Separate out common fstatat code into vfs_fstatat

This is a version incorporating Christoph's suggestion.

Separate out common *fstatat functionality into a single function
instead of duplicating it all over the code.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

7 files changed, 54 insertions, 97 deletions

diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index e04173c7e62..d59a0cd537f 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -177,21 +177,12 @@ asmlinkage long sys_oabi_fstatat64(int dfd,
                                    int flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
+        int error;
 
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
-
-        if (!error)
-        error = cp_oldabi_stat64(&stat, statbuf);
-
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_oldabi_stat64(&stat, statbuf);
 }
 
 struct oabi_flock64 {
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 6cc87d8c868..002c70d3cb7 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -702,20 +702,12 @@ asmlinkage long sys32_fstatat64(unsigned int dfd, char __user *filename,
                                 struct stat64_emu31 __user* statbuf, int flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
-
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
+        int error;
 
-        if (!error)
-                error = cp_stat64(statbuf, &stat);
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_stat64(statbuf, &stat);
 }
 
 /*
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index e800503879e..f5000a460c0 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -206,21 +206,12 @@ asmlinkage long compat_sys_fstatat64(unsigned int dfd, char __user *filename,
                 struct compat_stat64 __user * statbuf, int flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
-
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
-
-        if (!error)
-                error = cp_compat_stat64(&stat, statbuf);
+        int error;
 
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_compat_stat64(&stat, statbuf);
 }
 
 asmlinkage long compat_sys_sysfs(int option, u32 arg1, u32 arg2)
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index efac92fd1ef..085a8c35f14 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -129,21 +129,12 @@ asmlinkage long sys32_fstatat(unsigned int dfd, char __user *filename,
                               struct stat64 __user *statbuf, int flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
+        int error;
 
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
-
-        if (!error)
-                error = cp_stat64(statbuf, &stat);
-
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_stat64(statbuf, &stat);
 }
 
 /*
diff --git a/fs/compat.c b/fs/compat.c
index 3f84d5f1588..dda72e26709 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -204,21 +204,12 @@ asmlinkage long compat_sys_newfstatat(unsigned int dfd, char __user *filename,
                 struct compat_stat __user *statbuf, int flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
-
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
-
-        if (!error)
-                error = cp_compat_stat(&stat, statbuf);
+        int error;
 
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_compat_stat(&stat, statbuf);
 }
 #endif
 
diff --git a/fs/stat.c b/fs/stat.c
index 2db740a0cfb..54711662b85 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -109,6 +109,24 @@ int vfs_fstat(unsigned int fd, struct kstat *stat)
 
 EXPORT_SYMBOL(vfs_fstat);
 
+int vfs_fstatat(int dfd, char __user *filename, struct kstat *stat, int flag)
+{
+        int error = -EINVAL;
+
+        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
+                goto out;
+
+        if (flag & AT_SYMLINK_NOFOLLOW)
+                error = vfs_lstat_fd(dfd, filename, stat);
+        else
+                error = vfs_stat_fd(dfd, filename, stat);
+out:
+        return error;
+}
+
+EXPORT_SYMBOL(vfs_fstatat);
+
+
 #ifdef __ARCH_WANT_OLD_STAT
 
 /*
@@ -264,21 +282,12 @@ SYSCALL_DEFINE4(newfstatat, int, dfd, char __user *, filename,
                 struct stat __user *, statbuf, int, flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
-
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
-
-        if (!error)
-                error = cp_new_stat(&stat, statbuf);
+        int error;
 
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_new_stat(&stat, statbuf);
 }
 #endif
 
@@ -404,21 +413,12 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, char __user *, filename,
                 struct stat64 __user *, statbuf, int, flag)
 {
         struct kstat stat;
-        int error = -EINVAL;
-
-        if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
-                goto out;
-
-        if (flag & AT_SYMLINK_NOFOLLOW)
-                error = vfs_lstat_fd(dfd, filename, &stat);
-        else
-                error = vfs_stat_fd(dfd, filename, &stat);
-
-        if (!error)
-                error = cp_new_stat64(&stat, statbuf);
+        int error;
 
-out:
-        return error;
+        error = vfs_fstatat(dfd, filename, &stat, flag);
+        if (error)
+                return error;
+        return cp_new_stat64(&stat, statbuf);
 }
 #endif /* __ARCH_WANT_STAT64 */
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e766be0d432..257f4d37ad2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2302,6 +2302,7 @@ extern int vfs_lstat(char __user *, struct kstat *);
 extern int vfs_stat_fd(int dfd, char __user *, struct kstat *);
 extern int vfs_lstat_fd(int dfd, char __user *, struct kstat *);
 extern int vfs_fstat(unsigned int, struct kstat *);
+extern int vfs_fstatat(int , char __user *, struct kstat *, int);
 
 extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
                     unsigned long arg);