[CIFS] DFS patch that connects inode with dfs handling ops

 if DFS junction point

Signed-off-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 71 insertions, 62 deletions

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 24eb4d392155..4f0ee67eb954 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -30,7 +30,7 @@
 #include "cifs_fs_sb.h"
 
 
-static void cifs_set_ops(struct inode *inode)
+static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral)
 {
         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 
@@ -57,8 +57,12 @@ static void cifs_set_ops(struct inode *inode)
                         inode->i_data.a_ops = &cifs_addr_ops;
                 break;
         case S_IFDIR:
-                inode->i_op = &cifs_dir_inode_ops;
-                inode->i_fop = &cifs_dir_ops;
+                if (is_dfs_referral) {
+                        inode->i_op = &cifs_dfs_referral_inode_operations;
+                } else {
+                        inode->i_op = &cifs_dir_inode_ops;
+                        inode->i_fop = &cifs_dir_ops;
+                }
                 break;
         case S_IFLNK:
                 inode->i_op = &cifs_symlink_inode_ops;
@@ -153,6 +157,30 @@ static void cifs_unix_info_to_inode(struct inode *inode,
         spin_unlock(&inode->i_lock);
 }
 
+static const unsigned char *cifs_get_search_path(struct cifsTconInfo *pTcon,
+                                        const char *search_path)
+{
+        int tree_len;
+        int path_len;
+        char *tmp_path;
+
+        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);
+        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)
 {
@@ -161,41 +189,28 @@ int cifs_get_inode_info_unix(struct inode **pinode,
         struct cifsTconInfo *pTcon;
         struct inode *inode;
         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-        char *tmp_path;
+        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(pTcon, search_path);
+
+try_again_CIFSSMBUnixQPathInfo:
         /* could have done a find first instead but this returns more info */
-        rc = CIFSSMBUnixQPathInfo(xid, pTcon, search_path, &findData,
+        rc = CIFSSMBUnixQPathInfo(xid, pTcon, full_path, &findData,
                                   cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 /*      dump_mem("\nUnixQPathInfo return data", &findData,
                  sizeof(findData)); */
         if (rc) {
-                if (rc == -EREMOTE) {
-                        tmp_path =
-                            kmalloc(strnlen(pTcon->treeName,
-                                            MAX_TREE_SIZE + 1) +
-                                    strnlen(search_path, MAX_PATHCONF) + 1,
-                                    GFP_KERNEL);
-                        if (tmp_path == NULL)
-                                return -ENOMEM;
-
-                        /* have to skip first of the double backslash of
-                           UNC name */
-                        strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
-                        strncat(tmp_path, search_path, MAX_PATHCONF);
-                        rc = connect_to_dfs_path(xid, pTcon->ses,
-                                                 /* treename + */ tmp_path,
-                                                 cifs_sb->local_nls,
-                                                 cifs_sb->mnt_cifs_flags &
-                                                    CIFS_MOUNT_MAP_SPECIAL_CHR);
-                        kfree(tmp_path);
-
-                        /* BB fix up inode etc. */
-                } else if (rc) {
-                        return rc;
+                if (rc == -EREMOTE && !is_dfs_referral) {
+                        is_dfs_referral = true;
+                        full_path = search_path;
+                        goto try_again_CIFSSMBUnixQPathInfo;
                 }
+                goto cgiiu_exit;
         } else {
                 struct cifsInodeInfo *cifsInfo;
                 __u64 num_of_bytes = le64_to_cpu(findData.NumOfBytes);
@@ -204,8 +219,10 @@ int cifs_get_inode_info_unix(struct inode **pinode,
                 /* get new inode */
                 if (*pinode == NULL) {
                         *pinode = new_inode(sb);
-                        if (*pinode == NULL)
-                                return -ENOMEM;
+                        if (*pinode == NULL) {
+                                rc = -ENOMEM;
+                                goto cgiiu_exit;
+                        }
                         /* Is an i_ino of zero legal? */
                         /* Are there sanity checks we can use to ensure that
                            the server is really filling in that field? */
@@ -237,8 +254,11 @@ int cifs_get_inode_info_unix(struct inode **pinode,
                         (unsigned long) inode->i_size,
                         (unsigned long long)inode->i_blocks));
 
-                cifs_set_ops(inode);
+                cifs_set_ops(inode, is_dfs_referral);
         }
+cgiiu_exit:
+        if (full_path != search_path)
+                kfree(full_path);
         return rc;
 }
 
@@ -353,9 +373,10 @@ int cifs_get_inode_info(struct inode **pinode,
         struct cifsTconInfo *pTcon;
         struct inode *inode;
         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-        char *tmp_path;
+        const unsigned char *full_path = NULL;
         char *buf = NULL;
         int adjustTZ = FALSE;
+        bool is_dfs_referral = false;
 
         pTcon = cifs_sb->tcon;
         cFYI(1, ("Getting info on %s", search_path));
@@ -373,8 +394,12 @@ int cifs_get_inode_info(struct inode **pinode,
                 if (buf == NULL)
                         return -ENOMEM;
                 pfindData = (FILE_ALL_INFO *)buf;
+
+                full_path = cifs_get_search_path(pTcon, search_path);
+
+try_again_CIFSSMBQPathInfo:
                 /* could do find first instead but this returns more info */
-                rc = CIFSSMBQPathInfo(xid, pTcon, search_path, pfindData,
+                rc = CIFSSMBQPathInfo(xid, pTcon, full_path, pfindData,
                               0 /* not legacy */,
                               cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -382,7 +407,7 @@ int cifs_get_inode_info(struct inode **pinode,
                 when server claims no NT SMB support and the above call
                 failed at least once - set flag in tcon or mount */
                 if ((rc == -EOPNOTSUPP) || (rc == -EINVAL)) {
-                        rc = SMBQueryInformation(xid, pTcon, search_path,
+                        rc = SMBQueryInformation(xid, pTcon, full_path,
                                         pfindData, cifs_sb->local_nls,
                                         cifs_sb->mnt_cifs_flags &
                                           CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -391,31 +416,12 @@ int cifs_get_inode_info(struct inode **pinode,
         }
         /* dump_mem("\nQPathInfo return data",&findData, sizeof(findData)); */
         if (rc) {
-                if (rc == -EREMOTE) {
-                        tmp_path =
-                            kmalloc(strnlen
-                                    (pTcon->treeName,
-                                     MAX_TREE_SIZE + 1) +
-                                    strnlen(search_path, MAX_PATHCONF) + 1,
-                                    GFP_KERNEL);
-                        if (tmp_path == NULL) {
-                                kfree(buf);
-                                return -ENOMEM;
-                        }
-
-                        strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
-                        strncat(tmp_path, search_path, MAX_PATHCONF);
-                        rc = connect_to_dfs_path(xid, pTcon->ses,
-                                                 /* treename + */ tmp_path,
-                                                 cifs_sb->local_nls,
-                                                 cifs_sb->mnt_cifs_flags &
-                                                   CIFS_MOUNT_MAP_SPECIAL_CHR);
-                        kfree(tmp_path);
-                        /* BB fix up inode etc. */
-                } else if (rc) {
-                        kfree(buf);
-                        return rc;
+                if (rc == -EREMOTE && !is_dfs_referral) {
+                        is_dfs_referral = true;
+                        full_path = search_path;
+                        goto try_again_CIFSSMBQPathInfo;
                 }
+                goto cgii_exit;
         } else {
                 struct cifsInodeInfo *cifsInfo;
                 __u32 attr = le32_to_cpu(pfindData->Attributes);
@@ -424,8 +430,8 @@ int cifs_get_inode_info(struct inode **pinode,
                 if (*pinode == NULL) {
                         *pinode = new_inode(sb);
                         if (*pinode == NULL) {
-                                kfree(buf);
-                                return -ENOMEM;
+                                rc = -ENOMEM;
+                                goto cgii_exit;
                         }
                         /* Is an i_ino of zero legal? Can we use that to check
                            if the server supports returning inode numbers?  Are
@@ -573,8 +579,11 @@ int cifs_get_inode_info(struct inode **pinode,
                         atomic_set(&cifsInfo->inUse, 1);
                 }
 
-                cifs_set_ops(inode);
+                cifs_set_ops(inode, is_dfs_referral);
         }
+cgii_exit:
+        if (full_path != search_path)
+                kfree(full_path);
         kfree(buf);
         return rc;
 }
@@ -804,7 +813,7 @@ static void posix_fill_in_inode(struct inode *tmp_inode,
         local_size  = tmp_inode->i_size;
 
         cifs_unix_info_to_inode(tmp_inode, pData, 1);
-        cifs_set_ops(tmp_inode);
+        cifs_set_ops(tmp_inode, false);
 
         if (!S_ISREG(tmp_inode->i_mode))
                 return;