From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org
Subject: [PATCH 08/21] init: add an init_umount helper
Date: Sun, 26 Jul 2020 09:13:43 +0200 [thread overview]
Message-ID: <20200726071356.287160-9-hch@lst.de> (raw)
In-Reply-To: <20200726071356.287160-1-hch@lst.de>
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/for_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/for_init.c b/fs/for_init.c
index 6a04cc8d8557c4..7a039b6d107c92 100644
--- a/fs/for_init.c
+++ b/fs/for_init.c
@@ -19,3 +19,17 @@ 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
next prev parent reply other threads:[~2020-07-26 7:15 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-26 7:13 add file system helpers that take kernel pointers for the init code v3 Christoph Hellwig
2020-07-26 7:13 ` [PATCH 01/21] fs: refactor do_mount Christoph Hellwig
2020-07-26 7:13 ` [PATCH 02/21] fs: refactor ksys_umount Christoph Hellwig
2020-07-26 7:13 ` [PATCH 03/21] fs: push the getname from do_rmdir into the callers Christoph Hellwig
2020-07-26 7:13 ` [PATCH 04/21] devtmpfs: refactor devtmpfsd() Christoph Hellwig
2020-07-26 7:43 ` Greg Kroah-Hartman
2020-07-26 8:21 ` Christoph Hellwig
2020-07-26 7:13 ` [PATCH 05/21] init: initialize ramdisk_execute_command at compile time Christoph Hellwig
2020-07-26 7:13 ` [PATCH 06/21] init: mark create_dev as __init Christoph Hellwig
2020-07-26 7:13 ` [PATCH 07/21] init: add an init_mount helper Christoph Hellwig
2020-07-26 7:13 ` Christoph Hellwig [this message]
2020-07-26 7:13 ` [PATCH 09/21] init: add an init_unlink helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 10/21] init: add an init_rmdir helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 11/21] init: add an init_chdir helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 12/21] init: add an init_chroot helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 13/21] init: add an init_chown helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 14/21] init: add an init_chmod helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 15/21] init: add an init_eaccess helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 16/21] init: add an init_link helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 17/21] init: add an init_symlink helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 18/21] init: add an init_mkdir helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 19/21] init: add an init_mknod helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 20/21] init: add an init_stat helper Christoph Hellwig
2020-07-26 7:13 ` [PATCH 21/21] init: add an init_utimes helper Christoph Hellwig
2020-07-26 15:49 ` add file system helpers that take kernel pointers for the init code v3 Linus Torvalds
2020-07-26 15:52 ` Christoph Hellwig
2020-07-26 16:21 ` Al Viro
2020-07-26 16:24 ` Christoph Hellwig
2020-07-26 16:26 ` Christoph Hellwig
2020-07-26 16:33 ` Al Viro
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