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 17/23] init: add an init_link helper
Date: Tue, 28 Jul 2020 18:34:10 +0200 [thread overview]
Message-ID: <20200728163416.556521-18-hch@lst.de> (raw)
In-Reply-To: <20200728163416.556521-1-hch@lst.de>
Add a simple helper to link with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_link.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/init.c | 33 +++++++++++++++++++++++++++++++++
fs/internal.h | 3 +--
fs/namei.c | 4 ++--
include/linux/init_syscalls.h | 1 +
include/linux/syscalls.h | 9 ---------
init/initramfs.c | 2 +-
6 files changed, 38 insertions(+), 14 deletions(-)
diff --git a/fs/init.c b/fs/init.c
index 6d9af40d2897b1..5db9d9f74868e1 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -122,6 +122,39 @@ int __init init_eaccess(const char *filename)
return error;
}
+int __init init_link(const char *oldname, const char *newname)
+{
+ struct dentry *new_dentry;
+ struct path old_path, new_path;
+ int error;
+
+ error = kern_path(oldname, 0, &old_path);
+ if (error)
+ return error;
+
+ new_dentry = kern_path_create(AT_FDCWD, newname, &new_path, 0);
+ error = PTR_ERR(new_dentry);
+ if (IS_ERR(new_dentry))
+ goto out;
+
+ error = -EXDEV;
+ if (old_path.mnt != new_path.mnt)
+ goto out_dput;
+ error = may_linkat(&old_path);
+ if (unlikely(error))
+ goto out_dput;
+ error = security_path_link(old_path.dentry, &new_path, new_dentry);
+ if (error)
+ goto out_dput;
+ error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry,
+ NULL);
+out_dput:
+ done_path_create(&new_path, new_dentry);
+out:
+ path_put(&old_path);
+ return error;
+}
+
int __init init_unlink(const char *pathname)
{
return do_unlinkat(AT_FDCWD, getname_kernel(pathname));
diff --git a/fs/internal.h b/fs/internal.h
index 6d82681c7d8372..58451b033d2698 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -69,8 +69,7 @@ long do_rmdir(int dfd, struct filename *name);
long do_unlinkat(int dfd, struct filename *name);
long do_symlinkat(const char __user *oldname, int newdfd,
const char __user *newname);
-int do_linkat(int olddfd, const char __user *oldname, int newdfd,
- const char __user *newname, int flags);
+int may_linkat(struct path *link);
/*
* namespace.c
diff --git a/fs/namei.c b/fs/namei.c
index d75a6039ae3966..13de64c6be7640 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1024,7 +1024,7 @@ static bool safe_hardlink_source(struct inode *inode)
*
* Returns 0 if successful, -ve on error.
*/
-static int may_linkat(struct path *link)
+int may_linkat(struct path *link)
{
struct inode *inode = link->dentry->d_inode;
@@ -4086,7 +4086,7 @@ EXPORT_SYMBOL(vfs_link);
* with linux 2.0, and to avoid hard-linking to directories
* and other special files. --ADM
*/
-int do_linkat(int olddfd, const char __user *oldname, int newdfd,
+static int do_linkat(int olddfd, const char __user *oldname, int newdfd,
const char __user *newname, int flags)
{
struct dentry *new_dentry;
diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h
index 7031c0934bee9f..5ca15a5b55b7d7 100644
--- a/include/linux/init_syscalls.h
+++ b/include/linux/init_syscalls.h
@@ -8,5 +8,6 @@ int __init init_chroot(const char *filename);
int __init init_chown(const char *filename, uid_t user, gid_t group, int flags);
int __init init_chmod(const char *filename, umode_t mode);
int __init init_eaccess(const char *filename);
+int __init init_link(const char *oldname, const char *newname);
int __init init_unlink(const char *pathname);
int __init init_rmdir(const char *pathname);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a2779638e41445..4b18b91ce46573 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1295,15 +1295,6 @@ static inline long ksys_mknod(const char __user *filename, umode_t mode,
return do_mknodat(AT_FDCWD, filename, mode, dev);
}
-extern int do_linkat(int olddfd, const char __user *oldname, int newdfd,
- const char __user *newname, int flags);
-
-static inline long ksys_link(const char __user *oldname,
- const char __user *newname)
-{
- return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
-}
-
extern int do_fchownat(int dfd, const char __user *filename, uid_t user,
gid_t group, int flag);
diff --git a/init/initramfs.c b/init/initramfs.c
index 21a75f6ca893a9..a3d29318cc351d 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -312,7 +312,7 @@ static int __init maybe_link(void)
char *old = find_link(major, minor, ino, mode, collected);
if (old) {
clean_path(collected, 0);
- return (ksys_link(old, collected) < 0) ? -1 : 1;
+ return (init_link(old, collected) < 0) ? -1 : 1;
}
}
return 0;
--
2.27.0
next prev parent reply other threads:[~2020-07-28 16:34 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-28 16:33 add file system helpers that take kernel pointers for the init code v4 Christoph Hellwig
2020-07-28 16:33 ` [PATCH 01/23] fs: refactor do_mount Christoph Hellwig
2020-07-28 16:33 ` [PATCH 02/23] fs: refactor ksys_umount Christoph Hellwig
[not found] ` <20200728163416.556521-3-hch-jcswGhMUV9g@public.gmane.org>
2020-08-06 14:44 ` Naresh Kamboju
2020-08-17 13:44 ` Naresh Kamboju
2020-07-28 16:33 ` [PATCH 03/23] fs: push the getname from do_rmdir into the callers Christoph Hellwig
2020-07-28 16:33 ` [PATCH 05/23] init: initialize ramdisk_execute_command at compile time Christoph Hellwig
2020-07-28 16:34 ` [PATCH 08/23] init: add an init_mount helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 09/23] init: add an init_umount helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 10/23] init: add an init_unlink helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 11/23] init: add an init_rmdir helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 12/23] init: add an init_chdir helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 13/23] init: add an init_chroot helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 14/23] init: add an init_chown helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 15/23] init: add an init_chmod helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 16/23] init: add an init_eaccess helper Christoph Hellwig
2020-07-28 16:34 ` Christoph Hellwig [this message]
2020-07-28 16:34 ` [PATCH 18/23] init: add an init_symlink helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 19/23] init: add an init_mkdir helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 20/23] init: add an init_mknod helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 21/23] init: add an init_stat helper Christoph Hellwig
2020-09-04 13:53 ` [PATCH] init: fix error check in clean_path() Barret Rhoden
2020-09-04 16:04 ` Christoph Hellwig
[not found] ` <20200728163416.556521-1-hch-jcswGhMUV9g@public.gmane.org>
2020-07-28 16:33 ` [PATCH 04/23] devtmpfs: refactor devtmpfsd() Christoph Hellwig
2020-07-28 16:59 ` Greg Kroah-Hartman
2020-07-28 16:33 ` [PATCH 06/23] init: mark console_on_rootfs as __init Christoph Hellwig
2020-07-28 16:34 ` [PATCH 07/23] init: mark create_dev " Christoph Hellwig
2020-07-28 16:34 ` [PATCH 22/23] init: add an init_utimes helper Christoph Hellwig
2020-07-28 16:34 ` [PATCH 23/23] init: add an init_dup helper Christoph Hellwig
2020-07-29 19:51 ` add file system helpers that take kernel pointers for the init code v4 Al Viro
2020-07-30 6:25 ` Christoph Hellwig
2020-07-31 2:14 ` Al Viro
[not found] ` <20200731021424.GG1236603-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2020-07-31 6:33 ` Christoph Hellwig
2020-08-03 14:56 ` Qian Cai
[not found] ` <20200803145622.GB4631-J5quhbR+WMc@public.gmane.org>
2020-08-03 15:08 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200728163416.556521-18-hch@lst.de \
--to=hch@lst.de \
--cc=gregkh@linuxfoundation.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=rafael@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).