CIFS: Respect SMB2 header/max header size

Use SMB2 header size values for allocation and memset because they
are bigger and suitable for both CIFS and SMB2.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>

2 files changed, 31 insertions, 8 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 2e9929dc2072..7a7cda9f7912 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -48,6 +48,9 @@
 #include <linux/key-type.h>
 #include "cifs_spnego.h"
 #include "fscache.h"
+#ifdef CONFIG_CIFS_SMB2
+#include "smb2pdu.h"
+#endif
 #define CIFS_MAGIC_NUMBER 0xFF534D42    /* the first four bytes of SMB PDUs */
 
 int cifsFYI = 0;
@@ -980,6 +983,14 @@ cifs_destroy_inodecache(void)
 static int
 cifs_init_request_bufs(void)
 {
+        size_t max_hdr_size = MAX_CIFS_HDR_SIZE;
+#ifdef CONFIG_CIFS_SMB2
+        /*
+         * SMB2 maximum header size is bigger than CIFS one - no problems to
+         * allocate some more bytes for CIFS.
+         */
+        max_hdr_size = MAX_SMB2_HDR_SIZE;
+#endif
         if (CIFSMaxBufSize < 8192) {
         /* Buffer size can not be smaller than 2 * PATH_MAX since maximum
         Unicode path name has to fit in any SMB/CIFS path based frames */
@@ -991,8 +1002,7 @@ cifs_init_request_bufs(void)
         }
 /*      cERROR(1, "CIFSMaxBufSize %d 0x%x",CIFSMaxBufSize,CIFSMaxBufSize); */
         cifs_req_cachep = kmem_cache_create("cifs_request",
-                                            CIFSMaxBufSize +
-                                            MAX_CIFS_HDR_SIZE, 0,
+                                            CIFSMaxBufSize + max_hdr_size, 0,
                                             SLAB_HWCACHE_ALIGN, NULL);
         if (cifs_req_cachep == NULL)
                 return -ENOMEM;
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 64601146f157..ad2538a64c70 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -29,6 +29,9 @@
 #include "smberr.h"
 #include "nterr.h"
 #include "cifs_unicode.h"
+#ifdef CONFIG_CIFS_SMB2
+#include "smb2pdu.h"
+#endif
 
 extern mempool_t *cifs_sm_req_poolp;
 extern mempool_t *cifs_req_poolp;
@@ -143,17 +146,27 @@ struct smb_hdr *
 cifs_buf_get(void)
 {
         struct smb_hdr *ret_buf = NULL;
-
-/* We could use negotiated size instead of max_msgsize -
-   but it may be more efficient to always alloc same size
-   albeit slightly larger than necessary and maxbuffersize
-   defaults to this and can not be bigger */
+        size_t buf_size = sizeof(struct smb_hdr);
+
+#ifdef CONFIG_CIFS_SMB2
+        /*
+         * SMB2 header is bigger than CIFS one - no problems to clean some
+         * more bytes for CIFS.
+         */
+        buf_size = sizeof(struct smb2_hdr);
+#endif
+        /*
+         * We could use negotiated size instead of max_msgsize -
+         * but it may be more efficient to always alloc same size
+         * albeit slightly larger than necessary and maxbuffersize
+         * defaults to this and can not be bigger.
+         */
         ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
 
         /* clear the first few header bytes */
         /* for most paths, more is cleared in header_assemble */
         if (ret_buf) {
-                memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
+                memset(ret_buf, 0, buf_size + 3);
                 atomic_inc(&bufAllocCount);
 #ifdef CONFIG_CIFS_STATS2
                 atomic_inc(&totBufAllocCount);