cifs: keep a reusable kvec array for receives

Having to continually allocate a new kvec array is expensive. Allocate
one that's big enough, and only reallocate it as needed.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 55ebf39fb3fd..51ed2de23070 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -292,6 +292,8 @@ struct TCP_Server_Info {
         bool    sec_kerberos;           /* supports plain Kerberos */
         bool    sec_mskerberos;         /* supports legacy MS Kerberos */
         struct delayed_work     echo; /* echo ping workqueue job */
+        struct kvec *iov;       /* reusable kvec array for receives */
+        unsigned int nr_iov;    /* number of kvecs in array */
 #ifdef CONFIG_CIFS_FSCACHE
         struct fscache_cookie   *fscache; /* client index cache cookie */
 #endif