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Message-Id: <20200720155902.181712-17-hch@lst.de>
Date: Mon, 20 Jul 2020 17:58:54 +0200
From: Christoph Hellwig <hch@....de>
To: Al Viro <viro@...iv.linux.org.uk>,
Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Rafael J. Wysocki" <rafael@...nel.org>,
linux-kernel@...r.kernel.org, linux-raid@...r.kernel.org,
linux-fsdevel@...r.kernel.org, linux-api@...r.kernel.org
Subject: [PATCH 16/24] fs: add a kern_symlink helper
Add a simple helper perform a symlink with a kernel space file name and
use it in the early init code instead of relying on the implicit
set_fs(KERNEL_DS) there. To do so push the getname from do_symlinkat
into the callers. Remove the now unused ksys_symlink.
Signed-off-by: Christoph Hellwig <hch@....de>
---
fs/internal.h | 2 --
fs/namei.c | 27 ++++++++++++++++++---------
include/linux/fs.h | 1 +
include/linux/syscalls.h | 9 ---------
init/initramfs.c | 2 +-
5 files changed, 20 insertions(+), 21 deletions(-)
diff --git a/fs/internal.h b/fs/internal.h
index f0869d5dc4dbfa..46f727c0bd84e2 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -64,8 +64,6 @@ extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
const char *, unsigned int, struct path *);
long do_rmdir(int dfd, const char __user *pathname);
long do_unlinkat(int dfd, struct filename *name);
-long do_symlinkat(const char __user *oldname, int newdfd,
- const char __user *newname);
/*
* namespace.c
diff --git a/fs/namei.c b/fs/namei.c
index 9d80a5bce1051a..01e43676008644 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3991,20 +3991,21 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
}
EXPORT_SYMBOL(vfs_symlink);
-long do_symlinkat(const char __user *oldname, int newdfd,
- const char __user *newname)
+static int do_symlinkat(struct filename *from, int newdfd,
+ struct filename *newname)
{
int error;
- struct filename *from;
struct dentry *dentry;
struct path path;
unsigned int lookup_flags = 0;
- from = getname(oldname);
- if (IS_ERR(from))
+ if (IS_ERR(from)) {
+ if (!IS_ERR(newname))
+ putname(newname);
return PTR_ERR(from);
+ }
retry:
- dentry = user_path_create(newdfd, newname, &path, lookup_flags);
+ dentry = filename_create(newdfd, newname, &path, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_putname;
@@ -4017,20 +4018,28 @@ long do_symlinkat(const char __user *oldname, int newdfd,
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
+ putname(newname);
out_putname:
- putname(from);
+ if (!IS_ERR(from))
+ putname(from);
return error;
}
+int __init kern_symlink(const char *oldname, const char *newname)
+{
+ return do_symlinkat(getname_kernel(oldname), AT_FDCWD,
+ getname_kernel(newname));
+}
+
SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
int, newdfd, const char __user *, newname)
{
- return do_symlinkat(oldname, newdfd, newname);
+ return do_symlinkat(getname(oldname), newdfd, getname(newname));
}
SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname)
{
- return do_symlinkat(oldname, AT_FDCWD, newname);
+ return do_symlinkat(getname(oldname), AT_FDCWD, getname(newname));
}
/**
diff --git a/include/linux/fs.h b/include/linux/fs.h
index fc3b09d473945f..7a7b3bf1b8aa53 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3680,5 +3680,6 @@ int __init kern_utimes(const char *filename, struct timespec64 *tv, int flags);
int kern_mkdir(const char *pathname, umode_t mode);
int kern_mknod(const char *filename, umode_t mode, unsigned int dev);
int __init kern_link(const char *oldname, const char *newname);
+int __init kern_symlink(const char *oldname, const char *newname);
#endif /* _LINUX_FS_H */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 467cc4413874ed..474d5d165048c8 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1284,15 +1284,6 @@ static inline long ksys_rmdir(const char __user *pathname)
return do_rmdir(AT_FDCWD, pathname);
}
-extern long do_symlinkat(const char __user *oldname, int newdfd,
- const char __user *newname);
-
-static inline long ksys_symlink(const char __user *oldname,
- const char __user *newname)
-{
- return do_symlinkat(oldname, AT_FDCWD, newname);
-}
-
extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
static inline long ksys_ftruncate(unsigned int fd, loff_t length)
diff --git a/init/initramfs.c b/init/initramfs.c
index e484381c6c131b..4efd78427996da 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -389,7 +389,7 @@ static int __init do_symlink(void)
{
collected[N_ALIGN(name_len) + body_len] = '\0';
clean_path(collected, 0);
- ksys_symlink(collected + N_ALIGN(name_len), collected);
+ kern_symlink(collected + N_ALIGN(name_len), collected);
kern_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
do_utime(collected, mtime);
state = SkipIt;
--
2.27.0
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