret; + return path_umount(&path, flags); +}
diff --git a/fs/internal.h b/fs/internal.h
index 72ea0b6f7435a4..491d1e63809b37 100644
--- a/fs/internal.h
+++ b/fs/internal.h@@ -92,6 +92,7 @@ extern void dissolve_on_fput(struct vfsmount *); int path_mount(const char *dev_name, struct path *path, const char *type_page, unsigned long flags, void *data_page); +int path_umount(struct path *path, int flags); /* * fs_struct.c
diff --git a/fs/namespace.c b/fs/namespace.c
index 2c4d7592097485..a7301790abb211 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c@@ -1706,7 +1706,7 @@ static inline bool may_mandlock(void) } #endif -static int path_umount(struct path *path, int flags) +int path_umount(struct path *path, int flags) { struct mount *mnt; int retval;
@@ -1736,7 +1736,7 @@ static int path_umount(struct path *path, int flags) return retval; } -int ksys_umount(char __user *name, int flags) +static int ksys_umount(char __user *name, int flags) { int lookup_flags = LOOKUP_MOUNTPOINT; struct path path;
diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h
index af9ea88a60e0bd..a5a2e7f1991691 100644
--- a/include/linux/init_syscalls.h
+++ b/include/linux/init_syscalls.h@@ -2,3 +2,4 @@ int __init init_mount(const char *dev_name, const char *dir_name, const char *type_page, unsigned long flags, void *data_page); +int __init init_umount(const char *name, int flags);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e43816198e6001..1a4f5d8ee7044b 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h@@ -1236,7 +1236,6 @@ asmlinkage long sys_ni_syscall(void); * the ksys_xyzyyz() functions prototyped below. */ -int ksys_umount(char __user *name, int flags); int ksys_chroot(const char __user *filename); ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count); int ksys_chdir(const char __user *filename);
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index 1f9336209ad9cc..6b020a06990251 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c@@ -122,7 +122,7 @@ static void __init handle_initrd(void) else printk("failed\n"); printk(KERN_NOTICE "Unmounting old root\n"); - ksys_umount("/old", MNT_DETACH); + init_umount("/old", MNT_DETACH); } }
--
2.27.0