[CIFS] on reconnect to Samba - reset the unix capabilities

After temporary server or network failure and reconneciton, we were not
resending the unix capabilities via SetFSInfo - which confused Samba posix
byte range locking code.

Discovered by jra

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 86 insertions, 44 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 2caca06b4bae..20ba7dcc9959 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1613,6 +1613,76 @@ ipv6_connect(struct sockaddr_in6 *psin_server, struct socket **csocket)
         return rc;
 }
 
+void reset_cifs_unix_caps(int xid, struct cifsTconInfo * tcon, 
+                          struct super_block * sb, struct smb_vol * vol_info)
+{
+        /* if we are reconnecting then should we check to see if
+         * any requested capabilities changed locally e.g. via
+         * remount but we can not do much about it here
+         * if they have (even if we could detect it by the following)
+         * Perhaps we could add a backpointer to array of sb from tcon
+         * or if we change to make all sb to same share the same
+         * sb as NFS - then we only have one backpointer to sb.
+         * What if we wanted to mount the server share twice once with
+         * and once without posixacls or posix paths? */
+        __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+           
+         
+        if(!CIFSSMBQFSUnixInfo(xid, tcon)) {
+                __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+                
+                /* check for reconnect case in which we do not
+                   want to change the mount behavior if we can avoid it */
+                if(vol_info == NULL) {
+                        /* turn off POSIX ACL and PATHNAMES if not set 
+                           originally at mount time */
+                        if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
+                                cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
+                        if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0)
+                                cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
+                                
+
+                         
+                        
+                }
+                
+                cap &= CIFS_UNIX_CAP_MASK;
+                if(vol_info && vol_info->no_psx_acl)
+                        cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
+                else if(CIFS_UNIX_POSIX_ACL_CAP & cap) {
+                        cFYI(1,("negotiated posix acl support"));
+                        if(sb)
+                                sb->s_flags |= MS_POSIXACL;
+                }
+
+                if(vol_info && vol_info->posix_paths == 0)
+                        cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
+                else if(cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
+                        cFYI(1,("negotiate posix pathnames"));
+                        if(sb)
+                                CIFS_SB(sb)->mnt_cifs_flags |= 
+                                        CIFS_MOUNT_POSIX_PATHS;
+                }
+                        
+                cFYI(1,("Negotiate caps 0x%x",(int)cap));
+#ifdef CONFIG_CIFS_DEBUG2
+                if(cap & CIFS_UNIX_FCNTL_CAP)
+                        cFYI(1,("FCNTL cap"));
+                if(cap & CIFS_UNIX_EXTATTR_CAP)
+                        cFYI(1,("EXTATTR cap"));
+                if(cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
+                        cFYI(1,("POSIX path cap"));
+                if(cap & CIFS_UNIX_XATTR_CAP)
+                        cFYI(1,("XATTR cap"));
+                if(cap & CIFS_UNIX_POSIX_ACL_CAP)
+                        cFYI(1,("POSIX ACL cap"));
+#endif /* CIFS_DEBUG2 */
+                if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
+                        cFYI(1,("setting capabilities failed"));
+                }
+        }
+}
+
 int
 cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
            char *mount_data, const char *devname)
@@ -1928,20 +1998,25 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
                         if (tcon == NULL)
                                 rc = -ENOMEM;
                         else {
-                                /* check for null share name ie connect to dfs root */
+                                /* check for null share name ie connecting to 
+                                 * dfs root */
 
-                                /* BB check if this works for exactly length three strings */
+                                /* BB check if this works for exactly length 
+                                 * three strings */
                                 if ((strchr(volume_info.UNC + 3, '\\') == NULL)
                                     && (strchr(volume_info.UNC + 3, '/') ==
                                         NULL)) {
                                         rc = connect_to_dfs_path(xid, pSesInfo,
-                                                        "", cifs_sb->local_nls,
-                                                        cifs_sb->mnt_cifs_flags & 
-                                                          CIFS_MOUNT_MAP_SPECIAL_CHR);
+                                                "", cifs_sb->local_nls,
+                                                cifs_sb->mnt_cifs_flags & 
+                                                  CIFS_MOUNT_MAP_SPECIAL_CHR);
                                         kfree(volume_info.UNC);
                                         FreeXid(xid);
                                         return -ENODEV;
                                 } else {
+                                        /* BB Do we need to wrap sesSem around
+                                         * this TCon call and Unix SetFS as
+                                         * we do on SessSetup and reconnect? */
                                         rc = CIFSTCon(xid, pSesInfo, 
                                                 volume_info.UNC,
                                                 tcon, cifs_sb->local_nls);
@@ -1962,6 +2037,7 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
                         sb->s_maxbytes = (u64) 1 << 31; /* 2 GB */
         }
 
+        /* BB FIXME fix time_gran to be larger for LANMAN sessions */
         sb->s_time_gran = 100;
 
 /* on error free sesinfo and tcon struct if needed */
@@ -2006,45 +2082,11 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
                 /* do not care if following two calls succeed - informational */
                 CIFSSMBQFSDeviceInfo(xid, tcon);
                 CIFSSMBQFSAttributeInfo(xid, tcon);
-
-                if (tcon->ses->capabilities & CAP_UNIX) {
-                        if(!CIFSSMBQFSUnixInfo(xid, tcon)) {
-                                __u64 cap = 
-                                       le64_to_cpu(tcon->fsUnixInfo.Capability);
-                                cap &= CIFS_UNIX_CAP_MASK;
-                                if(volume_info.no_psx_acl)
-                                        cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
-                                else if(CIFS_UNIX_POSIX_ACL_CAP & cap) {
-                                        cFYI(1,("negotiated posix acl support"));
-                                        sb->s_flags |= MS_POSIXACL;
-                                }
-
-                                if(volume_info.posix_paths == 0)
-                                        cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
-                                else if(cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
-                                        cFYI(1,("negotiate posix pathnames"));
-                                        cifs_sb->mnt_cifs_flags |= 
-                                                CIFS_MOUNT_POSIX_PATHS;
-                                }
-                                        
-                                cFYI(1,("Negotiate caps 0x%x",(int)cap));
-#ifdef CONFIG_CIFS_DEBUG2
-                                if(cap & CIFS_UNIX_FCNTL_CAP)
-                                        cFYI(1,("FCNTL cap"));
-                                if(cap & CIFS_UNIX_EXTATTR_CAP)
-                                        cFYI(1,("EXTATTR cap"));
-                                if(cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
-                                        cFYI(1,("POSIX path cap"));
-                                if(cap & CIFS_UNIX_XATTR_CAP)
-                                        cFYI(1,("XATTR cap"));
-                                if(cap & CIFS_UNIX_POSIX_ACL_CAP)
-                                        cFYI(1,("POSIX ACL cap"));
-#endif /* CIFS_DEBUG2 */
-                                if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
-                                        cFYI(1,("setting capabilities failed"));
-                                }
-                        }
-                }
+                
+                /* tell server which Unix caps we support */
+                if (tcon->ses->capabilities & CAP_UNIX)
+                        reset_cifs_unix_caps(xid, tcon, sb, &volume_info);
+                
                 if (!(tcon->ses->capabilities & CAP_LARGE_WRITE_X))
                         cifs_sb->wsize = min(cifs_sb->wsize,
                                              (tcon->ses->server->maxBuf -