Don't bother with redoing rw_verify_area() from default_file_splice_from()
default_file_splice_from() ends up calling vfs_write() (via very convoluted
callchain). It's an overkill, since we already have done rw_verify_area()
in the caller by the time we call vfs_write() we are under set_fs(KERNEL_DS),
so access_ok() is also pointless. Add a new helper (__kernel_write()),
use it instead of kernel_write() in there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/internal.h b/fs/internal.h
index 507141f..4be7823 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -125,3 +125,8 @@
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
+
+/*
+ * read_write.c
+ */
+extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);