[CIFS] Fix paths when share is in DFS to include proper prefix

Some versions of Samba (3.2-pre e.g.) are stricter about checking to make sure that
paths in DFS name spaces are sent in the form \\server\share\dir\subdir ...
instead of \dir\subdir

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

5 files changed, 37 insertions, 127 deletions

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 08248e85b788..845b18e1abe5 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -150,9 +150,6 @@ extern int CIFSGetDFSRefer(const int xid, struct cifsSesInfo *ses,
                         unsigned int *number_of_UNC_in_array,
                         const struct nls_table *nls_codepage, int remap);
 
-extern int connect_to_dfs_path(int xid, struct cifsSesInfo *pSesInfo,
-                        const char *old_path,
-                        const struct nls_table *nls_codepage, int remap);
 extern int get_dfs_path(int xid, struct cifsSesInfo *pSesInfo,
                         const char *old_path,
                         const struct nls_table *nls_codepage,
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 7c2e5ea03305..d5747e30f1c9 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1419,27 +1419,6 @@ find_unc(__be32 new_target_ip_addr, char *uncName, char *userName)
 }
 
 int
-connect_to_dfs_path(int xid, struct cifsSesInfo *pSesInfo,
-                    const char *old_path, const struct nls_table *nls_codepage,
-                    int remap)
-{
-        struct dfs_info3_param *referrals = NULL;
-        unsigned int num_referrals;
-        int rc = 0;
-
-        rc = get_dfs_path(xid, pSesInfo, old_path, nls_codepage,
-                        &num_referrals, &referrals, remap);
-
-        /* BB Add in code to: if valid refrl, if not ip address contact
-                the helper that resolves tcp names, mount to it, try to
-                tcon to it unmount it if fail */
-
-        kfree(referrals);
-
-        return rc;
-}
-
-int
 get_dfs_path(int xid, struct cifsSesInfo *pSesInfo, const char *old_path,
              const struct nls_table *nls_codepage, unsigned int *pnum_referrals,
              struct dfs_info3_param **preferrals, int remap)
@@ -2161,10 +2140,11 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
                                 if ((strchr(volume_info.UNC + 3, '\\') == NULL)
                                     && (strchr(volume_info.UNC + 3, '/') ==
                                         NULL)) {
-                                        rc = connect_to_dfs_path(xid, pSesInfo,
+/*                                      rc = connect_to_dfs_path(xid, pSesInfo,
                                                 "", cifs_sb->local_nls,
                                                 cifs_sb->mnt_cifs_flags &
-                                                  CIFS_MOUNT_MAP_SPECIAL_CHR);
+                                                  CIFS_MOUNT_MAP_SPECIAL_CHR);*/
+                                        cFYI(1, ("DFS root not supported"));
                                         rc = -ENODEV;
                                         goto out;
                                 } else {
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index e4e0078a0526..05afe33ea644 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -49,18 +49,25 @@ build_path_from_dentry(struct dentry *direntry)
         struct dentry *temp;
         int namelen;
         int pplen;
+        int dfsplen;
         char *full_path;
         char dirsep;
+        struct cifs_sb_info *cifs_sb;
 
         if (direntry == NULL)
                 return NULL;  /* not much we can do if dentry is freed and
                 we need to reopen the file after it was closed implicitly
                 when the server crashed */
 
-        dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
-        pplen = CIFS_SB(direntry->d_sb)->prepathlen;
+        cifs_sb = CIFS_SB(direntry->d_sb);
+        dirsep = CIFS_DIR_SEP(cifs_sb);
+        pplen = cifs_sb->prepathlen;
+        if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
+                dfsplen = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE + 1);
+        else
+                dfsplen = 0;
 cifs_bp_rename_retry:
-        namelen = pplen;
+        namelen = pplen + dfsplen;
         for (temp = direntry; !IS_ROOT(temp);) {
                 namelen += (1 + temp->d_name.len);
                 temp = temp->d_parent;
@@ -91,7 +98,7 @@ cifs_bp_rename_retry:
                         return NULL;
                 }
         }
-        if (namelen != pplen) {
+        if (namelen != pplen + dfsplen) {
                 cERROR(1,
                        ("did not end path lookup where expected namelen is %d",
                         namelen));
@@ -107,7 +114,18 @@ cifs_bp_rename_retry:
            since the '\' is a valid posix character so we can not switch
            those safely to '/' if any are found in the middle of the prepath */
         /* BB test paths to Windows with '/' in the midst of prepath */
-        strncpy(full_path, CIFS_SB(direntry->d_sb)->prepath, pplen);
+
+        if (dfsplen) {
+                strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
+                if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
+                        int i;
+                        for (i = 0; i < dfsplen; i++) {
+                                if (full_path[i] == '\\')
+                                        full_path[i] = '/';
+                        }
+                }
+        }
+        strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
         return full_path;
 }
 
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 2d53b436d511..9d9b56a9c08e 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -161,52 +161,18 @@ static void cifs_unix_info_to_inode(struct inode *inode,
         spin_unlock(&inode->i_lock);
 }
 
-static const unsigned char *cifs_get_search_path(struct cifs_sb_info *cifs_sb,
-                                                const char *search_path)
-{
-        int tree_len;
-        int path_len;
-        int i;
-        char *tmp_path;
-        struct cifsTconInfo *pTcon = cifs_sb->tcon;
-
-        if (!(pTcon->Flags & SMB_SHARE_IS_IN_DFS))
-                return search_path;
-
-        /* use full path name for working with DFS */
-        tree_len = strnlen(pTcon->treeName, MAX_TREE_SIZE + 1);
-        path_len = strnlen(search_path, MAX_PATHCONF);
-
-        tmp_path = kmalloc(tree_len+path_len+1, GFP_KERNEL);
-        if (tmp_path == NULL)
-                return search_path;
-
-        strncpy(tmp_path, pTcon->treeName, tree_len);
-        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
-                for (i = 0; i < tree_len; i++) {
-                        if (tmp_path[i] == '\\')
-                                tmp_path[i] = '/';
-                }
-        strncpy(tmp_path+tree_len, search_path, path_len);
-        tmp_path[tree_len+path_len] = 0;
-        return tmp_path;
-}
-
 int cifs_get_inode_info_unix(struct inode **pinode,
-        const unsigned char *search_path, struct super_block *sb, int xid)
+        const unsigned char *full_path, struct super_block *sb, int xid)
 {
         int rc = 0;
         FILE_UNIX_BASIC_INFO findData;
         struct cifsTconInfo *pTcon;
         struct inode *inode;
         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-        const unsigned char *full_path;
         bool is_dfs_referral = false;
 
         pTcon = cifs_sb->tcon;
-        cFYI(1, ("Getting info on %s", search_path));
-
-        full_path = cifs_get_search_path(cifs_sb, search_path);
+        cFYI(1, ("Getting info on %s", full_path));
 
 try_again_CIFSSMBUnixQPathInfo:
         /* could have done a find first instead but this returns more info */
@@ -218,10 +184,6 @@ try_again_CIFSSMBUnixQPathInfo:
         if (rc) {
                 if (rc == -EREMOTE && !is_dfs_referral) {
                         is_dfs_referral = true;
-                        if (full_path != search_path) {
-                                kfree(full_path);
-                                full_path = search_path;
-                        }
                         goto try_again_CIFSSMBUnixQPathInfo;
                 }
                 goto cgiiu_exit;
@@ -271,8 +233,6 @@ try_again_CIFSSMBUnixQPathInfo:
                 cifs_set_ops(inode, is_dfs_referral);
         }
 cgiiu_exit:
-        if (full_path != search_path)
-                kfree(full_path);
         return rc;
 }
 
@@ -380,20 +340,19 @@ static int get_sfu_mode(struct inode *inode,
 }
 
 int cifs_get_inode_info(struct inode **pinode,
-        const unsigned char *search_path, FILE_ALL_INFO *pfindData,
+        const unsigned char *full_path, FILE_ALL_INFO *pfindData,
         struct super_block *sb, int xid, const __u16 *pfid)
 {
         int rc = 0;
         struct cifsTconInfo *pTcon;
         struct inode *inode;
         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-        const unsigned char *full_path = NULL;
         char *buf = NULL;
         bool adjustTZ = false;
         bool is_dfs_referral = false;
 
         pTcon = cifs_sb->tcon;
-        cFYI(1, ("Getting info on %s", search_path));
+        cFYI(1, ("Getting info on %s", full_path));
 
         if ((pfindData == NULL) && (*pinode != NULL)) {
                 if (CIFS_I(*pinode)->clientCanCacheRead) {
@@ -409,8 +368,6 @@ int cifs_get_inode_info(struct inode **pinode,
                         return -ENOMEM;
                 pfindData = (FILE_ALL_INFO *)buf;
 
-                full_path = cifs_get_search_path(cifs_sb, search_path);
-
 try_again_CIFSSMBQPathInfo:
                 /* could do find first instead but this returns more info */
                 rc = CIFSSMBQPathInfo(xid, pTcon, full_path, pfindData,
@@ -432,10 +389,6 @@ try_again_CIFSSMBQPathInfo:
         if (rc) {
                 if (rc == -EREMOTE && !is_dfs_referral) {
                         is_dfs_referral = true;
-                        if (full_path != search_path) {
-                                kfree(full_path);
-                                full_path = search_path;
-                        }
                         goto try_again_CIFSSMBQPathInfo;
                 }
                 goto cgii_exit;
@@ -470,7 +423,7 @@ try_again_CIFSSMBQPathInfo:
                                 __u64 inode_num;
 
                                 rc1 = CIFSGetSrvInodeNumber(xid, pTcon,
-                                        search_path, &inode_num,
+                                        full_path, &inode_num,
                                         cifs_sb->local_nls,
                                         cifs_sb->mnt_cifs_flags &
                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -539,7 +492,7 @@ try_again_CIFSSMBQPathInfo:
                            (cifsInfo->cifsAttrs & ATTR_SYSTEM)) {
                         if (decode_sfu_inode(inode,
                                          le64_to_cpu(pfindData->EndOfFile),
-                                         search_path,
+                                         full_path,
                                          cifs_sb, xid))
                                 cFYI(1, ("Unrecognized sfu inode type"));
 
@@ -582,12 +535,12 @@ try_again_CIFSSMBQPathInfo:
                 /* fill in 0777 bits from ACL */
                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
                         cFYI(1, ("Getting mode bits from ACL"));
-                        acl_to_uid_mode(inode, search_path, pfid);
+                        acl_to_uid_mode(inode, full_path, pfid);
                 }
 #endif
                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
                         /* fill in remaining high mode bits e.g. SUID, VTX */
-                        get_sfu_mode(inode, search_path, cifs_sb, xid);
+                        get_sfu_mode(inode, full_path, cifs_sb, xid);
                 } else if (atomic_read(&cifsInfo->inUse) == 0) {
                         inode->i_uid = cifs_sb->mnt_uid;
                         inode->i_gid = cifs_sb->mnt_gid;
@@ -599,8 +552,6 @@ try_again_CIFSSMBQPathInfo:
                 cifs_set_ops(inode, is_dfs_referral);
         }
 cgii_exit:
-        if (full_path != search_path)
-                kfree(full_path);
         kfree(buf);
         return rc;
 }
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 1c2c3ce5020b..316f9830ce3b 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -295,45 +295,9 @@ cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
                                 cFYI(1, ("Error closing junction point "
                                          "(open for ioctl)"));
                         }
-                        /* BB unwind this long, nested function, or remove BB */
-                        if (rc == -EIO) {
-                                /* Query if DFS Junction */
-                                unsigned int num_referrals = 0;
-                                struct dfs_info3_param *refs = NULL;
-                                tmp_path =
-                                        kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
-                                                GFP_KERNEL);
-                                if (tmp_path) {
-                                        strncpy(tmp_path, pTcon->treeName,
-                                                MAX_TREE_SIZE);
-                                        strncat(tmp_path, full_path,
-                                                MAX_PATHCONF);
-                                        rc = get_dfs_path(xid, pTcon->ses,
-                                                tmp_path,
-                                                cifs_sb->local_nls,
-                                                &num_referrals, &refs,
-                                                cifs_sb->mnt_cifs_flags &
-                                                    CIFS_MOUNT_MAP_SPECIAL_CHR);
-                                        cFYI(1, ("Get DFS for %s rc = %d ",
-                                                tmp_path, rc));
-                                        if ((num_referrals == 0) && (rc == 0))
-                                                rc = -EACCES;
-                                        else {
-                                                cFYI(1, ("num referral: %d",
-                                                        num_referrals));
-                                                if (refs && refs->path_name) {
-                                                        strncpy(tmpbuffer,
-                                                                refs->path_name,
-                                                                len-1);
-                                                }
-                                        }
-                                        kfree(refs);
-                                        kfree(tmp_path);
-}
-                                /* BB add code like else decode referrals
-                                then memcpy to tmpbuffer and free referrals
-                                string array BB */
-                        }
+                        /* If it is a DFS junction earlier we would have gotten
+                           PATH_NOT_COVERED returned from server so we do
+                           not need to request the DFS info here */
                 }
         }
         /* BB Anything else to do to handle recursive links? */