fs: make two stat prep helpers available

To implement an async stat, we need to provide the flags mapping and
the statx user copy. Make them available internally, through
fs/internal.h.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/internal.h b/fs/internal.h
index c4baf42..54e2835 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -190,3 +190,9 @@ extern int do_vfs_ioctl(struct file *file, unsigned int fd, unsigned int cmd,
 
 /* direct-io.c: */
 int sb_init_dio_done_wq(struct super_block *sb);
+
+/*
+ * fs/stat.c:
+ */
+unsigned vfs_stat_set_lookup_flags(unsigned *lookup_flags, int flags);
+int cp_statx(const struct kstat *stat, struct statx __user *buffer);

diff --git a/fs/stat.c b/fs/stat.c
index c38e4c2..0300087 100644 (file)
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -21,6 +21,8 @@
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
 
+#include "internal.h"
+
 /**
  * generic_fillattr - Fill in the basic attributes from the inode struct
  * @inode: Inode to use as the source
@@ -150,6 +152,23 @@ int vfs_statx_fd(unsigned int fd, struct kstat *stat,
 }
 EXPORT_SYMBOL(vfs_statx_fd);
 
+inline unsigned vfs_stat_set_lookup_flags(unsigned *lookup_flags, int flags)
+{
+       if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
+                      AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
+               return -EINVAL;
+
+       *lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
+       if (flags & AT_SYMLINK_NOFOLLOW)
+               *lookup_flags &= ~LOOKUP_FOLLOW;
+       if (flags & AT_NO_AUTOMOUNT)
+               *lookup_flags &= ~LOOKUP_AUTOMOUNT;
+       if (flags & AT_EMPTY_PATH)
+               *lookup_flags |= LOOKUP_EMPTY;
+
+       return 0;
+}
+
 /**
  * vfs_statx - Get basic and extra attributes by filename
  * @dfd: A file descriptor representing the base dir for a relative filename
@@ -170,19 +189,10 @@ int vfs_statx(int dfd, const char __user *filename, int flags,
 {
        struct path path;
        int error = -EINVAL;
-       unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
+       unsigned lookup_flags;
 
-       if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
-                      AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
+       if (vfs_stat_set_lookup_flags(&lookup_flags, flags))
                return -EINVAL;
-
-       if (flags & AT_SYMLINK_NOFOLLOW)
-               lookup_flags &= ~LOOKUP_FOLLOW;
-       if (flags & AT_NO_AUTOMOUNT)
-               lookup_flags &= ~LOOKUP_AUTOMOUNT;
-       if (flags & AT_EMPTY_PATH)
-               lookup_flags |= LOOKUP_EMPTY;
-
 retry:
        error = user_path_at(dfd, filename, lookup_flags, &path);
        if (error)
@@ -523,7 +533,7 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
 }
 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
 
-static noinline_for_stack int
+noinline_for_stack int
 cp_statx(const struct kstat *stat, struct statx __user *buffer)
 {
        struct statx tmp;