CIFS: Move r/wsize negotiating to ops struct

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index df20dd9e64c..7e8a2bdd69c 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -17,6 +17,7 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
+#include <linux/pagemap.h>
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifs_debug.h"
@@ -410,6 +411,89 @@ cifs_negotiate(const unsigned int xid, struct cifs_ses *ses)
 	return rc;
 }
 
+static unsigned int
+cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
+{
+	__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+	struct TCP_Server_Info *server = tcon->ses->server;
+	unsigned int wsize;
+
+	/* start with specified wsize, or default */
+	if (volume_info->wsize)
+		wsize = volume_info->wsize;
+	else if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
+		wsize = CIFS_DEFAULT_IOSIZE;
+	else
+		wsize = CIFS_DEFAULT_NON_POSIX_WSIZE;
+
+	/* can server support 24-bit write sizes? (via UNIX extensions) */
+	if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
+		wsize = min_t(unsigned int, wsize, CIFS_MAX_RFC1002_WSIZE);
+
+	/*
+	 * no CAP_LARGE_WRITE_X or is signing enabled without CAP_UNIX set?
+	 * Limit it to max buffer offered by the server, minus the size of the
+	 * WRITEX header, not including the 4 byte RFC1001 length.
+	 */
+	if (!(server->capabilities & CAP_LARGE_WRITE_X) ||
+	    (!(server->capabilities & CAP_UNIX) &&
+	     (server->sec_mode & (SECMODE_SIGN_ENABLED|SECMODE_SIGN_REQUIRED))))
+		wsize = min_t(unsigned int, wsize,
+				server->maxBuf - sizeof(WRITE_REQ) + 4);
+
+	/* limit to the amount that we can kmap at once */
+	wsize = min_t(unsigned int, wsize, CIFS_KMAP_SIZE_LIMIT);
+
+	/* hard limit of CIFS_MAX_WSIZE */
+	wsize = min_t(unsigned int, wsize, CIFS_MAX_WSIZE);
+
+	return wsize;
+}
+
+static unsigned int
+cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
+{
+	__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+	struct TCP_Server_Info *server = tcon->ses->server;
+	unsigned int rsize, defsize;
+
+	/*
+	 * Set default value...
+	 *
+	 * HACK alert! Ancient servers have very small buffers. Even though
+	 * MS-CIFS indicates that servers are only limited by the client's
+	 * bufsize for reads, testing against win98se shows that it throws
+	 * INVALID_PARAMETER errors if you try to request too large a read.
+	 * OS/2 just sends back short reads.
+	 *
+	 * If the server doesn't advertise CAP_LARGE_READ_X, then assume that
+	 * it can't handle a read request larger than its MaxBufferSize either.
+	 */
+	if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_READ_CAP))
+		defsize = CIFS_DEFAULT_IOSIZE;
+	else if (server->capabilities & CAP_LARGE_READ_X)
+		defsize = CIFS_DEFAULT_NON_POSIX_RSIZE;
+	else
+		defsize = server->maxBuf - sizeof(READ_RSP);
+
+	rsize = volume_info->rsize ? volume_info->rsize : defsize;
+
+	/*
+	 * no CAP_LARGE_READ_X? Then MS-CIFS states that we must limit this to
+	 * the client's MaxBufferSize.
+	 */
+	if (!(server->capabilities & CAP_LARGE_READ_X))
+		rsize = min_t(unsigned int, CIFSMaxBufSize, rsize);
+
+	/* limit to the amount that we can kmap at once */
+	rsize = min_t(unsigned int, rsize, CIFS_KMAP_SIZE_LIMIT);
+
+	/* hard limit of CIFS_MAX_RSIZE */
+	rsize = min_t(unsigned int, rsize, CIFS_MAX_RSIZE);
+
+	return rsize;
+}
+
 static void
 cifs_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
 {
@@ -678,6 +762,8 @@ struct smb_version_operations smb1_operations = {
 	.check_trans2 = cifs_check_trans2,
 	.need_neg = cifs_need_neg,
 	.negotiate = cifs_negotiate,
+	.negotiate_wsize = cifs_negotiate_wsize,
+	.negotiate_rsize = cifs_negotiate_rsize,
 	.sess_setup = CIFS_SessSetup,
 	.logoff = CIFSSMBLogoff,
 	.tree_connect = CIFSTCon,