cifs: add cifs_async_writev

Add the ability for CIFS to do an asynchronous write. The kernel will
set the frame up as it would for a "normal" SMBWrite2 request, and use
cifs_call_async to send it. The mid callback will then be configured to
handle the result.

Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index fdc0dc2c083c..8aea8850ffee 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -442,4 +442,22 @@ extern int mdfour(unsigned char *, unsigned char *, int);
 extern int E_md4hash(const unsigned char *passwd, unsigned char *p16);
 extern int SMBencrypt(unsigned char *passwd, const unsigned char *c8,
                         unsigned char *p24);
+
+/* asynchronous write support */
+struct cifs_writedata {
+        struct kref                     refcount;
+        enum writeback_sync_modes       sync_mode;
+        struct work_struct              work;
+        struct cifsFileInfo             *cfile;
+        __u64                           offset;
+        unsigned int                    bytes;
+        int                             result;
+        unsigned int                    nr_pages;
+        struct page                     *pages[1];
+};
+
+int cifs_async_writev(struct cifs_writedata *wdata);
+struct cifs_writedata *cifs_writedata_alloc(unsigned int nr_pages);
+void cifs_writedata_release(struct kref *refcount);
+
 #endif                  /* _CIFSPROTO_H */