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| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-11 11:34:53 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-02 20:15:57 +0200 |
| commit | 46ea89eb652a365e10257016d09dcf1aaf23cf63 (patch) | |
| tree | 4bee67aac3e8b19f76aa076ed863f6336013c945 /fs | |
| parent | 87c4e19262d81862886207be3c8795f6576d5a52 (diff) | |
| download | linux-46ea89eb652a365e10257016d09dcf1aaf23cf63.tar.bz2 | |
fs: add do_linkat() helper and ksys_link() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_linkat() helper allows us to get rid of
fs-internal calls to the sys_linkat() syscall.
Introducing the ksys_link() wrapper allows us to avoid the in-kernel
calls to sys_link() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_link().
In the near future, the only fs-external user of ksys_link() should be
converted to use vfs_link() instead.
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/internal.h | 2 | ||||
| -rw-r--r-- | fs/namei.c | 12 |
2 files changed, 11 insertions, 3 deletions
diff --git a/fs/internal.h b/fs/internal.h index 4f0b67054c54..91e6fc93fcb5 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -62,6 +62,8 @@ 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); +int do_linkat(int olddfd, const char __user *oldname, int newdfd, + const char __user *newname, int flags); /* * namespace.c diff --git a/fs/namei.c b/fs/namei.c index 8459a18cdd18..10148235829f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4250,8 +4250,8 @@ EXPORT_SYMBOL(vfs_link); * with linux 2.0, and to avoid hard-linking to directories * and other special files. --ADM */ -SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, - int, newdfd, const char __user *, newname, int, flags) +int do_linkat(int olddfd, const char __user *oldname, int newdfd, + const char __user *newname, int flags) { struct dentry *new_dentry; struct path old_path, new_path; @@ -4315,9 +4315,15 @@ out: return error; } +SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, int, flags) +{ + return do_linkat(olddfd, oldname, newdfd, newname, flags); +} + SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname) { - return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); + return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } /** |