[CIFS] Add support for readdir to legacy servers

Fixes oops to OS/2 on ls and removes redundant NTCreateX calls to servers
which do not support NT SMBs.  Key operations to OS/2 work.
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/CHANGES

@@ -2,6 +2,10 @@ Version 1.44
 ------------
 Rewritten sessionsetup support, including support for legacy SMB
 session setup needed for OS/2 and older servers such as Windows 95 and 98.
+Fix oops on ls to OS/2 servers.  Add support for level 1 FindFirst
+so we can do search (ls etc.) to OS/2.  Do not send NTCreateX
+or recent levels of FindFirst unless server says it supports NT SMBs
+(instead use legacy equivalents from LANMAN dialect).
 
 Version 1.43
 ------------

fs/cifs/cifspdu.h

@@ -1374,6 +1374,9 @@ struct smb_t2_rsp {
 #define SMB_FILE_MAXIMUM_INFO           0x40d
 
 /* Find File infolevels */
+#define SMB_FIND_FILE_INFO_STANDARD       0x001
+#define SMB_FIND_FILE_QUERY_EA_SIZE       0x002
+#define SMB_FIND_FILE_QUERY_EAS_FROM_LIST 0x003
 #define SMB_FIND_FILE_DIRECTORY_INFO      0x101
 #define SMB_FIND_FILE_FULL_DIRECTORY_INFO 0x102
 #define SMB_FIND_FILE_NAMES_INFO          0x103
@@ -1998,7 +2001,8 @@ typedef struct {
 
 struct file_allocation_info {
 	__le64 AllocationSize; /* Note old Samba srvr rounds this up too much */
-} __attribute__((packed));	/* size used on disk, level 0x103 for set, 0x105 for query */
+} __attribute__((packed));	/* size used on disk, for level 0x103 for set,
+				   0x105 for query */
 
 struct file_end_of_file_info {
 	__le64 FileSize;		/* offset to end of file */
@@ -2105,7 +2109,7 @@ typedef struct {
 	__le32 ExtFileAttributes;
 	__le32 FileNameLength;
 	char FileName[1];
-} __attribute__((packed)) FILE_DIRECTORY_INFO;   /* level 0x101 FF response data area */
+} __attribute__((packed)) FILE_DIRECTORY_INFO;   /* level 0x101 FF resp data */
 
 typedef struct {
 	__le32 NextEntryOffset;
@@ -2120,7 +2124,7 @@ typedef struct {
 	__le32 FileNameLength;
 	__le32 EaSize; /* length of the xattrs */
 	char FileName[1];
-} __attribute__((packed)) FILE_FULL_DIRECTORY_INFO;   /* level 0x102 FF response data area */
+} __attribute__((packed)) FILE_FULL_DIRECTORY_INFO; /* level 0x102 rsp data */
 
 typedef struct {
 	__le32 NextEntryOffset;
@@ -2137,7 +2141,7 @@ typedef struct {
 	__le32 Reserved;
 	__u64 UniqueId; /* inode num - le since Samba puts ino in low 32 bit*/
 	char FileName[1];
-} __attribute__((packed)) SEARCH_ID_FULL_DIR_INFO;   /* level 0x105 FF response data area */
+} __attribute__((packed)) SEARCH_ID_FULL_DIR_INFO; /* level 0x105 FF rsp data */
 
 typedef struct {
 	__le32 NextEntryOffset;
@@ -2155,7 +2159,22 @@ typedef struct {
 	__u8   Reserved;
 	__u8   ShortName[12];
 	char FileName[1];
-} __attribute__((packed)) FILE_BOTH_DIRECTORY_INFO;   /* level 0x104 FF response data area */
+} __attribute__((packed)) FILE_BOTH_DIRECTORY_INFO; /* level 0x104 FFrsp data */
+
+typedef struct {
+	__u32  ResumeKey;
+	__le16 CreationDate; /* SMB Date */
+	__le16 CreationTime; /* SMB Time */
+	__le16 LastAccessDate;
+	__le16 LastAccessTime;
+	__le16 LastWriteDate;
+	__le16 LastWriteTime;
+	__le32 DataSize; /* File Size (EOF) */
+	__le32 AllocationSize;
+	__le16 Attributes; /* verify not u32 */
+	__u8   FileNameLength;
+	char FileName[1];
+} __attribute__((packed)) FIND_FILE_STANDARD_INFO; /* level 0x1 FF resp data */
 
 
 struct win_dev {

fs/cifs/dir.c

@@ -178,11 +178,14 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 		FreeXid(xid);
 		return -ENOMEM;
 	}
-
+	if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS) 
 		rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 			 desiredAccess, CREATE_NOT_DIR,
 			 &fileHandle, &oplock, buf, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+	else
+		rc = -EIO; /* no NT SMB support fall into legacy open below */
+
 	if(rc == -EIO) {
 		/* old server, retry the open legacy style */
 		rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
@@ -369,6 +372,10 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
 					 cifs_sb->mnt_cifs_flags & 
 					    CIFS_MOUNT_MAP_SPECIAL_CHR);
 
+			/* BB FIXME - add handling for backlevel servers
+			   which need legacy open and check for all
+			   calls to SMBOpen for fallback to 
+			   SMBLeagcyOpen */
 			if(!rc) {
 				/* BB Do not bother to decode buf since no
 				   local inode yet to put timestamps in,

fs/cifs/file.c

@@ -260,10 +260,15 @@ int cifs_open(struct inode *inode, struct file *file)
 		rc = -ENOMEM;
 		goto out;
 	}
-	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
-			 CREATE_NOT_DIR, &netfid, &oplock, buf,
+
+	if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
+		rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, 
+			 desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 				 & CIFS_MOUNT_MAP_SPECIAL_CHR);
+	else
+		rc = -EIO; /* no NT SMB support fall into legacy open below */
+
 	if (rc == -EIO) {
 		/* Old server, try legacy style OpenX */
 		rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,