[CIFS] Readdir fixes to allow search to start at arbitrary position

in directory

Also includes first part of fix to compensate for servers which forget
to return . and .. as well as updates to changelog and cifs readme.

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

1 files changed, 22 insertions, 21 deletions

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 7b8591acc5ad..41c022e3c132 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -590,6 +590,13 @@ static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
         first_entry_in_buffer = 
                 cifsFile->srch_inf.index_of_last_entry - 
                         cifsFile->srch_inf.entries_in_buffer;
+
+        /* if first entry in buf is zero then is first buffer
+        in search response data which means it is likely . and ..
+        will be in this buffer, although some servers do not return
+        . and .. for the root of a drive and for those we need
+        to start two entries earlier */
+
 /*      dump_cifs_file_struct(file, "In fce ");*/
         if(((index_to_find < cifsFile->srch_inf.index_of_last_entry) && 
              is_dir_changed(file)) || 
@@ -632,23 +639,14 @@ static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
                 char * end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + 
                         smbCalcSize((struct smb_hdr *)
                                 cifsFile->srch_inf.ntwrk_buf_start);
+
+                current_entry = cifsFile->srch_inf.srch_entries_start;
                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
                                         - cifsFile->srch_inf.entries_in_buffer;
                 pos_in_buf = index_to_find - first_entry_in_buffer;
                 cFYI(1,("found entry - pos_in_buf %d",pos_in_buf)); 
-                current_entry = cifsFile->srch_inf.srch_entries_start;
                 for(i=0;(i<(pos_in_buf)) && (current_entry != NULL);i++) {
                         /* go entry by entry figuring out which is first */
-                        /* if( . or ..)
-                                skip */
-                        rc = cifs_entry_is_dot(current_entry,cifsFile);
-                        if(rc == 1) /* is . or .. so skip */ {
-                                cFYI(1,("Entry is .")); /* BB removeme BB */
-                                /* continue; */
-                        } else if (rc == 2 ) {
-                                cFYI(1,("Entry is ..")); /* BB removeme BB */
-                                /* continue; */
-                        }
                         current_entry = nxt_dir_entry(current_entry,end_of_smb);
                 }
                 if((current_entry == NULL) && (i < pos_in_buf)) {
@@ -768,6 +766,11 @@ static int cifs_filldir(char *pfindEntry, struct file *file,
         if(file->f_dentry == NULL)
                 return -ENOENT;
 
+        rc = cifs_entry_is_dot(pfindEntry,cifsF);
+        /* skip . and .. since we added them first */
+        if(rc != 0) 
+                return 0;
+
         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
 
         qstring.name = scratch_buf;
@@ -896,22 +899,22 @@ int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 
         switch ((int) file->f_pos) {
         case 0:
-                /*if (filldir(direntry, ".", 1, file->f_pos,
+                if (filldir(direntry, ".", 1, file->f_pos,
                      file->f_dentry->d_inode->i_ino, DT_DIR) < 0) {
-                        cERROR(1, ("Filldir for current dir failed "));
+                        cERROR(1, ("Filldir for current dir failed"));
                         rc = -ENOMEM;
                         break;
                 }
-                file->f_pos++; */
+                file->f_pos++;
         case 1:
-                /* if (filldir(direntry, "..", 2, file->f_pos,
+                if (filldir(direntry, "..", 2, file->f_pos,
                      file->f_dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
                         cERROR(1, ("Filldir for parent dir failed "));
                         rc = -ENOMEM;
                         break;
                 }
-                file->f_pos++; */
-        case 2:
+                file->f_pos++;
+        default:
                 /* 1) If search is active, 
                         is in current search buffer? 
                         if it before then restart search
@@ -925,7 +928,6 @@ int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
                                 return rc;
                         }
                 }
-        default:
                 if(file->private_data == NULL) {
                         rc = -EINVAL;
                         FreeXid(xid);
@@ -945,8 +947,6 @@ int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
                 kfree(cifsFile->search_resume_name);
                 cifsFile->search_resume_name = NULL; */
 
-                /* BB account for . and .. in f_pos as special case */
-
                 rc = find_cifs_entry(xid,pTcon, file,
                                 &current_entry,&num_to_fill);
                 if(rc) {
@@ -975,7 +975,8 @@ int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
                                           num_to_fill, i));
                                 break;
                         }
-
+                        /* if buggy server returns . and .. late do
+                        we want to check for that here? */
                         rc = cifs_filldir(current_entry, file, 
                                         filldir, direntry,tmp_buf);
                         file->f_pos++;