1 files changed, 86 insertions, 0 deletions

diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index df20dd9e64ca..7e8a2bdd69c8 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,