Fix oops in getdfs when null path passed in on mount. Fix oops when changed...

Fix oops in getdfs when null path passed in on mount.  Fix oops when changed readsize caused readpages problem.  Add support for altering rsize so can reduce pages read across net
below default of 4

fs/cifs/CHANGES

+Version 0.70
+------------
+Fix oops in get dfs referral (triggered when null path sent in to
+mount).  Add support for overriding rsize at mount time.
+
 Version 0.69
 ------------
 Fix buffer overrun in readdir which caused intermittent kernel oopses.

fs/cifs/TODO

@@ -42,13 +42,24 @@ extra copy in/out of the socket buffers in some cases.
 
 m) finish support for IPv6
 
-KNOWN BUGS (updated February 15, 2003)
+n) send oplock break response when sent (oplock currently disabled in
+/proc/fs/cifs)
+
+o) remove calls to set end of file by name when we already have file open
+(use the existing handle since some servers only support that and it
+reduces the oplock breaks coming from windows).  Piggyback identical
+file opens on top of each other by incrementing reference count rather
+than resending (helps reduce server resource utilization and avoid
+spurious oplock breaks).
+
+KNOWN BUGS (updated March 7, 2003)
 ====================================
 1) existing symbolic links (Windows reparse points) are recognized but
 can not be created remotely. They are implemented for Samba and those that
 support the CIFS Unix extensions but Samba has a bug currently handling
 symlink text beginning with slash
 2) delete of file with read-only attribute set will fail (may be ok)
+3) mount helper syntax not quite matching man page
 
 Misc testing to do
 =================

fs/cifs/cifs_debug.c

@@ -227,7 +227,7 @@ cifs_proc_init(void)
 	if (pde)
 		pde->write_proc = traceSMB_write;
 
-	pde = create_proc_read_entry("oplockEnabled", 0, proc_fs_cifs,
+	pde = create_proc_read_entry("OplockEnabled", 0, proc_fs_cifs,
 				     oplockEnabled_read, 0);
 	if (pde)
 		pde->write_proc = oplockEnabled_write;
@@ -269,7 +269,7 @@ cifs_proc_clean(void)
 	remove_proc_entry("SimultaneousOps", proc_fs_cifs);
 	remove_proc_entry("TotalOps", proc_fs_cifs);
 	remove_proc_entry("MultiuserMount", proc_fs_cifs);
-	remove_proc_entry("oplockEnabled", proc_fs_cifs);
+	remove_proc_entry("OplockEnabled", proc_fs_cifs);
 	remove_proc_entry("NTLMV2Enabled",proc_fs_cifs);
 	remove_proc_entry("ExtendedSecurity",proc_fs_cifs);
 	remove_proc_entry("PacketSigningEnabled",proc_fs_cifs);

fs/cifs/cifs_fs_sb.h

@@ -20,8 +20,9 @@
 
 struct cifs_sb_info {
 	struct cifsTconInfo *tcon;	/* primary mount */
-	/* list of implicit mounts beneath this mount point - needed in dfs case */
 	struct list_head nested_tcon_q;
 	struct nls_table *local_nls;
+    unsigned int rsize;
+    unsigned int wsize;
 };
 #endif				/* _CIFS_FS_SB_H */

fs/cifs/cifsfs.c

@@ -52,6 +52,7 @@ unsigned int multiuser_mount = 0;
 unsigned int extended_security = 0;
 unsigned int ntlmv2_support = 0;
 unsigned int sign_CIFS_PDUs = 0;
+unsigned int CIFSMaximumBufferSize = CIFS_MAX_MSGSIZE;
 
 extern int cifs_mount(struct super_block *, struct cifs_sb_info *, char *,
 			char *);
@@ -83,8 +84,11 @@ cifs_read_super(struct super_block *sb, void *data, char *devname, int silent)
 
 	sb->s_magic = CIFS_MAGIC_NUMBER;
 	sb->s_op = &cifs_super_ops;
-	sb->s_blocksize = CIFS_MAX_MSGSIZE;	/* BB check SMBSessSetup negotiated size */
-	sb->s_blocksize_bits = 10;	/* 2**10 = CIFS_MAX_MSGSIZE */
+	if(cifs_sb->tcon->ses->server->maxBuf > MAX_CIFS_HDR_SIZE + 512)
+	    sb->s_blocksize = cifs_sb->tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE;
+	else
+		sb->s_blocksize = CIFSMaximumBufferSize;
+	sb->s_blocksize_bits = 14;	/* default 2**14 = CIFS_MAX_MSGSIZE */
 	inode = iget(sb, ROOT_I);
 
 	if (!inode)
@@ -162,6 +166,12 @@ cifs_statfs(struct super_block *sb, struct statfs *buf)
 	return 0;		/* always return success? what if volume is no longer available? */
 }
 
+static int cifs_permission(struct inode * inode, int mask)
+{
+	/* the server does permission checks, we do not need to do it here */
+	return 0;
+}
+
 static kmem_cache_t *cifs_inode_cachep;
 kmem_cache_t *cifs_req_cachep;
 kmem_cache_t *cifs_mid_cachep;
@@ -270,6 +280,7 @@ struct inode_operations cifs_dir_inode_ops = {
 	.mkdir = cifs_mkdir,
 	.rmdir = cifs_rmdir,
 	.rename = cifs_rename,
+	.permission = cifs_permission,
 /*	revalidate:cifs_revalidate,   */
 	.setattr = cifs_setattr,
 	.symlink = cifs_symlink,
@@ -280,18 +291,19 @@ struct inode_operations cifs_file_inode_ops = {
 	.setattr = cifs_setattr,
 	.getattr = cifs_getattr, /* do we need this anymore? */
 	.rename = cifs_rename,
+	.permission = cifs_permission,
 #ifdef CIFS_XATTR
 	.setxattr = cifs_setxattr,
 	.getxattr = cifs_getxattr,
 	.listxattr = cifs_listxattr,
 	.removexattr = cifs_removexattr,
-	.permission = cifs_permission,
 #endif 
 };
 
 struct inode_operations cifs_symlink_inode_ops = {
 	.readlink = cifs_readlink,
 	.follow_link = cifs_follow_link,
+	.permission = cifs_permission,
 	/* BB add the following two eventually */
 	/* revalidate: cifs_revalidate,
 	   setattr:    cifs_notify_change, *//* BB do we need notify change */

fs/cifs/cifssmb.c

@@ -519,8 +519,7 @@ CIFSSMBRead(const int xid, struct cifsTconInfo *tcon,
 	pSMB->OffsetLow = cpu_to_le32(lseek & 0xFFFFFFFF);
 	pSMB->OffsetHigh = cpu_to_le32(lseek >> 32);
 	pSMB->Remaining = 0;
-	pSMB->MaxCount = cpu_to_le16(min_t(const unsigned int, count,
-		(tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE) & 0xFFFFFF00));
+	pSMB->MaxCount = cpu_to_le16(count);
 	pSMB->MaxCountHigh = 0;
 	pSMB->ByteCount = 0;  /* no need to do le conversion since it is 0 */
 

fs/cifs/connect.c

@@ -25,6 +25,7 @@
 #include <linux/wait.h>
 #include <linux/version.h>
 #include <linux/ipv6.h>
+#include <linux/pagemap.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 #include "cifspdu.h"
@@ -56,6 +57,8 @@ struct smb_vol {
 	mode_t file_mode;
 	mode_t dir_mode;
 	int rw;
+    unsigned int rsize;
+    unsigned int wsize;
 	unsigned short int port;
 };
 
@@ -447,6 +450,16 @@ parse_mount_options(char *options, char *devname, struct smb_vol *vol)
 				vol->port =
 					simple_strtoul(value, &value, 0);
 			}
+		} else if (strnicmp(data, "rsize", 5) == 0) {
+			if (value && *value) {
+				vol->rsize =
+					simple_strtoul(value, &value, 0);
+			}
+		} else if (strnicmp(data, "wsize", 5) == 0) {
+			if (value && *value) {
+				vol->wsize =
+					simple_strtoul(value, &value, 0);
+			}
 		} else if (strnicmp(data, "version", 3) == 0) {
 			/* ignore */
 		} else if (strnicmp(data, "rw", 2) == 0) {
@@ -573,11 +586,8 @@ connect_to_dfs_path(int xid, struct cifsSesInfo *pSesInfo,
 			return -ENOMEM;
 		temp_unc[0] = '\\';
 		temp_unc[1] = '\\';
-		strncpy(temp_unc + 2, pSesInfo->serverName,
-			SERVER_NAME_LEN_WITH_NULL * 2);
-		strncpy(temp_unc + 2 + 
-			strnlen(pSesInfo->serverName,SERVER_NAME_LEN_WITH_NULL * 2), 
-			"\\IPC$", 5);
+		strcpy(temp_unc + 2, pSesInfo->serverName);
+		strcpy(temp_unc + 2 + strlen(pSesInfo->serverName), "\\IPC$");
 		rc = CIFSTCon(xid, pSesInfo, temp_unc, NULL, nls_codepage);
 		cFYI(1,
 		     ("CIFS Tcon rc = %d ipc_tid = %d", rc,pSesInfo->ipc_tid));
@@ -598,6 +608,7 @@ int setup_session(unsigned int xid, struct cifsSesInfo *pSesInfo, struct nls_tab
 	char ntlm_session_key[CIFS_SESSION_KEY_SIZE];
 	int ntlmv2_flag = FALSE;
 
+    /* what if server changes its buffer size after dropping the session? */
 	if(pSesInfo->server->maxBuf == 0) /* no need to send on reconnect */
 		rc = CIFSSMBNegotiate(xid, pSesInfo);
 	pSesInfo->capabilities = pSesInfo->server->capabilities;
@@ -778,7 +789,7 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 	struct TCP_Server_Info *srvTcp = NULL;
 
 	xid = GetXid();
-	cFYI(0, ("Entering cifs_mount. Xid: %d with: %s", xid, mount_data));
+	cFYI(1, ("Entering cifs_mount. Xid: %d with: %s", xid, mount_data));
 
 	if(parse_mount_options(mount_data, devname, &volume_info)) {
 		FreeXid(xid);
@@ -875,9 +886,23 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 				atomic_inc(&srvTcp->socketUseCount);
 		}
 	}
-
+    
 	/* search for existing tcon to this server share */
 	if (!rc) {
+		if((volume_info.rsize) && (volume_info.rsize + MAX_CIFS_HDR_SIZE < srvTcp->maxBuf))
+			cifs_sb->rsize = volume_info.rsize;
+		else
+			cifs_sb->rsize = srvTcp->maxBuf - MAX_CIFS_HDR_SIZE; /* default */
+		if((volume_info.wsize) && (volume_info.wsize + MAX_CIFS_HDR_SIZE < srvTcp->maxBuf))
+			cifs_sb->wsize = volume_info.wsize;
+		else
+			cifs_sb->wsize = srvTcp->maxBuf - MAX_CIFS_HDR_SIZE; /* default */
+		if(cifs_sb->rsize < PAGE_CACHE_SIZE) {
+			cifs_sb->rsize = PAGE_CACHE_SIZE;
+			cERROR(1,("Attempt to set readsize for mount to less than one page (4096)"));
+		}
+
+
 		tcon =
 		    find_unc(sin_server.sin_addr.s_addr, volume_info.UNC,
 			     volume_info.username);
@@ -980,7 +1005,7 @@ CIFSSessSetup(unsigned int xid, struct cifsSesInfo *ses,
 	if (smb_buffer == 0) {
 		return -ENOMEM;
 	}
-    smb_buffer_response = smb_buffer;
+	smb_buffer_response = smb_buffer;
 	pSMBr = pSMB = (SESSION_SETUP_ANDX *) smb_buffer;
 
 	/* send SMBsessionSetup here */

fs/cifs/file.c

@@ -608,6 +608,7 @@ cifs_read(struct file * file, char *read_data, size_t read_size,
 	int rc = -EACCES;
 	int bytes_read = 0;
 	int total_read;
+	int current_read_size;
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;
 	int xid;
@@ -624,10 +625,11 @@ cifs_read(struct file * file, char *read_data, size_t read_size,
 
 	for (total_read = 0,current_offset=read_data; read_size > total_read;
 				total_read += bytes_read,current_offset+=bytes_read) {
+		current_read_size = min_t(const int,read_size - total_read,cifs_sb->rsize);
 		rc = CIFSSMBRead(xid, pTcon,
 				 ((struct cifsFileInfo *) file->
 				  private_data)->netfid,
-				 read_size - total_read, *poffset,
+				 current_read_size, *poffset,
 				 &bytes_read, &current_offset);
 		if (rc || (bytes_read == 0)) {
 			if (total_read) {
@@ -744,6 +746,8 @@ cifs_readpages(struct file *file, struct address_space *mapping,
 			num_pages-i, (unsigned long) offset)); 
 		
 		read_size = (num_pages - i) * PAGE_CACHE_SIZE;
+		/* Read size needs to be in multiples of one page */
+		read_size = min_t(const unsigned int,read_size,cifs_sb->rsize & PAGE_CACHE_MASK);
 		rc = CIFSSMBRead(xid, pTcon,
 			((struct cifsFileInfo *) file->
 			 private_data)->netfid,

fs/cifs/misc.c

@@ -153,7 +153,8 @@ buf_get(void)
 
 /* We could use negotiated size instead of max_msgsize - 
    but it may be more efficient to always alloc same size 
-   albeit slightly larger */
+   albeit slightly larger than necessary and maxbuffersize 
+   defaults to this and can not be bigger */
 	ret_buf =
 	    (struct smb_hdr *) kmem_cache_alloc(cifs_req_cachep, SLAB_KERNEL);
 

fs/cifs/transport.c

@@ -159,7 +159,7 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 	midQ = AllocMidQEntry(in_buf, ses);
 	if (midQ == NULL)
 		return -EIO;
-	if (in_buf->smb_buf_length > CIFS_MAX_MSGSIZE + MAX_CIFS_HDR_SIZE) {
+	if (in_buf->smb_buf_length > CIFS_MAX_MSGSIZE + MAX_CIFS_HDR_SIZE - 4) {
 		cERROR(1,
 		       ("Illegal length, greater than maximum frame, %d ",
 			in_buf->smb_buf_length));